| /* |
| * 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); |