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iio: adc: npcm: add Arbel NPCM8XX support

PATCH Superseded Tomer Maimon 3 participants 5 messages Jul 13, 2022

Subsystems (3)
Device tree bindings IIO Arm/nuvoton npcm architecture

v2 of 3 Superseded Latest is v3 →

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Tomer Maimon

author maintainer
#0 lore raw

v2 cover iio: adc: npcm: add Arbel NPCM8XX support

This patch set adds Arbel NPCM8XX Analog-to-Digital Converter (ADC) support to ADC NPCM driver.

The NPCM8XX ADC is a 12-bit converter for eight channel inputs.

The NPCM ADC driver tested on NPCM845 evaluation board.

Addressed comments from:
- Rob Herring : https://www.spinics.net/lists/kernel/msg4433755.html
- Krzysztof Kozlowski: https://www.spinics.net/lists/kernel/msg4434546.html
- Andy Shevchenko : https://www.spinics.net/lists/devicetree/msg516844.html

Changes since version 1:
- Modify dt-binding compatible property.
- Use device_get_match_data function instead of_match_node function.

Tomer Maimon (2):
dt-bindings: iio: adc: npcm: Add npcm845 compatible string
iio: adc: npcm: Add NPCM8XX support

 .../bindings/iio/adc/nuvoton,npcm750-adc.yaml |  7 ++--
 drivers/iio/adc/npcm_adc.c                    | 35 +++++++++++++++----
 2 files changed, 33 insertions(+), 9 deletions(-)
Signature · 1 line
2.33.0
author maintainer
#1 lore raw

PATCH v2 1/2 dt-bindings: iio: adc: npcm: Add npcm845 compatible string

Add a compatible string for Nuvoton BMC NPCM845 ADC.

Signed-off-by Tomer Maimon <[email protected]>
---
 .../devicetree/bindings/iio/adc/nuvoton,npcm750-adc.yaml   | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
Documentation/devicetree/bindings/iio/adc/nuvoton,npcm750-adc.yaml +5 -2
index 001cf263b7d5..fede2aa64092 100644
@@ -10,11 +10,14 @@ maintainers:
   - Tomer Maimon <[email protected]>
 
 description:
-  The NPCM ADC is a 10-bit converter for eight channel inputs.
+  The NPCM7XX ADC is a 10-bit converter and NPCM8XX ADC is a 12-bit converter,
+  both have eight channel inputs.
 
 properties:
   compatible:
-    const: nuvoton,npcm750-adc
+    enum:
+      - nuvoton,npcm750-adc
+      - nuvoton,npcm845-adc
 
   reg:
     maxItems: 1
Signature · 1 line
2.33.0
author maintainer
#3 lore raw

PATCH v2 2/2 iio: adc: npcm: Add NPCM8XX support

In reply to Tomer Maimon

Adding ADC NPCM8XX support to NPCM ADC driver.
ADC NPCM8XX uses a different resolution and voltage reference.

As part of adding NPCM8XX support:
- Add NPCM8XX specific compatible string.
- Add data to handle architecture-specific ADC parameters.

Signed-off-by Tomer Maimon <[email protected]>
---
 drivers/iio/adc/npcm_adc.c | 35 ++++++++++++++++++++++++++++-------
 1 file changed, 28 insertions(+), 7 deletions(-)
drivers/iio/adc/npcm_adc.c +28 -7
index f7bc0bb7f112..406038b5c0d6 100644
@@ -16,6 +16,12 @@
 #include <linux/uaccess.h>
 #include <linux/reset.h>
 
+struct npcm_adc_info {
+	u32 data_mask;
+	u32 internal_vref;
+	u32 res_bits;
+};
+
 struct npcm_adc {
 	bool int_status;
 	u32 adc_sample_hz;

@@ -34,6 +40,7 @@ struct npcm_adc {
 	 * has finished.
 	 */
 	struct mutex lock;
+	struct npcm_adc_info *data;
 };
 
 /* ADC registers */

@@ -52,13 +59,21 @@ struct npcm_adc {
 #define NPCM_ADCCON_CH(x)		((x) << 24)
 #define NPCM_ADCCON_DIV_SHIFT		1
 #define NPCM_ADCCON_DIV_MASK		GENMASK(8, 1)
-#define NPCM_ADC_DATA_MASK(x)		((x) & GENMASK(9, 0))
 
 #define NPCM_ADC_ENABLE		(NPCM_ADCCON_ADC_EN | NPCM_ADCCON_ADC_INT_EN)
 
 /* ADC General Definition */
-#define NPCM_RESOLUTION_BITS		10
-#define NPCM_INT_VREF_MV		2000
+static const struct npcm_adc_info npxm7xx_adc_info = {
+	.data_mask = GENMASK(9, 0),
+	.internal_vref = 2048,
+	.res_bits = 10,
+};
+
+static const struct npcm_adc_info npxm8xx_adc_info = {
+	.data_mask = GENMASK(11, 0),
+	.internal_vref = 1229,
+	.res_bits = 12,
+};
 
 #define NPCM_ADC_CHAN(ch) {					\
 	.type = IIO_VOLTAGE,					\

@@ -129,7 +144,8 @@ static int npcm_adc_read(struct npcm_adc *info, int *val, u8 channel)
 	if (ret < 0)
 		return ret;
 
-	*val = NPCM_ADC_DATA_MASK(ioread32(info->regs + NPCM_ADCDATA));
+	*val = ioread32(info->regs + NPCM_ADCDATA);
+	*val &= info->data->data_mask;
 
 	return 0;
 }

@@ -157,9 +173,9 @@ static int npcm_adc_read_raw(struct iio_dev *indio_dev,
 			vref_uv = regulator_get_voltage(info->vref);
 			*val = vref_uv / 1000;
 		} else {
-			*val = NPCM_INT_VREF_MV;
+			*val = info->data->internal_vref;
 		}
-		*val2 = NPCM_RESOLUTION_BITS;
+		*val2 = info->data->res_bits;
 		return IIO_VAL_FRACTIONAL_LOG2;
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		*val = info->adc_sample_hz;

@@ -176,7 +192,8 @@ static const struct iio_info npcm_adc_iio_info = {
 };
 
 static const struct of_device_id npcm_adc_match[] = {
-	{ .compatible = "nuvoton,npcm750-adc", },
+	{ .compatible = "nuvoton,npcm750-adc", .data = &npxm7xx_adc_info},
+	{ .compatible = "nuvoton,npcm845-adc", .data = &npxm8xx_adc_info},
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, npcm_adc_match);

@@ -196,6 +213,10 @@ static int npcm_adc_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	info = iio_priv(indio_dev);
 
+	info->data = (struct npcm_adc_info *)device_get_match_data(dev);
+	if (!info->data)
+		return -EINVAL;
+
 	mutex_init(&info->lock);
 
 	info->dev = &pdev->dev;
Signature · 1 line
2.33.0
#4 lore raw

Re: [PATCH v2 2/2] iio: adc: npcm: Add NPCM8XX support

Quoted 7 lines · Tomer Maimon

Adding ADC NPCM8XX support to NPCM ADC driver.
ADC NPCM8XX uses a different resolution and voltage reference.

As part of adding NPCM8XX support:
- Add NPCM8XX specific compatible string.
- Add data to handle architecture-specific ADC parameters.

...

Quoted 1 line

+ struct npcm_adc_info *data;

Can it be const?

...

Quoted 1 line

+ info->data = (struct npcm_adc_info *)device_get_match_data(dev);

...and hence no dropping qualifier is needed here, i.e. remove the casting.

Signature · 2 lines
With Best Regards,
Andy Shevchenko