greybus: more uart work
diff --git a/drivers/staging/greybus/uart-gb.c b/drivers/staging/greybus/uart-gb.c
index 3eaada9..792536c 100644
--- a/drivers/staging/greybus/uart-gb.c
+++ b/drivers/staging/greybus/uart-gb.c
@@ -16,7 +16,8 @@
#include <linux/idr.h>
#include "greybus.h"
-#define GB_TTY_MAJOR 180 /* FIXME use a real number!!! */
+#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 @@
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 @@
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 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;
- //greybus_set_drvdata(gdev, i2c_gb_data);
+ 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;
+ }
+
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 @@
{
int retval;
- gb_tty_driver = alloc_tty_driver(255);
+ gb_tty_driver = alloc_tty_driver(GB_NUM_MINORS);
if (!gb_tty_driver)
return -ENOMEM;