arch/xtensa/platforms/iss/console.c

Source file repositories/reference/linux-study-clean/arch/xtensa/platforms/iss/console.c

File Facts

System
Linux kernel
Corpus path
arch/xtensa/platforms/iss/console.c
Extension
.c
Size
4377 bytes
Lines
198
Domain
Architecture Layer
Bucket
arch/xtensa
Inferred role
Architecture Layer: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

#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 void rs_poll(struct timer_list *);

static struct tty_driver *serial_driver;
static struct tty_port serial_port;
static DEFINE_TIMER(serial_timer, rs_poll);

static int rs_open(struct tty_struct *tty, struct file * filp)
{
	if (tty->count == 1)
		mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);

	return 0;
}

static void rs_close(struct tty_struct *tty, struct file * filp)
{
	if (tty->count == 1)
		timer_delete_sync(&serial_timer);
}


static ssize_t rs_write(struct tty_struct * tty, const u8 *buf, size_t 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;
	u8 c;

	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);
}

static unsigned int rs_write_room(struct tty_struct *tty)
{
	/* Let's say iss can always accept 2K characters.. */
	return 2 * 1024;
}

static int rs_proc_show(struct seq_file *m, void *v)
{
	seq_printf(m, "serinfo:1.0 driver:0.1\n");
	return 0;
}

static const struct tty_operations serial_ops = {
	.open = rs_open,
	.close = rs_close,
	.write = rs_write,
	.write_room = rs_write_room,
	.proc_show = rs_proc_show,

Annotation

Implementation Notes