[PATCH v4 1/4] dt-bindings: iio: adc: mcp3911: add support for the whole MCP39xx family

[PATCH v4 1/4] dt-bindings: iio: adc: mcp3911: add support for the whole MCP39xx family

[Marcus Folkesson]

Microchip does have many similar chips, add those to the compatible
string as the driver support is extended.

The new supported chips are:
  - microchip,mcp3910
  - microchip,mcp3912
  - microchip,mcp3913
  - microchip,mcp3914
  - microchip,mcp3918
  - microchip,mcp3919

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---

Notes:
    v2:
        - No changes
    v3:
        - No changes
    v4:
        - No changes

 .../devicetree/bindings/iio/adc/microchip,mcp3911.yaml      | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/adc/microchip,mcp3911.yaml b/Documentation/devicetree/bindings/iio/adc/microchip,mcp3911.yaml
index f7b3fde4115a..06951ec5f5da 100644
--- a/Documentation/devicetree/bindings/iio/adc/microchip,mcp3911.yaml
+++ b/Documentation/devicetree/bindings/iio/adc/microchip,mcp3911.yaml
@@ -18,7 +18,13 @@ description: |
 properties:
   compatible:
     enum:
+      - microchip,mcp3910
       - microchip,mcp3911
+      - microchip,mcp3912
+      - microchip,mcp3913
+      - microchip,mcp3914
+      - microchip,mcp3918
+      - microchip,mcp3919
 
   reg:
     maxItems: 1
-- 
2.40.1

[PATCH v4 2/4] iio: adc: mcp3911: simplify usage of spi->dev in probe function

[Marcus Folkesson]

Replace the usage of adc->spi->dev with spi->dev to make the code prettier.

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
---

Notes:
    v4:
        - New patch in this series

 drivers/iio/adc/mcp3911.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
index 974c5bd923a6..8bbf2f7c839e 100644
--- a/drivers/iio/adc/mcp3911.c
+++ b/drivers/iio/adc/mcp3911.c
@@ -477,12 +477,12 @@ static int mcp3911_probe(struct spi_device *spi)
 	adc = iio_priv(indio_dev);
 	adc->spi = spi;
 
-	adc->vref = devm_regulator_get_optional(&adc->spi->dev, "vref");
+	adc->vref = devm_regulator_get_optional(&spi->dev, "vref");
 	if (IS_ERR(adc->vref)) {
 		if (PTR_ERR(adc->vref) == -ENODEV) {
 			adc->vref = NULL;
 		} else {
-			dev_err(&adc->spi->dev,
+			dev_err(&spi->dev,
 				"failed to get regulator (%ld)\n",
 				PTR_ERR(adc->vref));
 			return PTR_ERR(adc->vref);
@@ -499,12 +499,12 @@ static int mcp3911_probe(struct spi_device *spi)
 			return ret;
 	}
 
-	adc->clki = devm_clk_get_enabled(&adc->spi->dev, NULL);
+	adc->clki = devm_clk_get_enabled(&spi->dev, NULL);
 	if (IS_ERR(adc->clki)) {
 		if (PTR_ERR(adc->clki) == -ENOENT) {
 			adc->clki = NULL;
 		} else {
-			dev_err(&adc->spi->dev,
+			dev_err(&spi->dev,
 				"failed to get adc clk (%ld)\n",
 				PTR_ERR(adc->clki));
 			return PTR_ERR(adc->clki);
@@ -515,7 +515,7 @@ static int mcp3911_probe(struct spi_device *spi)
 	if (ret)
 		return ret;
 
-	if (device_property_read_bool(&adc->spi->dev, "microchip,data-ready-hiz"))
+	if (device_property_read_bool(&spi->dev, "microchip,data-ready-hiz"))
 		ret = mcp3911_update(adc, MCP3911_REG_STATUSCOM, MCP3911_STATUSCOM_DRHIZ,
 				0, 2);
 	else
@@ -579,7 +579,7 @@ static int mcp3911_probe(struct spi_device *spi)
 	if (ret)
 		return ret;
 
-	return devm_iio_device_register(&adc->spi->dev, indio_dev);
+	return devm_iio_device_register(&spi->dev, indio_dev);
 }
 
 static const struct of_device_id mcp3911_dt_ids[] = {
-- 
2.40.1

Re: [PATCH v4 2/4] iio: adc: mcp3911: simplify usage of spi->dev in probe function

[Andy Shevchenko]

On Tue, Aug 08, 2023 at 01:04:30PM +0200, Marcus Folkesson wrote:
> Replace the usage of adc->spi->dev with spi->dev to make the code prettier.

Suggested-by: ?

> Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>

...

> -	adc->vref = devm_regulator_get_optional(&adc->spi->dev, "vref");
> +	adc->vref = devm_regulator_get_optional(&spi->dev, "vref");

Why not

	struct device *dev = &spi->dev;

and all the rest accordingly?

>  	if (IS_ERR(adc->vref)) {
>  		if (PTR_ERR(adc->vref) == -ENODEV) {
>  			adc->vref = NULL;
>  		} else {
> -			dev_err(&adc->spi->dev,
> +			dev_err(&spi->dev,
>  				"failed to get regulator (%ld)\n",
>  				PTR_ERR(adc->vref));
>  			return PTR_ERR(adc->vref);

Actually, you may first to switch to dev_err_probe() with the above introduced

	struct device *dev = &spi->dev;
	...
			return dev_err_probe(dev, PTR_ERR(adc->vref),
					     "failed to get regulator\n",

and in the second patch do what you are doing here.

Will be much less changes and neater code at the end.

-- 
With Best Regards,
Andy Shevchenko

[PATCH v4 3/4] iio: adc: mcp3911: fix indentation

[Marcus Folkesson]

The file does not make use of indentation properly.
Fix that.

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
---

Notes:
    v4:
        - New patch in this series

 drivers/iio/adc/mcp3911.c | 97 ++++++++++++++++++++-------------------
 1 file changed, 49 insertions(+), 48 deletions(-)

diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
index 8bbf2f7c839e..8b465d2aad1a 100644
--- a/drivers/iio/adc/mcp3911.c
+++ b/drivers/iio/adc/mcp3911.c
@@ -33,7 +33,7 @@
 #define MCP3911_GAIN_VAL(ch, val)      ((val << 3 * ch) & MCP3911_GAIN_MASK(ch))
 
 #define MCP3911_REG_STATUSCOM		0x0a
-#define MCP3911_STATUSCOM_DRHIZ         BIT(12)
+#define MCP3911_STATUSCOM_DRHIZ		BIT(12)
 #define MCP3911_STATUSCOM_READ		GENMASK(7, 6)
 #define MCP3911_STATUSCOM_CH1_24WIDTH	BIT(4)
 #define MCP3911_STATUSCOM_CH0_24WIDTH	BIT(3)
@@ -112,7 +112,7 @@ static int mcp3911_write(struct mcp3911 *adc, u8 reg, u32 val, u8 len)
 }
 
 static int mcp3911_update(struct mcp3911 *adc, u8 reg, u32 mask,
-		u32 val, u8 len)
+			  u32 val, u8 len)
 {
 	u32 tmp;
 	int ret;
@@ -127,8 +127,8 @@ static int mcp3911_update(struct mcp3911 *adc, u8 reg, u32 mask,
 }
 
 static int mcp3911_write_raw_get_fmt(struct iio_dev *indio_dev,
-					struct iio_chan_spec const *chan,
-					long mask)
+				     struct iio_chan_spec const *chan,
+				     long mask)
 {
 	switch (mask) {
 	case IIO_CHAN_INFO_SCALE:
@@ -141,9 +141,9 @@ static int mcp3911_write_raw_get_fmt(struct iio_dev *indio_dev,
 }
 
 static int mcp3911_read_avail(struct iio_dev *indio_dev,
-			     struct iio_chan_spec const *chan,
-			     const int **vals, int *type, int *length,
-			     long info)
+			      struct iio_chan_spec const *chan,
+			      const int **vals, int *type, int *length,
+			      long info)
 {
 	switch (info) {
 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
@@ -212,8 +212,8 @@ static int mcp3911_read_raw(struct iio_dev *indio_dev,
 }
 
 static int mcp3911_write_raw(struct iio_dev *indio_dev,
-			    struct iio_chan_spec const *channel, int val,
-			    int val2, long mask)
+			     struct iio_chan_spec const *channel, int val,
+			     int val2, long mask)
 {
 	struct mcp3911 *adc = iio_priv(indio_dev);
 	int ret = -EINVAL;
@@ -223,12 +223,12 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
 	case IIO_CHAN_INFO_SCALE:
 		for (int i = 0; i < MCP3911_NUM_SCALES; i++) {
 			if (val == mcp3911_scale_table[i][0] &&
-				val2 == mcp3911_scale_table[i][1]) {
+			    val2 == mcp3911_scale_table[i][1]) {
 
 				adc->gain[channel->channel] = BIT(i);
 				ret = mcp3911_update(adc, MCP3911_REG_GAIN,
-						MCP3911_GAIN_MASK(channel->channel),
-						MCP3911_GAIN_VAL(channel->channel, i), 1);
+						     MCP3911_GAIN_MASK(channel->channel),
+						     MCP3911_GAIN_VAL(channel->channel, i), 1);
 			}
 		}
 		break;
@@ -246,8 +246,8 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
 
 		/* Enable offset*/
 		ret = mcp3911_update(adc, MCP3911_REG_STATUSCOM,
-				MCP3911_STATUSCOM_EN_OFFCAL,
-				MCP3911_STATUSCOM_EN_OFFCAL, 2);
+				     MCP3911_STATUSCOM_EN_OFFCAL,
+				     MCP3911_STATUSCOM_EN_OFFCAL, 2);
 		break;
 
 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
@@ -255,7 +255,7 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
 			if (val == mcp3911_osr_table[i]) {
 				val = FIELD_PREP(MCP3911_CONFIG_OSR, i);
 				ret = mcp3911_update(adc, MCP3911_REG_CONFIG, MCP3911_CONFIG_OSR,
-						val, 2);
+						     val, 2);
 				break;
 			}
 		}
@@ -279,7 +279,7 @@ static int mcp3911_calc_scale_table(struct mcp3911 *adc)
 		if (ret < 0) {
 			dev_err(&adc->spi->dev,
 				"failed to get vref voltage: %d\n",
-			       ret);
+				ret);
 			return ret;
 		}
 
@@ -305,25 +305,25 @@ static int mcp3911_calc_scale_table(struct mcp3911 *adc)
 	return 0;
 }
 
-#define MCP3911_CHAN(idx) {					\
-		.type = IIO_VOLTAGE,				\
-		.indexed = 1,					\
-		.channel = idx,					\
-		.scan_index = idx,				\
-		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
-		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
-			BIT(IIO_CHAN_INFO_OFFSET) |		\
-			BIT(IIO_CHAN_INFO_SCALE),		\
-		.info_mask_shared_by_type_available =           \
-			BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
-		.info_mask_separate_available =			\
-			BIT(IIO_CHAN_INFO_SCALE),		\
-		.scan_type = {					\
-			.sign = 's',				\
-			.realbits = 24,				\
-			.storagebits = 32,			\
-			.endianness = IIO_BE,			\
-		},						\
+#define MCP3911_CHAN(idx) {				\
+	.type = IIO_VOLTAGE,				\
+	.indexed = 1,					\
+	.channel = idx,					\
+	.scan_index = idx,				\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
+	BIT(IIO_CHAN_INFO_OFFSET) |			\
+	BIT(IIO_CHAN_INFO_SCALE),			\
+	.info_mask_shared_by_type_available =           \
+	BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),		\
+	.info_mask_separate_available =			\
+	BIT(IIO_CHAN_INFO_SCALE),			\
+	.scan_type = {					\
+		.sign = 's',				\
+		.realbits = 24,				\
+		.storagebits = 32,			\
+		.endianness = IIO_BE,			\
+	},						\
 }
 
 static const struct iio_chan_spec mcp3911_channels[] = {
@@ -355,7 +355,7 @@ static irqreturn_t mcp3911_trigger_handler(int irq, void *p)
 	ret = spi_sync_transfer(adc->spi, xfer, ARRAY_SIZE(xfer));
 	if (ret < 0) {
 		dev_warn(&adc->spi->dev,
-				"failed to get conversion data\n");
+			 "failed to get conversion data\n");
 		goto out;
 	}
 
@@ -494,7 +494,7 @@ static int mcp3911_probe(struct spi_device *spi)
 			return ret;
 
 		ret = devm_add_action_or_reset(&spi->dev,
-				mcp3911_cleanup_regulator, adc->vref);
+					       mcp3911_cleanup_regulator, adc->vref);
 		if (ret)
 			return ret;
 	}
@@ -517,10 +517,10 @@ static int mcp3911_probe(struct spi_device *spi)
 
 	if (device_property_read_bool(&spi->dev, "microchip,data-ready-hiz"))
 		ret = mcp3911_update(adc, MCP3911_REG_STATUSCOM, MCP3911_STATUSCOM_DRHIZ,
-				0, 2);
+				     0, 2);
 	else
 		ret = mcp3911_update(adc, MCP3911_REG_STATUSCOM, MCP3911_STATUSCOM_DRHIZ,
-				MCP3911_STATUSCOM_DRHIZ, 2);
+				     MCP3911_STATUSCOM_DRHIZ, 2);
 	if (ret)
 		return ret;
 
@@ -528,12 +528,12 @@ static int mcp3911_probe(struct spi_device *spi)
 	if (ret)
 		return ret;
 
-       /* Set gain to 1 for all channels */
+	/* Set gain to 1 for all channels */
 	for (int i = 0; i < MCP3911_NUM_CHANNELS; i++) {
 		adc->gain[i] = 1;
 		ret = mcp3911_update(adc, MCP3911_REG_GAIN,
-				MCP3911_GAIN_MASK(i),
-				MCP3911_GAIN_VAL(i, 0), 1);
+				     MCP3911_GAIN_MASK(i),
+				     MCP3911_GAIN_VAL(i, 0), 1);
 		if (ret)
 			return ret;
 	}
@@ -550,8 +550,8 @@ static int mcp3911_probe(struct spi_device *spi)
 
 	if (spi->irq > 0) {
 		adc->trig = devm_iio_trigger_alloc(&spi->dev, "%s-dev%d",
-				indio_dev->name,
-				iio_device_id(indio_dev));
+						   indio_dev->name,
+						   iio_device_id(indio_dev));
 		if (!adc->trig)
 			return -ENOMEM;
 
@@ -567,15 +567,16 @@ static int mcp3911_probe(struct spi_device *spi)
 		 * don't enable the interrupt to avoid extra load on the system.
 		 */
 		ret = devm_request_irq(&spi->dev, spi->irq,
-				&iio_trigger_generic_data_rdy_poll, IRQF_NO_AUTOEN | IRQF_ONESHOT,
-				indio_dev->name, adc->trig);
+				       &iio_trigger_generic_data_rdy_poll,
+				       IRQF_NO_AUTOEN | IRQF_ONESHOT,
+				       indio_dev->name, adc->trig);
 		if (ret)
 			return ret;
 	}
 
 	ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
-			NULL,
-			mcp3911_trigger_handler, NULL);
+					      NULL,
+					      mcp3911_trigger_handler, NULL);
 	if (ret)
 		return ret;
 
-- 
2.40.1

Re: [PATCH v4 3/4] iio: adc: mcp3911: fix indentation

[Andy Shevchenko]

On Tue, Aug 08, 2023 at 01:04:31PM +0200, Marcus Folkesson wrote:
> The file does not make use of indentation properly.
> Fix that.

...

>  static int mcp3911_update(struct mcp3911 *adc, u8 reg, u32 mask,
> -		u32 val, u8 len)
> +			  u32 val, u8 len)

Can val be moved to the previous line?

...

>  		if (ret < 0) {
>  			dev_err(&adc->spi->dev,
>  				"failed to get vref voltage: %d\n",
> -			       ret);
> +				ret);
>  			return ret;

With

	struct device *dev = &adc->spi->dev;

this becomes

			dev_err(dev, "failed to get vref voltage: %d\n", ret);

and one change less here.

>  		}

...

> -#define MCP3911_CHAN(idx) {					\
> -		.type = IIO_VOLTAGE,				\
> -		.indexed = 1,					\
> -		.channel = idx,					\
> -		.scan_index = idx,				\
> -		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
> -		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
> -			BIT(IIO_CHAN_INFO_OFFSET) |		\
> -			BIT(IIO_CHAN_INFO_SCALE),		\
> -		.info_mask_shared_by_type_available =           \
> -			BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
> -		.info_mask_separate_available =			\
> -			BIT(IIO_CHAN_INFO_SCALE),		\
> -		.scan_type = {					\
> -			.sign = 's',				\
> -			.realbits = 24,				\
> -			.storagebits = 32,			\
> -			.endianness = IIO_BE,			\
> -		},						\

>  }

This looks like unneeded churn to me.

...

>  	if (ret < 0) {
>  		dev_warn(&adc->spi->dev,
> -				"failed to get conversion data\n");
> +			 "failed to get conversion data\n");
>  		goto out;
>  	}

Same as above with temporary variable for struct device.

-- 
With Best Regards,
Andy Shevchenko

[PATCH v4 4/4] iio: adc: mcp3911: add support for the whole MCP39xx family

[Marcus Folkesson]

Microchip does have many similar chips, add support for those.

The new supported chips are:
  - microchip,mcp3910
  - microchip,mcp3912
  - microchip,mcp3913
  - microchip,mcp3914
  - microchip,mcp3918
  - microchip,mcp3919

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
---

Notes:
    v2:
        - Use callbacks rather than matching against enum for determine chip variants
    v3:
        - Fix cosmetics
    v4:
        - Do not pollute output variable upon error in *_get_osr() functions.
        - Fix cosmetics

 drivers/iio/adc/Kconfig   |   5 +-
 drivers/iio/adc/mcp3911.c | 459 +++++++++++++++++++++++++++++++++-----
 2 files changed, 405 insertions(+), 59 deletions(-)

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index eb2b09ef5d5b..9a9838430530 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -774,8 +774,9 @@ config MCP3911
 	select IIO_BUFFER
 	select IIO_TRIGGERED_BUFFER
 	help
-	  Say yes here to build support for Microchip Technology's MCP3911
-	  analog to digital converter.
+	  Say yes here to build support for Microchip Technology's MCP3910,
+	  MCP3911, MCP3912, MCP3913, MCP3914, MCP3918 and MCP3919
+	  analog to digital converters.
 
 	  This driver can also be built as a module. If so, the module will be
 	  called mcp3911.
diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
index 8b465d2aad1a..c033e6d29650 100644
--- a/drivers/iio/adc/mcp3911.c
+++ b/drivers/iio/adc/mcp3911.c
@@ -61,12 +61,55 @@
 #define MCP3911_REG_WRITE(reg, id)	((((reg) << 1) | ((id) << 6) | (0 << 0)) & 0xff)
 #define MCP3911_REG_MASK		GENMASK(4, 1)
 
-#define MCP3911_NUM_CHANNELS		2
 #define MCP3911_NUM_SCALES		6
 
+/* Registers compatible with MCP3910 */
+#define MCP3910_REG_STATUSCOM		0x0c
+#define MCP3910_STATUSCOM_READ		GENMASK(23, 22)
+#define MCP3910_STATUSCOM_DRHIZ		BIT(20)
+
+#define MCP3910_REG_GAIN		0x0b
+
+#define MCP3910_REG_CONFIG0		0x0d
+#define MCP3910_CONFIG0_EN_OFFCAL	BIT(23)
+#define MCP3910_CONFIG0_OSR		GENMASK(15, 13)
+
+#define MCP3910_REG_CONFIG1		0x0e
+#define MCP3910_CONFIG1_CLKEXT		BIT(6)
+#define MCP3910_CONFIG1_VREFEXT		BIT(7)
+
+#define MCP3910_REG_OFFCAL_CH0		0x0f
+#define MCP3910_OFFCAL(x)		(MCP3910_REG_OFFCAL_CH0 + x * 6)
+
+/* Maximal number of channels used by the MCP39XX family */
+#define MCP39XX_MAX_NUM_CHANNELS	8
+
 static const int mcp3911_osr_table[] = { 32, 64, 128, 256, 512, 1024, 2048, 4096 };
 static u32 mcp3911_scale_table[MCP3911_NUM_SCALES][2];
 
+enum mcp3911_id {
+	MCP3910,
+	MCP3911,
+	MCP3912,
+	MCP3913,
+	MCP3914,
+	MCP3918,
+	MCP3919,
+};
+
+struct mcp3911;
+struct mcp3911_chip_info {
+	const struct iio_chan_spec *channels;
+	unsigned int num_channels;
+
+	int (*config)(struct mcp3911 *adc);
+	int (*get_osr)(struct mcp3911 *adc, int *val);
+	int (*set_osr)(struct mcp3911 *adc, int val);
+	int (*get_offset)(struct mcp3911 *adc, int channel, int *val);
+	int (*set_offset)(struct mcp3911 *adc, int channel, int val);
+	int (*set_scale)(struct mcp3911 *adc, int channel, int val);
+};
+
 struct mcp3911 {
 	struct spi_device *spi;
 	struct mutex lock;
@@ -74,14 +117,15 @@ struct mcp3911 {
 	struct clk *clki;
 	u32 dev_addr;
 	struct iio_trigger *trig;
-	u32 gain[MCP3911_NUM_CHANNELS];
+	u32 gain[MCP39XX_MAX_NUM_CHANNELS];
+	const struct mcp3911_chip_info *chip;
 	struct {
-		u32 channels[MCP3911_NUM_CHANNELS];
+		u32 channels[MCP39XX_MAX_NUM_CHANNELS];
 		s64 ts __aligned(8);
 	} scan;
 
 	u8 tx_buf __aligned(IIO_DMA_MINALIGN);
-	u8 rx_buf[MCP3911_NUM_CHANNELS * 3];
+	u8 rx_buf[MCP39XX_MAX_NUM_CHANNELS * 3];
 };
 
 static int mcp3911_read(struct mcp3911 *adc, u8 reg, u32 *val, u8 len)
@@ -126,6 +170,104 @@ static int mcp3911_update(struct mcp3911 *adc, u8 reg, u32 mask,
 	return mcp3911_write(adc, reg, val, len);
 }
 
+static int mcp3910_get_offset(struct mcp3911 *adc, int channel, int *val)
+{
+	return mcp3911_read(adc, MCP3910_OFFCAL(channel), val, 3);
+}
+
+static int mcp3910_set_offset(struct mcp3911 *adc, int channel, int val)
+{
+	int ret;
+
+	/* Write offset */
+	ret = mcp3911_write(adc, MCP3910_OFFCAL(channel), val, 3);
+	if (ret)
+		return ret;
+
+	/* Enable offset*/
+	return mcp3911_update(adc, MCP3910_REG_CONFIG0,
+			      MCP3910_CONFIG0_EN_OFFCAL,
+			      MCP3910_CONFIG0_EN_OFFCAL, 3);
+}
+
+static int mcp3911_get_offset(struct mcp3911 *adc, int channel, int *val)
+{
+	return mcp3911_read(adc, MCP3911_OFFCAL(channel), val, 3);
+}
+
+static int mcp3911_set_offset(struct mcp3911 *adc, int channel, int val)
+{
+	int ret;
+
+	/* Write offset */
+	ret = mcp3911_write(adc, MCP3911_OFFCAL(channel), val, 3);
+	if (ret)
+		return ret;
+
+	/* Enable offset */
+	return mcp3911_update(adc, MCP3911_REG_STATUSCOM,
+			      MCP3911_STATUSCOM_EN_OFFCAL,
+			      MCP3911_STATUSCOM_EN_OFFCAL, 2);
+}
+
+static int mcp3910_get_osr(struct mcp3911 *adc, int *val)
+{
+	int ret, osr;
+
+	ret = mcp3911_read(adc, MCP3910_REG_CONFIG0, val, 3);
+	if (ret)
+		return ret;
+
+	osr = FIELD_GET(MCP3910_CONFIG0_OSR, *val);
+	*val = 32 << osr;
+	return ret;
+}
+
+static int mcp3910_set_osr(struct mcp3911 *adc, int val)
+{
+	int osr;
+
+	osr = FIELD_PREP(MCP3910_CONFIG0_OSR, val);
+	return mcp3911_update(adc, MCP3910_REG_CONFIG0,
+			      MCP3910_CONFIG0_OSR, osr, 3);
+}
+
+static int mcp3911_set_osr(struct mcp3911 *adc, int val)
+{
+	int osr;
+
+	osr = FIELD_PREP(MCP3911_CONFIG_OSR, val);
+	return mcp3911_update(adc, MCP3911_REG_CONFIG,
+			      MCP3911_CONFIG_OSR, osr, 2);
+}
+
+static int mcp3911_get_osr(struct mcp3911 *adc, int *val)
+{
+	int ret, osr;
+
+	ret = mcp3911_read(adc, MCP3911_REG_CONFIG, val, 2);
+	if (ret)
+		return ret;
+
+	osr = FIELD_GET(MCP3911_CONFIG_OSR, *val);
+	*val = 32 << osr;
+	return ret;
+}
+
+static int mcp3910_set_scale(struct mcp3911 *adc, int channel, int val)
+{
+	return mcp3911_update(adc, MCP3910_REG_GAIN,
+			      MCP3911_GAIN_MASK(channel),
+			      MCP3911_GAIN_VAL(channel, val), 3);
+}
+
+static int mcp3911_set_scale(struct mcp3911 *adc, int channel, int val)
+{
+	return mcp3911_update(adc, MCP3911_REG_GAIN,
+			      MCP3911_GAIN_MASK(channel),
+			      MCP3911_GAIN_VAL(channel, val), 1);
+}
+
 static int mcp3911_write_raw_get_fmt(struct iio_dev *indio_dev,
 				     struct iio_chan_spec const *chan,
 				     long mask)
@@ -182,20 +324,18 @@ static int mcp3911_read_raw(struct iio_dev *indio_dev,
 		break;
 
 	case IIO_CHAN_INFO_OFFSET:
-		ret = mcp3911_read(adc,
-				   MCP3911_OFFCAL(channel->channel), val, 3);
+
+		ret = adc->chip->get_offset(adc, channel->channel, val);
 		if (ret)
 			goto out;
 
 		ret = IIO_VAL_INT;
 		break;
 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
-		ret = mcp3911_read(adc, MCP3911_REG_CONFIG, val, 2);
+		ret = adc->chip->get_osr(adc, val);
 		if (ret)
 			goto out;
 
-		*val = FIELD_GET(MCP3911_CONFIG_OSR, *val);
-		*val = 32 << *val;
 		ret = IIO_VAL_INT;
 		break;
 
@@ -226,9 +366,7 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
 			    val2 == mcp3911_scale_table[i][1]) {
 
 				adc->gain[channel->channel] = BIT(i);
-				ret = mcp3911_update(adc, MCP3911_REG_GAIN,
-						     MCP3911_GAIN_MASK(channel->channel),
-						     MCP3911_GAIN_VAL(channel->channel, i), 1);
+				ret = adc->chip->set_scale(adc, channel->channel, i);
 			}
 		}
 		break;
@@ -238,24 +376,13 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
 			goto out;
 		}
 
-		/* Write offset */
-		ret = mcp3911_write(adc, MCP3911_OFFCAL(channel->channel), val,
-				    3);
-		if (ret)
-			goto out;
-
-		/* Enable offset*/
-		ret = mcp3911_update(adc, MCP3911_REG_STATUSCOM,
-				     MCP3911_STATUSCOM_EN_OFFCAL,
-				     MCP3911_STATUSCOM_EN_OFFCAL, 2);
+		ret = adc->chip->set_offset(adc, channel->channel, val);
 		break;
 
 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 		for (int i = 0; i < ARRAY_SIZE(mcp3911_osr_table); i++) {
 			if (val == mcp3911_osr_table[i]) {
-				val = FIELD_PREP(MCP3911_CONFIG_OSR, i);
-				ret = mcp3911_update(adc, MCP3911_REG_CONFIG, MCP3911_CONFIG_OSR,
-						     val, 2);
+				ret = adc->chip->set_osr(adc, i);
 				break;
 			}
 		}
@@ -326,12 +453,60 @@ static int mcp3911_calc_scale_table(struct mcp3911 *adc)
 	},						\
 }
 
+static const struct iio_chan_spec mcp3910_channels[] = {
+	MCP3911_CHAN(0),
+	MCP3911_CHAN(1),
+	IIO_CHAN_SOFT_TIMESTAMP(2),
+};
+
 static const struct iio_chan_spec mcp3911_channels[] = {
 	MCP3911_CHAN(0),
 	MCP3911_CHAN(1),
 	IIO_CHAN_SOFT_TIMESTAMP(2),
 };
 
+static const struct iio_chan_spec mcp3912_channels[] = {
+	MCP3911_CHAN(0),
+	MCP3911_CHAN(1),
+	MCP3911_CHAN(2),
+	MCP3911_CHAN(3),
+	IIO_CHAN_SOFT_TIMESTAMP(4),
+};
+
+static const struct iio_chan_spec mcp3913_channels[] = {
+	MCP3911_CHAN(0),
+	MCP3911_CHAN(1),
+	MCP3911_CHAN(2),
+	MCP3911_CHAN(3),
+	MCP3911_CHAN(4),
+	MCP3911_CHAN(5),
+	IIO_CHAN_SOFT_TIMESTAMP(6),
+};
+
+static const struct iio_chan_spec mcp3914_channels[] = {
+	MCP3911_CHAN(0),
+	MCP3911_CHAN(1),
+	MCP3911_CHAN(2),
+	MCP3911_CHAN(3),
+	MCP3911_CHAN(4),
+	MCP3911_CHAN(5),
+	MCP3911_CHAN(6),
+	MCP3911_CHAN(7),
+	IIO_CHAN_SOFT_TIMESTAMP(8),
+};
+
+static const struct iio_chan_spec mcp3918_channels[] = {
+	MCP3911_CHAN(0),
+	IIO_CHAN_SOFT_TIMESTAMP(1),
+};
+
+static const struct iio_chan_spec mcp3919_channels[] = {
+	MCP3911_CHAN(0),
+	MCP3911_CHAN(1),
+	MCP3911_CHAN(2),
+	IIO_CHAN_SOFT_TIMESTAMP(3),
+};
+
 static irqreturn_t mcp3911_trigger_handler(int irq, void *p)
 {
 	struct iio_poll_func *pf = p;
@@ -343,7 +518,7 @@ static irqreturn_t mcp3911_trigger_handler(int irq, void *p)
 			.len = 1,
 		}, {
 			.rx_buf = adc->rx_buf,
-			.len = sizeof(adc->rx_buf),
+			.len = (adc->chip->num_channels - 1) * 3,
 		},
 	};
 	int scan_index;
@@ -383,26 +558,9 @@ static const struct iio_info mcp3911_info = {
 
 static int mcp3911_config(struct mcp3911 *adc)
 {
-	struct device *dev = &adc->spi->dev;
 	u32 regval;
 	int ret;
 
-	ret = device_property_read_u32(dev, "microchip,device-addr", &adc->dev_addr);
-
-	/*
-	 * Fallback to "device-addr" due to historical mismatch between
-	 * dt-bindings and implementation
-	 */
-	if (ret)
-		device_property_read_u32(dev, "device-addr", &adc->dev_addr);
-	if (adc->dev_addr > 3) {
-		dev_err(&adc->spi->dev,
-			"invalid device address (%i). Must be in range 0-3.\n",
-			adc->dev_addr);
-		return -EINVAL;
-	}
-	dev_dbg(&adc->spi->dev, "use device address %i\n", adc->dev_addr);
-
 	ret = mcp3911_read(adc, MCP3911_REG_CONFIG, &regval, 2);
 	if (ret)
 		return ret;
@@ -439,7 +597,101 @@ static int mcp3911_config(struct mcp3911 *adc)
 	regval &= ~MCP3911_STATUSCOM_READ;
 	regval |= FIELD_PREP(MCP3911_STATUSCOM_READ, 0x02);
 
-	return  mcp3911_write(adc, MCP3911_REG_STATUSCOM, regval, 2);
+	regval &= ~MCP3911_STATUSCOM_DRHIZ;
+	if (device_property_read_bool(&adc->spi->dev, "microchip,data-ready-hiz"))
+		regval |= FIELD_PREP(MCP3911_STATUSCOM_DRHIZ, 0);
+	else
+		regval |= FIELD_PREP(MCP3911_STATUSCOM_DRHIZ, 1);
+
+	/* Disable offset to ignore any old values in offset register*/
+	regval &= ~MCP3911_STATUSCOM_EN_OFFCAL;
+
+	ret =  mcp3911_write(adc, MCP3911_REG_STATUSCOM, regval, 2);
+	if (ret)
+		return ret;
+
+	/* Set gain to 1 for all channels */
+	ret = mcp3911_read(adc, MCP3911_REG_GAIN, &regval, 1);
+	if (ret)
+		return ret;
+
+	for (int i = 0; i < adc->chip->num_channels - 1; i++) {
+		adc->gain[i] = 1;
+		regval &= ~MCP3911_GAIN_MASK(i);
+	}
+
+	return mcp3911_write(adc, MCP3911_REG_GAIN, regval, 1);
+}
+
+static int mcp3910_config(struct mcp3911 *adc)
+{
+	u32 regval;
+	int ret;
+
+	ret = mcp3911_read(adc, MCP3910_REG_CONFIG1, &regval, 3);
+	if (ret)
+		return ret;
+
+	regval &= ~MCP3910_CONFIG1_VREFEXT;
+	if (adc->vref) {
+		dev_dbg(&adc->spi->dev, "use external voltage reference\n");
+		regval |= FIELD_PREP(MCP3910_CONFIG1_VREFEXT, 1);
+	} else {
+		dev_dbg(&adc->spi->dev,
+			"use internal voltage reference (1.2V)\n");
+		regval |= FIELD_PREP(MCP3910_CONFIG1_VREFEXT, 0);
+	}
+
+	regval &= ~MCP3910_CONFIG1_CLKEXT;
+	if (adc->clki) {
+		dev_dbg(&adc->spi->dev, "use external clock as clocksource\n");
+		regval |= FIELD_PREP(MCP3910_CONFIG1_CLKEXT, 1);
+	} else {
+		dev_dbg(&adc->spi->dev,
+			"use crystal oscillator as clocksource\n");
+		regval |= FIELD_PREP(MCP3910_CONFIG1_CLKEXT, 0);
+	}
+
+	ret = mcp3911_write(adc, MCP3910_REG_CONFIG1, regval, 3);
+	if (ret)
+		return ret;
+
+	ret = mcp3911_read(adc, MCP3910_REG_STATUSCOM, &regval, 3);
+	if (ret)
+		return ret;
+
+	/* Address counter incremented, cycle through register types */
+	regval &= ~MCP3910_STATUSCOM_READ;
+	regval |= FIELD_PREP(MCP3910_STATUSCOM_READ, 0x02);
+
+
+	regval &= ~MCP3910_STATUSCOM_DRHIZ;
+	if (device_property_read_bool(&adc->spi->dev, "microchip,data-ready-hiz"))
+		regval |= FIELD_PREP(MCP3910_STATUSCOM_DRHIZ, 0);
+	else
+		regval |= FIELD_PREP(MCP3910_STATUSCOM_DRHIZ, 1);
+
+	ret = mcp3911_write(adc, MCP3910_REG_STATUSCOM, regval, 3);
+	if (ret)
+		return ret;
+
+	/* Set gain to 1 for all channels */
+	ret = mcp3911_read(adc, MCP3910_REG_GAIN, &regval, 3);
+	if (ret)
+		return ret;
+
+	for (int i = 0; i < adc->chip->num_channels - 1; i++) {
+		adc->gain[i] = 1;
+		regval &= ~MCP3911_GAIN_MASK(i);
+	}
+	ret = mcp3911_write(adc, MCP3910_REG_GAIN, regval, 3);
+	if (ret)
+		return ret;
+
+	/* Disable offset to ignore any old values in offset register */
+	return mcp3911_update(adc, MCP3910_REG_CONFIG0,
+			      MCP3910_CONFIG0_EN_OFFCAL,
+			      MCP3910_CONFIG0_EN_OFFCAL, 3);
 }
 
 static void mcp3911_cleanup_regulator(void *vref)
@@ -476,6 +728,7 @@ static int mcp3911_probe(struct spi_device *spi)
 
 	adc = iio_priv(indio_dev);
 	adc->spi = spi;
+	adc->chip = spi_get_device_match_data(spi);
 
 	adc->vref = devm_regulator_get_optional(&spi->dev, "vref");
 	if (IS_ERR(adc->vref)) {
@@ -511,16 +764,24 @@ static int mcp3911_probe(struct spi_device *spi)
 		}
 	}
 
-	ret = mcp3911_config(adc);
+	ret = device_property_read_u32(&spi->dev, "microchip,device-addr", &adc->dev_addr);
+
+	/*
+	 * Fallback to "device-addr" due to historical mismatch between
+	 * dt-bindings and implementation.
+	 */
 	if (ret)
-		return ret;
+		device_property_read_u32(&spi->dev, "device-addr", &adc->dev_addr);
+	if (adc->dev_addr > 3) {
+		dev_err(&spi->dev,
+			"invalid device address (%i). Must be in range 0-3.\n",
+			adc->dev_addr);
+		return -EINVAL;
+	}
+	dev_dbg(&spi->dev, "use device address %i\n", adc->dev_addr);
 
-	if (device_property_read_bool(&spi->dev, "microchip,data-ready-hiz"))
-		ret = mcp3911_update(adc, MCP3911_REG_STATUSCOM, MCP3911_STATUSCOM_DRHIZ,
-				     0, 2);
-	else
-		ret = mcp3911_update(adc, MCP3911_REG_STATUSCOM, MCP3911_STATUSCOM_DRHIZ,
-				     MCP3911_STATUSCOM_DRHIZ, 2);
+
+	ret = adc->chip->config(adc);
 	if (ret)
 		return ret;
 
@@ -529,7 +790,7 @@ static int mcp3911_probe(struct spi_device *spi)
 		return ret;
 
 	/* Set gain to 1 for all channels */
-	for (int i = 0; i < MCP3911_NUM_CHANNELS; i++) {
+	for (int i = 0; i < adc->chip->num_channels - 1; i++) {
 		adc->gain[i] = 1;
 		ret = mcp3911_update(adc, MCP3911_REG_GAIN,
 				     MCP3911_GAIN_MASK(i),
@@ -543,8 +804,8 @@ static int mcp3911_probe(struct spi_device *spi)
 	indio_dev->info = &mcp3911_info;
 	spi_set_drvdata(spi, indio_dev);
 
-	indio_dev->channels = mcp3911_channels;
-	indio_dev->num_channels = ARRAY_SIZE(mcp3911_channels);
+	indio_dev->channels = adc->chip->channels;
+	indio_dev->num_channels = adc->chip->num_channels;
 
 	mutex_init(&adc->lock);
 
@@ -583,14 +844,98 @@ static int mcp3911_probe(struct spi_device *spi)
 	return devm_iio_device_register(&spi->dev, indio_dev);
 }
 
+static const struct mcp3911_chip_info mcp3911_chip_info[] = {
+	[MCP3910] = {
+		.channels = mcp3910_channels,
+		.num_channels = ARRAY_SIZE(mcp3910_channels),
+		.config = mcp3910_config,
+		.get_osr = mcp3910_get_osr,
+		.set_osr = mcp3910_set_osr,
+		.get_offset = mcp3910_get_offset,
+		.set_offset = mcp3910_set_offset,
+		.set_scale = mcp3910_set_scale,
+	},
+	[MCP3911] = {
+		.channels = mcp3911_channels,
+		.num_channels = ARRAY_SIZE(mcp3911_channels),
+		.config = mcp3911_config,
+		.get_osr = mcp3911_get_osr,
+		.set_osr = mcp3911_set_osr,
+		.get_offset = mcp3911_get_offset,
+		.set_offset = mcp3911_set_offset,
+		.set_scale = mcp3911_set_scale,
+	},
+	[MCP3912] = {
+		.channels = mcp3912_channels,
+		.num_channels = ARRAY_SIZE(mcp3912_channels),
+		.config = mcp3910_config,
+		.get_osr = mcp3910_get_osr,
+		.set_osr = mcp3910_set_osr,
+		.get_offset = mcp3910_get_offset,
+		.set_offset = mcp3910_set_offset,
+		.set_scale = mcp3910_set_scale,
+	},
+	[MCP3913] = {
+		.channels = mcp3913_channels,
+		.num_channels = ARRAY_SIZE(mcp3913_channels),
+		.config = mcp3910_config,
+		.get_osr = mcp3910_get_osr,
+		.set_osr = mcp3910_set_osr,
+		.get_offset = mcp3910_get_offset,
+		.set_offset = mcp3910_set_offset,
+		.set_scale = mcp3910_set_scale,
+	},
+	[MCP3914] = {
+		.channels = mcp3914_channels,
+		.num_channels = ARRAY_SIZE(mcp3914_channels),
+		.config = mcp3910_config,
+		.get_osr = mcp3910_get_osr,
+		.set_osr = mcp3910_set_osr,
+		.get_offset = mcp3910_get_offset,
+		.set_offset = mcp3910_set_offset,
+		.set_scale = mcp3910_set_scale,
+	},
+	[MCP3918] = {
+		.channels = mcp3918_channels,
+		.num_channels = ARRAY_SIZE(mcp3918_channels),
+		.config = mcp3910_config,
+		.get_osr = mcp3910_get_osr,
+		.set_osr = mcp3910_set_osr,
+		.get_offset = mcp3910_get_offset,
+		.set_offset = mcp3910_set_offset,
+		.set_scale = mcp3910_set_scale,
+	},
+	[MCP3919] = {
+		.channels = mcp3919_channels,
+		.num_channels = ARRAY_SIZE(mcp3919_channels),
+		.config = mcp3910_config,
+		.get_osr = mcp3910_get_osr,
+		.set_osr = mcp3910_set_osr,
+		.get_offset = mcp3910_get_offset,
+		.set_offset = mcp3910_set_offset,
+		.set_scale = mcp3910_set_scale,
+	},
+};
 static const struct of_device_id mcp3911_dt_ids[] = {
-	{ .compatible = "microchip,mcp3911" },
+	{ .compatible = "microchip,mcp3910", .data = &mcp3911_chip_info[MCP3910] },
+	{ .compatible = "microchip,mcp3911", .data = &mcp3911_chip_info[MCP3911] },
+	{ .compatible = "microchip,mcp3912", .data = &mcp3911_chip_info[MCP3912] },
+	{ .compatible = "microchip,mcp3913", .data = &mcp3911_chip_info[MCP3913] },
+	{ .compatible = "microchip,mcp3914", .data = &mcp3911_chip_info[MCP3914] },
+	{ .compatible = "microchip,mcp3918", .data = &mcp3911_chip_info[MCP3918] },
+	{ .compatible = "microchip,mcp3919", .data = &mcp3911_chip_info[MCP3919] },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, mcp3911_dt_ids);
 
 static const struct spi_device_id mcp3911_id[] = {
-	{ "mcp3911", 0 },
+	{ "mcp3910", (kernel_ulong_t)&mcp3911_chip_info[MCP3910] },
+	{ "mcp3911", (kernel_ulong_t)&mcp3911_chip_info[MCP3911] },
+	{ "mcp3912", (kernel_ulong_t)&mcp3911_chip_info[MCP3912] },
+	{ "mcp3913", (kernel_ulong_t)&mcp3911_chip_info[MCP3913] },
+	{ "mcp3914", (kernel_ulong_t)&mcp3911_chip_info[MCP3914] },
+	{ "mcp3918", (kernel_ulong_t)&mcp3911_chip_info[MCP3918] },
+	{ "mcp3919", (kernel_ulong_t)&mcp3911_chip_info[MCP3919] },
 	{ }
 };
 MODULE_DEVICE_TABLE(spi, mcp3911_id);
-- 
2.40.1

Re: [PATCH v4 4/4] iio: adc: mcp3911: add support for the whole MCP39xx family

[Andy Shevchenko]

On Tue, Aug 08, 2023 at 01:04:32PM +0200, Marcus Folkesson wrote:
> Microchip does have many similar chips, add support for those.

...

>  	help
> -	  Say yes here to build support for Microchip Technology's MCP3911
> -	  analog to digital converter.
> +	  Say yes here to build support for Microchip Technology's MCP3910,
> +	  MCP3911, MCP3912, MCP3913, MCP3914, MCP3918 and MCP3919
> +	  analog to digital converters.

For maintenance this can be written as

	  Say yes here to build support for one of the following
	  Microchip Technology's analog to digital converters:
	    MCP3910, MCP3911, MCP3912, MCP3913, MCP3914,
	    MCP3918, MCP3919

>  	  This driver can also be built as a module. If so, the module will be
>  	  called mcp3911.

...

> +#define MCP3910_OFFCAL(x)		(MCP3910_REG_OFFCAL_CH0 + x * 6)

Inconsistent macro implementation, i.e. you need to use (x).

...

> +static int mcp3910_get_osr(struct mcp3911 *adc, int *val)
> +{
> +	int ret, osr;

Strictly speaking osr can't be negative, otherwise it's a UB below.

	u32 osr = FIELD_GET(MCP3910_CONFIG0_OSR, *val);
	int ret;

and why val is int?

> +	ret = mcp3911_read(adc, MCP3910_REG_CONFIG0, val, 3);
> +	if (ret)
> +		return ret;
> +
> +	osr = FIELD_GET(MCP3910_CONFIG0_OSR, *val);
> +	*val = 32 << osr;
> +	return ret;
> +}

...

> +static int mcp3910_set_osr(struct mcp3911 *adc, int val)
> +{

> +	int osr;
> +
> +	osr = FIELD_PREP(MCP3910_CONFIG0_OSR, val);

Can be on one line.

> +	return mcp3911_update(adc, MCP3910_REG_CONFIG0,
> +			      MCP3910_CONFIG0_OSR, osr, 3);
> +}

...

> +static int mcp3911_set_osr(struct mcp3911 *adc, int val)
> +static int mcp3911_get_osr(struct mcp3911 *adc, int *val)

As per above comments.

...

> +	if (adc->vref) {
> +		dev_dbg(&adc->spi->dev, "use external voltage reference\n");
> +		regval |= FIELD_PREP(MCP3910_CONFIG1_VREFEXT, 1);
> +	} else {

> +		dev_dbg(&adc->spi->dev,
> +			"use internal voltage reference (1.2V)\n");


As per previous patch comments

		dev_dbg(dev, "use internal voltage reference (1.2V)\n");

> +		regval |= FIELD_PREP(MCP3910_CONFIG1_VREFEXT, 0);
> +	}

...

> +	if (adc->clki) {
> +		dev_dbg(&adc->spi->dev, "use external clock as clocksource\n");
> +		regval |= FIELD_PREP(MCP3910_CONFIG1_CLKEXT, 1);
> +	} else {
> +		dev_dbg(&adc->spi->dev,
> +			"use crystal oscillator as clocksource\n");

Ditto.

> +		regval |= FIELD_PREP(MCP3910_CONFIG1_CLKEXT, 0);
> +	}

...

> +	if (device_property_read_bool(&adc->spi->dev, "microchip,data-ready-hiz"))

This also becomes shorter.

One trick to make it even shorter:

	if (device_property_present(dev, "microchip,data-ready-hiz"))

> +		regval |= FIELD_PREP(MCP3910_STATUSCOM_DRHIZ, 0);
> +	else
> +		regval |= FIELD_PREP(MCP3910_STATUSCOM_DRHIZ, 1);

...

> +	ret = device_property_read_u32(&spi->dev, "microchip,device-addr", &adc->dev_addr);

I would move it after the comment. It will be more visible what we are
expecting and what the legacy is.


> +	/*
> +	 * Fallback to "device-addr" due to historical mismatch between
> +	 * dt-bindings and implementation.
> +	 */

	ret = device_property_read_u32(dev, "microchip,device-addr", &adc->dev_addr);

>  	if (ret)
> -		return ret;
> +		device_property_read_u32(&spi->dev, "device-addr", &adc->dev_addr);

> +	if (adc->dev_addr > 3) {
> +		dev_err(&spi->dev,
> +			"invalid device address (%i). Must be in range 0-3.\n",
> +			adc->dev_addr);
> +		return -EINVAL;

		return dev_err_probe(...);

> +	}

...

> +	dev_dbg(&spi->dev, "use device address %i\n", adc->dev_addr);

Is it useful?

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v4 4/4] iio: adc: mcp3911: add support for the whole MCP39xx family

[Marcus Folkesson]

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> ...
> 
> > +#define MCP3910_OFFCAL(x)		(MCP3910_REG_OFFCAL_CH0 + x * 6)
> 
> Inconsistent macro implementation, i.e. you need to use (x).

Sorry, I do not get you


[...]

> > +static int mcp3910_get_osr(struct mcp3911 *adc, int *val)
> > +{
> > +	int ret, osr;
> 
> Strictly speaking osr can't be negative, otherwise it's a UB below.
> 
> 	u32 osr = FIELD_GET(MCP3910_CONFIG0_OSR, *val);
> 	int ret;
> 
> and why val is int?

I will change val to u32 for *_get_osr(), *_set_osr() and *_set_scale().

[...]

> > +	if (device_property_read_bool(&adc->spi->dev, "microchip,data-ready-hiz"))
> 
> This also becomes shorter.
> 
> One trick to make it even shorter:
> 
> 	if (device_property_present(dev, "microchip,data-ready-hiz"))

Thank you, I wasn't aware of device_property_present().

[...]

> 
> > +	dev_dbg(&spi->dev, "use device address %i\n", adc->dev_addr);
> 
> Is it useful?

Yes, I think so.

> 
> -- 
> With Best Regards,
> Andy Shevchenko
> 
> 

Best regards,
Marcus Folkesson

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Re: [PATCH v4 4/4] iio: adc: mcp3911: add support for the whole MCP39xx family

[Jonathan Cameron]

On Wed, 9 Aug 2023 08:41:05 +0200
Marcus Folkesson <marcus.folkesson@gmail.com> wrote:

> > ...
> >   
> > > +#define MCP3910_OFFCAL(x)		(MCP3910_REG_OFFCAL_CH0 + x * 6)  
> > 
> > Inconsistent macro implementation, i.e. you need to use (x).  
> 
> Sorry, I do not get you
> 
> 
> [...]
> 
> > > +static int mcp3910_get_osr(struct mcp3911 *adc, int *val)
> > > +{
> > > +	int ret, osr;  
> > 
> > Strictly speaking osr can't be negative, otherwise it's a UB below.
> > 
> > 	u32 osr = FIELD_GET(MCP3910_CONFIG0_OSR, *val);
> > 	int ret;
> > 
> > and why val is int?  
> 
> I will change val to u32 for *_get_osr(), *_set_osr() and *_set_scale().
> 
> [...]
> 
> > > +	if (device_property_read_bool(&adc->spi->dev, "microchip,data-ready-hiz"))  
> > 
> > This also becomes shorter.
> > 
> > One trick to make it even shorter:
> > 
> > 	if (device_property_present(dev, "microchip,data-ready-hiz"))  
> 
> Thank you, I wasn't aware of device_property_present().

I know the read_bool function is direct equivalent of this but where a property
is a flag, it feels more natural to me to check it with that one.
read_present() feels more appropriate for where you want to know a more
complex property is present.

Doesn't matter that much either way however so up to you.

> 
> [...]
> 
> >   
> > > +	dev_dbg(&spi->dev, "use device address %i\n", adc->dev_addr);  
> > 
> > Is it useful?  
> 
> Yes, I think so.
> 
> > 
> > -- 
> > With Best Regards,
> > Andy Shevchenko
> > 
> >   
> 
> Best regards,
> Marcus Folkesson

Re: [PATCH v4 4/4] iio: adc: mcp3911: add support for the whole MCP39xx family

[Krzysztof Kozlowski]

On 09/08/2023 20:02, Jonathan Cameron wrote:
> On Wed, 9 Aug 2023 08:41:05 +0200
> Marcus Folkesson <marcus.folkesson@gmail.com> wrote:
> 
>>> ...
>>>   
>>>> +#define MCP3910_OFFCAL(x)		(MCP3910_REG_OFFCAL_CH0 + x * 6)  
>>>
>>> Inconsistent macro implementation, i.e. you need to use (x).  
>>
>> Sorry, I do not get you
>>
>>
>> [...]
>>
>>>> +static int mcp3910_get_osr(struct mcp3911 *adc, int *val)
>>>> +{
>>>> +	int ret, osr;  
>>>
>>> Strictly speaking osr can't be negative, otherwise it's a UB below.
>>>
>>> 	u32 osr = FIELD_GET(MCP3910_CONFIG0_OSR, *val);
>>> 	int ret;
>>>
>>> and why val is int?  
>>
>> I will change val to u32 for *_get_osr(), *_set_osr() and *_set_scale().
>>
>> [...]
>>
>>>> +	if (device_property_read_bool(&adc->spi->dev, "microchip,data-ready-hiz"))  
>>>
>>> This also becomes shorter.
>>>
>>> One trick to make it even shorter:
>>>
>>> 	if (device_property_present(dev, "microchip,data-ready-hiz"))  
>>
>> Thank you, I wasn't aware of device_property_present().
> 
> I know the read_bool function is direct equivalent of this but where a property
> is a flag, it feels more natural to me to check it with that one.
> read_present() feels more appropriate for where you want to know a more
> complex property is present.
> 
> Doesn't matter that much either way however so up to you.

For the OF, of_property_read_bool() is indeed preferred. Is there
device-xxx() equivalent?

Best regards,
Krzysztof

Re: [PATCH v4 4/4] iio: adc: mcp3911: add support for the whole MCP39xx family

[Andy Shevchenko]

On Wed, Aug 09, 2023 at 08:14:54PM +0200, Krzysztof Kozlowski wrote:
> On 09/08/2023 20:02, Jonathan Cameron wrote:
> > On Wed, 9 Aug 2023 08:41:05 +0200
> > Marcus Folkesson <marcus.folkesson@gmail.com> wrote:

...

> >>> Inconsistent macro implementation, i.e. you need to use (x).
> >>
> >> Sorry, I do not get you

In other macros you avoid ambiguity of the parameter, so they can be evaluated
properly, and not here.


...

> >>>> +	if (device_property_read_bool(&adc->spi->dev, "microchip,data-ready-hiz"))

(1)

> >>> This also becomes shorter.
> >>>
> >>> One trick to make it even shorter:
> >>>
> >>> 	if (device_property_present(dev, "microchip,data-ready-hiz"))
> >>
> >> Thank you, I wasn't aware of device_property_present().
> > 
> > I know the read_bool function is direct equivalent of this but where a property
> > is a flag, it feels more natural to me to check it with that one.
> > read_present() feels more appropriate for where you want to know a more
> > complex property is present.
> > 
> > Doesn't matter that much either way however so up to you.
> 
> For the OF, of_property_read_bool() is indeed preferred. Is there
> device-xxx() equivalent?

See (1) above ?

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v4 4/4] iio: adc: mcp3911: add support for the whole MCP39xx family

[Marcus Folkesson]

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On Thu, Aug 10, 2023 at 04:44:20PM +0300, Andy Shevchenko wrote:
> On Wed, Aug 09, 2023 at 08:14:54PM +0200, Krzysztof Kozlowski wrote:
> > On 09/08/2023 20:02, Jonathan Cameron wrote:
> > > On Wed, 9 Aug 2023 08:41:05 +0200
> > > Marcus Folkesson <marcus.folkesson@gmail.com> wrote:
> 
> ...
> 
> > >>> Inconsistent macro implementation, i.e. you need to use (x).
> > >>
> > >> Sorry, I do not get you
> 
> In other macros you avoid ambiguity of the parameter, so they can be evaluated
> properly, and not here.


Hrmf, I missed that I had asked about this before I sent out v5. Such a shame.

I got you now, thanks.

I agree that maybe it should be 'ch' instead.
Already existing macros for channel and offcal use 'x' though, so in
that case should be changed as well.

#define MCP3911_CHANNEL(x)		(MCP3911_REG_CHANNEL0 + x * 3)
#define MCP3911_OFFCAL(x)		(MCP3911_REG_OFFCAL_CH0 + x * 6)

[...]

> 
> See (1) above ?
> 
> -- 
> With Best Regards,
> Andy Shevchenko
> 
> 

Best regards,
Marcus Folkesson

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