diff options
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/Kconfig | 23 | ||||
| -rw-r--r-- | drivers/tty/serial/Makefile | 1 | ||||
| -rw-r--r-- | drivers/tty/serial/ar933x_uart.c | 688 |
3 files changed, 712 insertions, 0 deletions
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index f32a2ea70100..aca2386c5ef1 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -1605,4 +1605,27 @@ config SERIAL_XILINX_PS_UART_CONSOLE help Enable a Xilinx PS UART port to be the system console. +config SERIAL_AR933X + bool "AR933X serial port support" + depends on SOC_AR933X + select SERIAL_CORE + help + If you have an Atheros AR933X SOC based board and want to use the + built-in UART of the SoC, say Y to this option. + +config SERIAL_AR933X_CONSOLE + bool "Console on AR933X serial port" + depends on SERIAL_AR933X=y + select SERIAL_CORE_CONSOLE + help + Enable a built-in UART port of the AR933X to be the system console. + +config SERIAL_AR933X_NR_UARTS + int "Maximum number of AR933X serial ports" + depends on SERIAL_AR933X + default "2" + help + Set this to the number of serial ports you want the driver + to support. + endmenu diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile index 07e0494c6830..f5b01f2ce525 100644 --- a/drivers/tty/serial/Makefile +++ b/drivers/tty/serial/Makefile @@ -91,3 +91,4 @@ obj-$(CONFIG_SERIAL_MXS_AUART) += mxs-auart.o obj-$(CONFIG_SERIAL_LANTIQ) += lantiq.o obj-$(CONFIG_SERIAL_XILINX_PS_UART) += xilinx_uartps.o obj-$(CONFIG_SERIAL_SIRFSOC) += sirfsoc_uart.o +obj-$(CONFIG_SERIAL_AR933X) += ar933x_uart.o diff --git a/drivers/tty/serial/ar933x_uart.c b/drivers/tty/serial/ar933x_uart.c new file mode 100644 index 000000000000..e4f60e2b87f3 --- /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); |