[PATCH v1 06/11] ti948: Reconfigure in the alive check when device returns

From: Michael Drake
Date: Tue Jun 11 2019 - 10:10:06 EST


If the alive check detects a transition to the alive state,
the device configuration is rewritten.

Signed-off-by: Michael Drake <michael.drake@xxxxxxxxxxxxxxx>
Cc: Patrick Glaser <pglaser@xxxxxxxxx>
Cc: Nate Case <ncase@xxxxxxxxx>
---
drivers/gpu/drm/bridge/ti948.c | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/ti948.c b/drivers/gpu/drm/bridge/ti948.c
index 86daa3701b91..b5c766711c4b 100644
--- a/drivers/gpu/drm/bridge/ti948.c
+++ b/drivers/gpu/drm/bridge/ti948.c
@@ -132,6 +132,8 @@ struct ti948_reg_val {
* @reg_names: Array of regulator names, or NULL.
* @regs: Array of regulators, or NULL.
* @reg_count: Number of entries in reg_names and regs arrays.
+ * @alive_check: Context for the alive checking work item.
+ * @alive: Whether the device is alive or not (alive_check).
*/
struct ti948_ctx {
struct i2c_client *i2c;
@@ -141,6 +143,8 @@ struct ti948_ctx {
const char **reg_names;
struct regulator **regs;
size_t reg_count;
+ struct delayed_work alive_check;
+ bool alive;
};

static bool ti948_readable_reg(struct device *dev, unsigned int reg)
@@ -346,6 +350,8 @@ static int ti948_power_on(struct ti948_ctx *ti948)
if (ret != 0)
return ret;

+ ti948->alive = true;
+
msleep(500);

return 0;
@@ -356,6 +362,8 @@ static int ti948_power_off(struct ti948_ctx *ti948)
int i;
int ret;

+ ti948->alive = false;
+
for (i = ti948->reg_count; i > 0; i--) {
dev_info(&ti948->i2c->dev, "Disabling %s regulator\n",
ti948->reg_names[i - 1]);
@@ -388,8 +396,17 @@ static void ti948_alive_check(struct work_struct *work)
{
struct delayed_work *dwork = to_delayed_work(work);
struct ti948_ctx *ti948 = delayed_work_to_ti948_ctx(dwork);
+ int ret = ti948_device_check(ti948);

- dev_info(&ti948->i2c->dev, "%s Alive check!\n", __func__);
+ if (ti948->alive == false && ret == 0) {
+ dev_info(&ti948->i2c->dev, "Device has come back to life!\n");
+ ti948_write_config_seq(ti948);
+ ti948->alive = true;
+
+ } else if (ti948->alive == true && ret != 0) {
+ dev_info(&ti948->i2c->dev, "Device has stopped responding\n");
+ ti948->alive = false;
+ }

/* Reschedule ourself for the next check. */
schedule_delayed_work(&ti948->alive_check, TI948_ALIVE_CHECK_DELAY);
--
2.20.1