[PATCH V6 0/5] iio: accel: sca3300: add compatible for scl3300

[PATCH V6 0/5] iio: accel: sca3300: add compatible for scl3300

[LI Qingwu]

The current driver support sca3300 only, modified to support SCL3300.
Verified with SCL3300 on IMX8MM.

SCL3300 is a three-axis accelerometer sensor with angle output, 
the change adds the support of scl3300 and inclination data output.


Changes in v6: 
  - Fix the warning of precedence issue,
    Reported-by: kernel test robot <lkp@intel.com>
  - Modify the commit message.
  - Fix the check of the for-loop issue,
    delete the blank line, and change ">=" to "==".

LI Qingwu (5):
  dt-bindings: iio: accel: sca3300: Document murata,scl3300
  iio: accel: sca3300: add define for temp channel for reuse.
  iio: accel: sca3300: modified to support multi chips
  iio: accel: sca3300: Add support for SCL3300
  iio: accel: sca3300: Add inclination channels

 .../bindings/iio/accel/murata,sca3300.yaml    |   1 +
 drivers/iio/accel/sca3300.c                   | 312 +++++++++++++++---
 2 files changed, 260 insertions(+), 53 deletions(-)

-- 
2.25.1

[PATCH V6 1/5] dt-bindings: iio: accel: sca3300: Document murata,scl3300

[LI Qingwu]

Add DT bindings for Murata scl3300 inclinometer.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>
---
 Documentation/devicetree/bindings/iio/accel/murata,sca3300.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/iio/accel/murata,sca3300.yaml b/Documentation/devicetree/bindings/iio/accel/murata,sca3300.yaml
index 55fd3548e3b6..f6e2a16a710b 100644
--- a/Documentation/devicetree/bindings/iio/accel/murata,sca3300.yaml
+++ b/Documentation/devicetree/bindings/iio/accel/murata,sca3300.yaml
@@ -17,6 +17,7 @@ properties:
   compatible:
     enum:
       - murata,sca3300
+      - murata,scl3300
 
   reg:
     maxItems: 1
-- 
2.25.1

[PATCH V6 2/5] iio: accel: sca3300: add define for temp channel for reuse.

[LI Qingwu]

Add define of SCA3300_TEMP_CHANNEL for reuse.

Signed-off-by: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>
---
 drivers/iio/accel/sca3300.c | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/drivers/iio/accel/sca3300.c b/drivers/iio/accel/sca3300.c
index f7ef8ecfd34a..ff16d2cc8c70 100644
--- a/drivers/iio/accel/sca3300.c
+++ b/drivers/iio/accel/sca3300.c
@@ -72,22 +72,24 @@ enum sca3300_scan_indexes {
 	},								\
 }
 
+#define SCA3300_TEMP_CHANNEL(index, reg) {				\
+		.type = IIO_TEMP,					\
+		.address = reg,						\
+		.scan_index = index,					\
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
+		.scan_type = {						\
+			.sign = 's',					\
+			.realbits = 16,					\
+			.storagebits = 16,				\
+			.endianness = IIO_CPU,				\
+		},							\
+}
+
 static const struct iio_chan_spec sca3300_channels[] = {
 	SCA3300_ACCEL_CHANNEL(SCA3300_ACC_X, 0x1, X),
 	SCA3300_ACCEL_CHANNEL(SCA3300_ACC_Y, 0x2, Y),
 	SCA3300_ACCEL_CHANNEL(SCA3300_ACC_Z, 0x3, Z),
-	{
-		.type = IIO_TEMP,
-		.address = 0x5,
-		.scan_index = SCA3300_TEMP,
-		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
-		.scan_type = {
-			.sign = 's',
-			.realbits = 16,
-			.storagebits = 16,
-			.endianness = IIO_CPU,
-		},
-	},
+	SCA3300_TEMP_CHANNEL(SCA3300_TEMP, 0x05),
 	IIO_CHAN_SOFT_TIMESTAMP(4),
 };
 
-- 
2.25.1

[PATCH V6 3/5] iio: accel: sca3300: modified to support multi chips

[LI Qingwu]

Prepare the way for multiple chips and additional channels:
- Modify the driver to read the device ID and load the corresponding
  sensor information from the table to support multiple chips
- Add prepares for the addition of extra channels
- Prepare for handling the operation modes for multiple chips

Signed-off-by: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>
---
 drivers/iio/accel/sca3300.c | 186 ++++++++++++++++++++++++++++--------
 1 file changed, 145 insertions(+), 41 deletions(-)

diff --git a/drivers/iio/accel/sca3300.c b/drivers/iio/accel/sca3300.c
index ff16d2cc8c70..bc6e0213e4aa 100644
--- a/drivers/iio/accel/sca3300.c
+++ b/drivers/iio/accel/sca3300.c
@@ -93,15 +93,35 @@ static const struct iio_chan_spec sca3300_channels[] = {
 	IIO_CHAN_SOFT_TIMESTAMP(4),
 };
 
-static const int sca3300_lp_freq[] = {70, 70, 70, 10};
-static const int sca3300_accel_scale[][2] = {{0, 370}, {0, 741}, {0, 185}, {0, 185}};
+static const int sca3300_lp_freq[] = {70, 10};
+static const int sca3300_lp_freq_map[] = {0, 0, 0, 1};
 
+static const int sca3300_accel_scale[][2] = {{0, 370}, {0, 741}, {0, 185}};
+static const int sca3300_accel_scale_map[] = {0, 1, 2, 2};
+
+static const int sca3300_avail_modes_map[] = {0, 1, 2, 3};
 static const unsigned long sca3300_scan_masks[] = {
 	BIT(SCA3300_ACC_X) | BIT(SCA3300_ACC_Y) | BIT(SCA3300_ACC_Z) |
 	BIT(SCA3300_TEMP),
 	0
 };
 
+struct sca3300_chip_info {
+	const char *name;
+	const unsigned long *scan_masks;
+	const struct iio_chan_spec *channels;
+	u8 num_channels;
+	u8 num_accel_scales;
+	const int (*accel_scale)[2];
+	const int *accel_scale_map;
+	u8 num_freqs;
+	const int *freq_table;
+	const int *freq_map;
+	const int *avail_modes_table;
+	u8 num_avail_modes;
+	u8 chip_id;
+};
+
 /**
  * struct sca3300_data - device data
  * @spi: SPI device structure
@@ -117,10 +137,29 @@ struct sca3300_data {
 		s16 channels[4];
 		s64 ts __aligned(sizeof(s64));
 	} scan;
+	const struct sca3300_chip_info *chip;
 	u8 txbuf[4] ____cacheline_aligned;
 	u8 rxbuf[4];
 };
 
+static const struct sca3300_chip_info sca3300_chip_tbl[] = {
+	{
+		.name = "sca3300",
+		.scan_masks = sca3300_scan_masks,
+		.channels = sca3300_channels,
+		.num_channels = ARRAY_SIZE(sca3300_channels),
+		.num_accel_scales = ARRAY_SIZE(sca3300_accel_scale)*2,
+		.accel_scale = sca3300_accel_scale,
+		.accel_scale_map = sca3300_accel_scale_map,
+		.num_freqs = ARRAY_SIZE(sca3300_lp_freq),
+		.freq_table = sca3300_lp_freq,
+		.freq_map = sca3300_lp_freq_map,
+		.avail_modes_table = sca3300_avail_modes_map,
+		.num_avail_modes = 4,
+		.chip_id = SCA3300_WHOAMI_ID,
+	},
+};
+
 DECLARE_CRC8_TABLE(sca3300_crc_table);
 
 static int sca3300_transfer(struct sca3300_data *sca_data, int *val)
@@ -227,36 +266,80 @@ static int sca3300_write_reg(struct sca3300_data *sca_data, u8 reg, int val)
 	return sca3300_error_handler(sca_data);
 }
 
+static int sca3300_set_op_mode(struct sca3300_data *sca_data, int index)
+{
+	if ((index < 0) || (index >= sca_data->chip->num_avail_modes))
+		return -EINVAL;
+
+	return sca3300_write_reg(sca_data, SCA3300_REG_MODE,
+				 sca_data->chip->avail_modes_table[index]);
+}
+
+static int sca3300_get_op_mode(struct sca3300_data *sca_data, int *index)
+{
+	int reg_val;
+	int ret;
+	int i;
+
+	ret = sca3300_read_reg(sca_data, SCA3300_REG_MODE, &reg_val);
+	if (ret)
+		return ret;
+
+	reg_val &= GENMASK(1, 0);
+	for (i = 0; i < sca_data->chip->num_avail_modes; i++) {
+		if (sca_data->chip->avail_modes_table[i] == reg_val)
+			break;
+	}
+	if (i == sca_data->chip->num_avail_modes)
+		return -EINVAL;
+
+	*index = i;
+	return 0;
+}
+
+static int sca3300_set_frequency(struct sca3300_data *data, int val)
+{
+	const struct sca3300_chip_info *chip = data->chip;
+	unsigned int index;
+	unsigned int i;
+
+	if (sca3300_get_op_mode(data, &index))
+		return -EINVAL;
+
+	for (i = 0; i < chip->num_avail_modes; i++) {
+		if ((val == chip->freq_table[chip->freq_map[i]]) &&
+		    (chip->accel_scale[chip->accel_scale_map[index]] ==
+		     chip->accel_scale[chip->accel_scale_map[i]]))
+			break;
+	}
+	if (i == chip->num_avail_modes)
+		return -EINVAL;
+
+	return sca3300_set_op_mode(data, i);
+}
+
 static int sca3300_write_raw(struct iio_dev *indio_dev,
 			     struct iio_chan_spec const *chan,
 			     int val, int val2, long mask)
 {
 	struct sca3300_data *data = iio_priv(indio_dev);
-	int reg_val;
-	int ret;
+	int index;
 	int i;
 
 	switch (mask) {
 	case IIO_CHAN_INFO_SCALE:
-		if (val)
+		if (chan->type != IIO_ACCEL)
 			return -EINVAL;
-
-		for (i = 0; i < ARRAY_SIZE(sca3300_accel_scale); i++) {
-			if (val2 == sca3300_accel_scale[i][1])
-				return sca3300_write_reg(data, SCA3300_REG_MODE, i);
+		for (i = 0; i < data->chip->num_avail_modes; i++) {
+			index = data->chip->accel_scale_map[i];
+			if ((val  == data->chip->accel_scale[index][0]) &&
+			    (val2 == data->chip->accel_scale[index][1])) {
+				return sca3300_set_op_mode(data, i);
+			}
 		}
 		return -EINVAL;
-
 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
-		ret = sca3300_read_reg(data, SCA3300_REG_MODE, &reg_val);
-		if (ret)
-			return ret;
-		/* freq. change is possible only for mode 3 and 4 */
-		if (reg_val == 2 && val == sca3300_lp_freq[3])
-			return sca3300_write_reg(data, SCA3300_REG_MODE, 3);
-		if (reg_val == 3 && val == sca3300_lp_freq[2])
-			return sca3300_write_reg(data, SCA3300_REG_MODE, 2);
-		return -EINVAL;
+		return sca3300_set_frequency(data, val);
 	default:
 		return -EINVAL;
 	}
@@ -267,8 +350,8 @@ static int sca3300_read_raw(struct iio_dev *indio_dev,
 			    int *val, int *val2, long mask)
 {
 	struct sca3300_data *data = iio_priv(indio_dev);
+	int index;
 	int ret;
-	int reg_val;
 
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
@@ -277,17 +360,25 @@ static int sca3300_read_raw(struct iio_dev *indio_dev,
 			return ret;
 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_SCALE:
-		ret = sca3300_read_reg(data, SCA3300_REG_MODE, &reg_val);
+		ret = sca3300_get_op_mode(data, &index);
 		if (ret)
 			return ret;
-		*val = 0;
-		*val2 = sca3300_accel_scale[reg_val][1];
-		return IIO_VAL_INT_PLUS_MICRO;
+		switch (chan->type) {
+		case IIO_ACCEL:
+			index = data->chip->accel_scale_map[index];
+			*val = data->chip->accel_scale[index][0];
+			*val2 = data->chip->accel_scale[index][1];
+			return IIO_VAL_INT_PLUS_MICRO;
+		default:
+			return -EINVAL;
+		}
 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
-		ret = sca3300_read_reg(data, SCA3300_REG_MODE, &reg_val);
+
+		ret = sca3300_get_op_mode(data, &index);
 		if (ret)
 			return ret;
-		*val = sca3300_lp_freq[reg_val];
+		index = data->chip->freq_map[index];
+		*val = data->chip->freq_table[index];
 		return IIO_VAL_INT;
 	default:
 		return -EINVAL;
@@ -331,6 +422,7 @@ static int sca3300_init(struct sca3300_data *sca_data,
 {
 	int value = 0;
 	int ret;
+	int i;
 
 	ret = sca3300_write_reg(sca_data, SCA3300_REG_MODE,
 				SCA3300_MODE_SW_RESET);
@@ -347,12 +439,17 @@ static int sca3300_init(struct sca3300_data *sca_data,
 	if (ret)
 		return ret;
 
-	if (value != SCA3300_WHOAMI_ID) {
-		dev_err(&sca_data->spi->dev,
-			"device id not expected value, %d != %u\n",
-			value, SCA3300_WHOAMI_ID);
+	for (i = 0; i < ARRAY_SIZE(sca3300_chip_tbl); i++) {
+		if (sca3300_chip_tbl[i].chip_id == value)
+			break;
+	}
+	if (i == ARRAY_SIZE(sca3300_chip_tbl)) {
+		dev_err(&sca_data->spi->dev, "unknown chip id %x\n", value);
 		return -ENODEV;
 	}
+
+	sca_data->chip = &sca3300_chip_tbl[i];
+
 	return 0;
 }
 
@@ -384,15 +481,21 @@ static int sca3300_read_avail(struct iio_dev *indio_dev,
 			      const int **vals, int *type, int *length,
 			      long mask)
 {
+	struct sca3300_data *data = iio_priv(indio_dev);
 	switch (mask) {
 	case IIO_CHAN_INFO_SCALE:
-		*vals = (const int *)sca3300_accel_scale;
-		*length = ARRAY_SIZE(sca3300_accel_scale) * 2 - 2;
-		*type = IIO_VAL_INT_PLUS_MICRO;
-		return IIO_AVAIL_LIST;
+		switch (chan->type) {
+		case IIO_ACCEL:
+			*vals = (const int *)data->chip->accel_scale;
+			*length = data->chip->num_accel_scales;
+			*type = IIO_VAL_INT_PLUS_MICRO;
+			return IIO_AVAIL_LIST;
+		default:
+			return -EINVAL;
+		}
 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
-		*vals = &sca3300_lp_freq[2];
-		*length = 2;
+		*vals = (const int *)data->chip->freq_table;
+		*length = data->chip->num_freqs;
 		*type = IIO_VAL_INT;
 		return IIO_AVAIL_LIST;
 	default:
@@ -424,11 +527,6 @@ static int sca3300_probe(struct spi_device *spi)
 	crc8_populate_msb(sca3300_crc_table, SCA3300_CRC8_POLYNOMIAL);
 
 	indio_dev->info = &sca3300_info;
-	indio_dev->name = SCA3300_ALIAS;
-	indio_dev->modes = INDIO_DIRECT_MODE;
-	indio_dev->channels = sca3300_channels;
-	indio_dev->num_channels = ARRAY_SIZE(sca3300_channels);
-	indio_dev->available_scan_masks = sca3300_scan_masks;
 
 	ret = sca3300_init(sca_data, indio_dev);
 	if (ret) {
@@ -436,6 +534,12 @@ static int sca3300_probe(struct spi_device *spi)
 		return ret;
 	}
 
+	indio_dev->name = sca_data->chip->name;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = sca_data->chip->channels;
+	indio_dev->num_channels = sca_data->chip->num_channels;
+	indio_dev->available_scan_masks = sca_data->chip->scan_masks;
+
 	ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
 					      iio_pollfunc_store_time,
 					      sca3300_trigger_handler, NULL);
-- 
2.25.1

Re: [PATCH V6 3/5] iio: accel: sca3300: modified to support multi chips

[Jonathan Cameron]

On Fri, 13 May 2022 12:41:33 +0000
LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn> wrote:

> Prepare the way for multiple chips and additional channels:
> - Modify the driver to read the device ID and load the corresponding
>   sensor information from the table to support multiple chips
> - Add prepares for the addition of extra channels
> - Prepare for handling the operation modes for multiple chips
> 
> Signed-off-by: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>
A few requests for additional comments inline where the handling
is 'unusual' enough to be non obvious to figure out.

Thanks,

Jonathan

> ---
>  drivers/iio/accel/sca3300.c | 186 ++++++++++++++++++++++++++++--------
>  1 file changed, 145 insertions(+), 41 deletions(-)
> 
> diff --git a/drivers/iio/accel/sca3300.c b/drivers/iio/accel/sca3300.c
> index ff16d2cc8c70..bc6e0213e4aa 100644
> --- a/drivers/iio/accel/sca3300.c
> +++ b/drivers/iio/accel/sca3300.c
> @@ -93,15 +93,35 @@ static const struct iio_chan_spec sca3300_channels[] = {
>  	IIO_CHAN_SOFT_TIMESTAMP(4),
>  };
>  
> -static const int sca3300_lp_freq[] = {70, 70, 70, 10};
> -static const int sca3300_accel_scale[][2] = {{0, 370}, {0, 741}, {0, 185}, {0, 185}};
> +static const int sca3300_lp_freq[] = {70, 10};
> +static const int sca3300_lp_freq_map[] = {0, 0, 0, 1};
>  
> +static const int sca3300_accel_scale[][2] = {{0, 370}, {0, 741}, {0, 185}};
> +static const int sca3300_accel_scale_map[] = {0, 1, 2, 2};
> +
> +static const int sca3300_avail_modes_map[] = {0, 1, 2, 3};
>  static const unsigned long sca3300_scan_masks[] = {
>  	BIT(SCA3300_ACC_X) | BIT(SCA3300_ACC_Y) | BIT(SCA3300_ACC_Z) |
>  	BIT(SCA3300_TEMP),
>  	0
>  };
>  
> +struct sca3300_chip_info {
> +	const char *name;
> +	const unsigned long *scan_masks;
> +	const struct iio_chan_spec *channels;
> +	u8 num_channels;
> +	u8 num_accel_scales;
> +	const int (*accel_scale)[2];
> +	const int *accel_scale_map;
> +	u8 num_freqs;
> +	const int *freq_table;
> +	const int *freq_map;
> +	const int *avail_modes_table;
> +	u8 num_avail_modes;
> +	u8 chip_id;
> +};
> +
>  /**
>   * struct sca3300_data - device data
>   * @spi: SPI device structure
> @@ -117,10 +137,29 @@ struct sca3300_data {
>  		s16 channels[4];
>  		s64 ts __aligned(sizeof(s64));
>  	} scan;
> +	const struct sca3300_chip_info *chip;

Needs documentation as struct sca3300_data has kernel doc.
Also, move this above scan.  That way all the buffers used
for various purposes will remain together.

>  	u8 txbuf[4] ____cacheline_aligned;
>  	u8 rxbuf[4];
>  };
>  
> +static const struct sca3300_chip_info sca3300_chip_tbl[] = {
> +	{
> +		.name = "sca3300",
> +		.scan_masks = sca3300_scan_masks,
> +		.channels = sca3300_channels,
> +		.num_channels = ARRAY_SIZE(sca3300_channels),
> +		.num_accel_scales = ARRAY_SIZE(sca3300_accel_scale)*2,
> +		.accel_scale = sca3300_accel_scale,
> +		.accel_scale_map = sca3300_accel_scale_map,
> +		.num_freqs = ARRAY_SIZE(sca3300_lp_freq),
> +		.freq_table = sca3300_lp_freq,
> +		.freq_map = sca3300_lp_freq_map,
> +		.avail_modes_table = sca3300_avail_modes_map,
> +		.num_avail_modes = 4,
> +		.chip_id = SCA3300_WHOAMI_ID,
> +	},
> +};
> +
>  DECLARE_CRC8_TABLE(sca3300_crc_table);
>  
>  static int sca3300_transfer(struct sca3300_data *sca_data, int *val)
> @@ -227,36 +266,80 @@ static int sca3300_write_reg(struct sca3300_data *sca_data, u8 reg, int val)
>  	return sca3300_error_handler(sca_data);
>  }
>  
> +static int sca3300_set_op_mode(struct sca3300_data *sca_data, int index)
> +{
> +	if ((index < 0) || (index >= sca_data->chip->num_avail_modes))
> +		return -EINVAL;
> +
> +	return sca3300_write_reg(sca_data, SCA3300_REG_MODE,
> +				 sca_data->chip->avail_modes_table[index]);
> +}
> +
> +static int sca3300_get_op_mode(struct sca3300_data *sca_data, int *index)
> +{
> +	int reg_val;
> +	int ret;
> +	int i;
> +
> +	ret = sca3300_read_reg(sca_data, SCA3300_REG_MODE, &reg_val);
> +	if (ret)
> +		return ret;
> +
> +	reg_val &= GENMASK(1, 0);
> +	for (i = 0; i < sca_data->chip->num_avail_modes; i++) {
> +		if (sca_data->chip->avail_modes_table[i] == reg_val)
> +			break;
> +	}
> +	if (i == sca_data->chip->num_avail_modes)
> +		return -EINVAL;
> +
> +	*index = i;
> +	return 0;
> +}
> +
> +static int sca3300_set_frequency(struct sca3300_data *data, int val)
> +{
> +	const struct sca3300_chip_info *chip = data->chip;
> +	unsigned int index;
> +	unsigned int i;
> +
> +	if (sca3300_get_op_mode(data, &index))
> +		return -EINVAL;
> +
> +	for (i = 0; i < chip->num_avail_modes; i++) {
> +		if ((val == chip->freq_table[chip->freq_map[i]]) &&

The conditions being checked here are far from obvious, so I think this would benefit
from an explanatory comment.

Something along the lines of,
"Find a mode in which the requested sampling frequency is available
 and the scaling currently set is retained".



> +		    (chip->accel_scale[chip->accel_scale_map[index]] ==
> +		     chip->accel_scale[chip->accel_scale_map[i]]))
> +			break;
> +	}
> +	if (i == chip->num_avail_modes)
> +		return -EINVAL;
> +
> +	return sca3300_set_op_mode(data, i);
> +}
> +
>  static int sca3300_write_raw(struct iio_dev *indio_dev,
>  			     struct iio_chan_spec const *chan,
>  			     int val, int val2, long mask)
>  {
>  	struct sca3300_data *data = iio_priv(indio_dev);
> -	int reg_val;
> -	int ret;
> +	int index;
>  	int i;
>  
>  	switch (mask) {
>  	case IIO_CHAN_INFO_SCALE:
> -		if (val)
> +		if (chan->type != IIO_ACCEL)
>  			return -EINVAL;
> -
> -		for (i = 0; i < ARRAY_SIZE(sca3300_accel_scale); i++) {
> -			if (val2 == sca3300_accel_scale[i][1])
> -				return sca3300_write_reg(data, SCA3300_REG_MODE, i);
> +		for (i = 0; i < data->chip->num_avail_modes; i++) {
> +			index = data->chip->accel_scale_map[i];

Also a comment here that we are letting scale take priority over
sampling frequency. That makes sense given we can only ever end up increasing
the sampling frequency which is unlikely to be a problem.

> +			if ((val  == data->chip->accel_scale[index][0]) &&
> +			    (val2 == data->chip->accel_scale[index][1])) {
> +				return sca3300_set_op_mode(data, i);
> +			}
>  		}
>  		return -EINVAL;
> -
>  	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
> -		ret = sca3300_read_reg(data, SCA3300_REG_MODE, &reg_val);
> -		if (ret)
> -			return ret;
> -		/* freq. change is possible only for mode 3 and 4 */
> -		if (reg_val == 2 && val == sca3300_lp_freq[3])
> -			return sca3300_write_reg(data, SCA3300_REG_MODE, 3);
> -		if (reg_val == 3 && val == sca3300_lp_freq[2])
> -			return sca3300_write_reg(data, SCA3300_REG_MODE, 2);
> -		return -EINVAL;
> +		return sca3300_set_frequency(data, val);
>  	default:
>  		return -EINVAL;
>  	}

Re: [PATCH V6 3/5] iio: accel: sca3300: modified to support multi chips

[Tomas Melin]

Hi,

On 14/05/2022 17:10, Jonathan Cameron wrote:
> On Fri, 13 May 2022 12:41:33 +0000
> LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn> wrote:
> 
>> Prepare the way for multiple chips and additional channels:
>> - Modify the driver to read the device ID and load the corresponding
>>   sensor information from the table to support multiple chips
>> - Add prepares for the addition of extra channels
>> - Prepare for handling the operation modes for multiple chips
>>
>> Signed-off-by: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>
> A few requests for additional comments inline where the handling
> is 'unusual' enough to be non obvious to figure out.
> 
> Thanks,
> 
> Jonathan
> 
>> ---
>>  drivers/iio/accel/sca3300.c | 186 ++++++++++++++++++++++++++++--------
>>  1 file changed, 145 insertions(+), 41 deletions(-)
>>
>> diff --git a/drivers/iio/accel/sca3300.c b/drivers/iio/accel/sca3300.c
>> index ff16d2cc8c70..bc6e0213e4aa 100644
>> --- a/drivers/iio/accel/sca3300.c
>> +++ b/drivers/iio/accel/sca3300.c
>> @@ -93,15 +93,35 @@ static const struct iio_chan_spec sca3300_channels[] = {
>>  	IIO_CHAN_SOFT_TIMESTAMP(4),
>>  };
>>  
>> -static const int sca3300_lp_freq[] = {70, 70, 70, 10};
>> -static const int sca3300_accel_scale[][2] = {{0, 370}, {0, 741}, {0, 185}, {0, 185}};
>> +static const int sca3300_lp_freq[] = {70, 10};
>> +static const int sca3300_lp_freq_map[] = {0, 0, 0, 1};
>>  
>> +static const int sca3300_accel_scale[][2] = {{0, 370}, {0, 741}, {0, 185}};
>> +static const int sca3300_accel_scale_map[] = {0, 1, 2, 2};
>> +
>> +static const int sca3300_avail_modes_map[] = {0, 1, 2, 3};
>>  static const unsigned long sca3300_scan_masks[] = {
>>  	BIT(SCA3300_ACC_X) | BIT(SCA3300_ACC_Y) | BIT(SCA3300_ACC_Z) |
>>  	BIT(SCA3300_TEMP),
>>  	0
>>  };
>>  
>> +struct sca3300_chip_info {
>> +	const char *name;
>> +	const unsigned long *scan_masks;
>> +	const struct iio_chan_spec *channels;
>> +	u8 num_channels;
>> +	u8 num_accel_scales;
>> +	const int (*accel_scale)[2];
>> +	const int *accel_scale_map;
>> +	u8 num_freqs;
>> +	const int *freq_table;
>> +	const int *freq_map;
>> +	const int *avail_modes_table;
>> +	u8 num_avail_modes;
>> +	u8 chip_id;
>> +};
>> +
>>  /**
>>   * struct sca3300_data - device data
>>   * @spi: SPI device structure
>> @@ -117,10 +137,29 @@ struct sca3300_data {
>>  		s16 channels[4];
>>  		s64 ts __aligned(sizeof(s64));
>>  	} scan;
>> +	const struct sca3300_chip_info *chip;
> 
> Needs documentation as struct sca3300_data has kernel doc.
> Also, move this above scan.  That way all the buffers used
> for various purposes will remain together.
> 
>>  	u8 txbuf[4] ____cacheline_aligned;
>>  	u8 rxbuf[4];
>>  };
>>  
>> +static const struct sca3300_chip_info sca3300_chip_tbl[] = {
>> +	{
>> +		.name = "sca3300",
>> +		.scan_masks = sca3300_scan_masks,
>> +		.channels = sca3300_channels,
>> +		.num_channels = ARRAY_SIZE(sca3300_channels),
>> +		.num_accel_scales = ARRAY_SIZE(sca3300_accel_scale)*2,
>> +		.accel_scale = sca3300_accel_scale,
>> +		.accel_scale_map = sca3300_accel_scale_map,
>> +		.num_freqs = ARRAY_SIZE(sca3300_lp_freq),
>> +		.freq_table = sca3300_lp_freq,
>> +		.freq_map = sca3300_lp_freq_map,
>> +		.avail_modes_table = sca3300_avail_modes_map,
>> +		.num_avail_modes = 4,
>> +		.chip_id = SCA3300_WHOAMI_ID,
>> +	},
>> +};
>> +
>>  DECLARE_CRC8_TABLE(sca3300_crc_table);
>>  
>>  static int sca3300_transfer(struct sca3300_data *sca_data, int *val)
>> @@ -227,36 +266,80 @@ static int sca3300_write_reg(struct sca3300_data *sca_data, u8 reg, int val)
>>  	return sca3300_error_handler(sca_data);
>>  }
>>  
>> +static int sca3300_set_op_mode(struct sca3300_data *sca_data, int index)
>> +{
>> +	if ((index < 0) || (index >= sca_data->chip->num_avail_modes))
>> +		return -EINVAL;
>> +
>> +	return sca3300_write_reg(sca_data, SCA3300_REG_MODE,
>> +				 sca_data->chip->avail_modes_table[index]);
>> +}
>> +
>> +static int sca3300_get_op_mode(struct sca3300_data *sca_data, int *index)
>> +{
>> +	int reg_val;
>> +	int ret;
>> +	int i;
>> +
>> +	ret = sca3300_read_reg(sca_data, SCA3300_REG_MODE, &reg_val);
>> +	if (ret)
>> +		return ret;
>> +
>> +	reg_val &= GENMASK(1, 0);
>> +	for (i = 0; i < sca_data->chip->num_avail_modes; i++) {
>> +		if (sca_data->chip->avail_modes_table[i] == reg_val)
>> +			break;
>> +	}
>> +	if (i == sca_data->chip->num_avail_modes)
>> +		return -EINVAL;
>> +
>> +	*index = i;
>> +	return 0;
>> +}
>> +
>> +static int sca3300_set_frequency(struct sca3300_data *data, int val)
>> +{
>> +	const struct sca3300_chip_info *chip = data->chip;
>> +	unsigned int index;
>> +	unsigned int i;
>> +
>> +	if (sca3300_get_op_mode(data, &index))
>> +		return -EINVAL;
>> +
>> +	for (i = 0; i < chip->num_avail_modes; i++) {
>> +		if ((val == chip->freq_table[chip->freq_map[i]]) &&
> 
> The conditions being checked here are far from obvious, so I think this would benefit
> from an explanatory comment.
> 
> Something along the lines of,
> "Find a mode in which the requested sampling frequency is available
>  and the scaling currently set is retained".


In addition to a comment, how about small restructure of loop and giving
local variables that tell the purpose, something like


...

unsigned int opmode_scale, new_scale;

opmode_scale = chip->accel_scale[chip->accel_scale_map[index]];

/*
* Find a mode in which the requested sampling frequency is available
* and the scaling currently set is retained
*/
for (i = 0; i < chip->num_avail_modes; i++) {
    if (val == chip->freq_table[chip->freq_map[i]]) {
        new_scale = chip->accel_scale[chip->accel_scale_map[i]]);	
        if (opmode_scale == new_scale)
            break;
    }
}


That way it's IMHO more clear what we are comparing.

Thanks,
Tomas


> 
> 
> 
>> +		    (chip->accel_scale[chip->accel_scale_map[index]] ==
>> +		     chip->accel_scale[chip->accel_scale_map[i]]))
>> +			break;
>> +	}
>> +	if (i == chip->num_avail_modes)
>> +		return -EINVAL;
>> +
>> +	return sca3300_set_op_mode(data, i);
>> +}
>> +
>>  static int sca3300_write_raw(struct iio_dev *indio_dev,
>>  			     struct iio_chan_spec const *chan,
>>  			     int val, int val2, long mask)
>>  {
>>  	struct sca3300_data *data = iio_priv(indio_dev);
>> -	int reg_val;
>> -	int ret;
>> +	int index;
>>  	int i;
>>  
>>  	switch (mask) {
>>  	case IIO_CHAN_INFO_SCALE:
>> -		if (val)
>> +		if (chan->type != IIO_ACCEL)
>>  			return -EINVAL;
>> -
>> -		for (i = 0; i < ARRAY_SIZE(sca3300_accel_scale); i++) {
>> -			if (val2 == sca3300_accel_scale[i][1])
>> -				return sca3300_write_reg(data, SCA3300_REG_MODE, i);
>> +		for (i = 0; i < data->chip->num_avail_modes; i++) {
>> +			index = data->chip->accel_scale_map[i];
> 
> Also a comment here that we are letting scale take priority over
> sampling frequency. That makes sense given we can only ever end up increasing
> the sampling frequency which is unlikely to be a problem.
> 
>> +			if ((val  == data->chip->accel_scale[index][0]) &&
>> +			    (val2 == data->chip->accel_scale[index][1])) {
>> +				return sca3300_set_op_mode(data, i);
>> +			}
>>  		}
>>  		return -EINVAL;
>> -
>>  	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
>> -		ret = sca3300_read_reg(data, SCA3300_REG_MODE, &reg_val);
>> -		if (ret)
>> -			return ret;
>> -		/* freq. change is possible only for mode 3 and 4 */
>> -		if (reg_val == 2 && val == sca3300_lp_freq[3])
>> -			return sca3300_write_reg(data, SCA3300_REG_MODE, 3);
>> -		if (reg_val == 3 && val == sca3300_lp_freq[2])
>> -			return sca3300_write_reg(data, SCA3300_REG_MODE, 2);
>> -		return -EINVAL;
>> +		return sca3300_set_frequency(data, val);
>>  	default:
>>  		return -EINVAL;
>>  	}

Re: [PATCH V6 3/5] iio: accel: sca3300: modified to support multi chips

[Jonathan Cameron]

> >> +static int sca3300_set_frequency(struct sca3300_data *data, int val)
> >> +{
> >> +	const struct sca3300_chip_info *chip = data->chip;
> >> +	unsigned int index;
> >> +	unsigned int i;
> >> +
> >> +	if (sca3300_get_op_mode(data, &index))
> >> +		return -EINVAL;
> >> +
> >> +	for (i = 0; i < chip->num_avail_modes; i++) {
> >> +		if ((val == chip->freq_table[chip->freq_map[i]]) &&  
> > 
> > The conditions being checked here are far from obvious, so I think this would benefit
> > from an explanatory comment.
> > 
> > Something along the lines of,
> > "Find a mode in which the requested sampling frequency is available
> >  and the scaling currently set is retained".  
> 
> 
> In addition to a comment, how about small restructure of loop and giving
> local variables that tell the purpose, something like
> 
> 
> ...
> 
> unsigned int opmode_scale, new_scale;
> 
> opmode_scale = chip->accel_scale[chip->accel_scale_map[index]];
> 
> /*
> * Find a mode in which the requested sampling frequency is available
> * and the scaling currently set is retained
> */
> for (i = 0; i < chip->num_avail_modes; i++) {
>     if (val == chip->freq_table[chip->freq_map[i]]) {
>         new_scale = chip->accel_scale[chip->accel_scale_map[i]]);	
>         if (opmode_scale == new_scale)
>             break;
>     }
> }
> 
> 
> That way it's IMHO more clear what we are comparing.
LGTM.

Thanks,

Jonathan

> 
> Thanks,
> Tomas

[PATCH V6 4/5] iio: accel: sca3300: Add support for SCL3300

[LI Qingwu]

Add support for Murata SCL3300, a 3-axis MEMS accelerometer.
Same as SCA3300, it has the accelerometer and temperature output.

Datasheet: www.murata.com/en-us/products/sensor/inclinometer/overview/lineup/scl3300
Signed-off-by: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>
---
 drivers/iio/accel/sca3300.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/drivers/iio/accel/sca3300.c b/drivers/iio/accel/sca3300.c
index bc6e0213e4aa..3dcb4296fad2 100644
--- a/drivers/iio/accel/sca3300.c
+++ b/drivers/iio/accel/sca3300.c
@@ -38,6 +38,7 @@
 /* Device ID */
 #define SCA3300_REG_WHOAMI	0x10
 #define SCA3300_WHOAMI_ID	0x51
+#define SCL3300_WHOAMI_ID	0xC1
 
 /* Device return status and mask */
 #define SCA3300_VALUE_RS_ERROR	0x3
@@ -96,10 +97,18 @@ static const struct iio_chan_spec sca3300_channels[] = {
 static const int sca3300_lp_freq[] = {70, 10};
 static const int sca3300_lp_freq_map[] = {0, 0, 0, 1};
 
+static const int scl3300_lp_freq[] = {40, 70, 10};
+static const int scl3300_lp_freq_map[] = {0, 1, 2};
+
 static const int sca3300_accel_scale[][2] = {{0, 370}, {0, 741}, {0, 185}};
 static const int sca3300_accel_scale_map[] = {0, 1, 2, 2};
 
+static const int scl3300_accel_scale[][2] = {{0, 167}, {0, 333}, {0, 83}};
+static const int scl3300_accel_scale_map[] = {0, 1, 2};
+
 static const int sca3300_avail_modes_map[] = {0, 1, 2, 3};
+static const int scl3300_avail_modes_map[] = {0, 1, 3};
+
 static const unsigned long sca3300_scan_masks[] = {
 	BIT(SCA3300_ACC_X) | BIT(SCA3300_ACC_Y) | BIT(SCA3300_ACC_Z) |
 	BIT(SCA3300_TEMP),
@@ -158,6 +167,20 @@ static const struct sca3300_chip_info sca3300_chip_tbl[] = {
 		.num_avail_modes = 4,
 		.chip_id = SCA3300_WHOAMI_ID,
 	},
+	{	.scan_masks = sca3300_scan_masks,
+		.channels = sca3300_channels,
+		.num_channels = ARRAY_SIZE(sca3300_channels),
+		.num_accel_scales = ARRAY_SIZE(scl3300_accel_scale)*2,
+		.accel_scale = scl3300_accel_scale,
+		.accel_scale_map = scl3300_accel_scale_map,
+		.num_freqs = ARRAY_SIZE(scl3300_lp_freq),
+		.freq_table = scl3300_lp_freq,
+		.freq_map = scl3300_lp_freq_map,
+		.name = "scl3300",
+		.avail_modes_table = scl3300_avail_modes_map,
+		.num_avail_modes = 3,
+		.chip_id = SCL3300_WHOAMI_ID,
+	},
 };
 
 DECLARE_CRC8_TABLE(sca3300_crc_table);
@@ -560,6 +583,7 @@ static int sca3300_probe(struct spi_device *spi)
 
 static const struct of_device_id sca3300_dt_ids[] = {
 	{ .compatible = "murata,sca3300"},
+	{ .compatible = "murata,scl3300"},
 	{}
 };
 MODULE_DEVICE_TABLE(of, sca3300_dt_ids);
-- 
2.25.1

[PATCH V6 5/5] iio: accel: sca3300: Add inclination channels

[LI Qingwu]

Different from SCA3300, SCL3300 can output inclination angles.
Angles are formed from acceleration with following equations:
ANG_X = atan2(accx , sqrt(pow(accy , 2) + pow(accz , 2)))
ANG_Y = atan2(accy , sqrt(pow(accx , 2) + pow(accz , 2)))
ANG_Z = atan2(accz , sqrt(pow(accx , 2) + pow(accy , 2)))

The commit adds the output of the raw value, scale
and scale_available of angles.

New interfaces:
  in_incli_scale
  in_incli_scale_available
  in_incli_x_raw
  in_incli_y_raw
  in_incli_z_raw
Data converted by application of scale to degrees.

Signed-off-by: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>
---
 drivers/iio/accel/sca3300.c | 82 +++++++++++++++++++++++++++++++++++--
 1 file changed, 79 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/accel/sca3300.c b/drivers/iio/accel/sca3300.c
index 3dcb4296fad2..7060eba360ae 100644
--- a/drivers/iio/accel/sca3300.c
+++ b/drivers/iio/accel/sca3300.c
@@ -44,12 +44,18 @@
 #define SCA3300_VALUE_RS_ERROR	0x3
 #define SCA3300_MASK_RS_STATUS	GENMASK(1, 0)
 
+#define SCA3300_REG_ANG_CTRL 0x0C
+#define SCA3300_ANG_ENABLE   0x1F
+
 enum sca3300_scan_indexes {
 	SCA3300_ACC_X = 0,
 	SCA3300_ACC_Y,
 	SCA3300_ACC_Z,
 	SCA3300_TEMP,
 	SCA3300_TIMESTAMP,
+	SCA3300_INCLI_X,
+	SCA3300_INCLI_Y,
+	SCA3300_INCLI_Z,
 };
 
 #define SCA3300_ACCEL_CHANNEL(index, reg, axis) {			\
@@ -73,6 +79,24 @@ enum sca3300_scan_indexes {
 	},								\
 }
 
+#define SCA3300_INCLI_CHANNEL(index, reg, axis) {			\
+	.type = IIO_INCLI,						\
+	.address = reg,							\
+	.modified = 1,							\
+	.channel2 = IIO_MOD_##axis,					\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),		\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),			\
+	.info_mask_shared_by_type_available =				\
+	BIT(IIO_CHAN_INFO_SCALE),					\
+	.scan_index = index,						\
+	.scan_type = {							\
+		.sign = 's',						\
+		.realbits = 16,						\
+		.storagebits = 16,					\
+		.endianness = IIO_CPU,					\
+	},								\
+}
+
 #define SCA3300_TEMP_CHANNEL(index, reg) {				\
 		.type = IIO_TEMP,					\
 		.address = reg,						\
@@ -106,15 +130,36 @@ static const int sca3300_accel_scale_map[] = {0, 1, 2, 2};
 static const int scl3300_accel_scale[][2] = {{0, 167}, {0, 333}, {0, 83}};
 static const int scl3300_accel_scale_map[] = {0, 1, 2};
 
+static const int scl3300_incli_scale[][2] = {{0, 5495}};
+static const int scl3300_incli_scale_map[] = {0, 0, 0};
+
 static const int sca3300_avail_modes_map[] = {0, 1, 2, 3};
 static const int scl3300_avail_modes_map[] = {0, 1, 3};
 
+static const struct iio_chan_spec scl3300_channels[] = {
+	SCA3300_ACCEL_CHANNEL(SCA3300_ACC_X, 0x1, X),
+	SCA3300_ACCEL_CHANNEL(SCA3300_ACC_Y, 0x2, Y),
+	SCA3300_ACCEL_CHANNEL(SCA3300_ACC_Z, 0x3, Z),
+	SCA3300_TEMP_CHANNEL(SCA3300_TEMP, 0x05),
+	IIO_CHAN_SOFT_TIMESTAMP(SCA3300_TIMESTAMP),
+	SCA3300_INCLI_CHANNEL(SCA3300_INCLI_X, 0x09, X),
+	SCA3300_INCLI_CHANNEL(SCA3300_INCLI_Y, 0x0A, Y),
+	SCA3300_INCLI_CHANNEL(SCA3300_INCLI_Z, 0x0B, Z),
+};
+
 static const unsigned long sca3300_scan_masks[] = {
 	BIT(SCA3300_ACC_X) | BIT(SCA3300_ACC_Y) | BIT(SCA3300_ACC_Z) |
 	BIT(SCA3300_TEMP),
 	0
 };
 
+static const unsigned long scl3300_scan_masks[] = {
+	BIT(SCA3300_ACC_X) | BIT(SCA3300_ACC_Y) | BIT(SCA3300_ACC_Z) |
+	BIT(SCA3300_TEMP) |
+	BIT(SCA3300_INCLI_X) | BIT(SCA3300_INCLI_Y) | BIT(SCA3300_INCLI_Z),
+	0
+};
+
 struct sca3300_chip_info {
 	const char *name;
 	const unsigned long *scan_masks;
@@ -123,14 +168,19 @@ struct sca3300_chip_info {
 	u8 num_accel_scales;
 	const int (*accel_scale)[2];
 	const int *accel_scale_map;
+	const int (*incli_scale)[2];
+	const int *incli_scale_map;
+	u8 num_incli_scales;
 	u8 num_freqs;
 	const int *freq_table;
 	const int *freq_map;
 	const int *avail_modes_table;
 	u8 num_avail_modes;
 	u8 chip_id;
+	bool angle;
 };
 
+
 /**
  * struct sca3300_data - device data
  * @spi: SPI device structure
@@ -160,19 +210,27 @@ static const struct sca3300_chip_info sca3300_chip_tbl[] = {
 		.num_accel_scales = ARRAY_SIZE(sca3300_accel_scale)*2,
 		.accel_scale = sca3300_accel_scale,
 		.accel_scale_map = sca3300_accel_scale_map,
+		.incli_scale = NULL,
+		.incli_scale_map = NULL,
+		.num_incli_scales = 0,
 		.num_freqs = ARRAY_SIZE(sca3300_lp_freq),
 		.freq_table = sca3300_lp_freq,
 		.freq_map = sca3300_lp_freq_map,
 		.avail_modes_table = sca3300_avail_modes_map,
 		.num_avail_modes = 4,
 		.chip_id = SCA3300_WHOAMI_ID,
+		.angle = false,
 	},
-	{	.scan_masks = sca3300_scan_masks,
-		.channels = sca3300_channels,
-		.num_channels = ARRAY_SIZE(sca3300_channels),
+	{
+		.scan_masks = scl3300_scan_masks,
+		.channels = scl3300_channels,
+		.num_channels = ARRAY_SIZE(scl3300_channels),
 		.num_accel_scales = ARRAY_SIZE(scl3300_accel_scale)*2,
 		.accel_scale = scl3300_accel_scale,
 		.accel_scale_map = scl3300_accel_scale_map,
+		.incli_scale = scl3300_incli_scale,
+		.incli_scale_map = scl3300_incli_scale_map,
+		.num_incli_scales =  ARRAY_SIZE(scl3300_incli_scale)*2,
 		.num_freqs = ARRAY_SIZE(scl3300_lp_freq),
 		.freq_table = scl3300_lp_freq,
 		.freq_map = scl3300_lp_freq_map,
@@ -180,6 +238,7 @@ static const struct sca3300_chip_info sca3300_chip_tbl[] = {
 		.avail_modes_table = scl3300_avail_modes_map,
 		.num_avail_modes = 3,
 		.chip_id = SCL3300_WHOAMI_ID,
+		.angle = true,
 	},
 };
 
@@ -387,6 +446,11 @@ static int sca3300_read_raw(struct iio_dev *indio_dev,
 		if (ret)
 			return ret;
 		switch (chan->type) {
+		case IIO_INCLI:
+			index = data->chip->incli_scale_map[index];
+			*val = data->chip->incli_scale[index][0];
+			*val2 = data->chip->incli_scale[index][1];
+			return IIO_VAL_INT_PLUS_MICRO;
 		case IIO_ACCEL:
 			index = data->chip->accel_scale_map[index];
 			*val = data->chip->accel_scale[index][0];
@@ -473,6 +537,13 @@ static int sca3300_init(struct sca3300_data *sca_data,
 
 	sca_data->chip = &sca3300_chip_tbl[i];
 
+	if (sca_data->chip->angle) {
+		ret = sca3300_write_reg(sca_data, SCA3300_REG_ANG_CTRL,
+					SCA3300_ANG_ENABLE);
+		if (ret)
+			return ret;
+	}
+
 	return 0;
 }
 
@@ -508,6 +579,11 @@ static int sca3300_read_avail(struct iio_dev *indio_dev,
 	switch (mask) {
 	case IIO_CHAN_INFO_SCALE:
 		switch (chan->type) {
+		case IIO_INCLI:
+			*vals = (const int *)data->chip->incli_scale;
+			*length = data->chip->num_incli_scales;
+			*type = IIO_VAL_INT_PLUS_MICRO;
+			return IIO_AVAIL_LIST;
 		case IIO_ACCEL:
 			*vals = (const int *)data->chip->accel_scale;
 			*length = data->chip->num_accel_scales;
-- 
2.25.1

Re: [PATCH V6 5/5] iio: accel: sca3300: Add inclination channels

[Tomas Melin]

Hi Li,

A few comments below.

On 13/05/2022 15:41, LI Qingwu wrote:
> Different from SCA3300, SCL3300 can output inclination angles.
> Angles are formed from acceleration with following equations:
> ANG_X = atan2(accx , sqrt(pow(accy , 2) + pow(accz , 2)))
> ANG_Y = atan2(accy , sqrt(pow(accx , 2) + pow(accz , 2)))
> ANG_Z = atan2(accz , sqrt(pow(accx , 2) + pow(accy , 2)))
> 
> The commit adds the output of the raw value, scale
> and scale_available of angles.
> 
> New interfaces:
>   in_incli_scale
>   in_incli_scale_available
>   in_incli_x_raw
>   in_incli_y_raw
>   in_incli_z_raw
> Data converted by application of scale to degrees.
> 
> Signed-off-by: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>
> ---
>  drivers/iio/accel/sca3300.c | 82 +++++++++++++++++++++++++++++++++++--
>  1 file changed, 79 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/iio/accel/sca3300.c b/drivers/iio/accel/sca3300.c
> index 3dcb4296fad2..7060eba360ae 100644
> --- a/drivers/iio/accel/sca3300.c
> +++ b/drivers/iio/accel/sca3300.c
> @@ -44,12 +44,18 @@
>  #define SCA3300_VALUE_RS_ERROR	0x3
>  #define SCA3300_MASK_RS_STATUS	GENMASK(1, 0)
>  
> +#define SCA3300_REG_ANG_CTRL 0x0C
> +#define SCA3300_ANG_ENABLE   0x1F
Since these are not available for SCA3300 I suggest using
SCL3300 prefix here. Also note that the other groups have
a comment block in place.


> +
>  enum sca3300_scan_indexes {
>  	SCA3300_ACC_X = 0,
>  	SCA3300_ACC_Y,
>  	SCA3300_ACC_Z,
>  	SCA3300_TEMP,
>  	SCA3300_TIMESTAMP,
> +	SCA3300_INCLI_X,
> +	SCA3300_INCLI_Y,
> +	SCA3300_INCLI_Z,
>  };
>  
>  #define SCA3300_ACCEL_CHANNEL(index, reg, axis) {			\
> @@ -73,6 +79,24 @@ enum sca3300_scan_indexes {
>  	},								\
>  }
>  
> +#define SCA3300_INCLI_CHANNEL(index, reg, axis) {			\
> +	.type = IIO_INCLI,						\
> +	.address = reg,							\
> +	.modified = 1,							\
> +	.channel2 = IIO_MOD_##axis,					\
> +	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),		\
> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),			\
> +	.info_mask_shared_by_type_available =				\
> +	BIT(IIO_CHAN_INFO_SCALE),					\
> +	.scan_index = index,						\
> +	.scan_type = {							\
> +		.sign = 's',						\
> +		.realbits = 16,						\
> +		.storagebits = 16,					\
> +		.endianness = IIO_CPU,					\
> +	},								\
> +}
> +
>  #define SCA3300_TEMP_CHANNEL(index, reg) {				\
>  		.type = IIO_TEMP,					\
>  		.address = reg,						\
> @@ -106,15 +130,36 @@ static const int sca3300_accel_scale_map[] = {0, 1, 2, 2};
>  static const int scl3300_accel_scale[][2] = {{0, 167}, {0, 333}, {0, 83}};
>  static const int scl3300_accel_scale_map[] = {0, 1, 2};
>  
> +static const int scl3300_incli_scale[][2] = {{0, 5495}};
> +static const int scl3300_incli_scale_map[] = {0, 0, 0};
> +
>  static const int sca3300_avail_modes_map[] = {0, 1, 2, 3};
>  static const int scl3300_avail_modes_map[] = {0, 1, 3};
>  
> +static const struct iio_chan_spec scl3300_channels[] = {
> +	SCA3300_ACCEL_CHANNEL(SCA3300_ACC_X, 0x1, X),
> +	SCA3300_ACCEL_CHANNEL(SCA3300_ACC_Y, 0x2, Y),
> +	SCA3300_ACCEL_CHANNEL(SCA3300_ACC_Z, 0x3, Z),
> +	SCA3300_TEMP_CHANNEL(SCA3300_TEMP, 0x05),
> +	IIO_CHAN_SOFT_TIMESTAMP(SCA3300_TIMESTAMP),

This happens to match with 0x4 in enum, but would be better to instead
use direct reference 0x4 here to not mix enum with channel ref?

> +	SCA3300_INCLI_CHANNEL(SCA3300_INCLI_X, 0x09, X),
> +	SCA3300_INCLI_CHANNEL(SCA3300_INCLI_Y, 0x0A, Y),
> +	SCA3300_INCLI_CHANNEL(SCA3300_INCLI_Z, 0x0B, Z),
> +};
> +
>  static const unsigned long sca3300_scan_masks[] = {
>  	BIT(SCA3300_ACC_X) | BIT(SCA3300_ACC_Y) | BIT(SCA3300_ACC_Z) |
>  	BIT(SCA3300_TEMP),
>  	0
>  };
>  
> +static const unsigned long scl3300_scan_masks[] = {
> +	BIT(SCA3300_ACC_X) | BIT(SCA3300_ACC_Y) | BIT(SCA3300_ACC_Z) |
> +	BIT(SCA3300_TEMP) |
> +	BIT(SCA3300_INCLI_X) | BIT(SCA3300_INCLI_Y) | BIT(SCA3300_INCLI_Z),
> +	0
> +};
> +
>  struct sca3300_chip_info {
>  	const char *name;
>  	const unsigned long *scan_masks;
> @@ -123,14 +168,19 @@ struct sca3300_chip_info {
>  	u8 num_accel_scales;
>  	const int (*accel_scale)[2];
>  	const int *accel_scale_map;
> +	const int (*incli_scale)[2];
> +	const int *incli_scale_map;
> +	u8 num_incli_scales;
>  	u8 num_freqs;
>  	const int *freq_table;
>  	const int *freq_map;
>  	const int *avail_modes_table;
>  	u8 num_avail_modes;
>  	u8 chip_id;
> +	bool angle;
Suggest removing this variable, see below.
>  };
>  
> +
>  /**
>   * struct sca3300_data - device data
>   * @spi: SPI device structure
> @@ -160,19 +210,27 @@ static const struct sca3300_chip_info sca3300_chip_tbl[] = {
>  		.num_accel_scales = ARRAY_SIZE(sca3300_accel_scale)*2,
>  		.accel_scale = sca3300_accel_scale,
>  		.accel_scale_map = sca3300_accel_scale_map,
> +		.incli_scale = NULL,
> +		.incli_scale_map = NULL,
> +		.num_incli_scales = 0,
I suppose these are redundant lines, can be removed?

>  		.num_freqs = ARRAY_SIZE(sca3300_lp_freq),
>  		.freq_table = sca3300_lp_freq,
>  		.freq_map = sca3300_lp_freq_map,
>  		.avail_modes_table = sca3300_avail_modes_map,
>  		.num_avail_modes = 4,
>  		.chip_id = SCA3300_WHOAMI_ID,
> +		.angle = false,
>  	},
> -	{	.scan_masks = sca3300_scan_masks,
> -		.channels = sca3300_channels,
> -		.num_channels = ARRAY_SIZE(sca3300_channels),
> +	{
> +		.scan_masks = scl3300_scan_masks,
> +		.channels = scl3300_channels,
> +		.num_channels = ARRAY_SIZE(scl3300_channels),
>  		.num_accel_scales = ARRAY_SIZE(scl3300_accel_scale)*2,
>  		.accel_scale = scl3300_accel_scale,
>  		.accel_scale_map = scl3300_accel_scale_map,
> +		.incli_scale = scl3300_incli_scale,
> +		.incli_scale_map = scl3300_incli_scale_map,
> +		.num_incli_scales =  ARRAY_SIZE(scl3300_incli_scale)*2,
>  		.num_freqs = ARRAY_SIZE(scl3300_lp_freq),
>  		.freq_table = scl3300_lp_freq,
>  		.freq_map = scl3300_lp_freq_map,
> @@ -180,6 +238,7 @@ static const struct sca3300_chip_info sca3300_chip_tbl[] = {
>  		.avail_modes_table = scl3300_avail_modes_map,
>  		.num_avail_modes = 3,
>  		.chip_id = SCL3300_WHOAMI_ID,
> +		.angle = true,
>  	},
>  };
>  
> @@ -387,6 +446,11 @@ static int sca3300_read_raw(struct iio_dev *indio_dev,
>  		if (ret)
>  			return ret;
>  		switch (chan->type) {
> +		case IIO_INCLI:
> +			index = data->chip->incli_scale_map[index];
> +			*val = data->chip->incli_scale[index][0];
> +			*val2 = data->chip->incli_scale[index][1];
> +			return IIO_VAL_INT_PLUS_MICRO;
>  		case IIO_ACCEL:
>  			index = data->chip->accel_scale_map[index];
>  			*val = data->chip->accel_scale[index][0];

Please check function comment for sca3300_init, it has references to
data sheet which should now be updated, too.

Check also startup delay after sw reset. For scl3300 is seems to be 25ms
instead of 15ms for sca3300, so that could also be updated to be 26ms in
order to safely support both chips and be in line with data sheet.

> @@ -473,6 +537,13 @@ static int sca3300_init(struct sca3300_data *sca_data,
>  
>  	sca_data->chip = &sca3300_chip_tbl[i];
>  
> +	if (sca_data->chip->angle) {
Instead of resorting to additional variable, can the difference scl/sca
be handled here like?
    if (value == SCL3300_WHOAMI_ID)

(assuming there are not many more chip variants to be handled here, this
would keep it somewhat more simple)

Thanks,
Tomas



> +		ret = sca3300_write_reg(sca_data, SCA3300_REG_ANG_CTRL,
> +					SCA3300_ANG_ENABLE);
> +		if (ret)
> +			return ret;
> +	}
> +
>  	return 0;
>  }
>  
> @@ -508,6 +579,11 @@ static int sca3300_read_avail(struct iio_dev *indio_dev,
>  	switch (mask) {
>  	case IIO_CHAN_INFO_SCALE:
>  		switch (chan->type) {
> +		case IIO_INCLI:
> +			*vals = (const int *)data->chip->incli_scale;
> +			*length = data->chip->num_incli_scales;
> +			*type = IIO_VAL_INT_PLUS_MICRO;
> +			return IIO_AVAIL_LIST;
>  		case IIO_ACCEL:
>  			*vals = (const int *)data->chip->accel_scale;
>  			*length = data->chip->num_accel_scales;