diff options
author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2012-02-10 16:52:55 +0100 |
---|---|---|
committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2012-02-10 17:14:49 +0100 |
commit | 9edd576d89a5b6d3e136d7dcab654d887c0d25b7 (patch) | |
tree | d19670de2256f8187321de3a41fa4a10d3c8e402 /drivers/tty/serial/ar933x_uart.c | |
parent | e21af88d39796c907c38648c824be3d646ffbe35 (diff) | |
parent | 28a4d5675857f6386930a324317281cb8ed1e5d0 (diff) |
Merge remote-tracking branch 'airlied/drm-fixes' into drm-intel-next-queued
Back-merge from drm-fixes into drm-intel-next to sort out two things:
- interlaced support: -fixes contains a bugfix to correctly clear
interlaced configuration bits in case the bios sets up an interlaced
mode and we want to set up the progressive mode (current kernels
don't support interlaced). The actual feature work to support
interlaced depends upon (and conflicts with) this bugfix.
- forcewake voodoo to workaround missed IRQ issues: -fixes only enabled
this for ivybridge, but some recent bug reports indicate that we
need this on Sandybridge, too. But in a slightly different flavour
and with other fixes and reworks on top. Additionally there are some
forcewake cleanup patches heading to -next that would conflict with
currrent -fixes.
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'drivers/tty/serial/ar933x_uart.c')
-rw-r--r-- | drivers/tty/serial/ar933x_uart.c | 688 |
1 files changed, 688 insertions, 0 deletions
diff --git a/drivers/tty/serial/ar933x_uart.c b/drivers/tty/serial/ar933x_uart.c new file mode 100644 index 00000000000..e4f60e2b87f --- /dev/null +++ b/drivers/tty/serial/ar933x_uart.c @@ -0,0 +1,688 @@ +/* + * Atheros AR933X SoC built-in UART driver + * + * Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org> + * + * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + */ + +#include <linux/module.h> +#include <linux/ioport.h> +#include <linux/init.h> +#include <linux/console.h> +#include <linux/sysrq.h> +#include <linux/delay.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/slab.h> +#include <linux/io.h> +#include <linux/irq.h> + +#include <asm/mach-ath79/ar933x_uart.h> +#include <asm/mach-ath79/ar933x_uart_platform.h> + +#define DRIVER_NAME "ar933x-uart" + +#define AR933X_DUMMY_STATUS_RD 0x01 + +static struct uart_driver ar933x_uart_driver; + +struct ar933x_uart_port { + struct uart_port port; + unsigned int ier; /* shadow Interrupt Enable Register */ +}; + +static inline unsigned int ar933x_uart_read(struct ar933x_uart_port *up, + int offset) +{ + return readl(up->port.membase + offset); +} + +static inline void ar933x_uart_write(struct ar933x_uart_port *up, + int offset, unsigned int value) +{ + writel(value, up->port.membase + offset); +} + +static inline void ar933x_uart_rmw(struct ar933x_uart_port *up, + unsigned int offset, + unsigned int mask, + unsigned int val) +{ + unsigned int t; + + t = ar933x_uart_read(up, offset); + t &= ~mask; + t |= val; + ar933x_uart_write(up, offset, t); +} + +static inline void ar933x_uart_rmw_set(struct ar933x_uart_port *up, + unsigned int offset, + unsigned int val) +{ + ar933x_uart_rmw(up, offset, 0, val); +} + +static inline void ar933x_uart_rmw_clear(struct ar933x_uart_port *up, + unsigned int offset, + unsigned int val) +{ + ar933x_uart_rmw(up, offset, val, 0); +} + +static inline void ar933x_uart_start_tx_interrupt(struct ar933x_uart_port *up) +{ + up->ier |= AR933X_UART_INT_TX_EMPTY; + ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier); +} + +static inline void ar933x_uart_stop_tx_interrupt(struct ar933x_uart_port *up) +{ + up->ier &= ~AR933X_UART_INT_TX_EMPTY; + ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier); +} + +static inline void ar933x_uart_putc(struct ar933x_uart_port *up, int ch) +{ + unsigned int rdata; + + rdata = ch & AR933X_UART_DATA_TX_RX_MASK; + rdata |= AR933X_UART_DATA_TX_CSR; + ar933x_uart_write(up, AR933X_UART_DATA_REG, rdata); +} + +static unsigned int ar933x_uart_tx_empty(struct uart_port *port) +{ + struct ar933x_uart_port *up = (struct ar933x_uart_port *) port; + unsigned long flags; + unsigned int rdata; + + spin_lock_irqsave(&up->port.lock, flags); + rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG); + spin_unlock_irqrestore(&up->port.lock, flags); + + return (rdata & AR933X_UART_DATA_TX_CSR) ? 0 : TIOCSER_TEMT; +} + +static unsigned int ar933x_uart_get_mctrl(struct uart_port *port) +{ + return TIOCM_CAR; +} + +static void ar933x_uart_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ +} + +static void ar933x_uart_start_tx(struct uart_port *port) +{ + struct ar933x_uart_port *up = (struct ar933x_uart_port *) port; + + ar933x_uart_start_tx_interrupt(up); +} + +static void ar933x_uart_stop_tx(struct uart_port *port) +{ + struct ar933x_uart_port *up = (struct ar933x_uart_port *) port; + + ar933x_uart_stop_tx_interrupt(up); +} + +static void ar933x_uart_stop_rx(struct uart_port *port) +{ + struct ar933x_uart_port *up = (struct ar933x_uart_port *) port; + + up->ier &= ~AR933X_UART_INT_RX_VALID; + ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier); +} + +static void ar933x_uart_break_ctl(struct uart_port *port, int break_state) +{ + struct ar933x_uart_port *up = (struct ar933x_uart_port *) port; + unsigned long flags; + + spin_lock_irqsave(&up->port.lock, flags); + if (break_state == -1) + ar933x_uart_rmw_set(up, AR933X_UART_CS_REG, + AR933X_UART_CS_TX_BREAK); + else + ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG, + AR933X_UART_CS_TX_BREAK); + spin_unlock_irqrestore(&up->port.lock, flags); +} + +static void ar933x_uart_enable_ms(struct uart_port *port) +{ +} + +static void ar933x_uart_set_termios(struct uart_port *port, + struct ktermios *new, + struct ktermios *old) +{ + struct ar933x_uart_port *up = (struct ar933x_uart_port *) port; + unsigned int cs; + unsigned long flags; + unsigned int baud, scale; + + /* Only CS8 is supported */ + new->c_cflag &= ~CSIZE; + new->c_cflag |= CS8; + + /* Only one stop bit is supported */ + new->c_cflag &= ~CSTOPB; + + cs = 0; + if (new->c_cflag & PARENB) { + if (!(new->c_cflag & PARODD)) + cs |= AR933X_UART_CS_PARITY_EVEN; + else + cs |= AR933X_UART_CS_PARITY_ODD; + } else { + cs |= AR933X_UART_CS_PARITY_NONE; + } + + /* Mark/space parity is not supported */ + new->c_cflag &= ~CMSPAR; + + baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16); + scale = (port->uartclk / (16 * baud)) - 1; + + /* + * Ok, we're now changing the port state. Do it with + * interrupts disabled. + */ + spin_lock_irqsave(&up->port.lock, flags); + + /* Update the per-port timeout. */ + uart_update_timeout(port, new->c_cflag, baud); + + up->port.ignore_status_mask = 0; + + /* ignore all characters if CREAD is not set */ + if ((new->c_cflag & CREAD) == 0) + up->port.ignore_status_mask |= AR933X_DUMMY_STATUS_RD; + + ar933x_uart_write(up, AR933X_UART_CLOCK_REG, + scale << AR933X_UART_CLOCK_SCALE_S | 8192); + + /* setup configuration register */ + ar933x_uart_rmw(up, AR933X_UART_CS_REG, AR933X_UART_CS_PARITY_M, cs); + + /* enable host interrupt */ + ar933x_uart_rmw_set(up, AR933X_UART_CS_REG, + AR933X_UART_CS_HOST_INT_EN); + + spin_unlock_irqrestore(&up->port.lock, flags); + + if (tty_termios_baud_rate(new)) + tty_termios_encode_baud_rate(new, baud, baud); +} + +static void ar933x_uart_rx_chars(struct ar933x_uart_port *up) +{ + struct tty_struct *tty; + int max_count = 256; + + tty = tty_port_tty_get(&up->port.state->port); + do { + unsigned int rdata; + unsigned char ch; + + rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG); + if ((rdata & AR933X_UART_DATA_RX_CSR) == 0) + break; + + /* remove the character from the FIFO */ + ar933x_uart_write(up, AR933X_UART_DATA_REG, + AR933X_UART_DATA_RX_CSR); + + if (!tty) { + /* discard the data if no tty available */ + continue; + } + + up->port.icount.rx++; + ch = rdata & AR933X_UART_DATA_TX_RX_MASK; + + if (uart_handle_sysrq_char(&up->port, ch)) + continue; + + if ((up->port.ignore_status_mask & AR933X_DUMMY_STATUS_RD) == 0) + tty_insert_flip_char(tty, ch, TTY_NORMAL); + } while (max_count-- > 0); + + if (tty) { + tty_flip_buffer_push(tty); + tty_kref_put(tty); + } +} + +static void ar933x_uart_tx_chars(struct ar933x_uart_port *up) +{ + struct circ_buf *xmit = &up->port.state->xmit; + int count; + + if (uart_tx_stopped(&up->port)) + return; + + count = up->port.fifosize; + do { + unsigned int rdata; + + rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG); + if ((rdata & AR933X_UART_DATA_TX_CSR) == 0) + break; + + if (up->port.x_char) { + ar933x_uart_putc(up, up->port.x_char); + up->port.icount.tx++; + up->port.x_char = 0; + continue; + } + + if (uart_circ_empty(xmit)) + break; + + ar933x_uart_putc(up, xmit->buf[xmit->tail]); + + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + up->port.icount.tx++; + } while (--count > 0); + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(&up->port); + + if (!uart_circ_empty(xmit)) + ar933x_uart_start_tx_interrupt(up); +} + +static irqreturn_t ar933x_uart_interrupt(int irq, void *dev_id) +{ + struct ar933x_uart_port *up = dev_id; + unsigned int status; + + status = ar933x_uart_read(up, AR933X_UART_CS_REG); + if ((status & AR933X_UART_CS_HOST_INT) == 0) + return IRQ_NONE; + + spin_lock(&up->port.lock); + + status = ar933x_uart_read(up, AR933X_UART_INT_REG); + status &= ar933x_uart_read(up, AR933X_UART_INT_EN_REG); + + if (status & AR933X_UART_INT_RX_VALID) { + ar933x_uart_write(up, AR933X_UART_INT_REG, + AR933X_UART_INT_RX_VALID); + ar933x_uart_rx_chars(up); + } + + if (status & AR933X_UART_INT_TX_EMPTY) { + ar933x_uart_write(up, AR933X_UART_INT_REG, + AR933X_UART_INT_TX_EMPTY); + ar933x_uart_stop_tx_interrupt(up); + ar933x_uart_tx_chars(up); + } + + spin_unlock(&up->port.lock); + + return IRQ_HANDLED; +} + +static int ar933x_uart_startup(struct uart_port *port) +{ + struct ar933x_uart_port *up = (struct ar933x_uart_port *) port; + unsigned long flags; + int ret; + + ret = request_irq(up->port.irq, ar933x_uart_interrupt, + up->port.irqflags, dev_name(up->port.dev), up); + if (ret) + return ret; + + spin_lock_irqsave(&up->port.lock, flags); + + /* Enable HOST interrupts */ + ar933x_uart_rmw_set(up, AR933X_UART_CS_REG, + AR933X_UART_CS_HOST_INT_EN); + + /* Enable RX interrupts */ + up->ier = AR933X_UART_INT_RX_VALID; + ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier); + + spin_unlock_irqrestore(&up->port.lock, flags); + + return 0; +} + +static void ar933x_uart_shutdown(struct uart_port *port) +{ + struct ar933x_uart_port *up = (struct ar933x_uart_port *) port; + + /* Disable all interrupts */ + up->ier = 0; + ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier); + + /* Disable break condition */ + ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG, + AR933X_UART_CS_TX_BREAK); + + free_irq(up->port.irq, up); +} + +static const char *ar933x_uart_type(struct uart_port *port) +{ + return (port->type == PORT_AR933X) ? "AR933X UART" : NULL; +} + +static void ar933x_uart_release_port(struct uart_port *port) +{ + /* Nothing to release ... */ +} + +static int ar933x_uart_request_port(struct uart_port *port) +{ + /* UARTs always present */ + return 0; +} + +static void ar933x_uart_config_port(struct uart_port *port, int flags) +{ + if (flags & UART_CONFIG_TYPE) + port->type = PORT_AR933X; +} + +static int ar933x_uart_verify_port(struct uart_port *port, + struct serial_struct *ser) +{ + if (ser->type != PORT_UNKNOWN && + ser->type != PORT_AR933X) + return -EINVAL; + + if (ser->irq < 0 || ser->irq >= NR_IRQS) + return -EINVAL; + + if (ser->baud_base < 28800) + return -EINVAL; + + return 0; +} + +static struct uart_ops ar933x_uart_ops = { + .tx_empty = ar933x_uart_tx_empty, + .set_mctrl = ar933x_uart_set_mctrl, + .get_mctrl = ar933x_uart_get_mctrl, + .stop_tx = ar933x_uart_stop_tx, + .start_tx = ar933x_uart_start_tx, + .stop_rx = ar933x_uart_stop_rx, + .enable_ms = ar933x_uart_enable_ms, + .break_ctl = ar933x_uart_break_ctl, + .startup = ar933x_uart_startup, + .shutdown = ar933x_uart_shutdown, + .set_termios = ar933x_uart_set_termios, + .type = ar933x_uart_type, + .release_port = ar933x_uart_release_port, + .request_port = ar933x_uart_request_port, + .config_port = ar933x_uart_config_port, + .verify_port = ar933x_uart_verify_port, +}; + +#ifdef CONFIG_SERIAL_AR933X_CONSOLE + +static struct ar933x_uart_port * +ar933x_console_ports[CONFIG_SERIAL_AR933X_NR_UARTS]; + +static void ar933x_uart_wait_xmitr(struct ar933x_uart_port *up) +{ + unsigned int status; + unsigned int timeout = 60000; + + /* Wait up to 60ms for the character(s) to be sent. */ + do { + status = ar933x_uart_read(up, AR933X_UART_DATA_REG); + if (--timeout == 0) + break; + udelay(1); + } while ((status & AR933X_UART_DATA_TX_CSR) == 0); +} + +static void ar933x_uart_console_putchar(struct uart_port *port, int ch) +{ + struct ar933x_uart_port *up = (struct ar933x_uart_port *) port; + + ar933x_uart_wait_xmitr(up); + ar933x_uart_putc(up, ch); +} + +static void ar933x_uart_console_write(struct console *co, const char *s, + unsigned int count) +{ + struct ar933x_uart_port *up = ar933x_console_ports[co->index]; + unsigned long flags; + unsigned int int_en; + int locked = 1; + + local_irq_save(flags); + + if (up->port.sysrq) + locked = 0; + else if (oops_in_progress) + locked = spin_trylock(&up->port.lock); + else + spin_lock(&up->port.lock); + + /* + * First save the IER then disable the interrupts + */ + int_en = ar933x_uart_read(up, AR933X_UART_INT_EN_REG); + ar933x_uart_write(up, AR933X_UART_INT_EN_REG, 0); + + uart_console_write(&up->port, s, count, ar933x_uart_console_putchar); + + /* + * Finally, wait for transmitter to become empty + * and restore the IER + */ + ar933x_uart_wait_xmitr(up); + ar933x_uart_write(up, AR933X_UART_INT_EN_REG, int_en); + + ar933x_uart_write(up, AR933X_UART_INT_REG, AR933X_UART_INT_ALLINTS); + + if (locked) + spin_unlock(&up->port.lock); + + local_irq_restore(flags); +} + +static int ar933x_uart_console_setup(struct console *co, char *options) +{ + struct ar933x_uart_port *up; + int baud = 115200; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + + if (co->index < 0 || co->index >= CONFIG_SERIAL_AR933X_NR_UARTS) + return -EINVAL; + + up = ar933x_console_ports[co->index]; + if (!up) + return -ENODEV; + + if (options) + uart_parse_options(options, &baud, &parity, &bits, &flow); + + return uart_set_options(&up->port, co, baud, parity, bits, flow); +} + +static struct console ar933x_uart_console = { + .name = "ttyATH", + .write = ar933x_uart_console_write, + .device = uart_console_device, + .setup = ar933x_uart_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &ar933x_uart_driver, +}; + +static void ar933x_uart_add_console_port(struct ar933x_uart_port *up) +{ + ar933x_console_ports[up->port.line] = up; +} + +#define AR933X_SERIAL_CONSOLE (&ar933x_uart_console) + +#else + +static inline void ar933x_uart_add_console_port(struct ar933x_uart_port *up) {} + +#define AR933X_SERIAL_CONSOLE NULL + +#endif /* CONFIG_SERIAL_AR933X_CONSOLE */ + +static struct uart_driver ar933x_uart_driver = { + .owner = THIS_MODULE, + .driver_name = DRIVER_NAME, + .dev_name = "ttyATH", + .nr = CONFIG_SERIAL_AR933X_NR_UARTS, + .cons = AR933X_SERIAL_CONSOLE, +}; + +static int __devinit ar933x_uart_probe(struct platform_device *pdev) +{ + struct ar933x_uart_platform_data *pdata; + struct ar933x_uart_port *up; + struct uart_port *port; + struct resource *mem_res; + struct resource *irq_res; + int id; + int ret; + + pdata = pdev->dev.platform_data; + if (!pdata) + return -EINVAL; + + id = pdev->id; + if (id == -1) + id = 0; + + if (id > CONFIG_SERIAL_AR933X_NR_UARTS) + return -EINVAL; + + mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!mem_res) { + dev_err(&pdev->dev, "no MEM resource\n"); + return -EINVAL; + } + + irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); + if (!irq_res) { + dev_err(&pdev->dev, "no IRQ resource\n"); + return -EINVAL; + } + + up = kzalloc(sizeof(struct ar933x_uart_port), GFP_KERNEL); + if (!up) + return -ENOMEM; + + port = &up->port; + port->mapbase = mem_res->start; + + port->membase = ioremap(mem_res->start, AR933X_UART_REGS_SIZE); + if (!port->membase) { + ret = -ENOMEM; + goto err_free_up; + } + + port->line = id; + port->irq = irq_res->start; + port->dev = &pdev->dev; + port->type = PORT_AR933X; + port->iotype = UPIO_MEM32; + port->uartclk = pdata->uartclk; + + port->regshift = 2; + port->fifosize = AR933X_UART_FIFO_SIZE; + port->ops = &ar933x_uart_ops; + + ar933x_uart_add_console_port(up); + + ret = uart_add_one_port(&ar933x_uart_driver, &up->port); + if (ret) + goto err_unmap; + + platform_set_drvdata(pdev, up); + return 0; + +err_unmap: + iounmap(up->port.membase); +err_free_up: + kfree(up); + return ret; +} + +static int __devexit ar933x_uart_remove(struct platform_device *pdev) +{ + struct ar933x_uart_port *up; + + up = platform_get_drvdata(pdev); + platform_set_drvdata(pdev, NULL); + + if (up) { + uart_remove_one_port(&ar933x_uart_driver, &up->port); + iounmap(up->port.membase); + kfree(up); + } + + return 0; +} + +static struct platform_driver ar933x_uart_platform_driver = { + .probe = ar933x_uart_probe, + .remove = __devexit_p(ar933x_uart_remove), + .driver = { + .name = DRIVER_NAME, + .owner = THIS_MODULE, + }, +}; + +static int __init ar933x_uart_init(void) +{ + int ret; + + ar933x_uart_driver.nr = CONFIG_SERIAL_AR933X_NR_UARTS; + ret = uart_register_driver(&ar933x_uart_driver); + if (ret) + goto err_out; + + ret = platform_driver_register(&ar933x_uart_platform_driver); + if (ret) + goto err_unregister_uart_driver; + + return 0; + +err_unregister_uart_driver: + uart_unregister_driver(&ar933x_uart_driver); +err_out: + return ret; +} + +static void __exit ar933x_uart_exit(void) +{ + platform_driver_unregister(&ar933x_uart_platform_driver); + uart_unregister_driver(&ar933x_uart_driver); +} + +module_init(ar933x_uart_init); +module_exit(ar933x_uart_exit); + +MODULE_DESCRIPTION("Atheros AR933X UART driver"); +MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:" DRIVER_NAME); |