[PATCH 6/6] media: hi556: Support device probe in non-zero ACPI D state

From: Bingbu Cao
Date: Tue Nov 09 2021 - 03:52:41 EST


Tell ACPI device PM code that the driver supports the device being in
non-zero ACPI D state when the driver's probe function is entered.

Also do identification on the first access of the device, whether in probe
or when starting streaming.

Signed-off-by: Bingbu Cao <bingbu.cao@xxxxxxxxx>
Signed-off-by: Kao, Arec <arec.kao@xxxxxxxxx>
---
drivers/media/i2c/hi556.c | 67 +++++++++++++++++++++++++++++------------------
1 file changed, 42 insertions(+), 25 deletions(-)

diff --git a/drivers/media/i2c/hi556.c b/drivers/media/i2c/hi556.c
index 8db1cbedc1fd..c8011467d1a4 100644
--- a/drivers/media/i2c/hi556.c
+++ b/drivers/media/i2c/hi556.c
@@ -495,6 +495,9 @@ struct hi556 {

/* Streaming on/off */
bool streaming;
+
+ /* True if the device has been identified */
+ bool identified;
};

static u64 to_pixel_rate(u32 f_index)
@@ -757,12 +760,38 @@ static void hi556_assign_pad_format(const struct hi556_mode *mode,
fmt->field = V4L2_FIELD_NONE;
}

+static int hi556_identify_module(struct hi556 *hi556)
+{
+ struct i2c_client *client = v4l2_get_subdevdata(&hi556->sd);
+ int ret;
+ u32 val;
+
+ ret = hi556_read_reg(hi556, HI556_REG_CHIP_ID,
+ HI556_REG_VALUE_16BIT, &val);
+ if (ret)
+ return ret;
+
+ if (val != HI556_CHIP_ID) {
+ dev_err(&client->dev, "chip id mismatch: %x!=%x",
+ HI556_CHIP_ID, val);
+ return -ENXIO;
+ }
+
+ hi556->identified = true;
+
+ return 0;
+}
+
static int hi556_start_streaming(struct hi556 *hi556)
{
struct i2c_client *client = v4l2_get_subdevdata(&hi556->sd);
const struct hi556_reg_list *reg_list;
int link_freq_index, ret;

+ ret = hi556_identify_module(hi556);
+ if (ret)
+ return ret;
+
link_freq_index = hi556->cur_mode->link_freq_index;
reg_list = &link_freq_configs[link_freq_index].reg_list;
ret = hi556_write_reg_list(hi556, reg_list);
@@ -1001,26 +1030,6 @@ static const struct v4l2_subdev_internal_ops hi556_internal_ops = {
.open = hi556_open,
};

-static int hi556_identify_module(struct hi556 *hi556)
-{
- struct i2c_client *client = v4l2_get_subdevdata(&hi556->sd);
- int ret;
- u32 val;
-
- ret = hi556_read_reg(hi556, HI556_REG_CHIP_ID,
- HI556_REG_VALUE_16BIT, &val);
- if (ret)
- return ret;
-
- if (val != HI556_CHIP_ID) {
- dev_err(&client->dev, "chip id mismatch: %x!=%x",
- HI556_CHIP_ID, val);
- return -ENXIO;
- }
-
- return 0;
-}
-
static int hi556_check_hwcfg(struct device *dev)
{
struct fwnode_handle *ep;
@@ -1106,6 +1115,7 @@ static int hi556_remove(struct i2c_client *client)
static int hi556_probe(struct i2c_client *client)
{
struct hi556 *hi556;
+ bool full_power;
int ret;

ret = hi556_check_hwcfg(&client->dev);
@@ -1120,10 +1130,14 @@ static int hi556_probe(struct i2c_client *client)
return -ENOMEM;

v4l2_i2c_subdev_init(&hi556->sd, client, &hi556_subdev_ops);
- ret = hi556_identify_module(hi556);
- if (ret) {
- dev_err(&client->dev, "failed to find sensor: %d", ret);
- return ret;
+
+ full_power = acpi_dev_state_d0(&client->dev);
+ if (full_power) {
+ ret = hi556_identify_module(hi556);
+ if (ret) {
+ dev_err(&client->dev, "failed to find sensor: %d", ret);
+ return ret;
+ }
}

mutex_init(&hi556->mutex);
@@ -1152,7 +1166,9 @@ static int hi556_probe(struct i2c_client *client)
goto probe_error_media_entity_cleanup;
}

- pm_runtime_set_active(&client->dev);
+ /* Set the device's state to active if it's in D0 state. */
+ if (full_power)
+ pm_runtime_set_active(&client->dev);
pm_runtime_enable(&client->dev);
pm_runtime_idle(&client->dev);

@@ -1189,6 +1205,7 @@ static struct i2c_driver hi556_i2c_driver = {
},
.probe_new = hi556_probe,
.remove = hi556_remove,
+ .flags = I2C_DRV_ACPI_WAIVE_D0_PROBE,
};

module_i2c_driver(hi556_i2c_driver);
--
2.7.4