[v7 00/11] Add support for ast2600 ADC

[v7 00/11] Add support for ast2600 ADC

[Billy Tsai]

This patch serials make aspeed_adc.c can support ast2600 and backward
compatible.

Change since v6:
aspeed_adc.c:
 - Fix the parameter error for aspeed_adc_unregister_fixed_divider.

Change since v5:
aspeed_adc.c:
  - Use devm_clk_hw_register_divider()
  - Enabling and setting the ADC to normal mode is a necessary flow, so
  take it out of the condition.

Change since v4:
dt-bindings:
  - Add clocks maxItems.
  - Rename the property to meet the property-units.yaml.
  - Add the description for the difference between adc0 and adc1.
aspeed_adc.c:
  - Use new property name to get internal reference voltage: units from mv
  to uv.
  - Fix -Wnonnull warning caused by snprintf parameters.
  - Add suffix mv to the vref parameters.
  - Use ARRAY_SIZE instead of 32.
  - Add a reset action for ADC power down and Use devm_iio_device_register.
  - Fix typo error.
  - Separate the offset interface of ch7 when battery sensing enable

Change since v3:
dt-bindings:
  - Fix properties:aspeed,int_vref_mv type error.

Change since v2:
dt-bindings:
  - Create a new dt-bindings for ast2600 adc
aspeed_adc.c:
  - Splits the patch for more details
  - Remove version enum and use the flags in model data to distinguish
  hardware feature
  - Support trimming data get and set.
  - Use devm_add_action_or_reset to simplify probe error handling.

Changes since v1:
dt-bindings:
  - Fix the aspeed,adc.yaml check error.
  - Add battery-sensing property.
aspeed_adc.c:
  - Change the init flow:
    Clock and reference voltage setting should be completed before adc
    engine enable.
  - Change the default sampling rate to meet most user case.
  - Add patch #8 to suppoert battery sensing mode.

Billy Tsai (11):
  iio: adc: aspeed: Keep model data to driver data.
  iio: adc: aspeed: Restructure the model data
  iio: adc: aspeed: Add vref config function
  iio: adc: aspeed: Use model_data to set clk scaler.
  iio: adc: aspeed: Use devm_add_action_or_reset.
  iio: adc: aspeed: Support ast2600 adc.
  iio: adc: aspeed: Fix the calculate error of clock.
  iio: adc: aspeed: Add func to set sampling rate.
  iio: adc: aspeed: Add compensation phase.
  iio: adc: aspeed: Support battery sensing.
  iio: adc: aspeed: Get and set trimming data.

 drivers/iio/adc/aspeed_adc.c | 554 +++++++++++++++++++++++++++++------
 1 file changed, 459 insertions(+), 95 deletions(-)

-- 
2.25.1

[v7 01/11] iio: adc: aspeed: Keep model data to driver data.

[Billy Tsai]

Keep the model data pointer to driver data for reducing the usage of
of_device_get_match_data().

Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
---
 drivers/iio/adc/aspeed_adc.c | 20 +++++++-------------
 1 file changed, 7 insertions(+), 13 deletions(-)

diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
index f055fe7b2c40..76ae1c3f584b 100644
--- a/drivers/iio/adc/aspeed_adc.c
+++ b/drivers/iio/adc/aspeed_adc.c
@@ -77,6 +77,7 @@ struct aspeed_adc_model_data {
 
 struct aspeed_adc_data {
 	struct device		*dev;
+	const struct aspeed_adc_model_data *model_data;
 	void __iomem		*base;
 	spinlock_t		clk_lock;
 	struct clk_hw		*clk_prescaler;
@@ -118,8 +119,6 @@ static int aspeed_adc_read_raw(struct iio_dev *indio_dev,
 			       int *val, int *val2, long mask)
 {
 	struct aspeed_adc_data *data = iio_priv(indio_dev);
-	const struct aspeed_adc_model_data *model_data =
-			of_device_get_match_data(data->dev);
 
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
@@ -127,7 +126,7 @@ static int aspeed_adc_read_raw(struct iio_dev *indio_dev,
 		return IIO_VAL_INT;
 
 	case IIO_CHAN_INFO_SCALE:
-		*val = model_data->vref_voltage;
+		*val = data->model_data->vref_voltage;
 		*val2 = ASPEED_RESOLUTION_BITS;
 		return IIO_VAL_FRACTIONAL_LOG2;
 
@@ -146,13 +145,11 @@ static int aspeed_adc_write_raw(struct iio_dev *indio_dev,
 				int val, int val2, long mask)
 {
 	struct aspeed_adc_data *data = iio_priv(indio_dev);
-	const struct aspeed_adc_model_data *model_data =
-			of_device_get_match_data(data->dev);
 
 	switch (mask) {
 	case IIO_CHAN_INFO_SAMP_FREQ:
-		if (val < model_data->min_sampling_rate ||
-			val > model_data->max_sampling_rate)
+		if (val < data->model_data->min_sampling_rate ||
+			val > data->model_data->max_sampling_rate)
 			return -EINVAL;
 
 		clk_set_rate(data->clk_scaler->clk,
@@ -198,7 +195,6 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 {
 	struct iio_dev *indio_dev;
 	struct aspeed_adc_data *data;
-	const struct aspeed_adc_model_data *model_data;
 	const char *clk_parent_name;
 	int ret;
 	u32 adc_engine_control_reg_val;
@@ -209,6 +205,7 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 
 	data = iio_priv(indio_dev);
 	data->dev = &pdev->dev;
+	data->model_data = of_device_get_match_data(&pdev->dev);
 	platform_set_drvdata(pdev, indio_dev);
 
 	data->base = devm_platform_ioremap_resource(pdev, 0);
@@ -249,9 +246,7 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 	}
 	reset_control_deassert(data->rst);
 
-	model_data = of_device_get_match_data(&pdev->dev);
-
-	if (model_data->wait_init_sequence) {
+	if (data->model_data->wait_init_sequence) {
 		/* Enable engine in normal mode. */
 		writel(FIELD_PREP(ASPEED_ADC_OP_MODE,
 				  ASPEED_ADC_OP_MODE_NORMAL) |
@@ -281,8 +276,7 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 	writel(adc_engine_control_reg_val,
 	       data->base + ASPEED_REG_ENGINE_CONTROL);
 
-	model_data = of_device_get_match_data(&pdev->dev);
-	indio_dev->name = model_data->model_name;
+	indio_dev->name = data->model_data->model_name;
 	indio_dev->info = &aspeed_adc_iio_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = aspeed_adc_iio_channels;
-- 
2.25.1

[v7 02/11] iio: adc: aspeed: Restructure the model data

[Billy Tsai]

This patch refactors the model data structure to distinguish the
function form different versions of aspeed ADC.
- Rename the vref_voltage to vref_fixed_mv and add vref_mv driver data
When driver probe will check vref_fixed_mv value and store it to vref_mv
which isn't const value.
- Add num_channels
Make num_channles of iio device can be changed by different model_data
- Add need_prescaler flag and scaler_bit_width
The need_prescaler flag is used to tell the driver the clock divider needs
another Prescaler and the scaler_bit_width to set the clock divider
bitfield width.

Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
---
 drivers/iio/adc/aspeed_adc.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
index 76ae1c3f584b..cc808ec89a0f 100644
--- a/drivers/iio/adc/aspeed_adc.c
+++ b/drivers/iio/adc/aspeed_adc.c
@@ -71,8 +71,11 @@ struct aspeed_adc_model_data {
 	const char *model_name;
 	unsigned int min_sampling_rate;	// Hz
 	unsigned int max_sampling_rate;	// Hz
-	unsigned int vref_voltage;	// mV
+	unsigned int vref_fixed_mv;
 	bool wait_init_sequence;
+	bool need_prescaler;
+	u8 scaler_bit_width;
+	unsigned int num_channels;
 };
 
 struct aspeed_adc_data {
@@ -83,6 +86,7 @@ struct aspeed_adc_data {
 	struct clk_hw		*clk_prescaler;
 	struct clk_hw		*clk_scaler;
 	struct reset_control	*rst;
+	int			vref_mv;
 };
 
 #define ASPEED_CHAN(_idx, _data_reg_addr) {			\
@@ -126,7 +130,7 @@ static int aspeed_adc_read_raw(struct iio_dev *indio_dev,
 		return IIO_VAL_INT;
 
 	case IIO_CHAN_INFO_SCALE:
-		*val = data->model_data->vref_voltage;
+		*val = data->model_data->vref_fixed_mv;
 		*val2 = ASPEED_RESOLUTION_BITS;
 		return IIO_VAL_FRACTIONAL_LOG2;
 
@@ -280,7 +284,7 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 	indio_dev->info = &aspeed_adc_iio_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = aspeed_adc_iio_channels;
-	indio_dev->num_channels = ARRAY_SIZE(aspeed_adc_iio_channels);
+	indio_dev->num_channels = data->model_data->num_channels;
 
 	ret = iio_device_register(indio_dev);
 	if (ret)
@@ -320,17 +324,23 @@ static int aspeed_adc_remove(struct platform_device *pdev)
 
 static const struct aspeed_adc_model_data ast2400_model_data = {
 	.model_name = "ast2400-adc",
-	.vref_voltage = 2500, // mV
+	.vref_fixed_mv = 2500,
 	.min_sampling_rate = 10000,
 	.max_sampling_rate = 500000,
+	.need_prescaler = true,
+	.scaler_bit_width = 10,
+	.num_channels = 16,
 };
 
 static const struct aspeed_adc_model_data ast2500_model_data = {
 	.model_name = "ast2500-adc",
-	.vref_voltage = 1800, // mV
+	.vref_fixed_mv = 1800,
 	.min_sampling_rate = 1,
 	.max_sampling_rate = 1000000,
 	.wait_init_sequence = true,
+	.need_prescaler = true,
+	.scaler_bit_width = 10,
+	.num_channels = 16,
 };
 
 static const struct of_device_id aspeed_adc_matches[] = {
-- 
2.25.1

[v7 03/11] iio: adc: aspeed: Add vref config function

[Billy Tsai]

Add the function to check the vref_fixed_mv and set the value to driver
data.

Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
---
 drivers/iio/adc/aspeed_adc.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
index cc808ec89a0f..aec335956310 100644
--- a/drivers/iio/adc/aspeed_adc.c
+++ b/drivers/iio/adc/aspeed_adc.c
@@ -130,7 +130,7 @@ static int aspeed_adc_read_raw(struct iio_dev *indio_dev,
 		return IIO_VAL_INT;
 
 	case IIO_CHAN_INFO_SCALE:
-		*val = data->model_data->vref_fixed_mv;
+		*val = data->vref_mv;
 		*val2 = ASPEED_RESOLUTION_BITS;
 		return IIO_VAL_FRACTIONAL_LOG2;
 
@@ -195,6 +195,17 @@ static const struct iio_info aspeed_adc_iio_info = {
 	.debugfs_reg_access = aspeed_adc_reg_access,
 };
 
+static int aspeed_adc_vref_config(struct iio_dev *indio_dev)
+{
+	struct aspeed_adc_data *data = iio_priv(indio_dev);
+
+	if (data->model_data->vref_fixed_mv) {
+		data->vref_mv = data->model_data->vref_fixed_mv;
+		return 0;
+	}
+	return 0;
+}
+
 static int aspeed_adc_probe(struct platform_device *pdev)
 {
 	struct iio_dev *indio_dev;
@@ -250,6 +261,10 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 	}
 	reset_control_deassert(data->rst);
 
+	ret = aspeed_adc_vref_config(indio_dev);
+	if (ret)
+		goto vref_config_error;
+
 	if (data->model_data->wait_init_sequence) {
 		/* Enable engine in normal mode. */
 		writel(FIELD_PREP(ASPEED_ADC_OP_MODE,
@@ -298,6 +313,7 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 	clk_disable_unprepare(data->clk_scaler->clk);
 clk_enable_error:
 poll_timeout_error:
+vref_config_error:
 	reset_control_assert(data->rst);
 reset_error:
 	clk_hw_unregister_divider(data->clk_scaler);
-- 
2.25.1

[v7 04/11] iio: adc: aspeed: Use model_data to set clk scaler.

[Billy Tsai]

This patch uses need_prescaler and scaler_bit_width to set the ADC clock
scaler.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
---
 drivers/iio/adc/aspeed_adc.c | 43 ++++++++++++++++++++++--------------
 1 file changed, 27 insertions(+), 16 deletions(-)

diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
index aec335956310..e53d1541ad1d 100644
--- a/drivers/iio/adc/aspeed_adc.c
+++ b/drivers/iio/adc/aspeed_adc.c
@@ -210,9 +210,10 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 {
 	struct iio_dev *indio_dev;
 	struct aspeed_adc_data *data;
-	const char *clk_parent_name;
 	int ret;
 	u32 adc_engine_control_reg_val;
+	unsigned long scaler_flags = 0;
+	char clk_name[32], clk_parent_name[32];
 
 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*data));
 	if (!indio_dev)
@@ -229,24 +230,32 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 
 	/* Register ADC clock prescaler with source specified by device tree. */
 	spin_lock_init(&data->clk_lock);
-	clk_parent_name = of_clk_get_parent_name(pdev->dev.of_node, 0);
-
-	data->clk_prescaler = clk_hw_register_divider(
-				&pdev->dev, "prescaler", clk_parent_name, 0,
-				data->base + ASPEED_REG_CLOCK_CONTROL,
-				17, 15, 0, &data->clk_lock);
-	if (IS_ERR(data->clk_prescaler))
-		return PTR_ERR(data->clk_prescaler);
-
+	snprintf(clk_parent_name, ARRAY_SIZE(clk_parent_name), "%s",
+		 of_clk_get_parent_name(pdev->dev.of_node, 0));
+
+	if (data->model_data->need_prescaler) {
+		snprintf(clk_name, ARRAY_SIZE(clk_name), "%s-prescaler",
+			 data->model_data->model_name);
+		data->clk_prescaler = clk_hw_register_divider(
+			&pdev->dev, clk_name, clk_parent_name, 0,
+			data->base + ASPEED_REG_CLOCK_CONTROL, 17, 15, 0,
+			&data->clk_lock);
+		if (IS_ERR(data->clk_prescaler))
+			return PTR_ERR(data->clk_prescaler);
+		snprintf(clk_parent_name, ARRAY_SIZE(clk_parent_name),
+			 clk_name);
+		scaler_flags = CLK_SET_RATE_PARENT;
+	}
 	/*
 	 * Register ADC clock scaler downstream from the prescaler. Allow rate
 	 * setting to adjust the prescaler as well.
 	 */
+	snprintf(clk_name, ARRAY_SIZE(clk_name), "%s-scaler",
+		 data->model_data->model_name);
 	data->clk_scaler = clk_hw_register_divider(
-				&pdev->dev, "scaler", "prescaler",
-				CLK_SET_RATE_PARENT,
-				data->base + ASPEED_REG_CLOCK_CONTROL,
-				0, 10, 0, &data->clk_lock);
+		&pdev->dev, clk_name, clk_parent_name, scaler_flags,
+		data->base + ASPEED_REG_CLOCK_CONTROL, 0,
+		data->model_data->scaler_bit_width, 0, &data->clk_lock);
 	if (IS_ERR(data->clk_scaler)) {
 		ret = PTR_ERR(data->clk_scaler);
 		goto scaler_error;
@@ -318,7 +327,8 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 reset_error:
 	clk_hw_unregister_divider(data->clk_scaler);
 scaler_error:
-	clk_hw_unregister_divider(data->clk_prescaler);
+	if (data->model_data->need_prescaler)
+		clk_hw_unregister_divider(data->clk_prescaler);
 	return ret;
 }
 
@@ -333,7 +343,8 @@ static int aspeed_adc_remove(struct platform_device *pdev)
 	clk_disable_unprepare(data->clk_scaler->clk);
 	reset_control_assert(data->rst);
 	clk_hw_unregister_divider(data->clk_scaler);
-	clk_hw_unregister_divider(data->clk_prescaler);
+	if (data->model_data->need_prescaler)
+		clk_hw_unregister_divider(data->clk_prescaler);
 
 	return 0;
 }
-- 
2.25.1

[v7 05/11] iio: adc: aspeed: Use devm_add_action_or_reset.

[Billy Tsai]

This patch use devm_add_action_or_reset to handle the error in probe
phase.

Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
---
 drivers/iio/adc/aspeed_adc.c | 113 +++++++++++++++++------------------
 1 file changed, 55 insertions(+), 58 deletions(-)

diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
index e53d1541ad1d..0a18893c47f0 100644
--- a/drivers/iio/adc/aspeed_adc.c
+++ b/drivers/iio/adc/aspeed_adc.c
@@ -195,6 +195,28 @@ static const struct iio_info aspeed_adc_iio_info = {
 	.debugfs_reg_access = aspeed_adc_reg_access,
 };
 
+static void aspeed_adc_reset_assert(void *data)
+{
+	struct reset_control *rst = data;
+
+	reset_control_assert(rst);
+}
+
+static void aspeed_adc_clk_disable_unprepare(void *data)
+{
+	struct clk *clk = data;
+
+	clk_disable_unprepare(clk);
+}
+
+static void aspeed_adc_power_down(void *data)
+{
+	struct aspeed_adc_data *priv_data = data;
+
+	writel(FIELD_PREP(ASPEED_ADC_OP_MODE, ASPEED_ADC_OP_MODE_PWR_DOWN),
+	       priv_data->base + ASPEED_REG_ENGINE_CONTROL);
+}
+
 static int aspeed_adc_vref_config(struct iio_dev *indio_dev)
 {
 	struct aspeed_adc_data *data = iio_priv(indio_dev);
@@ -236,7 +258,7 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 	if (data->model_data->need_prescaler) {
 		snprintf(clk_name, ARRAY_SIZE(clk_name), "%s-prescaler",
 			 data->model_data->model_name);
-		data->clk_prescaler = clk_hw_register_divider(
+		data->clk_prescaler = devm_clk_hw_register_divider(
 			&pdev->dev, clk_name, clk_parent_name, 0,
 			data->base + ASPEED_REG_CLOCK_CONTROL, 17, 15, 0,
 			&data->clk_lock);
@@ -252,35 +274,41 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 	 */
 	snprintf(clk_name, ARRAY_SIZE(clk_name), "%s-scaler",
 		 data->model_data->model_name);
-	data->clk_scaler = clk_hw_register_divider(
+	data->clk_scaler = devm_clk_hw_register_divider(
 		&pdev->dev, clk_name, clk_parent_name, scaler_flags,
 		data->base + ASPEED_REG_CLOCK_CONTROL, 0,
 		data->model_data->scaler_bit_width, 0, &data->clk_lock);
-	if (IS_ERR(data->clk_scaler)) {
-		ret = PTR_ERR(data->clk_scaler);
-		goto scaler_error;
-	}
+	if (IS_ERR(data->clk_scaler))
+		return PTR_ERR(data->clk_scaler);
 
 	data->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
 	if (IS_ERR(data->rst)) {
 		dev_err(&pdev->dev,
 			"invalid or missing reset controller device tree entry");
-		ret = PTR_ERR(data->rst);
-		goto reset_error;
+		return PTR_ERR(data->rst);
 	}
 	reset_control_deassert(data->rst);
 
+	ret = devm_add_action_or_reset(data->dev, aspeed_adc_reset_assert,
+				       data->rst);
+	if (ret)
+		return ret;
+
 	ret = aspeed_adc_vref_config(indio_dev);
 	if (ret)
-		goto vref_config_error;
+		return ret;
 
-	if (data->model_data->wait_init_sequence) {
-		/* Enable engine in normal mode. */
-		writel(FIELD_PREP(ASPEED_ADC_OP_MODE,
-				  ASPEED_ADC_OP_MODE_NORMAL) |
-			       ASPEED_ADC_ENGINE_ENABLE,
-		       data->base + ASPEED_REG_ENGINE_CONTROL);
+	/* Enable engine in normal mode. */
+	writel(FIELD_PREP(ASPEED_ADC_OP_MODE, ASPEED_ADC_OP_MODE_NORMAL) |
+		       ASPEED_ADC_ENGINE_ENABLE,
+	       data->base + ASPEED_REG_ENGINE_CONTROL);
+
+	ret = devm_add_action_or_reset(data->dev, aspeed_adc_power_down,
+					data);
+	if (ret)
+		return ret;
 
+	if (data->model_data->wait_init_sequence) {
 		/* Wait for initial sequence complete. */
 		ret = readl_poll_timeout(data->base + ASPEED_REG_ENGINE_CONTROL,
 					 adc_engine_control_reg_val,
@@ -289,18 +317,23 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 					 ASPEED_ADC_INIT_POLLING_TIME,
 					 ASPEED_ADC_INIT_TIMEOUT);
 		if (ret)
-			goto poll_timeout_error;
+			return ret;
 	}
 
-	/* Start all channels in normal mode. */
 	ret = clk_prepare_enable(data->clk_scaler->clk);
 	if (ret)
-		goto clk_enable_error;
+		return ret;
 
+	ret = devm_add_action_or_reset(data->dev,
+				       aspeed_adc_clk_disable_unprepare,
+				       data->clk_scaler->clk);
+	if (ret)
+		return ret;
+
+	/* Start all channels in normal mode. */
 	adc_engine_control_reg_val =
-		ASPEED_ADC_CTRL_CHANNEL |
-		FIELD_PREP(ASPEED_ADC_OP_MODE, ASPEED_ADC_OP_MODE_NORMAL) |
-		ASPEED_ADC_ENGINE_ENABLE;
+		readl(data->base + ASPEED_REG_ENGINE_CONTROL);
+	adc_engine_control_reg_val |= ASPEED_ADC_CTRL_CHANNEL;
 	writel(adc_engine_control_reg_val,
 	       data->base + ASPEED_REG_ENGINE_CONTROL);
 
@@ -310,45 +343,10 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 	indio_dev->channels = aspeed_adc_iio_channels;
 	indio_dev->num_channels = data->model_data->num_channels;
 
-	ret = iio_device_register(indio_dev);
-	if (ret)
-		goto iio_register_error;
-
-	return 0;
-
-iio_register_error:
-	writel(FIELD_PREP(ASPEED_ADC_OP_MODE, ASPEED_ADC_OP_MODE_PWR_DOWN),
-	       data->base + ASPEED_REG_ENGINE_CONTROL);
-	clk_disable_unprepare(data->clk_scaler->clk);
-clk_enable_error:
-poll_timeout_error:
-vref_config_error:
-	reset_control_assert(data->rst);
-reset_error:
-	clk_hw_unregister_divider(data->clk_scaler);
-scaler_error:
-	if (data->model_data->need_prescaler)
-		clk_hw_unregister_divider(data->clk_prescaler);
+	ret = devm_iio_device_register(data->dev, indio_dev);
 	return ret;
 }
 
-static int aspeed_adc_remove(struct platform_device *pdev)
-{
-	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
-	struct aspeed_adc_data *data = iio_priv(indio_dev);
-
-	iio_device_unregister(indio_dev);
-	writel(FIELD_PREP(ASPEED_ADC_OP_MODE, ASPEED_ADC_OP_MODE_PWR_DOWN),
-	       data->base + ASPEED_REG_ENGINE_CONTROL);
-	clk_disable_unprepare(data->clk_scaler->clk);
-	reset_control_assert(data->rst);
-	clk_hw_unregister_divider(data->clk_scaler);
-	if (data->model_data->need_prescaler)
-		clk_hw_unregister_divider(data->clk_prescaler);
-
-	return 0;
-}
-
 static const struct aspeed_adc_model_data ast2400_model_data = {
 	.model_name = "ast2400-adc",
 	.vref_fixed_mv = 2500,
@@ -379,7 +377,6 @@ MODULE_DEVICE_TABLE(of, aspeed_adc_matches);
 
 static struct platform_driver aspeed_adc_driver = {
 	.probe = aspeed_adc_probe,
-	.remove = aspeed_adc_remove,
 	.driver = {
 		.name = KBUILD_MODNAME,
 		.of_match_table = aspeed_adc_matches,
-- 
2.25.1

[v7 06/11] iio: adc: aspeed: Support ast2600 adc.

[Billy Tsai]

Make driver to support ast2600 adc device.
- Use shared reset controller
- Complete the vref configure function
- Add the model data for ast2600 adc

Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
---
 drivers/iio/adc/aspeed_adc.c | 101 +++++++++++++++++++++++++++++++++--
 1 file changed, 96 insertions(+), 5 deletions(-)

diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
index 0a18893c47f0..3ec4e1a2ddd3 100644
--- a/drivers/iio/adc/aspeed_adc.c
+++ b/drivers/iio/adc/aspeed_adc.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Aspeed AST2400/2500 ADC
+ * Aspeed AST2400/2500/2600 ADC
  *
  * Copyright (C) 2017 Google, Inc.
  * Copyright (C) 2021 Aspeed Technology Inc.
@@ -14,6 +14,7 @@
 #include <linux/module.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
 #include <linux/reset.h>
 #include <linux/spinlock.h>
 #include <linux/types.h>
@@ -81,6 +82,7 @@ struct aspeed_adc_model_data {
 struct aspeed_adc_data {
 	struct device		*dev;
 	const struct aspeed_adc_model_data *model_data;
+	struct regulator	*regulator;
 	void __iomem		*base;
 	spinlock_t		clk_lock;
 	struct clk_hw		*clk_prescaler;
@@ -217,14 +219,79 @@ static void aspeed_adc_power_down(void *data)
 	       priv_data->base + ASPEED_REG_ENGINE_CONTROL);
 }
 
+static void aspeed_adc_reg_disable(void *data)
+{
+	struct regulator *reg = data;
+
+	regulator_disable(reg);
+}
+
 static int aspeed_adc_vref_config(struct iio_dev *indio_dev)
 {
 	struct aspeed_adc_data *data = iio_priv(indio_dev);
+	int ret;
+	u32 adc_engine_control_reg_val;
 
 	if (data->model_data->vref_fixed_mv) {
 		data->vref_mv = data->model_data->vref_fixed_mv;
 		return 0;
 	}
+	adc_engine_control_reg_val =
+		readl(data->base + ASPEED_REG_ENGINE_CONTROL);
+	data->regulator = devm_regulator_get_optional(data->dev, "vref");
+	if (!IS_ERR(data->regulator)) {
+		ret = regulator_enable(data->regulator);
+		if (ret)
+			return ret;
+		ret = devm_add_action_or_reset(
+			data->dev, aspeed_adc_reg_disable, data->regulator);
+		if (ret)
+			return ret;
+		data->vref_mv = regulator_get_voltage(data->regulator);
+		/* Conversion from uV to mV */
+		data->vref_mv /= 1000;
+		if ((data->vref_mv >= 1550) && (data->vref_mv <= 2700))
+			writel(adc_engine_control_reg_val |
+				FIELD_PREP(
+					ASPEED_ADC_REF_VOLTAGE,
+					ASPEED_ADC_REF_VOLTAGE_EXT_HIGH),
+			data->base + ASPEED_REG_ENGINE_CONTROL);
+		else if ((data->vref_mv >= 900) && (data->vref_mv <= 1650))
+			writel(adc_engine_control_reg_val |
+				FIELD_PREP(
+					ASPEED_ADC_REF_VOLTAGE,
+					ASPEED_ADC_REF_VOLTAGE_EXT_LOW),
+			data->base + ASPEED_REG_ENGINE_CONTROL);
+		else {
+			dev_err(data->dev, "Regulator voltage %d not support",
+				data->vref_mv);
+			return -EOPNOTSUPP;
+		}
+	} else {
+		if (PTR_ERR(data->regulator) != -ENODEV)
+			return PTR_ERR(data->regulator);
+		data->vref_mv = 2500000;
+		of_property_read_u32(data->dev->of_node,
+				     "aspeed,int-vref-microvolt",
+				     &data->vref_mv);
+		/* Conversion from uV to mV */
+		data->vref_mv /= 1000;
+		if (data->vref_mv == 2500)
+			writel(adc_engine_control_reg_val |
+				FIELD_PREP(ASPEED_ADC_REF_VOLTAGE,
+						ASPEED_ADC_REF_VOLTAGE_2500mV),
+			data->base + ASPEED_REG_ENGINE_CONTROL);
+		else if (data->vref_mv == 1200)
+			writel(adc_engine_control_reg_val |
+				FIELD_PREP(ASPEED_ADC_REF_VOLTAGE,
+						ASPEED_ADC_REF_VOLTAGE_1200mV),
+			data->base + ASPEED_REG_ENGINE_CONTROL);
+		else {
+			dev_err(data->dev, "Voltage %d not support", data->vref_mv);
+			return -EOPNOTSUPP;
+		}
+	}
+
 	return 0;
 }
 
@@ -281,7 +348,7 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 	if (IS_ERR(data->clk_scaler))
 		return PTR_ERR(data->clk_scaler);
 
-	data->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+	data->rst = devm_reset_control_get_shared(&pdev->dev, NULL);
 	if (IS_ERR(data->rst)) {
 		dev_err(&pdev->dev,
 			"invalid or missing reset controller device tree entry");
@@ -298,9 +365,13 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	adc_engine_control_reg_val =
+		readl(data->base + ASPEED_REG_ENGINE_CONTROL);
+	adc_engine_control_reg_val |=
+		FIELD_PREP(ASPEED_ADC_OP_MODE, ASPEED_ADC_OP_MODE_NORMAL) |
+		ASPEED_ADC_ENGINE_ENABLE;
 	/* Enable engine in normal mode. */
-	writel(FIELD_PREP(ASPEED_ADC_OP_MODE, ASPEED_ADC_OP_MODE_NORMAL) |
-		       ASPEED_ADC_ENGINE_ENABLE,
+	writel(adc_engine_control_reg_val,
 	       data->base + ASPEED_REG_ENGINE_CONTROL);
 
 	ret = devm_add_action_or_reset(data->dev, aspeed_adc_power_down,
@@ -368,9 +439,29 @@ static const struct aspeed_adc_model_data ast2500_model_data = {
 	.num_channels = 16,
 };
 
+static const struct aspeed_adc_model_data ast2600_adc0_model_data = {
+	.model_name = "ast2600-adc0",
+	.min_sampling_rate = 10000,
+	.max_sampling_rate = 500000,
+	.wait_init_sequence = true,
+	.scaler_bit_width = 16,
+	.num_channels = 8,
+};
+
+static const struct aspeed_adc_model_data ast2600_adc1_model_data = {
+	.model_name = "ast2600-adc1",
+	.min_sampling_rate = 10000,
+	.max_sampling_rate = 500000,
+	.wait_init_sequence = true,
+	.scaler_bit_width = 16,
+	.num_channels = 8,
+};
+
 static const struct of_device_id aspeed_adc_matches[] = {
 	{ .compatible = "aspeed,ast2400-adc", .data = &ast2400_model_data },
 	{ .compatible = "aspeed,ast2500-adc", .data = &ast2500_model_data },
+	{ .compatible = "aspeed,ast2600-adc0", .data = &ast2600_adc0_model_data },
+	{ .compatible = "aspeed,ast2600-adc1", .data = &ast2600_adc1_model_data },
 	{},
 };
 MODULE_DEVICE_TABLE(of, aspeed_adc_matches);
@@ -386,5 +477,5 @@ static struct platform_driver aspeed_adc_driver = {
 module_platform_driver(aspeed_adc_driver);
 
 MODULE_AUTHOR("Rick Altherr <raltherr@google.com>");
-MODULE_DESCRIPTION("Aspeed AST2400/2500 ADC Driver");
+MODULE_DESCRIPTION("Aspeed AST2400/2500/2600 ADC Driver");
 MODULE_LICENSE("GPL");
-- 
2.25.1

[v7 07/11] iio: adc: aspeed: Fix the calculate error of clock.

[Billy Tsai]

The ADC clock formula is
ast2400/2500:
ADC clock period = PCLK * 2 * (ADC0C[31:17] + 1) * (ADC0C[9:0] + 1)
ast2600:
ADC clock period = PCLK * 2 * (ADC0C[15:0] + 1)
They all have one fixed divided 2 and the legacy driver didn't handle it.
This patch register the fixed factory clock device as the parent of ADC
clock scaler to fix this issue.

Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
---
 drivers/iio/adc/aspeed_adc.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
index 3ec4e1a2ddd3..a24be2a4f69c 100644
--- a/drivers/iio/adc/aspeed_adc.c
+++ b/drivers/iio/adc/aspeed_adc.c
@@ -4,6 +4,12 @@
  *
  * Copyright (C) 2017 Google, Inc.
  * Copyright (C) 2021 Aspeed Technology Inc.
+ *
+ * ADC clock formula:
+ * Ast2400/Ast2500:
+ * clock period = period of PCLK * 2 * (ADC0C[31:17] + 1) * (ADC0C[9:0] + 1)
+ * Ast2600:
+ * clock period = period of PCLK * 2 * (ADC0C[15:0] + 1)
  */
 
 #include <linux/clk.h>
@@ -85,6 +91,7 @@ struct aspeed_adc_data {
 	struct regulator	*regulator;
 	void __iomem		*base;
 	spinlock_t		clk_lock;
+	struct clk_hw		*fixed_div_clk;
 	struct clk_hw		*clk_prescaler;
 	struct clk_hw		*clk_scaler;
 	struct reset_control	*rst;
@@ -197,6 +204,13 @@ static const struct iio_info aspeed_adc_iio_info = {
 	.debugfs_reg_access = aspeed_adc_reg_access,
 };
 
+static void aspeed_adc_unregister_fixed_divider(void *data)
+{
+	struct clk_hw *clk = data;
+
+	clk_hw_unregister_fixed_factor(clk);
+}
+
 static void aspeed_adc_reset_assert(void *data)
 {
 	struct reset_control *rst = data;
@@ -321,6 +335,19 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 	spin_lock_init(&data->clk_lock);
 	snprintf(clk_parent_name, ARRAY_SIZE(clk_parent_name), "%s",
 		 of_clk_get_parent_name(pdev->dev.of_node, 0));
+	snprintf(clk_name, ARRAY_SIZE(clk_name), "%s-fixed-div",
+		 data->model_data->model_name);
+	data->fixed_div_clk = clk_hw_register_fixed_factor(
+		&pdev->dev, clk_name, clk_parent_name, 0, 1, 2);
+	if (IS_ERR(data->fixed_div_clk))
+		return PTR_ERR(data->fixed_div_clk);
+
+	ret = devm_add_action_or_reset(data->dev,
+				       aspeed_adc_unregister_fixed_divider,
+				       data->fixed_div_clk);
+	if (ret)
+		return ret;
+	snprintf(clk_parent_name, ARRAY_SIZE(clk_parent_name), clk_name);
 
 	if (data->model_data->need_prescaler) {
 		snprintf(clk_name, ARRAY_SIZE(clk_name), "%s-prescaler",
-- 
2.25.1

[v7 08/11] iio: adc: aspeed: Add func to set sampling rate.

[Billy Tsai]

Add the function to set the sampling rate and keep the sampling period
for a driver used to wait the fresh value.
In addition, since the ADC clock is required when initializing the ADC
device, move clk_prepare_enable ahead of the initialization phase.

Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
---
 drivers/iio/adc/aspeed_adc.c | 58 ++++++++++++++++++++++++------------
 1 file changed, 39 insertions(+), 19 deletions(-)

diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
index a24be2a4f69c..f2226ba3144d 100644
--- a/drivers/iio/adc/aspeed_adc.c
+++ b/drivers/iio/adc/aspeed_adc.c
@@ -73,6 +73,12 @@
 
 #define ASPEED_ADC_INIT_POLLING_TIME	500
 #define ASPEED_ADC_INIT_TIMEOUT		500000
+/*
+ * When the sampling rate is too high, the ADC may not have enough charging
+ * time, resulting in a low voltage value. Thus, the default uses a slow
+ * sampling rate for most use cases.
+ */
+#define ASPEED_ADC_DEF_SAMPLING_RATE	65000
 
 struct aspeed_adc_model_data {
 	const char *model_name;
@@ -96,6 +102,7 @@ struct aspeed_adc_data {
 	struct clk_hw		*clk_scaler;
 	struct reset_control	*rst;
 	int			vref_mv;
+	u32			sample_period_ns;
 };
 
 #define ASPEED_CHAN(_idx, _data_reg_addr) {			\
@@ -127,6 +134,24 @@ static const struct iio_chan_spec aspeed_adc_iio_channels[] = {
 	ASPEED_CHAN(15, 0x2E),
 };
 
+static int aspeed_adc_set_sampling_rate(struct iio_dev *indio_dev, u32 rate)
+{
+	struct aspeed_adc_data *data = iio_priv(indio_dev);
+
+	if (rate < data->model_data->min_sampling_rate ||
+	    rate > data->model_data->max_sampling_rate)
+		return -EINVAL;
+	/* Each sampling needs 12 clocks to convert.*/
+	clk_set_rate(data->clk_scaler->clk, rate * ASPEED_CLOCKS_PER_SAMPLE);
+	rate = clk_get_rate(data->clk_scaler->clk);
+	data->sample_period_ns = DIV_ROUND_UP_ULL(
+		(u64)NSEC_PER_SEC * ASPEED_CLOCKS_PER_SAMPLE, rate);
+	dev_dbg(data->dev, "Adc clock = %d sample period = %d ns", rate,
+		data->sample_period_ns);
+
+	return 0;
+}
+
 static int aspeed_adc_read_raw(struct iio_dev *indio_dev,
 			       struct iio_chan_spec const *chan,
 			       int *val, int *val2, long mask)
@@ -157,17 +182,9 @@ static int aspeed_adc_write_raw(struct iio_dev *indio_dev,
 				struct iio_chan_spec const *chan,
 				int val, int val2, long mask)
 {
-	struct aspeed_adc_data *data = iio_priv(indio_dev);
-
 	switch (mask) {
 	case IIO_CHAN_INFO_SAMP_FREQ:
-		if (val < data->model_data->min_sampling_rate ||
-			val > data->model_data->max_sampling_rate)
-			return -EINVAL;
-
-		clk_set_rate(data->clk_scaler->clk,
-				val * ASPEED_CLOCKS_PER_SAMPLE);
-		return 0;
+		return aspeed_adc_set_sampling_rate(indio_dev, val);
 
 	case IIO_CHAN_INFO_SCALE:
 	case IIO_CHAN_INFO_RAW:
@@ -392,6 +409,19 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	ret = clk_prepare_enable(data->clk_scaler->clk);
+	if (ret)
+		return ret;
+	ret = devm_add_action_or_reset(data->dev,
+				       aspeed_adc_clk_disable_unprepare,
+				       data->clk_scaler->clk);
+	if (ret)
+		return ret;
+	ret = aspeed_adc_set_sampling_rate(indio_dev,
+					   ASPEED_ADC_DEF_SAMPLING_RATE);
+	if (ret)
+		return ret;
+
 	adc_engine_control_reg_val =
 		readl(data->base + ASPEED_REG_ENGINE_CONTROL);
 	adc_engine_control_reg_val |=
@@ -418,16 +448,6 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 			return ret;
 	}
 
-	ret = clk_prepare_enable(data->clk_scaler->clk);
-	if (ret)
-		return ret;
-
-	ret = devm_add_action_or_reset(data->dev,
-				       aspeed_adc_clk_disable_unprepare,
-				       data->clk_scaler->clk);
-	if (ret)
-		return ret;
-
 	/* Start all channels in normal mode. */
 	adc_engine_control_reg_val =
 		readl(data->base + ASPEED_REG_ENGINE_CONTROL);
-- 
2.25.1

[v7 09/11] iio: adc: aspeed: Add compensation phase.

[Billy Tsai]

This patch adds a compensation phase to improve the accuracy of ADC
measurement. This is the built-in function through input half of the
reference voltage to get the ADC offset.

Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
---
 drivers/iio/adc/aspeed_adc.c | 54 +++++++++++++++++++++++++++++++++++-
 1 file changed, 53 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
index f2226ba3144d..efda76fa0aa1 100644
--- a/drivers/iio/adc/aspeed_adc.c
+++ b/drivers/iio/adc/aspeed_adc.c
@@ -103,6 +103,7 @@ struct aspeed_adc_data {
 	struct reset_control	*rst;
 	int			vref_mv;
 	u32			sample_period_ns;
+	int			cv;
 };
 
 #define ASPEED_CHAN(_idx, _data_reg_addr) {			\
@@ -112,7 +113,8 @@ struct aspeed_adc_data {
 	.address = (_data_reg_addr),				\
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |	\
-				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
+				BIT(IIO_CHAN_INFO_SAMP_FREQ) |	\
+				BIT(IIO_CHAN_INFO_OFFSET),	\
 }
 
 static const struct iio_chan_spec aspeed_adc_iio_channels[] = {
@@ -134,6 +136,51 @@ static const struct iio_chan_spec aspeed_adc_iio_channels[] = {
 	ASPEED_CHAN(15, 0x2E),
 };
 
+static int aspeed_adc_compensation(struct iio_dev *indio_dev)
+{
+	struct aspeed_adc_data *data = iio_priv(indio_dev);
+	u32 index, adc_raw = 0;
+	u32 adc_engine_control_reg_val;
+
+	adc_engine_control_reg_val =
+		readl(data->base + ASPEED_REG_ENGINE_CONTROL);
+	adc_engine_control_reg_val &= ~ASPEED_ADC_OP_MODE;
+	adc_engine_control_reg_val |=
+		(FIELD_PREP(ASPEED_ADC_OP_MODE, ASPEED_ADC_OP_MODE_NORMAL) |
+		 ASPEED_ADC_ENGINE_ENABLE);
+	/*
+	 * Enable compensating sensing:
+	 * After that, the input voltage of ADC will force to half of the reference
+	 * voltage. So the expected reading raw data will become half of the max
+	 * value. We can get compensating value = 0x200 - ADC read raw value.
+	 * It is recommended to average at least 10 samples to get a final CV.
+	 */
+	writel(adc_engine_control_reg_val | ASPEED_ADC_CTRL_COMPENSATION |
+		       ASPEED_ADC_CTRL_CHANNEL_ENABLE(0),
+	       data->base + ASPEED_REG_ENGINE_CONTROL);
+	/*
+	 * After enable compensating sensing mode need to wait some time for ADC stable
+	 * Experiment result is 1ms.
+	 */
+	mdelay(1);
+
+	for (index = 0; index < 16; index++) {
+		/*
+		 * Waiting for the sampling period ensures that the value acquired
+		 * is fresh each time.
+		 */
+		ndelay(data->sample_period_ns);
+		adc_raw += readw(data->base + aspeed_adc_iio_channels[0].address);
+	}
+	adc_raw >>= 4;
+	data->cv = BIT(ASPEED_RESOLUTION_BITS - 1) - adc_raw;
+	writel(adc_engine_control_reg_val,
+	       data->base + ASPEED_REG_ENGINE_CONTROL);
+	dev_dbg(data->dev, "Compensating value = %d\n", data->cv);
+
+	return 0;
+}
+
 static int aspeed_adc_set_sampling_rate(struct iio_dev *indio_dev, u32 rate)
 {
 	struct aspeed_adc_data *data = iio_priv(indio_dev);
@@ -163,6 +210,10 @@ static int aspeed_adc_read_raw(struct iio_dev *indio_dev,
 		*val = readw(data->base + chan->address);
 		return IIO_VAL_INT;
 
+	case IIO_CHAN_INFO_OFFSET:
+		*val = data->cv;
+		return IIO_VAL_INT;
+
 	case IIO_CHAN_INFO_SCALE:
 		*val = data->vref_mv;
 		*val2 = ASPEED_RESOLUTION_BITS;
@@ -448,6 +499,7 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 			return ret;
 	}
 
+	aspeed_adc_compensation(indio_dev);
 	/* Start all channels in normal mode. */
 	adc_engine_control_reg_val =
 		readl(data->base + ASPEED_REG_ENGINE_CONTROL);
-- 
2.25.1

[v7 10/11] iio: adc: aspeed: Support battery sensing.

[Billy Tsai]

In ast2600, ADC integrate dividing circuit at last input channel for
battery sensing. This patch use the dts property "battery-sensing" to
enable this feature makes the last channel of each adc can tolerance
higher voltage than reference voltage. The offset interface of ch7 will
be separated when enabling the battery sensing mode.

Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
---
 drivers/iio/adc/aspeed_adc.c | 81 ++++++++++++++++++++++++++++++++++--
 1 file changed, 78 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
index efda76fa0aa1..e22c59f6c3d0 100644
--- a/drivers/iio/adc/aspeed_adc.c
+++ b/drivers/iio/adc/aspeed_adc.c
@@ -87,10 +87,16 @@ struct aspeed_adc_model_data {
 	unsigned int vref_fixed_mv;
 	bool wait_init_sequence;
 	bool need_prescaler;
+	bool bat_sense_sup;
 	u8 scaler_bit_width;
 	unsigned int num_channels;
 };
 
+struct adc_gain {
+	u8 mult;
+	u8 div;
+};
+
 struct aspeed_adc_data {
 	struct device		*dev;
 	const struct aspeed_adc_model_data *model_data;
@@ -104,6 +110,8 @@ struct aspeed_adc_data {
 	int			vref_mv;
 	u32			sample_period_ns;
 	int			cv;
+	bool			battery_sensing;
+	struct adc_gain		battery_mode_gain;
 };
 
 #define ASPEED_CHAN(_idx, _data_reg_addr) {			\
@@ -136,6 +144,27 @@ static const struct iio_chan_spec aspeed_adc_iio_channels[] = {
 	ASPEED_CHAN(15, 0x2E),
 };
 
+#define ASPEED_BAT_CHAN(_idx, _data_reg_addr) {					\
+		.type = IIO_VOLTAGE,						\
+		.indexed = 1,							\
+		.channel = (_idx),						\
+		.address = (_data_reg_addr),					\
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
+				      BIT(IIO_CHAN_INFO_OFFSET),		\
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |		\
+					    BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
+}
+static const struct iio_chan_spec aspeed_adc_iio_bat_channels[] = {
+	ASPEED_CHAN(0, 0x10),
+	ASPEED_CHAN(1, 0x12),
+	ASPEED_CHAN(2, 0x14),
+	ASPEED_CHAN(3, 0x16),
+	ASPEED_CHAN(4, 0x18),
+	ASPEED_CHAN(5, 0x1A),
+	ASPEED_CHAN(6, 0x1C),
+	ASPEED_BAT_CHAN(7, 0x1E),
+};
+
 static int aspeed_adc_compensation(struct iio_dev *indio_dev)
 {
 	struct aspeed_adc_data *data = iio_priv(indio_dev);
@@ -204,14 +233,39 @@ static int aspeed_adc_read_raw(struct iio_dev *indio_dev,
 			       int *val, int *val2, long mask)
 {
 	struct aspeed_adc_data *data = iio_priv(indio_dev);
+	u32 adc_engine_control_reg_val;
 
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
-		*val = readw(data->base + chan->address);
+		if (data->battery_sensing && chan->channel == 7) {
+			adc_engine_control_reg_val =
+				readl(data->base + ASPEED_REG_ENGINE_CONTROL);
+			writel(adc_engine_control_reg_val |
+				       FIELD_PREP(ASPEED_ADC_CH7_MODE,
+						  ASPEED_ADC_CH7_BAT) |
+				       ASPEED_ADC_BAT_SENSING_ENABLE,
+			       data->base + ASPEED_REG_ENGINE_CONTROL);
+			/*
+			 * After enable battery sensing mode need to wait some time for adc stable
+			 * Experiment result is 1ms.
+			 */
+			mdelay(1);
+			*val = readw(data->base + chan->address);
+			*val = (*val * data->battery_mode_gain.mult) /
+			       data->battery_mode_gain.div;
+			/* Restore control register value */
+			writel(adc_engine_control_reg_val,
+			       data->base + ASPEED_REG_ENGINE_CONTROL);
+		} else
+			*val = readw(data->base + chan->address);
 		return IIO_VAL_INT;
 
 	case IIO_CHAN_INFO_OFFSET:
-		*val = data->cv;
+		if (data->battery_sensing && chan->channel == 7)
+			*val = (data->cv * data->battery_mode_gain.mult) /
+			       data->battery_mode_gain.div;
+		else
+			*val = data->cv;
 		return IIO_VAL_INT;
 
 	case IIO_CHAN_INFO_SCALE:
@@ -460,6 +514,23 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	if (of_find_property(data->dev->of_node, "aspeed,battery-sensing",
+			     NULL)) {
+		if (data->model_data->bat_sense_sup) {
+			data->battery_sensing = 1;
+			if (readl(data->base + ASPEED_REG_ENGINE_CONTROL) &
+			    ASPEED_ADC_BAT_SENSING_DIV) {
+				data->battery_mode_gain.mult = 3;
+				data->battery_mode_gain.div = 1;
+			} else {
+				data->battery_mode_gain.mult = 3;
+				data->battery_mode_gain.div = 2;
+			}
+		} else
+			dev_warn(&pdev->dev,
+				 "Failed to enable battey-sensing mode\n");
+	}
+
 	ret = clk_prepare_enable(data->clk_scaler->clk);
 	if (ret)
 		return ret;
@@ -510,7 +581,9 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 	indio_dev->name = data->model_data->model_name;
 	indio_dev->info = &aspeed_adc_iio_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
-	indio_dev->channels = aspeed_adc_iio_channels;
+	indio_dev->channels = data->battery_sensing ?
+					    aspeed_adc_iio_bat_channels :
+					    aspeed_adc_iio_channels;
 	indio_dev->num_channels = data->model_data->num_channels;
 
 	ret = devm_iio_device_register(data->dev, indio_dev);
@@ -543,6 +616,7 @@ static const struct aspeed_adc_model_data ast2600_adc0_model_data = {
 	.min_sampling_rate = 10000,
 	.max_sampling_rate = 500000,
 	.wait_init_sequence = true,
+	.bat_sense_sup = true,
 	.scaler_bit_width = 16,
 	.num_channels = 8,
 };
@@ -552,6 +626,7 @@ static const struct aspeed_adc_model_data ast2600_adc1_model_data = {
 	.min_sampling_rate = 10000,
 	.max_sampling_rate = 500000,
 	.wait_init_sequence = true,
+	.bat_sense_sup = true,
 	.scaler_bit_width = 16,
 	.num_channels = 8,
 };
-- 
2.25.1

[v7 11/11] iio: adc: aspeed: Get and set trimming data.

[Billy Tsai]

The ADC controller has a trimming register for fine-tune the reference
voltage. The trimming value comes from the OTP register which will be
written during chip production. This patch will read this OTP value and
configure it to the ADC register when the ADC controller probes and using
dts property "aspeed,trim-data-valid" to determine whether to execute this
flow.

Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
---
 drivers/iio/adc/aspeed_adc.c | 71 ++++++++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)

diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
index e22c59f6c3d0..c7e15c0c1951 100644
--- a/drivers/iio/adc/aspeed_adc.c
+++ b/drivers/iio/adc/aspeed_adc.c
@@ -25,6 +25,8 @@
 #include <linux/spinlock.h>
 #include <linux/types.h>
 #include <linux/bitfield.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/driver.h>
@@ -80,6 +82,11 @@
  */
 #define ASPEED_ADC_DEF_SAMPLING_RATE	65000
 
+struct aspeed_adc_trim_locate {
+	const unsigned int offset;
+	const unsigned int field;
+};
+
 struct aspeed_adc_model_data {
 	const char *model_name;
 	unsigned int min_sampling_rate;	// Hz
@@ -90,6 +97,7 @@ struct aspeed_adc_model_data {
 	bool bat_sense_sup;
 	u8 scaler_bit_width;
 	unsigned int num_channels;
+	const struct aspeed_adc_trim_locate *trim_locate;
 };
 
 struct adc_gain {
@@ -165,6 +173,44 @@ static const struct iio_chan_spec aspeed_adc_iio_bat_channels[] = {
 	ASPEED_BAT_CHAN(7, 0x1E),
 };
 
+static int aspeed_adc_set_trim_data(struct iio_dev *indio_dev)
+{
+	struct device_node *syscon;
+	struct regmap *scu;
+	u32 scu_otp, trimming_val;
+	struct aspeed_adc_data *data = iio_priv(indio_dev);
+
+	syscon = of_find_node_by_name(NULL, "syscon");
+	if (syscon == NULL) {
+		dev_warn(data->dev, "Couldn't find syscon node\n");
+		return -EOPNOTSUPP;
+	}
+	scu = syscon_node_to_regmap(syscon);
+	if (IS_ERR(scu)) {
+		dev_warn(data->dev, "Failed to get syscon regmap\n");
+		return -EOPNOTSUPP;
+	}
+	if (data->model_data->trim_locate) {
+		if (regmap_read(scu, data->model_data->trim_locate->offset,
+				&scu_otp)) {
+			dev_warn(data->dev,
+				 "Failed to get adc trimming data\n");
+			trimming_val = 0x8;
+		} else {
+			trimming_val =
+				((scu_otp) &
+				 (data->model_data->trim_locate->field)) >>
+				__ffs(data->model_data->trim_locate->field);
+		}
+		dev_dbg(data->dev,
+			"trimming val = %d, offset = %08x, fields = %08x\n",
+			trimming_val, data->model_data->trim_locate->offset,
+			data->model_data->trim_locate->field);
+		writel(trimming_val, data->base + ASPEED_REG_COMPENSATION_TRIM);
+	}
+	return 0;
+}
+
 static int aspeed_adc_compensation(struct iio_dev *indio_dev)
 {
 	struct aspeed_adc_data *data = iio_priv(indio_dev);
@@ -514,6 +560,13 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	if (of_find_property(data->dev->of_node, "aspeed,trim-data-valid",
+			     NULL)) {
+		ret = aspeed_adc_set_trim_data(indio_dev);
+		if (ret)
+			return ret;
+	}
+
 	if (of_find_property(data->dev->of_node, "aspeed,battery-sensing",
 			     NULL)) {
 		if (data->model_data->bat_sense_sup) {
@@ -590,6 +643,21 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 	return ret;
 }
 
+static const struct aspeed_adc_trim_locate ast2500_adc_trim = {
+	.offset = 0x154,
+	.field = GENMASK(31, 28),
+};
+
+static const struct aspeed_adc_trim_locate ast2600_adc0_trim = {
+	.offset = 0x5d0,
+	.field = GENMASK(3, 0),
+};
+
+static const struct aspeed_adc_trim_locate ast2600_adc1_trim = {
+	.offset = 0x5d0,
+	.field = GENMASK(7, 4),
+};
+
 static const struct aspeed_adc_model_data ast2400_model_data = {
 	.model_name = "ast2400-adc",
 	.vref_fixed_mv = 2500,
@@ -609,6 +677,7 @@ static const struct aspeed_adc_model_data ast2500_model_data = {
 	.need_prescaler = true,
 	.scaler_bit_width = 10,
 	.num_channels = 16,
+	.trim_locate = &ast2500_adc_trim,
 };
 
 static const struct aspeed_adc_model_data ast2600_adc0_model_data = {
@@ -619,6 +688,7 @@ static const struct aspeed_adc_model_data ast2600_adc0_model_data = {
 	.bat_sense_sup = true,
 	.scaler_bit_width = 16,
 	.num_channels = 8,
+	.trim_locate = &ast2600_adc0_trim,
 };
 
 static const struct aspeed_adc_model_data ast2600_adc1_model_data = {
@@ -629,6 +699,7 @@ static const struct aspeed_adc_model_data ast2600_adc1_model_data = {
 	.bat_sense_sup = true,
 	.scaler_bit_width = 16,
 	.num_channels = 8,
+	.trim_locate = &ast2600_adc1_trim,
 };
 
 static const struct of_device_id aspeed_adc_matches[] = {
-- 
2.25.1

Re: [v7 00/11] Add support for ast2600 ADC

[Jonathan Cameron]

On Wed, 22 Sep 2021 16:15:09 +0800
Billy Tsai <billy_tsai@aspeedtech.com> wrote:

> This patch serials make aspeed_adc.c can support ast2600 and backward
> compatible.

Hi Billy,

Series applied to the togreg branch of iio.git and pushed out as testing for
0-day to poke at it.

Note the fix for platform_set_drvdata() is in the fixes branch so there will
be a bit of mess around context for patch 1 but that should all resolve in
a trivial fashion.

Thanks,

Jonathan

> 
> Change since v6:
> aspeed_adc.c:
>  - Fix the parameter error for aspeed_adc_unregister_fixed_divider.
> 
> Change since v5:
> aspeed_adc.c:
>   - Use devm_clk_hw_register_divider()
>   - Enabling and setting the ADC to normal mode is a necessary flow, so
>   take it out of the condition.
> 
> Change since v4:
> dt-bindings:
>   - Add clocks maxItems.
>   - Rename the property to meet the property-units.yaml.
>   - Add the description for the difference between adc0 and adc1.
> aspeed_adc.c:
>   - Use new property name to get internal reference voltage: units from mv
>   to uv.
>   - Fix -Wnonnull warning caused by snprintf parameters.
>   - Add suffix mv to the vref parameters.
>   - Use ARRAY_SIZE instead of 32.
>   - Add a reset action for ADC power down and Use devm_iio_device_register.
>   - Fix typo error.
>   - Separate the offset interface of ch7 when battery sensing enable
> 
> Change since v3:
> dt-bindings:
>   - Fix properties:aspeed,int_vref_mv type error.
> 
> Change since v2:
> dt-bindings:
>   - Create a new dt-bindings for ast2600 adc
> aspeed_adc.c:
>   - Splits the patch for more details
>   - Remove version enum and use the flags in model data to distinguish
>   hardware feature
>   - Support trimming data get and set.
>   - Use devm_add_action_or_reset to simplify probe error handling.
> 
> Changes since v1:
> dt-bindings:
>   - Fix the aspeed,adc.yaml check error.
>   - Add battery-sensing property.
> aspeed_adc.c:
>   - Change the init flow:
>     Clock and reference voltage setting should be completed before adc
>     engine enable.
>   - Change the default sampling rate to meet most user case.
>   - Add patch #8 to suppoert battery sensing mode.
> 
> Billy Tsai (11):
>   iio: adc: aspeed: Keep model data to driver data.
>   iio: adc: aspeed: Restructure the model data
>   iio: adc: aspeed: Add vref config function
>   iio: adc: aspeed: Use model_data to set clk scaler.
>   iio: adc: aspeed: Use devm_add_action_or_reset.
>   iio: adc: aspeed: Support ast2600 adc.
>   iio: adc: aspeed: Fix the calculate error of clock.
>   iio: adc: aspeed: Add func to set sampling rate.
>   iio: adc: aspeed: Add compensation phase.
>   iio: adc: aspeed: Support battery sensing.
>   iio: adc: aspeed: Get and set trimming data.
> 
>  drivers/iio/adc/aspeed_adc.c | 554 +++++++++++++++++++++++++++++------
>  1 file changed, 459 insertions(+), 95 deletions(-)
>