+++ /dev/null
-/*
- * 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-ar71xx/ar933x_uart.h>
-#include <asm/mach-ar71xx/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);
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