[v3 00/15] Add support for ast2600 ADC

[v3 00/15] Add support for ast2600 ADC

[Billy Tsai]

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

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 (15):
  dt-bindings: iio: adc: Add ast2600-adc bindings
  iio: adc: aspeed: completes the bitfield declare.
  iio: adc: aspeed: set driver data when adc probe.
  iio: adc: aspeed: Keep model data to driver data.
  iio: adc: aspeed: Refactory model data structure
  iio: adc: aspeed: Add vref config function
  iio: adc: aspeed: Set num_channels with model data
  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.

 .../bindings/iio/adc/aspeed,ast2600-adc.yaml  |  98 +++
 drivers/iio/adc/aspeed_adc.c                  | 562 +++++++++++++++---
 2 files changed, 570 insertions(+), 90 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/aspeed,ast2600-adc.yaml

-- 
2.25.1

[v3 01/15] dt-bindings: iio: adc: Add ast2600-adc bindings

[Billy Tsai]

Add device tree bindings document for the aspeed ast2600 adc device
driver.

Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
---
 .../bindings/iio/adc/aspeed,ast2600-adc.yaml  | 98 +++++++++++++++++++
 1 file changed, 98 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/aspeed,ast2600-adc.yaml

diff --git a/Documentation/devicetree/bindings/iio/adc/aspeed,ast2600-adc.yaml b/Documentation/devicetree/bindings/iio/adc/aspeed,ast2600-adc.yaml
new file mode 100644
index 000000000000..28bff89e0d75
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/aspeed,ast2600-adc.yaml
@@ -0,0 +1,98 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/aspeed,ast2600-adc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ADC that forms part of an ASPEED server management processor.
+
+maintainers:
+  - Billy Tsai <billy_tsai@aspeedtech.com>
+
+description: |
+  • 10-bits resolution for 16 voltage channels.
+  • The device split into two individual engine and each contains 8 voltage
+  channels.
+  • Channel scanning can be non-continuous.
+  • Programmable ADC clock frequency.
+  • Programmable upper and lower threshold for each channels.
+  • Interrupt when larger or less than threshold for each channels.
+  • Support hysteresis for each channels.
+  • Built-in a compensating method.
+  • Built-in a register to trim internal reference voltage.
+  • Internal or External reference voltage.
+  • Support 2 Internal reference voltage 1.2v or 2.5v.
+  • Integrate dividing circuit for battery sensing.
+
+properties:
+  compatible:
+    enum:
+      - aspeed,ast2600-adc0
+      - aspeed,ast2600-adc1
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    description:
+      Input clock used to derive the sample clock. Expected to be the
+      SoC's APB clock.
+
+  resets:
+    maxItems: 1
+
+  "#io-channel-cells":
+    const: 1
+
+  vref-supply:
+    description:
+      The external regulator supply ADC reference voltage.
+
+  aspeed,int_vref_mv:
+    enum:
+      - 1200
+      - 2500
+    description:
+      ADC internal reference voltage in millivolts.
+
+  aspeed,battery-sensing:
+    type: boolean
+    description:
+      Inform the driver that last channel will be used to sensor battery.
+
+  aspeed,trim-data-valid:
+    type: boolean
+    description: |
+      The ADC reference voltage can be calibrated to obtain the trimming
+      data which will be stored in otp. This property informs the driver that
+      the data store in the otp is valid.
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - resets
+  - "#io-channel-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/ast2600-clock.h>
+    adc0: adc@1e6e9000 {
+        compatible = "aspeed,ast2600-adc0";
+        reg = <0x1e6e9000 0x100>;
+        clocks = <&syscon ASPEED_CLK_APB2>;
+        resets = <&syscon ASPEED_RESET_ADC>;
+        #io-channel-cells = <1>;
+        aspeed,int_vref_mv = <2500>;
+    };
+    adc1: adc@1e6e9100 {
+        compatible = "aspeed,ast2600-adc1";
+        reg = <0x1e6e9100 0x100>;
+        clocks = <&syscon ASPEED_CLK_APB2>;
+        resets = <&syscon ASPEED_RESET_ADC>;
+        #io-channel-cells = <1>;
+        aspeed,int_vref_mv = <2500>;
+    };
+...
-- 
2.25.1

[v3 02/15] iio: adc: aspeed: completes the bitfield declare.

[Billy Tsai]

This patch completes the declare of adc register bitfields and uses the
same prefix ASPEED_ADC_* for these bitfields.

Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
---
 drivers/iio/adc/aspeed_adc.c | 56 +++++++++++++++++++++++++-----------
 1 file changed, 39 insertions(+), 17 deletions(-)

diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
index 19efaa41bc34..7010d56ac3b9 100644
--- a/drivers/iio/adc/aspeed_adc.c
+++ b/drivers/iio/adc/aspeed_adc.c
@@ -3,6 +3,7 @@
  * Aspeed AST2400/2500 ADC
  *
  * Copyright (C) 2017 Google, Inc.
+ * Copyright (C) 2021 Aspeed Technology Inc.
  */
 
 #include <linux/clk.h>
@@ -16,6 +17,7 @@
 #include <linux/reset.h>
 #include <linux/spinlock.h>
 #include <linux/types.h>
+#include <linux/bitfield.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/driver.h>
@@ -28,15 +30,31 @@
 #define ASPEED_REG_INTERRUPT_CONTROL	0x04
 #define ASPEED_REG_VGA_DETECT_CONTROL	0x08
 #define ASPEED_REG_CLOCK_CONTROL	0x0C
-#define ASPEED_REG_MAX			0xC0
-
-#define ASPEED_OPERATION_MODE_POWER_DOWN	(0x0 << 1)
-#define ASPEED_OPERATION_MODE_STANDBY		(0x1 << 1)
-#define ASPEED_OPERATION_MODE_NORMAL		(0x7 << 1)
-
-#define ASPEED_ENGINE_ENABLE		BIT(0)
-
-#define ASPEED_ADC_CTRL_INIT_RDY	BIT(8)
+#define ASPEED_REG_COMPENSATION_TRIM	0xC4
+#define ASPEED_REG_MAX			0xCC
+
+#define ASPEED_ADC_ENGINE_ENABLE		BIT(0)
+#define ASPEED_ADC_OP_MODE			GENMASK(3, 1)
+#define ASPEED_ADC_OP_MODE_PWR_DOWN		0
+#define ASPEED_ADC_OP_MODE_STANDBY		1
+#define ASPEED_ADC_OP_MODE_NORMAL		7
+#define ASPEED_ADC_CTRL_COMPENSATION		BIT(4)
+#define ASPEED_ADC_AUTO_COMPENSATION		BIT(5)
+#define ASPEED_ADC_REF_VOLTAGE			GENMASK(7, 6)
+#define ASPEED_ADC_REF_VOLTAGE_2500mV		0
+#define ASPEED_ADC_REF_VOLTAGE_1200mV		1
+#define ASPEED_ADC_REF_VOLTAGE_EXT_HIGH		2
+#define ASPEED_ADC_REF_VOLTAGE_EXT_LOW		3
+#define ASPEED_ADC_BAT_SENSING_DIV		BIT(6)
+#define ASPEED_ADC_BAT_SENSING_DIV_2_3		0
+#define ASPEED_ADC_BAT_SENSING_DIV_1_3		1
+#define ASPEED_ADC_CTRL_INIT_RDY		BIT(8)
+#define ASPEED_ADC_CH7_MODE			BIT(12)
+#define ASPEED_ADC_CH7_NORMAL			0
+#define ASPEED_ADC_CH7_BAT			1
+#define ASPEED_ADC_BAT_SENSING_ENABLE		BIT(13)
+#define ASPEED_ADC_CTRL_CHANNEL			GENMASK(31, 16)
+#define ASPEED_ADC_CTRL_CHANNEL_ENABLE(ch)	FIELD_PREP(ASPEED_ADC_CTRL_CHANNEL, BIT(ch))
 
 #define ASPEED_ADC_INIT_POLLING_TIME	500
 #define ASPEED_ADC_INIT_TIMEOUT		500000
@@ -226,7 +244,9 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 
 	if (model_data->wait_init_sequence) {
 		/* Enable engine in normal mode. */
-		writel(ASPEED_OPERATION_MODE_NORMAL | ASPEED_ENGINE_ENABLE,
+		writel(FIELD_PREP(ASPEED_ADC_OP_MODE,
+				  ASPEED_ADC_OP_MODE_NORMAL) |
+			       ASPEED_ADC_ENGINE_ENABLE,
 		       data->base + ASPEED_REG_ENGINE_CONTROL);
 
 		/* Wait for initial sequence complete. */
@@ -245,10 +265,12 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 	if (ret)
 		goto clk_enable_error;
 
-	adc_engine_control_reg_val = GENMASK(31, 16) |
-		ASPEED_OPERATION_MODE_NORMAL | ASPEED_ENGINE_ENABLE;
+	adc_engine_control_reg_val =
+		ASPEED_ADC_CTRL_CHANNEL |
+		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);
+	       data->base + ASPEED_REG_ENGINE_CONTROL);
 
 	model_data = of_device_get_match_data(&pdev->dev);
 	indio_dev->name = model_data->model_name;
@@ -264,8 +286,8 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 	return 0;
 
 iio_register_error:
-	writel(ASPEED_OPERATION_MODE_POWER_DOWN,
-		data->base + ASPEED_REG_ENGINE_CONTROL);
+	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:
@@ -283,8 +305,8 @@ static int aspeed_adc_remove(struct platform_device *pdev)
 	struct aspeed_adc_data *data = iio_priv(indio_dev);
 
 	iio_device_unregister(indio_dev);
-	writel(ASPEED_OPERATION_MODE_POWER_DOWN,
-		data->base + ASPEED_REG_ENGINE_CONTROL);
+	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);
-- 
2.25.1

[v3 03/15] iio: adc: aspeed: set driver data when adc probe.

[Billy Tsai]

Fix the issue when adc remove will get the null driver data.

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

diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
index 7010d56ac3b9..20462cf659e4 100644
--- a/drivers/iio/adc/aspeed_adc.c
+++ b/drivers/iio/adc/aspeed_adc.c
@@ -201,6 +201,7 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 
 	data = iio_priv(indio_dev);
 	data->dev = &pdev->dev;
+	platform_set_drvdata(pdev, indio_dev);
 
 	data->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(data->base))
-- 
2.25.1

[v3 04/15] 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 20462cf659e4..d85aa31ee3b1 100644
--- a/drivers/iio/adc/aspeed_adc.c
+++ b/drivers/iio/adc/aspeed_adc.c
@@ -69,6 +69,7 @@ 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;
@@ -110,8 +111,6 @@ 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:
@@ -119,7 +118,7 @@ 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;
 
@@ -138,13 +137,11 @@ 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,
@@ -190,7 +187,6 @@ 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;
@@ -201,6 +197,7 @@ 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);
@@ -241,9 +238,7 @@ 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) |
@@ -273,8 +268,7 @@ 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

[v3 05/15] iio: adc: aspeed: Refactory model data structure

[Billy Tsai]

This patch refactory the model data structure to distinguish the
function form differnet version of aspeed adc.
- Rename the vref_voltag to vref_fixed and add vref driver data
When driver probe will check vref_fixed value and store it
to vref which isn't const value.
- Add num_channels
Make num_channles of iio device can be changed by differnet model_data
- Add need_prescaler flag and scaler_bit_width
The need_prescaler flag used to tell the driver the clock divider needs
another prescaler and the scaler_bit_width to set the clock divider
bitfiled width.

Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
---
 drivers/iio/adc/aspeed_adc.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
index d85aa31ee3b1..f03c7921d534 100644
--- a/drivers/iio/adc/aspeed_adc.c
+++ b/drivers/iio/adc/aspeed_adc.c
@@ -63,8 +63,11 @@ 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 {
@@ -75,6 +78,7 @@ struct aspeed_adc_data {
 	struct clk_hw		*clk_prescaler;
 	struct clk_hw		*clk_scaler;
 	struct reset_control	*rst;
+	int			vref;
 };
 
 #define ASPEED_CHAN(_idx, _data_reg_addr) {			\
@@ -118,7 +122,7 @@ 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;
 		*val2 = ASPEED_RESOLUTION_BITS;
 		return IIO_VAL_FRACTIONAL_LOG2;
 
@@ -312,17 +316,23 @@ 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 = 2500, // mV
 	.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 = 1800, // mV
 	.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

[v3 06/15] iio: adc: aspeed: Add vref config function

[Billy Tsai]

Add the function to check the vref_fixed 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 f03c7921d534..f260e40ab9b2 100644
--- a/drivers/iio/adc/aspeed_adc.c
+++ b/drivers/iio/adc/aspeed_adc.c
@@ -122,7 +122,7 @@ 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;
+		*val = data->vref;
 		*val2 = ASPEED_RESOLUTION_BITS;
 		return IIO_VAL_FRACTIONAL_LOG2;
 
@@ -187,6 +187,17 @@ 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) {
+		data->vref = data->model_data->vref_fixed;
+		return 0;
+	}
+	return 0;
+}
+
 static int aspeed_adc_probe(struct platform_device *pdev)
 {
 	struct iio_dev *indio_dev;
@@ -242,6 +253,10 @@ 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,
@@ -290,6 +305,7 @@ 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

[v3 07/15] iio: adc: aspeed: Set num_channels with model data

[Billy Tsai]

Use the model_data member num_channels to set the num_channels of iio
device.

Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
---
 drivers/iio/adc/aspeed_adc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
index f260e40ab9b2..2d6215a91f99 100644
--- a/drivers/iio/adc/aspeed_adc.c
+++ b/drivers/iio/adc/aspeed_adc.c
@@ -291,7 +291,7 @@ 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)
-- 
2.25.1

[v3 09/15] 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 | 92 +++++++++++++++++++++---------------
 1 file changed, 55 insertions(+), 37 deletions(-)

diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
index 52db38be9699..1c87e12a0cab 100644
--- a/drivers/iio/adc/aspeed_adc.c
+++ b/drivers/iio/adc/aspeed_adc.c
@@ -187,6 +187,27 @@ static const struct iio_info aspeed_adc_iio_info = {
 	.debugfs_reg_access = aspeed_adc_reg_access,
 };
 
+static void aspeed_adc_unregister_divider(void *data)
+{
+	struct clk_hw *clk = data;
+
+	clk_hw_unregister_divider(clk);
+}
+
+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 int aspeed_adc_vref_config(struct iio_dev *indio_dev)
 {
 	struct aspeed_adc_data *data = iio_priv(indio_dev);
@@ -232,6 +253,12 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 			&data->clk_lock);
 		if (IS_ERR(data->clk_prescaler))
 			return PTR_ERR(data->clk_prescaler);
+
+		ret = devm_add_action_or_reset(data->dev,
+					       aspeed_adc_unregister_divider,
+					       data->clk_prescaler);
+		if (ret)
+			return ret;
 		snprintf(clk_parent_name, 32, clk_name);
 		scaler_flags = CLK_SET_RATE_PARENT;
 	}
@@ -244,23 +271,30 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 		&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);
+
+	ret = devm_add_action_or_reset(data->dev, aspeed_adc_unregister_divider,
+				       data->clk_scaler);
+	if (ret)
+		return ret;
 
 	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. */
@@ -277,13 +311,19 @@ 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;
 
 	adc_engine_control_reg_val =
 		ASPEED_ADC_CTRL_CHANNEL |
@@ -299,41 +339,19 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 	indio_dev->num_channels = data->model_data->num_channels;
 
 	ret = iio_device_register(indio_dev);
-	if (ret)
-		goto iio_register_error;
-
+	if (ret) {
+		writel(FIELD_PREP(ASPEED_ADC_OP_MODE,
+				  ASPEED_ADC_OP_MODE_PWR_DOWN),
+		       data->base + ASPEED_REG_ENGINE_CONTROL);
+		return ret;
+	}
 	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);
-	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;
 }
 
-- 
2.25.1

[v3 11/15] iio: adc: aspeed: Fix the calculate error of clock.

[Billy Tsai]

The adc clcok 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 | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
index ea3e9a52fcc9..8fe7da1a651f 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>
@@ -77,6 +83,7 @@ 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;
@@ -196,6 +203,13 @@ static void aspeed_adc_unregister_divider(void *data)
 	clk_hw_unregister_divider(clk);
 }
 
+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;
@@ -312,6 +326,18 @@ 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);
 	snprintf(clk_parent_name, 32, of_clk_get_parent_name(pdev->dev.of_node, 0));
+	snprintf(clk_name, 32, "%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->clk_prescaler);
+	if (ret)
+		return ret;
+	snprintf(clk_parent_name, 32, clk_name);
 	if (data->model_data->need_prescaler) {
 		snprintf(clk_name, 32, "%s-prescaler",
 			 data->model_data->model_name);
-- 
2.25.1

Re: [v3 01/15] dt-bindings: iio: adc: Add ast2600-adc bindings

[Rob Herring]

On Mon, 16 Aug 2021 18:48:32 +0800, Billy Tsai wrote:
> Add device tree bindings document for the aspeed ast2600 adc device
> driver.
> 
> Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
> ---
>  .../bindings/iio/adc/aspeed,ast2600-adc.yaml  | 98 +++++++++++++++++++
>  1 file changed, 98 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/adc/aspeed,ast2600-adc.yaml
> 

My bot found errors running 'make DT_CHECKER_FLAGS=-m dt_binding_check'
on your patch (DT_CHECKER_FLAGS is new in v5.13):

yamllint warnings/errors:

dtschema/dtc warnings/errors:
/builds/robherring/linux-dt-review/Documentation/devicetree/bindings/iio/adc/aspeed,ast2600-adc.yaml: properties:aspeed,int_vref_mv: 'oneOf' conditional failed, one must be fixed:
	'type' is a required property
		hint: A vendor boolean property can use "type: boolean"
	Additional properties are not allowed ('enum' was unexpected)
		hint: A vendor boolean property can use "type: boolean"
	/builds/robherring/linux-dt-review/Documentation/devicetree/bindings/iio/adc/aspeed,ast2600-adc.yaml: properties:aspeed,int_vref_mv: 'oneOf' conditional failed, one must be fixed:
		'$ref' is a required property
		'allOf' is a required property
		hint: A vendor property needs a $ref to types.yaml
		from schema $id: http://devicetree.org/meta-schemas/vendor-props.yaml#
	1200 is not of type 'string'
		hint: A vendor string property with exact values has an implicit type
	2500 is not of type 'string'
		hint: A vendor string property with exact values has an implicit type
	hint: Vendor specific properties must have a type and description unless they have a defined, common suffix.
	from schema $id: http://devicetree.org/meta-schemas/vendor-props.yaml#
/builds/robherring/linux-dt-review/Documentation/devicetree/bindings/iio/adc/aspeed,ast2600-adc.yaml: ignoring, error in schema: properties: aspeed,int_vref_mv
warning: no schema found in file: ./Documentation/devicetree/bindings/iio/adc/aspeed,ast2600-adc.yaml
Documentation/devicetree/bindings/iio/adc/aspeed,ast2600-adc.example.dt.yaml:0:0: /example-0/adc@1e6e9000: failed to match any schema with compatible: ['aspeed,ast2600-adc0']
Documentation/devicetree/bindings/iio/adc/aspeed,ast2600-adc.example.dt.yaml:0:0: /example-0/adc@1e6e9100: failed to match any schema with compatible: ['aspeed,ast2600-adc1']

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/patch/1517123

This check can fail if there are any dependencies. The base for a patch
series is generally the most recent rc1.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit.