Hi,
this is looking quite good now. A few small comments below still.
On 23/05/2022 09:23, LI Qingwu 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@xxxxxxxxxxxxxxxxxxxxxxx>
> ---
> drivers/iio/accel/sca3300.c | 198 ++++++++++++++++++++++++++++--------
> 1 file changed, 157 insertions(+), 41 deletions(-)
>
> diff --git a/drivers/iio/accel/sca3300.c b/drivers/iio/accel/sca3300.c
> index ff16d2cc8c70..6463d12a9ab9 100644
> --- a/drivers/iio/accel/sca3300.c
> +++ b/drivers/iio/accel/sca3300.c
> @@ -93,19 +93,40 @@ 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
> * @lock: Data buffer lock
> + * @chip: Sensor chip specific information
> * @scan: Triggered buffer. Four channel 16-bit data + 64-bit timestamp
> * @txbuf: Transmit buffer
> * @rxbuf: Receive buffer
> @@ -113,6 +134,7 @@ static const unsigned long sca3300_scan_masks[] = {
> struct sca3300_data {
> struct spi_device *spi;
> struct mutex lock;
> + const struct sca3300_chip_info *chip;
> struct {
> s16 channels[4];
> s64 ts __aligned(sizeof(s64));
> @@ -121,6 +143,24 @@ struct sca3300_data {
> 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 +267,92 @@ 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, ®_val);
> + if (ret)
> + return ret;
> +
> + reg_val &= GENMASK(1, 0);
This silently assumes that mode register has always max 4 modes, yet
there is a parameter for this in chip_info (num_avail_modes).
Wondering why this masking was added, I cannot see mention about this in
datasheet that register REG_MODE would contain other bits that the
actual mode number.
Was there some specific case in mind for adding this masking?
> + 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;
> + int *opmode_scale;
> + int *new_scale;
> + unsigned int i;
> +
> + if (sca3300_get_op_mode(data, &index))
> + return -EINVAL;
Suggest not hiding return code from get_op_mode() here, instead use
ret = sca3300_get_op_mode(data, &index)
if (ret)
return ret;
Thanks,
Tomas
> +
> + /*
> + * Find a mode in which the requested sampling frequency is available
> + * and the scaling currently set is retained.
> + */
> + opmode_scale = (int *)chip->accel_scale[chip->accel_scale_map[index]];
> + for (i = 0; i < chip->num_avail_modes; i++) {
> + new_scale = (int *)chip->accel_scale[chip->accel_scale_map[i]];
> + if ((val == chip->freq_table[chip->freq_map[i]]) &&
> + (opmode_scale[1] == new_scale[1]) &&
> + (opmode_scale[0] == new_scale[0]))
> + 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);
> + /*
> + * 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.
> + */
> + 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, ®_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 +363,8 @@ 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 +373,24 @@ 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, ®_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, ®_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 +434,7 @@ 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 +451,17 @@ 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 +493,21 @@ 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 +539,6 @@ 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 +546,12 @@ 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);
