// 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 <[email protected]> * 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 … #define URTX0 … #define UCR1 … #define UCR2 … #define UCR3 … #define UCR4 … #define UFCR … #define USR1 … #define USR2 … #define UESC … #define UTIM … #define UBIR … #define UBMR … #define UBRC … #define IMX21_ONEMS … #define IMX1_UTS … #define IMX21_UTS … /* UART Control Register Bit Fields.*/ #define URXD_DUMMY_READ … #define URXD_CHARRDY … #define URXD_ERR … #define URXD_OVRRUN … #define URXD_FRMERR … #define URXD_BRK … #define URXD_PRERR … #define URXD_RX_DATA … #define UCR1_ADEN … #define UCR1_ADBR … #define UCR1_TRDYEN … #define UCR1_IDEN … #define UCR1_ICD_REG(x) … #define UCR1_RRDYEN … #define UCR1_RXDMAEN … #define UCR1_IREN … #define UCR1_TXMPTYEN … #define UCR1_RTSDEN … #define UCR1_SNDBRK … #define UCR1_TXDMAEN … #define IMX1_UCR1_UARTCLKEN … #define UCR1_ATDMAEN … #define UCR1_DOZE … #define UCR1_UARTEN … #define UCR2_ESCI … #define UCR2_IRTS … #define UCR2_CTSC … #define UCR2_CTS … #define UCR2_ESCEN … #define UCR2_PREN … #define UCR2_PROE … #define UCR2_STPB … #define UCR2_WS … #define UCR2_RTSEN … #define UCR2_ATEN … #define UCR2_TXEN … #define UCR2_RXEN … #define UCR2_SRST … #define UCR3_DTREN … #define UCR3_PARERREN … #define UCR3_FRAERREN … #define UCR3_DSR … #define UCR3_DCD … #define UCR3_RI … #define UCR3_ADNIMP … #define UCR3_RXDSEN … #define UCR3_AIRINTEN … #define UCR3_AWAKEN … #define UCR3_DTRDEN … #define IMX21_UCR3_RXDMUXSEL … #define UCR3_INVT … #define UCR3_BPEN … #define UCR4_CTSTL_SHF … #define UCR4_CTSTL_MASK … #define UCR4_INVR … #define UCR4_ENIRI … #define UCR4_WKEN … #define UCR4_REF16 … #define UCR4_IDDMAEN … #define UCR4_IRSC … #define UCR4_TCEN … #define UCR4_BKEN … #define UCR4_OREN … #define UCR4_DREN … #define UFCR_RXTL_SHF … #define UFCR_RXTL_MASK … #define UFCR_DCEDTE … #define UFCR_RFDIV … #define UFCR_RFDIV_REG(x) … #define UFCR_TXTL_SHF … #define USR1_PARITYERR … #define USR1_RTSS … #define USR1_TRDY … #define USR1_RTSD … #define USR1_ESCF … #define USR1_FRAMERR … #define USR1_RRDY … #define USR1_AGTIM … #define USR1_DTRD … #define USR1_RXDS … #define USR1_AIRINT … #define USR1_AWAKE … #define USR2_ADET … #define USR2_TXFE … #define USR2_DTRF … #define USR2_IDLE … #define USR2_RIDELT … #define USR2_RIIN … #define USR2_IRINT … #define USR2_WAKE … #define USR2_DCDIN … #define USR2_RTSF … #define USR2_TXDC … #define USR2_BRCD … #define USR2_ORE … #define USR2_RDR … #define UTS_FRCPERR … #define UTS_LOOP … #define UTS_TXEMPTY … #define UTS_RXEMPTY … #define UTS_TXFULL … #define UTS_RXFULL … #define UTS_SOFTRST … /* We've been assigned a range on the "Low-density serial ports" major */ #define SERIAL_IMX_MAJOR … #define MINOR_START … #define DEV_NAME … /* * 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 … #define DRIVER_NAME … #define UART_NR … /* i.MX21 type uart runs on all i.mx except i.MX1 and i.MX6q */ enum imx_uart_type { … }; /* device type dependent stuff */ struct imx_uart_data { … }; enum imx_tx_state { … }; struct imx_port { … }; struct imx_port_ucrs { … }; static const struct imx_uart_data imx_uart_imx1_devdata = …; static const struct imx_uart_data imx_uart_imx21_devdata = …; static const struct of_device_id imx_uart_dt_ids[] = …; MODULE_DEVICE_TABLE(of, imx_uart_dt_ids); static inline struct imx_port *to_imx_port(struct uart_port *port) { … } static inline void imx_uart_writel(struct imx_port *sport, u32 val, u32 offset) { … } static inline u32 imx_uart_readl(struct imx_port *sport, u32 offset) { … } static inline unsigned imx_uart_uts_reg(struct imx_port *sport) { … } static inline int imx_uart_is_imx1(struct imx_port *sport) { … } /* * 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) { … } static void imx_uart_ucrs_restore(struct imx_port *sport, struct imx_port_ucrs *ucr) { … } #endif /* called with port.lock taken and irqs caller dependent */ static void imx_uart_rts_active(struct imx_port *sport, u32 *ucr2) { … } /* called with port.lock taken and irqs caller dependent */ static void imx_uart_rts_inactive(struct imx_port *sport, u32 *ucr2) { … } static void start_hrtimer_ms(struct hrtimer *hrt, unsigned long msec) { … } /* called with port.lock taken and irqs off */ static void imx_uart_soft_reset(struct imx_port *sport) { … } static void imx_uart_disable_loopback_rs485(struct imx_port *sport) { … } /* called with port.lock taken and irqs off */ static void imx_uart_start_rx(struct uart_port *port) { … } /* called with port.lock taken and irqs off */ static void imx_uart_stop_tx(struct uart_port *port) { … } static void imx_uart_stop_rx_with_loopback_ctrl(struct uart_port *port, bool loopback) { … } /* called with port.lock taken and irqs off */ static void imx_uart_stop_rx(struct uart_port *port) { … } /* called with port.lock taken and irqs off */ static void imx_uart_enable_ms(struct uart_port *port) { … } 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) { … } static void imx_uart_dma_tx_callback(void *data) { … } /* called with port.lock taken and irqs off */ static void imx_uart_dma_tx(struct imx_port *sport) { … } /* called with port.lock taken and irqs off */ static void imx_uart_start_tx(struct uart_port *port) { … } static irqreturn_t __imx_uart_rtsint(int irq, void *dev_id) { … } static irqreturn_t imx_uart_rtsint(int irq, void *dev_id) { … } static irqreturn_t imx_uart_txint(int irq, void *dev_id) { … } /* 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) { … } static irqreturn_t __imx_uart_rxint(int irq, void *dev_id) { … } static irqreturn_t imx_uart_rxint(int irq, void *dev_id) { … } 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) { … } /* * Handle any change of modem status signal since we were last called. */ static void imx_uart_mctrl_check(struct imx_port *sport) { … } static irqreturn_t imx_uart_int(int irq, void *dev_id) { … } /* * Return TIOCSER_TEMT when transmitter is not busy. */ static unsigned int imx_uart_tx_empty(struct uart_port *port) { … } /* called with port.lock taken and irqs off */ static unsigned int imx_uart_get_mctrl(struct uart_port *port) { … } /* called with port.lock taken and irqs off */ static void imx_uart_set_mctrl(struct uart_port *port, unsigned int mctrl) { … } /* * Interrupts always disabled. */ static void imx_uart_break_ctl(struct uart_port *port, int break_state) { … } /* * This is our per-port timeout handler, for checking the * modem status signals. */ static void imx_uart_timeout(struct timer_list *t) { … } /* * 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) { … } static int imx_uart_start_rx_dma(struct imx_port *sport) { … } static void imx_uart_clear_rx_errors(struct imx_port *sport) { … } #define TXTL_DEFAULT … #define RXTL_DEFAULT … #define TXTL_DMA … #define RXTL_DMA … static void imx_uart_setup_ufcr(struct imx_port *sport, unsigned char txwl, unsigned char rxwl) { … } static void imx_uart_dma_exit(struct imx_port *sport) { … } static int imx_uart_dma_init(struct imx_port *sport) { … } static void imx_uart_enable_dma(struct imx_port *sport) { … } static void imx_uart_disable_dma(struct imx_port *sport) { … } /* half the RX buffer size */ #define CTSTL … static int imx_uart_startup(struct uart_port *port) { … } static void imx_uart_shutdown(struct uart_port *port) { … } /* called with port.lock taken and irqs off */ static void imx_uart_flush_buffer(struct uart_port *port) { … } static void imx_uart_set_termios(struct uart_port *port, struct ktermios *termios, const struct ktermios *old) { … } static const char *imx_uart_type(struct uart_port *port) { … } /* * Configure/autoconfigure the port. */ static void imx_uart_config_port(struct uart_port *port, int flags) { … } /* * 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) { … } #if defined(CONFIG_CONSOLE_POLL) static int imx_uart_poll_init(struct uart_port *port) { … } static int imx_uart_poll_get_char(struct uart_port *port) { … } static void imx_uart_poll_put_char(struct uart_port *port, unsigned char c) { … } #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) { … } static const struct uart_ops imx_uart_pops = …; 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) { … } /* * Interrupts are disabled on entering */ static void imx_uart_console_write(struct console *co, const char *s, unsigned int count) { … } /* * 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) { … } static int imx_uart_console_setup(struct console *co, char *options) { … } static int imx_uart_console_exit(struct console *co) { … } static struct uart_driver imx_uart_uart_driver; static struct console imx_uart_console = …; #define IMX_CONSOLE … #else #define IMX_CONSOLE … #endif static struct uart_driver imx_uart_uart_driver = …; static enum hrtimer_restart imx_trigger_start_tx(struct hrtimer *t) { … } static enum hrtimer_restart imx_trigger_stop_tx(struct hrtimer *t) { … } static const struct serial_rs485 imx_rs485_supported = …; /* Default RX DMA buffer configuration */ #define RX_DMA_PERIODS … #define RX_DMA_PERIOD_LEN … static int imx_uart_probe(struct platform_device *pdev) { … } static void imx_uart_remove(struct platform_device *pdev) { … } static void imx_uart_restore_context(struct imx_port *sport) { … } static void imx_uart_save_context(struct imx_port *sport) { … } static void imx_uart_enable_wakeup(struct imx_port *sport, bool on) { … } static int imx_uart_suspend_noirq(struct device *dev) { … } static int imx_uart_resume_noirq(struct device *dev) { … } static int imx_uart_suspend(struct device *dev) { … } static int imx_uart_resume(struct device *dev) { … } static int imx_uart_freeze(struct device *dev) { … } static int imx_uart_thaw(struct device *dev) { … } static const struct dev_pm_ops imx_uart_pm_ops = …; static struct platform_driver imx_uart_platform_driver = …; static int __init imx_uart_init(void) { … } static void __exit imx_uart_exit(void) { … } module_init(…) …; module_exit(imx_uart_exit); MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …; MODULE_ALIAS(…) …;
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