[PATCH v1 07/11] ti948: Add sysfs node for alive attribute

[Michael Drake]

This may be used by userspace to determine the state
of the device.

Signed-off-by: Michael Drake <michael.dr...@codethink.co.uk>
Cc: Patrick Glaser <pgla...@tesla.com>
Cc: Nate Case <nc...@tesla.com>
---
 drivers/gpu/drm/bridge/ti948.c | 28 ++++++++++++++++++++++++++--
 1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ti948.c b/drivers/gpu/drm/bridge/ti948.c
index b5c766711c4b..b624eaeabb43 100644
--- a/drivers/gpu/drm/bridge/ti948.c
+++ b/drivers/gpu/drm/bridge/ti948.c
@@ -412,6 +412,16 @@ static void ti948_alive_check(struct work_struct *work)
        schedule_delayed_work(&ti948->alive_check, TI948_ALIVE_CHECK_DELAY);
 }
 
+static ssize_t alive_show(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       struct ti948_ctx *ti948 = ti948_ctx_from_dev(dev);
+
+       return scnprintf(buf, PAGE_SIZE, "%u\n", (unsigned int)ti948->alive);
+}
+
+static DEVICE_ATTR_RO(alive);
+
 static int ti948_pm_resume(struct device *dev)
 {
        struct ti948_ctx *ti948 = ti948_ctx_from_dev(dev);
@@ -614,17 +624,31 @@ static int ti948_probe(struct i2c_client *client,
 
        i2c_set_clientdata(client, ti948);
 
+       ret = device_create_file(&client->dev, &dev_attr_alive);
+       if (ret) {
+               dev_err(&client->dev, "Could not create alive attr\n");
+               return ret;
+       }
+
        ret = ti948_pm_resume(&client->dev);
-       if (ret != 0)
-               return -EPROBE_DEFER;
+       if (ret != 0) {
+               ret = -EPROBE_DEFER;
+               goto error;
+       }
 
        dev_info(&ti948->i2c->dev, "End probe (addr: %x)\n", ti948->i2c->addr);
 
        return 0;
+
+error:
+       device_remove_file(&client->dev, &dev_attr_alive);
+       return ret;
 }
 
 static int ti948_remove(struct i2c_client *client)
 {
+       device_remove_file(&client->dev, &dev_attr_alive);
+
        return ti948_pm_suspend(&client->dev);
 }
 
-- 
2.20.1