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Subject[PATCH v2 1/6] media: ov8856: support device probe in non-zero ACPI D state
Date
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@intel.com>
---
drivers/media/i2c/ov8856.c | 162 +++++++++++++++++++++++++--------------------
1 file changed, 89 insertions(+), 73 deletions(-)

diff --git a/drivers/media/i2c/ov8856.c b/drivers/media/i2c/ov8856.c
index c6c6050cda1a..8785764b7a74 100644
--- a/drivers/media/i2c/ov8856.c
+++ b/drivers/media/i2c/ov8856.c
@@ -1445,6 +1445,9 @@ struct ov8856 {

const struct ov8856_lane_cfg *priv_lane;
u8 modes_size;
+
+ /* True if the device has been identified */
+ bool identified;
};

struct ov8856_lane_cfg {
@@ -1685,6 +1688,71 @@ static int ov8856_write_reg_list(struct ov8856 *ov8856,
return 0;
}

+static int ov8856_identify_module(struct ov8856 *ov8856)
+{
+ struct i2c_client *client = v4l2_get_subdevdata(&ov8856->sd);
+ int ret;
+ u32 val;
+
+ if (ov8856->identified)
+ return 0;
+
+ ret = ov8856_read_reg(ov8856, OV8856_REG_CHIP_ID,
+ OV8856_REG_VALUE_24BIT, &val);
+ if (ret)
+ return ret;
+
+ if (val != OV8856_CHIP_ID) {
+ dev_err(&client->dev, "chip id mismatch: %x!=%x",
+ OV8856_CHIP_ID, val);
+ return -ENXIO;
+ }
+
+ ret = ov8856_write_reg(ov8856, OV8856_REG_MODE_SELECT,
+ OV8856_REG_VALUE_08BIT, OV8856_MODE_STREAMING);
+ if (ret)
+ return ret;
+
+ ret = ov8856_write_reg(ov8856, OV8856_OTP_MODE_CTRL,
+ OV8856_REG_VALUE_08BIT, OV8856_OTP_MODE_AUTO);
+ if (ret) {
+ dev_err(&client->dev, "failed to set otp mode");
+ return ret;
+ }
+
+ ret = ov8856_write_reg(ov8856, OV8856_OTP_LOAD_CTRL,
+ OV8856_REG_VALUE_08BIT,
+ OV8856_OTP_LOAD_CTRL_ENABLE);
+ if (ret) {
+ dev_err(&client->dev, "failed to enable load control");
+ return ret;
+ }
+
+ ret = ov8856_read_reg(ov8856, OV8856_MODULE_REVISION,
+ OV8856_REG_VALUE_08BIT, &val);
+ if (ret) {
+ dev_err(&client->dev, "failed to read module revision");
+ return ret;
+ }
+
+ dev_info(&client->dev, "OV8856 revision %x (%s) at address 0x%02x\n",
+ val,
+ val == OV8856_2A_MODULE ? "2A" :
+ val == OV8856_1B_MODULE ? "1B" : "unknown revision",
+ client->addr);
+
+ ret = ov8856_write_reg(ov8856, OV8856_REG_MODE_SELECT,
+ OV8856_REG_VALUE_08BIT, OV8856_MODE_STANDBY);
+ if (ret) {
+ dev_err(&client->dev, "failed to exit streaming mode");
+ return ret;
+ }
+
+ ov8856->identified = true;
+
+ return 0;
+}
+
static int ov8856_update_digital_gain(struct ov8856 *ov8856, u32 d_gain)
{
int ret;
@@ -1969,6 +2037,10 @@ static int ov8856_start_streaming(struct ov8856 *ov8856)
const struct ov8856_reg_list *reg_list;
int link_freq_index, ret;

+ ret = ov8856_identify_module(ov8856);
+ if (ret)
+ return ret;
+
link_freq_index = ov8856->cur_mode->link_freq_index;
reg_list = &ov8856->priv_lane->link_freq_configs[link_freq_index].reg_list;

@@ -2276,65 +2348,6 @@ static const struct v4l2_subdev_internal_ops ov8856_internal_ops = {
.open = ov8856_open,
};

-static int ov8856_identify_module(struct ov8856 *ov8856)
-{
- struct i2c_client *client = v4l2_get_subdevdata(&ov8856->sd);
- int ret;
- u32 val;
-
- ret = ov8856_read_reg(ov8856, OV8856_REG_CHIP_ID,
- OV8856_REG_VALUE_24BIT, &val);
- if (ret)
- return ret;
-
- if (val != OV8856_CHIP_ID) {
- dev_err(&client->dev, "chip id mismatch: %x!=%x",
- OV8856_CHIP_ID, val);
- return -ENXIO;
- }
-
- ret = ov8856_write_reg(ov8856, OV8856_REG_MODE_SELECT,
- OV8856_REG_VALUE_08BIT, OV8856_MODE_STREAMING);
- if (ret)
- return ret;
-
- ret = ov8856_write_reg(ov8856, OV8856_OTP_MODE_CTRL,
- OV8856_REG_VALUE_08BIT, OV8856_OTP_MODE_AUTO);
- if (ret) {
- dev_err(&client->dev, "failed to set otp mode");
- return ret;
- }
-
- ret = ov8856_write_reg(ov8856, OV8856_OTP_LOAD_CTRL,
- OV8856_REG_VALUE_08BIT,
- OV8856_OTP_LOAD_CTRL_ENABLE);
- if (ret) {
- dev_err(&client->dev, "failed to enable load control");
- return ret;
- }
-
- ret = ov8856_read_reg(ov8856, OV8856_MODULE_REVISION,
- OV8856_REG_VALUE_08BIT, &val);
- if (ret) {
- dev_err(&client->dev, "failed to read module revision");
- return ret;
- }
-
- dev_info(&client->dev, "OV8856 revision %x (%s) at address 0x%02x\n",
- val,
- val == OV8856_2A_MODULE ? "2A" :
- val == OV8856_1B_MODULE ? "1B" : "unknown revision",
- client->addr);
-
- ret = ov8856_write_reg(ov8856, OV8856_REG_MODE_SELECT,
- OV8856_REG_VALUE_08BIT, OV8856_MODE_STANDBY);
- if (ret) {
- dev_err(&client->dev, "failed to exit streaming mode");
- return ret;
- }
-
- return 0;
-}

static int ov8856_get_hwcfg(struct ov8856 *ov8856, struct device *dev)
{
@@ -2458,6 +2471,7 @@ static int ov8856_probe(struct i2c_client *client)
{
struct ov8856 *ov8856;
int ret;
+ bool full_power;

ov8856 = devm_kzalloc(&client->dev, sizeof(*ov8856), GFP_KERNEL);
if (!ov8856)
@@ -2472,16 +2486,19 @@ static int ov8856_probe(struct i2c_client *client)

v4l2_i2c_subdev_init(&ov8856->sd, client, &ov8856_subdev_ops);

- ret = __ov8856_power_on(ov8856);
- if (ret) {
- dev_err(&client->dev, "failed to power on\n");
- return ret;
- }
+ full_power = acpi_dev_state_d0(&client->dev);
+ if (full_power) {
+ ret = __ov8856_power_on(ov8856);
+ if (ret) {
+ dev_err(&client->dev, "failed to power on\n");
+ return ret;
+ }

- ret = ov8856_identify_module(ov8856);
- if (ret) {
- dev_err(&client->dev, "failed to find sensor: %d", ret);
- goto probe_power_off;
+ ret = ov8856_identify_module(ov8856);
+ if (ret) {
+ dev_err(&client->dev, "failed to find sensor: %d", ret);
+ goto probe_power_off;
+ }
}

mutex_init(&ov8856->mutex);
@@ -2511,11 +2528,9 @@ static int ov8856_probe(struct i2c_client *client)
goto probe_error_media_entity_cleanup;
}

- /*
- * Device is already turned on by i2c-core with ACPI domain PM.
- * Enable runtime PM and turn off the device.
- */
- 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);

@@ -2562,6 +2577,7 @@ static struct i2c_driver ov8856_i2c_driver = {
},
.probe_new = ov8856_probe,
.remove = ov8856_remove,
+ .flags = I2C_DRV_ACPI_WAIVE_D0_PROBE,
};

module_i2c_driver(ov8856_i2c_driver);
--
2.7.4
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