diff options
Diffstat (limited to 'drivers/serial/serial_lh7a40x.c')
| -rw-r--r-- | drivers/serial/serial_lh7a40x.c | 711 |
1 files changed, 711 insertions, 0 deletions
diff --git a/drivers/serial/serial_lh7a40x.c b/drivers/serial/serial_lh7a40x.c new file mode 100644 index 00000000000..4ce3a41f161 --- /dev/null +++ b/drivers/serial/serial_lh7a40x.c @@ -0,0 +1,711 @@ +/* drivers/serial/serial_lh7a40x.c + * + * Copyright (C) 2004 Coastal Environmental Systems + * + * 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. + * + */ + +/* Driver for Sharp LH7A40X embedded serial ports + * + * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. + * Based on drivers/serial/amba.c, by Deep Blue Solutions Ltd. + * + * --- + * + * This driver supports the embedded UARTs of the Sharp LH7A40X series + * CPUs. While similar to the 16550 and other UART chips, there is + * nothing close to register compatibility. Moreover, some of the + * modem control lines are not available, either in the chip or they + * are lacking in the board-level implementation. + * + * - Use of SIRDIS + * For simplicity, we disable the IR functions of any UART whenever + * we enable it. + * + */ + +#include <linux/config.h> + +#if defined(CONFIG_SERIAL_LH7A40X_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/tty.h> +#include <linux/tty_flip.h> +#include <linux/serial_core.h> +#include <linux/serial.h> + +#include <asm/io.h> +#include <asm/irq.h> + +#define DEV_MAJOR 204 +#define DEV_MINOR 16 +#define DEV_NR 3 + +#define ISR_LOOP_LIMIT 256 + +#define UR(p,o) _UR ((p)->membase, o) +#define _UR(b,o) (*((volatile unsigned int*)(((unsigned char*) b) + (o)))) +#define BIT_CLR(p,o,m) UR(p,o) = UR(p,o) & (~(unsigned int)m) +#define BIT_SET(p,o,m) UR(p,o) = UR(p,o) | ( (unsigned int)m) + +#define UART_REG_SIZE 32 + +#define UART_R_DATA (0x00) +#define UART_R_FCON (0x04) +#define UART_R_BRCON (0x08) +#define UART_R_CON (0x0c) +#define UART_R_STATUS (0x10) +#define UART_R_RAWISR (0x14) +#define UART_R_INTEN (0x18) +#define UART_R_ISR (0x1c) + +#define UARTEN (0x01) /* UART enable */ +#define SIRDIS (0x02) /* Serial IR disable (UART1 only) */ + +#define RxEmpty (0x10) +#define TxEmpty (0x80) +#define TxFull (0x20) +#define nRxRdy RxEmpty +#define nTxRdy TxFull +#define TxBusy (0x08) + +#define RxBreak (0x0800) +#define RxOverrunError (0x0400) +#define RxParityError (0x0200) +#define RxFramingError (0x0100) +#define RxError (RxBreak | RxOverrunError | RxParityError | RxFramingError) + +#define DCD (0x04) +#define DSR (0x02) +#define CTS (0x01) + +#define RxInt (0x01) +#define TxInt (0x02) +#define ModemInt (0x04) +#define RxTimeoutInt (0x08) + +#define MSEOI (0x10) + +#define WLEN_8 (0x60) +#define WLEN_7 (0x40) +#define WLEN_6 (0x20) +#define WLEN_5 (0x00) +#define WLEN (0x60) /* Mask for all word-length bits */ +#define STP2 (0x08) +#define PEN (0x02) /* Parity Enable */ +#define EPS (0x04) /* Even Parity Set */ +#define FEN (0x10) /* FIFO Enable */ +#define BRK (0x01) /* Send Break */ + + +struct uart_port_lh7a40x { + struct uart_port port; + unsigned int statusPrev; /* Most recently read modem status */ +}; + +static void lh7a40xuart_stop_tx (struct uart_port* port, unsigned int tty_stop) +{ + BIT_CLR (port, UART_R_INTEN, TxInt); +} + +static void lh7a40xuart_start_tx (struct uart_port* port, + unsigned int tty_start) +{ + BIT_SET (port, UART_R_INTEN, TxInt); + + /* *** FIXME: do I need to check for startup of the + transmitter? The old driver did, but AMBA + doesn't . */ +} + +static void lh7a40xuart_stop_rx (struct uart_port* port) +{ + BIT_SET (port, UART_R_INTEN, RxTimeoutInt | RxInt); +} + +static void lh7a40xuart_enable_ms (struct uart_port* port) +{ + BIT_SET (port, UART_R_INTEN, ModemInt); +} + +static void +#ifdef SUPPORT_SYSRQ +lh7a40xuart_rx_chars (struct uart_port* port, struct pt_regs* regs) +#else +lh7a40xuart_rx_chars (struct uart_port* port) +#endif +{ + struct tty_struct* tty = port->info->tty; + int cbRxMax = 256; /* (Gross) limit on receive */ + unsigned int data, flag;/* Received data and status */ + + while (!(UR (port, UART_R_STATUS) & nRxRdy) && --cbRxMax) { + if (tty->flip.count >= TTY_FLIPBUF_SIZE) { + if (tty->low_latency) + tty_flip_buffer_push(tty); + /* + * If this failed then we will throw away the + * bytes but must do so to clear interrupts + */ + } + + data = UR (port, UART_R_DATA); + flag = TTY_NORMAL; + ++port->icount.rx; + + if (data & RxError) { /* Quick check, short-circuit */ + if (data & RxBreak) { + data &= ~(RxFramingError | RxParityError); + ++port->icount.brk; + if (uart_handle_break (port)) + continue; + } + else if (data & RxParityError) + ++port->icount.parity; + else if (data & RxFramingError) + ++port->icount.frame; + if (data & RxOverrunError) + ++port->icount.overrun; + + /* Mask by termios, leave Rx'd byte */ + data &= port->read_status_mask | 0xff; + + if (data & RxBreak) + flag = TTY_BREAK; + else if (data & RxParityError) + flag = TTY_PARITY; + else if (data & RxFramingError) + flag = TTY_FRAME; + } + + if (uart_handle_sysrq_char (port, (unsigned char) data, regs)) + continue; + + if ((data & port->ignore_status_mask) == 0) { + tty_insert_flip_char(tty, data, flag); + } + if ((data & RxOverrunError) + && tty->flip.count < TTY_FLIPBUF_SIZE) { + /* + * Overrun is special, since it's reported + * immediately, and doesn't affect the current + * character + */ + tty_insert_flip_char(tty, 0, TTY_OVERRUN); + } + } + tty_flip_buffer_push (tty); + return; +} + +static void lh7a40xuart_tx_chars (struct uart_port* port) +{ + struct circ_buf* xmit = &port->info->xmit; + int cbTxMax = port->fifosize; + + if (port->x_char) { + UR (port, UART_R_DATA) = port->x_char; + ++port->icount.tx; + port->x_char = 0; + return; + } + if (uart_circ_empty (xmit) || uart_tx_stopped (port)) { + lh7a40xuart_stop_tx (port, 0); + return; + } + + /* Unlike the AMBA UART, the lh7a40x UART does not guarantee + that at least half of the FIFO is empty. Instead, we check + status for every character. Using the AMBA method causes + the transmitter to drop characters. */ + + do { + UR (port, UART_R_DATA) = xmit->buf[xmit->tail]; + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + ++port->icount.tx; + if (uart_circ_empty(xmit)) + break; + } while (!(UR (port, UART_R_STATUS) & nTxRdy) + && cbTxMax--); + + if (uart_circ_chars_pending (xmit) < WAKEUP_CHARS) + uart_write_wakeup (port); + + if (uart_circ_empty (xmit)) + lh7a40xuart_stop_tx (port, 0); +} + +static void lh7a40xuart_modem_status (struct uart_port* port) +{ + unsigned int status = UR (port, UART_R_STATUS); + unsigned int delta + = status ^ ((struct uart_port_lh7a40x*) port)->statusPrev; + + BIT_SET (port, UART_R_RAWISR, MSEOI); /* Clear modem status intr */ + + if (!delta) /* Only happens if we missed 2 transitions */ + return; + + ((struct uart_port_lh7a40x*) port)->statusPrev = status; + + if (delta & DCD) + uart_handle_dcd_change (port, status & DCD); + + if (delta & DSR) + ++port->icount.dsr; + + if (delta & CTS) + uart_handle_cts_change (port, status & CTS); + + wake_up_interruptible (&port->info->delta_msr_wait); +} + +static irqreturn_t lh7a40xuart_int (int irq, void* dev_id, + struct pt_regs* regs) +{ + struct uart_port* port = dev_id; + unsigned int cLoopLimit = ISR_LOOP_LIMIT; + unsigned int isr = UR (port, UART_R_ISR); + + + do { + if (isr & (RxInt | RxTimeoutInt)) +#ifdef SUPPORT_SYSRQ + lh7a40xuart_rx_chars(port, regs); +#else + lh7a40xuart_rx_chars(port); +#endif + if (isr & ModemInt) + lh7a40xuart_modem_status (port); + if (isr & TxInt) + lh7a40xuart_tx_chars (port); + + if (--cLoopLimit == 0) + break; + + isr = UR (port, UART_R_ISR); + } while (isr & (RxInt | TxInt | RxTimeoutInt)); + + return IRQ_HANDLED; +} + +static unsigned int lh7a40xuart_tx_empty (struct uart_port* port) +{ + return (UR (port, UART_R_STATUS) & TxEmpty) ? TIOCSER_TEMT : 0; +} + +static unsigned int lh7a40xuart_get_mctrl (struct uart_port* port) +{ + unsigned int result = 0; + unsigned int status = UR (port, UART_R_STATUS); + + if (status & DCD) + result |= TIOCM_CAR; + if (status & DSR) + result |= TIOCM_DSR; + if (status & CTS) + result |= TIOCM_CTS; + + return result; +} + +static void lh7a40xuart_set_mctrl (struct uart_port* port, unsigned int mctrl) +{ + /* None of the ports supports DTR. UART1 supports RTS through GPIO. */ + /* Note, kernel appears to be setting DTR and RTS on console. */ + + /* *** FIXME: this deserves more work. There's some work in + tracing all of the IO pins. */ +#if 0 + if( port->mapbase == UART1_PHYS) { + gpioRegs_t *gpio = (gpioRegs_t *)IO_ADDRESS(GPIO_PHYS); + + if (mctrl & TIOCM_RTS) + gpio->pbdr &= ~GPIOB_UART1_RTS; + else + gpio->pbdr |= GPIOB_UART1_RTS; + } +#endif +} + +static void lh7a40xuart_break_ctl (struct uart_port* port, int break_state) +{ + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + if (break_state == -1) + BIT_SET (port, UART_R_FCON, BRK); /* Assert break */ + else + BIT_CLR (port, UART_R_FCON, BRK); /* Deassert break */ + spin_unlock_irqrestore(&port->lock, flags); +} + +static int lh7a40xuart_startup (struct uart_port* port) +{ + int retval; + + retval = request_irq (port->irq, lh7a40xuart_int, 0, + "serial_lh7a40x", port); + if (retval) + return retval; + + /* Initial modem control-line settings */ + ((struct uart_port_lh7a40x*) port)->statusPrev + = UR (port, UART_R_STATUS); + + /* There is presently no configuration option to enable IR. + Thus, we always disable it. */ + + BIT_SET (port, UART_R_CON, UARTEN | SIRDIS); + BIT_SET (port, UART_R_INTEN, RxTimeoutInt | RxInt); + + return 0; +} + +static void lh7a40xuart_shutdown (struct uart_port* port) +{ + free_irq (port->irq, port); + BIT_CLR (port, UART_R_FCON, BRK | FEN); + BIT_CLR (port, UART_R_CON, UARTEN); +} + +static void lh7a40xuart_set_termios (struct uart_port* port, + struct termios* termios, + struct termios* old) +{ + unsigned int con; + unsigned int inten; + unsigned int fcon; + unsigned long flags; + unsigned int baud; + unsigned int quot; + + baud = uart_get_baud_rate (port, termios, old, 8, port->uartclk/16); + quot = uart_get_divisor (port, baud); /* -1 performed elsewhere */ + + switch (termios->c_cflag & CSIZE) { + case CS5: + fcon = WLEN_5; + break; + case CS6: + fcon = WLEN_6; + break; + case CS7: + fcon = WLEN_7; + break; + case CS8: + default: + fcon = WLEN_8; + break; + } + if (termios->c_cflag & CSTOPB) + fcon |= STP2; + if (termios->c_cflag & PARENB) { + fcon |= PEN; + if (!(termios->c_cflag & PARODD)) + fcon |= EPS; + } + if (port->fifosize > 1) + fcon |= FEN; + + spin_lock_irqsave (&port->lock, flags); + + uart_update_timeout (port, termios->c_cflag, baud); + + port->read_status_mask = RxOverrunError; + if (termios->c_iflag & INPCK) + port->read_status_mask |= RxFramingError | RxParityError; + if (termios->c_iflag & (BRKINT | PARMRK)) + port->read_status_mask |= RxBreak; + + /* Figure mask for status we ignore */ + port->ignore_status_mask = 0; + if (termios->c_iflag & IGNPAR) + port->ignore_status_mask |= RxFramingError | RxParityError; + if (termios->c_iflag & IGNBRK) { + port->ignore_status_mask |= RxBreak; + /* Ignore overrun when ignorning parity */ + /* *** FIXME: is this in the right place? */ + if (termios->c_iflag & IGNPAR) + port->ignore_status_mask |= RxOverrunError; + } + + /* Ignore all receive errors when receive disabled */ + if ((termios->c_cflag & CREAD) == 0) + port->ignore_status_mask |= RxError; + + con = UR (port, UART_R_CON); + inten = (UR (port, UART_R_INTEN) & ~ModemInt); + + if (UART_ENABLE_MS (port, termios->c_cflag)) + inten |= ModemInt; + + BIT_CLR (port, UART_R_CON, UARTEN); /* Disable UART */ + UR (port, UART_R_INTEN) = 0; /* Disable interrupts */ + UR (port, UART_R_BRCON) = quot - 1; /* Set baud rate divisor */ + UR (port, UART_R_FCON) = fcon; /* Set FIFO and frame ctrl */ + UR (port, UART_R_INTEN) = inten; /* Enable interrupts */ + UR (port, UART_R_CON) = con; /* Restore UART mode */ + + spin_unlock_irqrestore(&port->lock, flags); +} + +static const char* lh7a40xuart_type (struct uart_port* port) +{ + return port->type == PORT_LH7A40X ? "LH7A40X" : NULL; +} + +static void lh7a40xuart_release_port (struct uart_port* port) +{ + release_mem_region (port->mapbase, UART_REG_SIZE); +} + +static int lh7a40xuart_request_port (struct uart_port* port) +{ + return request_mem_region (port->mapbase, UART_REG_SIZE, + "serial_lh7a40x") != NULL + ? 0 : -EBUSY; +} + +static void lh7a40xuart_config_port (struct uart_port* port, int flags) +{ + if (flags & UART_CONFIG_TYPE) { + port->type = PORT_LH7A40X; + lh7a40xuart_request_port (port); + } +} + +static int lh7a40xuart_verify_port (struct uart_port* port, + struct serial_struct* ser) +{ + int ret = 0; + + if (ser->type != PORT_UNKNOWN && ser->type != PORT_LH7A40X) + ret = -EINVAL; + if (ser->irq < 0 || ser->irq >= NR_IRQS) + ret = -EINVAL; + if (ser->baud_base < 9600) /* *** FIXME: is this true? */ + ret = -EINVAL; + return ret; +} + +static struct uart_ops lh7a40x_uart_ops = { + .tx_empty = lh7a40xuart_tx_empty, + .set_mctrl = lh7a40xuart_set_mctrl, + .get_mctrl = lh7a40xuart_get_mctrl, + .stop_tx = lh7a40xuart_stop_tx, + .start_tx = lh7a40xuart_start_tx, + .stop_rx = lh7a40xuart_stop_rx, + .enable_ms = lh7a40xuart_enable_ms, + .break_ctl = lh7a40xuart_break_ctl, + .startup = lh7a40xuart_startup, + .shutdown = lh7a40xuart_shutdown, + .set_termios = lh7a40xuart_set_termios, + .type = lh7a40xuart_type, + .release_port = lh7a40xuart_release_port, + .request_port = lh7a40xuart_request_port, + .config_port = lh7a40xuart_config_port, + .verify_port = lh7a40xuart_verify_port, +}; + +static struct uart_port_lh7a40x lh7a40x_ports[DEV_NR] = { + { + .port = { + .membase = (void*) io_p2v (UART1_PHYS), + .mapbase = UART1_PHYS, + .iotype = SERIAL_IO_MEM, + .irq = IRQ_UART1INTR, + .uartclk = 14745600/2, + .fifosize = 16, + .ops = &lh7a40x_uart_ops, + .flags = ASYNC_BOOT_AUTOCONF, + .line = 0, + }, + }, + { + .port = { + .membase = (void*) io_p2v (UART2_PHYS), + .mapbase = UART2_PHYS, + .iotype = SERIAL_IO_MEM, + .irq = IRQ_UART2INTR, + .uartclk = 14745600/2, + .fifosize = 16, + .ops = &lh7a40x_uart_ops, + .flags = ASYNC_BOOT_AUTOCONF, + .line = 1, + }, + }, + { + .port = { + .membase = (void*) io_p2v (UART3_PHYS), + .mapbase = UART3_PHYS, + .iotype = SERIAL_IO_MEM, + .irq = IRQ_UART3INTR, + .uartclk = 14745600/2, + .fifosize = 16, + .ops = &lh7a40x_uart_ops, + .flags = ASYNC_BOOT_AUTOCONF, + .line = 2, + }, + }, +}; + +#ifndef CONFIG_SERIAL_LH7A40X_CONSOLE +# define LH7A40X_CONSOLE NULL +#else +# define LH7A40X_CONSOLE &lh7a40x_console + + +static void lh7a40xuart_console_write (struct console* co, + const char* s, + unsigned int count) +{ + struct uart_port* port = &lh7a40x_ports[co->index].port; + unsigned int con = UR (port, UART_R_CON); + unsigned int inten = UR (port, UART_R_INTEN); + + + UR (port, UART_R_INTEN) = 0; /* Disable all interrupts */ + BIT_SET (port, UART_R_CON, UARTEN | SIRDIS); /* Enable UART */ + + for (; count-- > 0; ++s) { + while (UR (port, UART_R_STATUS) & nTxRdy) + ; + UR (port, UART_R_DATA) = *s; + if (*s == '\n') { + while ((UR (port, UART_R_STATUS) & TxBusy)) + ; + UR (port, UART_R_DATA) = '\r'; + } + } + + /* Wait until all characters are sent */ + while (UR (port, UART_R_STATUS) & TxBusy) + ; + + /* Restore control and interrupt mask */ + UR (port, UART_R_CON) = con; + UR (port, UART_R_INTEN) = inten; +} + +static void __init lh7a40xuart_console_get_options (struct uart_port* port, + int* baud, + int* parity, + int* bits) +{ + if (UR (port, UART_R_CON) & UARTEN) { + unsigned int fcon = UR (port, UART_R_FCON); + unsigned int quot = UR (port, UART_R_BRCON) + 1; + + switch (fcon & (PEN | EPS)) { + default: *parity = 'n'; break; + case PEN: *parity = 'o'; break; + case PEN | EPS: *parity = 'e'; break; + } + + switch (fcon & WLEN) { + default: + case WLEN_8: *bits = 8; break; + case WLEN_7: *bits = 7; break; + case WLEN_6: *bits = 6; break; + case WLEN_5: *bits = 5; break; + } + + *baud = port->uartclk/(16*quot); + } +} + +static int __init lh7a40xuart_console_setup (struct console* co, char* options) +{ + struct uart_port* port; + int baud = 38400; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + + if (co->index >= DEV_NR) /* Bounds check on device number */ + co->index = 0; + port = &lh7a40x_ports[co->index].port; + + if (options) + uart_parse_options (options, &baud, &parity, &bits, &flow); + else + lh7a40xuart_console_get_options (port, &baud, &parity, &bits); + + return uart_set_options (port, co, baud, parity, bits, flow); +} + +extern struct uart_driver lh7a40x_reg; +static struct console lh7a40x_console = { + .name = "ttyAM", + .write = lh7a40xuart_console_write, + .device = uart_console_device, + .setup = lh7a40xuart_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &lh7a40x_reg, +}; + +static int __init lh7a40xuart_console_init(void) +{ + register_console (&lh7a40x_console); + return 0; +} + +console_initcall (lh7a40xuart_console_init); + +#endif + +static struct uart_driver lh7a40x_reg = { + .owner = THIS_MODULE, + .driver_name = "ttyAM", + .dev_name = "ttyAM", + .major = DEV_MAJOR, + .minor = DEV_MINOR, + .nr = DEV_NR, + .cons = LH7A40X_CONSOLE, +}; + +static int __init lh7a40xuart_init(void) +{ + int ret; + + printk (KERN_INFO "serial: LH7A40X serial driver\n"); + + ret = uart_register_driver (&lh7a40x_reg); + + if (ret == 0) { + int i; + + for (i = 0; i < DEV_NR; i++) + uart_add_one_port (&lh7a40x_reg, + &lh7a40x_ports[i].port); + } + return ret; +} + +static void __exit lh7a40xuart_exit(void) +{ + int i; + + for (i = 0; i < DEV_NR; i++) + uart_remove_one_port (&lh7a40x_reg, &lh7a40x_ports[i].port); + + uart_unregister_driver (&lh7a40x_reg); +} + +module_init (lh7a40xuart_init); +module_exit (lh7a40xuart_exit); + +MODULE_AUTHOR ("Marc Singer"); +MODULE_DESCRIPTION ("Sharp LH7A40X serial port driver"); +MODULE_LICENSE ("GPL"); |