| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Laxman Dewangan | 5693 | 90.11% | 1 | 3.45% |
| Jon Hunter | 374 | 5.92% | 8 | 27.59% |
| Stephen Warren | 79 | 1.25% | 2 | 6.90% |
| Shardar Shariff Md | 55 | 0.87% | 2 | 6.90% |
| Peter Hurley | 41 | 0.65% | 1 | 3.45% |
| Jiri Slaby | 28 | 0.44% | 1 | 3.45% |
| Sachin Kamat | 11 | 0.17% | 1 | 3.45% |
| Pradeep Goudagunta | 11 | 0.17% | 2 | 6.90% |
| Thierry Reding | 8 | 0.13% | 1 | 3.45% |
| Marcel Ziswiler | 5 | 0.08% | 1 | 3.45% |
| Jingoo Han | 3 | 0.05% | 1 | 3.45% |
| Johan Hovold | 3 | 0.05% | 1 | 3.45% |
| Greg Kroah-Hartman | 2 | 0.03% | 2 | 6.90% |
| Bhumika Goyal | 1 | 0.02% | 1 | 3.45% |
| Michael Opdenacker | 1 | 0.02% | 1 | 3.45% |
| Fabian Frederick | 1 | 0.02% | 1 | 3.45% |
| Masanari Iida | 1 | 0.02% | 1 | 3.45% |
| Philipp Zabel | 1 | 0.02% | 1 | 3.45% |
| Total | 6318 | 29 |
// SPDX-License-Identifier: GPL-2.0 /* * serial_tegra.c * * High-speed serial driver for NVIDIA Tegra SoCs * * Copyright (c) 2012-2013, NVIDIA CORPORATION. All rights reserved. * * Author: Laxman Dewangan <ldewangan@nvidia.com> */ #include <linux/clk.h> #include <linux/debugfs.h> #include <linux/delay.h> #include <linux/dmaengine.h> #include <linux/dma-mapping.h> #include <linux/dmapool.h> #include <linux/err.h> #include <linux/io.h> #include <linux/irq.h> #include <linux/module.h> #include <linux/of.h> #include <linux/of_device.h> #include <linux/pagemap.h> #include <linux/platform_device.h> #include <linux/reset.h> #include <linux/serial.h> #include <linux/serial_8250.h> #include <linux/serial_core.h> #include <linux/serial_reg.h> #include <linux/slab.h> #include <linux/string.h> #include <linux/termios.h> #include <linux/tty.h> #include <linux/tty_flip.h> #define TEGRA_UART_TYPE "TEGRA_UART" #define TX_EMPTY_STATUS (UART_LSR_TEMT | UART_LSR_THRE) #define BYTES_TO_ALIGN(x) ((unsigned long)(x) & 0x3) #define TEGRA_UART_RX_DMA_BUFFER_SIZE 4096 #define TEGRA_UART_LSR_TXFIFO_FULL 0x100 #define TEGRA_UART_IER_EORD 0x20 #define TEGRA_UART_MCR_RTS_EN 0x40 #define TEGRA_UART_MCR_CTS_EN 0x20 #define TEGRA_UART_LSR_ANY (UART_LSR_OE | UART_LSR_BI | \ UART_LSR_PE | UART_LSR_FE) #define TEGRA_UART_IRDA_CSR 0x08 #define TEGRA_UART_SIR_ENABLED 0x80 #define TEGRA_UART_TX_PIO 1 #define TEGRA_UART_TX_DMA 2 #define TEGRA_UART_MIN_DMA 16 #define TEGRA_UART_FIFO_SIZE 32 /* * Tx fifo trigger level setting in tegra uart is in * reverse way then conventional uart. */ #define TEGRA_UART_TX_TRIG_16B 0x00 #define TEGRA_UART_TX_TRIG_8B 0x10 #define TEGRA_UART_TX_TRIG_4B 0x20 #define TEGRA_UART_TX_TRIG_1B 0x30 #define TEGRA_UART_MAXIMUM 5 /* Default UART setting when started: 115200 no parity, stop, 8 data bits */ #define TEGRA_UART_DEFAULT_BAUD 115200 #define TEGRA_UART_DEFAULT_LSR UART_LCR_WLEN8 /* Tx transfer mode */ #define TEGRA_TX_PIO 1 #define TEGRA_TX_DMA 2 /** * tegra_uart_chip_data: SOC specific data. * * @tx_fifo_full_status: Status flag available for checking tx fifo full. * @allow_txfifo_reset_fifo_mode: allow_tx fifo reset with fifo mode or not. * Tegra30 does not allow this. * @support_clk_src_div: Clock source support the clock divider. */ struct tegra_uart_chip_data { bool tx_fifo_full_status; bool allow_txfifo_reset_fifo_mode; bool support_clk_src_div; }; struct tegra_uart_port { struct uart_port uport; const struct tegra_uart_chip_data *cdata; struct clk *uart_clk; struct reset_control *rst; unsigned int current_baud; /* Register shadow */ unsigned long fcr_shadow; unsigned long mcr_shadow; unsigned long lcr_shadow; unsigned long ier_shadow; bool rts_active; int tx_in_progress; unsigned int tx_bytes; bool enable_modem_interrupt; bool rx_timeout; int rx_in_progress; int symb_bit; struct dma_chan *rx_dma_chan; struct dma_chan *tx_dma_chan; dma_addr_t rx_dma_buf_phys; dma_addr_t tx_dma_buf_phys; unsigned char *rx_dma_buf_virt; unsigned char *tx_dma_buf_virt; struct dma_async_tx_descriptor *tx_dma_desc; struct dma_async_tx_descriptor *rx_dma_desc; dma_cookie_t tx_cookie; dma_cookie_t rx_cookie; unsigned int tx_bytes_requested; unsigned int rx_bytes_requested; }; static void tegra_uart_start_next_tx(struct tegra_uart_port *tup); static int tegra_uart_start_rx_dma(struct tegra_uart_port *tup); static inline unsigned long tegra_uart_read(struct tegra_uart_port *tup, unsigned long reg) { return readl(tup->uport.membase + (reg << tup->uport.regshift)); } static inline void tegra_uart_write(struct tegra_uart_port *tup, unsigned val, unsigned long reg) { writel(val, tup->uport.membase + (reg << tup->uport.regshift)); } static inline struct tegra_uart_port *to_tegra_uport(struct uart_port *u) { return container_of(u, struct tegra_uart_port, uport); } static unsigned int tegra_uart_get_mctrl(struct uart_port *u) { struct tegra_uart_port *tup = to_tegra_uport(u); /* * RI - Ring detector is active * CD/DCD/CAR - Carrier detect is always active. For some reason * linux has different names for carrier detect. * DSR - Data Set ready is active as the hardware doesn't support it. * Don't know if the linux support this yet? * CTS - Clear to send. Always set to active, as the hardware handles * CTS automatically. */ if (tup->enable_modem_interrupt) return TIOCM_RI | TIOCM_CD | TIOCM_DSR | TIOCM_CTS; return TIOCM_CTS; } static void set_rts(struct tegra_uart_port *tup, bool active) { unsigned long mcr; mcr = tup->mcr_shadow; if (active) mcr |= TEGRA_UART_MCR_RTS_EN; else mcr &= ~TEGRA_UART_MCR_RTS_EN; if (mcr != tup->mcr_shadow) { tegra_uart_write(tup, mcr, UART_MCR); tup->mcr_shadow = mcr; } } static void set_dtr(struct tegra_uart_port *tup, bool active) { unsigned long mcr; mcr = tup->mcr_shadow; if (active) mcr |= UART_MCR_DTR; else mcr &= ~UART_MCR_DTR; if (mcr != tup->mcr_shadow) { tegra_uart_write(tup, mcr, UART_MCR); tup->mcr_shadow = mcr; } } static void tegra_uart_set_mctrl(struct uart_port *u, unsigned int mctrl) { struct tegra_uart_port *tup = to_tegra_uport(u); int dtr_enable; tup->rts_active = !!(mctrl & TIOCM_RTS); set_rts(tup, tup->rts_active); dtr_enable = !!(mctrl & TIOCM_DTR); set_dtr(tup, dtr_enable); } static void tegra_uart_break_ctl(struct uart_port *u, int break_ctl) { struct tegra_uart_port *tup = to_tegra_uport(u); unsigned long lcr; lcr = tup->lcr_shadow; if (break_ctl) lcr |= UART_LCR_SBC; else lcr &= ~UART_LCR_SBC; tegra_uart_write(tup, lcr, UART_LCR); tup->lcr_shadow = lcr; } /** * tegra_uart_wait_cycle_time: Wait for N UART clock periods * * @tup: Tegra serial port data structure. * @cycles: Number of clock periods to wait. * * Tegra UARTs are clocked at 16X the baud/bit rate and hence the UART * clock speed is 16X the current baud rate. */ static void tegra_uart_wait_cycle_time(struct tegra_uart_port *tup, unsigned int cycles) { if (tup->current_baud) udelay(DIV_ROUND_UP(cycles * 1000000, tup->current_baud * 16)); } /* Wait for a symbol-time. */ static void tegra_uart_wait_sym_time(struct tegra_uart_port *tup, unsigned int syms) { if (tup->current_baud) udelay(DIV_ROUND_UP(syms * tup->symb_bit * 1000000, tup->current_baud)); } static void tegra_uart_fifo_reset(struct tegra_uart_port *tup, u8 fcr_bits) { unsigned long fcr = tup->fcr_shadow; if (tup->cdata->allow_txfifo_reset_fifo_mode) { fcr |= fcr_bits & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT); tegra_uart_write(tup, fcr, UART_FCR); } else { fcr &= ~UART_FCR_ENABLE_FIFO; tegra_uart_write(tup, fcr, UART_FCR); udelay(60); fcr |= fcr_bits & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT); tegra_uart_write(tup, fcr, UART_FCR); fcr |= UART_FCR_ENABLE_FIFO; tegra_uart_write(tup, fcr, UART_FCR); } /* Dummy read to ensure the write is posted */ tegra_uart_read(tup, UART_SCR); /* * For all tegra devices (up to t210), there is a hardware issue that * requires software to wait for 32 UART clock periods for the flush * to propagate, otherwise data could be lost. */ tegra_uart_wait_cycle_time(tup, 32); } static int tegra_set_baudrate(struct tegra_uart_port *tup, unsigned int baud) { unsigned long rate; unsigned int divisor; unsigned long lcr; int ret; if (tup->current_baud == baud) return 0; if (tup->cdata->support_clk_src_div) { rate = baud * 16; ret = clk_set_rate(tup->uart_clk, rate); if (ret < 0) { dev_err(tup->uport.dev, "clk_set_rate() failed for rate %lu\n", rate); return ret; } divisor = 1; } else { rate = clk_get_rate(tup->uart_clk); divisor = DIV_ROUND_CLOSEST(rate, baud * 16); } lcr = tup->lcr_shadow; lcr |= UART_LCR_DLAB; tegra_uart_write(tup, lcr, UART_LCR); tegra_uart_write(tup, divisor & 0xFF, UART_TX); tegra_uart_write(tup, ((divisor >> 8) & 0xFF), UART_IER); lcr &= ~UART_LCR_DLAB; tegra_uart_write(tup, lcr, UART_LCR); /* Dummy read to ensure the write is posted */ tegra_uart_read(tup, UART_SCR); tup->current_baud = baud; /* wait two character intervals at new rate */ tegra_uart_wait_sym_time(tup, 2); return 0; } static char tegra_uart_decode_rx_error(struct tegra_uart_port *tup, unsigned long lsr) { char flag = TTY_NORMAL; if (unlikely(lsr & TEGRA_UART_LSR_ANY)) { if (lsr & UART_LSR_OE) { /* Overrrun error */ flag = TTY_OVERRUN; tup->uport.icount.overrun++; dev_err(tup->uport.dev, "Got overrun errors\n"); } else if (lsr & UART_LSR_PE) { /* Parity error */ flag = TTY_PARITY; tup->uport.icount.parity++; dev_err(tup->uport.dev, "Got Parity errors\n"); } else if (lsr & UART_LSR_FE) { flag = TTY_FRAME; tup->uport.icount.frame++; dev_err(tup->uport.dev, "Got frame errors\n"); } else if (lsr & UART_LSR_BI) { dev_err(tup->uport.dev, "Got Break\n"); tup->uport.icount.brk++; /* If FIFO read error without any data, reset Rx FIFO */ if (!(lsr & UART_LSR_DR) && (lsr & UART_LSR_FIFOE)) tegra_uart_fifo_reset(tup, UART_FCR_CLEAR_RCVR); } } return flag; } static int tegra_uart_request_port(struct uart_port *u) { return 0; } static void tegra_uart_release_port(struct uart_port *u) { /* Nothing to do here */ } static void tegra_uart_fill_tx_fifo(struct tegra_uart_port *tup, int max_bytes) { struct circ_buf *xmit = &tup->uport.state->xmit; int i; for (i = 0; i < max_bytes; i++) { BUG_ON(uart_circ_empty(xmit)); if (tup->cdata->tx_fifo_full_status) { unsigned long lsr = tegra_uart_read(tup, UART_LSR); if ((lsr & TEGRA_UART_LSR_TXFIFO_FULL)) break; } tegra_uart_write(tup, xmit->buf[xmit->tail], UART_TX); xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); tup->uport.icount.tx++; } } static void tegra_uart_start_pio_tx(struct tegra_uart_port *tup, unsigned int bytes) { if (bytes > TEGRA_UART_MIN_DMA) bytes = TEGRA_UART_MIN_DMA; tup->tx_in_progress = TEGRA_UART_TX_PIO; tup->tx_bytes = bytes; tup->ier_shadow |= UART_IER_THRI; tegra_uart_write(tup, tup->ier_shadow, UART_IER); } static void tegra_uart_tx_dma_complete(void *args) { struct tegra_uart_port *tup = args; struct circ_buf *xmit = &tup->uport.state->xmit; struct dma_tx_state state; unsigned long flags; unsigned int count; dmaengine_tx_status(tup->tx_dma_chan, tup->tx_cookie, &state); count = tup->tx_bytes_requested - state.residue; async_tx_ack(tup->tx_dma_desc); spin_lock_irqsave(&tup->uport.lock, flags); xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1); tup->tx_in_progress = 0; if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(&tup->uport); tegra_uart_start_next_tx(tup); spin_unlock_irqrestore(&tup->uport.lock, flags); } static int tegra_uart_start_tx_dma(struct tegra_uart_port *tup, unsigned long count) { struct circ_buf *xmit = &tup->uport.state->xmit; dma_addr_t tx_phys_addr; dma_sync_single_for_device(tup->uport.dev, tup->tx_dma_buf_phys, UART_XMIT_SIZE, DMA_TO_DEVICE); tup->tx_bytes = count & ~(0xF); tx_phys_addr = tup->tx_dma_buf_phys + xmit->tail; tup->tx_dma_desc = dmaengine_prep_slave_single(tup->tx_dma_chan, tx_phys_addr, tup->tx_bytes, DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT); if (!tup->tx_dma_desc) { dev_err(tup->uport.dev, "Not able to get desc for Tx\n"); return -EIO; } tup->tx_dma_desc->callback = tegra_uart_tx_dma_complete; tup->tx_dma_desc->callback_param = tup; tup->tx_in_progress = TEGRA_UART_TX_DMA; tup->tx_bytes_requested = tup->tx_bytes; tup->tx_cookie = dmaengine_submit(tup->tx_dma_desc); dma_async_issue_pending(tup->tx_dma_chan); return 0; } static void tegra_uart_start_next_tx(struct tegra_uart_port *tup) { unsigned long tail; unsigned long count; struct circ_buf *xmit = &tup->uport.state->xmit; tail = (unsigned long)&xmit->buf[xmit->tail]; count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE); if (!count) return; if (count < TEGRA_UART_MIN_DMA) tegra_uart_start_pio_tx(tup, count); else if (BYTES_TO_ALIGN(tail) > 0) tegra_uart_start_pio_tx(tup, BYTES_TO_ALIGN(tail)); else tegra_uart_start_tx_dma(tup, count); } /* Called by serial core driver with u->lock taken. */ static void tegra_uart_start_tx(struct uart_port *u) { struct tegra_uart_port *tup = to_tegra_uport(u); struct circ_buf *xmit = &u->state->xmit; if (!uart_circ_empty(xmit) && !tup->tx_in_progress) tegra_uart_start_next_tx(tup); } static unsigned int tegra_uart_tx_empty(struct uart_port *u) { struct tegra_uart_port *tup = to_tegra_uport(u); unsigned int ret = 0; unsigned long flags; spin_lock_irqsave(&u->lock, flags); if (!tup->tx_in_progress) { unsigned long lsr = tegra_uart_read(tup, UART_LSR); if ((lsr & TX_EMPTY_STATUS) == TX_EMPTY_STATUS) ret = TIOCSER_TEMT; } spin_unlock_irqrestore(&u->lock, flags); return ret; } static void tegra_uart_stop_tx(struct uart_port *u) { struct tegra_uart_port *tup = to_tegra_uport(u); struct circ_buf *xmit = &tup->uport.state->xmit; struct dma_tx_state state; unsigned int count; if (tup->tx_in_progress != TEGRA_UART_TX_DMA) return; dmaengine_terminate_all(tup->tx_dma_chan); dmaengine_tx_status(tup->tx_dma_chan, tup->tx_cookie, &state); count = tup->tx_bytes_requested - state.residue; async_tx_ack(tup->tx_dma_desc); xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1); tup->tx_in_progress = 0; } static void tegra_uart_handle_tx_pio(struct tegra_uart_port *tup) { struct circ_buf *xmit = &tup->uport.state->xmit; tegra_uart_fill_tx_fifo(tup, tup->tx_bytes); tup->tx_in_progress = 0; if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(&tup->uport); tegra_uart_start_next_tx(tup); } static void tegra_uart_handle_rx_pio(struct tegra_uart_port *tup, struct tty_port *tty) { do { char flag = TTY_NORMAL; unsigned long lsr = 0; unsigned char ch; lsr = tegra_uart_read(tup, UART_LSR); if (!(lsr & UART_LSR_DR)) break; flag = tegra_uart_decode_rx_error(tup, lsr); ch = (unsigned char) tegra_uart_read(tup, UART_RX); tup->uport.icount.rx++; if (!uart_handle_sysrq_char(&tup->uport, ch) && tty) tty_insert_flip_char(tty, ch, flag); } while (1); } static void tegra_uart_copy_rx_to_tty(struct tegra_uart_port *tup, struct tty_port *tty, unsigned int count) { int copied; /* If count is zero, then there is no data to be copied */ if (!count) return; tup->uport.icount.rx += count; if (!tty) { dev_err(tup->uport.dev, "No tty port\n"); return; } dma_sync_single_for_cpu(tup->uport.dev, tup->rx_dma_buf_phys, TEGRA_UART_RX_DMA_BUFFER_SIZE, DMA_FROM_DEVICE); copied = tty_insert_flip_string(tty, ((unsigned char *)(tup->rx_dma_buf_virt)), count); if (copied != count) { WARN_ON(1); dev_err(tup->uport.dev, "RxData copy to tty layer failed\n"); } dma_sync_single_for_device(tup->uport.dev, tup->rx_dma_buf_phys, TEGRA_UART_RX_DMA_BUFFER_SIZE, DMA_TO_DEVICE); } static void tegra_uart_rx_buffer_push(struct tegra_uart_port *tup, unsigned int residue) { struct tty_port *port = &tup->uport.state->port; struct tty_struct *tty = tty_port_tty_get(port); unsigned int count; async_tx_ack(tup->rx_dma_desc); count = tup->rx_bytes_requested - residue; /* If we are here, DMA is stopped */ tegra_uart_copy_rx_to_tty(tup, port, count); tegra_uart_handle_rx_pio(tup, port); if (tty) { tty_flip_buffer_push(port); tty_kref_put(tty); } } static void tegra_uart_rx_dma_complete(void *args) { struct tegra_uart_port *tup = args; struct uart_port *u = &tup->uport; unsigned long flags; struct dma_tx_state state; enum dma_status status; spin_lock_irqsave(&u->lock, flags); status = dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state); if (status == DMA_IN_PROGRESS) { dev_dbg(tup->uport.dev, "RX DMA is in progress\n"); goto done; } /* Deactivate flow control to stop sender */ if (tup->rts_active) set_rts(tup, false); tegra_uart_rx_buffer_push(tup, 0); tegra_uart_start_rx_dma(tup); /* Activate flow control to start transfer */ if (tup->rts_active) set_rts(tup, true); done: spin_unlock_irqrestore(&u->lock, flags); } static void tegra_uart_handle_rx_dma(struct tegra_uart_port *tup) { struct dma_tx_state state; /* Deactivate flow control to stop sender */ if (tup->rts_active) set_rts(tup, false); dmaengine_terminate_all(tup->rx_dma_chan); dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state); tegra_uart_rx_buffer_push(tup, state.residue); tegra_uart_start_rx_dma(tup); if (tup->rts_active) set_rts(tup, true); } static int tegra_uart_start_rx_dma(struct tegra_uart_port *tup) { unsigned int count = TEGRA_UART_RX_DMA_BUFFER_SIZE; tup->rx_dma_desc = dmaengine_prep_slave_single(tup->rx_dma_chan, tup->rx_dma_buf_phys, count, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT); if (!tup->rx_dma_desc) { dev_err(tup->uport.dev, "Not able to get desc for Rx\n"); return -EIO; } tup->rx_dma_desc->callback = tegra_uart_rx_dma_complete; tup->rx_dma_desc->callback_param = tup; dma_sync_single_for_device(tup->uport.dev, tup->rx_dma_buf_phys, count, DMA_TO_DEVICE); tup->rx_bytes_requested = count; tup->rx_cookie = dmaengine_submit(tup->rx_dma_desc); dma_async_issue_pending(tup->rx_dma_chan); return 0; } static void tegra_uart_handle_modem_signal_change(struct uart_port *u) { struct tegra_uart_port *tup = to_tegra_uport(u); unsigned long msr; msr = tegra_uart_read(tup, UART_MSR); if (!(msr & UART_MSR_ANY_DELTA)) return; if (msr & UART_MSR_TERI) tup->uport.icount.rng++; if (msr & UART_MSR_DDSR) tup->uport.icount.dsr++; /* We may only get DDCD when HW init and reset */ if (msr & UART_MSR_DDCD) uart_handle_dcd_change(&tup->uport, msr & UART_MSR_DCD); /* Will start/stop_tx accordingly */ if (msr & UART_MSR_DCTS) uart_handle_cts_change(&tup->uport, msr & UART_MSR_CTS); } static irqreturn_t tegra_uart_isr(int irq, void *data) { struct tegra_uart_port *tup = data; struct uart_port *u = &tup->uport; unsigned long iir; unsigned long ier; bool is_rx_int = false; unsigned long flags; spin_lock_irqsave(&u->lock, flags); while (1) { iir = tegra_uart_read(tup, UART_IIR); if (iir & UART_IIR_NO_INT) { if (is_rx_int) { tegra_uart_handle_rx_dma(tup); if (tup->rx_in_progress) { ier = tup->ier_shadow; ier |= (UART_IER_RLSI | UART_IER_RTOIE | TEGRA_UART_IER_EORD); tup->ier_shadow = ier; tegra_uart_write(tup, ier, UART_IER); } } spin_unlock_irqrestore(&u->lock, flags); return IRQ_HANDLED; } switch ((iir >> 1) & 0x7) { case 0: /* Modem signal change interrupt */ tegra_uart_handle_modem_signal_change(u); break; case 1: /* Transmit interrupt only triggered when using PIO */ tup->ier_shadow &= ~UART_IER_THRI; tegra_uart_write(tup, tup->ier_shadow, UART_IER); tegra_uart_handle_tx_pio(tup); break; case 4: /* End of data */ case 6: /* Rx timeout */ case 2: /* Receive */ if (!is_rx_int) { is_rx_int = true; /* Disable Rx interrupts */ ier = tup->ier_shadow; ier |= UART_IER_RDI; tegra_uart_write(tup, ier, UART_IER); ier &= ~(UART_IER_RDI | UART_IER_RLSI | UART_IER_RTOIE | TEGRA_UART_IER_EORD); tup->ier_shadow = ier; tegra_uart_write(tup, ier, UART_IER); } break; case 3: /* Receive error */ tegra_uart_decode_rx_error(tup, tegra_uart_read(tup, UART_LSR)); break; case 5: /* break nothing to handle */ case 7: /* break nothing to handle */ break; } } } static void tegra_uart_stop_rx(struct uart_port *u) { struct tegra_uart_port *tup = to_tegra_uport(u); struct dma_tx_state state; unsigned long ier; if (tup->rts_active) set_rts(tup, false); if (!tup->rx_in_progress) return; tegra_uart_wait_sym_time(tup, 1); /* wait one character interval */ ier = tup->ier_shadow; ier &= ~(UART_IER_RDI | UART_IER_RLSI | UART_IER_RTOIE | TEGRA_UART_IER_EORD); tup->ier_shadow = ier; tegra_uart_write(tup, ier, UART_IER); tup->rx_in_progress = 0; dmaengine_terminate_all(tup->rx_dma_chan); dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state); tegra_uart_rx_buffer_push(tup, state.residue); } static void tegra_uart_hw_deinit(struct tegra_uart_port *tup) { unsigned long flags; unsigned long char_time = DIV_ROUND_UP(10000000, tup->current_baud); unsigned long fifo_empty_time = tup->uport.fifosize * char_time; unsigned long wait_time; unsigned long lsr; unsigned long msr; unsigned long mcr; /* Disable interrupts */ tegra_uart_write(tup, 0, UART_IER); lsr = tegra_uart_read(tup, UART_LSR); if ((lsr & UART_LSR_TEMT) != UART_LSR_TEMT) { msr = tegra_uart_read(tup, UART_MSR); mcr = tegra_uart_read(tup, UART_MCR); if ((mcr & TEGRA_UART_MCR_CTS_EN) && (msr & UART_MSR_CTS)) dev_err(tup->uport.dev, "Tx Fifo not empty, CTS disabled, waiting\n"); /* Wait for Tx fifo to be empty */ while ((lsr & UART_LSR_TEMT) != UART_LSR_TEMT) { wait_time = min(fifo_empty_time, 100lu); udelay(wait_time); fifo_empty_time -= wait_time; if (!fifo_empty_time) { msr = tegra_uart_read(tup, UART_MSR); mcr = tegra_uart_read(tup, UART_MCR); if ((mcr & TEGRA_UART_MCR_CTS_EN) && (msr & UART_MSR_CTS)) dev_err(tup->uport.dev, "Slave not ready\n"); break; } lsr = tegra_uart_read(tup, UART_LSR); } } spin_lock_irqsave(&tup->uport.lock, flags); /* Reset the Rx and Tx FIFOs */ tegra_uart_fifo_reset(tup, UART_FCR_CLEAR_XMIT | UART_FCR_CLEAR_RCVR); tup->current_baud = 0; spin_unlock_irqrestore(&tup->uport.lock, flags); clk_disable_unprepare(tup->uart_clk); } static int tegra_uart_hw_init(struct tegra_uart_port *tup) { int ret; tup->fcr_shadow = 0; tup->mcr_shadow = 0; tup->lcr_shadow = 0; tup->ier_shadow = 0; tup->current_baud = 0; clk_prepare_enable(tup->uart_clk); /* Reset the UART controller to clear all previous status.*/ reset_control_assert(tup->rst); udelay(10); reset_control_deassert(tup->rst); tup->rx_in_progress = 0; tup->tx_in_progress = 0; /* * Set the trigger level * * For PIO mode: * * For receive, this will interrupt the CPU after that many number of * bytes are received, for the remaining bytes the receive timeout * interrupt is received. Rx high watermark is set to 4. * * For transmit, if the trasnmit interrupt is enabled, this will * interrupt the CPU when the number of entries in the FIFO reaches the * low watermark. Tx low watermark is set to 16 bytes. * * For DMA mode: * * Set the Tx trigger to 16. This should match the DMA burst size that * programmed in the DMA registers. */ tup->fcr_shadow = UART_FCR_ENABLE_FIFO; tup->fcr_shadow |= UART_FCR_R_TRIG_01; tup->fcr_shadow |= TEGRA_UART_TX_TRIG_16B; tegra_uart_write(tup, tup->fcr_shadow, UART_FCR); /* Dummy read to ensure the write is posted */ tegra_uart_read(tup, UART_SCR); /* * For all tegra devices (up to t210), there is a hardware issue that * requires software to wait for 3 UART clock periods after enabling * the TX fifo, otherwise data could be lost. */ tegra_uart_wait_cycle_time(tup, 3); /* * Initialize the UART with default configuration * (115200, N, 8, 1) so that the receive DMA buffer may be * enqueued */ tup->lcr_shadow = TEGRA_UART_DEFAULT_LSR; tegra_set_baudrate(tup, TEGRA_UART_DEFAULT_BAUD); tup->fcr_shadow |= UART_FCR_DMA_SELECT; tegra_uart_write(tup, tup->fcr_shadow, UART_FCR); ret = tegra_uart_start_rx_dma(tup); if (ret < 0) { dev_err(tup->uport.dev, "Not able to start Rx DMA\n"); return ret; } tup->rx_in_progress = 1; /* * Enable IE_RXS for the receive status interrupts like line errros. * Enable IE_RX_TIMEOUT to get the bytes which cannot be DMA'd. * * If using DMA mode, enable EORD instead of receive interrupt which * will interrupt after the UART is done with the receive instead of * the interrupt when the FIFO "threshold" is reached. * * EORD is different interrupt than RX_TIMEOUT - RX_TIMEOUT occurs when * the DATA is sitting in the FIFO and couldn't be transferred to the * DMA as the DMA size alignment (4 bytes) is not met. EORD will be * triggered when there is a pause of the incomming data stream for 4 * characters long. * * For pauses in the data which is not aligned to 4 bytes, we get * both the EORD as well as RX_TIMEOUT - SW sees RX_TIMEOUT first * then the EORD. */ tup->ier_shadow = UART_IER_RLSI | UART_IER_RTOIE | TEGRA_UART_IER_EORD; tegra_uart_write(tup, tup->ier_shadow, UART_IER); return 0; } static void tegra_uart_dma_channel_free(struct tegra_uart_port *tup, bool dma_to_memory) { if (dma_to_memory) { dmaengine_terminate_all(tup->rx_dma_chan); dma_release_channel(tup->rx_dma_chan); dma_free_coherent(tup->uport.dev, TEGRA_UART_RX_DMA_BUFFER_SIZE, tup->rx_dma_buf_virt, tup->rx_dma_buf_phys); tup->rx_dma_chan = NULL; tup->rx_dma_buf_phys = 0; tup->rx_dma_buf_virt = NULL; } else { dmaengine_terminate_all(tup->tx_dma_chan); dma_release_channel(tup->tx_dma_chan); dma_unmap_single(tup->uport.dev, tup->tx_dma_buf_phys, UART_XMIT_SIZE, DMA_TO_DEVICE); tup->tx_dma_chan = NULL; tup->tx_dma_buf_phys = 0; tup->tx_dma_buf_virt = NULL; } } static int tegra_uart_dma_channel_allocate(struct tegra_uart_port *tup, bool dma_to_memory) { struct dma_chan *dma_chan; unsigned char *dma_buf; dma_addr_t dma_phys; int ret; struct dma_slave_config dma_sconfig; dma_chan = dma_request_slave_channel_reason(tup->uport.dev, dma_to_memory ? "rx" : "tx"); if (IS_ERR(dma_chan)) { ret = PTR_ERR(dma_chan); dev_err(tup->uport.dev, "DMA channel alloc failed: %d\n", ret); return ret; } if (dma_to_memory) { dma_buf = dma_alloc_coherent(tup->uport.dev, TEGRA_UART_RX_DMA_BUFFER_SIZE, &dma_phys, GFP_KERNEL); if (!dma_buf) { dev_err(tup->uport.dev, "Not able to allocate the dma buffer\n"); dma_release_channel(dma_chan); return -ENOMEM; } dma_sconfig.src_addr = tup->uport.mapbase; dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; dma_sconfig.src_maxburst = 4; tup->rx_dma_chan = dma_chan; tup->rx_dma_buf_virt = dma_buf; tup->rx_dma_buf_phys = dma_phys; } else { dma_phys = dma_map_single(tup->uport.dev, tup->uport.state->xmit.buf, UART_XMIT_SIZE, DMA_TO_DEVICE); if (dma_mapping_error(tup->uport.dev, dma_phys)) { dev_err(tup->uport.dev, "dma_map_single tx failed\n"); dma_release_channel(dma_chan); return -ENOMEM; } dma_buf = tup->uport.state->xmit.buf; dma_sconfig.dst_addr = tup->uport.mapbase; dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; dma_sconfig.dst_maxburst = 16; tup->tx_dma_chan = dma_chan; tup->tx_dma_buf_virt = dma_buf; tup->tx_dma_buf_phys = dma_phys; } ret = dmaengine_slave_config(dma_chan, &dma_sconfig); if (ret < 0) { dev_err(tup->uport.dev, "Dma slave config failed, err = %d\n", ret); tegra_uart_dma_channel_free(tup, dma_to_memory); return ret; } return 0; } static int tegra_uart_startup(struct uart_port *u) { struct tegra_uart_port *tup = to_tegra_uport(u); int ret; ret = tegra_uart_dma_channel_allocate(tup, false); if (ret < 0) { dev_err(u->dev, "Tx Dma allocation failed, err = %d\n", ret); return ret; } ret = tegra_uart_dma_channel_allocate(tup, true); if (ret < 0) { dev_err(u->dev, "Rx Dma allocation failed, err = %d\n", ret); goto fail_rx_dma; } ret = tegra_uart_hw_init(tup); if (ret < 0) { dev_err(u->dev, "Uart HW init failed, err = %d\n", ret); goto fail_hw_init; } ret = request_irq(u->irq, tegra_uart_isr, 0, dev_name(u->dev), tup); if (ret < 0) { dev_err(u->dev, "Failed to register ISR for IRQ %d\n", u->irq); goto fail_hw_init; } return 0; fail_hw_init: tegra_uart_dma_channel_free(tup, true); fail_rx_dma: tegra_uart_dma_channel_free(tup, false); return ret; } /* * Flush any TX data submitted for DMA and PIO. Called when the * TX circular buffer is reset. */ static void tegra_uart_flush_buffer(struct uart_port *u) { struct tegra_uart_port *tup = to_tegra_uport(u); tup->tx_bytes = 0; if (tup->tx_dma_chan) dmaengine_terminate_all(tup->tx_dma_chan); } static void tegra_uart_shutdown(struct uart_port *u) { struct tegra_uart_port *tup = to_tegra_uport(u); tegra_uart_hw_deinit(tup); tup->rx_in_progress = 0; tup->tx_in_progress = 0; tegra_uart_dma_channel_free(tup, true); tegra_uart_dma_channel_free(tup, false); free_irq(u->irq, tup); } static void tegra_uart_enable_ms(struct uart_port *u) { struct tegra_uart_port *tup = to_tegra_uport(u); if (tup->enable_modem_interrupt) { tup->ier_shadow |= UART_IER_MSI; tegra_uart_write(tup, tup->ier_shadow, UART_IER); } } static void tegra_uart_set_termios(struct uart_port *u, struct ktermios *termios, struct ktermios *oldtermios) { struct tegra_uart_port *tup = to_tegra_uport(u); unsigned int baud; unsigned long flags; unsigned int lcr; int symb_bit = 1; struct clk *parent_clk = clk_get_parent(tup->uart_clk); unsigned long parent_clk_rate = clk_get_rate(parent_clk); int max_divider = (tup->cdata->support_clk_src_div) ? 0x7FFF : 0xFFFF; max_divider *= 16; spin_lock_irqsave(&u->lock, flags); /* Changing configuration, it is safe to stop any rx now */ if (tup->rts_active) set_rts(tup, false); /* Clear all interrupts as configuration is going to be changed */ tegra_uart_write(tup, tup->ier_shadow | UART_IER_RDI, UART_IER); tegra_uart_read(tup, UART_IER); tegra_uart_write(tup, 0, UART_IER); tegra_uart_read(tup, UART_IER); /* Parity */ lcr = tup->lcr_shadow; lcr &= ~UART_LCR_PARITY; /* CMSPAR isn't supported by this driver */ termios->c_cflag &= ~CMSPAR; if ((termios->c_cflag & PARENB) == PARENB) { symb_bit++; if (termios->c_cflag & PARODD) { lcr |= UART_LCR_PARITY; lcr &= ~UART_LCR_EPAR; lcr &= ~UART_LCR_SPAR; } else { lcr |= UART_LCR_PARITY; lcr |= UART_LCR_EPAR; lcr &= ~UART_LCR_SPAR; } } lcr &= ~UART_LCR_WLEN8; switch (termios->c_cflag & CSIZE) { case CS5: lcr |= UART_LCR_WLEN5; symb_bit += 5; break; case CS6: lcr |= UART_LCR_WLEN6; symb_bit += 6; break; case CS7: lcr |= UART_LCR_WLEN7; symb_bit += 7; break; default: lcr |= UART_LCR_WLEN8; symb_bit += 8; break; } /* Stop bits */ if (termios->c_cflag & CSTOPB) { lcr |= UART_LCR_STOP; symb_bit += 2; } else { lcr &= ~UART_LCR_STOP; symb_bit++; } tegra_uart_write(tup, lcr, UART_LCR); tup->lcr_shadow = lcr; tup->symb_bit = symb_bit; /* Baud rate. */ baud = uart_get_baud_rate(u, termios, oldtermios, parent_clk_rate/max_divider, parent_clk_rate/16); spin_unlock_irqrestore(&u->lock, flags); tegra_set_baudrate(tup, baud); if (tty_termios_baud_rate(termios)) tty_termios_encode_baud_rate(termios, baud, baud); spin_lock_irqsave(&u->lock, flags); /* Flow control */ if (termios->c_cflag & CRTSCTS) { tup->mcr_shadow |= TEGRA_UART_MCR_CTS_EN; tup->mcr_shadow &= ~TEGRA_UART_MCR_RTS_EN; tegra_uart_write(tup, tup->mcr_shadow, UART_MCR); /* if top layer has asked to set rts active then do so here */ if (tup->rts_active) set_rts(tup, true); } else { tup->mcr_shadow &= ~TEGRA_UART_MCR_CTS_EN; tup->mcr_shadow &= ~TEGRA_UART_MCR_RTS_EN; tegra_uart_write(tup, tup->mcr_shadow, UART_MCR); } /* update the port timeout based on new settings */ uart_update_timeout(u, termios->c_cflag, baud); /* Make sure all writes have completed */ tegra_uart_read(tup, UART_IER); /* Re-enable interrupt */ tegra_uart_write(tup, tup->ier_shadow, UART_IER); tegra_uart_read(tup, UART_IER); spin_unlock_irqrestore(&u->lock, flags); } static const char *tegra_uart_type(struct uart_port *u) { return TEGRA_UART_TYPE; } static const struct uart_ops tegra_uart_ops = { .tx_empty = tegra_uart_tx_empty, .set_mctrl = tegra_uart_set_mctrl, .get_mctrl = tegra_uart_get_mctrl, .stop_tx = tegra_uart_stop_tx, .start_tx = tegra_uart_start_tx, .stop_rx = tegra_uart_stop_rx, .flush_buffer = tegra_uart_flush_buffer, .enable_ms = tegra_uart_enable_ms, .break_ctl = tegra_uart_break_ctl, .startup = tegra_uart_startup, .shutdown = tegra_uart_shutdown, .set_termios = tegra_uart_set_termios, .type = tegra_uart_type, .request_port = tegra_uart_request_port, .release_port = tegra_uart_release_port, }; static struct uart_driver tegra_uart_driver = { .owner = THIS_MODULE, .driver_name = "tegra_hsuart", .dev_name = "ttyTHS", .cons = NULL, .nr = TEGRA_UART_MAXIMUM, }; static int tegra_uart_parse_dt(struct platform_device *pdev, struct tegra_uart_port *tup) { struct device_node *np = pdev->dev.of_node; int port; port = of_alias_get_id(np, "serial"); if (port < 0) { dev_err(&pdev->dev, "failed to get alias id, errno %d\n", port); return port; } tup->uport.line = port; tup->enable_modem_interrupt = of_property_read_bool(np, "nvidia,enable-modem-interrupt"); return 0; } static struct tegra_uart_chip_data tegra20_uart_chip_data = { .tx_fifo_full_status = false, .allow_txfifo_reset_fifo_mode = true, .support_clk_src_div = false, }; static struct tegra_uart_chip_data tegra30_uart_chip_data = { .tx_fifo_full_status = true, .allow_txfifo_reset_fifo_mode = false, .support_clk_src_div = true, }; static const struct of_device_id tegra_uart_of_match[] = { { .compatible = "nvidia,tegra30-hsuart", .data = &tegra30_uart_chip_data, }, { .compatible = "nvidia,tegra20-hsuart", .data = &tegra20_uart_chip_data, }, { }, }; MODULE_DEVICE_TABLE(of, tegra_uart_of_match); static int tegra_uart_probe(struct platform_device *pdev) { struct tegra_uart_port *tup; struct uart_port *u; struct resource *resource; int ret; const struct tegra_uart_chip_data *cdata; const struct of_device_id *match; match = of_match_device(tegra_uart_of_match, &pdev->dev); if (!match) { dev_err(&pdev->dev, "Error: No device match found\n"); return -ENODEV; } cdata = match->data; tup = devm_kzalloc(&pdev->dev, sizeof(*tup), GFP_KERNEL); if (!tup) { dev_err(&pdev->dev, "Failed to allocate memory for tup\n"); return -ENOMEM; } ret = tegra_uart_parse_dt(pdev, tup); if (ret < 0) return ret; u = &tup->uport; u->dev = &pdev->dev; u->ops = &tegra_uart_ops; u->type = PORT_TEGRA; u->fifosize = 32; tup->cdata = cdata; platform_set_drvdata(pdev, tup); resource = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!resource) { dev_err(&pdev->dev, "No IO memory resource\n"); return -ENODEV; } u->mapbase = resource->start; u->membase = devm_ioremap_resource(&pdev->dev, resource); if (IS_ERR(u->membase)) return PTR_ERR(u->membase); tup->uart_clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(tup->uart_clk)) { dev_err(&pdev->dev, "Couldn't get the clock\n"); return PTR_ERR(tup->uart_clk); } tup->rst = devm_reset_control_get_exclusive(&pdev->dev, "serial"); if (IS_ERR(tup->rst)) { dev_err(&pdev->dev, "Couldn't get the reset\n"); return PTR_ERR(tup->rst); } u->iotype = UPIO_MEM32; ret = platform_get_irq(pdev, 0); if (ret < 0) { dev_err(&pdev->dev, "Couldn't get IRQ\n"); return ret; } u->irq = ret; u->regshift = 2; ret = uart_add_one_port(&tegra_uart_driver, u); if (ret < 0) { dev_err(&pdev->dev, "Failed to add uart port, err %d\n", ret); return ret; } return ret; } static int tegra_uart_remove(struct platform_device *pdev) { struct tegra_uart_port *tup = platform_get_drvdata(pdev); struct uart_port *u = &tup->uport; uart_remove_one_port(&tegra_uart_driver, u); return 0; } #ifdef CONFIG_PM_SLEEP static int tegra_uart_suspend(struct device *dev) { struct tegra_uart_port *tup = dev_get_drvdata(dev); struct uart_port *u = &tup->uport; return uart_suspend_port(&tegra_uart_driver, u); } static int tegra_uart_resume(struct device *dev) { struct tegra_uart_port *tup = dev_get_drvdata(dev); struct uart_port *u = &tup->uport; return uart_resume_port(&tegra_uart_driver, u); } #endif static const struct dev_pm_ops tegra_uart_pm_ops = { SET_SYSTEM_SLEEP_PM_OPS(tegra_uart_suspend, tegra_uart_resume) }; static struct platform_driver tegra_uart_platform_driver = { .probe = tegra_uart_probe, .remove = tegra_uart_remove, .driver = { .name = "serial-tegra", .of_match_table = tegra_uart_of_match, .pm = &tegra_uart_pm_ops, }, }; static int __init tegra_uart_init(void) { int ret; ret = uart_register_driver(&tegra_uart_driver); if (ret < 0) { pr_err("Could not register %s driver\n", tegra_uart_driver.driver_name); return ret; } ret = platform_driver_register(&tegra_uart_platform_driver); if (ret < 0) { pr_err("Uart platform driver register failed, e = %d\n", ret); uart_unregister_driver(&tegra_uart_driver); return ret; } return 0; } static void __exit tegra_uart_exit(void) { pr_info("Unloading tegra uart driver\n"); platform_driver_unregister(&tegra_uart_platform_driver); uart_unregister_driver(&tegra_uart_driver); } module_init(tegra_uart_init); module_exit(tegra_uart_exit); MODULE_ALIAS("platform:serial-tegra"); MODULE_DESCRIPTION("High speed UART driver for tegra chipset"); MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>"); MODULE_LICENSE("GPL v2");
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with Cregit http://github.com/cregit/cregit
Version 2.0-RC1