diff options
Diffstat (limited to 'target/linux/ifxmips/files/drivers/serial/danube_asc.c')
| -rw-r--r-- | target/linux/ifxmips/files/drivers/serial/danube_asc.c | 608 |
1 files changed, 608 insertions, 0 deletions
diff --git a/target/linux/ifxmips/files/drivers/serial/danube_asc.c b/target/linux/ifxmips/files/drivers/serial/danube_asc.c new file mode 100644 index 0000000000..b50b1e7bee --- /dev/null +++ b/target/linux/ifxmips/files/drivers/serial/danube_asc.c @@ -0,0 +1,608 @@ +/* + * Driver for DANUBEASC serial ports + * + * 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 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 + * + * Copyright (C) 2004 Infineon IFAP DC COM CPE + * Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org> + * Copyright (C) 2007 John Crispin <blogic@openwrt.org> + */ + +#include <linux/module.h> +#include <linux/errno.h> +#include <linux/signal.h> +#include <linux/sched.h> +#include <linux/interrupt.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <linux/major.h> +#include <linux/string.h> +#include <linux/fcntl.h> +#include <linux/ptrace.h> +#include <linux/ioport.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/circ_buf.h> +#include <linux/serial.h> +#include <linux/serial_core.h> +#include <linux/console.h> +#include <linux/sysrq.h> +#include <linux/irq.h> + +#include <asm/system.h> +#include <asm/io.h> +#include <asm/uaccess.h> +#include <asm/bitops.h> +#include <asm/danube/danube.h> +#include <asm/danube/danube_irq.h> +#include <asm/danube/danube_serial.h> + +#define PORT_DANUBEASC 111 + +#include <linux/serial_core.h> + +#define UART_DUMMY_UER_RX 1 + +static void danubeasc_tx_chars(struct uart_port *port); +extern void prom_printf(const char * fmt, ...); +static struct uart_port danubeasc_port; +static struct uart_driver danubeasc_reg; +static unsigned int uartclk = 0; +extern unsigned int danube_get_fpi_hz(void); + +static void +danubeasc_stop_tx (struct uart_port *port) +{ + /* fifo underrun shuts up after firing once */ + return; +} + +static void +danubeasc_start_tx (struct uart_port *port) +{ + unsigned long flags; + + local_irq_save(flags); + danubeasc_tx_chars(port); + local_irq_restore(flags); + + return; +} + +static void +danubeasc_stop_rx (struct uart_port *port) +{ + /* clear the RX enable bit */ + writel(ASCWHBSTATE_CLRREN, DANUBE_ASC1_WHBSTATE); +} + +static void +danubeasc_enable_ms (struct uart_port *port) +{ + /* no modem signals */ + return; +} + +static void +danubeasc_rx_chars (struct uart_port *port) +{ + struct tty_struct *tty = port->info->tty; + unsigned int ch = 0, rsr = 0, fifocnt; + + fifocnt = readl(DANUBE_ASC1_FSTAT) & ASCFSTAT_RXFFLMASK; + while (fifocnt--) + { + u8 flag = TTY_NORMAL; + ch = readl(DANUBE_ASC1_RBUF); + rsr = (readl(DANUBE_ASC1_STATE) & ASCSTATE_ANY) | UART_DUMMY_UER_RX; + tty_flip_buffer_push(tty); + port->icount.rx++; + + /* + * Note that the error handling code is + * out of the main execution path + */ + if (rsr & ASCSTATE_ANY) { + if (rsr & ASCSTATE_PE) { + port->icount.parity++; + writel(readl(DANUBE_ASC1_WHBSTATE) | ASCWHBSTATE_CLRPE, DANUBE_ASC1_WHBSTATE); + } else if (rsr & ASCSTATE_FE) { + port->icount.frame++; + writel(readl(DANUBE_ASC1_WHBSTATE) | ASCWHBSTATE_CLRFE, DANUBE_ASC1_WHBSTATE); + } + if (rsr & ASCSTATE_ROE) { + port->icount.overrun++; + writel(readl(DANUBE_ASC1_WHBSTATE) | ASCWHBSTATE_CLRROE, DANUBE_ASC1_WHBSTATE); + } + + rsr &= port->read_status_mask; + + if (rsr & ASCSTATE_PE) + flag = TTY_PARITY; + else if (rsr & ASCSTATE_FE) + flag = TTY_FRAME; + } + + if ((rsr & port->ignore_status_mask) == 0) + tty_insert_flip_char(tty, ch, flag); + + if (rsr & ASCSTATE_ROE) + /* + * Overrun is special, since it's reported + * immediately, and doesn't affect the current + * character + */ + tty_insert_flip_char(tty, 0, TTY_OVERRUN); + } + if (ch != 0) + tty_flip_buffer_push(tty); + + return; +} + + +static void +danubeasc_tx_chars (struct uart_port *port) +{ + struct circ_buf *xmit = &port->info->xmit; + + if (uart_tx_stopped(port)) { + danubeasc_stop_tx(port); + return; + } + + while(((readl(DANUBE_ASC1_FSTAT) & ASCFSTAT_TXFFLMASK) + >> ASCFSTAT_TXFFLOFF) != DANUBEASC_TXFIFO_FULL) + { + if (port->x_char) { + writel(port->x_char, DANUBE_ASC1_TBUF); + port->icount.tx++; + port->x_char = 0; + continue; + } + + if (uart_circ_empty(xmit)) + break; + + writel(port->info->xmit.buf[port->info->xmit.tail], DANUBE_ASC1_TBUF); + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + port->icount.tx++; + } + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(port); +} + +static irqreturn_t +danubeasc_tx_int (int irq, void *port) +{ + writel(ASC_IRNCR_TIR, DANUBE_ASC1_IRNCR); + danubeasc_start_tx(port); + mask_and_ack_danube_irq(irq); + + return IRQ_HANDLED; +} + +static irqreturn_t +danubeasc_er_int (int irq, void *port) +{ + /* clear any pending interrupts */ + writel(readl(DANUBE_ASC1_WHBSTATE) | ASCWHBSTATE_CLRPE | + ASCWHBSTATE_CLRFE | ASCWHBSTATE_CLRROE, DANUBE_ASC1_WHBSTATE); + + return IRQ_HANDLED; +} + +static irqreturn_t +danubeasc_rx_int (int irq, void *port) +{ + writel(ASC_IRNCR_RIR, DANUBE_ASC1_IRNCR); + danubeasc_rx_chars((struct uart_port *) port); + mask_and_ack_danube_irq(irq); + + return IRQ_HANDLED; +} + +static unsigned int +danubeasc_tx_empty (struct uart_port *port) +{ + int status; + + status = readl(DANUBE_ASC1_FSTAT) & ASCFSTAT_TXFFLMASK; + + return status ? 0 : TIOCSER_TEMT; +} + +static unsigned int +danubeasc_get_mctrl (struct uart_port *port) +{ + return TIOCM_CTS | TIOCM_CAR | TIOCM_DSR; +} + +static void +danubeasc_set_mctrl (struct uart_port *port, u_int mctrl) +{ + return; +} + +static void +danubeasc_break_ctl (struct uart_port *port, int break_state) +{ + return; +} + +static void +danubeasc1_hw_init (void) +{ + /* this setup was probably already done in ROM/u-boot but we do it again*/ + /* TODO: GPIO pins are multifunction */ + writel(readl(DANUBE_ASC1_CLC) & ~DANUBE_ASC1_CLC_DISS, DANUBE_ASC1_CLC); + writel((readl(DANUBE_ASC1_CLC) & ~ASCCLC_RMCMASK) | (1 << ASCCLC_RMCOFFSET), DANUBE_ASC1_CLC); + writel(0, DANUBE_ASC1_PISEL); + writel(((DANUBEASC_TXFIFO_FL << ASCTXFCON_TXFITLOFF) & + ASCTXFCON_TXFITLMASK) | ASCTXFCON_TXFEN | ASCTXFCON_TXFFLU, DANUBE_ASC1_TXFCON); + writel(((DANUBEASC_RXFIFO_FL << ASCRXFCON_RXFITLOFF) & + ASCRXFCON_RXFITLMASK) | ASCRXFCON_RXFEN | ASCRXFCON_RXFFLU, DANUBE_ASC1_RXFCON); + wmb (); + + /*framing, overrun, enable */ + writel(readl(DANUBE_ASC1_CON) | ASCCON_M_8ASYNC | ASCCON_FEN | ASCCON_TOEN | ASCCON_ROEN, + DANUBE_ASC1_CON); +} + +static int +danubeasc_startup (struct uart_port *port) +{ + unsigned long flags; + int retval; + + /* this assumes: CON.BRS = CON.FDE = 0 */ + if (uartclk == 0) + uartclk = danube_get_fpi_hz(); + + danubeasc_port.uartclk = uartclk; + + danubeasc1_hw_init(); + + local_irq_save(flags); + + retval = request_irq(DANUBEASC1_RIR, danubeasc_rx_int, IRQF_DISABLED, "asc_rx", port); + if (retval){ + printk("failed to request danubeasc_rx_int\n"); + return retval; + } + + retval = request_irq(DANUBEASC1_TIR, danubeasc_tx_int, IRQF_DISABLED, "asc_tx", port); + if (retval){ + printk("failed to request danubeasc_tx_int\n"); + goto err1; + } + + retval = request_irq(DANUBEASC1_EIR, danubeasc_er_int, IRQF_DISABLED, "asc_er", port); + if (retval){ + printk("failed to request danubeasc_er_int\n"); + goto err2; + } + + writel(ASC_IRNREN_RX_BUF | ASC_IRNREN_TX_BUF | ASC_IRNREN_ERR | ASC_IRNREN_TX, + DANUBE_ASC1_IRNREN); + + local_irq_restore(flags); + + return 0; + +err2: + free_irq(DANUBEASC1_TIR, port); + +err1: + free_irq(DANUBEASC1_RIR, port); + local_irq_restore(flags); + + return retval; +} + +static void +danubeasc_shutdown (struct uart_port *port) +{ + free_irq(DANUBEASC1_RIR, port); + free_irq(DANUBEASC1_TIR, port); + free_irq(DANUBEASC1_EIR, port); + /* + * disable the baudrate generator to disable the ASC + */ + writel(0, DANUBE_ASC1_CON); + + /* flush and then disable the fifos */ + writel(readl(DANUBE_ASC1_RXFCON) | ASCRXFCON_RXFFLU, DANUBE_ASC1_RXFCON); + writel(readl(DANUBE_ASC1_RXFCON) & ~ASCRXFCON_RXFEN, DANUBE_ASC1_RXFCON); + writel(readl(DANUBE_ASC1_TXFCON) | ASCTXFCON_TXFFLU, DANUBE_ASC1_TXFCON); + writel(readl(DANUBE_ASC1_TXFCON) & ~ASCTXFCON_TXFEN, DANUBE_ASC1_TXFCON); +} + +static void danubeasc_set_termios(struct uart_port *port, struct ktermios *new, struct ktermios *old) +{ + unsigned int cflag; + unsigned int iflag; + unsigned int quot; + unsigned int baud; + unsigned int con = 0; + unsigned long flags; + + cflag = new->c_cflag; + iflag = new->c_iflag; + + /* byte size and parity */ + switch (cflag & CSIZE) { + case CS7: + con = ASCCON_M_7ASYNC; + break; + + case CS5: + case CS6: + default: + con = ASCCON_M_8ASYNC; + break; + } + + if (cflag & CSTOPB) + con |= ASCCON_STP; + + if (cflag & PARENB) { + if (!(cflag & PARODD)) + con &= ~ASCCON_ODD; + else + con |= ASCCON_ODD; + } + + port->read_status_mask = ASCSTATE_ROE; + if (iflag & INPCK) + port->read_status_mask |= ASCSTATE_FE | ASCSTATE_PE; + + port->ignore_status_mask = 0; + if (iflag & IGNPAR) + port->ignore_status_mask |= ASCSTATE_FE | ASCSTATE_PE; + + if (iflag & IGNBRK) { + /* + * If we're ignoring parity and break indicators, + * ignore overruns too (for real raw support). + */ + if (iflag & IGNPAR) + port->ignore_status_mask |= ASCSTATE_ROE; + } + + if ((cflag & CREAD) == 0) + port->ignore_status_mask |= UART_DUMMY_UER_RX; + + /* set error signals - framing, parity and overrun, enable receiver */ + con |= ASCCON_FEN | ASCCON_TOEN | ASCCON_ROEN; + + local_irq_save(flags); + + /* set up CON */ + writel(readl(DANUBE_ASC1_CON) | con, DANUBE_ASC1_CON); + + /* Set baud rate - take a divider of 2 into account */ + baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16); + quot = uart_get_divisor(port, baud); + quot = quot / 2 - 1; + + /* disable the baudrate generator */ + writel(readl(DANUBE_ASC1_CON) & ~ASCCON_R, DANUBE_ASC1_CON); + + /* make sure the fractional divider is off */ + writel(readl(DANUBE_ASC1_CON) & ~ASCCON_FDE, DANUBE_ASC1_CON); + + /* set up to use divisor of 2 */ + writel(readl(DANUBE_ASC1_CON) & ~ASCCON_BRS, DANUBE_ASC1_CON); + + /* now we can write the new baudrate into the register */ + writel(quot, DANUBE_ASC1_BG); + + /* turn the baudrate generator back on */ + writel(readl(DANUBE_ASC1_CON) | ASCCON_R, DANUBE_ASC1_CON); + + /* enable rx */ + writel(ASCWHBSTATE_SETREN, DANUBE_ASC1_WHBSTATE); + + local_irq_restore(flags); +} + +static const char* +danubeasc_type (struct uart_port *port) +{ + return port->type == PORT_DANUBEASC ? "DANUBEASC" : NULL; +} + +static void +danubeasc_release_port (struct uart_port *port) +{ + return; +} + +static int +danubeasc_request_port (struct uart_port *port) +{ + return 0; +} + +static void +danubeasc_config_port (struct uart_port *port, int flags) +{ + if (flags & UART_CONFIG_TYPE) { + port->type = PORT_DANUBEASC; + danubeasc_request_port(port); + } +} + +static int +danubeasc_verify_port (struct uart_port *port, struct serial_struct *ser) +{ + int ret = 0; + if (ser->type != PORT_UNKNOWN && ser->type != PORT_DANUBEASC) + ret = -EINVAL; + if (ser->irq < 0 || ser->irq >= NR_IRQS) + ret = -EINVAL; + if (ser->baud_base < 9600) + ret = -EINVAL; + return ret; +} + +static struct uart_ops danubeasc_pops = { + .tx_empty = danubeasc_tx_empty, + .set_mctrl = danubeasc_set_mctrl, + .get_mctrl = danubeasc_get_mctrl, + .stop_tx = danubeasc_stop_tx, + .start_tx = danubeasc_start_tx, + .stop_rx = danubeasc_stop_rx, + .enable_ms = danubeasc_enable_ms, + .break_ctl = danubeasc_break_ctl, + .startup = danubeasc_startup, + .shutdown = danubeasc_shutdown, + .set_termios = danubeasc_set_termios, + .type = danubeasc_type, + .release_port = danubeasc_release_port, + .request_port = danubeasc_request_port, + .config_port = danubeasc_config_port, + .verify_port = danubeasc_verify_port, +}; + +static struct uart_port danubeasc_port = { + membase: (void *)DANUBE_ASC1_BASE_ADDR, + mapbase: DANUBE_ASC1_BASE_ADDR, + iotype: SERIAL_IO_MEM, + irq: DANUBEASC1_RIR, + uartclk: 0, + fifosize: 16, + unused: {DANUBEASC1_TIR, DANUBEASC1_EIR}, + type: PORT_DANUBEASC, + ops: &danubeasc_pops, + flags: ASYNC_BOOT_AUTOCONF, +}; + +static void +danubeasc_console_write (struct console *co, const char *s, u_int count) +{ + int i, fifocnt; + unsigned long flags; + + local_irq_save(flags); + for (i = 0; i < count; i++) + { + /* wait until the FIFO is not full */ + do + { + fifocnt = (readl(DANUBE_ASC1_FSTAT) & ASCFSTAT_TXFFLMASK) + >> ASCFSTAT_TXFFLOFF; + } while (fifocnt == DANUBEASC_TXFIFO_FULL); + + if (s[i] == '\0') + { + break; + } + + if (s[i] == '\n') + { + writel('\r', DANUBE_ASC1_TBUF); + do + { + fifocnt = (readl(DANUBE_ASC1_FSTAT) & ASCFSTAT_TXFFLMASK) + >> ASCFSTAT_TXFFLOFF; + } while (fifocnt == DANUBEASC_TXFIFO_FULL); + } + writel(s[i], DANUBE_ASC1_TBUF); + } + + local_irq_restore(flags); +} + +static int __init +danubeasc_console_setup (struct console *co, char *options) +{ + struct uart_port *port; + int baud = 115200; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + + if (uartclk == 0) + uartclk = danube_get_fpi_hz(); + co->index = 0; + port = &danubeasc_port; + danubeasc_port.uartclk = uartclk; + danubeasc_port.type = PORT_DANUBEASC; + + if (options){ + uart_parse_options(options, &baud, &parity, &bits, &flow); + } + + return uart_set_options(port, co, baud, parity, bits, flow); +} + +static struct uart_driver danubeasc_reg; +static struct console danubeasc_console = { + name: "ttyS", + write: danubeasc_console_write, + device: uart_console_device, + setup: danubeasc_console_setup, + flags: CON_PRINTBUFFER, + index: -1, + data: &danubeasc_reg, +}; + +static int __init +danubeasc_console_init (void) +{ + register_console(&danubeasc_console); + return 0; +} +console_initcall(danubeasc_console_init); + +static struct uart_driver danubeasc_reg = { + .owner = THIS_MODULE, + .driver_name = "serial", + .dev_name = "ttyS", + .major = TTY_MAJOR, + .minor = 64, + .nr = 1, + .cons = &danubeasc_console, +}; + +static int __init +danubeasc_init (void) +{ + unsigned char res; + + uart_register_driver(&danubeasc_reg); + res = uart_add_one_port(&danubeasc_reg, &danubeasc_port); + + return res; +} + +static void __exit +danubeasc_exit (void) +{ + uart_unregister_driver(&danubeasc_reg); +} + +module_init(danubeasc_init); +module_exit(danubeasc_exit); + +MODULE_AUTHOR("John Crispin <blogic@openwrt.org>"); +MODULE_DESCRIPTION("MIPS Danube serial port driver"); +MODULE_LICENSE("GPL"); |