mango/kernel/tty/device.c

#include <socks/tty.h>
#include <socks/device.h>
#include <socks/console.h>
#include <socks/libc/stdio.h>

static struct char_device_ops tty_ops = {
	.read = tty_read,
	.write = tty_write,
};

static struct device *tty_printk_output = NULL;

static void tty_console_write(struct console *con, const char *s, unsigned int len)
{
	size_t nr_written;
	tty_write(tty_printk_output, s, len, &nr_written, 0);
}

static struct console tty_console = {
	.c_name = "tty",
	.c_write = tty_console_write,
};

struct device *tty_device_create(void)
{
	struct char_device *cdev = char_device_create();
	if (!cdev) {
		return NULL;
	}

	struct tty_device *tty_dev = kmalloc(sizeof *tty_dev, VM_NORMAL);
	if (!tty_dev) {
		/* TODO destroy cdev */
		return NULL;
	}

	cdev->c_ops = &tty_ops;
	cdev->c_tty = tty_dev;

	return char_device_base(cdev);
}

static kern_status_t generate_name(struct tty_driver *owner, struct device *dev, char out[DEV_NAME_MAX])
{
	/* minor numbers start at 1. subtract 1 to start at 0 instead */
	snprintf(out, DEV_NAME_MAX, "%s%u", owner->tty_name, dev->dev_minor - 1);
	return KERN_OK;
}

kern_status_t tty_device_register(struct device *dev, struct tty_driver *owner, struct device *parent)
{
	kern_status_t status = device_register(dev, tty_driver_base(owner), parent);
	if (status != KERN_OK) {
		return status;
	}

	char link_name[DEV_NAME_MAX];
	generate_name(owner, dev, link_name);
	char link_path[OBJECT_PATH_MAX];
	snprintf(link_path, sizeof link_path, "/dev/tty/%s", link_name);

	return object_namespace_create_link(global_namespace(), link_path, &dev->dev_base);
}

void tty_set_printk_output(struct device *tty)
{
	bool console_init = false;
	if (tty_printk_output) {
		console_init = true;
	}

	tty_printk_output = tty;

	if (!console_init) {
		console_register(&tty_console);
	}
}