| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Peter Hurley | 11535 | 80.73% | 9 | 11.54% |
| Matwey V. Kornilov | 673 | 4.71% | 3 | 3.85% |
| Lukas Wunner | 447 | 3.13% | 9 | 11.54% |
| Thor Thayer | 191 | 1.34% | 1 | 1.28% |
| Andy Shevchenko | 183 | 1.28% | 13 | 16.67% |
| Rafael Gago | 165 | 1.15% | 1 | 1.28% |
| Joel Stanley | 147 | 1.03% | 2 | 2.56% |
| JiSheng Zhang | 119 | 0.83% | 3 | 3.85% |
| David Lechner | 98 | 0.69% | 1 | 1.28% |
| Masahiro Yamada | 94 | 0.66% | 1 | 1.28% |
| Yegor Yefremov | 86 | 0.60% | 3 | 3.85% |
| Phil Elwell | 86 | 0.60% | 2 | 2.56% |
| Måns Rullgård | 50 | 0.35% | 2 | 2.56% |
| Kai-Heng Feng | 48 | 0.34% | 1 | 1.28% |
| Vignesh R | 47 | 0.33% | 1 | 1.28% |
| Ed Blake | 46 | 0.32% | 2 | 2.56% |
| James Hogan | 45 | 0.31% | 1 | 1.28% |
| Marek Vašut | 41 | 0.29% | 2 | 2.56% |
| Wan Ahmad Zainie | 38 | 0.27% | 1 | 1.28% |
| Sean Wang | 35 | 0.24% | 1 | 1.28% |
| Taichi Kageyama | 20 | 0.14% | 1 | 1.28% |
| Ricardo Ribalda Delgado | 14 | 0.10% | 1 | 1.28% |
| Paul Burton | 10 | 0.07% | 1 | 1.28% |
| Josh Triplett | 9 | 0.06% | 1 | 1.28% |
| Dmitry Safonov | 9 | 0.06% | 1 | 1.28% |
| Sebastian Frias | 8 | 0.06% | 1 | 1.28% |
| Kimmo Rautkoski | 8 | 0.06% | 1 | 1.28% |
| Stefan Roese | 8 | 0.06% | 1 | 1.28% |
| Ard Biesheuvel | 6 | 0.04% | 1 | 1.28% |
| Jonathan McDowell | 5 | 0.03% | 1 | 1.28% |
| Jeremy Kerr | 5 | 0.03% | 1 | 1.28% |
| Anton Wuerfel | 3 | 0.02% | 1 | 1.28% |
| Jiri Olsa | 3 | 0.02% | 1 | 1.28% |
| Doug Anderson | 2 | 0.01% | 1 | 1.28% |
| Greg Kroah-Hartman | 2 | 0.01% | 2 | 2.56% |
| Christoph Hellwig | 1 | 0.01% | 1 | 1.28% |
| Jiri Slaby | 1 | 0.01% | 1 | 1.28% |
| Aaron Sierra | 1 | 0.01% | 1 | 1.28% |
| Total | 14289 | 78 |
// SPDX-License-Identifier: GPL-2.0+ /* * Base port operations for 8250/16550-type serial ports * * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. * Split from 8250_core.c, Copyright (C) 2001 Russell King. * * A note about mapbase / membase * * mapbase is the physical address of the IO port. * membase is an 'ioremapped' cookie. */ #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/ioport.h> #include <linux/init.h> #include <linux/console.h> #include <linux/sysrq.h> #include <linux/delay.h> #include <linux/platform_device.h> #include <linux/tty.h> #include <linux/ratelimit.h> #include <linux/tty_flip.h> #include <linux/serial.h> #include <linux/serial_8250.h> #include <linux/nmi.h> #include <linux/mutex.h> #include <linux/slab.h> #include <linux/uaccess.h> #include <linux/pm_runtime.h> #include <linux/ktime.h> #include <asm/io.h> #include <asm/irq.h> #include "8250.h" /* Nuvoton NPCM timeout register */ #define UART_NPCM_TOR 7 #define UART_NPCM_TOIE BIT(7) /* Timeout Interrupt Enable */ /* * Debugging. */ #if 0 #define DEBUG_AUTOCONF(fmt...) printk(fmt) #else #define DEBUG_AUTOCONF(fmt...) do { } while (0) #endif #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE) /* * Here we define the default xmit fifo size used for each type of UART. */ static const struct serial8250_config uart_config[] = { [PORT_UNKNOWN] = { .name = "unknown", .fifo_size = 1, .tx_loadsz = 1, }, [PORT_8250] = { .name = "8250", .fifo_size = 1, .tx_loadsz = 1, }, [PORT_16450] = { .name = "16450", .fifo_size = 1, .tx_loadsz = 1, }, [PORT_16550] = { .name = "16550", .fifo_size = 1, .tx_loadsz = 1, }, [PORT_16550A] = { .name = "16550A", .fifo_size = 16, .tx_loadsz = 16, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .rxtrig_bytes = {1, 4, 8, 14}, .flags = UART_CAP_FIFO, }, [PORT_CIRRUS] = { .name = "Cirrus", .fifo_size = 1, .tx_loadsz = 1, }, [PORT_16650] = { .name = "ST16650", .fifo_size = 1, .tx_loadsz = 1, .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP, }, [PORT_16650V2] = { .name = "ST16650V2", .fifo_size = 32, .tx_loadsz = 16, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 | UART_FCR_T_TRIG_00, .rxtrig_bytes = {8, 16, 24, 28}, .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP, }, [PORT_16750] = { .name = "TI16750", .fifo_size = 64, .tx_loadsz = 64, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 | UART_FCR7_64BYTE, .rxtrig_bytes = {1, 16, 32, 56}, .flags = UART_CAP_FIFO | UART_CAP_SLEEP | UART_CAP_AFE, }, [PORT_STARTECH] = { .name = "Startech", .fifo_size = 1, .tx_loadsz = 1, }, [PORT_16C950] = { .name = "16C950/954", .fifo_size = 128, .tx_loadsz = 128, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, /* UART_CAP_EFR breaks billionon CF bluetooth card. */ .flags = UART_CAP_FIFO | UART_CAP_SLEEP, }, [PORT_16654] = { .name = "ST16654", .fifo_size = 64, .tx_loadsz = 32, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 | UART_FCR_T_TRIG_10, .rxtrig_bytes = {8, 16, 56, 60}, .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP, }, [PORT_16850] = { .name = "XR16850", .fifo_size = 128, .tx_loadsz = 128, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .flags = UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP, }, [PORT_RSA] = { .name = "RSA", .fifo_size = 2048, .tx_loadsz = 2048, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_11, .flags = UART_CAP_FIFO, }, [PORT_NS16550A] = { .name = "NS16550A", .fifo_size = 16, .tx_loadsz = 16, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .flags = UART_CAP_FIFO | UART_NATSEMI, }, [PORT_XSCALE] = { .name = "XScale", .fifo_size = 32, .tx_loadsz = 32, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .flags = UART_CAP_FIFO | UART_CAP_UUE | UART_CAP_RTOIE, }, [PORT_OCTEON] = { .name = "OCTEON", .fifo_size = 64, .tx_loadsz = 64, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .flags = UART_CAP_FIFO, }, [PORT_AR7] = { .name = "AR7", .fifo_size = 16, .tx_loadsz = 16, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_00, .flags = UART_CAP_FIFO /* | UART_CAP_AFE */, }, [PORT_U6_16550A] = { .name = "U6_16550A", .fifo_size = 64, .tx_loadsz = 64, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .flags = UART_CAP_FIFO | UART_CAP_AFE, }, [PORT_TEGRA] = { .name = "Tegra", .fifo_size = 32, .tx_loadsz = 8, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 | UART_FCR_T_TRIG_01, .rxtrig_bytes = {1, 4, 8, 14}, .flags = UART_CAP_FIFO | UART_CAP_RTOIE, }, [PORT_XR17D15X] = { .name = "XR17D15X", .fifo_size = 64, .tx_loadsz = 64, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .flags = UART_CAP_FIFO | UART_CAP_AFE | UART_CAP_EFR | UART_CAP_SLEEP, }, [PORT_XR17V35X] = { .name = "XR17V35X", .fifo_size = 256, .tx_loadsz = 256, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_11 | UART_FCR_T_TRIG_11, .flags = UART_CAP_FIFO | UART_CAP_AFE | UART_CAP_EFR | UART_CAP_SLEEP, }, [PORT_LPC3220] = { .name = "LPC3220", .fifo_size = 64, .tx_loadsz = 32, .fcr = UART_FCR_DMA_SELECT | UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_00 | UART_FCR_T_TRIG_00, .flags = UART_CAP_FIFO, }, [PORT_BRCM_TRUMANAGE] = { .name = "TruManage", .fifo_size = 1, .tx_loadsz = 1024, .flags = UART_CAP_HFIFO, }, [PORT_8250_CIR] = { .name = "CIR port" }, [PORT_ALTR_16550_F32] = { .name = "Altera 16550 FIFO32", .fifo_size = 32, .tx_loadsz = 32, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .rxtrig_bytes = {1, 8, 16, 30}, .flags = UART_CAP_FIFO | UART_CAP_AFE, }, [PORT_ALTR_16550_F64] = { .name = "Altera 16550 FIFO64", .fifo_size = 64, .tx_loadsz = 64, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .rxtrig_bytes = {1, 16, 32, 62}, .flags = UART_CAP_FIFO | UART_CAP_AFE, }, [PORT_ALTR_16550_F128] = { .name = "Altera 16550 FIFO128", .fifo_size = 128, .tx_loadsz = 128, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .rxtrig_bytes = {1, 32, 64, 126}, .flags = UART_CAP_FIFO | UART_CAP_AFE, }, /* * tx_loadsz is set to 63-bytes instead of 64-bytes to implement * workaround of errata A-008006 which states that tx_loadsz should * be configured less than Maximum supported fifo bytes. */ [PORT_16550A_FSL64] = { .name = "16550A_FSL64", .fifo_size = 64, .tx_loadsz = 63, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 | UART_FCR7_64BYTE, .flags = UART_CAP_FIFO, }, [PORT_RT2880] = { .name = "Palmchip BK-3103", .fifo_size = 16, .tx_loadsz = 16, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .rxtrig_bytes = {1, 4, 8, 14}, .flags = UART_CAP_FIFO, }, [PORT_DA830] = { .name = "TI DA8xx/66AK2x", .fifo_size = 16, .tx_loadsz = 16, .fcr = UART_FCR_DMA_SELECT | UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .rxtrig_bytes = {1, 4, 8, 14}, .flags = UART_CAP_FIFO | UART_CAP_AFE, }, [PORT_MTK_BTIF] = { .name = "MediaTek BTIF", .fifo_size = 16, .tx_loadsz = 16, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT, .flags = UART_CAP_FIFO, }, [PORT_NPCM] = { .name = "Nuvoton 16550", .fifo_size = 16, .tx_loadsz = 16, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT, .rxtrig_bytes = {1, 4, 8, 14}, .flags = UART_CAP_FIFO, }, [PORT_SUNIX] = { .name = "Sunix", .fifo_size = 128, .tx_loadsz = 128, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .rxtrig_bytes = {1, 32, 64, 112}, .flags = UART_CAP_FIFO | UART_CAP_SLEEP, }, }; /* Uart divisor latch read */ static int default_serial_dl_read(struct uart_8250_port *up) { return serial_in(up, UART_DLL) | serial_in(up, UART_DLM) << 8; } /* Uart divisor latch write */ static void default_serial_dl_write(struct uart_8250_port *up, int value) { serial_out(up, UART_DLL, value & 0xff); serial_out(up, UART_DLM, value >> 8 & 0xff); } #ifdef CONFIG_SERIAL_8250_RT288X /* Au1x00/RT288x UART hardware has a weird register layout */ static const s8 au_io_in_map[8] = { 0, /* UART_RX */ 2, /* UART_IER */ 3, /* UART_IIR */ 5, /* UART_LCR */ 6, /* UART_MCR */ 7, /* UART_LSR */ 8, /* UART_MSR */ -1, /* UART_SCR (unmapped) */ }; static const s8 au_io_out_map[8] = { 1, /* UART_TX */ 2, /* UART_IER */ 4, /* UART_FCR */ 5, /* UART_LCR */ 6, /* UART_MCR */ -1, /* UART_LSR (unmapped) */ -1, /* UART_MSR (unmapped) */ -1, /* UART_SCR (unmapped) */ }; unsigned int au_serial_in(struct uart_port *p, int offset) { if (offset >= ARRAY_SIZE(au_io_in_map)) return UINT_MAX; offset = au_io_in_map[offset]; if (offset < 0) return UINT_MAX; return __raw_readl(p->membase + (offset << p->regshift)); } void au_serial_out(struct uart_port *p, int offset, int value) { if (offset >= ARRAY_SIZE(au_io_out_map)) return; offset = au_io_out_map[offset]; if (offset < 0) return; __raw_writel(value, p->membase + (offset << p->regshift)); } /* Au1x00 haven't got a standard divisor latch */ static int au_serial_dl_read(struct uart_8250_port *up) { return __raw_readl(up->port.membase + 0x28); } static void au_serial_dl_write(struct uart_8250_port *up, int value) { __raw_writel(value, up->port.membase + 0x28); } #endif static unsigned int hub6_serial_in(struct uart_port *p, int offset) { offset = offset << p->regshift; outb(p->hub6 - 1 + offset, p->iobase); return inb(p->iobase + 1); } static void hub6_serial_out(struct uart_port *p, int offset, int value) { offset = offset << p->regshift; outb(p->hub6 - 1 + offset, p->iobase); outb(value, p->iobase + 1); } static unsigned int mem_serial_in(struct uart_port *p, int offset) { offset = offset << p->regshift; return readb(p->membase + offset); } static void mem_serial_out(struct uart_port *p, int offset, int value) { offset = offset << p->regshift; writeb(value, p->membase + offset); } static void mem16_serial_out(struct uart_port *p, int offset, int value) { offset = offset << p->regshift; writew(value, p->membase + offset); } static unsigned int mem16_serial_in(struct uart_port *p, int offset) { offset = offset << p->regshift; return readw(p->membase + offset); } static void mem32_serial_out(struct uart_port *p, int offset, int value) { offset = offset << p->regshift; writel(value, p->membase + offset); } static unsigned int mem32_serial_in(struct uart_port *p, int offset) { offset = offset << p->regshift; return readl(p->membase + offset); } static void mem32be_serial_out(struct uart_port *p, int offset, int value) { offset = offset << p->regshift; iowrite32be(value, p->membase + offset); } static unsigned int mem32be_serial_in(struct uart_port *p, int offset) { offset = offset << p->regshift; return ioread32be(p->membase + offset); } static unsigned int io_serial_in(struct uart_port *p, int offset) { offset = offset << p->regshift; return inb(p->iobase + offset); } static void io_serial_out(struct uart_port *p, int offset, int value) { offset = offset << p->regshift; outb(value, p->iobase + offset); } static int serial8250_default_handle_irq(struct uart_port *port); static void set_io_from_upio(struct uart_port *p) { struct uart_8250_port *up = up_to_u8250p(p); up->dl_read = default_serial_dl_read; up->dl_write = default_serial_dl_write; switch (p->iotype) { case UPIO_HUB6: p->serial_in = hub6_serial_in; p->serial_out = hub6_serial_out; break; case UPIO_MEM: p->serial_in = mem_serial_in; p->serial_out = mem_serial_out; break; case UPIO_MEM16: p->serial_in = mem16_serial_in; p->serial_out = mem16_serial_out; break; case UPIO_MEM32: p->serial_in = mem32_serial_in; p->serial_out = mem32_serial_out; break; case UPIO_MEM32BE: p->serial_in = mem32be_serial_in; p->serial_out = mem32be_serial_out; break; #ifdef CONFIG_SERIAL_8250_RT288X case UPIO_AU: p->serial_in = au_serial_in; p->serial_out = au_serial_out; up->dl_read = au_serial_dl_read; up->dl_write = au_serial_dl_write; break; #endif default: p->serial_in = io_serial_in; p->serial_out = io_serial_out; break; } /* Remember loaded iotype */ up->cur_iotype = p->iotype; p->handle_irq = serial8250_default_handle_irq; } static void serial_port_out_sync(struct uart_port *p, int offset, int value) { switch (p->iotype) { case UPIO_MEM: case UPIO_MEM16: case UPIO_MEM32: case UPIO_MEM32BE: case UPIO_AU: p->serial_out(p, offset, value); p->serial_in(p, UART_LCR); /* safe, no side-effects */ break; default: p->serial_out(p, offset, value); } } /* * For the 16C950 */ static void serial_icr_write(struct uart_8250_port *up, int offset, int value) { serial_out(up, UART_SCR, offset); serial_out(up, UART_ICR, value); } static unsigned int serial_icr_read(struct uart_8250_port *up, int offset) { unsigned int value; serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD); serial_out(up, UART_SCR, offset); value = serial_in(up, UART_ICR); serial_icr_write(up, UART_ACR, up->acr); return value; } /* * FIFO support. */ static void serial8250_clear_fifos(struct uart_8250_port *p) { if (p->capabilities & UART_CAP_FIFO) { serial_out(p, UART_FCR, UART_FCR_ENABLE_FIFO); serial_out(p, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT); serial_out(p, UART_FCR, 0); } } static enum hrtimer_restart serial8250_em485_handle_start_tx(struct hrtimer *t); static enum hrtimer_restart serial8250_em485_handle_stop_tx(struct hrtimer *t); void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p) { serial8250_clear_fifos(p); serial_out(p, UART_FCR, p->fcr); } EXPORT_SYMBOL_GPL(serial8250_clear_and_reinit_fifos); void serial8250_rpm_get(struct uart_8250_port *p) { if (!(p->capabilities & UART_CAP_RPM)) return; pm_runtime_get_sync(p->port.dev); } EXPORT_SYMBOL_GPL(serial8250_rpm_get); void serial8250_rpm_put(struct uart_8250_port *p) { if (!(p->capabilities & UART_CAP_RPM)) return; pm_runtime_mark_last_busy(p->port.dev); pm_runtime_put_autosuspend(p->port.dev); } EXPORT_SYMBOL_GPL(serial8250_rpm_put); /** * serial8250_em485_init() - put uart_8250_port into rs485 emulating * @p: uart_8250_port port instance * * The function is used to start rs485 software emulating on the * &struct uart_8250_port* @p. Namely, RTS is switched before/after * transmission. The function is idempotent, so it is safe to call it * multiple times. * * The caller MUST enable interrupt on empty shift register before * calling serial8250_em485_init(). This interrupt is not a part of * 8250 standard, but implementation defined. * * The function is supposed to be called from .rs485_config callback * or from any other callback protected with p->port.lock spinlock. * * See also serial8250_em485_destroy() * * Return 0 - success, -errno - otherwise */ static int serial8250_em485_init(struct uart_8250_port *p) { if (p->em485) return 0; p->em485 = kmalloc(sizeof(struct uart_8250_em485), GFP_ATOMIC); if (!p->em485) return -ENOMEM; hrtimer_init(&p->em485->stop_tx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); hrtimer_init(&p->em485->start_tx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); p->em485->stop_tx_timer.function = &serial8250_em485_handle_stop_tx; p->em485->start_tx_timer.function = &serial8250_em485_handle_start_tx; p->em485->port = p; p->em485->active_timer = NULL; p->em485->tx_stopped = true; p->rs485_stop_tx(p); return 0; } /** * serial8250_em485_destroy() - put uart_8250_port into normal state * @p: uart_8250_port port instance * * The function is used to stop rs485 software emulating on the * &struct uart_8250_port* @p. The function is idempotent, so it is safe to * call it multiple times. * * The function is supposed to be called from .rs485_config callback * or from any other callback protected with p->port.lock spinlock. * * See also serial8250_em485_init() */ void serial8250_em485_destroy(struct uart_8250_port *p) { if (!p->em485) return; hrtimer_cancel(&p->em485->start_tx_timer); hrtimer_cancel(&p->em485->stop_tx_timer); kfree(p->em485); p->em485 = NULL; } EXPORT_SYMBOL_GPL(serial8250_em485_destroy); /** * serial8250_em485_config() - generic ->rs485_config() callback * @port: uart port * @rs485: rs485 settings * * Generic callback usable by 8250 uart drivers to activate rs485 settings * if the uart is incapable of driving RTS as a Transmit Enable signal in * hardware, relying on software emulation instead. */ int serial8250_em485_config(struct uart_port *port, struct serial_rs485 *rs485) { struct uart_8250_port *up = up_to_u8250p(port); /* pick sane settings if the user hasn't */ if (!!(rs485->flags & SER_RS485_RTS_ON_SEND) == !!(rs485->flags & SER_RS485_RTS_AFTER_SEND)) { rs485->flags |= SER_RS485_RTS_ON_SEND; rs485->flags &= ~SER_RS485_RTS_AFTER_SEND; } /* clamp the delays to [0, 100ms] */ rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U); rs485->delay_rts_after_send = min(rs485->delay_rts_after_send, 100U); memset(rs485->padding, 0, sizeof(rs485->padding)); port->rs485 = *rs485; /* * Both serial8250_em485_init() and serial8250_em485_destroy() * are idempotent. */ if (rs485->flags & SER_RS485_ENABLED) { int ret = serial8250_em485_init(up); if (ret) { rs485->flags &= ~SER_RS485_ENABLED; port->rs485.flags &= ~SER_RS485_ENABLED; } return ret; } serial8250_em485_destroy(up); return 0; } EXPORT_SYMBOL_GPL(serial8250_em485_config); /* * These two wrappers ensure that enable_runtime_pm_tx() can be called more than * once and disable_runtime_pm_tx() will still disable RPM because the fifo is * empty and the HW can idle again. */ void serial8250_rpm_get_tx(struct uart_8250_port *p) { unsigned char rpm_active; if (!(p->capabilities & UART_CAP_RPM)) return; rpm_active = xchg(&p->rpm_tx_active, 1); if (rpm_active) return; pm_runtime_get_sync(p->port.dev); } EXPORT_SYMBOL_GPL(serial8250_rpm_get_tx); void serial8250_rpm_put_tx(struct uart_8250_port *p) { unsigned char rpm_active; if (!(p->capabilities & UART_CAP_RPM)) return; rpm_active = xchg(&p->rpm_tx_active, 0); if (!rpm_active) return; pm_runtime_mark_last_busy(p->port.dev); pm_runtime_put_autosuspend(p->port.dev); } EXPORT_SYMBOL_GPL(serial8250_rpm_put_tx); /* * IER sleep support. UARTs which have EFRs need the "extended * capability" bit enabled. Note that on XR16C850s, we need to * reset LCR to write to IER. */ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep) { unsigned char lcr = 0, efr = 0; serial8250_rpm_get(p); if (p->capabilities & UART_CAP_SLEEP) { if (p->capabilities & UART_CAP_EFR) { lcr = serial_in(p, UART_LCR); efr = serial_in(p, UART_EFR); serial_out(p, UART_LCR, UART_LCR_CONF_MODE_B); serial_out(p, UART_EFR, UART_EFR_ECB); serial_out(p, UART_LCR, 0); } serial_out(p, UART_IER, sleep ? UART_IERX_SLEEP : 0); if (p->capabilities & UART_CAP_EFR) { serial_out(p, UART_LCR, UART_LCR_CONF_MODE_B); serial_out(p, UART_EFR, efr); serial_out(p, UART_LCR, lcr); } } serial8250_rpm_put(p); } #ifdef CONFIG_SERIAL_8250_RSA /* * Attempts to turn on the RSA FIFO. Returns zero on failure. * We set the port uart clock rate if we succeed. */ static int __enable_rsa(struct uart_8250_port *up) { unsigned char mode; int result; mode = serial_in(up, UART_RSA_MSR); result = mode & UART_RSA_MSR_FIFO; if (!result) { serial_out(up, UART_RSA_MSR, mode | UART_RSA_MSR_FIFO); mode = serial_in(up, UART_RSA_MSR); result = mode & UART_RSA_MSR_FIFO; } if (result) up->port.uartclk = SERIAL_RSA_BAUD_BASE * 16; return result; } static void enable_rsa(struct uart_8250_port *up) { if (up->port.type == PORT_RSA) { if (up->port.uartclk != SERIAL_RSA_BAUD_BASE * 16) { spin_lock_irq(&up->port.lock); __enable_rsa(up); spin_unlock_irq(&up->port.lock); } if (up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) serial_out(up, UART_RSA_FRR, 0); } } /* * Attempts to turn off the RSA FIFO. Returns zero on failure. * It is unknown why interrupts were disabled in here. However, * the caller is expected to preserve this behaviour by grabbing * the spinlock before calling this function. */ static void disable_rsa(struct uart_8250_port *up) { unsigned char mode; int result; if (up->port.type == PORT_RSA && up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) { spin_lock_irq(&up->port.lock); mode = serial_in(up, UART_RSA_MSR); result = !(mode & UART_RSA_MSR_FIFO); if (!result) { serial_out(up, UART_RSA_MSR, mode & ~UART_RSA_MSR_FIFO); mode = serial_in(up, UART_RSA_MSR); result = !(mode & UART_RSA_MSR_FIFO); } if (result) up->port.uartclk = SERIAL_RSA_BAUD_BASE_LO * 16; spin_unlock_irq(&up->port.lock); } } #endif /* CONFIG_SERIAL_8250_RSA */ /* * This is a quickie test to see how big the FIFO is. * It doesn't work at all the time, more's the pity. */ static int size_fifo(struct uart_8250_port *up) { unsigned char old_fcr, old_mcr, old_lcr; unsigned short old_dl; int count; old_lcr = serial_in(up, UART_LCR); serial_out(up, UART_LCR, 0); old_fcr = serial_in(up, UART_FCR); old_mcr = serial8250_in_MCR(up); serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT); serial8250_out_MCR(up, UART_MCR_LOOP); serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A); old_dl = serial_dl_read(up); serial_dl_write(up, 0x0001); serial_out(up, UART_LCR, 0x03); for (count = 0; count < 256; count++) serial_out(up, UART_TX, count); mdelay(20);/* FIXME - schedule_timeout */ for (count = 0; (serial_in(up, UART_LSR) & UART_LSR_DR) && (count < 256); count++) serial_in(up, UART_RX); serial_out(up, UART_FCR, old_fcr); serial8250_out_MCR(up, old_mcr); serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A); serial_dl_write(up, old_dl); serial_out(up, UART_LCR, old_lcr); return count; } /* * Read UART ID using the divisor method - set DLL and DLM to zero * and the revision will be in DLL and device type in DLM. We * preserve the device state across this. */ static unsigned int autoconfig_read_divisor_id(struct uart_8250_port *p) { unsigned char old_lcr; unsigned int id, old_dl; old_lcr = serial_in(p, UART_LCR); serial_out(p, UART_LCR, UART_LCR_CONF_MODE_A); old_dl = serial_dl_read(p); serial_dl_write(p, 0); id = serial_dl_read(p); serial_dl_write(p, old_dl); serial_out(p, UART_LCR, old_lcr); return id; } /* * This is a helper routine to autodetect StarTech/Exar/Oxsemi UART's. * When this function is called we know it is at least a StarTech * 16650 V2, but it might be one of several StarTech UARTs, or one of * its clones. (We treat the broken original StarTech 16650 V1 as a * 16550, and why not? Startech doesn't seem to even acknowledge its * existence.) * * What evil have men's minds wrought... */ static void autoconfig_has_efr(struct uart_8250_port *up) { unsigned int id1, id2, id3, rev; /* * Everything with an EFR has SLEEP */ up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP; /* * First we check to see if it's an Oxford Semiconductor UART. * * If we have to do this here because some non-National * Semiconductor clone chips lock up if you try writing to the * LSR register (which serial_icr_read does) */ /* * Check for Oxford Semiconductor 16C950. * * EFR [4] must be set else this test fails. * * This shouldn't be necessary, but Mike Hudson (Exoray@isys.ca) * claims that it's needed for 952 dual UART's (which are not * recommended for new designs). */ up->acr = 0; serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); serial_out(up, UART_EFR, UART_EFR_ECB); serial_out(up, UART_LCR, 0x00); id1 = serial_icr_read(up, UART_ID1); id2 = serial_icr_read(up, UART_ID2); id3 = serial_icr_read(up, UART_ID3); rev = serial_icr_read(up, UART_REV); DEBUG_AUTOCONF("950id=%02x:%02x:%02x:%02x ", id1, id2, id3, rev); if (id1 == 0x16 && id2 == 0xC9 && (id3 == 0x50 || id3 == 0x52 || id3 == 0x54)) { up->port.type = PORT_16C950; /* * Enable work around for the Oxford Semiconductor 952 rev B * chip which causes it to seriously miscalculate baud rates * when DLL is 0. */ if (id3 == 0x52 && rev == 0x01) up->bugs |= UART_BUG_QUOT; return; } /* * We check for a XR16C850 by setting DLL and DLM to 0, and then * reading back DLL and DLM. The chip type depends on the DLM * value read back: * 0x10 - XR16C850 and the DLL contains the chip revision. * 0x12 - XR16C2850. * 0x14 - XR16C854. */ id1 = autoconfig_read_divisor_id(up); DEBUG_AUTOCONF("850id=%04x ", id1); id2 = id1 >> 8; if (id2 == 0x10 || id2 == 0x12 || id2 == 0x14) { up->port.type = PORT_16850; return; } /* * It wasn't an XR16C850. * * We distinguish between the '654 and the '650 by counting * how many bytes are in the FIFO. I'm using this for now, * since that's the technique that was sent to me in the * serial driver update, but I'm not convinced this works. * I've had problems doing this in the past. -TYT */ if (size_fifo(up) == 64) up->port.type = PORT_16654; else up->port.type = PORT_16650V2; } /* * We detected a chip without a FIFO. Only two fall into * this category - the original 8250 and the 16450. The * 16450 has a scratch register (accessible with LCR=0) */ static void autoconfig_8250(struct uart_8250_port *up) { unsigned char scratch, status1, status2; up->port.type = PORT_8250; scratch = serial_in(up, UART_SCR); serial_out(up, UART_SCR, 0xa5); status1 = serial_in(up, UART_SCR); serial_out(up, UART_SCR, 0x5a); status2 = serial_in(up, UART_SCR); serial_out(up, UART_SCR, scratch); if (status1 == 0xa5 && status2 == 0x5a) up->port.type = PORT_16450; } static int broken_efr(struct uart_8250_port *up) { /* * Exar ST16C2550 "A2" devices incorrectly detect as * having an EFR, and report an ID of 0x0201. See * http://linux.derkeiler.com/Mailing-Lists/Kernel/2004-11/4812.html */ if (autoconfig_read_divisor_id(up) == 0x0201 && size_fifo(up) == 16) return 1; return 0; } /* * We know that the chip has FIFOs. Does it have an EFR? The * EFR is located in the same register position as the IIR and * we know the top two bits of the IIR are currently set. The * EFR should contain zero. Try to read the EFR. */ static void autoconfig_16550a(struct uart_8250_port *up) { unsigned char status1, status2; unsigned int iersave; up->port.type = PORT_16550A; up->capabilities |= UART_CAP_FIFO; if (!IS_ENABLED(CONFIG_SERIAL_8250_16550A_VARIANTS)) return; /* * Check for presence of the EFR when DLAB is set. * Only ST16C650V1 UARTs pass this test. */ serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A); if (serial_in(up, UART_EFR) == 0) { serial_out(up, UART_EFR, 0xA8); if (serial_in(up, UART_EFR) != 0) { DEBUG_AUTOCONF("EFRv1 "); up->port.type = PORT_16650; up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP; } else { serial_out(up, UART_LCR, 0); serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE); status1 = serial_in(up, UART_IIR) >> 5; serial_out(up, UART_FCR, 0); serial_out(up, UART_LCR, 0); if (status1 == 7) up->port.type = PORT_16550A_FSL64; else DEBUG_AUTOCONF("Motorola 8xxx DUART "); } serial_out(up, UART_EFR, 0); return; } /* * Maybe it requires 0xbf to be written to the LCR. * (other ST16C650V2 UARTs, TI16C752A, etc) */ serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); if (serial_in(up, UART_EFR) == 0 && !broken_efr(up)) { DEBUG_AUTOCONF("EFRv2 "); autoconfig_has_efr(up); return; } /* * Check for a National Semiconductor SuperIO chip. * Attempt to switch to bank 2, read the value of the LOOP bit * from EXCR1. Switch back to bank 0, change it in MCR. Then * switch back to bank 2, read it from EXCR1 again and check * it's changed. If so, set baud_base in EXCR2 to 921600. -- dwmw2 */ serial_out(up, UART_LCR, 0); status1 = serial8250_in_MCR(up); serial_out(up, UART_LCR, 0xE0); status2 = serial_in(up, 0x02); /* EXCR1 */ if (!((status2 ^ status1) & UART_MCR_LOOP)) { serial_out(up, UART_LCR, 0); serial8250_out_MCR(up, status1 ^ UART_MCR_LOOP); serial_out(up, UART_LCR, 0xE0); status2 = serial_in(up, 0x02); /* EXCR1 */ serial_out(up, UART_LCR, 0); serial8250_out_MCR(up, status1); if ((status2 ^ status1) & UART_MCR_LOOP) { unsigned short quot; serial_out(up, UART_LCR, 0xE0); quot = serial_dl_read(up); quot <<= 3; if (ns16550a_goto_highspeed(up)) serial_dl_write(up, quot); serial_out(up, UART_LCR, 0); up->port.uartclk = 921600*16; up->port.type = PORT_NS16550A; up->capabilities |= UART_NATSEMI; return; } } /* * No EFR. Try to detect a TI16750, which only sets bit 5 of * the IIR when 64 byte FIFO mode is enabled when DLAB is set. * Try setting it with and without DLAB set. Cheap clones * set bit 5 without DLAB set. */ serial_out(up, UART_LCR, 0); serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE); status1 = serial_in(up, UART_IIR) >> 5; serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO); serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A); serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE); status2 = serial_in(up, UART_IIR) >> 5; serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO); serial_out(up, UART_LCR, 0); DEBUG_AUTOCONF("iir1=%d iir2=%d ", status1, status2); if (status1 == 6 && status2 == 7) { up->port.type = PORT_16750; up->capabilities |= UART_CAP_AFE | UART_CAP_SLEEP; return; } /* * Try writing and reading the UART_IER_UUE bit (b6). * If it works, this is probably one of the Xscale platform's * internal UARTs. * We're going to explicitly set the UUE bit to 0 before * trying to write and read a 1 just to make sure it's not * already a 1 and maybe locked there before we even start start. */ iersave = serial_in(up, UART_IER); serial_out(up, UART_IER, iersave & ~UART_IER_UUE); if (!(serial_in(up, UART_IER) & UART_IER_UUE)) { /* * OK it's in a known zero state, try writing and reading * without disturbing the current state of the other bits. */ serial_out(up, UART_IER, iersave | UART_IER_UUE); if (serial_in(up, UART_IER) & UART_IER_UUE) { /* * It's an Xscale. * We'll leave the UART_IER_UUE bit set to 1 (enabled). */ DEBUG_AUTOCONF("Xscale "); up->port.type = PORT_XSCALE; up->capabilities |= UART_CAP_UUE | UART_CAP_RTOIE; return; } } else { /* * If we got here we couldn't force the IER_UUE bit to 0. * Log it and continue. */ DEBUG_AUTOCONF("Couldn't force IER_UUE to 0 "); } serial_out(up, UART_IER, iersave); /* * We distinguish between 16550A and U6 16550A by counting * how many bytes are in the FIFO. */ if (up->port.type == PORT_16550A && size_fifo(up) == 64) { up->port.type = PORT_U6_16550A; up->capabilities |= UART_CAP_AFE; } } /* * This routine is called by rs_init() to initialize a specific serial * port. It determines what type of UART chip this serial port is * using: 8250, 16450, 16550, 16550A. The important question is * whether or not this UART is a 16550A or not, since this will * determine whether or not we can use its FIFO features or not. */ static void autoconfig(struct uart_8250_port *up) { unsigned char status1, scratch, scratch2, scratch3; unsigned char save_lcr, save_mcr; struct uart_port *port = &up->port; unsigned long flags; unsigned int old_capabilities; if (!port->iobase && !port->mapbase && !port->membase) return; DEBUG_AUTOCONF("%s: autoconf (0x%04lx, 0x%p): ", port->name, port->iobase, port->membase); /* * We really do need global IRQs disabled here - we're going to * be frobbing the chips IRQ enable register to see if it exists. */ spin_lock_irqsave(&port->lock, flags); up->capabilities = 0; up->bugs = 0; if (!(port->flags & UPF_BUGGY_UART)) { /* * Do a simple existence test first; if we fail this, * there's no point trying anything else. * * 0x80 is used as a nonsense port to prevent against * false positives due to ISA bus float. The * assumption is that 0x80 is a non-existent port; * which should be safe since include/asm/io.h also * makes this assumption. * * Note: this is safe as long as MCR bit 4 is clear * and the device is in "PC" mode. */ scratch = serial_in(up, UART_IER); serial_out(up, UART_IER, 0); #ifdef __i386__ outb(0xff, 0x080); #endif /* * Mask out IER[7:4] bits for test as some UARTs (e.g. TL * 16C754B) allow only to modify them if an EFR bit is set. */ scratch2 = serial_in(up, UART_IER) & 0x0f; serial_out(up, UART_IER, 0x0F); #ifdef __i386__ outb(0, 0x080); #endif scratch3 = serial_in(up, UART_IER) & 0x0f; serial_out(up, UART_IER, scratch); if (scratch2 != 0 || scratch3 != 0x0F) { /* * We failed; there's nothing here */ spin_unlock_irqrestore(&port->lock, flags); DEBUG_AUTOCONF("IER test failed (%02x, %02x) ", scratch2, scratch3); goto out; } } save_mcr = serial8250_in_MCR(up); save_lcr = serial_in(up, UART_LCR); /* * Check to see if a UART is really there. Certain broken * internal modems based on the Rockwell chipset fail this * test, because they apparently don't implement the loopback * test mode. So this test is skipped on the COM 1 through * COM 4 ports. This *should* be safe, since no board * manufacturer would be stupid enough to design a board * that conflicts with COM 1-4 --- we hope! */ if (!(port->flags & UPF_SKIP_TEST)) { serial8250_out_MCR(up, UART_MCR_LOOP | 0x0A); status1 = serial_in(up, UART_MSR) & 0xF0; serial8250_out_MCR(up, save_mcr); if (status1 != 0x90) { spin_unlock_irqrestore(&port->lock, flags); DEBUG_AUTOCONF("LOOP test failed (%02x) ", status1); goto out; } } /* * We're pretty sure there's a port here. Lets find out what * type of port it is. The IIR top two bits allows us to find * out if it's 8250 or 16450, 16550, 16550A or later. This * determines what we test for next. * * We also initialise the EFR (if any) to zero for later. The * EFR occupies the same register location as the FCR and IIR. */ serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); serial_out(up, UART_EFR, 0); serial_out(up, UART_LCR, 0); serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO); scratch = serial_in(up, UART_IIR) >> 6; switch (scratch) { case 0: autoconfig_8250(up); break; case 1: port->type = PORT_UNKNOWN; break; case 2: port->type = PORT_16550; break; case 3: autoconfig_16550a(up); break; } #ifdef CONFIG_SERIAL_8250_RSA /* * Only probe for RSA ports if we got the region. */ if (port->type == PORT_16550A && up->probe & UART_PROBE_RSA && __enable_rsa(up)) port->type = PORT_RSA; #endif serial_out(up, UART_LCR, save_lcr); port->fifosize = uart_config[up->port.type].fifo_size; old_capabilities = up->capabilities; up->capabilities = uart_config[port->type].flags; up->tx_loadsz = uart_config[port->type].tx_loadsz; if (port->type == PORT_UNKNOWN) goto out_lock; /* * Reset the UART. */ #ifdef CONFIG_SERIAL_8250_RSA if (port->type == PORT_RSA) serial_out(up, UART_RSA_FRR, 0); #endif serial8250_out_MCR(up, save_mcr); serial8250_clear_fifos(up); serial_in(up, UART_RX); if (up->capabilities & UART_CAP_UUE) serial_out(up, UART_IER, UART_IER_UUE); else serial_out(up, UART_IER, 0); out_lock: spin_unlock_irqrestore(&port->lock, flags); /* * Check if the device is a Fintek F81216A */ if (port->type == PORT_16550A && port->iotype == UPIO_PORT) fintek_8250_probe(up); if (up->capabilities != old_capabilities) { dev_warn(port->dev, "detected caps %08x should be %08x\n", old_capabilities, up->capabilities); } out: DEBUG_AUTOCONF("iir=%d ", scratch); DEBUG_AUTOCONF("type=%s\n", uart_config[port->type].name); } static void autoconfig_irq(struct uart_8250_port *up) { struct uart_port *port = &up->port; unsigned char save_mcr, save_ier; unsigned char save_ICP = 0; unsigned int ICP = 0; unsigned long irqs; int irq; if (port->flags & UPF_FOURPORT) { ICP = (port->iobase & 0xfe0) | 0x1f; save_ICP = inb_p(ICP); outb_p(0x80, ICP); inb_p(ICP); } if (uart_console(port)) console_lock(); /* forget possible initially masked and pending IRQ */ probe_irq_off(probe_irq_on()); save_mcr = serial8250_in_MCR(up); save_ier = serial_in(up, UART_IER); serial8250_out_MCR(up, UART_MCR_OUT1 | UART_MCR_OUT2); irqs = probe_irq_on(); serial8250_out_MCR(up, 0); udelay(10); if (port->flags & UPF_FOURPORT) { serial8250_out_MCR(up, UART_MCR_DTR | UART_MCR_RTS); } else { serial8250_out_MCR(up, UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2); } serial_out(up, UART_IER, 0x0f); /* enable all intrs */ serial_in(up, UART_LSR); serial_in(up, UART_RX); serial_in(up, UART_IIR); serial_in(up, UART_MSR); serial_out(up, UART_TX, 0xFF); udelay(20); irq = probe_irq_off(irqs); serial8250_out_MCR(up, save_mcr); serial_out(up, UART_IER, save_ier); if (port->flags & UPF_FOURPORT) outb_p(save_ICP, ICP); if (uart_console(port)) console_unlock(); port->irq = (irq > 0) ? irq : 0; } static void serial8250_stop_rx(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); serial8250_rpm_get(up); up->ier &= ~(UART_IER_RLSI | UART_IER_RDI); up->port.read_status_mask &= ~UART_LSR_DR; serial_port_out(port, UART_IER, up->ier); serial8250_rpm_put(up); } /** * serial8250_em485_stop_tx() - generic ->rs485_stop_tx() callback * @up: uart 8250 port * * Generic callback usable by 8250 uart drivers to stop rs485 transmission. */ void serial8250_em485_stop_tx(struct uart_8250_port *p) { unsigned char mcr = serial8250_in_MCR(p); if (p->port.rs485.flags & SER_RS485_RTS_AFTER_SEND) mcr |= UART_MCR_RTS; else mcr &= ~UART_MCR_RTS; serial8250_out_MCR(p, mcr); /* * Empty the RX FIFO, we are not interested in anything * received during the half-duplex transmission. * Enable previously disabled RX interrupts. */ if (!(p->port.rs485.flags & SER_RS485_RX_DURING_TX)) { serial8250_clear_and_reinit_fifos(p); p->ier |= UART_IER_RLSI | UART_IER_RDI; serial_port_out(&p->port, UART_IER, p->ier); } } EXPORT_SYMBOL_GPL(serial8250_em485_stop_tx); static enum hrtimer_restart serial8250_em485_handle_stop_tx(struct hrtimer *t) { struct uart_8250_em485 *em485; struct uart_8250_port *p; unsigned long flags; em485 = container_of(t, struct uart_8250_em485, stop_tx_timer); p = em485->port; serial8250_rpm_get(p); spin_lock_irqsave(&p->port.lock, flags); if (em485->active_timer == &em485->stop_tx_timer) { p->rs485_stop_tx(p); em485->active_timer = NULL; em485->tx_stopped = true; } spin_unlock_irqrestore(&p->port.lock, flags); serial8250_rpm_put(p); return HRTIMER_NORESTART; } static void start_hrtimer_ms(struct hrtimer *hrt, unsigned long msec) { long sec = msec / 1000; long nsec = (msec % 1000) * 1000000; ktime_t t = ktime_set(sec, nsec); hrtimer_start(hrt, t, HRTIMER_MODE_REL); } static void __stop_tx_rs485(struct uart_8250_port *p) { struct uart_8250_em485 *em485 = p->em485; /* * rs485_stop_tx() is going to set RTS according to config * AND flush RX FIFO if required. */ if (p->port.rs485.delay_rts_after_send > 0) { em485->active_timer = &em485->stop_tx_timer; start_hrtimer_ms(&em485->stop_tx_timer, p->port.rs485.delay_rts_after_send); } else { p->rs485_stop_tx(p); em485->active_timer = NULL; em485->tx_stopped = true; } } static inline void __do_stop_tx(struct uart_8250_port *p) { if (serial8250_clear_THRI(p)) serial8250_rpm_put_tx(p); } static inline void __stop_tx(struct uart_8250_port *p) { struct uart_8250_em485 *em485 = p->em485; if (em485) { unsigned char lsr = serial_in(p, UART_LSR); /* * To provide required timeing and allow FIFO transfer, * __stop_tx_rs485() must be called only when both FIFO and * shift register are empty. It is for device driver to enable * interrupt on TEMT. */ if ((lsr & BOTH_EMPTY) != BOTH_EMPTY) return; __stop_tx_rs485(p); } __do_stop_tx(p); } static void serial8250_stop_tx(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); serial8250_rpm_get(up); __stop_tx(up); /* * We really want to stop the transmitter from sending. */ if (port->type == PORT_16C950) { up->acr |= UART_ACR_TXDIS; serial_icr_write(up, UART_ACR, up->acr); } serial8250_rpm_put(up); } static inline void __start_tx(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); if (up->dma && !up->dma->tx_dma(up)) return; if (serial8250_set_THRI(up)) { if (up->bugs & UART_BUG_TXEN) { unsigned char lsr; lsr = serial_in(up, UART_LSR); up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS; if (lsr & UART_LSR_THRE) serial8250_tx_chars(up); } } /* * Re-enable the transmitter if we disabled it. */ if (port->type == PORT_16C950 && up->acr & UART_ACR_TXDIS) { up->acr &= ~UART_ACR_TXDIS; serial_icr_write(up, UART_ACR, up->acr); } } /** * serial8250_em485_start_tx() - generic ->rs485_start_tx() callback * @up: uart 8250 port * * Generic callback usable by 8250 uart drivers to start rs485 transmission. * Assumes that setting the RTS bit in the MCR register means RTS is high. * (Some chips use inverse semantics.) Further assumes that reception is * stoppable by disabling the UART_IER_RDI interrupt. (Some chips set the * UART_LSR_DR bit even when UART_IER_RDI is disabled, foiling this approach.) */ void serial8250_em485_start_tx(struct uart_8250_port *up) { unsigned char mcr = serial8250_in_MCR(up); if (!(up->port.rs485.flags & SER_RS485_RX_DURING_TX)) serial8250_stop_rx(&up->port); if (up->port.rs485.flags & SER_RS485_RTS_ON_SEND) mcr |= UART_MCR_RTS; else mcr &= ~UART_MCR_RTS; serial8250_out_MCR(up, mcr); } EXPORT_SYMBOL_GPL(serial8250_em485_start_tx); static inline void start_tx_rs485(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); struct uart_8250_em485 *em485 = up->em485; em485->active_timer = NULL; if (em485->tx_stopped) { em485->tx_stopped = false; up->rs485_start_tx(up); if (up->port.rs485.delay_rts_before_send > 0) { em485->active_timer = &em485->start_tx_timer; start_hrtimer_ms(&em485->start_tx_timer, up->port.rs485.delay_rts_before_send); return; } } __start_tx(port); } static enum hrtimer_restart serial8250_em485_handle_start_tx(struct hrtimer *t) { struct uart_8250_em485 *em485; struct uart_8250_port *p; unsigned long flags; em485 = container_of(t, struct uart_8250_em485, start_tx_timer); p = em485->port; spin_lock_irqsave(&p->port.lock, flags); if (em485->active_timer == &em485->start_tx_timer) { __start_tx(&p->port); em485->active_timer = NULL; } spin_unlock_irqrestore(&p->port.lock, flags); return HRTIMER_NORESTART; } static void serial8250_start_tx(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); struct uart_8250_em485 *em485 = up->em485; serial8250_rpm_get_tx(up); if (em485 && em485->active_timer == &em485->start_tx_timer) return; if (em485) start_tx_rs485(port); else __start_tx(port); } static void serial8250_throttle(struct uart_port *port) { port->throttle(port); } static void serial8250_unthrottle(struct uart_port *port) { port->unthrottle(port); } static void serial8250_disable_ms(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); /* no MSR capabilities */ if (up->bugs & UART_BUG_NOMSR) return; mctrl_gpio_disable_ms(up->gpios); up->ier &= ~UART_IER_MSI; serial_port_out(port, UART_IER, up->ier); } static void serial8250_enable_ms(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); /* no MSR capabilities */ if (up->bugs & UART_BUG_NOMSR) return; mctrl_gpio_enable_ms(up->gpios); up->ier |= UART_IER_MSI; serial8250_rpm_get(up); serial_port_out(port, UART_IER, up->ier); serial8250_rpm_put(up); } void serial8250_read_char(struct uart_8250_port *up, unsigned char lsr) { struct uart_port *port = &up->port; unsigned char ch; char flag = TTY_NORMAL; if (likely(lsr & UART_LSR_DR)) ch = serial_in(up, UART_RX); else /* * Intel 82571 has a Serial Over Lan device that will * set UART_LSR_BI without setting UART_LSR_DR when * it receives a break. To avoid reading from the * receive buffer without UART_LSR_DR bit set, we * just force the read character to be 0 */ ch = 0; port->icount.rx++; lsr |= up->lsr_saved_flags; up->lsr_saved_flags = 0; if (unlikely(lsr & UART_LSR_BRK_ERROR_BITS)) { if (lsr & UART_LSR_BI) { lsr &= ~(UART_LSR_FE | UART_LSR_PE); port->icount.brk++; /* * We do the SysRQ and SAK checking * here because otherwise the break * may get masked by ignore_status_mask * or read_status_mask. */ if (uart_handle_break(port)) return; } else if (lsr & UART_LSR_PE) port->icount.parity++; else if (lsr & UART_LSR_FE) port->icount.frame++; if (lsr & UART_LSR_OE) port->icount.overrun++; /* * Mask off conditions which should be ignored. */ lsr &= port->read_status_mask; if (lsr & UART_LSR_BI) { dev_dbg(port->dev, "handling break\n"); flag = TTY_BREAK; } else if (lsr & UART_LSR_PE) flag = TTY_PARITY; else if (lsr & UART_LSR_FE) flag = TTY_FRAME; } if (uart_prepare_sysrq_char(port, ch)) return; uart_insert_char(port, lsr, UART_LSR_OE, ch, flag); } EXPORT_SYMBOL_GPL(serial8250_read_char); /* * serial8250_rx_chars: processes according to the passed in LSR * value, and returns the remaining LSR bits not handled * by this Rx routine. */ unsigned char serial8250_rx_chars(struct uart_8250_port *up, unsigned char lsr) { struct uart_port *port = &up->port; int max_count = 256; do { serial8250_read_char(up, lsr); if (--max_count == 0) break; lsr = serial_in(up, UART_LSR); } while (lsr & (UART_LSR_DR | UART_LSR_BI)); tty_flip_buffer_push(&port->state->port); return lsr; } EXPORT_SYMBOL_GPL(serial8250_rx_chars); void serial8250_tx_chars(struct uart_8250_port *up) { struct uart_port *port = &up->port; struct circ_buf *xmit = &port->state->xmit; int count; if (port->x_char) { serial_out(up, UART_TX, port->x_char); port->icount.tx++; port->x_char = 0; return; } if (uart_tx_stopped(port)) { serial8250_stop_tx(port); return; } if (uart_circ_empty(xmit)) { __stop_tx(up); return; } count = up->tx_loadsz; do { serial_out(up, UART_TX, xmit->buf[xmit->tail]); xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); port->icount.tx++; if (uart_circ_empty(xmit)) break; if ((up->capabilities & UART_CAP_HFIFO) && (serial_in(up, UART_LSR) & BOTH_EMPTY) != BOTH_EMPTY) break; /* The BCM2835 MINI UART THRE bit is really a not-full bit. */ if ((up->capabilities & UART_CAP_MINI) && !(serial_in(up, UART_LSR) & UART_LSR_THRE)) break; } while (--count > 0); if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); /* * With RPM enabled, we have to wait until the FIFO is empty before the * HW can go idle. So we get here once again with empty FIFO and disable * the interrupt and RPM in __stop_tx() */ if (uart_circ_empty(xmit) && !(up->capabilities & UART_CAP_RPM)) __stop_tx(up); } EXPORT_SYMBOL_GPL(serial8250_tx_chars); /* Caller holds uart port lock */ unsigned int serial8250_modem_status(struct uart_8250_port *up) { struct uart_port *port = &up->port; unsigned int status = serial_in(up, UART_MSR); status |= up->msr_saved_flags; up->msr_saved_flags = 0; if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI && port->state != NULL) { if (status & UART_MSR_TERI) port->icount.rng++; if (status & UART_MSR_DDSR) port->icount.dsr++; if (status & UART_MSR_DDCD) uart_handle_dcd_change(port, status & UART_MSR_DCD); if (status & UART_MSR_DCTS) uart_handle_cts_change(port, status & UART_MSR_CTS); wake_up_interruptible(&port->state->port.delta_msr_wait); } return status; } EXPORT_SYMBOL_GPL(serial8250_modem_status); static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir) { switch (iir & 0x3f) { case UART_IIR_RX_TIMEOUT: serial8250_rx_dma_flush(up); /* fall-through */ case UART_IIR_RLSI: return true; } return up->dma->rx_dma(up); } /* * This handles the interrupt from one port. */ int serial8250_handle_irq(struct uart_port *port, unsigned int iir) { unsigned char status; unsigned long flags; struct uart_8250_port *up = up_to_u8250p(port); bool skip_rx = false; if (iir & UART_IIR_NO_INT) return 0; spin_lock_irqsave(&port->lock, flags); status = serial_port_in(port, UART_LSR); /* * If port is stopped and there are no error conditions in the * FIFO, then don't drain the FIFO, as this may lead to TTY buffer * overflow. Not servicing, RX FIFO would trigger auto HW flow * control when FIFO occupancy reaches preset threshold, thus * halting RX. This only works when auto HW flow control is * available. */ if (!(status & (UART_LSR_FIFOE | UART_LSR_BRK_ERROR_BITS)) && (port->status & (UPSTAT_AUTOCTS | UPSTAT_AUTORTS)) && !(port->read_status_mask & UART_LSR_DR)) skip_rx = true; if (status & (UART_LSR_DR | UART_LSR_BI) && !skip_rx) { if (!up->dma || handle_rx_dma(up, iir)) status = serial8250_rx_chars(up, status); } serial8250_modem_status(up); if ((!up->dma || up->dma->tx_err) && (status & UART_LSR_THRE) && (up->ier & UART_IER_THRI)) serial8250_tx_chars(up); uart_unlock_and_check_sysrq(port, flags); return 1; } EXPORT_SYMBOL_GPL(serial8250_handle_irq); static int serial8250_default_handle_irq(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); unsigned int iir; int ret; serial8250_rpm_get(up); iir = serial_port_in(port, UART_IIR); ret = serial8250_handle_irq(port, iir); serial8250_rpm_put(up); return ret; } /* * Newer 16550 compatible parts such as the SC16C650 & Altera 16550 Soft IP * have a programmable TX threshold that triggers the THRE interrupt in * the IIR register. In this case, the THRE interrupt indicates the FIFO * has space available. Load it up with tx_loadsz bytes. */ static int serial8250_tx_threshold_handle_irq(struct uart_port *port) { unsigned long flags; unsigned int iir = serial_port_in(port, UART_IIR); /* TX Threshold IRQ triggered so load up FIFO */ if ((iir & UART_IIR_ID) == UART_IIR_THRI) { struct uart_8250_port *up = up_to_u8250p(port); spin_lock_irqsave(&port->lock, flags); serial8250_tx_chars(up); spin_unlock_irqrestore(&port->lock, flags); } iir = serial_port_in(port, UART_IIR); return serial8250_handle_irq(port, iir); } static unsigned int serial8250_tx_empty(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); unsigned long flags; unsigned int lsr; serial8250_rpm_get(up); spin_lock_irqsave(&port->lock, flags); lsr = serial_port_in(port, UART_LSR); up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS; spin_unlock_irqrestore(&port->lock, flags); serial8250_rpm_put(up); return (lsr & BOTH_EMPTY) == BOTH_EMPTY ? TIOCSER_TEMT : 0; } unsigned int serial8250_do_get_mctrl(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); unsigned int status; unsigned int val; serial8250_rpm_get(up); status = serial8250_modem_status(up); serial8250_rpm_put(up); val = serial8250_MSR_to_TIOCM(status); if (up->gpios) return mctrl_gpio_get(up->gpios, &val); return val; } EXPORT_SYMBOL_GPL(serial8250_do_get_mctrl); static unsigned int serial8250_get_mctrl(struct uart_port *port) { if (port->get_mctrl) return port->get_mctrl(port); return serial8250_do_get_mctrl(port); } void serial8250_do_set_mctrl(struct uart_port *port, unsigned int mctrl) { struct uart_8250_port *up = up_to_u8250p(port); unsigned char mcr; if (port->rs485.flags & SER_RS485_ENABLED) { if (serial8250_in_MCR(up) & UART_MCR_RTS) mctrl |= TIOCM_RTS; else mctrl &= ~TIOCM_RTS; } mcr = serial8250_TIOCM_to_MCR(mctrl); mcr = (mcr & up->mcr_mask) | up->mcr_force | up->mcr; serial8250_out_MCR(up, mcr); } EXPORT_SYMBOL_GPL(serial8250_do_set_mctrl); static void serial8250_set_mctrl(struct uart_port *port, unsigned int mctrl) { if (port->set_mctrl) port->set_mctrl(port, mctrl); else serial8250_do_set_mctrl(port, mctrl); } static void serial8250_break_ctl(struct uart_port *port, int break_state) { struct uart_8250_port *up = up_to_u8250p(port); unsigned long flags; serial8250_rpm_get(up); spin_lock_irqsave(&port->lock, flags); if (break_state == -1) up->lcr |= UART_LCR_SBC; else up->lcr &= ~UART_LCR_SBC; serial_port_out(port, UART_LCR, up->lcr); spin_unlock_irqrestore(&port->lock, flags); serial8250_rpm_put(up); } /* * Wait for transmitter & holding register to empty */ static void wait_for_xmitr(struct uart_8250_port *up, int bits) { unsigned int status, tmout = 10000; /* Wait up to 10ms for the character(s) to be sent. */ for (;;) { status = serial_in(up, UART_LSR); up->lsr_saved_flags |= status & LSR_SAVE_FLAGS; if ((status & bits) == bits) break; if (--tmout == 0) break; udelay(1); touch_nmi_watchdog(); } /* Wait up to 1s for flow control if necessary */ if (up->port.flags & UPF_CONS_FLOW) { for (tmout = 1000000; tmout; tmout--) { unsigned int msr = serial_in(up, UART_MSR); up->msr_saved_flags |= msr & MSR_SAVE_FLAGS; if (msr & UART_MSR_CTS) break; udelay(1); touch_nmi_watchdog(); } } } #ifdef CONFIG_CONSOLE_POLL /* * Console polling routines for writing and reading from the uart while * in an interrupt or debug context. */ static int serial8250_get_poll_char(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); unsigned char lsr; int status; serial8250_rpm_get(up); lsr = serial_port_in(port, UART_LSR); if (!(lsr & UART_LSR_DR)) { status = NO_POLL_CHAR; goto out; } status = serial_port_in(port, UART_RX); out: serial8250_rpm_put(up); return status; } static void serial8250_put_poll_char(struct uart_port *port, unsigned char c) { unsigned int ier; struct uart_8250_port *up = up_to_u8250p(port); serial8250_rpm_get(up); /* * First save the IER then disable the interrupts */ ier = serial_port_in(port, UART_IER); if (up->capabilities & UART_CAP_UUE) serial_port_out(port, UART_IER, UART_IER_UUE); else serial_port_out(port, UART_IER, 0); wait_for_xmitr(up, BOTH_EMPTY); /* * Send the character out. */ serial_port_out(port, UART_TX, c); /* * Finally, wait for transmitter to become empty * and restore the IER */ wait_for_xmitr(up, BOTH_EMPTY); serial_port_out(port, UART_IER, ier); serial8250_rpm_put(up); } #endif /* CONFIG_CONSOLE_POLL */ int serial8250_do_startup(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); unsigned long flags; unsigned char lsr, iir; int retval; if (!port->fifosize) port->fifosize = uart_config[port->type].fifo_size; if (!up->tx_loadsz) up->tx_loadsz = uart_config[port->type].tx_loadsz; if (!up->capabilities) up->capabilities = uart_config[port->type].flags; up->mcr = 0; if (port->iotype != up->cur_iotype) set_io_from_upio(port); serial8250_rpm_get(up); if (port->type == PORT_16C950) { /* Wake up and initialize UART */ up->acr = 0; serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B); serial_port_out(port, UART_EFR, UART_EFR_ECB); serial_port_out(port, UART_IER, 0); serial_port_out(port, UART_LCR, 0); serial_icr_write(up, UART_CSR, 0); /* Reset the UART */ serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B); serial_port_out(port, UART_EFR, UART_EFR_ECB); serial_port_out(port, UART_LCR, 0); } if (port->type == PORT_DA830) { /* Reset the port */ serial_port_out(port, UART_IER, 0); serial_port_out(port, UART_DA830_PWREMU_MGMT, 0); mdelay(10); /* Enable Tx, Rx and free run mode */ serial_port_out(port, UART_DA830_PWREMU_MGMT, UART_DA830_PWREMU_MGMT_UTRST | UART_DA830_PWREMU_MGMT_URRST | UART_DA830_PWREMU_MGMT_FREE); } if (port->type == PORT_NPCM) { /* * Nuvoton calls the scratch register 'UART_TOR' (timeout * register). Enable it, and set TIOC (timeout interrupt * comparator) to be 0x20 for correct operation. */ serial_port_out(port, UART_NPCM_TOR, UART_NPCM_TOIE | 0x20); } #ifdef CONFIG_SERIAL_8250_RSA /* * If this is an RSA port, see if we can kick it up to the * higher speed clock. */ enable_rsa(up); #endif /* * Clear the FIFO buffers and disable them. * (they will be reenabled in set_termios()) */ serial8250_clear_fifos(up); /* * Clear the interrupt registers. */ serial_port_in(port, UART_LSR); serial_port_in(port, UART_RX); serial_port_in(port, UART_IIR); serial_port_in(port, UART_MSR); /* * At this point, there's no way the LSR could still be 0xff; * if it is, then bail out, because there's likely no UART * here. */ if (!(port->flags & UPF_BUGGY_UART) && (serial_port_in(port, UART_LSR) == 0xff)) { dev_info_ratelimited(port->dev, "LSR safety check engaged!\n"); retval = -ENODEV; goto out; } /* * For a XR16C850, we need to set the trigger levels */ if (port->type == PORT_16850) { unsigned char fctr; serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); fctr = serial_in(up, UART_FCTR) & ~(UART_FCTR_RX|UART_FCTR_TX); serial_port_out(port, UART_FCTR, fctr | UART_FCTR_TRGD | UART_FCTR_RX); serial_port_out(port, UART_TRG, UART_TRG_96); serial_port_out(port, UART_FCTR, fctr | UART_FCTR_TRGD | UART_FCTR_TX); serial_port_out(port, UART_TRG, UART_TRG_96); serial_port_out(port, UART_LCR, 0); } /* * For the Altera 16550 variants, set TX threshold trigger level. */ if (((port->type == PORT_ALTR_16550_F32) || (port->type == PORT_ALTR_16550_F64) || (port->type == PORT_ALTR_16550_F128)) && (port->fifosize > 1)) { /* Bounds checking of TX threshold (valid 0 to fifosize-2) */ if ((up->tx_loadsz < 2) || (up->tx_loadsz > port->fifosize)) { dev_err(port->dev, "TX FIFO Threshold errors, skipping\n"); } else { serial_port_out(port, UART_ALTR_AFR, UART_ALTR_EN_TXFIFO_LW); serial_port_out(port, UART_ALTR_TX_LOW, port->fifosize - up->tx_loadsz); port->handle_irq = serial8250_tx_threshold_handle_irq; } } /* Check if we need to have shared IRQs */ if (port->irq && (up->port.flags & UPF_SHARE_IRQ)) up->port.irqflags |= IRQF_SHARED; if (port->irq && !(up->port.flags & UPF_NO_THRE_TEST)) { unsigned char iir1; /* * Test for UARTs that do not reassert THRE when the * transmitter is idle and the interrupt has already * been cleared. Real 16550s should always reassert * this interrupt whenever the transmitter is idle and * the interrupt is enabled. Delays are necessary to * allow register changes to become visible. */ spin_lock_irqsave(&port->lock, flags); if (up->port.irqflags & IRQF_SHARED) disable_irq_nosync(port->irq); wait_for_xmitr(up, UART_LSR_THRE); serial_port_out_sync(port, UART_IER, UART_IER_THRI); udelay(1); /* allow THRE to set */ iir1 = serial_port_in(port, UART_IIR); serial_port_out(port, UART_IER, 0); serial_port_out_sync(port, UART_IER, UART_IER_THRI); udelay(1); /* allow a working UART time to re-assert THRE */ iir = serial_port_in(port, UART_IIR); serial_port_out(port, UART_IER, 0); if (port->irqflags & IRQF_SHARED) enable_irq(port->irq); spin_unlock_irqrestore(&port->lock, flags); /* * If the interrupt is not reasserted, or we otherwise * don't trust the iir, setup a timer to kick the UART * on a regular basis. */ if ((!(iir1 & UART_IIR_NO_INT) && (iir & UART_IIR_NO_INT)) || up->port.flags & UPF_BUG_THRE) { up->bugs |= UART_BUG_THRE; } } retval = up->ops->setup_irq(up); if (retval) goto out; /* * Now, initialize the UART */ serial_port_out(port, UART_LCR, UART_LCR_WLEN8); spin_lock_irqsave(&port->lock, flags); if (up->port.flags & UPF_FOURPORT) { if (!up->port.irq) up->port.mctrl |= TIOCM_OUT1; } else /* * Most PC uarts need OUT2 raised to enable interrupts. */ if (port->irq) up->port.mctrl |= TIOCM_OUT2; serial8250_set_mctrl(port, port->mctrl); /* * Serial over Lan (SoL) hack: * Intel 8257x Gigabit ethernet chips have a 16550 emulation, to be * used for Serial Over Lan. Those chips take a longer time than a * normal serial device to signalize that a transmission data was * queued. Due to that, the above test generally fails. One solution * would be to delay the reading of iir. However, this is not * reliable, since the timeout is variable. So, let's just don't * test if we receive TX irq. This way, we'll never enable * UART_BUG_TXEN. */ if (up->port.quirks & UPQ_NO_TXEN_TEST) goto dont_test_tx_en; /* * Do a quick test to see if we receive an interrupt when we enable * the TX irq. */ serial_port_out(port, UART_IER, UART_IER_THRI); lsr = serial_port_in(port, UART_LSR); iir = serial_port_in(port, UART_IIR); serial_port_out(port, UART_IER, 0); if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) { if (!(up->bugs & UART_BUG_TXEN)) { up->bugs |= UART_BUG_TXEN; dev_dbg(port->dev, "enabling bad tx status workarounds\n"); } } else { up->bugs &= ~UART_BUG_TXEN; } dont_test_tx_en: spin_unlock_irqrestore(&port->lock, flags); /* * Clear the interrupt registers again for luck, and clear the * saved flags to avoid getting false values from polling * routines or the previous session. */ serial_port_in(port, UART_LSR); serial_port_in(port, UART_RX); serial_port_in(port, UART_IIR); serial_port_in(port, UART_MSR); up->lsr_saved_flags = 0; up->msr_saved_flags = 0; /* * Request DMA channels for both RX and TX. */ if (up->dma) { const char *msg = NULL; if (uart_console(port)) msg = "forbid DMA for kernel console"; else if (serial8250_request_dma(up)) msg = "failed to request DMA"; if (msg) { dev_warn_ratelimited(port->dev, "%s\n", msg); up->dma = NULL; } } /* * Set the IER shadow for rx interrupts but defer actual interrupt * enable until after the FIFOs are enabled; otherwise, an already- * active sender can swamp the interrupt handler with "too much work". */ up->ier = UART_IER_RLSI | UART_IER_RDI; if (port->flags & UPF_FOURPORT) { unsigned int icp; /* * Enable interrupts on the AST Fourport board */ icp = (port->iobase & 0xfe0) | 0x01f; outb_p(0x80, icp); inb_p(icp); } retval = 0; out: serial8250_rpm_put(up); return retval; } EXPORT_SYMBOL_GPL(serial8250_do_startup); static int serial8250_startup(struct uart_port *port) { if (port->startup) return port->startup(port); return serial8250_do_startup(port); } void serial8250_do_shutdown(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); unsigned long flags; serial8250_rpm_get(up); /* * Disable interrupts from this port */ spin_lock_irqsave(&port->lock, flags); up->ier = 0; serial_port_out(port, UART_IER, 0); spin_unlock_irqrestore(&port->lock, flags); synchronize_irq(port->irq); if (up->dma) serial8250_release_dma(up); spin_lock_irqsave(&port->lock, flags); if (port->flags & UPF_FOURPORT) { /* reset interrupts on the AST Fourport board */ inb((port->iobase & 0xfe0) | 0x1f); port->mctrl |= TIOCM_OUT1; } else port->mctrl &= ~TIOCM_OUT2; serial8250_set_mctrl(port, port->mctrl); spin_unlock_irqrestore(&port->lock, flags); /* * Disable break condition and FIFOs */ serial_port_out(port, UART_LCR, serial_port_in(port, UART_LCR) & ~UART_LCR_SBC); serial8250_clear_fifos(up); #ifdef CONFIG_SERIAL_8250_RSA /* * Reset the RSA board back to 115kbps compat mode. */ disable_rsa(up); #endif /* * Read data port to reset things, and then unlink from * the IRQ chain. */ serial_port_in(port, UART_RX); serial8250_rpm_put(up); up->ops->release_irq(up); } EXPORT_SYMBOL_GPL(serial8250_do_shutdown); static void serial8250_shutdown(struct uart_port *port) { if (port->shutdown) port->shutdown(port); else serial8250_do_shutdown(port); } /* Nuvoton NPCM UARTs have a custom divisor calculation */ static unsigned int npcm_get_divisor(struct uart_8250_port *up, unsigned int baud) { struct uart_port *port = &up->port; return DIV_ROUND_CLOSEST(port->uartclk, 16 * baud + 2) - 2; } static unsigned int serial8250_do_get_divisor(struct uart_port *port, unsigned int baud, unsigned int *frac) { struct uart_8250_port *up = up_to_u8250p(port); unsigned int quot; /* * Handle magic divisors for baud rates above baud_base on * SMSC SuperIO chips. * */ if ((port->flags & UPF_MAGIC_MULTIPLIER) && baud == (port->uartclk/4)) quot = 0x8001; else if ((port->flags & UPF_MAGIC_MULTIPLIER) && baud == (port->uartclk/8)) quot = 0x8002; else if (up->port.type == PORT_NPCM) quot = npcm_get_divisor(up, baud); else quot = uart_get_divisor(port, baud); /* * Oxford Semi 952 rev B workaround */ if (up->bugs & UART_BUG_QUOT && (quot & 0xff) == 0) quot++; return quot; } static unsigned int serial8250_get_divisor(struct uart_port *port, unsigned int baud, unsigned int *frac) { if (port->get_divisor) return port->get_divisor(port, baud, frac); return serial8250_do_get_divisor(port, baud, frac); } static unsigned char serial8250_compute_lcr(struct uart_8250_port *up, tcflag_t c_cflag) { unsigned char cval; switch (c_cflag & CSIZE) { case CS5: cval = UART_LCR_WLEN5; break; case CS6: cval = UART_LCR_WLEN6; break; case CS7: cval = UART_LCR_WLEN7; break; default: case CS8: cval = UART_LCR_WLEN8; break; } if (c_cflag & CSTOPB) cval |= UART_LCR_STOP; if (c_cflag & PARENB) { cval |= UART_LCR_PARITY; if (up->bugs & UART_BUG_PARITY) up->fifo_bug = true; } if (!(c_cflag & PARODD)) cval |= UART_LCR_EPAR; #ifdef CMSPAR if (c_cflag & CMSPAR) cval |= UART_LCR_SPAR; #endif return cval; } void serial8250_do_set_divisor(struct uart_port *port, unsigned int baud, unsigned int quot, unsigned int quot_frac) { struct uart_8250_port *up = up_to_u8250p(port); /* Workaround to enable 115200 baud on OMAP1510 internal ports */ if (is_omap1510_8250(up)) { if (baud == 115200) { quot = 1; serial_port_out(port, UART_OMAP_OSC_12M_SEL, 1); } else serial_port_out(port, UART_OMAP_OSC_12M_SEL, 0); } /* * For NatSemi, switch to bank 2 not bank 1, to avoid resetting EXCR2, * otherwise just set DLAB */ if (up->capabilities & UART_NATSEMI) serial_port_out(port, UART_LCR, 0xe0); else serial_port_out(port, UART_LCR, up->lcr | UART_LCR_DLAB); serial_dl_write(up, quot); } EXPORT_SYMBOL_GPL(serial8250_do_set_divisor); static void serial8250_set_divisor(struct uart_port *port, unsigned int baud, unsigned int quot, unsigned int quot_frac) { if (port->set_divisor) port->set_divisor(port, baud, quot, quot_frac); else serial8250_do_set_divisor(port, baud, quot, quot_frac); } static unsigned int serial8250_get_baud_rate(struct uart_port *port, struct ktermios *termios, struct ktermios *old) { /* * Ask the core to calculate the divisor for us. * Allow 1% tolerance at the upper limit so uart clks marginally * slower than nominal still match standard baud rates without * causing transmission errors. */ return uart_get_baud_rate(port, termios, old, port->uartclk / 16 / UART_DIV_MAX, port->uartclk); } void serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old) { struct uart_8250_port *up = up_to_u8250p(port); unsigned char cval; unsigned long flags; unsigned int baud, quot, frac = 0; if (up->capabilities & UART_CAP_MINI) { termios->c_cflag &= ~(CSTOPB | PARENB | PARODD | CMSPAR); if ((termios->c_cflag & CSIZE) == CS5 || (termios->c_cflag & CSIZE) == CS6) termios->c_cflag = (termios->c_cflag & ~CSIZE) | CS7; } cval = serial8250_compute_lcr(up, termios->c_cflag); baud = serial8250_get_baud_rate(port, termios, old); quot = serial8250_get_divisor(port, baud, &frac); /* * Ok, we're now changing the port state. Do it with * interrupts disabled. */ serial8250_rpm_get(up); spin_lock_irqsave(&port->lock, flags); up->lcr = cval; /* Save computed LCR */ if (up->capabilities & UART_CAP_FIFO && port->fifosize > 1) { /* NOTE: If fifo_bug is not set, a user can set RX_trigger. */ if ((baud < 2400 && !up->dma) || up->fifo_bug) { up->fcr &= ~UART_FCR_TRIGGER_MASK; up->fcr |= UART_FCR_TRIGGER_1; } } /* * MCR-based auto flow control. When AFE is enabled, RTS will be * deasserted when the receive FIFO contains more characters than * the trigger, or the MCR RTS bit is cleared. */ if (up->capabilities & UART_CAP_AFE) { up->mcr &= ~UART_MCR_AFE; if (termios->c_cflag & CRTSCTS) up->mcr |= UART_MCR_AFE; } /* * Update the per-port timeout. */ uart_update_timeout(port, termios->c_cflag, baud); port->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR; if (termios->c_iflag & INPCK) port->read_status_mask |= UART_LSR_FE | UART_LSR_PE; if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) port->read_status_mask |= UART_LSR_BI; /* * Characteres to ignore */ port->ignore_status_mask = 0; if (termios->c_iflag & IGNPAR) port->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE; if (termios->c_iflag & IGNBRK) { port->ignore_status_mask |= UART_LSR_BI; /* * If we're ignoring parity and break indicators, * ignore overruns too (for real raw support). */ if (termios->c_iflag & IGNPAR) port->ignore_status_mask |= UART_LSR_OE; } /* * ignore all characters if CREAD is not set */ if ((termios->c_cflag & CREAD) == 0) port->ignore_status_mask |= UART_LSR_DR; /* * CTS flow control flag and modem status interrupts */ up->ier &= ~UART_IER_MSI; if (!(up->bugs & UART_BUG_NOMSR) && UART_ENABLE_MS(&up->port, termios->c_cflag)) up->ier |= UART_IER_MSI; if (up->capabilities & UART_CAP_UUE) up->ier |= UART_IER_UUE; if (up->capabilities & UART_CAP_RTOIE) up->ier |= UART_IER_RTOIE; serial_port_out(port, UART_IER, up->ier); if (up->capabilities & UART_CAP_EFR) { unsigned char efr = 0; /* * TI16C752/Startech hardware flow control. FIXME: * - TI16C752 requires control thresholds to be set. * - UART_MCR_RTS is ineffective if auto-RTS mode is enabled. */ if (termios->c_cflag & CRTSCTS) efr |= UART_EFR_CTS; serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B); if (port->flags & UPF_EXAR_EFR) serial_port_out(port, UART_XR_EFR, efr); else serial_port_out(port, UART_EFR, efr); } serial8250_set_divisor(port, baud, quot, frac); /* * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR * is written without DLAB set, this mode will be disabled. */ if (port->type == PORT_16750) serial_port_out(port, UART_FCR, up->fcr); serial_port_out(port, UART_LCR, up->lcr); /* reset DLAB */ if (port->type != PORT_16750) { /* emulated UARTs (Lucent Venus 167x) need two steps */ if (up->fcr & UART_FCR_ENABLE_FIFO) serial_port_out(port, UART_FCR, UART_FCR_ENABLE_FIFO); serial_port_out(port, UART_FCR, up->fcr); /* set fcr */ } serial8250_set_mctrl(port, port->mctrl); spin_unlock_irqrestore(&port->lock, flags); serial8250_rpm_put(up); /* Don't rewrite B0 */ if (tty_termios_baud_rate(termios)) tty_termios_encode_baud_rate(termios, baud, baud); } EXPORT_SYMBOL(serial8250_do_set_termios); static void serial8250_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old) { if (port->set_termios) port->set_termios(port, termios, old); else serial8250_do_set_termios(port, termios, old); } void serial8250_do_set_ldisc(struct uart_port *port, struct ktermios *termios) { if (termios->c_line == N_PPS) { port->flags |= UPF_HARDPPS_CD; spin_lock_irq(&port->lock); serial8250_enable_ms(port); spin_unlock_irq(&port->lock); } else { port->flags &= ~UPF_HARDPPS_CD; if (!UART_ENABLE_MS(port, termios->c_cflag)) { spin_lock_irq(&port->lock); serial8250_disable_ms(port); spin_unlock_irq(&port->lock); } } } EXPORT_SYMBOL_GPL(serial8250_do_set_ldisc); static void serial8250_set_ldisc(struct uart_port *port, struct ktermios *termios) { if (port->set_ldisc) port->set_ldisc(port, termios); else serial8250_do_set_ldisc(port, termios); } void serial8250_do_pm(struct uart_port *port, unsigned int state, unsigned int oldstate) { struct uart_8250_port *p = up_to_u8250p(port); serial8250_set_sleep(p, state != 0); } EXPORT_SYMBOL(serial8250_do_pm); static void serial8250_pm(struct uart_port *port, unsigned int state, unsigned int oldstate) { if (port->pm) port->pm(port, state, oldstate); else serial8250_do_pm(port, state, oldstate); } static unsigned int serial8250_port_size(struct uart_8250_port *pt) { if (pt->port.mapsize) return pt->port.mapsize; if (pt->port.iotype == UPIO_AU) { if (pt->port.type == PORT_RT2880) return 0x100; return 0x1000; } if (is_omap1_8250(pt)) return 0x16 << pt->port.regshift; return 8 << pt->port.regshift; } /* * Resource handling. */ static int serial8250_request_std_resource(struct uart_8250_port *up) { unsigned int size = serial8250_port_size(up); struct uart_port *port = &up->port; int ret = 0; switch (port->iotype) { case UPIO_AU: case UPIO_TSI: case UPIO_MEM32: case UPIO_MEM32BE: case UPIO_MEM16: case UPIO_MEM: if (!port->mapbase) break; if (!request_mem_region(port->mapbase, size, "serial")) { ret = -EBUSY; break; } if (port->flags & UPF_IOREMAP) { port->membase = ioremap(port->mapbase, size); if (!port->membase) { release_mem_region(port->mapbase, size); ret = -ENOMEM; } } break; case UPIO_HUB6: case UPIO_PORT: if (!request_region(port->iobase, size, "serial")) ret = -EBUSY; break; } return ret; } static void serial8250_release_std_resource(struct uart_8250_port *up) { unsigned int size = serial8250_port_size(up); struct uart_port *port = &up->port; switch (port->iotype) { case UPIO_AU: case UPIO_TSI: case UPIO_MEM32: case UPIO_MEM32BE: case UPIO_MEM16: case UPIO_MEM: if (!port->mapbase) break; if (port->flags & UPF_IOREMAP) { iounmap(port->membase); port->membase = NULL; } release_mem_region(port->mapbase, size); break; case UPIO_HUB6: case UPIO_PORT: release_region(port->iobase, size); break; } } static void serial8250_release_port(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); serial8250_release_std_resource(up); } static int serial8250_request_port(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); return serial8250_request_std_resource(up); } static int fcr_get_rxtrig_bytes(struct uart_8250_port *up) { const struct serial8250_config *conf_type = &uart_config[up->port.type]; unsigned char bytes; bytes = conf_type->rxtrig_bytes[UART_FCR_R_TRIG_BITS(up->fcr)]; return bytes ? bytes : -EOPNOTSUPP; } static int bytes_to_fcr_rxtrig(struct uart_8250_port *up, unsigned char bytes) { const struct serial8250_config *conf_type = &uart_config[up->port.type]; int i; if (!conf_type->rxtrig_bytes[UART_FCR_R_TRIG_BITS(UART_FCR_R_TRIG_00)]) return -EOPNOTSUPP; for (i = 1; i < UART_FCR_R_TRIG_MAX_STATE; i++) { if (bytes < conf_type->rxtrig_bytes[i]) /* Use the nearest lower value */ return (--i) << UART_FCR_R_TRIG_SHIFT; } return UART_FCR_R_TRIG_11; } static int do_get_rxtrig(struct tty_port *port) { struct uart_state *state = container_of(port, struct uart_state, port); struct uart_port *uport = state->uart_port; struct uart_8250_port *up = up_to_u8250p(uport); if (!(up->capabilities & UART_CAP_FIFO) || uport->fifosize <= 1) return -EINVAL; return fcr_get_rxtrig_bytes(up); } static int do_serial8250_get_rxtrig(struct tty_port *port) { int rxtrig_bytes; mutex_lock(&port->mutex); rxtrig_bytes = do_get_rxtrig(port); mutex_unlock(&port->mutex); return rxtrig_bytes; } static ssize_t rx_trig_bytes_show(struct device *dev, struct device_attribute *attr, char *buf) { struct tty_port *port = dev_get_drvdata(dev); int rxtrig_bytes; rxtrig_bytes = do_serial8250_get_rxtrig(port); if (rxtrig_bytes < 0) return rxtrig_bytes; return snprintf(buf, PAGE_SIZE, "%d\n", rxtrig_bytes); } static int do_set_rxtrig(struct tty_port *port, unsigned char bytes) { struct uart_state *state = container_of(port, struct uart_state, port); struct uart_port *uport = state->uart_port; struct uart_8250_port *up = up_to_u8250p(uport); int rxtrig; if (!(up->capabilities & UART_CAP_FIFO) || uport->fifosize <= 1 || up->fifo_bug) return -EINVAL; rxtrig = bytes_to_fcr_rxtrig(up, bytes); if (rxtrig < 0) return rxtrig; serial8250_clear_fifos(up); up->fcr &= ~UART_FCR_TRIGGER_MASK; up->fcr |= (unsigned char)rxtrig; serial_out(up, UART_FCR, up->fcr); return 0; } static int do_serial8250_set_rxtrig(struct tty_port *port, unsigned char bytes) { int ret; mutex_lock(&port->mutex); ret = do_set_rxtrig(port, bytes); mutex_unlock(&port->mutex); return ret; } static ssize_t rx_trig_bytes_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct tty_port *port = dev_get_drvdata(dev); unsigned char bytes; int ret; if (!count) return -EINVAL; ret = kstrtou8(buf, 10, &bytes); if (ret < 0) return ret; ret = do_serial8250_set_rxtrig(port, bytes); if (ret < 0) return ret; return count; } static DEVICE_ATTR_RW(rx_trig_bytes); static struct attribute *serial8250_dev_attrs[] = { &dev_attr_rx_trig_bytes.attr, NULL }; static struct attribute_group serial8250_dev_attr_group = { .attrs = serial8250_dev_attrs, }; static void register_dev_spec_attr_grp(struct uart_8250_port *up) { const struct serial8250_config *conf_type = &uart_config[up->port.type]; if (conf_type->rxtrig_bytes[0]) up->port.attr_group = &serial8250_dev_attr_group; } static void serial8250_config_port(struct uart_port *port, int flags) { struct uart_8250_port *up = up_to_u8250p(port); int ret; /* * Find the region that we can probe for. This in turn * tells us whether we can probe for the type of port. */ ret = serial8250_request_std_resource(up); if (ret < 0) return; if (port->iotype != up->cur_iotype) set_io_from_upio(port); if (flags & UART_CONFIG_TYPE) autoconfig(up); if (port->rs485.flags & SER_RS485_ENABLED) port->rs485_config(port, &port->rs485); /* if access method is AU, it is a 16550 with a quirk */ if (port->type == PORT_16550A && port->iotype == UPIO_AU) up->bugs |= UART_BUG_NOMSR; /* HW bugs may trigger IRQ while IIR == NO_INT */ if (port->type == PORT_TEGRA) up->bugs |= UART_BUG_NOMSR; if (port->type != PORT_UNKNOWN && flags & UART_CONFIG_IRQ) autoconfig_irq(up); if (port->type == PORT_UNKNOWN) serial8250_release_std_resource(up); register_dev_spec_attr_grp(up); up->fcr = uart_config[up->port.type].fcr; } static int serial8250_verify_port(struct uart_port *port, struct serial_struct *ser) { if (ser->irq >= nr_irqs || ser->irq < 0 || ser->baud_base < 9600 || ser->type < PORT_UNKNOWN || ser->type >= ARRAY_SIZE(uart_config) || ser->type == PORT_CIRRUS || ser->type == PORT_STARTECH) return -EINVAL; return 0; } static const char *serial8250_type(struct uart_port *port) { int type = port->type; if (type >= ARRAY_SIZE(uart_config)) type = 0; return uart_config[type].name; } static const struct uart_ops serial8250_pops = { .tx_empty = serial8250_tx_empty, .set_mctrl = serial8250_set_mctrl, .get_mctrl = serial8250_get_mctrl, .stop_tx = serial8250_stop_tx, .start_tx = serial8250_start_tx, .throttle = serial8250_throttle, .unthrottle = serial8250_unthrottle, .stop_rx = serial8250_stop_rx, .enable_ms = serial8250_enable_ms, .break_ctl = serial8250_break_ctl, .startup = serial8250_startup, .shutdown = serial8250_shutdown, .set_termios = serial8250_set_termios, .set_ldisc = serial8250_set_ldisc, .pm = serial8250_pm, .type = serial8250_type, .release_port = serial8250_release_port, .request_port = serial8250_request_port, .config_port = serial8250_config_port, .verify_port = serial8250_verify_port, #ifdef CONFIG_CONSOLE_POLL .poll_get_char = serial8250_get_poll_char, .poll_put_char = serial8250_put_poll_char, #endif }; void serial8250_init_port(struct uart_8250_port *up) { struct uart_port *port = &up->port; spin_lock_init(&port->lock); port->ops = &serial8250_pops; port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE); up->cur_iotype = 0xFF; } EXPORT_SYMBOL_GPL(serial8250_init_port); void serial8250_set_defaults(struct uart_8250_port *up) { struct uart_port *port = &up->port; if (up->port.flags & UPF_FIXED_TYPE) { unsigned int type = up->port.type; if (!up->port.fifosize) up->port.fifosize = uart_config[type].fifo_size; if (!up->tx_loadsz) up->tx_loadsz = uart_config[type].tx_loadsz; if (!up->capabilities) up->capabilities = uart_config[type].flags; } set_io_from_upio(port); /* default dma handlers */ if (up->dma) { if (!up->dma->tx_dma) up->dma->tx_dma = serial8250_tx_dma; if (!up->dma->rx_dma) up->dma->rx_dma = serial8250_rx_dma; } } EXPORT_SYMBOL_GPL(serial8250_set_defaults); #ifdef CONFIG_SERIAL_8250_CONSOLE static void serial8250_console_putchar(struct uart_port *port, int ch) { struct uart_8250_port *up = up_to_u8250p(port); wait_for_xmitr(up, UART_LSR_THRE); serial_port_out(port, UART_TX, ch); } /* * Restore serial console when h/w power-off detected */ static void serial8250_console_restore(struct uart_8250_port *up) { struct uart_port *port = &up->port; struct ktermios termios; unsigned int baud, quot, frac = 0; termios.c_cflag = port->cons->cflag; if (port->state->port.tty && termios.c_cflag == 0) termios.c_cflag = port->state->port.tty->termios.c_cflag; baud = serial8250_get_baud_rate(port, &termios, NULL); quot = serial8250_get_divisor(port, baud, &frac); serial8250_set_divisor(port, baud, quot, frac); serial_port_out(port, UART_LCR, up->lcr); serial8250_out_MCR(up, UART_MCR_DTR | UART_MCR_RTS); } /* * Print a string to the serial port trying not to disturb * any possible real use of the port... * * The console_lock must be held when we get here. * * Doing runtime PM is really a bad idea for the kernel console. * Thus, we assume the function is called when device is powered up. */ void serial8250_console_write(struct uart_8250_port *up, const char *s, unsigned int count) { struct uart_8250_em485 *em485 = up->em485; struct uart_port *port = &up->port; unsigned long flags; unsigned int ier; int locked = 1; touch_nmi_watchdog(); if (oops_in_progress) locked = spin_trylock_irqsave(&port->lock, flags); else spin_lock_irqsave(&port->lock, flags); /* * First save the IER then disable the interrupts */ ier = serial_port_in(port, UART_IER); if (up->capabilities & UART_CAP_UUE) serial_port_out(port, UART_IER, UART_IER_UUE); else serial_port_out(port, UART_IER, 0); /* check scratch reg to see if port powered off during system sleep */ if (up->canary && (up->canary != serial_port_in(port, UART_SCR))) { serial8250_console_restore(up); up->canary = 0; } if (em485) { if (em485->tx_stopped) up->rs485_start_tx(up); mdelay(port->rs485.delay_rts_before_send); } uart_console_write(port, s, count, serial8250_console_putchar); /* * Finally, wait for transmitter to become empty * and restore the IER */ wait_for_xmitr(up, BOTH_EMPTY); if (em485) { mdelay(port->rs485.delay_rts_after_send); if (em485->tx_stopped) up->rs485_stop_tx(up); } serial_port_out(port, UART_IER, ier); /* * The receive handling will happen properly because the * receive ready bit will still be set; it is not cleared * on read. However, modem control will not, we must * call it if we have saved something in the saved flags * while processing with interrupts off. */ if (up->msr_saved_flags) serial8250_modem_status(up); if (locked) spin_unlock_irqrestore(&port->lock, flags); } static unsigned int probe_baud(struct uart_port *port) { unsigned char lcr, dll, dlm; unsigned int quot; lcr = serial_port_in(port, UART_LCR); serial_port_out(port, UART_LCR, lcr | UART_LCR_DLAB); dll = serial_port_in(port, UART_DLL); dlm = serial_port_in(port, UART_DLM); serial_port_out(port, UART_LCR, lcr); quot = (dlm << 8) | dll; return (port->uartclk / 16) / quot; } int serial8250_console_setup(struct uart_port *port, char *options, bool probe) { int baud = 9600; int bits = 8; int parity = 'n'; int flow = 'n'; int ret; if (!port->iobase && !port->membase) return -ENODEV; if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); else if (probe) baud = probe_baud(port); ret = uart_set_options(port, port->cons, baud, parity, bits, flow); if (ret) return ret; if (port->dev) pm_runtime_get_sync(port->dev); return 0; } int serial8250_console_exit(struct uart_port *port) { if (port->dev) pm_runtime_put_sync(port->dev); return 0; } #endif /* CONFIG_SERIAL_8250_CONSOLE */ MODULE_LICENSE("GPL");
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