--- /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);
projects / openwrt / svn-archive / archive.git / blobdiff