diff options
Diffstat (limited to 'kernel/arch/ia64/hp/sim/simserial.c')
| -rw-r--r-- | kernel/arch/ia64/hp/sim/simserial.c | 545 |
1 files changed, 545 insertions, 0 deletions
diff --git a/kernel/arch/ia64/hp/sim/simserial.c b/kernel/arch/ia64/hp/sim/simserial.c new file mode 100644 index 000000000..e70cadec7 --- /dev/null +++ b/kernel/arch/ia64/hp/sim/simserial.c @@ -0,0 +1,545 @@ +/* + * Simulated Serial Driver (fake serial) + * + * This driver is mostly used for bringup purposes and will go away. + * It has a strong dependency on the system console. All outputs + * are rerouted to the same facility as the one used by printk which, in our + * case means sys_sim.c console (goes via the simulator). + * + * Copyright (C) 1999-2000, 2002-2003 Hewlett-Packard Co + * Stephane Eranian <eranian@hpl.hp.com> + * David Mosberger-Tang <davidm@hpl.hp.com> + */ + +#include <linux/init.h> +#include <linux/errno.h> +#include <linux/sched.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <linux/major.h> +#include <linux/fcntl.h> +#include <linux/mm.h> +#include <linux/seq_file.h> +#include <linux/slab.h> +#include <linux/capability.h> +#include <linux/circ_buf.h> +#include <linux/console.h> +#include <linux/irq.h> +#include <linux/module.h> +#include <linux/serial.h> +#include <linux/sysrq.h> +#include <linux/uaccess.h> + +#include <asm/hpsim.h> + +#include "hpsim_ssc.h" + +#undef SIMSERIAL_DEBUG /* define this to get some debug information */ + +#define KEYBOARD_INTR 3 /* must match with simulator! */ + +#define NR_PORTS 1 /* only one port for now */ + +struct serial_state { + struct tty_port port; + struct circ_buf xmit; + int irq; + int x_char; +}; + +static struct serial_state rs_table[NR_PORTS]; + +struct tty_driver *hp_simserial_driver; + +static struct console *console; + +static void receive_chars(struct tty_port *port) +{ + unsigned char ch; + static unsigned char seen_esc = 0; + + while ( (ch = ia64_ssc(0, 0, 0, 0, SSC_GETCHAR)) ) { + if (ch == 27 && seen_esc == 0) { + seen_esc = 1; + continue; + } else if (seen_esc == 1 && ch == 'O') { + seen_esc = 2; + continue; + } else if (seen_esc == 2) { + if (ch == 'P') /* F1 */ + show_state(); +#ifdef CONFIG_MAGIC_SYSRQ + if (ch == 'S') { /* F4 */ + do { + ch = ia64_ssc(0, 0, 0, 0, SSC_GETCHAR); + } while (!ch); + handle_sysrq(ch); + } +#endif + seen_esc = 0; + continue; + } + seen_esc = 0; + + if (tty_insert_flip_char(port, ch, TTY_NORMAL) == 0) + break; + } + tty_flip_buffer_push(port); +} + +/* + * This is the serial driver's interrupt routine for a single port + */ +static irqreturn_t rs_interrupt_single(int irq, void *dev_id) +{ + struct serial_state *info = dev_id; + + receive_chars(&info->port); + + return IRQ_HANDLED; +} + +/* + * ------------------------------------------------------------------- + * Here ends the serial interrupt routines. + * ------------------------------------------------------------------- + */ + +static int rs_put_char(struct tty_struct *tty, unsigned char ch) +{ + struct serial_state *info = tty->driver_data; + unsigned long flags; + + if (!info->xmit.buf) + return 0; + + local_irq_save(flags); + if (CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE) == 0) { + local_irq_restore(flags); + return 0; + } + info->xmit.buf[info->xmit.head] = ch; + info->xmit.head = (info->xmit.head + 1) & (SERIAL_XMIT_SIZE-1); + local_irq_restore(flags); + return 1; +} + +static void transmit_chars(struct tty_struct *tty, struct serial_state *info, + int *intr_done) +{ + int count; + unsigned long flags; + + local_irq_save(flags); + + if (info->x_char) { + char c = info->x_char; + + console->write(console, &c, 1); + + info->x_char = 0; + + goto out; + } + + if (info->xmit.head == info->xmit.tail || tty->stopped) { +#ifdef SIMSERIAL_DEBUG + printk("transmit_chars: head=%d, tail=%d, stopped=%d\n", + info->xmit.head, info->xmit.tail, tty->stopped); +#endif + goto out; + } + /* + * We removed the loop and try to do it in to chunks. We need + * 2 operations maximum because it's a ring buffer. + * + * First from current to tail if possible. + * Then from the beginning of the buffer until necessary + */ + + count = min(CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE), + SERIAL_XMIT_SIZE - info->xmit.tail); + console->write(console, info->xmit.buf+info->xmit.tail, count); + + info->xmit.tail = (info->xmit.tail+count) & (SERIAL_XMIT_SIZE-1); + + /* + * We have more at the beginning of the buffer + */ + count = CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE); + if (count) { + console->write(console, info->xmit.buf, count); + info->xmit.tail += count; + } +out: + local_irq_restore(flags); +} + +static void rs_flush_chars(struct tty_struct *tty) +{ + struct serial_state *info = tty->driver_data; + + if (info->xmit.head == info->xmit.tail || tty->stopped || + !info->xmit.buf) + return; + + transmit_chars(tty, info, NULL); +} + +static int rs_write(struct tty_struct * tty, + const unsigned char *buf, int count) +{ + struct serial_state *info = tty->driver_data; + int c, ret = 0; + unsigned long flags; + + if (!info->xmit.buf) + return 0; + + local_irq_save(flags); + while (1) { + c = CIRC_SPACE_TO_END(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE); + if (count < c) + c = count; + if (c <= 0) { + break; + } + memcpy(info->xmit.buf + info->xmit.head, buf, c); + info->xmit.head = ((info->xmit.head + c) & + (SERIAL_XMIT_SIZE-1)); + buf += c; + count -= c; + ret += c; + } + local_irq_restore(flags); + /* + * Hey, we transmit directly from here in our case + */ + if (CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE) && + !tty->stopped) + transmit_chars(tty, info, NULL); + + return ret; +} + +static int rs_write_room(struct tty_struct *tty) +{ + struct serial_state *info = tty->driver_data; + + return CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE); +} + +static int rs_chars_in_buffer(struct tty_struct *tty) +{ + struct serial_state *info = tty->driver_data; + + return CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE); +} + +static void rs_flush_buffer(struct tty_struct *tty) +{ + struct serial_state *info = tty->driver_data; + unsigned long flags; + + local_irq_save(flags); + info->xmit.head = info->xmit.tail = 0; + local_irq_restore(flags); + + tty_wakeup(tty); +} + +/* + * This function is used to send a high-priority XON/XOFF character to + * the device + */ +static void rs_send_xchar(struct tty_struct *tty, char ch) +{ + struct serial_state *info = tty->driver_data; + + info->x_char = ch; + if (ch) { + /* + * I guess we could call console->write() directly but + * let's do that for now. + */ + transmit_chars(tty, info, NULL); + } +} + +/* + * ------------------------------------------------------------ + * rs_throttle() + * + * This routine is called by the upper-layer tty layer to signal that + * incoming characters should be throttled. + * ------------------------------------------------------------ + */ +static void rs_throttle(struct tty_struct * tty) +{ + if (I_IXOFF(tty)) + rs_send_xchar(tty, STOP_CHAR(tty)); + + printk(KERN_INFO "simrs_throttle called\n"); +} + +static void rs_unthrottle(struct tty_struct * tty) +{ + struct serial_state *info = tty->driver_data; + + if (I_IXOFF(tty)) { + if (info->x_char) + info->x_char = 0; + else + rs_send_xchar(tty, START_CHAR(tty)); + } + printk(KERN_INFO "simrs_unthrottle called\n"); +} + +static int rs_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg) +{ + if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) && + (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGSTRUCT) && + (cmd != TIOCMIWAIT)) { + if (tty->flags & (1 << TTY_IO_ERROR)) + return -EIO; + } + + switch (cmd) { + case TIOCGSERIAL: + case TIOCSSERIAL: + case TIOCSERGSTRUCT: + case TIOCMIWAIT: + return 0; + case TIOCSERCONFIG: + case TIOCSERGETLSR: /* Get line status register */ + return -EINVAL; + case TIOCSERGWILD: + case TIOCSERSWILD: + /* "setserial -W" is called in Debian boot */ + printk (KERN_INFO "TIOCSER?WILD ioctl obsolete, ignored.\n"); + return 0; + } + return -ENOIOCTLCMD; +} + +#define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK)) + +/* + * This routine will shutdown a serial port; interrupts are disabled, and + * DTR is dropped if the hangup on close termio flag is on. + */ +static void shutdown(struct tty_port *port) +{ + struct serial_state *info = container_of(port, struct serial_state, + port); + unsigned long flags; + + local_irq_save(flags); + if (info->irq) + free_irq(info->irq, info); + + if (info->xmit.buf) { + free_page((unsigned long) info->xmit.buf); + info->xmit.buf = NULL; + } + local_irq_restore(flags); +} + +static void rs_close(struct tty_struct *tty, struct file * filp) +{ + struct serial_state *info = tty->driver_data; + + tty_port_close(&info->port, tty, filp); +} + +static void rs_hangup(struct tty_struct *tty) +{ + struct serial_state *info = tty->driver_data; + + rs_flush_buffer(tty); + tty_port_hangup(&info->port); +} + +static int activate(struct tty_port *port, struct tty_struct *tty) +{ + struct serial_state *state = container_of(port, struct serial_state, + port); + unsigned long flags, page; + int retval = 0; + + page = get_zeroed_page(GFP_KERNEL); + if (!page) + return -ENOMEM; + + local_irq_save(flags); + + if (state->xmit.buf) + free_page(page); + else + state->xmit.buf = (unsigned char *) page; + + if (state->irq) { + retval = request_irq(state->irq, rs_interrupt_single, 0, + "simserial", state); + if (retval) + goto errout; + } + + state->xmit.head = state->xmit.tail = 0; + + /* + * Set up the tty->alt_speed kludge + */ + if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI) + tty->alt_speed = 57600; + if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI) + tty->alt_speed = 115200; + if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI) + tty->alt_speed = 230400; + if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP) + tty->alt_speed = 460800; + +errout: + local_irq_restore(flags); + return retval; +} + + +/* + * This routine is called whenever a serial port is opened. It + * enables interrupts for a serial port, linking in its async structure into + * the IRQ chain. It also performs the serial-specific + * initialization for the tty structure. + */ +static int rs_open(struct tty_struct *tty, struct file * filp) +{ + struct serial_state *info = rs_table + tty->index; + struct tty_port *port = &info->port; + + tty->driver_data = info; + port->low_latency = (port->flags & ASYNC_LOW_LATENCY) ? 1 : 0; + + /* + * figure out which console to use (should be one already) + */ + console = console_drivers; + while (console) { + if ((console->flags & CON_ENABLED) && console->write) break; + console = console->next; + } + + return tty_port_open(port, tty, filp); +} + +/* + * /proc fs routines.... + */ + +static int rs_proc_show(struct seq_file *m, void *v) +{ + int i; + + seq_printf(m, "simserinfo:1.0\n"); + for (i = 0; i < NR_PORTS; i++) + seq_printf(m, "%d: uart:16550 port:3F8 irq:%d\n", + i, rs_table[i].irq); + return 0; +} + +static int rs_proc_open(struct inode *inode, struct file *file) +{ + return single_open(file, rs_proc_show, NULL); +} + +static const struct file_operations rs_proc_fops = { + .owner = THIS_MODULE, + .open = rs_proc_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static const struct tty_operations hp_ops = { + .open = rs_open, + .close = rs_close, + .write = rs_write, + .put_char = rs_put_char, + .flush_chars = rs_flush_chars, + .write_room = rs_write_room, + .chars_in_buffer = rs_chars_in_buffer, + .flush_buffer = rs_flush_buffer, + .ioctl = rs_ioctl, + .throttle = rs_throttle, + .unthrottle = rs_unthrottle, + .send_xchar = rs_send_xchar, + .hangup = rs_hangup, + .proc_fops = &rs_proc_fops, +}; + +static const struct tty_port_operations hp_port_ops = { + .activate = activate, + .shutdown = shutdown, +}; + +static int __init simrs_init(void) +{ + struct serial_state *state; + int retval; + + if (!ia64_platform_is("hpsim")) + return -ENODEV; + + hp_simserial_driver = alloc_tty_driver(NR_PORTS); + if (!hp_simserial_driver) + return -ENOMEM; + + printk(KERN_INFO "SimSerial driver with no serial options enabled\n"); + + /* Initialize the tty_driver structure */ + + hp_simserial_driver->driver_name = "simserial"; + hp_simserial_driver->name = "ttyS"; + hp_simserial_driver->major = TTY_MAJOR; + hp_simserial_driver->minor_start = 64; + hp_simserial_driver->type = TTY_DRIVER_TYPE_SERIAL; + hp_simserial_driver->subtype = SERIAL_TYPE_NORMAL; + hp_simserial_driver->init_termios = tty_std_termios; + hp_simserial_driver->init_termios.c_cflag = + B9600 | CS8 | CREAD | HUPCL | CLOCAL; + hp_simserial_driver->flags = TTY_DRIVER_REAL_RAW; + tty_set_operations(hp_simserial_driver, &hp_ops); + + state = rs_table; + tty_port_init(&state->port); + state->port.ops = &hp_port_ops; + state->port.close_delay = 0; /* XXX really 0? */ + + retval = hpsim_get_irq(KEYBOARD_INTR); + if (retval < 0) { + printk(KERN_ERR "%s: out of interrupt vectors!\n", + __func__); + goto err_free_tty; + } + + state->irq = retval; + + /* the port is imaginary */ + printk(KERN_INFO "ttyS0 at 0x03f8 (irq = %d) is a 16550\n", state->irq); + + tty_port_link_device(&state->port, hp_simserial_driver, 0); + retval = tty_register_driver(hp_simserial_driver); + if (retval) { + printk(KERN_ERR "Couldn't register simserial driver\n"); + goto err_free_tty; + } + + return 0; +err_free_tty: + put_tty_driver(hp_simserial_driver); + tty_port_destroy(&state->port); + return retval; +} + +#ifndef MODULE +__initcall(simrs_init); +#endif |