| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Sascha Hauer | 3079 | 24.67% | 21 | 7.72% |
| Uwe Kleine-König | 2858 | 22.90% | 42 | 15.44% |
| Huang Shijie | 1373 | 11.00% | 16 | 5.88% |
| Sergey Organov | 479 | 3.84% | 15 | 5.51% |
| Shenwei Wang | 431 | 3.45% | 1 | 0.37% |
| Fabio Estevam | 382 | 3.06% | 17 | 6.25% |
| Nandor Han | 352 | 2.82% | 3 | 1.10% |
| Shawn Guo | 211 | 1.69% | 4 | 1.47% |
| Jiada Wang | 202 | 1.62% | 8 | 2.94% |
| Eduardo Valentin | 200 | 1.60% | 3 | 1.10% |
| Dirk Behme | 194 | 1.55% | 8 | 2.94% |
| Fabian Godehardt | 185 | 1.48% | 3 | 1.10% |
| Rasmus Villemoes | 163 | 1.31% | 1 | 0.37% |
| Marek Vašut | 119 | 0.95% | 1 | 0.37% |
| Saleem Abdulrasool | 103 | 0.83% | 1 | 0.37% |
| Lucas Stach | 101 | 0.81% | 6 | 2.21% |
| Jiri Slaby (SUSE) | 97 | 0.78% | 1 | 0.37% |
| Daniel R Thompson | 96 | 0.77% | 1 | 0.37% |
| Thomas Gleixner | 94 | 0.75% | 2 | 0.74% |
| Stefan Agner | 89 | 0.71% | 1 | 0.37% |
| George Hilliard | 89 | 0.71% | 1 | 0.37% |
| Fabien Lahoudere | 89 | 0.71% | 2 | 0.74% |
| Philipp Zabel | 87 | 0.70% | 1 | 0.37% |
| Ahmad Fatoum | 84 | 0.67% | 1 | 0.37% |
| Anson Huang | 79 | 0.63% | 4 | 1.47% |
| Oskar Schirmer | 79 | 0.63% | 2 | 0.74% |
| Troy Kisky | 68 | 0.54% | 3 | 1.10% |
| Sebastian Reichel | 64 | 0.51% | 2 | 0.74% |
| Russell King | 60 | 0.48% | 6 | 2.21% |
| Xinyu Chen | 59 | 0.47% | 1 | 0.37% |
| Ilpo Järvinen | 56 | 0.45% | 3 | 1.10% |
| Peter Hurley | 55 | 0.44% | 1 | 0.37% |
| Martin Fuzzey | 51 | 0.41% | 1 | 0.37% |
| Christophe Jaillet | 49 | 0.39% | 1 | 0.37% |
| Hubert Feurstein | 39 | 0.31% | 1 | 0.37% |
| Baruch Siach | 35 | 0.28% | 1 | 0.37% |
| Christoph Niedermaier | 34 | 0.27% | 3 | 1.10% |
| Geert Uytterhoeven | 34 | 0.27% | 1 | 0.37% |
| Stefan Eichenberger | 33 | 0.26% | 2 | 0.74% |
| Lukas Wunner | 33 | 0.26% | 4 | 1.47% |
| Rickard x Andersson | 30 | 0.24% | 1 | 0.37% |
| Fugang Duan | 29 | 0.23% | 5 | 1.84% |
| Alexander Stein | 27 | 0.22% | 1 | 0.37% |
| Valentin Longchamp | 27 | 0.22% | 1 | 0.37% |
| Harald Seiler | 26 | 0.21% | 1 | 0.37% |
| Martin Kaiser | 26 | 0.21% | 1 | 0.37% |
| Rob Herring | 22 | 0.18% | 2 | 0.74% |
| Francesco Dolcini | 21 | 0.17% | 1 | 0.37% |
| Esben Haabendal | 21 | 0.17% | 1 | 0.37% |
| Sachin Kamat | 20 | 0.16% | 3 | 1.10% |
| Maxim Yu. Osipov | 18 | 0.14% | 1 | 0.37% |
| Peter Senna Tschudin | 16 | 0.13% | 1 | 0.37% |
| Kees Cook | 14 | 0.11% | 1 | 0.37% |
| Manfred Schlaegl | 13 | 0.10% | 1 | 0.37% |
| Wolfram Sang | 12 | 0.10% | 1 | 0.37% |
| Marc Kleine-Budde | 11 | 0.09% | 1 | 0.37% |
| Eric Lammerts | 10 | 0.08% | 1 | 0.37% |
| Robin Gong | 10 | 0.08% | 2 | 0.74% |
| Alexander Shiyan | 10 | 0.08% | 2 | 0.74% |
| Jingchang Lu | 9 | 0.07% | 1 | 0.37% |
| Paul Geurts | 8 | 0.06% | 1 | 0.37% |
| Dmitry Safonov | 8 | 0.06% | 1 | 0.37% |
| Jiri Slaby | 8 | 0.06% | 4 | 1.47% |
| Kay Sievers | 7 | 0.06% | 1 | 0.37% |
| Peng Fan | 7 | 0.06% | 2 | 0.74% |
| Martyn Welch | 7 | 0.06% | 2 | 0.74% |
| Alan Cox | 7 | 0.06% | 3 | 1.10% |
| Matthias Schiffer | 7 | 0.06% | 3 | 1.10% |
| Eric Nelson | 6 | 0.05% | 2 | 0.74% |
| Romain Perier | 6 | 0.05% | 1 | 0.37% |
| Greg Kroah-Hartman | 6 | 0.05% | 3 | 1.10% |
| Andrea Paterniani | 6 | 0.05% | 1 | 0.37% |
| Darius Augulis | 5 | 0.04% | 1 | 0.37% |
| Johan Hovold | 5 | 0.04% | 2 | 0.74% |
| Olof Johansson | 4 | 0.03% | 1 | 0.37% |
| Allen Pais | 3 | 0.02% | 1 | 0.37% |
| Yangtao Li | 3 | 0.02% | 1 | 0.37% |
| Sherry Sun | 3 | 0.02% | 2 | 0.74% |
| Richard Zhao | 2 | 0.02% | 1 | 0.37% |
| Mingrui Ren | 2 | 0.02% | 1 | 0.37% |
| phil eichinger | 2 | 0.02% | 1 | 0.37% |
| Linus Torvalds (pre-git) | 2 | 0.02% | 1 | 0.37% |
| Tomasz Moń | 2 | 0.02% | 1 | 0.37% |
| Daniel Glöckner | 1 | 0.01% | 1 | 0.37% |
| Sanjeev Sharma | 1 | 0.01% | 1 | 0.37% |
| Roel Kluin | 1 | 0.01% | 1 | 0.37% |
| Philipp Puschmann | 1 | 0.01% | 1 | 0.37% |
| Julia Lawall | 1 | 0.01% | 1 | 0.37% |
| Zheng Yongjun | 1 | 0.01% | 1 | 0.37% |
| Lucas De Marchi | 1 | 0.01% | 1 | 0.37% |
| Ian Jamison | 1 | 0.01% | 1 | 0.37% |
| Vincent Sanders | 1 | 0.01% | 1 | 0.37% |
| Linus Torvalds | 1 | 0.01% | 1 | 0.37% |
| Total | 12483 | 272 |
// SPDX-License-Identifier: GPL-2.0+ /* * Driver for Motorola/Freescale IMX serial ports * * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. * * Author: Sascha Hauer <sascha@saschahauer.de> * Copyright (C) 2004 Pengutronix */ #include <linux/circ_buf.h> #include <linux/module.h> #include <linux/ioport.h> #include <linux/init.h> #include <linux/console.h> #include <linux/sysrq.h> #include <linux/platform_device.h> #include <linux/tty.h> #include <linux/tty_flip.h> #include <linux/serial_core.h> #include <linux/serial.h> #include <linux/clk.h> #include <linux/delay.h> #include <linux/ktime.h> #include <linux/pinctrl/consumer.h> #include <linux/rational.h> #include <linux/slab.h> #include <linux/of.h> #include <linux/io.h> #include <linux/iopoll.h> #include <linux/dma-mapping.h> #include <asm/irq.h> #include <linux/dma/imx-dma.h> #include "serial_mctrl_gpio.h" /* Register definitions */ #define URXD0 0x0 /* Receiver Register */ #define URTX0 0x40 /* Transmitter Register */ #define UCR1 0x80 /* Control Register 1 */ #define UCR2 0x84 /* Control Register 2 */ #define UCR3 0x88 /* Control Register 3 */ #define UCR4 0x8c /* Control Register 4 */ #define UFCR 0x90 /* FIFO Control Register */ #define USR1 0x94 /* Status Register 1 */ #define USR2 0x98 /* Status Register 2 */ #define UESC 0x9c /* Escape Character Register */ #define UTIM 0xa0 /* Escape Timer Register */ #define UBIR 0xa4 /* BRM Incremental Register */ #define UBMR 0xa8 /* BRM Modulator Register */ #define UBRC 0xac /* Baud Rate Count Register */ #define IMX21_ONEMS 0xb0 /* One Millisecond register */ #define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */ #define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/ /* UART Control Register Bit Fields.*/ #define URXD_DUMMY_READ (1<<16) #define URXD_CHARRDY (1<<15) #define URXD_ERR (1<<14) #define URXD_OVRRUN (1<<13) #define URXD_FRMERR (1<<12) #define URXD_BRK (1<<11) #define URXD_PRERR (1<<10) #define URXD_RX_DATA (0xFF<<0) #define UCR1_ADEN (1<<15) /* Auto detect interrupt */ #define UCR1_ADBR (1<<14) /* Auto detect baud rate */ #define UCR1_TRDYEN (1<<13) /* Transmitter ready interrupt enable */ #define UCR1_IDEN (1<<12) /* Idle condition interrupt */ #define UCR1_ICD_REG(x) (((x) & 3) << 10) /* idle condition detect */ #define UCR1_RRDYEN (1<<9) /* Recv ready interrupt enable */ #define UCR1_RXDMAEN (1<<8) /* Recv ready DMA enable */ #define UCR1_IREN (1<<7) /* Infrared interface enable */ #define UCR1_TXMPTYEN (1<<6) /* Transimitter empty interrupt enable */ #define UCR1_RTSDEN (1<<5) /* RTS delta interrupt enable */ #define UCR1_SNDBRK (1<<4) /* Send break */ #define UCR1_TXDMAEN (1<<3) /* Transmitter ready DMA enable */ #define IMX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, i.mx1 only */ #define UCR1_ATDMAEN (1<<2) /* Aging DMA Timer Enable */ #define UCR1_DOZE (1<<1) /* Doze */ #define UCR1_UARTEN (1<<0) /* UART enabled */ #define UCR2_ESCI (1<<15) /* Escape seq interrupt enable */ #define UCR2_IRTS (1<<14) /* Ignore RTS pin */ #define UCR2_CTSC (1<<13) /* CTS pin control */ #define UCR2_CTS (1<<12) /* Clear to send */ #define UCR2_ESCEN (1<<11) /* Escape enable */ #define UCR2_PREN (1<<8) /* Parity enable */ #define UCR2_PROE (1<<7) /* Parity odd/even */ #define UCR2_STPB (1<<6) /* Stop */ #define UCR2_WS (1<<5) /* Word size */ #define UCR2_RTSEN (1<<4) /* Request to send interrupt enable */ #define UCR2_ATEN (1<<3) /* Aging Timer Enable */ #define UCR2_TXEN (1<<2) /* Transmitter enabled */ #define UCR2_RXEN (1<<1) /* Receiver enabled */ #define UCR2_SRST (1<<0) /* SW reset */ #define UCR3_DTREN (1<<13) /* DTR interrupt enable */ #define UCR3_PARERREN (1<<12) /* Parity enable */ #define UCR3_FRAERREN (1<<11) /* Frame error interrupt enable */ #define UCR3_DSR (1<<10) /* Data set ready */ #define UCR3_DCD (1<<9) /* Data carrier detect */ #define UCR3_RI (1<<8) /* Ring indicator */ #define UCR3_ADNIMP (1<<7) /* Autobaud Detection Not Improved */ #define UCR3_RXDSEN (1<<6) /* Receive status interrupt enable */ #define UCR3_AIRINTEN (1<<5) /* Async IR wake interrupt enable */ #define UCR3_AWAKEN (1<<4) /* Async wake interrupt enable */ #define UCR3_DTRDEN (1<<3) /* Data Terminal Ready Delta Enable. */ #define IMX21_UCR3_RXDMUXSEL (1<<2) /* RXD Muxed Input Select */ #define UCR3_INVT (1<<1) /* Inverted Infrared transmission */ #define UCR3_BPEN (1<<0) /* Preset registers enable */ #define UCR4_CTSTL_SHF 10 /* CTS trigger level shift */ #define UCR4_CTSTL_MASK 0x3F /* CTS trigger is 6 bits wide */ #define UCR4_INVR (1<<9) /* Inverted infrared reception */ #define UCR4_ENIRI (1<<8) /* Serial infrared interrupt enable */ #define UCR4_WKEN (1<<7) /* Wake interrupt enable */ #define UCR4_REF16 (1<<6) /* Ref freq 16 MHz */ #define UCR4_IDDMAEN (1<<6) /* DMA IDLE Condition Detected */ #define UCR4_IRSC (1<<5) /* IR special case */ #define UCR4_TCEN (1<<3) /* Transmit complete interrupt enable */ #define UCR4_BKEN (1<<2) /* Break condition interrupt enable */ #define UCR4_OREN (1<<1) /* Receiver overrun interrupt enable */ #define UCR4_DREN (1<<0) /* Recv data ready interrupt enable */ #define UFCR_RXTL_SHF 0 /* Receiver trigger level shift */ #define UFCR_RXTL_MASK 0x3F /* Receiver trigger 6 bits wide */ #define UFCR_DCEDTE (1<<6) /* DCE/DTE mode select */ #define UFCR_RFDIV (7<<7) /* Reference freq divider mask */ #define UFCR_RFDIV_REG(x) (((x) < 7 ? 6 - (x) : 6) << 7) #define UFCR_TXTL_SHF 10 /* Transmitter trigger level shift */ #define USR1_PARITYERR (1<<15) /* Parity error interrupt flag */ #define USR1_RTSS (1<<14) /* RTS pin status */ #define USR1_TRDY (1<<13) /* Transmitter ready interrupt/dma flag */ #define USR1_RTSD (1<<12) /* RTS delta */ #define USR1_ESCF (1<<11) /* Escape seq interrupt flag */ #define USR1_FRAMERR (1<<10) /* Frame error interrupt flag */ #define USR1_RRDY (1<<9) /* Receiver ready interrupt/dma flag */ #define USR1_AGTIM (1<<8) /* Ageing timer interrupt flag */ #define USR1_DTRD (1<<7) /* DTR Delta */ #define USR1_RXDS (1<<6) /* Receiver idle interrupt flag */ #define USR1_AIRINT (1<<5) /* Async IR wake interrupt flag */ #define USR1_AWAKE (1<<4) /* Aysnc wake interrupt flag */ #define USR2_ADET (1<<15) /* Auto baud rate detect complete */ #define USR2_TXFE (1<<14) /* Transmit buffer FIFO empty */ #define USR2_DTRF (1<<13) /* DTR edge interrupt flag */ #define USR2_IDLE (1<<12) /* Idle condition */ #define USR2_RIDELT (1<<10) /* Ring Interrupt Delta */ #define USR2_RIIN (1<<9) /* Ring Indicator Input */ #define USR2_IRINT (1<<8) /* Serial infrared interrupt flag */ #define USR2_WAKE (1<<7) /* Wake */ #define USR2_DCDIN (1<<5) /* Data Carrier Detect Input */ #define USR2_RTSF (1<<4) /* RTS edge interrupt flag */ #define USR2_TXDC (1<<3) /* Transmitter complete */ #define USR2_BRCD (1<<2) /* Break condition */ #define USR2_ORE (1<<1) /* Overrun error */ #define USR2_RDR (1<<0) /* Recv data ready */ #define UTS_FRCPERR (1<<13) /* Force parity error */ #define UTS_LOOP (1<<12) /* Loop tx and rx */ #define UTS_TXEMPTY (1<<6) /* TxFIFO empty */ #define UTS_RXEMPTY (1<<5) /* RxFIFO empty */ #define UTS_TXFULL (1<<4) /* TxFIFO full */ #define UTS_RXFULL (1<<3) /* RxFIFO full */ #define UTS_SOFTRST (1<<0) /* Software reset */ /* We've been assigned a range on the "Low-density serial ports" major */ #define SERIAL_IMX_MAJOR 207 #define MINOR_START 16 #define DEV_NAME "ttymxc" /* * This determines how often we check the modem status signals * for any change. They generally aren't connected to an IRQ * so we have to poll them. We also check immediately before * filling the TX fifo incase CTS has been dropped. */ #define MCTRL_TIMEOUT (250*HZ/1000) #define DRIVER_NAME "IMX-uart" #define UART_NR 8 /* i.MX21 type uart runs on all i.mx except i.MX1 and i.MX6q */ enum imx_uart_type { IMX1_UART, IMX21_UART, }; /* device type dependent stuff */ struct imx_uart_data { unsigned uts_reg; enum imx_uart_type devtype; }; enum imx_tx_state { OFF, WAIT_AFTER_RTS, SEND, WAIT_AFTER_SEND, }; struct imx_port { struct uart_port port; struct timer_list timer; unsigned int old_status; unsigned int have_rtscts:1; unsigned int have_rtsgpio:1; unsigned int dte_mode:1; unsigned int inverted_tx:1; unsigned int inverted_rx:1; struct clk *clk_ipg; struct clk *clk_per; const struct imx_uart_data *devdata; struct mctrl_gpios *gpios; /* counter to stop 0xff flood */ int idle_counter; /* DMA fields */ unsigned int dma_is_enabled:1; unsigned int dma_is_rxing:1; unsigned int dma_is_txing:1; struct dma_chan *dma_chan_rx, *dma_chan_tx; struct scatterlist rx_sgl, tx_sgl[2]; void *rx_buf; struct circ_buf rx_ring; unsigned int rx_buf_size; unsigned int rx_period_length; unsigned int rx_periods; dma_cookie_t rx_cookie; unsigned int tx_bytes; unsigned int dma_tx_nents; unsigned int saved_reg[10]; bool context_saved; enum imx_tx_state tx_state; struct hrtimer trigger_start_tx; struct hrtimer trigger_stop_tx; }; struct imx_port_ucrs { unsigned int ucr1; unsigned int ucr2; unsigned int ucr3; }; static const struct imx_uart_data imx_uart_imx1_devdata = { .uts_reg = IMX1_UTS, .devtype = IMX1_UART, }; static const struct imx_uart_data imx_uart_imx21_devdata = { .uts_reg = IMX21_UTS, .devtype = IMX21_UART, }; static const struct of_device_id imx_uart_dt_ids[] = { /* * For reasons unknown to me, some UART devices (e.g. imx6ul's) are * compatible to fsl,imx6q-uart, but not fsl,imx21-uart, while the * original imx6q's UART is compatible to fsl,imx21-uart. This driver * doesn't make any distinction between these two variants. */ { .compatible = "fsl,imx6q-uart", .data = &imx_uart_imx21_devdata, }, { .compatible = "fsl,imx1-uart", .data = &imx_uart_imx1_devdata, }, { .compatible = "fsl,imx21-uart", .data = &imx_uart_imx21_devdata, }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, imx_uart_dt_ids); static inline void imx_uart_writel(struct imx_port *sport, u32 val, u32 offset) { writel(val, sport->port.membase + offset); } static inline u32 imx_uart_readl(struct imx_port *sport, u32 offset) { return readl(sport->port.membase + offset); } static inline unsigned imx_uart_uts_reg(struct imx_port *sport) { return sport->devdata->uts_reg; } static inline int imx_uart_is_imx1(struct imx_port *sport) { return sport->devdata->devtype == IMX1_UART; } /* * Save and restore functions for UCR1, UCR2 and UCR3 registers */ #if IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE) static void imx_uart_ucrs_save(struct imx_port *sport, struct imx_port_ucrs *ucr) { /* save control registers */ ucr->ucr1 = imx_uart_readl(sport, UCR1); ucr->ucr2 = imx_uart_readl(sport, UCR2); ucr->ucr3 = imx_uart_readl(sport, UCR3); } static void imx_uart_ucrs_restore(struct imx_port *sport, struct imx_port_ucrs *ucr) { /* restore control registers */ imx_uart_writel(sport, ucr->ucr1, UCR1); imx_uart_writel(sport, ucr->ucr2, UCR2); imx_uart_writel(sport, ucr->ucr3, UCR3); } #endif /* called with port.lock taken and irqs caller dependent */ static void imx_uart_rts_active(struct imx_port *sport, u32 *ucr2) { *ucr2 &= ~(UCR2_CTSC | UCR2_CTS); mctrl_gpio_set(sport->gpios, sport->port.mctrl | TIOCM_RTS); } /* called with port.lock taken and irqs caller dependent */ static void imx_uart_rts_inactive(struct imx_port *sport, u32 *ucr2) { *ucr2 &= ~UCR2_CTSC; *ucr2 |= UCR2_CTS; mctrl_gpio_set(sport->gpios, sport->port.mctrl & ~TIOCM_RTS); } static void start_hrtimer_ms(struct hrtimer *hrt, unsigned long msec) { hrtimer_start(hrt, ms_to_ktime(msec), HRTIMER_MODE_REL); } /* called with port.lock taken and irqs off */ static void imx_uart_soft_reset(struct imx_port *sport) { int i = 10; u32 ucr2, ubir, ubmr, uts; /* * According to the Reference Manual description of the UART SRST bit: * * "Reset the transmit and receive state machines, * all FIFOs and register USR1, USR2, UBIR, UBMR, UBRC, URXD, UTXD * and UTS[6-3]". * * We don't need to restore the old values from USR1, USR2, URXD and * UTXD. UBRC is read only, so only save/restore the other three * registers. */ ubir = imx_uart_readl(sport, UBIR); ubmr = imx_uart_readl(sport, UBMR); uts = imx_uart_readl(sport, IMX21_UTS); ucr2 = imx_uart_readl(sport, UCR2); imx_uart_writel(sport, ucr2 & ~UCR2_SRST, UCR2); while (!(imx_uart_readl(sport, UCR2) & UCR2_SRST) && (--i > 0)) udelay(1); /* Restore the registers */ imx_uart_writel(sport, ubir, UBIR); imx_uart_writel(sport, ubmr, UBMR); imx_uart_writel(sport, uts, IMX21_UTS); sport->idle_counter = 0; } static void imx_uart_disable_loopback_rs485(struct imx_port *sport) { unsigned int uts; /* See SER_RS485_ENABLED/UTS_LOOP comment in imx_uart_probe() */ uts = imx_uart_readl(sport, imx_uart_uts_reg(sport)); uts &= ~UTS_LOOP; imx_uart_writel(sport, uts, imx_uart_uts_reg(sport)); } /* called with port.lock taken and irqs off */ static void imx_uart_start_rx(struct uart_port *port) { struct imx_port *sport = (struct imx_port *)port; unsigned int ucr1, ucr2; ucr1 = imx_uart_readl(sport, UCR1); ucr2 = imx_uart_readl(sport, UCR2); ucr2 |= UCR2_RXEN; if (sport->dma_is_enabled) { ucr1 |= UCR1_RXDMAEN | UCR1_ATDMAEN; } else { ucr1 |= UCR1_RRDYEN; ucr2 |= UCR2_ATEN; } /* Write UCR2 first as it includes RXEN */ imx_uart_writel(sport, ucr2, UCR2); imx_uart_writel(sport, ucr1, UCR1); imx_uart_disable_loopback_rs485(sport); } /* called with port.lock taken and irqs off */ static void imx_uart_stop_tx(struct uart_port *port) { struct imx_port *sport = (struct imx_port *)port; u32 ucr1, ucr4, usr2; if (sport->tx_state == OFF) return; /* * We are maybe in the SMP context, so if the DMA TX thread is running * on other cpu, we have to wait for it to finish. */ if (sport->dma_is_txing) return; ucr1 = imx_uart_readl(sport, UCR1); imx_uart_writel(sport, ucr1 & ~UCR1_TRDYEN, UCR1); ucr4 = imx_uart_readl(sport, UCR4); usr2 = imx_uart_readl(sport, USR2); if ((!(usr2 & USR2_TXDC)) && (ucr4 & UCR4_TCEN)) { /* The shifter is still busy, so retry once TC triggers */ return; } ucr4 &= ~UCR4_TCEN; imx_uart_writel(sport, ucr4, UCR4); /* in rs485 mode disable transmitter */ if (port->rs485.flags & SER_RS485_ENABLED) { if (sport->tx_state == SEND) { sport->tx_state = WAIT_AFTER_SEND; if (port->rs485.delay_rts_after_send > 0) { start_hrtimer_ms(&sport->trigger_stop_tx, port->rs485.delay_rts_after_send); return; } /* continue without any delay */ } if (sport->tx_state == WAIT_AFTER_RTS || sport->tx_state == WAIT_AFTER_SEND) { u32 ucr2; hrtimer_try_to_cancel(&sport->trigger_start_tx); ucr2 = imx_uart_readl(sport, UCR2); if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND) imx_uart_rts_active(sport, &ucr2); else imx_uart_rts_inactive(sport, &ucr2); imx_uart_writel(sport, ucr2, UCR2); if (!port->rs485_rx_during_tx_gpio) imx_uart_start_rx(port); sport->tx_state = OFF; } } else { sport->tx_state = OFF; } } static void imx_uart_stop_rx_with_loopback_ctrl(struct uart_port *port, bool loopback) { struct imx_port *sport = (struct imx_port *)port; u32 ucr1, ucr2, ucr4, uts; ucr1 = imx_uart_readl(sport, UCR1); ucr2 = imx_uart_readl(sport, UCR2); ucr4 = imx_uart_readl(sport, UCR4); if (sport->dma_is_enabled) { ucr1 &= ~(UCR1_RXDMAEN | UCR1_ATDMAEN); } else { ucr1 &= ~UCR1_RRDYEN; ucr2 &= ~UCR2_ATEN; ucr4 &= ~UCR4_OREN; } imx_uart_writel(sport, ucr1, UCR1); imx_uart_writel(sport, ucr4, UCR4); /* See SER_RS485_ENABLED/UTS_LOOP comment in imx_uart_probe() */ if (port->rs485.flags & SER_RS485_ENABLED && port->rs485.flags & SER_RS485_RTS_ON_SEND && sport->have_rtscts && !sport->have_rtsgpio && loopback) { uts = imx_uart_readl(sport, imx_uart_uts_reg(sport)); uts |= UTS_LOOP; imx_uart_writel(sport, uts, imx_uart_uts_reg(sport)); ucr2 |= UCR2_RXEN; } else { ucr2 &= ~UCR2_RXEN; } imx_uart_writel(sport, ucr2, UCR2); } /* called with port.lock taken and irqs off */ static void imx_uart_stop_rx(struct uart_port *port) { /* * Stop RX and enable loopback in order to make sure RS485 bus * is not blocked. Se comment in imx_uart_probe(). */ imx_uart_stop_rx_with_loopback_ctrl(port, true); } /* called with port.lock taken and irqs off */ static void imx_uart_enable_ms(struct uart_port *port) { struct imx_port *sport = (struct imx_port *)port; mod_timer(&sport->timer, jiffies); mctrl_gpio_enable_ms(sport->gpios); } static void imx_uart_dma_tx(struct imx_port *sport); /* called with port.lock taken and irqs off */ static inline void imx_uart_transmit_buffer(struct imx_port *sport) { struct tty_port *tport = &sport->port.state->port; unsigned char c; if (sport->port.x_char) { /* Send next char */ imx_uart_writel(sport, sport->port.x_char, URTX0); sport->port.icount.tx++; sport->port.x_char = 0; return; } if (kfifo_is_empty(&tport->xmit_fifo) || uart_tx_stopped(&sport->port)) { imx_uart_stop_tx(&sport->port); return; } if (sport->dma_is_enabled) { u32 ucr1; /* * We've just sent a X-char Ensure the TX DMA is enabled * and the TX IRQ is disabled. **/ ucr1 = imx_uart_readl(sport, UCR1); ucr1 &= ~UCR1_TRDYEN; if (sport->dma_is_txing) { ucr1 |= UCR1_TXDMAEN; imx_uart_writel(sport, ucr1, UCR1); } else { imx_uart_writel(sport, ucr1, UCR1); imx_uart_dma_tx(sport); } return; } while (!(imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL) && uart_fifo_get(&sport->port, &c)) imx_uart_writel(sport, c, URTX0); if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS) uart_write_wakeup(&sport->port); if (kfifo_is_empty(&tport->xmit_fifo)) imx_uart_stop_tx(&sport->port); } static void imx_uart_dma_tx_callback(void *data) { struct imx_port *sport = data; struct tty_port *tport = &sport->port.state->port; struct scatterlist *sgl = &sport->tx_sgl[0]; unsigned long flags; u32 ucr1; uart_port_lock_irqsave(&sport->port, &flags); dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE); ucr1 = imx_uart_readl(sport, UCR1); ucr1 &= ~UCR1_TXDMAEN; imx_uart_writel(sport, ucr1, UCR1); uart_xmit_advance(&sport->port, sport->tx_bytes); dev_dbg(sport->port.dev, "we finish the TX DMA.\n"); sport->dma_is_txing = 0; if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS) uart_write_wakeup(&sport->port); if (!kfifo_is_empty(&tport->xmit_fifo) && !uart_tx_stopped(&sport->port)) imx_uart_dma_tx(sport); else if (sport->port.rs485.flags & SER_RS485_ENABLED) { u32 ucr4 = imx_uart_readl(sport, UCR4); ucr4 |= UCR4_TCEN; imx_uart_writel(sport, ucr4, UCR4); } uart_port_unlock_irqrestore(&sport->port, flags); } /* called with port.lock taken and irqs off */ static void imx_uart_dma_tx(struct imx_port *sport) { struct tty_port *tport = &sport->port.state->port; struct scatterlist *sgl = sport->tx_sgl; struct dma_async_tx_descriptor *desc; struct dma_chan *chan = sport->dma_chan_tx; struct device *dev = sport->port.dev; u32 ucr1, ucr4; int ret; if (sport->dma_is_txing) return; ucr4 = imx_uart_readl(sport, UCR4); ucr4 &= ~UCR4_TCEN; imx_uart_writel(sport, ucr4, UCR4); sg_init_table(sgl, ARRAY_SIZE(sport->tx_sgl)); sport->tx_bytes = kfifo_len(&tport->xmit_fifo); sport->dma_tx_nents = kfifo_dma_out_prepare(&tport->xmit_fifo, sgl, ARRAY_SIZE(sport->tx_sgl), sport->tx_bytes); ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE); if (ret == 0) { dev_err(dev, "DMA mapping error for TX.\n"); return; } desc = dmaengine_prep_slave_sg(chan, sgl, ret, DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT); if (!desc) { dma_unmap_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE); dev_err(dev, "We cannot prepare for the TX slave dma!\n"); return; } desc->callback = imx_uart_dma_tx_callback; desc->callback_param = sport; dev_dbg(dev, "TX: prepare to send %u bytes by DMA.\n", sport->tx_bytes); ucr1 = imx_uart_readl(sport, UCR1); ucr1 |= UCR1_TXDMAEN; imx_uart_writel(sport, ucr1, UCR1); /* fire it */ sport->dma_is_txing = 1; dmaengine_submit(desc); dma_async_issue_pending(chan); return; } /* called with port.lock taken and irqs off */ static void imx_uart_start_tx(struct uart_port *port) { struct imx_port *sport = (struct imx_port *)port; struct tty_port *tport = &sport->port.state->port; u32 ucr1; if (!sport->port.x_char && kfifo_is_empty(&tport->xmit_fifo)) return; /* * We cannot simply do nothing here if sport->tx_state == SEND already * because UCR1_TXMPTYEN might already have been cleared in * imx_uart_stop_tx(), but tx_state is still SEND. */ if (port->rs485.flags & SER_RS485_ENABLED) { if (sport->tx_state == OFF) { u32 ucr2 = imx_uart_readl(sport, UCR2); if (port->rs485.flags & SER_RS485_RTS_ON_SEND) imx_uart_rts_active(sport, &ucr2); else imx_uart_rts_inactive(sport, &ucr2); imx_uart_writel(sport, ucr2, UCR2); /* * Since we are about to transmit we can not stop RX * with loopback enabled because that will make our * transmitted data being just looped to RX. */ if (!(port->rs485.flags & SER_RS485_RX_DURING_TX) && !port->rs485_rx_during_tx_gpio) imx_uart_stop_rx_with_loopback_ctrl(port, false); sport->tx_state = WAIT_AFTER_RTS; if (port->rs485.delay_rts_before_send > 0) { start_hrtimer_ms(&sport->trigger_start_tx, port->rs485.delay_rts_before_send); return; } /* continue without any delay */ } if (sport->tx_state == WAIT_AFTER_SEND || sport->tx_state == WAIT_AFTER_RTS) { hrtimer_try_to_cancel(&sport->trigger_stop_tx); /* * Enable transmitter and shifter empty irq only if DMA * is off. In the DMA case this is done in the * tx-callback. */ if (!sport->dma_is_enabled) { u32 ucr4 = imx_uart_readl(sport, UCR4); ucr4 |= UCR4_TCEN; imx_uart_writel(sport, ucr4, UCR4); } sport->tx_state = SEND; } } else { sport->tx_state = SEND; } if (!sport->dma_is_enabled) { ucr1 = imx_uart_readl(sport, UCR1); imx_uart_writel(sport, ucr1 | UCR1_TRDYEN, UCR1); } if (sport->dma_is_enabled) { if (sport->port.x_char) { /* We have X-char to send, so enable TX IRQ and * disable TX DMA to let TX interrupt to send X-char */ ucr1 = imx_uart_readl(sport, UCR1); ucr1 &= ~UCR1_TXDMAEN; ucr1 |= UCR1_TRDYEN; imx_uart_writel(sport, ucr1, UCR1); return; } if (!kfifo_is_empty(&tport->xmit_fifo) && !uart_tx_stopped(port)) imx_uart_dma_tx(sport); return; } } static irqreturn_t __imx_uart_rtsint(int irq, void *dev_id) { struct imx_port *sport = dev_id; u32 usr1; imx_uart_writel(sport, USR1_RTSD, USR1); usr1 = imx_uart_readl(sport, USR1) & USR1_RTSS; uart_handle_cts_change(&sport->port, usr1); wake_up_interruptible(&sport->port.state->port.delta_msr_wait); return IRQ_HANDLED; } static irqreturn_t imx_uart_rtsint(int irq, void *dev_id) { struct imx_port *sport = dev_id; irqreturn_t ret; uart_port_lock(&sport->port); ret = __imx_uart_rtsint(irq, dev_id); uart_port_unlock(&sport->port); return ret; } static irqreturn_t imx_uart_txint(int irq, void *dev_id) { struct imx_port *sport = dev_id; uart_port_lock(&sport->port); imx_uart_transmit_buffer(sport); uart_port_unlock(&sport->port); return IRQ_HANDLED; } /* Check if hardware Rx flood is in progress, and issue soft reset to stop it. * This is to be called from Rx ISRs only when some bytes were actually * received. * * A way to reproduce the flood (checked on iMX6SX) is: open iMX UART at 9600 * 8N1, and from external source send 0xf0 char at 115200 8N1. In about 90% of * cases this starts a flood of "receiving" of 0xff characters by the iMX6 UART * that is terminated by any activity on RxD line, or could be stopped by * issuing soft reset to the UART (just stop/start of RX does not help). Note * that what we do here is sending isolated start bit about 2.4 times shorter * than it is to be on UART configured baud rate. */ static void imx_uart_check_flood(struct imx_port *sport, u32 usr2) { /* To detect hardware 0xff flood we monitor RxD line between RX * interrupts to isolate "receiving" of char(s) with no activity * on RxD line, that'd never happen on actual data transfers. * * We use USR2_WAKE bit to check for activity on RxD line, but we have a * race here if we clear USR2_WAKE when receiving of a char is in * progress, so we might get RX interrupt later with USR2_WAKE bit * cleared. Note though that as we don't try to clear USR2_WAKE when we * detected no activity, this race may hide actual activity only once. * * Yet another case where receive interrupt may occur without RxD * activity is expiration of aging timer, so we consider this as well. * * We use 'idle_counter' to ensure that we got at least so many RX * interrupts without any detected activity on RxD line. 2 cases * described plus 1 to be on the safe side gives us a margin of 3, * below. In practice I was not able to produce a false positive to * induce soft reset at regular data transfers even using 1 as the * margin, so 3 is actually very strong. * * We count interrupts, not chars in 'idle-counter' for simplicity. */ if (usr2 & USR2_WAKE) { imx_uart_writel(sport, USR2_WAKE, USR2); sport->idle_counter = 0; } else if (++sport->idle_counter > 3) { dev_warn(sport->port.dev, "RX flood detected: soft reset."); imx_uart_soft_reset(sport); /* also clears 'sport->idle_counter' */ } } static irqreturn_t __imx_uart_rxint(int irq, void *dev_id) { struct imx_port *sport = dev_id; struct tty_port *port = &sport->port.state->port; u32 usr2, rx; /* If we received something, check for 0xff flood */ usr2 = imx_uart_readl(sport, USR2); if (usr2 & USR2_RDR) imx_uart_check_flood(sport, usr2); while ((rx = imx_uart_readl(sport, URXD0)) & URXD_CHARRDY) { unsigned int flg = TTY_NORMAL; sport->port.icount.rx++; if (unlikely(rx & URXD_ERR)) { if (rx & URXD_BRK) { sport->port.icount.brk++; if (uart_handle_break(&sport->port)) continue; } else if (rx & URXD_PRERR) sport->port.icount.parity++; else if (rx & URXD_FRMERR) sport->port.icount.frame++; if (rx & URXD_OVRRUN) sport->port.icount.overrun++; if (rx & sport->port.ignore_status_mask) continue; rx &= (sport->port.read_status_mask | 0xFF); if (rx & URXD_BRK) flg = TTY_BREAK; else if (rx & URXD_PRERR) flg = TTY_PARITY; else if (rx & URXD_FRMERR) flg = TTY_FRAME; if (rx & URXD_OVRRUN) flg = TTY_OVERRUN; sport->port.sysrq = 0; } else if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx)) { continue; } if (sport->port.ignore_status_mask & URXD_DUMMY_READ) continue; if (tty_insert_flip_char(port, rx, flg) == 0) sport->port.icount.buf_overrun++; } tty_flip_buffer_push(port); return IRQ_HANDLED; } static irqreturn_t imx_uart_rxint(int irq, void *dev_id) { struct imx_port *sport = dev_id; irqreturn_t ret; uart_port_lock(&sport->port); ret = __imx_uart_rxint(irq, dev_id); uart_port_unlock(&sport->port); return ret; } static void imx_uart_clear_rx_errors(struct imx_port *sport); /* * We have a modem side uart, so the meanings of RTS and CTS are inverted. */ static unsigned int imx_uart_get_hwmctrl(struct imx_port *sport) { unsigned int tmp = TIOCM_DSR; unsigned usr1 = imx_uart_readl(sport, USR1); unsigned usr2 = imx_uart_readl(sport, USR2); if (usr1 & USR1_RTSS) tmp |= TIOCM_CTS; /* in DCE mode DCDIN is always 0 */ if (!(usr2 & USR2_DCDIN)) tmp |= TIOCM_CAR; if (sport->dte_mode) if (!(imx_uart_readl(sport, USR2) & USR2_RIIN)) tmp |= TIOCM_RI; return tmp; } /* * Handle any change of modem status signal since we were last called. */ static void imx_uart_mctrl_check(struct imx_port *sport) { unsigned int status, changed; status = imx_uart_get_hwmctrl(sport); changed = status ^ sport->old_status; if (changed == 0) return; sport->old_status = status; if (changed & TIOCM_RI && status & TIOCM_RI) sport->port.icount.rng++; if (changed & TIOCM_DSR) sport->port.icount.dsr++; if (changed & TIOCM_CAR) uart_handle_dcd_change(&sport->port, status & TIOCM_CAR); if (changed & TIOCM_CTS) uart_handle_cts_change(&sport->port, status & TIOCM_CTS); wake_up_interruptible(&sport->port.state->port.delta_msr_wait); } static irqreturn_t imx_uart_int(int irq, void *dev_id) { struct imx_port *sport = dev_id; unsigned int usr1, usr2, ucr1, ucr2, ucr3, ucr4; irqreturn_t ret = IRQ_NONE; uart_port_lock(&sport->port); usr1 = imx_uart_readl(sport, USR1); usr2 = imx_uart_readl(sport, USR2); ucr1 = imx_uart_readl(sport, UCR1); ucr2 = imx_uart_readl(sport, UCR2); ucr3 = imx_uart_readl(sport, UCR3); ucr4 = imx_uart_readl(sport, UCR4); /* * Even if a condition is true that can trigger an irq only handle it if * the respective irq source is enabled. This prevents some undesired * actions, for example if a character that sits in the RX FIFO and that * should be fetched via DMA is tried to be fetched using PIO. Or the * receiver is currently off and so reading from URXD0 results in an * exception. So just mask the (raw) status bits for disabled irqs. */ if ((ucr1 & UCR1_RRDYEN) == 0) usr1 &= ~USR1_RRDY; if ((ucr2 & UCR2_ATEN) == 0) usr1 &= ~USR1_AGTIM; if ((ucr1 & UCR1_TRDYEN) == 0) usr1 &= ~USR1_TRDY; if ((ucr4 & UCR4_TCEN) == 0) usr2 &= ~USR2_TXDC; if ((ucr3 & UCR3_DTRDEN) == 0) usr1 &= ~USR1_DTRD; if ((ucr1 & UCR1_RTSDEN) == 0) usr1 &= ~USR1_RTSD; if ((ucr3 & UCR3_AWAKEN) == 0) usr1 &= ~USR1_AWAKE; if ((ucr4 & UCR4_OREN) == 0) usr2 &= ~USR2_ORE; if (usr1 & (USR1_RRDY | USR1_AGTIM)) { imx_uart_writel(sport, USR1_AGTIM, USR1); __imx_uart_rxint(irq, dev_id); ret = IRQ_HANDLED; } if ((usr1 & USR1_TRDY) || (usr2 & USR2_TXDC)) { imx_uart_transmit_buffer(sport); ret = IRQ_HANDLED; } if (usr1 & USR1_DTRD) { imx_uart_writel(sport, USR1_DTRD, USR1); imx_uart_mctrl_check(sport); ret = IRQ_HANDLED; } if (usr1 & USR1_RTSD) { __imx_uart_rtsint(irq, dev_id); ret = IRQ_HANDLED; } if (usr1 & USR1_AWAKE) { imx_uart_writel(sport, USR1_AWAKE, USR1); ret = IRQ_HANDLED; } if (usr2 & USR2_ORE) { sport->port.icount.overrun++; imx_uart_writel(sport, USR2_ORE, USR2); ret = IRQ_HANDLED; } uart_port_unlock(&sport->port); return ret; } /* * Return TIOCSER_TEMT when transmitter is not busy. */ static unsigned int imx_uart_tx_empty(struct uart_port *port) { struct imx_port *sport = (struct imx_port *)port; unsigned int ret; ret = (imx_uart_readl(sport, USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0; /* If the TX DMA is working, return 0. */ if (sport->dma_is_txing) ret = 0; return ret; } /* called with port.lock taken and irqs off */ static unsigned int imx_uart_get_mctrl(struct uart_port *port) { struct imx_port *sport = (struct imx_port *)port; unsigned int ret = imx_uart_get_hwmctrl(sport); mctrl_gpio_get(sport->gpios, &ret); return ret; } /* called with port.lock taken and irqs off */ static void imx_uart_set_mctrl(struct uart_port *port, unsigned int mctrl) { struct imx_port *sport = (struct imx_port *)port; u32 ucr3, uts; if (!(port->rs485.flags & SER_RS485_ENABLED)) { u32 ucr2; /* * Turn off autoRTS if RTS is lowered and restore autoRTS * setting if RTS is raised. */ ucr2 = imx_uart_readl(sport, UCR2); ucr2 &= ~(UCR2_CTS | UCR2_CTSC); if (mctrl & TIOCM_RTS) { ucr2 |= UCR2_CTS; /* * UCR2_IRTS is unset if and only if the port is * configured for CRTSCTS, so we use inverted UCR2_IRTS * to get the state to restore to. */ if (!(ucr2 & UCR2_IRTS)) ucr2 |= UCR2_CTSC; } imx_uart_writel(sport, ucr2, UCR2); } ucr3 = imx_uart_readl(sport, UCR3) & ~UCR3_DSR; if (!(mctrl & TIOCM_DTR)) ucr3 |= UCR3_DSR; imx_uart_writel(sport, ucr3, UCR3); uts = imx_uart_readl(sport, imx_uart_uts_reg(sport)) & ~UTS_LOOP; if (mctrl & TIOCM_LOOP) uts |= UTS_LOOP; imx_uart_writel(sport, uts, imx_uart_uts_reg(sport)); mctrl_gpio_set(sport->gpios, mctrl); } /* * Interrupts always disabled. */ static void imx_uart_break_ctl(struct uart_port *port, int break_state) { struct imx_port *sport = (struct imx_port *)port; unsigned long flags; u32 ucr1; uart_port_lock_irqsave(&sport->port, &flags); ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_SNDBRK; if (break_state != 0) ucr1 |= UCR1_SNDBRK; imx_uart_writel(sport, ucr1, UCR1); uart_port_unlock_irqrestore(&sport->port, flags); } /* * This is our per-port timeout handler, for checking the * modem status signals. */ static void imx_uart_timeout(struct timer_list *t) { struct imx_port *sport = from_timer(sport, t, timer); unsigned long flags; if (sport->port.state) { uart_port_lock_irqsave(&sport->port, &flags); imx_uart_mctrl_check(sport); uart_port_unlock_irqrestore(&sport->port, flags); mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT); } } /* * There are two kinds of RX DMA interrupts(such as in the MX6Q): * [1] the RX DMA buffer is full. * [2] the aging timer expires * * Condition [2] is triggered when a character has been sitting in the FIFO * for at least 8 byte durations. */ static void imx_uart_dma_rx_callback(void *data) { struct imx_port *sport = data; struct dma_chan *chan = sport->dma_chan_rx; struct scatterlist *sgl = &sport->rx_sgl; struct tty_port *port = &sport->port.state->port; struct dma_tx_state state; struct circ_buf *rx_ring = &sport->rx_ring; enum dma_status status; unsigned int w_bytes = 0; unsigned int r_bytes; unsigned int bd_size; status = dmaengine_tx_status(chan, sport->rx_cookie, &state); if (status == DMA_ERROR) { uart_port_lock(&sport->port); imx_uart_clear_rx_errors(sport); uart_port_unlock(&sport->port); return; } /* * The state-residue variable represents the empty space * relative to the entire buffer. Taking this in consideration * the head is always calculated base on the buffer total * length - DMA transaction residue. The UART script from the * SDMA firmware will jump to the next buffer descriptor, * once a DMA transaction if finalized (IMX53 RM - A.4.1.2.4). * Taking this in consideration the tail is always at the * beginning of the buffer descriptor that contains the head. */ /* Calculate the head */ rx_ring->head = sg_dma_len(sgl) - state.residue; /* Calculate the tail. */ bd_size = sg_dma_len(sgl) / sport->rx_periods; rx_ring->tail = ((rx_ring->head-1) / bd_size) * bd_size; if (rx_ring->head <= sg_dma_len(sgl) && rx_ring->head > rx_ring->tail) { /* Move data from tail to head */ r_bytes = rx_ring->head - rx_ring->tail; /* If we received something, check for 0xff flood */ uart_port_lock(&sport->port); imx_uart_check_flood(sport, imx_uart_readl(sport, USR2)); uart_port_unlock(&sport->port); if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ)) { /* CPU claims ownership of RX DMA buffer */ dma_sync_sg_for_cpu(sport->port.dev, sgl, 1, DMA_FROM_DEVICE); w_bytes = tty_insert_flip_string(port, sport->rx_buf + rx_ring->tail, r_bytes); /* UART retrieves ownership of RX DMA buffer */ dma_sync_sg_for_device(sport->port.dev, sgl, 1, DMA_FROM_DEVICE); if (w_bytes != r_bytes) sport->port.icount.buf_overrun++; sport->port.icount.rx += w_bytes; } } else { WARN_ON(rx_ring->head > sg_dma_len(sgl)); WARN_ON(rx_ring->head <= rx_ring->tail); } if (w_bytes) { tty_flip_buffer_push(port); dev_dbg(sport->port.dev, "We get %d bytes.\n", w_bytes); } } static int imx_uart_start_rx_dma(struct imx_port *sport) { struct scatterlist *sgl = &sport->rx_sgl; struct dma_chan *chan = sport->dma_chan_rx; struct device *dev = sport->port.dev; struct dma_async_tx_descriptor *desc; int ret; sport->rx_ring.head = 0; sport->rx_ring.tail = 0; sg_init_one(sgl, sport->rx_buf, sport->rx_buf_size); ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE); if (ret == 0) { dev_err(dev, "DMA mapping error for RX.\n"); return -EINVAL; } desc = dmaengine_prep_dma_cyclic(chan, sg_dma_address(sgl), sg_dma_len(sgl), sg_dma_len(sgl) / sport->rx_periods, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT); if (!desc) { dma_unmap_sg(dev, sgl, 1, DMA_FROM_DEVICE); dev_err(dev, "We cannot prepare for the RX slave dma!\n"); return -EINVAL; } desc->callback = imx_uart_dma_rx_callback; desc->callback_param = sport; dev_dbg(dev, "RX: prepare for the DMA.\n"); sport->dma_is_rxing = 1; sport->rx_cookie = dmaengine_submit(desc); dma_async_issue_pending(chan); return 0; } static void imx_uart_clear_rx_errors(struct imx_port *sport) { struct tty_port *port = &sport->port.state->port; u32 usr1, usr2; usr1 = imx_uart_readl(sport, USR1); usr2 = imx_uart_readl(sport, USR2); if (usr2 & USR2_BRCD) { sport->port.icount.brk++; imx_uart_writel(sport, USR2_BRCD, USR2); uart_handle_break(&sport->port); if (tty_insert_flip_char(port, 0, TTY_BREAK) == 0) sport->port.icount.buf_overrun++; tty_flip_buffer_push(port); } else { if (usr1 & USR1_FRAMERR) { sport->port.icount.frame++; imx_uart_writel(sport, USR1_FRAMERR, USR1); } else if (usr1 & USR1_PARITYERR) { sport->port.icount.parity++; imx_uart_writel(sport, USR1_PARITYERR, USR1); } } if (usr2 & USR2_ORE) { sport->port.icount.overrun++; imx_uart_writel(sport, USR2_ORE, USR2); } sport->idle_counter = 0; } #define TXTL_DEFAULT 8 #define RXTL_DEFAULT 8 /* 8 characters or aging timer */ #define TXTL_DMA 8 /* DMA burst setting */ #define RXTL_DMA 9 /* DMA burst setting */ static void imx_uart_setup_ufcr(struct imx_port *sport, unsigned char txwl, unsigned char rxwl) { unsigned int val; /* set receiver / transmitter trigger level */ val = imx_uart_readl(sport, UFCR) & (UFCR_RFDIV | UFCR_DCEDTE); val |= txwl << UFCR_TXTL_SHF | rxwl; imx_uart_writel(sport, val, UFCR); } static void imx_uart_dma_exit(struct imx_port *sport) { if (sport->dma_chan_rx) { dmaengine_terminate_sync(sport->dma_chan_rx); dma_release_channel(sport->dma_chan_rx); sport->dma_chan_rx = NULL; sport->rx_cookie = -EINVAL; kfree(sport->rx_buf); sport->rx_buf = NULL; } if (sport->dma_chan_tx) { dmaengine_terminate_sync(sport->dma_chan_tx); dma_release_channel(sport->dma_chan_tx); sport->dma_chan_tx = NULL; } } static int imx_uart_dma_init(struct imx_port *sport) { struct dma_slave_config slave_config = {}; struct device *dev = sport->port.dev; struct dma_chan *chan; int ret; /* Prepare for RX : */ chan = dma_request_chan(dev, "rx"); if (IS_ERR(chan)) { dev_dbg(dev, "cannot get the DMA channel.\n"); sport->dma_chan_rx = NULL; ret = PTR_ERR(chan); goto err; } sport->dma_chan_rx = chan; slave_config.direction = DMA_DEV_TO_MEM; slave_config.src_addr = sport->port.mapbase + URXD0; slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; /* one byte less than the watermark level to enable the aging timer */ slave_config.src_maxburst = RXTL_DMA - 1; ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config); if (ret) { dev_err(dev, "error in RX dma configuration.\n"); goto err; } sport->rx_buf_size = sport->rx_period_length * sport->rx_periods; sport->rx_buf = kzalloc(sport->rx_buf_size, GFP_KERNEL); if (!sport->rx_buf) { ret = -ENOMEM; goto err; } sport->rx_ring.buf = sport->rx_buf; /* Prepare for TX : */ chan = dma_request_chan(dev, "tx"); if (IS_ERR(chan)) { dev_err(dev, "cannot get the TX DMA channel!\n"); sport->dma_chan_tx = NULL; ret = PTR_ERR(chan); goto err; } sport->dma_chan_tx = chan; slave_config.direction = DMA_MEM_TO_DEV; slave_config.dst_addr = sport->port.mapbase + URTX0; slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; slave_config.dst_maxburst = TXTL_DMA; ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config); if (ret) { dev_err(dev, "error in TX dma configuration."); goto err; } return 0; err: imx_uart_dma_exit(sport); return ret; } static void imx_uart_enable_dma(struct imx_port *sport) { u32 ucr1; imx_uart_setup_ufcr(sport, TXTL_DMA, RXTL_DMA); /* set UCR1 */ ucr1 = imx_uart_readl(sport, UCR1); ucr1 |= UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN; imx_uart_writel(sport, ucr1, UCR1); sport->dma_is_enabled = 1; } static void imx_uart_disable_dma(struct imx_port *sport) { u32 ucr1; /* clear UCR1 */ ucr1 = imx_uart_readl(sport, UCR1); ucr1 &= ~(UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN); imx_uart_writel(sport, ucr1, UCR1); imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT); sport->dma_is_enabled = 0; } /* half the RX buffer size */ #define CTSTL 16 static int imx_uart_startup(struct uart_port *port) { struct imx_port *sport = (struct imx_port *)port; int retval; unsigned long flags; int dma_is_inited = 0; u32 ucr1, ucr2, ucr3, ucr4; retval = clk_prepare_enable(sport->clk_per); if (retval) return retval; retval = clk_prepare_enable(sport->clk_ipg); if (retval) { clk_disable_unprepare(sport->clk_per); return retval; } imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT); /* disable the DREN bit (Data Ready interrupt enable) before * requesting IRQs */ ucr4 = imx_uart_readl(sport, UCR4); /* set the trigger level for CTS */ ucr4 &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF); ucr4 |= CTSTL << UCR4_CTSTL_SHF; imx_uart_writel(sport, ucr4 & ~UCR4_DREN, UCR4); /* Can we enable the DMA support? */ if (!uart_console(port) && imx_uart_dma_init(sport) == 0) { lockdep_set_subclass(&port->lock, 1); dma_is_inited = 1; } uart_port_lock_irqsave(&sport->port, &flags); /* Reset fifo's and state machines */ imx_uart_soft_reset(sport); /* * Finally, clear and enable interrupts */ imx_uart_writel(sport, USR1_RTSD | USR1_DTRD, USR1); imx_uart_writel(sport, USR2_ORE, USR2); ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_RRDYEN; ucr1 |= UCR1_UARTEN; if (sport->have_rtscts) ucr1 |= UCR1_RTSDEN; imx_uart_writel(sport, ucr1, UCR1); ucr4 = imx_uart_readl(sport, UCR4) & ~(UCR4_OREN | UCR4_INVR); if (!dma_is_inited) ucr4 |= UCR4_OREN; if (sport->inverted_rx) ucr4 |= UCR4_INVR; imx_uart_writel(sport, ucr4, UCR4); ucr3 = imx_uart_readl(sport, UCR3) & ~UCR3_INVT; /* * configure tx polarity before enabling tx */ if (sport->inverted_tx) ucr3 |= UCR3_INVT; if (!imx_uart_is_imx1(sport)) { ucr3 |= UCR3_DTRDEN | UCR3_RI | UCR3_DCD; if (sport->dte_mode) /* disable broken interrupts */ ucr3 &= ~(UCR3_RI | UCR3_DCD); } imx_uart_writel(sport, ucr3, UCR3); ucr2 = imx_uart_readl(sport, UCR2) & ~UCR2_ATEN; ucr2 |= (UCR2_RXEN | UCR2_TXEN); if (!sport->have_rtscts) ucr2 |= UCR2_IRTS; /* * make sure the edge sensitive RTS-irq is disabled, * we're using RTSD instead. */ if (!imx_uart_is_imx1(sport)) ucr2 &= ~UCR2_RTSEN; imx_uart_writel(sport, ucr2, UCR2); /* * Enable modem status interrupts */ imx_uart_enable_ms(&sport->port); if (dma_is_inited) { imx_uart_enable_dma(sport); imx_uart_start_rx_dma(sport); } else { ucr1 = imx_uart_readl(sport, UCR1); ucr1 |= UCR1_RRDYEN; imx_uart_writel(sport, ucr1, UCR1); ucr2 = imx_uart_readl(sport, UCR2); ucr2 |= UCR2_ATEN; imx_uart_writel(sport, ucr2, UCR2); } imx_uart_disable_loopback_rs485(sport); uart_port_unlock_irqrestore(&sport->port, flags); return 0; } static void imx_uart_shutdown(struct uart_port *port) { struct imx_port *sport = (struct imx_port *)port; unsigned long flags; u32 ucr1, ucr2, ucr4, uts; int loops; if (sport->dma_is_enabled) { dmaengine_terminate_sync(sport->dma_chan_tx); if (sport->dma_is_txing) { dma_unmap_sg(sport->port.dev, &sport->tx_sgl[0], sport->dma_tx_nents, DMA_TO_DEVICE); sport->dma_is_txing = 0; } dmaengine_terminate_sync(sport->dma_chan_rx); if (sport->dma_is_rxing) { dma_unmap_sg(sport->port.dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE); sport->dma_is_rxing = 0; } uart_port_lock_irqsave(&sport->port, &flags); imx_uart_stop_tx(port); imx_uart_stop_rx(port); imx_uart_disable_dma(sport); uart_port_unlock_irqrestore(&sport->port, flags); imx_uart_dma_exit(sport); } mctrl_gpio_disable_ms(sport->gpios); uart_port_lock_irqsave(&sport->port, &flags); ucr2 = imx_uart_readl(sport, UCR2); ucr2 &= ~(UCR2_TXEN | UCR2_ATEN); imx_uart_writel(sport, ucr2, UCR2); uart_port_unlock_irqrestore(&sport->port, flags); /* * Stop our timer. */ del_timer_sync(&sport->timer); /* * Disable all interrupts, port and break condition. */ uart_port_lock_irqsave(&sport->port, &flags); ucr1 = imx_uart_readl(sport, UCR1); ucr1 &= ~(UCR1_TRDYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_RXDMAEN | UCR1_ATDMAEN | UCR1_SNDBRK); /* See SER_RS485_ENABLED/UTS_LOOP comment in imx_uart_probe() */ if (port->rs485.flags & SER_RS485_ENABLED && port->rs485.flags & SER_RS485_RTS_ON_SEND && sport->have_rtscts && !sport->have_rtsgpio) { uts = imx_uart_readl(sport, imx_uart_uts_reg(sport)); uts |= UTS_LOOP; imx_uart_writel(sport, uts, imx_uart_uts_reg(sport)); ucr1 |= UCR1_UARTEN; } else { ucr1 &= ~UCR1_UARTEN; } imx_uart_writel(sport, ucr1, UCR1); ucr4 = imx_uart_readl(sport, UCR4); ucr4 &= ~UCR4_TCEN; imx_uart_writel(sport, ucr4, UCR4); /* * We have to ensure the tx state machine ends up in OFF. This * is especially important for rs485 where we must not leave * the RTS signal high, blocking the bus indefinitely. * * All interrupts are now disabled, so imx_uart_stop_tx() will * no longer be called from imx_uart_transmit_buffer(). It may * still be called via the hrtimers, and if those are in play, * we have to honour the delays. */ if (sport->tx_state == WAIT_AFTER_RTS || sport->tx_state == SEND) imx_uart_stop_tx(port); /* * In many cases (rs232 mode, or if tx_state was * WAIT_AFTER_RTS, or if tx_state was SEND and there is no * delay_rts_after_send), this will have moved directly to * OFF. In rs485 mode, tx_state might already have been * WAIT_AFTER_SEND and the hrtimer thus already started, or * the above imx_uart_stop_tx() call could have started it. In * those cases, we have to wait for the hrtimer to fire and * complete the transition to OFF. */ loops = port->rs485.flags & SER_RS485_ENABLED ? port->rs485.delay_rts_after_send : 0; while (sport->tx_state != OFF && loops--) { uart_port_unlock_irqrestore(&sport->port, flags); msleep(1); uart_port_lock_irqsave(&sport->port, &flags); } if (sport->tx_state != OFF) { dev_warn(sport->port.dev, "unexpected tx_state %d\n", sport->tx_state); /* * This machine may be busted, but ensure the RTS * signal is inactive in order not to block other * devices. */ if (port->rs485.flags & SER_RS485_ENABLED) { ucr2 = imx_uart_readl(sport, UCR2); if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND) imx_uart_rts_active(sport, &ucr2); else imx_uart_rts_inactive(sport, &ucr2); imx_uart_writel(sport, ucr2, UCR2); } sport->tx_state = OFF; } uart_port_unlock_irqrestore(&sport->port, flags); clk_disable_unprepare(sport->clk_per); clk_disable_unprepare(sport->clk_ipg); } /* called with port.lock taken and irqs off */ static void imx_uart_flush_buffer(struct uart_port *port) { struct imx_port *sport = (struct imx_port *)port; struct scatterlist *sgl = &sport->tx_sgl[0]; if (!sport->dma_chan_tx) return; sport->tx_bytes = 0; dmaengine_terminate_all(sport->dma_chan_tx); if (sport->dma_is_txing) { u32 ucr1; dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE); ucr1 = imx_uart_readl(sport, UCR1); ucr1 &= ~UCR1_TXDMAEN; imx_uart_writel(sport, ucr1, UCR1); sport->dma_is_txing = 0; } imx_uart_soft_reset(sport); } static void imx_uart_set_termios(struct uart_port *port, struct ktermios *termios, const struct ktermios *old) { struct imx_port *sport = (struct imx_port *)port; unsigned long flags; u32 ucr2, old_ucr2, ufcr; unsigned int baud, quot; unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8; unsigned long div; unsigned long num, denom, old_ubir, old_ubmr; uint64_t tdiv64; /* * We only support CS7 and CS8. */ while ((termios->c_cflag & CSIZE) != CS7 && (termios->c_cflag & CSIZE) != CS8) { termios->c_cflag &= ~CSIZE; termios->c_cflag |= old_csize; old_csize = CS8; } del_timer_sync(&sport->timer); /* * Ask the core to calculate the divisor for us. */ baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16); quot = uart_get_divisor(port, baud); uart_port_lock_irqsave(&sport->port, &flags); /* * Read current UCR2 and save it for future use, then clear all the bits * except those we will or may need to preserve. */ old_ucr2 = imx_uart_readl(sport, UCR2); ucr2 = old_ucr2 & (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN | UCR2_CTS); ucr2 |= UCR2_SRST | UCR2_IRTS; if ((termios->c_cflag & CSIZE) == CS8) ucr2 |= UCR2_WS; if (!sport->have_rtscts) termios->c_cflag &= ~CRTSCTS; if (port->rs485.flags & SER_RS485_ENABLED) { /* * RTS is mandatory for rs485 operation, so keep * it under manual control and keep transmitter * disabled. */ if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND) imx_uart_rts_active(sport, &ucr2); else imx_uart_rts_inactive(sport, &ucr2); } else if (termios->c_cflag & CRTSCTS) { /* * Only let receiver control RTS output if we were not requested * to have RTS inactive (which then should take precedence). */ if (ucr2 & UCR2_CTS) ucr2 |= UCR2_CTSC; } if (termios->c_cflag & CRTSCTS) ucr2 &= ~UCR2_IRTS; if (termios->c_cflag & CSTOPB) ucr2 |= UCR2_STPB; if (termios->c_cflag & PARENB) { ucr2 |= UCR2_PREN; if (termios->c_cflag & PARODD) ucr2 |= UCR2_PROE; } sport->port.read_status_mask = 0; if (termios->c_iflag & INPCK) sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR); if (termios->c_iflag & (BRKINT | PARMRK)) sport->port.read_status_mask |= URXD_BRK; /* * Characters to ignore */ sport->port.ignore_status_mask = 0; if (termios->c_iflag & IGNPAR) sport->port.ignore_status_mask |= URXD_PRERR | URXD_FRMERR; if (termios->c_iflag & IGNBRK) { sport->port.ignore_status_mask |= URXD_BRK; /* * If we're ignoring parity and break indicators, * ignore overruns too (for real raw support). */ if (termios->c_iflag & IGNPAR) sport->port.ignore_status_mask |= URXD_OVRRUN; } if ((termios->c_cflag & CREAD) == 0) sport->port.ignore_status_mask |= URXD_DUMMY_READ; /* * Update the per-port timeout. */ uart_update_timeout(port, termios->c_cflag, baud); /* custom-baudrate handling */ div = sport->port.uartclk / (baud * 16); if (baud == 38400 && quot != div) baud = sport->port.uartclk / (quot * 16); div = sport->port.uartclk / (baud * 16); if (div > 7) div = 7; if (!div) div = 1; rational_best_approximation(16 * div * baud, sport->port.uartclk, 1 << 16, 1 << 16, &num, &denom); tdiv64 = sport->port.uartclk; tdiv64 *= num; do_div(tdiv64, denom * 16 * div); tty_termios_encode_baud_rate(termios, (speed_t)tdiv64, (speed_t)tdiv64); num -= 1; denom -= 1; ufcr = imx_uart_readl(sport, UFCR); ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div); imx_uart_writel(sport, ufcr, UFCR); /* * Two registers below should always be written both and in this * particular order. One consequence is that we need to check if any of * them changes and then update both. We do need the check for change * as even writing the same values seem to "restart" * transmission/receiving logic in the hardware, that leads to data * breakage even when rate doesn't in fact change. E.g., user switches * RTS/CTS handshake and suddenly gets broken bytes. */ old_ubir = imx_uart_readl(sport, UBIR); old_ubmr = imx_uart_readl(sport, UBMR); if (old_ubir != num || old_ubmr != denom) { imx_uart_writel(sport, num, UBIR); imx_uart_writel(sport, denom, UBMR); } if (!imx_uart_is_imx1(sport)) imx_uart_writel(sport, sport->port.uartclk / div / 1000, IMX21_ONEMS); imx_uart_writel(sport, ucr2, UCR2); if (UART_ENABLE_MS(&sport->port, termios->c_cflag)) imx_uart_enable_ms(&sport->port); uart_port_unlock_irqrestore(&sport->port, flags); } static const char *imx_uart_type(struct uart_port *port) { return port->type == PORT_IMX ? "IMX" : NULL; } /* * Configure/autoconfigure the port. */ static void imx_uart_config_port(struct uart_port *port, int flags) { if (flags & UART_CONFIG_TYPE) port->type = PORT_IMX; } /* * Verify the new serial_struct (for TIOCSSERIAL). * The only change we allow are to the flags and type, and * even then only between PORT_IMX and PORT_UNKNOWN */ static int imx_uart_verify_port(struct uart_port *port, struct serial_struct *ser) { int ret = 0; if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX) ret = -EINVAL; if (port->irq != ser->irq) ret = -EINVAL; if (ser->io_type != UPIO_MEM) ret = -EINVAL; if (port->uartclk / 16 != ser->baud_base) ret = -EINVAL; if (port->mapbase != (unsigned long)ser->iomem_base) ret = -EINVAL; if (port->iobase != ser->port) ret = -EINVAL; if (ser->hub6 != 0) ret = -EINVAL; return ret; } #if defined(CONFIG_CONSOLE_POLL) static int imx_uart_poll_init(struct uart_port *port) { struct imx_port *sport = (struct imx_port *)port; unsigned long flags; u32 ucr1, ucr2; int retval; retval = clk_prepare_enable(sport->clk_ipg); if (retval) return retval; retval = clk_prepare_enable(sport->clk_per); if (retval) clk_disable_unprepare(sport->clk_ipg); imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT); uart_port_lock_irqsave(&sport->port, &flags); /* * Be careful about the order of enabling bits here. First enable the * receiver (UARTEN + RXEN) and only then the corresponding irqs. * This prevents that a character that already sits in the RX fifo is * triggering an irq but the try to fetch it from there results in an * exception because UARTEN or RXEN is still off. */ ucr1 = imx_uart_readl(sport, UCR1); ucr2 = imx_uart_readl(sport, UCR2); if (imx_uart_is_imx1(sport)) ucr1 |= IMX1_UCR1_UARTCLKEN; ucr1 |= UCR1_UARTEN; ucr1 &= ~(UCR1_TRDYEN | UCR1_RTSDEN | UCR1_RRDYEN); ucr2 |= UCR2_RXEN | UCR2_TXEN; ucr2 &= ~UCR2_ATEN; imx_uart_writel(sport, ucr1, UCR1); imx_uart_writel(sport, ucr2, UCR2); /* now enable irqs */ imx_uart_writel(sport, ucr1 | UCR1_RRDYEN, UCR1); imx_uart_writel(sport, ucr2 | UCR2_ATEN, UCR2); uart_port_unlock_irqrestore(&sport->port, flags); return 0; } static int imx_uart_poll_get_char(struct uart_port *port) { struct imx_port *sport = (struct imx_port *)port; if (!(imx_uart_readl(sport, USR2) & USR2_RDR)) return NO_POLL_CHAR; return imx_uart_readl(sport, URXD0) & URXD_RX_DATA; } static void imx_uart_poll_put_char(struct uart_port *port, unsigned char c) { struct imx_port *sport = (struct imx_port *)port; unsigned int status; /* drain */ do { status = imx_uart_readl(sport, USR1); } while (~status & USR1_TRDY); /* write */ imx_uart_writel(sport, c, URTX0); /* flush */ do { status = imx_uart_readl(sport, USR2); } while (~status & USR2_TXDC); } #endif /* called with port.lock taken and irqs off or from .probe without locking */ static int imx_uart_rs485_config(struct uart_port *port, struct ktermios *termios, struct serial_rs485 *rs485conf) { struct imx_port *sport = (struct imx_port *)port; u32 ucr2, ufcr; if (rs485conf->flags & SER_RS485_ENABLED) { /* Enable receiver if low-active RTS signal is requested */ if (sport->have_rtscts && !sport->have_rtsgpio && !(rs485conf->flags & SER_RS485_RTS_ON_SEND)) rs485conf->flags |= SER_RS485_RX_DURING_TX; /* disable transmitter */ ucr2 = imx_uart_readl(sport, UCR2); if (rs485conf->flags & SER_RS485_RTS_AFTER_SEND) imx_uart_rts_active(sport, &ucr2); else imx_uart_rts_inactive(sport, &ucr2); imx_uart_writel(sport, ucr2, UCR2); } /* Make sure Rx is enabled in case Tx is active with Rx disabled */ if (!(rs485conf->flags & SER_RS485_ENABLED) || rs485conf->flags & SER_RS485_RX_DURING_TX) { /* If the receiver trigger is 0, set it to a default value */ ufcr = imx_uart_readl(sport, UFCR); if ((ufcr & UFCR_RXTL_MASK) == 0) imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT); imx_uart_start_rx(port); } return 0; } static const struct uart_ops imx_uart_pops = { .tx_empty = imx_uart_tx_empty, .set_mctrl = imx_uart_set_mctrl, .get_mctrl = imx_uart_get_mctrl, .stop_tx = imx_uart_stop_tx, .start_tx = imx_uart_start_tx, .stop_rx = imx_uart_stop_rx, .enable_ms = imx_uart_enable_ms, .break_ctl = imx_uart_break_ctl, .startup = imx_uart_startup, .shutdown = imx_uart_shutdown, .flush_buffer = imx_uart_flush_buffer, .set_termios = imx_uart_set_termios, .type = imx_uart_type, .config_port = imx_uart_config_port, .verify_port = imx_uart_verify_port, #if defined(CONFIG_CONSOLE_POLL) .poll_init = imx_uart_poll_init, .poll_get_char = imx_uart_poll_get_char, .poll_put_char = imx_uart_poll_put_char, #endif }; static struct imx_port *imx_uart_ports[UART_NR]; #if IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE) static void imx_uart_console_putchar(struct uart_port *port, unsigned char ch) { struct imx_port *sport = (struct imx_port *)port; while (imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL) barrier(); imx_uart_writel(sport, ch, URTX0); } /* * Interrupts are disabled on entering */ static void imx_uart_console_write(struct console *co, const char *s, unsigned int count) { struct imx_port *sport = imx_uart_ports[co->index]; struct imx_port_ucrs old_ucr; unsigned long flags; unsigned int ucr1, usr2; int locked = 1; if (sport->port.sysrq) locked = 0; else if (oops_in_progress) locked = uart_port_trylock_irqsave(&sport->port, &flags); else uart_port_lock_irqsave(&sport->port, &flags); /* * First, save UCR1/2/3 and then disable interrupts */ imx_uart_ucrs_save(sport, &old_ucr); ucr1 = old_ucr.ucr1; if (imx_uart_is_imx1(sport)) ucr1 |= IMX1_UCR1_UARTCLKEN; ucr1 |= UCR1_UARTEN; ucr1 &= ~(UCR1_TRDYEN | UCR1_RRDYEN | UCR1_RTSDEN); imx_uart_writel(sport, ucr1, UCR1); imx_uart_writel(sport, old_ucr.ucr2 | UCR2_TXEN, UCR2); uart_console_write(&sport->port, s, count, imx_uart_console_putchar); /* * Finally, wait for transmitter to become empty * and restore UCR1/2/3 */ read_poll_timeout_atomic(imx_uart_readl, usr2, usr2 & USR2_TXDC, 0, USEC_PER_SEC, false, sport, USR2); imx_uart_ucrs_restore(sport, &old_ucr); if (locked) uart_port_unlock_irqrestore(&sport->port, flags); } /* * If the port was already initialised (eg, by a boot loader), * try to determine the current setup. */ static void imx_uart_console_get_options(struct imx_port *sport, int *baud, int *parity, int *bits) { if (imx_uart_readl(sport, UCR1) & UCR1_UARTEN) { /* ok, the port was enabled */ unsigned int ucr2, ubir, ubmr, uartclk; unsigned int baud_raw; unsigned int ucfr_rfdiv; ucr2 = imx_uart_readl(sport, UCR2); *parity = 'n'; if (ucr2 & UCR2_PREN) { if (ucr2 & UCR2_PROE) *parity = 'o'; else *parity = 'e'; } if (ucr2 & UCR2_WS) *bits = 8; else *bits = 7; ubir = imx_uart_readl(sport, UBIR) & 0xffff; ubmr = imx_uart_readl(sport, UBMR) & 0xffff; ucfr_rfdiv = (imx_uart_readl(sport, UFCR) & UFCR_RFDIV) >> 7; if (ucfr_rfdiv == 6) ucfr_rfdiv = 7; else ucfr_rfdiv = 6 - ucfr_rfdiv; uartclk = clk_get_rate(sport->clk_per); uartclk /= ucfr_rfdiv; { /* * The next code provides exact computation of * baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1)) * without need of float support or long long division, * which would be required to prevent 32bit arithmetic overflow */ unsigned int mul = ubir + 1; unsigned int div = 16 * (ubmr + 1); unsigned int rem = uartclk % div; baud_raw = (uartclk / div) * mul; baud_raw += (rem * mul + div / 2) / div; *baud = (baud_raw + 50) / 100 * 100; } if (*baud != baud_raw) dev_info(sport->port.dev, "Console IMX rounded baud rate from %d to %d\n", baud_raw, *baud); } } static int imx_uart_console_setup(struct console *co, char *options) { struct imx_port *sport; int baud = 9600; int bits = 8; int parity = 'n'; int flow = 'n'; int retval; /* * Check whether an invalid uart number has been specified, and * if so, search for the first available port that does have * console support. */ if (co->index == -1 || co->index >= ARRAY_SIZE(imx_uart_ports)) co->index = 0; sport = imx_uart_ports[co->index]; if (sport == NULL) return -ENODEV; /* For setting the registers, we only need to enable the ipg clock. */ retval = clk_prepare_enable(sport->clk_ipg); if (retval) goto error_console; if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); else imx_uart_console_get_options(sport, &baud, &parity, &bits); imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT); retval = uart_set_options(&sport->port, co, baud, parity, bits, flow); if (retval) { clk_disable_unprepare(sport->clk_ipg); goto error_console; } retval = clk_prepare_enable(sport->clk_per); if (retval) clk_disable_unprepare(sport->clk_ipg); error_console: return retval; } static int imx_uart_console_exit(struct console *co) { struct imx_port *sport = imx_uart_ports[co->index]; clk_disable_unprepare(sport->clk_per); clk_disable_unprepare(sport->clk_ipg); return 0; } static struct uart_driver imx_uart_uart_driver; static struct console imx_uart_console = { .name = DEV_NAME, .write = imx_uart_console_write, .device = uart_console_device, .setup = imx_uart_console_setup, .exit = imx_uart_console_exit, .flags = CON_PRINTBUFFER, .index = -1, .data = &imx_uart_uart_driver, }; #define IMX_CONSOLE &imx_uart_console #else #define IMX_CONSOLE NULL #endif static struct uart_driver imx_uart_uart_driver = { .owner = THIS_MODULE, .driver_name = DRIVER_NAME, .dev_name = DEV_NAME, .major = SERIAL_IMX_MAJOR, .minor = MINOR_START, .nr = ARRAY_SIZE(imx_uart_ports), .cons = IMX_CONSOLE, }; static enum hrtimer_restart imx_trigger_start_tx(struct hrtimer *t) { struct imx_port *sport = container_of(t, struct imx_port, trigger_start_tx); unsigned long flags; uart_port_lock_irqsave(&sport->port, &flags); if (sport->tx_state == WAIT_AFTER_RTS) imx_uart_start_tx(&sport->port); uart_port_unlock_irqrestore(&sport->port, flags); return HRTIMER_NORESTART; } static enum hrtimer_restart imx_trigger_stop_tx(struct hrtimer *t) { struct imx_port *sport = container_of(t, struct imx_port, trigger_stop_tx); unsigned long flags; uart_port_lock_irqsave(&sport->port, &flags); if (sport->tx_state == WAIT_AFTER_SEND) imx_uart_stop_tx(&sport->port); uart_port_unlock_irqrestore(&sport->port, flags); return HRTIMER_NORESTART; } static const struct serial_rs485 imx_rs485_supported = { .flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND | SER_RS485_RX_DURING_TX, .delay_rts_before_send = 1, .delay_rts_after_send = 1, }; /* Default RX DMA buffer configuration */ #define RX_DMA_PERIODS 16 #define RX_DMA_PERIOD_LEN (PAGE_SIZE / 4) static int imx_uart_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; struct imx_port *sport; void __iomem *base; u32 dma_buf_conf[2]; int ret = 0; u32 ucr1, ucr2, uts; struct resource *res; int txirq, rxirq, rtsirq; sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL); if (!sport) return -ENOMEM; sport->devdata = of_device_get_match_data(&pdev->dev); ret = of_alias_get_id(np, "serial"); if (ret < 0) { dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret); return ret; } sport->port.line = ret; sport->have_rtscts = of_property_read_bool(np, "uart-has-rtscts") || of_property_read_bool(np, "fsl,uart-has-rtscts"); /* deprecated */ sport->dte_mode = of_property_read_bool(np, "fsl,dte-mode"); sport->have_rtsgpio = of_property_present(np, "rts-gpios"); sport->inverted_tx = of_property_read_bool(np, "fsl,inverted-tx"); sport->inverted_rx = of_property_read_bool(np, "fsl,inverted-rx"); if (!of_property_read_u32_array(np, "fsl,dma-info", dma_buf_conf, 2)) { sport->rx_period_length = dma_buf_conf[0]; sport->rx_periods = dma_buf_conf[1]; } else { sport->rx_period_length = RX_DMA_PERIOD_LEN; sport->rx_periods = RX_DMA_PERIODS; } if (sport->port.line >= ARRAY_SIZE(imx_uart_ports)) { dev_err(&pdev->dev, "serial%d out of range\n", sport->port.line); return -EINVAL; } base = devm_platform_get_and_ioremap_resource(pdev, 0, &res); if (IS_ERR(base)) return PTR_ERR(base); rxirq = platform_get_irq(pdev, 0); if (rxirq < 0) return rxirq; txirq = platform_get_irq_optional(pdev, 1); rtsirq = platform_get_irq_optional(pdev, 2); sport->port.dev = &pdev->dev; sport->port.mapbase = res->start; sport->port.membase = base; sport->port.type = PORT_IMX; sport->port.iotype = UPIO_MEM; sport->port.irq = rxirq; sport->port.fifosize = 32; sport->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE); sport->port.ops = &imx_uart_pops; sport->port.rs485_config = imx_uart_rs485_config; /* RTS is required to control the RS485 transmitter */ if (sport->have_rtscts || sport->have_rtsgpio) sport->port.rs485_supported = imx_rs485_supported; sport->port.flags = UPF_BOOT_AUTOCONF; timer_setup(&sport->timer, imx_uart_timeout, 0); sport->gpios = mctrl_gpio_init(&sport->port, 0); if (IS_ERR(sport->gpios)) return PTR_ERR(sport->gpios); sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg"); if (IS_ERR(sport->clk_ipg)) { ret = PTR_ERR(sport->clk_ipg); dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret); return ret; } sport->clk_per = devm_clk_get(&pdev->dev, "per"); if (IS_ERR(sport->clk_per)) { ret = PTR_ERR(sport->clk_per); dev_err(&pdev->dev, "failed to get per clk: %d\n", ret); return ret; } sport->port.uartclk = clk_get_rate(sport->clk_per); /* For register access, we only need to enable the ipg clock. */ ret = clk_prepare_enable(sport->clk_ipg); if (ret) { dev_err(&pdev->dev, "failed to enable ipg clk: %d\n", ret); return ret; } ret = uart_get_rs485_mode(&sport->port); if (ret) goto err_clk; /* * If using the i.MX UART RTS/CTS control then the RTS (CTS_B) * signal cannot be set low during transmission in case the * receiver is off (limitation of the i.MX UART IP). */ if (sport->port.rs485.flags & SER_RS485_ENABLED && sport->have_rtscts && !sport->have_rtsgpio && (!(sport->port.rs485.flags & SER_RS485_RTS_ON_SEND) && !(sport->port.rs485.flags & SER_RS485_RX_DURING_TX))) dev_err(&pdev->dev, "low-active RTS not possible when receiver is off, enabling receiver\n"); /* Disable interrupts before requesting them */ ucr1 = imx_uart_readl(sport, UCR1); ucr1 &= ~(UCR1_ADEN | UCR1_TRDYEN | UCR1_IDEN | UCR1_RRDYEN | UCR1_RTSDEN); imx_uart_writel(sport, ucr1, UCR1); /* Disable Ageing Timer interrupt */ ucr2 = imx_uart_readl(sport, UCR2); ucr2 &= ~UCR2_ATEN; imx_uart_writel(sport, ucr2, UCR2); /* * In case RS485 is enabled without GPIO RTS control, the UART IP * is used to control CTS signal. Keep both the UART and Receiver * enabled, otherwise the UART IP pulls CTS signal always HIGH no * matter how the UCR2 CTSC and CTS bits are set. To prevent any * data from being fed into the RX FIFO, enable loopback mode in * UTS register, which disconnects the RX path from external RXD * pin and connects it to the Transceiver, which is disabled, so * no data can be fed to the RX FIFO that way. */ if (sport->port.rs485.flags & SER_RS485_ENABLED && sport->have_rtscts && !sport->have_rtsgpio) { uts = imx_uart_readl(sport, imx_uart_uts_reg(sport)); uts |= UTS_LOOP; imx_uart_writel(sport, uts, imx_uart_uts_reg(sport)); ucr1 = imx_uart_readl(sport, UCR1); ucr1 |= UCR1_UARTEN; imx_uart_writel(sport, ucr1, UCR1); ucr2 = imx_uart_readl(sport, UCR2); ucr2 |= UCR2_RXEN; imx_uart_writel(sport, ucr2, UCR2); } if (!imx_uart_is_imx1(sport) && sport->dte_mode) { /* * The DCEDTE bit changes the direction of DSR, DCD, DTR and RI * and influences if UCR3_RI and UCR3_DCD changes the level of RI * and DCD (when they are outputs) or enables the respective * irqs. So set this bit early, i.e. before requesting irqs. */ u32 ufcr = imx_uart_readl(sport, UFCR); if (!(ufcr & UFCR_DCEDTE)) imx_uart_writel(sport, ufcr | UFCR_DCEDTE, UFCR); /* * Disable UCR3_RI and UCR3_DCD irqs. They are also not * enabled later because they cannot be cleared * (confirmed on i.MX25) which makes them unusable. */ imx_uart_writel(sport, IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP | UCR3_DSR, UCR3); } else { u32 ucr3 = UCR3_DSR; u32 ufcr = imx_uart_readl(sport, UFCR); if (ufcr & UFCR_DCEDTE) imx_uart_writel(sport, ufcr & ~UFCR_DCEDTE, UFCR); if (!imx_uart_is_imx1(sport)) ucr3 |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP; imx_uart_writel(sport, ucr3, UCR3); } hrtimer_init(&sport->trigger_start_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL); hrtimer_init(&sport->trigger_stop_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL); sport->trigger_start_tx.function = imx_trigger_start_tx; sport->trigger_stop_tx.function = imx_trigger_stop_tx; /* * Allocate the IRQ(s) i.MX1 has three interrupts whereas later * chips only have one interrupt. */ if (txirq > 0) { ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_rxint, 0, dev_name(&pdev->dev), sport); if (ret) { dev_err(&pdev->dev, "failed to request rx irq: %d\n", ret); goto err_clk; } ret = devm_request_irq(&pdev->dev, txirq, imx_uart_txint, 0, dev_name(&pdev->dev), sport); if (ret) { dev_err(&pdev->dev, "failed to request tx irq: %d\n", ret); goto err_clk; } ret = devm_request_irq(&pdev->dev, rtsirq, imx_uart_rtsint, 0, dev_name(&pdev->dev), sport); if (ret) { dev_err(&pdev->dev, "failed to request rts irq: %d\n", ret); goto err_clk; } } else { ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_int, 0, dev_name(&pdev->dev), sport); if (ret) { dev_err(&pdev->dev, "failed to request irq: %d\n", ret); goto err_clk; } } imx_uart_ports[sport->port.line] = sport; platform_set_drvdata(pdev, sport); ret = uart_add_one_port(&imx_uart_uart_driver, &sport->port); err_clk: clk_disable_unprepare(sport->clk_ipg); return ret; } static void imx_uart_remove(struct platform_device *pdev) { struct imx_port *sport = platform_get_drvdata(pdev); uart_remove_one_port(&imx_uart_uart_driver, &sport->port); } static void imx_uart_restore_context(struct imx_port *sport) { unsigned long flags; uart_port_lock_irqsave(&sport->port, &flags); if (!sport->context_saved) { uart_port_unlock_irqrestore(&sport->port, flags); return; } imx_uart_writel(sport, sport->saved_reg[4], UFCR); imx_uart_writel(sport, sport->saved_reg[5], UESC); imx_uart_writel(sport, sport->saved_reg[6], UTIM); imx_uart_writel(sport, sport->saved_reg[7], UBIR); imx_uart_writel(sport, sport->saved_reg[8], UBMR); imx_uart_writel(sport, sport->saved_reg[9], IMX21_UTS); imx_uart_writel(sport, sport->saved_reg[0], UCR1); imx_uart_writel(sport, sport->saved_reg[1] | UCR2_SRST, UCR2); imx_uart_writel(sport, sport->saved_reg[2], UCR3); imx_uart_writel(sport, sport->saved_reg[3], UCR4); sport->context_saved = false; uart_port_unlock_irqrestore(&sport->port, flags); } static void imx_uart_save_context(struct imx_port *sport) { unsigned long flags; /* Save necessary regs */ uart_port_lock_irqsave(&sport->port, &flags); sport->saved_reg[0] = imx_uart_readl(sport, UCR1); sport->saved_reg[1] = imx_uart_readl(sport, UCR2); sport->saved_reg[2] = imx_uart_readl(sport, UCR3); sport->saved_reg[3] = imx_uart_readl(sport, UCR4); sport->saved_reg[4] = imx_uart_readl(sport, UFCR); sport->saved_reg[5] = imx_uart_readl(sport, UESC); sport->saved_reg[6] = imx_uart_readl(sport, UTIM); sport->saved_reg[7] = imx_uart_readl(sport, UBIR); sport->saved_reg[8] = imx_uart_readl(sport, UBMR); sport->saved_reg[9] = imx_uart_readl(sport, IMX21_UTS); sport->context_saved = true; uart_port_unlock_irqrestore(&sport->port, flags); } static void imx_uart_enable_wakeup(struct imx_port *sport, bool on) { u32 ucr3; ucr3 = imx_uart_readl(sport, UCR3); if (on) { imx_uart_writel(sport, USR1_AWAKE, USR1); ucr3 |= UCR3_AWAKEN; } else { ucr3 &= ~UCR3_AWAKEN; } imx_uart_writel(sport, ucr3, UCR3); if (sport->have_rtscts) { u32 ucr1 = imx_uart_readl(sport, UCR1); if (on) { imx_uart_writel(sport, USR1_RTSD, USR1); ucr1 |= UCR1_RTSDEN; } else { ucr1 &= ~UCR1_RTSDEN; } imx_uart_writel(sport, ucr1, UCR1); } } static int imx_uart_suspend_noirq(struct device *dev) { struct imx_port *sport = dev_get_drvdata(dev); imx_uart_save_context(sport); clk_disable(sport->clk_ipg); pinctrl_pm_select_sleep_state(dev); return 0; } static int imx_uart_resume_noirq(struct device *dev) { struct imx_port *sport = dev_get_drvdata(dev); int ret; pinctrl_pm_select_default_state(dev); ret = clk_enable(sport->clk_ipg); if (ret) return ret; imx_uart_restore_context(sport); return 0; } static int imx_uart_suspend(struct device *dev) { struct imx_port *sport = dev_get_drvdata(dev); int ret; uart_suspend_port(&imx_uart_uart_driver, &sport->port); disable_irq(sport->port.irq); ret = clk_prepare_enable(sport->clk_ipg); if (ret) return ret; /* enable wakeup from i.MX UART */ imx_uart_enable_wakeup(sport, true); return 0; } static int imx_uart_resume(struct device *dev) { struct imx_port *sport = dev_get_drvdata(dev); /* disable wakeup from i.MX UART */ imx_uart_enable_wakeup(sport, false); uart_resume_port(&imx_uart_uart_driver, &sport->port); enable_irq(sport->port.irq); clk_disable_unprepare(sport->clk_ipg); return 0; } static int imx_uart_freeze(struct device *dev) { struct imx_port *sport = dev_get_drvdata(dev); uart_suspend_port(&imx_uart_uart_driver, &sport->port); return clk_prepare_enable(sport->clk_ipg); } static int imx_uart_thaw(struct device *dev) { struct imx_port *sport = dev_get_drvdata(dev); uart_resume_port(&imx_uart_uart_driver, &sport->port); clk_disable_unprepare(sport->clk_ipg); return 0; } static const struct dev_pm_ops imx_uart_pm_ops = { .suspend_noirq = imx_uart_suspend_noirq, .resume_noirq = imx_uart_resume_noirq, .freeze_noirq = imx_uart_suspend_noirq, .thaw_noirq = imx_uart_resume_noirq, .restore_noirq = imx_uart_resume_noirq, .suspend = imx_uart_suspend, .resume = imx_uart_resume, .freeze = imx_uart_freeze, .thaw = imx_uart_thaw, .restore = imx_uart_thaw, }; static struct platform_driver imx_uart_platform_driver = { .probe = imx_uart_probe, .remove_new = imx_uart_remove, .driver = { .name = "imx-uart", .of_match_table = imx_uart_dt_ids, .pm = &imx_uart_pm_ops, }, }; static int __init imx_uart_init(void) { int ret = uart_register_driver(&imx_uart_uart_driver); if (ret) return ret; ret = platform_driver_register(&imx_uart_platform_driver); if (ret != 0) uart_unregister_driver(&imx_uart_uart_driver); return ret; } static void __exit imx_uart_exit(void) { platform_driver_unregister(&imx_uart_platform_driver); uart_unregister_driver(&imx_uart_uart_driver); } module_init(imx_uart_init); module_exit(imx_uart_exit); MODULE_AUTHOR("Sascha Hauer"); MODULE_DESCRIPTION("IMX generic serial port driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:imx-uart");
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