diff options
Diffstat (limited to 'drivers/tty/serial/sccnxp.c')
| -rw-r--r-- | drivers/tty/serial/sccnxp.c | 121 |
1 files changed, 77 insertions, 44 deletions
diff --git a/drivers/tty/serial/sccnxp.c b/drivers/tty/serial/sccnxp.c index cdd2f942317c..4ceca11ce600 100644 --- a/drivers/tty/serial/sccnxp.c +++ b/drivers/tty/serial/sccnxp.c @@ -1,23 +1,17 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * NXP (Philips) SCC+++(SCN+++) serial driver * * Copyright (C) 2012 Alexander Shiyan <shc_work@mail.ru> * * Based on sc26xx.c, by Thomas Bogendörfer (tsbogend@alpha.franken.de) - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. */ -#if defined(CONFIG_SERIAL_SCCNXP_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) -#define SUPPORT_SYSRQ -#endif - #include <linux/clk.h> +#include <linux/delay.h> #include <linux/err.h> #include <linux/module.h> +#include <linux/mod_devicetable.h> #include <linux/device.h> #include <linux/console.h> #include <linux/serial_core.h> @@ -50,7 +44,6 @@ # define MR2_STOP1 (7 << 0) # define MR2_STOP2 (0xf << 0) #define SCCNXP_SR_REG (0x01) -#define SCCNXP_CSR_REG SCCNXP_SR_REG # define SR_RXRDY (1 << 0) # define SR_FULL (1 << 1) # define SR_TXRDY (1 << 2) @@ -59,6 +52,8 @@ # define SR_PE (1 << 5) # define SR_FE (1 << 6) # define SR_BRK (1 << 7) +#define SCCNXP_CSR_REG (SCCNXP_SR_REG) +# define CSR_TIMER_MODE (0x0d) #define SCCNXP_CR_REG (0x02) # define CR_RX_ENABLE (1 << 0) # define CR_RX_DISABLE (1 << 1) @@ -85,9 +80,12 @@ # define IMR_RXRDY (1 << 1) # define ISR_TXRDY(x) (1 << ((x * 4) + 0)) # define ISR_RXRDY(x) (1 << ((x * 4) + 1)) +#define SCCNXP_CTPU_REG (0x06) +#define SCCNXP_CTPL_REG (0x07) #define SCCNXP_IPR_REG (0x0d) #define SCCNXP_OPCR_REG SCCNXP_IPR_REG #define SCCNXP_SOP_REG (0x0e) +#define SCCNXP_START_COUNTER_REG SCCNXP_SOP_REG #define SCCNXP_ROP_REG (0x0f) /* Route helpers */ @@ -106,6 +104,8 @@ struct sccnxp_chip { unsigned long freq_max; unsigned int flags; unsigned int fifosize; + /* Time between read/write cycles */ + unsigned int trwd; }; struct sccnxp_port { @@ -140,6 +140,7 @@ static const struct sccnxp_chip sc2681 = { .freq_max = 4000000, .flags = SCCNXP_HAVE_IO, .fifosize = 3, + .trwd = 200, }; static const struct sccnxp_chip sc2691 = { @@ -150,6 +151,7 @@ static const struct sccnxp_chip sc2691 = { .freq_max = 4000000, .flags = 0, .fifosize = 3, + .trwd = 150, }; static const struct sccnxp_chip sc2692 = { @@ -160,6 +162,7 @@ static const struct sccnxp_chip sc2692 = { .freq_max = 4000000, .flags = SCCNXP_HAVE_IO, .fifosize = 3, + .trwd = 30, }; static const struct sccnxp_chip sc2891 = { @@ -170,6 +173,7 @@ static const struct sccnxp_chip sc2891 = { .freq_max = 8000000, .flags = SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0, .fifosize = 16, + .trwd = 27, }; static const struct sccnxp_chip sc2892 = { @@ -180,6 +184,7 @@ static const struct sccnxp_chip sc2892 = { .freq_max = 8000000, .flags = SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0, .fifosize = 16, + .trwd = 17, }; static const struct sccnxp_chip sc28202 = { @@ -190,6 +195,7 @@ static const struct sccnxp_chip sc28202 = { .freq_max = 50000000, .flags = SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0, .fifosize = 256, + .trwd = 10, }; static const struct sccnxp_chip sc68681 = { @@ -200,6 +206,7 @@ static const struct sccnxp_chip sc68681 = { .freq_max = 4000000, .flags = SCCNXP_HAVE_IO, .fifosize = 3, + .trwd = 200, }; static const struct sccnxp_chip sc68692 = { @@ -210,24 +217,36 @@ static const struct sccnxp_chip sc68692 = { .freq_max = 4000000, .flags = SCCNXP_HAVE_IO, .fifosize = 3, + .trwd = 200, }; -static inline u8 sccnxp_read(struct uart_port *port, u8 reg) +static u8 sccnxp_read(struct uart_port *port, u8 reg) { - return readb(port->membase + (reg << port->regshift)); + struct sccnxp_port *s = dev_get_drvdata(port->dev); + u8 ret; + + ret = readb(port->membase + (reg << port->regshift)); + + ndelay(s->chip->trwd); + + return ret; } -static inline void sccnxp_write(struct uart_port *port, u8 reg, u8 v) +static void sccnxp_write(struct uart_port *port, u8 reg, u8 v) { + struct sccnxp_port *s = dev_get_drvdata(port->dev); + writeb(v, port->membase + (reg << port->regshift)); + + ndelay(s->chip->trwd); } -static inline u8 sccnxp_port_read(struct uart_port *port, u8 reg) +static u8 sccnxp_port_read(struct uart_port *port, u8 reg) { return sccnxp_read(port, (port->line << 3) + reg); } -static inline void sccnxp_port_write(struct uart_port *port, u8 reg, u8 v) +static void sccnxp_port_write(struct uart_port *port, u8 reg, u8 v) { sccnxp_write(port, (port->line << 3) + reg, v); } @@ -236,7 +255,7 @@ static int sccnxp_update_best_err(int a, int b, int *besterr) { int err = abs(a - b); - if ((*besterr < 0) || (*besterr > err)) { + if (*besterr > err) { *besterr = err; return 0; } @@ -284,10 +303,22 @@ static const struct { static int sccnxp_set_baud(struct uart_port *port, int baud) { struct sccnxp_port *s = dev_get_drvdata(port->dev); - int div_std, tmp_baud, bestbaud = baud, besterr = -1; + int div_std, tmp_baud, bestbaud = INT_MAX, besterr = INT_MAX; struct sccnxp_chip *chip = s->chip; u8 i, acr = 0, csr = 0, mr0 = 0; + /* Find divisor to load to the timer preset registers */ + div_std = DIV_ROUND_CLOSEST(port->uartclk, 2 * 16 * baud); + if ((div_std >= 2) && (div_std <= 0xffff)) { + bestbaud = DIV_ROUND_CLOSEST(port->uartclk, 2 * 16 * div_std); + sccnxp_update_best_err(baud, bestbaud, &besterr); + csr = CSR_TIMER_MODE; + sccnxp_port_write(port, SCCNXP_CTPU_REG, div_std >> 8); + sccnxp_port_write(port, SCCNXP_CTPL_REG, div_std); + /* Issue start timer/counter command */ + sccnxp_port_read(port, SCCNXP_START_COUNTER_REG); + } + /* Find best baud from table */ for (i = 0; baud_std[i].baud && besterr; i++) { if (baud_std[i].mr0 && !(chip->flags & SCCNXP_HAVE_MR0)) @@ -352,8 +383,7 @@ static void sccnxp_set_bit(struct uart_port *port, int sig, int state) static void sccnxp_handle_rx(struct uart_port *port) { - u8 sr; - unsigned int ch, flag; + u8 sr, ch, flag; for (;;) { sr = sccnxp_port_read(port, SCCNXP_SR_REG); @@ -409,7 +439,7 @@ static void sccnxp_handle_rx(struct uart_port *port) static void sccnxp_handle_tx(struct uart_port *port) { u8 sr; - struct circ_buf *xmit = &port->state->xmit; + struct tty_port *tport = &port->state->port; struct sccnxp_port *s = dev_get_drvdata(port->dev); if (unlikely(port->x_char)) { @@ -419,7 +449,7 @@ static void sccnxp_handle_tx(struct uart_port *port) return; } - if (uart_circ_empty(xmit) || uart_tx_stopped(port)) { + if (kfifo_is_empty(&tport->xmit_fifo) || uart_tx_stopped(port)) { /* Disable TX if FIFO is empty */ if (sccnxp_port_read(port, SCCNXP_SR_REG) & SR_TXEMT) { sccnxp_disable_irq(port, IMR_TXRDY); @@ -431,17 +461,20 @@ static void sccnxp_handle_tx(struct uart_port *port) return; } - while (!uart_circ_empty(xmit)) { + while (1) { + unsigned char ch; + sr = sccnxp_port_read(port, SCCNXP_SR_REG); if (!(sr & SR_TXRDY)) break; - sccnxp_port_write(port, SCCNXP_THR_REG, xmit->buf[xmit->tail]); - xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); - port->icount.tx++; + if (!uart_fifo_get(port, &ch)) + break; + + sccnxp_port_write(port, SCCNXP_THR_REG, ch); } - if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS) uart_write_wakeup(port); } @@ -465,9 +498,9 @@ static void sccnxp_handle_events(struct sccnxp_port *s) } while (1); } -static void sccnxp_timer(unsigned long data) +static void sccnxp_timer(struct timer_list *t) { - struct sccnxp_port *s = (struct sccnxp_port *)data; + struct sccnxp_port *s = timer_container_of(s, t, timer); unsigned long flags; spin_lock_irqsave(&s->lock, flags); @@ -605,7 +638,8 @@ static void sccnxp_break_ctl(struct uart_port *port, int break_state) } static void sccnxp_set_termios(struct uart_port *port, - struct ktermios *termios, struct ktermios *old) + struct ktermios *termios, + const struct ktermios *old) { struct sccnxp_port *s = dev_get_drvdata(port->dev); unsigned long flags; @@ -797,7 +831,7 @@ static const struct uart_ops sccnxp_ops = { }; #ifdef CONFIG_SERIAL_SCCNXP_CONSOLE -static void sccnxp_console_putchar(struct uart_port *port, int c) +static void sccnxp_console_putchar(struct uart_port *port, unsigned char c) { int tryes = 100000; @@ -849,14 +883,14 @@ MODULE_DEVICE_TABLE(platform, sccnxp_id_table); static int sccnxp_probe(struct platform_device *pdev) { - struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0); struct sccnxp_pdata *pdata = dev_get_platdata(&pdev->dev); + struct resource *res; int i, ret, uartclk; struct sccnxp_port *s; void __iomem *membase; struct clk *clk; - membase = devm_ioremap_resource(&pdev->dev, res); + membase = devm_platform_get_and_ioremap_resource(pdev, 0, &res); if (IS_ERR(membase)) return PTR_ERR(membase); @@ -882,14 +916,13 @@ static int sccnxp_probe(struct platform_device *pdev) } else if (PTR_ERR(s->regulator) == -EPROBE_DEFER) return -EPROBE_DEFER; - clk = devm_clk_get(&pdev->dev, NULL); + clk = devm_clk_get_enabled(&pdev->dev, NULL); if (IS_ERR(clk)) { ret = PTR_ERR(clk); if (ret == -EPROBE_DEFER) goto err_out; uartclk = 0; } else { - clk_prepare_enable(clk); uartclk = clk_get_rate(clk); } @@ -917,7 +950,6 @@ static int sccnxp_probe(struct platform_device *pdev) if (!s->poll) { s->irq = platform_get_irq(pdev, 0); if (s->irq < 0) { - dev_err(&pdev->dev, "Missing irq resource data\n"); ret = -ENXIO; goto err_out; } @@ -957,6 +989,7 @@ static int sccnxp_probe(struct platform_device *pdev) s->port[i].regshift = s->pdata.reg_shift; s->port[i].uartclk = uartclk; s->port[i].ops = &sccnxp_ops; + s->port[i].has_sysrq = IS_ENABLED(CONFIG_SERIAL_SCCNXP_CONSOLE); uart_add_one_port(&s->uart, &s->port[i]); /* Set direction to input */ if (s->chip->flags & SCCNXP_HAVE_IO) @@ -978,8 +1011,7 @@ static int sccnxp_probe(struct platform_device *pdev) dev_err(&pdev->dev, "Unable to reguest IRQ %i\n", s->irq); } else { - init_timer(&s->timer); - setup_timer(&s->timer, sccnxp_timer, (unsigned long)s); + timer_setup(&s->timer, sccnxp_timer, 0); mod_timer(&s->timer, jiffies + usecs_to_jiffies(s->pdata.poll_time_us)); return 0; @@ -988,12 +1020,12 @@ static int sccnxp_probe(struct platform_device *pdev) uart_unregister_driver(&s->uart); err_out: if (!IS_ERR(s->regulator)) - return regulator_disable(s->regulator); + regulator_disable(s->regulator); return ret; } -static int sccnxp_remove(struct platform_device *pdev) +static void sccnxp_remove(struct platform_device *pdev) { int i; struct sccnxp_port *s = platform_get_drvdata(pdev); @@ -1001,17 +1033,18 @@ static int sccnxp_remove(struct platform_device *pdev) if (!s->poll) devm_free_irq(&pdev->dev, s->irq, s); else - del_timer_sync(&s->timer); + timer_delete_sync(&s->timer); for (i = 0; i < s->uart.nr; i++) uart_remove_one_port(&s->uart, &s->port[i]); uart_unregister_driver(&s->uart); - if (!IS_ERR(s->regulator)) - return regulator_disable(s->regulator); - - return 0; + if (!IS_ERR(s->regulator)) { + int ret = regulator_disable(s->regulator); + if (ret) + dev_err(&pdev->dev, "Failed to disable regulator\n"); + } } static struct platform_driver sccnxp_uart_driver = { |