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