From: Tiberiu Breana Date: Wed, 24 Jun 2015 14:01:49 +0000 (+0300) Subject: iio: accel: Add sampling rate support for STK8312 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=5e913d27f91aa15e1311399385579bef5238e2cd;p=linux-beck.git iio: accel: Add sampling rate support for STK8312 Added support for setting the STK8312 accelerometer's sampling rate. Signed-off-by: Tiberiu Breana Signed-off-by: Jonathan Cameron --- diff --git a/drivers/iio/accel/stk8312.c b/drivers/iio/accel/stk8312.c index be58d66d5d33..c2bd1444d6da 100644 --- a/drivers/iio/accel/stk8312.c +++ b/drivers/iio/accel/stk8312.c @@ -29,6 +29,7 @@ #define STK8312_REG_ZOUT 0x02 #define STK8312_REG_INTSU 0x06 #define STK8312_REG_MODE 0x07 +#define STK8312_REG_SR 0x08 #define STK8312_REG_STH 0x13 #define STK8312_REG_RESET 0x20 #define STK8312_REG_AFECTRL 0x24 @@ -41,6 +42,8 @@ #define STK8312_DREADY_BIT 0x10 #define STK8312_INT_MODE 0xC0 #define STK8312_RNG_MASK 0xC0 +#define STK8312_SR_MASK 0x07 +#define STK8312_SR_400HZ_IDX 0 #define STK8312_RNG_SHIFT 6 #define STK8312_READ_RETRIES 16 #define STK8312_ALL_CHANNEL_MASK 7 @@ -65,20 +68,29 @@ static const int stk8312_scale_table[][2] = { {0, 461600}, {1, 231100} }; -#define STK8312_ACCEL_CHANNEL(index, reg, axis) { \ - .type = IIO_ACCEL, \ - .address = reg, \ - .modified = 1, \ - .channel2 = IIO_MOD_##axis, \ - .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ - .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ - .scan_index = index, \ - .scan_type = { \ - .sign = 's', \ - .realbits = 8, \ - .storagebits = 8, \ - .endianness = IIO_CPU, \ - }, \ +static const struct { + u16 val; + u32 val2; +} stk8312_samp_freq_table[] = { + {400, 0}, {200, 0}, {100, 0}, {50, 0}, {25, 0}, + {12, 500000}, {6, 250000}, {3, 125000} +}; + +#define STK8312_ACCEL_CHANNEL(index, reg, axis) { \ + .type = IIO_ACCEL, \ + .address = reg, \ + .modified = 1, \ + .channel2 = IIO_MOD_##axis, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ + BIT(IIO_CHAN_INFO_SAMP_FREQ), \ + .scan_index = index, \ + .scan_type = { \ + .sign = 's', \ + .realbits = 8, \ + .storagebits = 8, \ + .endianness = IIO_CPU, \ + }, \ } static const struct iio_chan_spec stk8312_channels[] = { @@ -92,6 +104,7 @@ struct stk8312_data { struct i2c_client *client; struct mutex lock; int range; + u8 sample_rate_idx; u8 mode; struct iio_trigger *dready_trig; bool dready_trigger_on; @@ -100,8 +113,11 @@ struct stk8312_data { static IIO_CONST_ATTR(in_accel_scale_available, STK8312_SCALE_AVAIL); +static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("3.125 6.25 12.5 25 50 100 200 400"); + static struct attribute *stk8312_attributes[] = { &iio_const_attr_in_accel_scale_available.dev_attr.attr, + &iio_const_attr_sampling_frequency_available.dev_attr.attr, NULL, }; @@ -220,6 +236,39 @@ static const struct iio_trigger_ops stk8312_trigger_ops = { .owner = THIS_MODULE, }; +static int stk8312_set_sample_rate(struct stk8312_data *data, int rate) +{ + int ret; + u8 masked_reg; + u8 mode; + struct i2c_client *client = data->client; + + if (rate == data->sample_rate_idx) + return 0; + + mode = data->mode; + /* We need to go in standby mode to modify registers */ + ret = stk8312_set_mode(data, STK8312_MODE_STANDBY); + if (ret < 0) + return ret; + + ret = i2c_smbus_read_byte_data(client, STK8312_REG_SR); + if (ret < 0) { + dev_err(&client->dev, "failed to set sampling rate\n"); + return ret; + } + + masked_reg = (ret & (~STK8312_SR_MASK)) | rate; + + ret = i2c_smbus_write_byte_data(client, STK8312_REG_SR, masked_reg); + if (ret < 0) + dev_err(&client->dev, "failed to set sampling rate\n"); + else + data->sample_rate_idx = rate; + + return stk8312_set_mode(data, mode); +} + static int stk8312_set_range(struct stk8312_data *data, u8 range) { int ret; @@ -303,6 +352,10 @@ static int stk8312_read_raw(struct iio_dev *indio_dev, *val = stk8312_scale_table[data->range - 1][0]; *val2 = stk8312_scale_table[data->range - 1][1]; return IIO_VAL_INT_PLUS_MICRO; + case IIO_CHAN_INFO_SAMP_FREQ: + *val = stk8312_samp_freq_table[data->sample_rate_idx].val; + *val2 = stk8312_samp_freq_table[data->sample_rate_idx].val2; + return IIO_VAL_INT_PLUS_MICRO; } return -EINVAL; @@ -332,6 +385,20 @@ static int stk8312_write_raw(struct iio_dev *indio_dev, ret = stk8312_set_range(data, index); mutex_unlock(&data->lock); + return ret; + case IIO_CHAN_INFO_SAMP_FREQ: + for (i = 0; i < ARRAY_SIZE(stk8312_samp_freq_table); i++) + if (val == stk8312_samp_freq_table[i].val && + val2 == stk8312_samp_freq_table[i].val2) { + index = i; + break; + } + if (index < 0) + return -EINVAL; + mutex_lock(&data->lock); + ret = stk8312_set_sample_rate(data, index); + mutex_unlock(&data->lock); + return ret; } @@ -479,6 +546,7 @@ static int stk8312_probe(struct i2c_client *client, dev_err(&client->dev, "failed to reset sensor\n"); return ret; } + data->sample_rate_idx = STK8312_SR_400HZ_IDX; ret = stk8312_set_range(data, 1); if (ret < 0) return ret;