diff options
Diffstat (limited to 'target/linux/amazon/files/drivers/tty/serial/amazon_asc.c')
| -rw-r--r-- | target/linux/amazon/files/drivers/tty/serial/amazon_asc.c | 711 |
1 files changed, 711 insertions, 0 deletions
diff --git a/target/linux/amazon/files/drivers/tty/serial/amazon_asc.c b/target/linux/amazon/files/drivers/tty/serial/amazon_asc.c new file mode 100644 index 000000000..bb2dd7222 --- /dev/null +++ b/target/linux/amazon/files/drivers/tty/serial/amazon_asc.c @@ -0,0 +1,711 @@ +/* + * Driver for AMAZONASC serial ports + * + * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. + * Based on drivers/serial/serial_s3c2400.c + * + * 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 <linux/platform_device.h> + +#include <asm/system.h> +#include <asm/io.h> +#include <asm/uaccess.h> +#include <asm/bitops.h> +#include <asm/amazon/amazon.h> +#include <asm/amazon/irq.h> +#include <asm/amazon/serial.h> + +#define PORT_AMAZONASC 111 + +#include <linux/serial_core.h> + +#define UART_NR 1 + +#define UART_DUMMY_UER_RX 1 + +#define SERIAL_AMAZONASC_MAJOR TTY_MAJOR +#define CALLOUT_AMAZONASC_MAJOR TTYAUX_MAJOR +#define SERIAL_AMAZONASC_MINOR 64 +#define SERIAL_AMAZONASC_NR UART_NR + +static void amazonasc_tx_chars(struct uart_port *port); +static struct uart_port amazonasc_ports[UART_NR]; +static struct uart_driver amazonasc_reg; +static unsigned int uartclk = 0; + +static void amazonasc_stop_tx(struct uart_port *port) +{ + /* fifo underrun shuts up after firing once */ + return; +} + +static void amazonasc_start_tx(struct uart_port *port) +{ + unsigned long flags; + + local_irq_save(flags); + amazonasc_tx_chars(port); + local_irq_restore(flags); + + return; +} + +static void amazonasc_stop_rx(struct uart_port *port) +{ + /* clear the RX enable bit */ + amazon_writel(ASCWHBCON_CLRREN, AMAZON_ASC_WHBCON); +} + +static void amazonasc_enable_ms(struct uart_port *port) +{ + /* no modem signals */ + return; +} + +#include <linux/version.h> + +static void +amazonasc_rx_chars(struct uart_port *port) +{ +#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 31)) + struct tty_struct *tty = port->state->port.tty; +#else + struct tty_struct *tty = port->info->port.tty; +#endif + unsigned int ch = 0, rsr = 0, fifocnt; + + fifocnt = amazon_readl(AMAZON_ASC_FSTAT) & ASCFSTAT_RXFFLMASK; + while (fifocnt--) + { + u8 flag = TTY_NORMAL; + ch = amazon_readl(AMAZON_ASC_RBUF); + rsr = (amazon_readl(AMAZON_ASC_CON) & ASCCON_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 & ASCCON_ANY) { + if (rsr & ASCCON_PE) { + port->icount.parity++; + amazon_writel_masked(AMAZON_ASC_WHBCON, ASCWHBCON_CLRPE, ASCWHBCON_CLRPE); + } else if (rsr & ASCCON_FE) { + port->icount.frame++; + amazon_writel_masked(AMAZON_ASC_WHBCON, ASCWHBCON_CLRFE, ASCWHBCON_CLRFE); + } + if (rsr & ASCCON_OE) { + port->icount.overrun++; + amazon_writel_masked(AMAZON_ASC_WHBCON, ASCWHBCON_CLROE, ASCWHBCON_CLROE); + } + + rsr &= port->read_status_mask; + + if (rsr & ASCCON_PE) + flag = TTY_PARITY; + else if (rsr & ASCCON_FE) + flag = TTY_FRAME; + } + + if ((rsr & port->ignore_status_mask) == 0) + tty_insert_flip_char(tty, ch, flag); + + if (rsr & ASCCON_OE) + /* + * 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 amazonasc_tx_chars(struct uart_port *port) +{ +#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 31)) + struct circ_buf *xmit = &port->state->xmit; +#else + struct circ_buf *xmit = &port->info->xmit; +#endif + + if (uart_tx_stopped(port)) { + amazonasc_stop_tx(port); + return; + } + + while (((amazon_readl(AMAZON_ASC_FSTAT) & ASCFSTAT_TXFFLMASK) + >> ASCFSTAT_TXFFLOFF) != AMAZONASC_TXFIFO_FULL) + { + if (port->x_char) { + amazon_writel(port->x_char, AMAZON_ASC_TBUF); + port->icount.tx++; + port->x_char = 0; + continue; + } + + if (uart_circ_empty(xmit)) + break; + + amazon_writel(xmit->buf[xmit->tail], AMAZON_ASC_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 amazonasc_tx_int(int irq, void *port) +{ + amazon_writel(ASC_IRNCR_TIR, AMAZON_ASC_IRNCR1); + amazonasc_start_tx(port); + + /* clear any pending interrupts */ + amazon_writel_masked(AMAZON_ASC_WHBCON, + (ASCWHBCON_CLRPE | ASCWHBCON_CLRFE | ASCWHBCON_CLROE), + (ASCWHBCON_CLRPE | ASCWHBCON_CLRFE | ASCWHBCON_CLROE)); + + return IRQ_HANDLED; +} + +static irqreturn_t amazonasc_er_int(int irq, void *port) +{ + /* clear any pending interrupts */ + amazon_writel_masked(AMAZON_ASC_WHBCON, + (ASCWHBCON_CLRPE | ASCWHBCON_CLRFE | ASCWHBCON_CLROE), + (ASCWHBCON_CLRPE | ASCWHBCON_CLRFE | ASCWHBCON_CLROE)); + + return IRQ_HANDLED; +} + +static irqreturn_t amazonasc_rx_int(int irq, void *port) +{ + amazon_writel(ASC_IRNCR_RIR, AMAZON_ASC_IRNCR1); + amazonasc_rx_chars((struct uart_port *) port); + return IRQ_HANDLED; +} + +static u_int amazonasc_tx_empty(struct uart_port *port) +{ + int status; + + /* + * FSTAT tells exactly how many bytes are in the FIFO. + * The question is whether we really need to wait for all + * 16 bytes to be transmitted before reporting that the + * transmitter is empty. + */ + status = amazon_readl(AMAZON_ASC_FSTAT) & ASCFSTAT_TXFFLMASK; + return status ? 0 : TIOCSER_TEMT; +} + +static u_int amazonasc_get_mctrl(struct uart_port *port) +{ + /* no modem control signals - the readme says to pretend all are set */ + return TIOCM_CTS|TIOCM_CAR|TIOCM_DSR; +} + +static void amazonasc_set_mctrl(struct uart_port *port, u_int mctrl) +{ + /* no modem control - just return */ + return; +} + +static void amazonasc_break_ctl(struct uart_port *port, int break_state) +{ + /* no way to send a break */ + return; +} + +static int amazonasc_startup(struct uart_port *port) +{ + unsigned int con = 0; + unsigned long flags; + int retval; + + /* this assumes: CON.BRS = CON.FDE = 0 */ + if (uartclk == 0) + uartclk = amazon_get_fpi_hz(); + + amazonasc_ports[0].uartclk = uartclk; + + local_irq_save(flags); + + /* this setup was probably already done in u-boot */ + /* ASC and GPIO Port 1 bits 3 and 4 share the same pins + * P1.3 (RX) in, Alternate 10 + * P1.4 (TX) in, Alternate 10 + */ + amazon_writel_masked(AMAZON_GPIO_P1_DIR, 0x18, 0x10); //P1.4 output, P1.3 input + amazon_writel_masked(AMAZON_GPIO_P1_ALTSEL0, 0x18, 0x18); //ALTSETL0 11 + amazon_writel_masked(AMAZON_GPIO_P1_ALTSEL1, 0x18, 0); //ALTSETL1 00 + amazon_writel_masked(AMAZON_GPIO_P1_OD, 0x18, 0x10); + + /* set up the CLC */ + amazon_writel_masked(AMAZON_ASC_CLC, AMAZON_ASC_CLC_DISS, 0); + amazon_writel_masked(AMAZON_ASC_CLC, ASCCLC_RMCMASK, 1 << ASCCLC_RMCOFFSET); + + /* asynchronous mode */ + con = ASCCON_M_8ASYNC | ASCCON_FEN | ASCCON_OEN | ASCCON_PEN; + + /* choose the line - there's only one */ + amazon_writel(0, AMAZON_ASC_PISEL); + amazon_writel(((AMAZONASC_TXFIFO_FL << ASCTXFCON_TXFITLOFF) & ASCTXFCON_TXFITLMASK) | ASCTXFCON_TXFEN | ASCTXFCON_TXFFLU, + AMAZON_ASC_TXFCON); + amazon_writel(((AMAZONASC_RXFIFO_FL << ASCRXFCON_RXFITLOFF) & ASCRXFCON_RXFITLMASK) | ASCRXFCON_RXFEN | ASCRXFCON_RXFFLU, + AMAZON_ASC_RXFCON); + wmb(); + + amazon_writel_masked(AMAZON_ASC_CON, con, con); + + retval = request_irq(AMAZONASC_RIR, amazonasc_rx_int, 0, "asc_rx", port); + if (retval){ + printk("failed to request amazonasc_rx_int\n"); + return retval; + } + retval = request_irq(AMAZONASC_TIR, amazonasc_tx_int, 0, "asc_tx", port); + if (retval){ + printk("failed to request amazonasc_tx_int\n"); + goto err1; + } + + retval = request_irq(AMAZONASC_EIR, amazonasc_er_int, 0, "asc_er", port); + if (retval){ + printk("failed to request amazonasc_er_int\n"); + goto err2; + } + + local_irq_restore(flags); + return 0; + +err2: + free_irq(AMAZONASC_TIR, port); + +err1: + free_irq(AMAZONASC_RIR, port); + local_irq_restore(flags); + return retval; +} + +static void amazonasc_shutdown(struct uart_port *port) +{ + free_irq(AMAZONASC_RIR, port); + free_irq(AMAZONASC_TIR, port); + free_irq(AMAZONASC_EIR, port); + /* + * disable the baudrate generator to disable the ASC + */ + amazon_writel(0, AMAZON_ASC_CON); + + /* flush and then disable the fifos */ + amazon_writel_masked(AMAZON_ASC_RXFCON, ASCRXFCON_RXFFLU, ASCRXFCON_RXFFLU); + amazon_writel_masked(AMAZON_ASC_RXFCON, ASCRXFCON_RXFEN, 0); + amazon_writel_masked(AMAZON_ASC_TXFCON, ASCTXFCON_TXFFLU, ASCTXFCON_TXFFLU); + amazon_writel_masked(AMAZON_ASC_TXFCON, ASCTXFCON_TXFEN, 0); +} + +static void amazonasc_set_termios(struct uart_port *port, struct ktermios *new, struct ktermios *old) +{ + unsigned int cflag; + unsigned int iflag; + unsigned int baud, quot; + unsigned int con = 0; + unsigned long flags; + + cflag = new->c_cflag; + iflag = new->c_iflag; + + /* byte size and parity */ + switch (cflag & CSIZE) { + /* 7 bits are always with parity */ + case CS7: con = ASCCON_M_7ASYNCPAR; break; + /* the ASC only suports 7 and 8 bits */ + case CS5: + case CS6: + default: + if (cflag & PARENB) + con = ASCCON_M_8ASYNCPAR; + else + 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 = ASCCON_OE; + if (iflag & INPCK) + port->read_status_mask |= ASCCON_FE | ASCCON_PE; + + port->ignore_status_mask = 0; + if (iflag & IGNPAR) + port->ignore_status_mask |= ASCCON_FE | ASCCON_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 |= ASCCON_OE; + } + + /* + * Ignore all characters if CREAD is not set. + */ + if ((cflag & CREAD) == 0) + port->ignore_status_mask |= UART_DUMMY_UER_RX; + + /* set error signals - framing, parity and overrun */ + con |= ASCCON_FEN; + con |= ASCCON_OEN; + con |= ASCCON_PEN; + /* enable the receiver */ + con |= ASCCON_REN; + + /* block the IRQs */ + local_irq_save(flags); + + /* set up CON */ + amazon_writel(con, AMAZON_ASC_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; + + /* the next 3 probably already happened when we set CON above */ + /* disable the baudrate generator */ + amazon_writel_masked(AMAZON_ASC_CON, ASCCON_R, 0); + /* make sure the fractional divider is off */ + amazon_writel_masked(AMAZON_ASC_CON, ASCCON_FDE, 0); + /* set up to use divisor of 2 */ + amazon_writel_masked(AMAZON_ASC_CON, ASCCON_BRS, 0); + /* now we can write the new baudrate into the register */ + amazon_writel(quot, AMAZON_ASC_BTR); + /* turn the baudrate generator back on */ + amazon_writel_masked(AMAZON_ASC_CON, ASCCON_R, ASCCON_R); + + local_irq_restore(flags); +} + +static const char *amazonasc_type(struct uart_port *port) +{ + return port->type == PORT_AMAZONASC ? "AMAZONASC" : NULL; +} + +/* + * Release the memory region(s) being used by 'port' + */ +static void amazonasc_release_port(struct uart_port *port) +{ + return; +} + +/* + * Request the memory region(s) being used by 'port' + */ +static int amazonasc_request_port(struct uart_port *port) +{ + return 0; +} + +/* + * Configure/autoconfigure the port. + */ +static void amazonasc_config_port(struct uart_port *port, int flags) +{ + if (flags & UART_CONFIG_TYPE) { + port->type = PORT_AMAZONASC; + amazonasc_request_port(port); + } +} + +/* + * verify the new serial_struct (for TIOCSSERIAL). + */ +static int amazonasc_verify_port(struct uart_port *port, struct serial_struct *ser) +{ + int ret = 0; + if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMAZONASC) + 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 amazonasc_pops = { + .tx_empty = amazonasc_tx_empty, + .set_mctrl = amazonasc_set_mctrl, + .get_mctrl = amazonasc_get_mctrl, + .stop_tx = amazonasc_stop_tx, + .start_tx = amazonasc_start_tx, + .stop_rx = amazonasc_stop_rx, + .enable_ms = amazonasc_enable_ms, + .break_ctl = amazonasc_break_ctl, + .startup = amazonasc_startup, + .shutdown = amazonasc_shutdown, + .set_termios = amazonasc_set_termios, + .type = amazonasc_type, + .release_port = amazonasc_release_port, + .request_port = amazonasc_request_port, + .config_port = amazonasc_config_port, + .verify_port = amazonasc_verify_port, +}; + +static struct uart_port amazonasc_ports[UART_NR] = { + { + membase: (void *)AMAZON_ASC, + mapbase: AMAZON_ASC, + iotype: SERIAL_IO_MEM, + irq: AMAZONASC_RIR, /* RIR */ + uartclk: 0, /* filled in dynamically */ + fifosize: 16, + unused: { AMAZONASC_TIR, AMAZONASC_EIR}, /* xmit/error/xmit-buffer-empty IRQ */ + type: PORT_AMAZONASC, + ops: &amazonasc_pops, + flags: ASYNC_BOOT_AUTOCONF, + }, +}; + +static void amazonasc_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;) + { + /* wait until the FIFO is not full */ + do + { + fifocnt = (amazon_readl(AMAZON_ASC_FSTAT) & ASCFSTAT_TXFFLMASK) + >> ASCFSTAT_TXFFLOFF; + } while (fifocnt == AMAZONASC_TXFIFO_FULL); + if (s[i] == '\0') + { + break; + } + if (s[i] == '\n') + { + amazon_writel('\r', AMAZON_ASC_TBUF); + do + { + fifocnt = (amazon_readl(AMAZON_ASC_FSTAT) & + ASCFSTAT_TXFFLMASK) >> ASCFSTAT_TXFFLOFF; + } while (fifocnt == AMAZONASC_TXFIFO_FULL); + } + amazon_writel(s[i], AMAZON_ASC_TBUF); + i++; + } + + local_irq_restore(flags); +} + +static void __init +amazonasc_console_get_options(struct uart_port *port, int *baud, int *parity, int *bits) +{ + u_int lcr_h; + + lcr_h = amazon_readl(AMAZON_ASC_CON); + /* do this only if the ASC is turned on */ + if (lcr_h & ASCCON_R) { + u_int quot, div, fdiv, frac; + + *parity = 'n'; + if ((lcr_h & ASCCON_MODEMASK) == ASCCON_M_7ASYNCPAR || + (lcr_h & ASCCON_MODEMASK) == ASCCON_M_8ASYNCPAR) { + if (lcr_h & ASCCON_ODD) + *parity = 'o'; + else + *parity = 'e'; + } + + if ((lcr_h & ASCCON_MODEMASK) == ASCCON_M_7ASYNCPAR) + *bits = 7; + else + *bits = 8; + + quot = amazon_readl(AMAZON_ASC_BTR) + 1; + + /* this gets hairy if the fractional divider is used */ + if (lcr_h & ASCCON_FDE) + { + div = 1; + fdiv = amazon_readl(AMAZON_ASC_FDV); + if (fdiv == 0) + fdiv = 512; + frac = 512; + } + else + { + div = lcr_h & ASCCON_BRS ? 3 : 2; + fdiv = frac = 1; + } + /* + * This doesn't work exactly because we use integer + * math to calculate baud which results in rounding + * errors when we try to go from quot -> baud !! + * Try to make this work for both the fractional divider + * and the simple divider. Also try to avoid rounding + * errors using integer math. + */ + + *baud = frac * (port->uartclk / (div * 512 * 16 * quot)); + if (*baud > 1100 && *baud < 2400) + *baud = 1200; + if (*baud > 2300 && *baud < 4800) + *baud = 2400; + if (*baud > 4700 && *baud < 9600) + *baud = 4800; + if (*baud > 9500 && *baud < 19200) + *baud = 9600; + if (*baud > 19000 && *baud < 38400) + *baud = 19200; + if (*baud > 38400 && *baud < 57600) + *baud = 38400; + if (*baud > 57600 && *baud < 115200) + *baud = 57600; + if (*baud > 115200 && *baud < 230400) + *baud = 115200; + } +} + +static int __init amazonasc_console_setup(struct console *co, char *options) +{ + struct uart_port *port; + int baud = 115200; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + + /* this assumes: CON.BRS = CON.FDE = 0 */ + if (uartclk == 0) + uartclk = amazon_get_fpi_hz(); + co->index = 0; + port = &amazonasc_ports[0]; + amazonasc_ports[0].uartclk = uartclk; + amazonasc_ports[0].type = PORT_AMAZONASC; + + if (options){ + uart_parse_options(options, &baud, &parity, &bits, &flow); + } + + return uart_set_options(port, co, baud, parity, bits, flow); +} + +static struct uart_driver amazonasc_reg; +static struct console amazonasc_console = { + name: "ttyS", + write: amazonasc_console_write, + device: uart_console_device, + setup: amazonasc_console_setup, + flags: CON_PRINTBUFFER, + index: -1, + data: &amazonasc_reg, +}; + +static struct uart_driver amazonasc_reg = { + .owner = THIS_MODULE, + .driver_name = "serial", + .dev_name = "ttyS", + .major = TTY_MAJOR, + .minor = 64, + .nr = UART_NR, + .cons = &amazonasc_console, +}; + +static int amazon_asc_probe(struct platform_device *dev) +{ + unsigned char res; + uart_register_driver(&amazonasc_reg); + res = uart_add_one_port(&amazonasc_reg, &amazonasc_ports[0]); + return res; +} + +static int amazon_asc_remove(struct platform_device *dev) +{ + uart_unregister_driver(&amazonasc_reg); + return 0; +} + +static struct platform_driver amazon_asc_driver = { + .probe = amazon_asc_probe, + .remove = amazon_asc_remove, + .driver = { + .name = "amazon_asc", + .owner = THIS_MODULE, + }, +}; + +static int __init amazon_asc_init(void) +{ + int ret = platform_driver_register(&amazon_asc_driver); + if (ret) + printk(KERN_WARNING "amazon_asc: error registering platfom driver!\n"); + return ret; +} + +static void __exit amazon_asc_cleanup(void) +{ + platform_driver_unregister(&amazon_asc_driver); +} + +module_init(amazon_asc_init); +module_exit(amazon_asc_cleanup); + +MODULE_AUTHOR("Gary Jennejohn, Felix Fietkau, John Crispin"); +MODULE_DESCRIPTION("MIPS AMAZONASC serial port driver"); +MODULE_LICENSE("GPL"); + |