diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/xtensa/platforms/iss/console.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 4.19.249.upstream/4.19.249upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/xtensa/platforms/iss/console.c')
-rw-r--r-- | arch/xtensa/platforms/iss/console.c | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/arch/xtensa/platforms/iss/console.c b/arch/xtensa/platforms/iss/console.c new file mode 100644 index 000000000..e7faea3d7 --- /dev/null +++ b/arch/xtensa/platforms/iss/console.c @@ -0,0 +1,268 @@ +/* + * arch/xtensa/platforms/iss/console.c + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2001-2005 Tensilica Inc. + * Authors Christian Zankel, Joe Taylor + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/console.h> +#include <linux/init.h> +#include <linux/mm.h> +#include <linux/major.h> +#include <linux/param.h> +#include <linux/seq_file.h> +#include <linux/serial.h> + +#include <linux/uaccess.h> +#include <asm/irq.h> + +#include <platform/simcall.h> + +#include <linux/tty.h> +#include <linux/tty_flip.h> + +#define SERIAL_MAX_NUM_LINES 1 +#define SERIAL_TIMER_VALUE (HZ / 10) + +static struct tty_driver *serial_driver; +static struct tty_port serial_port; +static struct timer_list serial_timer; + +static DEFINE_SPINLOCK(timer_lock); + +static char *serial_version = "0.1"; +static char *serial_name = "ISS serial driver"; + +/* + * 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 void rs_poll(struct timer_list *); + +static int rs_open(struct tty_struct *tty, struct file * filp) +{ + tty->port = &serial_port; + spin_lock_bh(&timer_lock); + if (tty->count == 1) { + timer_setup(&serial_timer, rs_poll, 0); + mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE); + } + spin_unlock_bh(&timer_lock); + + return 0; +} + + +/* + * ------------------------------------------------------------ + * iss_serial_close() + * + * This routine is called when the serial port gets closed. First, we + * wait for the last remaining data to be sent. Then, we unlink its + * async structure from the interrupt chain if necessary, and we free + * that IRQ if nothing is left in the chain. + * ------------------------------------------------------------ + */ +static void rs_close(struct tty_struct *tty, struct file * filp) +{ + spin_lock_bh(&timer_lock); + if (tty->count == 1) + del_timer_sync(&serial_timer); + spin_unlock_bh(&timer_lock); +} + + +static int rs_write(struct tty_struct * tty, + const unsigned char *buf, int count) +{ + /* see drivers/char/serialX.c to reference original version */ + + simc_write(1, buf, count); + return count; +} + +static void rs_poll(struct timer_list *unused) +{ + struct tty_port *port = &serial_port; + int i = 0; + int rd = 1; + unsigned char c; + + spin_lock(&timer_lock); + + while (simc_poll(0)) { + rd = simc_read(0, &c, 1); + if (rd <= 0) + break; + tty_insert_flip_char(port, c, TTY_NORMAL); + i++; + } + + if (i) + tty_flip_buffer_push(port); + if (rd) + mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE); + spin_unlock(&timer_lock); +} + + +static int rs_put_char(struct tty_struct *tty, unsigned char ch) +{ + return rs_write(tty, &ch, 1); +} + +static void rs_flush_chars(struct tty_struct *tty) +{ +} + +static int rs_write_room(struct tty_struct *tty) +{ + /* Let's say iss can always accept 2K characters.. */ + return 2 * 1024; +} + +static int rs_chars_in_buffer(struct tty_struct *tty) +{ + /* the iss doesn't buffer characters */ + return 0; +} + +static void rs_hangup(struct tty_struct *tty) +{ + /* Stub, once again.. */ +} + +static void rs_wait_until_sent(struct tty_struct *tty, int timeout) +{ + /* Stub, once again.. */ +} + +static int rs_proc_show(struct seq_file *m, void *v) +{ + seq_printf(m, "serinfo:1.0 driver:%s\n", serial_version); + return 0; +} + +static const struct tty_operations serial_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, + .hangup = rs_hangup, + .wait_until_sent = rs_wait_until_sent, + .proc_show = rs_proc_show, +}; + +int __init rs_init(void) +{ + int ret; + + serial_driver = alloc_tty_driver(SERIAL_MAX_NUM_LINES); + if (!serial_driver) + return -ENOMEM; + + tty_port_init(&serial_port); + + pr_info("%s %s\n", serial_name, serial_version); + + /* Initialize the tty_driver structure */ + + serial_driver->driver_name = "iss_serial"; + serial_driver->name = "ttyS"; + serial_driver->major = TTY_MAJOR; + serial_driver->minor_start = 64; + serial_driver->type = TTY_DRIVER_TYPE_SERIAL; + serial_driver->subtype = SERIAL_TYPE_NORMAL; + serial_driver->init_termios = tty_std_termios; + serial_driver->init_termios.c_cflag = + B9600 | CS8 | CREAD | HUPCL | CLOCAL; + serial_driver->flags = TTY_DRIVER_REAL_RAW; + + tty_set_operations(serial_driver, &serial_ops); + tty_port_link_device(&serial_port, serial_driver, 0); + + ret = tty_register_driver(serial_driver); + if (ret) { + pr_err("Couldn't register serial driver\n"); + tty_driver_kref_put(serial_driver); + tty_port_destroy(&serial_port); + + return ret; + } + + return 0; +} + + +static __exit void rs_exit(void) +{ + int error; + + if ((error = tty_unregister_driver(serial_driver))) + pr_err("ISS_SERIAL: failed to unregister serial driver (%d)\n", + error); + put_tty_driver(serial_driver); + tty_port_destroy(&serial_port); +} + + +/* We use `late_initcall' instead of just `__initcall' as a workaround for + * the fact that (1) simcons_tty_init can't be called before tty_init, + * (2) tty_init is called via `module_init', (3) if statically linked, + * module_init == device_init, and (4) there's no ordering of init lists. + * We can do this easily because simcons is always statically linked, but + * other tty drivers that depend on tty_init and which must use + * `module_init' to declare their init routines are likely to be broken. + */ + +late_initcall(rs_init); + + +#ifdef CONFIG_SERIAL_CONSOLE + +static void iss_console_write(struct console *co, const char *s, unsigned count) +{ + int len = strlen(s); + + if (s != 0 && *s != 0) + simc_write(1, s, count < len ? count : len); +} + +static struct tty_driver* iss_console_device(struct console *c, int *index) +{ + *index = c->index; + return serial_driver; +} + + +static struct console sercons = { + .name = "ttyS", + .write = iss_console_write, + .device = iss_console_device, + .flags = CON_PRINTBUFFER, + .index = -1 +}; + +static int __init iss_console_init(void) +{ + register_console(&sercons); + return 0; +} + +console_initcall(iss_console_init); + +#endif /* CONFIG_SERIAL_CONSOLE */ + |