[PATCH v2 0/6] Support device probe in non-zero ACPI D state

[PATCH v2 0/6] Support device probe in non-zero ACPI D state

[Bingbu Cao]

In many use cases where the chip is part of a camera module, and the camera
module is wired together with a privacy LED, powering on the device during
probe will cause the LED blink, it is undesireable as the privacy LED concern.

Sakari's change - 
https://lore.kernel.org/lkml/20211018121729.6357-1-sakari.ailus@linux.intel.com/
which add the support device probe in non-zero ACPI D state.

This following patch add support probe in non-zero ACPI D state for more camera
sensors: ov2740, ov5670, ov5675, ov8856, imx208 and hi556.

--

This patch series is based on linux-next branch of Rafael J. Wysocki's
linux-pm git repository:
https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git

--

Bingbu Cao (5):
  media: ov8856: support device probe in non-zero ACPI D state
  media: ov2740: support device probe in non-zero ACPI D state
  media: imx208: Support device probe in non-zero ACPI D state
  media: ov5675: Support device probe in non-zero ACPI D state
  media: hi556: Support device probe in non-zero ACPI D state

Sakari Ailus (1):
  media: ov5670: Support device probe in non-zero ACPI D state

 drivers/media/i2c/hi556.c  |  70 +++++++++++++-------
 drivers/media/i2c/imx208.c |  82 +++++++++++++++--------
 drivers/media/i2c/ov2740.c |  69 ++++++++++++-------
 drivers/media/i2c/ov5670.c |  78 +++++++++++++---------
 drivers/media/i2c/ov5675.c |  71 +++++++++++++-------
 drivers/media/i2c/ov8856.c | 162 +++++++++++++++++++++++++--------------------
 6 files changed, 324 insertions(+), 208 deletions(-)

-- 
2.7.4

[PATCH v2 1/6] media: ov8856: support device probe in non-zero ACPI D state

[Bingbu Cao]

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

[PATCH v2 2/6] media: ov5670: Support device probe in non-zero ACPI D state

[Bingbu Cao]

From: Sakari Ailus <sakari.ailus@linux.intel.com>

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>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 drivers/media/i2c/ov5670.c | 78 +++++++++++++++++++++++++++-------------------
 1 file changed, 46 insertions(+), 32 deletions(-)

diff --git a/drivers/media/i2c/ov5670.c b/drivers/media/i2c/ov5670.c
index 251f459ab484..5adf73cb88d4 100644
--- a/drivers/media/i2c/ov5670.c
+++ b/drivers/media/i2c/ov5670.c
@@ -1833,6 +1833,8 @@ struct ov5670 {
 
 	/* Streaming on/off */
 	bool streaming;
+	/* True if the device has been identified */
+	bool identified;
 };
 
 #define to_ov5670(_sd)	container_of(_sd, struct ov5670, sd)
@@ -2273,6 +2275,32 @@ static int ov5670_get_skip_frames(struct v4l2_subdev *sd, u32 *frames)
 	return 0;
 }
 
+/* Verify chip ID */
+static int ov5670_identify_module(struct ov5670 *ov5670)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&ov5670->sd);
+	int ret;
+	u32 val;
+
+	if (ov5670->identified)
+		return 0;
+
+	ret = ov5670_read_reg(ov5670, OV5670_REG_CHIP_ID,
+			      OV5670_REG_VALUE_24BIT, &val);
+	if (ret)
+		return ret;
+
+	if (val != OV5670_CHIP_ID) {
+		dev_err(&client->dev, "chip id mismatch: %x!=%x\n",
+			OV5670_CHIP_ID, val);
+		return -ENXIO;
+	}
+
+	ov5670->identified = true;
+
+	return 0;
+}
+
 /* Prepare streaming by writing default values and customized values */
 static int ov5670_start_streaming(struct ov5670 *ov5670)
 {
@@ -2281,6 +2309,10 @@ static int ov5670_start_streaming(struct ov5670 *ov5670)
 	int link_freq_index;
 	int ret;
 
+	ret = ov5670_identify_module(ov5670);
+	if (ret)
+		return ret;
+
 	/* Get out of from software reset */
 	ret = ov5670_write_reg(ov5670, OV5670_REG_SOFTWARE_RST,
 			       OV5670_REG_VALUE_08BIT, OV5670_SOFTWARE_RST);
@@ -2400,27 +2432,6 @@ static int __maybe_unused ov5670_resume(struct device *dev)
 	return 0;
 }
 
-/* Verify chip ID */
-static int ov5670_identify_module(struct ov5670 *ov5670)
-{
-	struct i2c_client *client = v4l2_get_subdevdata(&ov5670->sd);
-	int ret;
-	u32 val;
-
-	ret = ov5670_read_reg(ov5670, OV5670_REG_CHIP_ID,
-			      OV5670_REG_VALUE_24BIT, &val);
-	if (ret)
-		return ret;
-
-	if (val != OV5670_CHIP_ID) {
-		dev_err(&client->dev, "chip id mismatch: %x!=%x\n",
-			OV5670_CHIP_ID, val);
-		return -ENXIO;
-	}
-
-	return 0;
-}
-
 static const struct v4l2_subdev_core_ops ov5670_core_ops = {
 	.log_status = v4l2_ctrl_subdev_log_status,
 	.subscribe_event = v4l2_ctrl_subdev_subscribe_event,
@@ -2462,6 +2473,7 @@ static int ov5670_probe(struct i2c_client *client)
 	struct ov5670 *ov5670;
 	const char *err_msg;
 	u32 input_clk = 0;
+	bool full_power;
 	int ret;
 
 	device_property_read_u32(&client->dev, "clock-frequency", &input_clk);
@@ -2478,11 +2490,14 @@ static int ov5670_probe(struct i2c_client *client)
 	/* Initialize subdev */
 	v4l2_i2c_subdev_init(&ov5670->sd, client, &ov5670_subdev_ops);
 
-	/* Check module identity */
-	ret = ov5670_identify_module(ov5670);
-	if (ret) {
-		err_msg = "ov5670_identify_module() error";
-		goto error_print;
+	full_power = acpi_dev_state_d0(&client->dev);
+	if (full_power) {
+		/* Check module identity */
+		ret = ov5670_identify_module(ov5670);
+		if (ret) {
+			err_msg = "ov5670_identify_module() error";
+			goto error_print;
+		}
 	}
 
 	mutex_init(&ov5670->mutex);
@@ -2519,11 +2534,9 @@ static int ov5670_probe(struct i2c_client *client)
 
 	ov5670->streaming = false;
 
-	/*
-	 * 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);
 
@@ -2565,7 +2578,7 @@ static const struct dev_pm_ops ov5670_pm_ops = {
 
 #ifdef CONFIG_ACPI
 static const struct acpi_device_id ov5670_acpi_ids[] = {
-	{"INT3479"},
+	{ "INT3479" },
 	{ /* sentinel */ }
 };
 
@@ -2580,6 +2593,7 @@ static struct i2c_driver ov5670_i2c_driver = {
 	},
 	.probe_new = ov5670_probe,
 	.remove = ov5670_remove,
+	.flags = I2C_DRV_ACPI_WAIVE_D0_PROBE,
 };
 
 module_i2c_driver(ov5670_i2c_driver);
-- 
2.7.4

[PATCH v2 3/6] media: ov2740: support device probe in non-zero ACPI D state

[Bingbu Cao]

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/ov2740.c | 69 ++++++++++++++++++++++++++++++----------------
 1 file changed, 45 insertions(+), 24 deletions(-)

diff --git a/drivers/media/i2c/ov2740.c b/drivers/media/i2c/ov2740.c
index 934c9d65cb09..bab720c7c1de 100644
--- a/drivers/media/i2c/ov2740.c
+++ b/drivers/media/i2c/ov2740.c
@@ -345,6 +345,9 @@ struct ov2740 {
 
 	/* NVM data inforamtion */
 	struct nvm_data *nvm;
+
+	/* True if the device has been identified */
+	bool identified;
 };
 
 static inline struct ov2740 *to_ov2740(struct v4l2_subdev *subdev)
@@ -440,6 +443,30 @@ static int ov2740_write_reg_list(struct ov2740 *ov2740,
 	return 0;
 }
 
+static int ov2740_identify_module(struct ov2740 *ov2740)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&ov2740->sd);
+	int ret;
+	u32 val;
+
+	if (ov2740->identified)
+		return 0;
+
+	ret = ov2740_read_reg(ov2740, OV2740_REG_CHIP_ID, 3, &val);
+	if (ret)
+		return ret;
+
+	if (val != OV2740_CHIP_ID) {
+		dev_err(&client->dev, "chip id mismatch: %x!=%x",
+			OV2740_CHIP_ID, val);
+		return -ENXIO;
+	}
+
+	ov2740->identified = true;
+
+	return 0;
+}
+
 static int ov2740_update_digital_gain(struct ov2740 *ov2740, u32 d_gain)
 {
 	int ret = 0;
@@ -724,6 +751,10 @@ static int ov2740_start_streaming(struct ov2740 *ov2740)
 	int link_freq_index;
 	int ret = 0;
 
+	ret = ov2740_identify_module(ov2740);
+	if (ret)
+		return ret;
+
 	ov2740_load_otp_data(nvm);
 
 	link_freq_index = ov2740->cur_mode->link_freq_index;
@@ -956,25 +987,6 @@ static const struct v4l2_subdev_internal_ops ov2740_internal_ops = {
 	.open = ov2740_open,
 };
 
-static int ov2740_identify_module(struct ov2740 *ov2740)
-{
-	struct i2c_client *client = v4l2_get_subdevdata(&ov2740->sd);
-	int ret;
-	u32 val;
-
-	ret = ov2740_read_reg(ov2740, OV2740_REG_CHIP_ID, 3, &val);
-	if (ret)
-		return ret;
-
-	if (val != OV2740_CHIP_ID) {
-		dev_err(&client->dev, "chip id mismatch: %x!=%x",
-			OV2740_CHIP_ID, val);
-		return -ENXIO;
-	}
-
-	return 0;
-}
-
 static int ov2740_check_hwcfg(struct device *dev)
 {
 	struct fwnode_handle *ep;
@@ -1137,6 +1149,7 @@ static int ov2740_probe(struct i2c_client *client)
 {
 	struct ov2740 *ov2740;
 	int ret = 0;
+	bool full_power;
 
 	ret = ov2740_check_hwcfg(&client->dev);
 	if (ret) {
@@ -1149,6 +1162,15 @@ static int ov2740_probe(struct i2c_client *client)
 	if (!ov2740)
 		return -ENOMEM;
 
+	full_power = acpi_dev_state_d0(&client->dev);
+	if (full_power) {
+		ret = ov2740_identify_module(ov2740);
+		if (ret) {
+			dev_err(&client->dev, "failed to find sensor: %d", ret);
+			return ret;
+		}
+	}
+
 	v4l2_i2c_subdev_init(&ov2740->sd, client, &ov2740_subdev_ops);
 	ret = ov2740_identify_module(ov2740);
 	if (ret) {
@@ -1186,11 +1208,9 @@ static int ov2740_probe(struct i2c_client *client)
 	if (ret)
 		dev_warn(&client->dev, "register nvmem failed, ret %d\n", ret);
 
-	/*
-	 * 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);
 
@@ -1225,6 +1245,7 @@ static struct i2c_driver ov2740_i2c_driver = {
 	},
 	.probe_new = ov2740_probe,
 	.remove = ov2740_remove,
+	.flags = I2C_DRV_ACPI_WAIVE_D0_PROBE,
 };
 
 module_i2c_driver(ov2740_i2c_driver);
-- 
2.7.4

[PATCH v2 4/6] media: imx208: Support device probe in non-zero ACPI D state

[Bingbu Cao]

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/imx208.c | 82 ++++++++++++++++++++++++++++++----------------
 1 file changed, 53 insertions(+), 29 deletions(-)

diff --git a/drivers/media/i2c/imx208.c b/drivers/media/i2c/imx208.c
index 6f3d9c1b5879..b9516b2f1c15 100644
--- a/drivers/media/i2c/imx208.c
+++ b/drivers/media/i2c/imx208.c
@@ -296,6 +296,9 @@ struct imx208 {
 	/* OTP data */
 	bool otp_read;
 	char otp_data[IMX208_OTP_SIZE];
+
+	/* True if the device has been identified */
+	bool identified;
 };
 
 static inline struct imx208 *to_imx208(struct v4l2_subdev *_sd)
@@ -619,6 +622,34 @@ static int imx208_set_pad_format(struct v4l2_subdev *sd,
 	return 0;
 }
 
+static int imx208_identify_module(struct imx208 *imx208)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&imx208->sd);
+	int ret;
+	u32 val;
+
+	if (imx208->identified)
+		return 0;
+
+	ret = imx208_read_reg(imx208, IMX208_REG_CHIP_ID,
+			      2, &val);
+	if (ret) {
+		dev_err(&client->dev, "failed to read chip id %x\n",
+			IMX208_CHIP_ID);
+		return ret;
+	}
+
+	if (val != IMX208_CHIP_ID) {
+		dev_err(&client->dev, "chip id mismatch: %x!=%x\n",
+			IMX208_CHIP_ID, val);
+		return -EIO;
+	}
+
+	imx208->identified = true;
+
+	return 0;
+}
+
 /* Start streaming */
 static int imx208_start_streaming(struct imx208 *imx208)
 {
@@ -626,6 +657,10 @@ static int imx208_start_streaming(struct imx208 *imx208)
 	const struct imx208_reg_list *reg_list;
 	int ret, link_freq_index;
 
+	ret = imx208_identify_module(imx208);
+	if (ret)
+		return ret;
+
 	/* Setup PLL */
 	link_freq_index = imx208->cur_mode->link_freq_index;
 	reg_list = &link_freq_configs[link_freq_index].reg_list;
@@ -752,29 +787,6 @@ static int __maybe_unused imx208_resume(struct device *dev)
 }
 
 /* Verify chip ID */
-static int imx208_identify_module(struct imx208 *imx208)
-{
-	struct i2c_client *client = v4l2_get_subdevdata(&imx208->sd);
-	int ret;
-	u32 val;
-
-	ret = imx208_read_reg(imx208, IMX208_REG_CHIP_ID,
-			      2, &val);
-	if (ret) {
-		dev_err(&client->dev, "failed to read chip id %x\n",
-			IMX208_CHIP_ID);
-		return ret;
-	}
-
-	if (val != IMX208_CHIP_ID) {
-		dev_err(&client->dev, "chip id mismatch: %x!=%x\n",
-			IMX208_CHIP_ID, val);
-		return -EIO;
-	}
-
-	return 0;
-}
-
 static const struct v4l2_subdev_video_ops imx208_video_ops = {
 	.s_stream = imx208_set_stream,
 };
@@ -813,6 +825,10 @@ static int imx208_read_otp(struct imx208 *imx208)
 		goto out_unlock;
 	}
 
+	ret = imx208_identify_module(imx208);
+	if (ret)
+		goto out_pm_put;
+
 	/* Write register address */
 	msgs[0].addr = client->addr;
 	msgs[0].flags = 0;
@@ -831,6 +847,7 @@ static int imx208_read_otp(struct imx208 *imx208)
 		ret = 0;
 	}
 
+out_pm_put:
 	pm_runtime_put(&client->dev);
 
 out_unlock:
@@ -961,6 +978,7 @@ static int imx208_probe(struct i2c_client *client)
 {
 	struct imx208 *imx208;
 	int ret;
+	bool full_power;
 	u32 val = 0;
 
 	device_property_read_u32(&client->dev, "clock-frequency", &val);
@@ -978,11 +996,14 @@ static int imx208_probe(struct i2c_client *client)
 	/* Initialize subdev */
 	v4l2_i2c_subdev_init(&imx208->sd, client, &imx208_subdev_ops);
 
-	/* Check module identity */
-	ret = imx208_identify_module(imx208);
-	if (ret) {
-		dev_err(&client->dev, "failed to find sensor: %d", ret);
-		goto error_probe;
+	full_power = acpi_dev_state_d0(&client->dev);
+	if (full_power) {
+		/* Check module identity */
+		ret = imx208_identify_module(imx208);
+		if (ret) {
+			dev_err(&client->dev, "failed to find sensor: %d", ret);
+			goto error_probe;
+		}
 	}
 
 	/* Set default mode to max resolution */
@@ -1017,7 +1038,9 @@ static int imx208_probe(struct i2c_client *client)
 		goto error_async_subdev;
 	}
 
-	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);
 
@@ -1077,6 +1100,7 @@ static struct i2c_driver imx208_i2c_driver = {
 	},
 	.probe_new = imx208_probe,
 	.remove = imx208_remove,
+	.flags = I2C_DRV_ACPI_WAIVE_D0_PROBE,
 };
 
 module_i2c_driver(imx208_i2c_driver);
-- 
2.7.4

[PATCH v2 5/6] media: ov5675: Support device probe in non-zero ACPI D state

[Bingbu Cao]

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/ov5675.c | 71 ++++++++++++++++++++++++++++++----------------
 1 file changed, 46 insertions(+), 25 deletions(-)

diff --git a/drivers/media/i2c/ov5675.c b/drivers/media/i2c/ov5675.c
index da5850b7ad07..00925850fa7c 100644
--- a/drivers/media/i2c/ov5675.c
+++ b/drivers/media/i2c/ov5675.c
@@ -493,6 +493,9 @@ struct ov5675 {
 
 	/* Streaming on/off */
 	bool streaming;
+
+	/* True if the device has been identified */
+	bool identified;
 };
 
 static u64 to_pixel_rate(u32 f_index)
@@ -808,12 +811,41 @@ static void ov5675_update_pad_format(const struct ov5675_mode *mode,
 	fmt->field = V4L2_FIELD_NONE;
 }
 
+static int ov5675_identify_module(struct ov5675 *ov5675)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&ov5675->sd);
+	int ret;
+	u32 val;
+
+	if (ov5675->identified)
+		return 0;
+
+	ret = ov5675_read_reg(ov5675, OV5675_REG_CHIP_ID,
+			      OV5675_REG_VALUE_24BIT, &val);
+	if (ret)
+		return ret;
+
+	if (val != OV5675_CHIP_ID) {
+		dev_err(&client->dev, "chip id mismatch: %x!=%x",
+			OV5675_CHIP_ID, val);
+		return -ENXIO;
+	}
+
+	ov5675->identified = true;
+
+	return 0;
+}
+
 static int ov5675_start_streaming(struct ov5675 *ov5675)
 {
 	struct i2c_client *client = v4l2_get_subdevdata(&ov5675->sd);
 	const struct ov5675_reg_list *reg_list;
 	int link_freq_index, ret;
 
+	ret = ov5675_identify_module(ov5675);
+	if (ret)
+		return ret;
+
 	link_freq_index = ov5675->cur_mode->link_freq_index;
 	reg_list = &link_freq_configs[link_freq_index].reg_list;
 	ret = ov5675_write_reg_list(ov5675, reg_list);
@@ -1048,26 +1080,6 @@ static const struct v4l2_subdev_internal_ops ov5675_internal_ops = {
 	.open = ov5675_open,
 };
 
-static int ov5675_identify_module(struct ov5675 *ov5675)
-{
-	struct i2c_client *client = v4l2_get_subdevdata(&ov5675->sd);
-	int ret;
-	u32 val;
-
-	ret = ov5675_read_reg(ov5675, OV5675_REG_CHIP_ID,
-			      OV5675_REG_VALUE_24BIT, &val);
-	if (ret)
-		return ret;
-
-	if (val != OV5675_CHIP_ID) {
-		dev_err(&client->dev, "chip id mismatch: %x!=%x",
-			OV5675_CHIP_ID, val);
-		return -ENXIO;
-	}
-
-	return 0;
-}
-
 static int ov5675_check_hwcfg(struct device *dev)
 {
 	struct fwnode_handle *ep;
@@ -1154,6 +1166,7 @@ static int ov5675_remove(struct i2c_client *client)
 static int ov5675_probe(struct i2c_client *client)
 {
 	struct ov5675 *ov5675;
+	bool full_power;
 	int ret;
 
 	ret = ov5675_check_hwcfg(&client->dev);
@@ -1168,10 +1181,14 @@ static int ov5675_probe(struct i2c_client *client)
 		return -ENOMEM;
 
 	v4l2_i2c_subdev_init(&ov5675->sd, client, &ov5675_subdev_ops);
-	ret = ov5675_identify_module(ov5675);
-	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 = ov5675_identify_module(ov5675);
+		if (ret) {
+			dev_err(&client->dev, "failed to find sensor: %d", ret);
+			return ret;
+		}
 	}
 
 	mutex_init(&ov5675->mutex);
@@ -1204,7 +1221,10 @@ static int ov5675_probe(struct i2c_client *client)
 	 * 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);
 
@@ -1241,6 +1261,7 @@ static struct i2c_driver ov5675_i2c_driver = {
 	},
 	.probe_new = ov5675_probe,
 	.remove = ov5675_remove,
+	.flags = I2C_DRV_ACPI_WAIVE_D0_PROBE,
 };
 
 module_i2c_driver(ov5675_i2c_driver);
-- 
2.7.4

[PATCH v2 6/6] media: hi556: Support device probe in non-zero ACPI D state

[Bingbu Cao]

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>
Signed-off-by: Kao, Arec <arec.kao@intel.com>
---
 drivers/media/i2c/hi556.c | 70 ++++++++++++++++++++++++++++++-----------------
 1 file changed, 45 insertions(+), 25 deletions(-)

diff --git a/drivers/media/i2c/hi556.c b/drivers/media/i2c/hi556.c
index 8db1cbedc1fd..055d1aa8410e 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 +760,41 @@ 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;
+
+	if (hi556->identified)
+		return 0;
+
+	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 +1033,6 @@ 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 +1118,7 @@ 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 +1133,14 @@ 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 +1169,9 @@ 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 +1208,7 @@ 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