Commit 5e913d27 authored by Tiberiu Breana's avatar Tiberiu Breana Committed by Jonathan Cameron
Browse files

iio: accel: Add sampling rate support for STK8312 



Added support for setting the STK8312 accelerometer's
sampling rate.

Signed-off-by: default avatarTiberiu Breana <tiberiu.a.breana@intel.com>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 95c12bba

drivers/iio/accel/stk8312.c

+82 −14
Original line number Diff line number Diff line
@@ -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
@@ -65,13 +68,22 @@ static const int stk8312_scale_table[][2] = { 
	{0, 461600}, {1, 231100}

};



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),	\

	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |		\

				    BIT(IIO_CHAN_INFO_SAMP_FREQ),	\

	.scan_index = index,						\

	.scan_type = {							\

		.sign = 's',						\
@@ -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;