greybus: more uart work (a18e1517) · Commits · e / devices / android_kernel_fairphone_FP4

drivers/staging/greybus/uart-gb.c

+103 −3

Original line number	Diff line number	Diff line
		@@ -17,6 +17,7 @@
		#include "greybus.h"

		#define GB_TTY_MAJOR 180 /* FIXME use a real number!!! */
		#define GB_NUM_MINORS 255 /* 255 is enough for anyone... */

		struct gb_tty {
		struct tty_port port;
		@@ -24,6 +25,10 @@ struct gb_tty {
		int cport;
		unsigned int minor;
		unsigned char clocal;
		unsigned int throttled:1;
		unsigned int throttle_req:1;
		spinlock_t read_lock;
		spinlock_t write_lock;
		// FIXME locking!!!
		};

		@@ -115,6 +120,57 @@ static void gb_tty_hangup(struct tty_struct *tty)
		tty_port_hangup(&gb_tty->port);
		}

		static int gb_tty_write(struct tty_struct tty, const unsigned char buf,
		int count)
		{
		struct gb_tty *gb_tty = tty->driver_data;

		// FIXME - actually implement...

		return 0;
		}

		static int gb_tty_write_room(struct tty_struct *tty)
		{
		struct gb_tty *gb_tty = tty->driver_data;

		// FIXME - how much do we want to say we have room for?
		return 0;
		}

		static int gb_tty_chars_in_buffer(struct tty_struct *tty)
		{
		struct gb_tty *gb_tty = tty->driver_data;

		// FIXME - how many left to send?
		return 0;
		}

		static void gb_tty_throttle(struct tty_struct *tty)
		{
		struct gb_tty *gb_tty = tty->driver_data;

		spin_lock_irq(&gb_tty->read_lock);
		gb_tty->throttle_req = 1;
		spin_unlock_irq(&gb_tty->read_lock);
		}

		static void gb_tty_unthrottle(struct tty_struct *tty)
		{
		struct gb_tty *gb_tty = tty->driver_data;
		unsigned int was_throttled;

		spin_lock_irq(&gb_tty->read_lock);
		was_throttled = gb_tty->throttled;
		gb_tty->throttle_req = 0;
		gb_tty->throttled = 0;
		spin_unlock_irq(&gb_tty->read_lock);

		if (was_throttled) {
		// FIXME - send more data
		}
		}


		static const struct tty_operations gb_ops = {
		.install = gb_tty_install,
		@@ -137,14 +193,58 @@ static const struct tty_operations gb_ops = {

		static int tty_gb_probe(struct greybus_device gdev, const struct greybus_device_id id)
		{
		struct gb_tty *gb_tty;
		struct device *tty_dev;
		int retval;
		int minor;

		gb_tty = devm_kzalloc(&gdev->dev, sizeof(*gb_tty), GFP_KERNEL);
		if (!gb_tty)
		return -ENOMEM;

		minor = alloc_minor(gb_tty);
		if (minor == GB_NUM_MINORS) {
		dev_err(&gdev->dev, "no more free minor numbers\n");
		return -ENODEV;
		}

		gb_tty->minor = minor;
		gb_tty->gdev = gdev;
		spin_lock_init(&gb_tty->write_lock);
		spin_lock_init(&gb_tty->read_lock);

		/* FIXME - allocate gb buffers */

		greybus_set_drvdata(gdev, gb_tty);

		tty_dev = tty_port_register_device(&gb_tty->port, gb_tty_driver, minor,
		&gdev->dev);
		if (IS_ERR(tty_dev)) {
		retval = PTR_ERR(tty_dev);
		goto error;
		}

		//greybus_set_drvdata(gdev, i2c_gb_data);
		return 0;
		error:
		release_minor(gb_tty);
		return retval;
		}

		static void tty_gb_disconnect(struct greybus_device *gdev)
		{
		struct gb_tty *gb_tty = greybus_get_drvdata(gdev);
		struct tty_struct *tty;

		tty = tty_port_tty_get(&gb_tty->port);
		if (tty) {
		tty_vhangup(tty);
		tty_kref_put(tty);
		}
		/* FIXME - stop all traffic */

		tty_unregister_device(gb_tty_driver, gb_tty->minor);

		tty_port_put(&gb_tty->port);
		}

		static struct greybus_driver tty_gb_driver = {
		@@ -158,7 +258,7 @@ static int __init gb_tty_init(void)
		{
		int retval;

		gb_tty_driver = alloc_tty_driver(255);
		gb_tty_driver = alloc_tty_driver(GB_NUM_MINORS);
		if (!gb_tty_driver)
		return -ENOMEM;