diff options
Diffstat (limited to 'drivers/tty/serial/bcm63xx_uart.c')
| -rw-r--r-- | drivers/tty/serial/bcm63xx_uart.c | 263 |
1 files changed, 142 insertions, 121 deletions
diff --git a/drivers/tty/serial/bcm63xx_uart.c b/drivers/tty/serial/bcm63xx_uart.c index 6fa2ae77fffd..51df9d2d8bfc 100644 --- a/drivers/tty/serial/bcm63xx_uart.c +++ b/drivers/tty/serial/bcm63xx_uart.c @@ -1,8 +1,5 @@ +// SPDX-License-Identifier: GPL-2.0 /* - * This file is subject to the terms and conditions of the GNU General Public - * License. See the file "COPYING" in the main directory of this archive - * for more details. - * * Derived from many drivers using generic_serial interface. * * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr> @@ -13,10 +10,6 @@ * my board. */ -#if defined(CONFIG_SERIAL_BCM63XX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) -#define SUPPORT_SYSRQ -#endif - #include <linux/kernel.h> #include <linux/platform_device.h> #include <linux/init.h> @@ -29,10 +22,9 @@ #include <linux/sysrq.h> #include <linux/serial.h> #include <linux/serial_core.h> - -#include <bcm63xx_irq.h> -#include <bcm63xx_regs.h> -#include <bcm63xx_io.h> +#include <linux/serial_bcm63xx.h> +#include <linux/io.h> +#include <linux/of.h> #define BCM63XX_NR_UARTS 2 @@ -81,13 +73,13 @@ static struct uart_port ports[BCM63XX_NR_UARTS]; static inline unsigned int bcm_uart_readl(struct uart_port *port, unsigned int offset) { - return bcm_readl(port->membase + offset); + return __raw_readl(port->membase + offset); } static inline void bcm_uart_writel(struct uart_port *port, unsigned int value, unsigned int offset) { - bcm_writel(value, port->membase + offset); + __raw_writel(value, port->membase + offset); } /* @@ -209,7 +201,7 @@ static void bcm_uart_break_ctl(struct uart_port *port, int ctl) unsigned long flags; unsigned int val; - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); val = bcm_uart_readl(port, UART_CTL_REG); if (ctl) @@ -218,7 +210,7 @@ static void bcm_uart_break_ctl(struct uart_port *port, int ctl) val &= ~UART_CTL_XMITBRK_MASK; bcm_uart_writel(port, val, UART_CTL_REG); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } /* @@ -293,10 +285,9 @@ static void bcm_uart_do_rx(struct uart_port *port) flag = TTY_PARITY; } - if (uart_handle_sysrq_char(port, c)) + if (uart_prepare_sysrq_char(port, c)) continue; - if ((cstat & port->ignore_status_mask) == 0) tty_insert_flip_char(tty_port, c, flag); @@ -311,53 +302,27 @@ static void bcm_uart_do_rx(struct uart_port *port) */ static void bcm_uart_do_tx(struct uart_port *port) { - struct circ_buf *xmit; - unsigned int val, max_count; - - if (port->x_char) { - bcm_uart_writel(port, port->x_char, UART_FIFO_REG); - port->icount.tx++; - port->x_char = 0; - return; - } - - if (uart_tx_stopped(port)) { - bcm_uart_stop_tx(port); - return; - } - - xmit = &port->state->xmit; - if (uart_circ_empty(xmit)) - goto txq_empty; + unsigned int val; + bool pending; + u8 ch; val = bcm_uart_readl(port, UART_MCTL_REG); val = (val & UART_MCTL_TXFIFOFILL_MASK) >> UART_MCTL_TXFIFOFILL_SHIFT; - max_count = port->fifosize - val; - - while (max_count--) { - unsigned int c; - - c = xmit->buf[xmit->tail]; - bcm_uart_writel(port, c, UART_FIFO_REG); - xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); - port->icount.tx++; - if (uart_circ_empty(xmit)) - break; - } - - if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) - uart_write_wakeup(port); - - if (uart_circ_empty(xmit)) - goto txq_empty; - return; + pending = uart_port_tx_limited_flags(port, ch, UART_TX_NOSTOP, + port->fifosize - val, + true, + bcm_uart_writel(port, ch, UART_FIFO_REG), + ({})); + if (pending) + return; -txq_empty: /* nothing to send, disable transmit interrupt */ val = bcm_uart_readl(port, UART_IR_REG); val &= ~UART_TX_INT_MASK; bcm_uart_writel(port, val, UART_IR_REG); - return; + + if (uart_tx_stopped(port)) + bcm_uart_stop_tx(port); } /* @@ -369,7 +334,7 @@ static irqreturn_t bcm_uart_interrupt(int irq, void *dev_id) unsigned int irqstat; port = dev_id; - spin_lock(&port->lock); + uart_port_lock(port); irqstat = bcm_uart_readl(port, UART_IR_REG); if (irqstat & UART_RX_INT_STAT) @@ -390,7 +355,7 @@ static irqreturn_t bcm_uart_interrupt(int irq, void *dev_id) estat & UART_EXTINP_DCD_MASK); } - spin_unlock(&port->lock); + uart_unlock_and_check_sysrq(port); return IRQ_HANDLED; } @@ -473,7 +438,7 @@ static int bcm_uart_startup(struct uart_port *port) /* register irq and enable rx interrupts */ ret = request_irq(port->irq, bcm_uart_interrupt, 0, - bcm_uart_type(port), port); + dev_name(port->dev), port); if (ret) return ret; bcm_uart_writel(port, UART_RX_INT_MASK, UART_IR_REG); @@ -488,9 +453,9 @@ static void bcm_uart_shutdown(struct uart_port *port) { unsigned long flags; - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); bcm_uart_writel(port, 0, UART_IR_REG); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); bcm_uart_disable(port); bcm_uart_flush(port); @@ -500,14 +465,18 @@ static void bcm_uart_shutdown(struct uart_port *port) /* * serial core request to change current uart setting */ -static void bcm_uart_set_termios(struct uart_port *port, - struct ktermios *new, - struct ktermios *old) +static void bcm_uart_set_termios(struct uart_port *port, struct ktermios *new, + const struct ktermios *old) { unsigned int ctl, baud, quot, ier; unsigned long flags; + int tries; - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); + + /* Drain the hot tub fully before we power it off for the winter. */ + for (tries = 3; !bcm_uart_tx_empty(port) && tries; tries--) + mdelay(10); /* disable uart while changing speed */ bcm_uart_disable(port); @@ -566,7 +535,7 @@ static void bcm_uart_set_termios(struct uart_port *port, port->read_status_mask |= UART_FIFO_FRAMEERR_MASK; port->read_status_mask |= UART_FIFO_PARERR_MASK; } - if (new->c_iflag & (BRKINT)) + if (new->c_iflag & (IGNBRK | BRKINT)) port->read_status_mask |= UART_FIFO_BRKDET_MASK; port->ignore_status_mask = 0; @@ -579,7 +548,7 @@ static void bcm_uart_set_termios(struct uart_port *port, uart_update_timeout(port, new->c_cflag, baud); bcm_uart_enable(port); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } /* @@ -587,20 +556,7 @@ static void bcm_uart_set_termios(struct uart_port *port, */ static int bcm_uart_request_port(struct uart_port *port) { - unsigned int size; - - size = RSET_UART_SIZE; - if (!request_mem_region(port->mapbase, size, "bcm63xx")) { - dev_err(port->dev, "Memory region busy\n"); - return -EBUSY; - } - - port->membase = ioremap(port->mapbase, size); - if (!port->membase) { - dev_err(port->dev, "Unable to map registers\n"); - release_mem_region(port->mapbase, size); - return -EBUSY; - } + /* UARTs always present */ return 0; } @@ -609,8 +565,7 @@ static int bcm_uart_request_port(struct uart_port *port) */ static void bcm_uart_release_port(struct uart_port *port) { - release_mem_region(port->mapbase, RSET_UART_SIZE); - iounmap(port->membase); + /* Nothing to release ... */ } /* @@ -643,8 +598,42 @@ static int bcm_uart_verify_port(struct uart_port *port, return 0; } +#ifdef CONFIG_CONSOLE_POLL +/* + * return true when outstanding tx equals fifo size + */ +static bool bcm_uart_tx_full(struct uart_port *port) +{ + unsigned int val; + + val = bcm_uart_readl(port, UART_MCTL_REG); + val = (val & UART_MCTL_TXFIFOFILL_MASK) >> UART_MCTL_TXFIFOFILL_SHIFT; + return !(port->fifosize - val); +} + +static int bcm_uart_poll_get_char(struct uart_port *port) +{ + unsigned int iestat; + + iestat = bcm_uart_readl(port, UART_IR_REG); + if (!(iestat & UART_IR_STAT(UART_IR_RXNOTEMPTY))) + return NO_POLL_CHAR; + + return bcm_uart_readl(port, UART_FIFO_REG); +} + +static void bcm_uart_poll_put_char(struct uart_port *port, unsigned char c) +{ + while (bcm_uart_tx_full(port)) { + cpu_relax(); + } + + bcm_uart_writel(port, c, UART_FIFO_REG); +} +#endif + /* serial core callbacks */ -static struct uart_ops bcm_uart_ops = { +static const struct uart_ops bcm_uart_ops = { .tx_empty = bcm_uart_tx_empty, .get_mctrl = bcm_uart_get_mctrl, .set_mctrl = bcm_uart_set_mctrl, @@ -661,12 +650,16 @@ static struct uart_ops bcm_uart_ops = { .request_port = bcm_uart_request_port, .config_port = bcm_uart_config_port, .verify_port = bcm_uart_verify_port, +#ifdef CONFIG_CONSOLE_POLL + .poll_get_char = bcm_uart_poll_get_char, + .poll_put_char = bcm_uart_poll_put_char, +#endif }; #ifdef CONFIG_SERIAL_BCM63XX_CONSOLE -static inline void wait_for_xmitr(struct uart_port *port) +static void wait_for_xmitr(struct uart_port *port) { unsigned int tmout; @@ -698,7 +691,7 @@ static inline void wait_for_xmitr(struct uart_port *port) /* * output given char */ -static void bcm_console_putchar(struct uart_port *port, int ch) +static void bcm_console_putchar(struct uart_port *port, unsigned char ch) { wait_for_xmitr(port); bcm_uart_writel(port, ch, UART_FIFO_REG); @@ -712,20 +705,14 @@ static void bcm_console_write(struct console *co, const char *s, { struct uart_port *port; unsigned long flags; - int locked; + int locked = 1; port = &ports[co->index]; - local_irq_save(flags); - if (port->sysrq) { - /* bcm_uart_interrupt() already took the lock */ - locked = 0; - } else if (oops_in_progress) { - locked = spin_trylock(&port->lock); - } else { - spin_lock(&port->lock); - locked = 1; - } + if (oops_in_progress) + locked = uart_port_trylock_irqsave(port, &flags); + else + uart_port_lock_irqsave(port, &flags); /* call helper to deal with \r\n */ uart_console_write(port, s, count, bcm_console_putchar); @@ -734,8 +721,7 @@ static void bcm_console_write(struct console *co, const char *s, wait_for_xmitr(port); if (locked) - spin_unlock(&port->lock); - local_irq_restore(flags); + uart_port_unlock_irqrestore(port, flags); } /* @@ -781,6 +767,26 @@ static int __init bcm63xx_console_init(void) console_initcall(bcm63xx_console_init); +static void bcm_early_write(struct console *con, const char *s, unsigned n) +{ + struct earlycon_device *dev = con->data; + + uart_console_write(&dev->port, s, n, bcm_console_putchar); + wait_for_xmitr(&dev->port); +} + +static int __init bcm_early_console_setup(struct earlycon_device *device, + const char *opt) +{ + if (!device->port.membase) + return -ENODEV; + + device->con->write = bcm_early_write; + return 0; +} + +OF_EARLYCON_DECLARE(bcm63xx_uart, "brcm,bcm6345-uart", bcm_early_console_setup); + #define BCM63XX_CONSOLE (&bcm63xx_console) #else #define BCM63XX_CONSOLE NULL @@ -801,72 +807,87 @@ static struct uart_driver bcm_uart_driver = { */ static int bcm_uart_probe(struct platform_device *pdev) { - struct resource *res_mem, *res_irq; + struct resource *res_mem; struct uart_port *port; struct clk *clk; int ret; + if (pdev->dev.of_node) { + pdev->id = of_alias_get_id(pdev->dev.of_node, "serial"); + + if (pdev->id < 0) + pdev->id = of_alias_get_id(pdev->dev.of_node, "uart"); + } + if (pdev->id < 0 || pdev->id >= BCM63XX_NR_UARTS) return -EINVAL; - if (ports[pdev->id].membase) + port = &ports[pdev->id]; + if (port->membase) return -EBUSY; + memset(port, 0, sizeof(*port)); - res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (!res_mem) - return -ENODEV; + port->membase = devm_platform_get_and_ioremap_resource(pdev, 0, &res_mem); + if (IS_ERR(port->membase)) + return PTR_ERR(port->membase); + port->mapbase = res_mem->start; - res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); - if (!res_irq) - return -ENODEV; + ret = platform_get_irq(pdev, 0); + if (ret < 0) + return ret; + port->irq = ret; + + clk = clk_get(&pdev->dev, "refclk"); + if (IS_ERR(clk) && pdev->dev.of_node) + clk = of_clk_get(pdev->dev.of_node, 0); - clk = clk_get(&pdev->dev, "periph"); if (IS_ERR(clk)) return -ENODEV; - port = &ports[pdev->id]; - memset(port, 0, sizeof(*port)); port->iotype = UPIO_MEM; - port->mapbase = res_mem->start; - port->irq = res_irq->start; port->ops = &bcm_uart_ops; port->flags = UPF_BOOT_AUTOCONF; port->dev = &pdev->dev; port->fifosize = 16; port->uartclk = clk_get_rate(clk) / 2; port->line = pdev->id; + port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_BCM63XX_CONSOLE); clk_put(clk); ret = uart_add_one_port(&bcm_uart_driver, port); if (ret) { - ports[pdev->id].membase = 0; + ports[pdev->id].membase = NULL; return ret; } platform_set_drvdata(pdev, port); return 0; } -static int bcm_uart_remove(struct platform_device *pdev) +static void bcm_uart_remove(struct platform_device *pdev) { struct uart_port *port; port = platform_get_drvdata(pdev); uart_remove_one_port(&bcm_uart_driver, port); - platform_set_drvdata(pdev, NULL); /* mark port as free */ - ports[pdev->id].membase = 0; - return 0; + ports[pdev->id].membase = NULL; } +static const struct of_device_id bcm63xx_of_match[] = { + { .compatible = "brcm,bcm6345-uart" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, bcm63xx_of_match); + /* * platform driver stuff */ static struct platform_driver bcm_uart_platform_driver = { .probe = bcm_uart_probe, - .remove = bcm_uart_remove, + .remove = bcm_uart_remove, .driver = { - .owner = THIS_MODULE, .name = "bcm63xx_uart", + .of_match_table = bcm63xx_of_match, }, }; @@ -895,5 +916,5 @@ module_init(bcm_uart_init); module_exit(bcm_uart_exit); MODULE_AUTHOR("Maxime Bizon <mbizon@freebox.fr>"); -MODULE_DESCRIPTION("Broadcom 63<xx integrated uart driver"); +MODULE_DESCRIPTION("Broadcom 63xx integrated uart driver"); MODULE_LICENSE("GPL"); |
