diff options
Diffstat (limited to 'drivers/tty/serial/clps711x.c')
| -rw-r--r-- | drivers/tty/serial/clps711x.c | 579 |
1 files changed, 579 insertions, 0 deletions
diff --git a/drivers/tty/serial/clps711x.c b/drivers/tty/serial/clps711x.c new file mode 100644 index 000000000000..b6acd19b458e --- /dev/null +++ b/drivers/tty/serial/clps711x.c @@ -0,0 +1,579 @@ +/* + * linux/drivers/char/clps711x.c + * + * Driver for CLPS711x serial ports + * + * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. + * + * Copyright 1999 ARM Limited + * Copyright (C) 2000 Deep Blue Solutions Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#if defined(CONFIG_SERIAL_CLPS711X_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) +#define SUPPORT_SYSRQ +#endif + +#include <linux/module.h> +#include <linux/ioport.h> +#include <linux/init.h> +#include <linux/console.h> +#include <linux/sysrq.h> +#include <linux/spinlock.h> +#include <linux/device.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <linux/serial_core.h> +#include <linux/serial.h> +#include <linux/io.h> + +#include <mach/hardware.h> +#include <asm/irq.h> +#include <asm/hardware/clps7111.h> + +#define UART_NR 2 + +#define SERIAL_CLPS711X_MAJOR 204 +#define SERIAL_CLPS711X_MINOR 40 +#define SERIAL_CLPS711X_NR UART_NR + +/* + * We use the relevant SYSCON register as a base address for these ports. + */ +#define UBRLCR(port) ((port)->iobase + UBRLCR1 - SYSCON1) +#define UARTDR(port) ((port)->iobase + UARTDR1 - SYSCON1) +#define SYSFLG(port) ((port)->iobase + SYSFLG1 - SYSCON1) +#define SYSCON(port) ((port)->iobase + SYSCON1 - SYSCON1) + +#define TX_IRQ(port) ((port)->irq) +#define RX_IRQ(port) ((port)->irq + 1) + +#define UART_ANY_ERR (UARTDR_FRMERR | UARTDR_PARERR | UARTDR_OVERR) + +#define tx_enabled(port) ((port)->unused[0]) + +static void clps711xuart_stop_tx(struct uart_port *port) +{ + if (tx_enabled(port)) { + disable_irq(TX_IRQ(port)); + tx_enabled(port) = 0; + } +} + +static void clps711xuart_start_tx(struct uart_port *port) +{ + if (!tx_enabled(port)) { + enable_irq(TX_IRQ(port)); + tx_enabled(port) = 1; + } +} + +static void clps711xuart_stop_rx(struct uart_port *port) +{ + disable_irq(RX_IRQ(port)); +} + +static void clps711xuart_enable_ms(struct uart_port *port) +{ +} + +static irqreturn_t clps711xuart_int_rx(int irq, void *dev_id) +{ + struct uart_port *port = dev_id; + struct tty_struct *tty = port->state->port.tty; + unsigned int status, ch, flg; + + status = clps_readl(SYSFLG(port)); + while (!(status & SYSFLG_URXFE)) { + ch = clps_readl(UARTDR(port)); + + port->icount.rx++; + + flg = TTY_NORMAL; + + /* + * Note that the error handling code is + * out of the main execution path + */ + if (unlikely(ch & UART_ANY_ERR)) { + if (ch & UARTDR_PARERR) + port->icount.parity++; + else if (ch & UARTDR_FRMERR) + port->icount.frame++; + if (ch & UARTDR_OVERR) + port->icount.overrun++; + + ch &= port->read_status_mask; + + if (ch & UARTDR_PARERR) + flg = TTY_PARITY; + else if (ch & UARTDR_FRMERR) + flg = TTY_FRAME; + +#ifdef SUPPORT_SYSRQ + port->sysrq = 0; +#endif + } + + if (uart_handle_sysrq_char(port, ch)) + goto ignore_char; + + /* + * CHECK: does overrun affect the current character? + * ASSUMPTION: it does not. + */ + uart_insert_char(port, ch, UARTDR_OVERR, ch, flg); + + ignore_char: + status = clps_readl(SYSFLG(port)); + } + tty_flip_buffer_push(tty); + return IRQ_HANDLED; +} + +static irqreturn_t clps711xuart_int_tx(int irq, void *dev_id) +{ + struct uart_port *port = dev_id; + struct circ_buf *xmit = &port->state->xmit; + int count; + + if (port->x_char) { + clps_writel(port->x_char, UARTDR(port)); + port->icount.tx++; + port->x_char = 0; + return IRQ_HANDLED; + } + if (uart_circ_empty(xmit) || uart_tx_stopped(port)) { + clps711xuart_stop_tx(port); + return IRQ_HANDLED; + } + + count = port->fifosize >> 1; + do { + clps_writel(xmit->buf[xmit->tail], UARTDR(port)); + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + port->icount.tx++; + if (uart_circ_empty(xmit)) + break; + } while (--count > 0); + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(port); + + if (uart_circ_empty(xmit)) + clps711xuart_stop_tx(port); + + return IRQ_HANDLED; +} + +static unsigned int clps711xuart_tx_empty(struct uart_port *port) +{ + unsigned int status = clps_readl(SYSFLG(port)); + return status & SYSFLG_UBUSY ? 0 : TIOCSER_TEMT; +} + +static unsigned int clps711xuart_get_mctrl(struct uart_port *port) +{ + unsigned int port_addr; + unsigned int result = 0; + unsigned int status; + + port_addr = SYSFLG(port); + if (port_addr == SYSFLG1) { + status = clps_readl(SYSFLG1); + if (status & SYSFLG1_DCD) + result |= TIOCM_CAR; + if (status & SYSFLG1_DSR) + result |= TIOCM_DSR; + if (status & SYSFLG1_CTS) + result |= TIOCM_CTS; + } + + return result; +} + +static void +clps711xuart_set_mctrl_null(struct uart_port *port, unsigned int mctrl) +{ +} + +static void clps711xuart_break_ctl(struct uart_port *port, int break_state) +{ + unsigned long flags; + unsigned int ubrlcr; + + spin_lock_irqsave(&port->lock, flags); + ubrlcr = clps_readl(UBRLCR(port)); + if (break_state == -1) + ubrlcr |= UBRLCR_BREAK; + else + ubrlcr &= ~UBRLCR_BREAK; + clps_writel(ubrlcr, UBRLCR(port)); + spin_unlock_irqrestore(&port->lock, flags); +} + +static int clps711xuart_startup(struct uart_port *port) +{ + unsigned int syscon; + int retval; + + tx_enabled(port) = 1; + + /* + * Allocate the IRQs + */ + retval = request_irq(TX_IRQ(port), clps711xuart_int_tx, 0, + "clps711xuart_tx", port); + if (retval) + return retval; + + retval = request_irq(RX_IRQ(port), clps711xuart_int_rx, 0, + "clps711xuart_rx", port); + if (retval) { + free_irq(TX_IRQ(port), port); + return retval; + } + + /* + * enable the port + */ + syscon = clps_readl(SYSCON(port)); + syscon |= SYSCON_UARTEN; + clps_writel(syscon, SYSCON(port)); + + return 0; +} + +static void clps711xuart_shutdown(struct uart_port *port) +{ + unsigned int ubrlcr, syscon; + + /* + * Free the interrupt + */ + free_irq(TX_IRQ(port), port); /* TX interrupt */ + free_irq(RX_IRQ(port), port); /* RX interrupt */ + + /* + * disable the port + */ + syscon = clps_readl(SYSCON(port)); + syscon &= ~SYSCON_UARTEN; + clps_writel(syscon, SYSCON(port)); + + /* + * disable break condition and fifos + */ + ubrlcr = clps_readl(UBRLCR(port)); + ubrlcr &= ~(UBRLCR_FIFOEN | UBRLCR_BREAK); + clps_writel(ubrlcr, UBRLCR(port)); +} + +static void +clps711xuart_set_termios(struct uart_port *port, struct ktermios *termios, + struct ktermios *old) +{ + unsigned int ubrlcr, baud, quot; + unsigned long flags; + + /* + * We don't implement CREAD. + */ + termios->c_cflag |= CREAD; + + /* + * Ask the core to calculate the divisor for us. + */ + baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16); + quot = uart_get_divisor(port, baud); + + switch (termios->c_cflag & CSIZE) { + case CS5: + ubrlcr = UBRLCR_WRDLEN5; + break; + case CS6: + ubrlcr = UBRLCR_WRDLEN6; + break; + case CS7: + ubrlcr = UBRLCR_WRDLEN7; + break; + default: // CS8 + ubrlcr = UBRLCR_WRDLEN8; + break; + } + if (termios->c_cflag & CSTOPB) + ubrlcr |= UBRLCR_XSTOP; + if (termios->c_cflag & PARENB) { + ubrlcr |= UBRLCR_PRTEN; + if (!(termios->c_cflag & PARODD)) + ubrlcr |= UBRLCR_EVENPRT; + } + if (port->fifosize > 1) + ubrlcr |= UBRLCR_FIFOEN; + + spin_lock_irqsave(&port->lock, flags); + + /* + * Update the per-port timeout. + */ + uart_update_timeout(port, termios->c_cflag, baud); + + port->read_status_mask = UARTDR_OVERR; + if (termios->c_iflag & INPCK) + port->read_status_mask |= UARTDR_PARERR | UARTDR_FRMERR; + + /* + * Characters to ignore + */ + port->ignore_status_mask = 0; + if (termios->c_iflag & IGNPAR) + port->ignore_status_mask |= UARTDR_FRMERR | UARTDR_PARERR; + if (termios->c_iflag & IGNBRK) { + /* + * If we're ignoring parity and break indicators, + * ignore overruns to (for real raw support). + */ + if (termios->c_iflag & IGNPAR) + port->ignore_status_mask |= UARTDR_OVERR; + } + + quot -= 1; + + clps_writel(ubrlcr | quot, UBRLCR(port)); + + spin_unlock_irqrestore(&port->lock, flags); +} + +static const char *clps711xuart_type(struct uart_port *port) +{ + return port->type == PORT_CLPS711X ? "CLPS711x" : NULL; +} + +/* + * Configure/autoconfigure the port. + */ +static void clps711xuart_config_port(struct uart_port *port, int flags) +{ + if (flags & UART_CONFIG_TYPE) + port->type = PORT_CLPS711X; +} + +static void clps711xuart_release_port(struct uart_port *port) +{ +} + +static int clps711xuart_request_port(struct uart_port *port) +{ + return 0; +} + +static struct uart_ops clps711x_pops = { + .tx_empty = clps711xuart_tx_empty, + .set_mctrl = clps711xuart_set_mctrl_null, + .get_mctrl = clps711xuart_get_mctrl, + .stop_tx = clps711xuart_stop_tx, + .start_tx = clps711xuart_start_tx, + .stop_rx = clps711xuart_stop_rx, + .enable_ms = clps711xuart_enable_ms, + .break_ctl = clps711xuart_break_ctl, + .startup = clps711xuart_startup, + .shutdown = clps711xuart_shutdown, + .set_termios = clps711xuart_set_termios, + .type = clps711xuart_type, + .config_port = clps711xuart_config_port, + .release_port = clps711xuart_release_port, + .request_port = clps711xuart_request_port, +}; + +static struct uart_port clps711x_ports[UART_NR] = { + { + .iobase = SYSCON1, + .irq = IRQ_UTXINT1, /* IRQ_URXINT1, IRQ_UMSINT */ + .uartclk = 3686400, + .fifosize = 16, + .ops = &clps711x_pops, + .line = 0, + .flags = UPF_BOOT_AUTOCONF, + }, + { + .iobase = SYSCON2, + .irq = IRQ_UTXINT2, /* IRQ_URXINT2 */ + .uartclk = 3686400, + .fifosize = 16, + .ops = &clps711x_pops, + .line = 1, + .flags = UPF_BOOT_AUTOCONF, + } +}; + +#ifdef CONFIG_SERIAL_CLPS711X_CONSOLE +static void clps711xuart_console_putchar(struct uart_port *port, int ch) +{ + while (clps_readl(SYSFLG(port)) & SYSFLG_UTXFF) + barrier(); + clps_writel(ch, UARTDR(port)); +} + +/* + * Print a string to the serial port trying not to disturb + * any possible real use of the port... + * + * The console_lock must be held when we get here. + * + * Note that this is called with interrupts already disabled + */ +static void +clps711xuart_console_write(struct console *co, const char *s, + unsigned int count) +{ + struct uart_port *port = clps711x_ports + co->index; + unsigned int status, syscon; + + /* + * Ensure that the port is enabled. + */ + syscon = clps_readl(SYSCON(port)); + clps_writel(syscon | SYSCON_UARTEN, SYSCON(port)); + + uart_console_write(port, s, count, clps711xuart_console_putchar); + + /* + * Finally, wait for transmitter to become empty + * and restore the uart state. + */ + do { + status = clps_readl(SYSFLG(port)); + } while (status & SYSFLG_UBUSY); + + clps_writel(syscon, SYSCON(port)); +} + +static void __init +clps711xuart_console_get_options(struct uart_port *port, int *baud, + int *parity, int *bits) +{ + if (clps_readl(SYSCON(port)) & SYSCON_UARTEN) { + unsigned int ubrlcr, quot; + + ubrlcr = clps_readl(UBRLCR(port)); + + *parity = 'n'; + if (ubrlcr & UBRLCR_PRTEN) { + if (ubrlcr & UBRLCR_EVENPRT) + *parity = 'e'; + else + *parity = 'o'; + } + + if ((ubrlcr & UBRLCR_WRDLEN_MASK) == UBRLCR_WRDLEN7) + *bits = 7; + else + *bits = 8; + + quot = ubrlcr & UBRLCR_BAUD_MASK; + *baud = port->uartclk / (16 * (quot + 1)); + } +} + +static int __init clps711xuart_console_setup(struct console *co, char *options) +{ + struct uart_port *port; + int baud = 38400; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + + /* + * Check whether an invalid uart number has been specified, and + * if so, search for the first available port that does have + * console support. + */ + port = uart_get_console(clps711x_ports, UART_NR, co); + + if (options) + uart_parse_options(options, &baud, &parity, &bits, &flow); + else + clps711xuart_console_get_options(port, &baud, &parity, &bits); + + return uart_set_options(port, co, baud, parity, bits, flow); +} + +static struct uart_driver clps711x_reg; +static struct console clps711x_console = { + .name = "ttyCL", + .write = clps711xuart_console_write, + .device = uart_console_device, + .setup = clps711xuart_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &clps711x_reg, +}; + +static int __init clps711xuart_console_init(void) +{ + register_console(&clps711x_console); + return 0; +} +console_initcall(clps711xuart_console_init); + +#define CLPS711X_CONSOLE &clps711x_console +#else +#define CLPS711X_CONSOLE NULL +#endif + +static struct uart_driver clps711x_reg = { + .driver_name = "ttyCL", + .dev_name = "ttyCL", + .major = SERIAL_CLPS711X_MAJOR, + .minor = SERIAL_CLPS711X_MINOR, + .nr = UART_NR, + + .cons = CLPS711X_CONSOLE, +}; + +static int __init clps711xuart_init(void) +{ + int ret, i; + + printk(KERN_INFO "Serial: CLPS711x driver\n"); + + ret = uart_register_driver(&clps711x_reg); + if (ret) + return ret; + + for (i = 0; i < UART_NR; i++) + uart_add_one_port(&clps711x_reg, &clps711x_ports[i]); + + return 0; +} + +static void __exit clps711xuart_exit(void) +{ + int i; + + for (i = 0; i < UART_NR; i++) + uart_remove_one_port(&clps711x_reg, &clps711x_ports[i]); + + uart_unregister_driver(&clps711x_reg); +} + +module_init(clps711xuart_init); +module_exit(clps711xuart_exit); + +MODULE_AUTHOR("Deep Blue Solutions Ltd"); +MODULE_DESCRIPTION("CLPS-711x generic serial driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_CHARDEV(SERIAL_CLPS711X_MAJOR, SERIAL_CLPS711X_MINOR); |