From 5dbbd19f11846574e9143ae96da8603017cf823b Mon Sep 17 00:00:00 2001 From: Martin Fuzzey Date: Mon, 1 Jun 2015 15:39:54 +0200 Subject: [PATCH] iio: mma8452: Add support for transient event debouncing Allow the debouce counter for transient events to be configured using the sysfs attribute events/in_accel_thresh_rising_period Signed-off-by: Martin Fuzzey Signed-off-by: Jonathan Cameron --- drivers/iio/accel/mma8452.c | 76 ++++++++++++++++++++++++++++++++++++++------- 1 file changed, 65 insertions(+), 11 deletions(-) diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c index f30eb9b7a99c..7429df3a191e 100644 --- a/drivers/iio/accel/mma8452.c +++ b/drivers/iio/accel/mma8452.c @@ -38,6 +38,7 @@ #define MMA8452_TRANSIENT_SRC_ZTRANSE BIT(5) #define MMA8452_TRANSIENT_THS 0x1f #define MMA8452_TRANSIENT_THS_MASK 0x7f +#define MMA8452_TRANSIENT_COUNT 0x20 #define MMA8452_OFF_X 0x2f #define MMA8452_OFF_Y 0x30 #define MMA8452_OFF_Z 0x31 @@ -124,6 +125,12 @@ static int mma8452_get_int_plus_micros_index(const int (*vals)[2], int n, return -EINVAL; } +static int mma8452_get_odr_index(struct mma8452_data *data) +{ + return (data->ctrl_reg1 & MMA8452_CTRL_DR_MASK) >> + MMA8452_CTRL_DR_SHIFT; +} + static const int mma8452_samp_freq[8][2] = { {800, 0}, {400, 0}, {200, 0}, {100, 0}, {50, 0}, {12, 500000}, {6, 250000}, {1, 560000} @@ -139,6 +146,18 @@ static const int mma8452_scales[3][2] = { {0, 9577}, {0, 19154}, {0, 38307} }; +/* Datasheet table 35 (step time vs sample frequency) */ +static const int mma8452_transient_time_step_us[8] = { + 1250, + 2500, + 5000, + 10000, + 20000, + 20000, + 20000, + 20000 +}; + static ssize_t mma8452_show_samp_freq_avail(struct device *dev, struct device_attribute *attr, char *buf) { @@ -198,8 +217,7 @@ static int mma8452_read_raw(struct iio_dev *indio_dev, *val2 = mma8452_scales[i][1]; return IIO_VAL_INT_PLUS_MICRO; case IIO_CHAN_INFO_SAMP_FREQ: - i = (data->ctrl_reg1 & MMA8452_CTRL_DR_MASK) >> - MMA8452_CTRL_DR_SHIFT; + i = mma8452_get_odr_index(data); *val = mma8452_samp_freq[i][0]; *val2 = mma8452_samp_freq[i][1]; return IIO_VAL_INT_PLUS_MICRO; @@ -297,15 +315,33 @@ static int mma8452_read_thresh(struct iio_dev *indio_dev, int *val, int *val2) { struct mma8452_data *data = iio_priv(indio_dev); - int ret; + int ret, us; - ret = i2c_smbus_read_byte_data(data->client, MMA8452_TRANSIENT_THS); - if (ret < 0) - return ret; + switch (info) { + case IIO_EV_INFO_VALUE: + ret = i2c_smbus_read_byte_data(data->client, + MMA8452_TRANSIENT_THS); + if (ret < 0) + return ret; + + *val = ret & MMA8452_TRANSIENT_THS_MASK; + return IIO_VAL_INT; - *val = ret & MMA8452_TRANSIENT_THS_MASK; + case IIO_EV_INFO_PERIOD: + ret = i2c_smbus_read_byte_data(data->client, + MMA8452_TRANSIENT_COUNT); + if (ret < 0) + return ret; + + us = ret * mma8452_transient_time_step_us[ + mma8452_get_odr_index(data)]; + *val = us / USEC_PER_SEC; + *val2 = us % USEC_PER_SEC; + return IIO_VAL_INT_PLUS_MICRO; - return IIO_VAL_INT; + default: + return -EINVAL; + } } static int mma8452_write_thresh(struct iio_dev *indio_dev, @@ -316,9 +352,26 @@ static int mma8452_write_thresh(struct iio_dev *indio_dev, int val, int val2) { struct mma8452_data *data = iio_priv(indio_dev); + int steps; - return mma8452_change_config(data, MMA8452_TRANSIENT_THS, - val & MMA8452_TRANSIENT_THS_MASK); + switch (info) { + case IIO_EV_INFO_VALUE: + return mma8452_change_config(data, MMA8452_TRANSIENT_THS, + val & MMA8452_TRANSIENT_THS_MASK); + + case IIO_EV_INFO_PERIOD: + steps = (val * USEC_PER_SEC + val2) / + mma8452_transient_time_step_us[ + mma8452_get_odr_index(data)]; + + if (steps > 0xff) + return -EINVAL; + + return mma8452_change_config(data, MMA8452_TRANSIENT_COUNT, + steps); + default: + return -EINVAL; + } } static int mma8452_read_event_config(struct iio_dev *indio_dev, @@ -456,7 +509,8 @@ static const struct iio_event_spec mma8452_transient_event[] = { .type = IIO_EV_TYPE_THRESH, .dir = IIO_EV_DIR_RISING, .mask_separate = BIT(IIO_EV_INFO_ENABLE), - .mask_shared_by_type = BIT(IIO_EV_INFO_VALUE) + .mask_shared_by_type = BIT(IIO_EV_INFO_VALUE) | + BIT(IIO_EV_INFO_PERIOD) }, }; -- 2.11.0