iio: accel: sca3300: modified to support multi chips
authorLI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>
Sun, 29 May 2022 06:18:51 +0000 (06:18 +0000)
committerJonathan Cameron <Jonathan.Cameron@huawei.com>
Tue, 14 Jun 2022 10:53:09 +0000 (11:53 +0100)
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>
Reviewed-by: Tomas Melin <tomas.melin@vaisala.com>
Link: https://lore.kernel.org/r/20220529061853.3044893-4-Qing-wu.Li@leica-geosystems.com.cn
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
drivers/iio/accel/sca3300.c

index ff16d2c..21bf439 100644 (file)
@@ -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 +267,91 @@ 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;
+
+       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;
+
+       /*
+        * 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, &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 +362,8 @@ 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 +372,24 @@ 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, &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 +433,7 @@ 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 +450,17 @@ 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 +492,21 @@ 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 +538,6 @@ 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 +545,12 @@ 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);