On Mon, 20 May 2019 21:13:34 -0500 Eddie James <[email protected]> wrote:
> The DPS310 supports measurement of pressure, so support that in the > driver. Use background measurement like the temperature sensing and > default to lowest precision and lowest measurement rate. > > Signed-off-by: Eddie James <[email protected]> > Acked-by: Jonathan Cameron <[email protected]> Applied to the togreg branch of iio.git and pushed out as testing for the autobuilders to play with it. Thanks, Jonathan > --- > drivers/iio/pressure/dps310.c | 363 > +++++++++++++++++++++++++++++++++++++++--- > 1 file changed, 337 insertions(+), 26 deletions(-) > > diff --git a/drivers/iio/pressure/dps310.c b/drivers/iio/pressure/dps310.c > index a093e3a..2c1943b 100644 > --- a/drivers/iio/pressure/dps310.c > +++ b/drivers/iio/pressure/dps310.c > @@ -11,11 +11,12 @@ > * c0 * 0.5 + c1 * T_raw / kT °C > * > * TODO: > - * - Pressure sensor readings > * - Optionally support the FIFO > */ > > #include <linux/i2c.h> > +#include <linux/limits.h> > +#include <linux/math64.h> > #include <linux/module.h> > #include <linux/regmap.h> > > @@ -31,6 +32,8 @@ > #define DPS310_TMP_B1 0x04 > #define DPS310_TMP_B2 0x05 > #define DPS310_PRS_CFG 0x06 > +#define DPS310_PRS_RATE_BITS GENMASK(6, 4) > +#define DPS310_PRS_PRC_BITS GENMASK(3, 0) > #define DPS310_TMP_CFG 0x07 > #define DPS310_TMP_RATE_BITS GENMASK(6, 4) > #define DPS310_TMP_PRC_BITS GENMASK(3, 0) > @@ -83,6 +86,8 @@ struct dps310_data { > struct mutex lock; /* Lock for sequential HW access functions */ > > s32 c0, c1; > + s32 c00, c10, c20, c30, c01, c11, c21; > + s32 pressure_raw; > s32 temp_raw; > }; > > @@ -93,33 +98,79 @@ struct dps310_data { > BIT(IIO_CHAN_INFO_SAMP_FREQ) | > BIT(IIO_CHAN_INFO_PROCESSED), > }, > + { > + .type = IIO_PRESSURE, > + .info_mask_separate = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO) | > + BIT(IIO_CHAN_INFO_SAMP_FREQ) | > + BIT(IIO_CHAN_INFO_PROCESSED), > + }, > }; > > /* To be called after checking the COEF_RDY bit in MEAS_CFG */ > -static int dps310_get_temp_coef(struct dps310_data *data) > +static int dps310_get_coefs(struct dps310_data *data) > { > int rc; > - u8 coef[3]; > + u8 coef[18]; > u32 c0, c1; > + u32 c00, c10, c20, c30, c01, c11, c21; > > - /* > - * Read temperature calibration coefficients c0 and c1 from the > - * COEF register. The numbers are 12-bit 2's compliment numbers > - */ > + /* Read all sensor calibration coefficients from the COEF registers. */ > rc = regmap_bulk_read(data->regmap, DPS310_COEF_BASE, coef, > sizeof(coef)); > if (rc < 0) > return rc; > > + /* > + * Calculate temperature calibration coefficients c0 and c1. The > + * numbers are 12-bit 2's complement numbers. > + */ > c0 = (coef[0] << 4) | (coef[1] >> 4); > data->c0 = sign_extend32(c0, 11); > > c1 = ((coef[1] & GENMASK(3, 0)) << 8) | coef[2]; > data->c1 = sign_extend32(c1, 11); > > + /* > + * Calculate pressure calibration coefficients. c00 and c10 are 20 bit > + * 2's complement numbers, while the rest are 16 bit 2's complement > + * numbers. > + */ > + c00 = (coef[3] << 12) | (coef[4] << 4) | (coef[5] >> 4); > + data->c00 = sign_extend32(c00, 19); > + > + c10 = ((coef[5] & GENMASK(3, 0)) << 16) | (coef[6] << 8) | coef[7]; > + data->c10 = sign_extend32(c10, 19); > + > + c01 = (coef[8] << 8) | coef[9]; > + data->c01 = sign_extend32(c01, 15); > + > + c11 = (coef[10] << 8) | coef[11]; > + data->c11 = sign_extend32(c11, 15); > + > + c20 = (coef[12] << 8) | coef[13]; > + data->c20 = sign_extend32(c20, 15); > + > + c21 = (coef[14] << 8) | coef[15]; > + data->c21 = sign_extend32(c21, 15); > + > + c30 = (coef[16] << 8) | coef[17]; > + data->c30 = sign_extend32(c30, 15); > + > return 0; > } > > +static int dps310_get_pres_precision(struct dps310_data *data) > +{ > + int rc; > + int val; > + > + rc = regmap_read(data->regmap, DPS310_PRS_CFG, &val); > + if (rc < 0) > + return rc; > + > + return BIT(val & GENMASK(2, 0)); > +} > + > static int dps310_get_temp_precision(struct dps310_data *data) > { > int rc; > @@ -137,6 +188,25 @@ static int dps310_get_temp_precision(struct dps310_data > *data) > } > > /* Called with lock held */ > +static int dps310_set_pres_precision(struct dps310_data *data, int val) > +{ > + int rc; > + u8 shift_en; > + > + if (val < 0 || val > 128) > + return -EINVAL; > + > + shift_en = val >= 16 ? DPS310_PRS_SHIFT_EN : 0; > + rc = regmap_write_bits(data->regmap, DPS310_CFG_REG, > + DPS310_PRS_SHIFT_EN, shift_en); > + if (rc) > + return rc; > + > + return regmap_update_bits(data->regmap, DPS310_PRS_CFG, > + DPS310_PRS_PRC_BITS, ilog2(val)); > +} > + > +/* Called with lock held */ > static int dps310_set_temp_precision(struct dps310_data *data, int val) > { > int rc; > @@ -156,6 +226,20 @@ static int dps310_set_temp_precision(struct dps310_data > *data, int val) > } > > /* Called with lock held */ > +static int dps310_set_pres_samp_freq(struct dps310_data *data, int freq) > +{ > + u8 val; > + > + if (freq < 0 || freq > 128) > + return -EINVAL; > + > + val = ilog2(freq) << 4; > + > + return regmap_update_bits(data->regmap, DPS310_PRS_CFG, > + DPS310_PRS_RATE_BITS, val); > +} > + > +/* Called with lock held */ > static int dps310_set_temp_samp_freq(struct dps310_data *data, int freq) > { > u8 val; > @@ -169,6 +253,18 @@ static int dps310_set_temp_samp_freq(struct dps310_data > *data, int freq) > DPS310_TMP_RATE_BITS, val); > } > > +static int dps310_get_pres_samp_freq(struct dps310_data *data) > +{ > + int rc; > + int val; > + > + rc = regmap_read(data->regmap, DPS310_PRS_CFG, &val); > + if (rc < 0) > + return rc; > + > + return BIT((val & DPS310_PRS_RATE_BITS) >> 4); > +} > + > static int dps310_get_temp_samp_freq(struct dps310_data *data) > { > int rc; > @@ -181,6 +277,16 @@ static int dps310_get_temp_samp_freq(struct dps310_data > *data) > return BIT((val & DPS310_TMP_RATE_BITS) >> 4); > } > > +static int dps310_get_pres_k(struct dps310_data *data) > +{ > + int rc = dps310_get_pres_precision(data); > + > + if (rc < 0) > + return rc; > + > + return scale_factors[ilog2(rc)]; > +} > + > static int dps310_get_temp_k(struct dps310_data *data) > { > int rc = dps310_get_temp_precision(data); > @@ -191,7 +297,7 @@ static int dps310_get_temp_k(struct dps310_data *data) > return scale_factors[ilog2(rc)]; > } > > -static int dps310_read_temp(struct dps310_data *data) > +static int dps310_read_pres_raw(struct dps310_data *data) > { > int rc; > int rate; > @@ -203,23 +309,67 @@ static int dps310_read_temp(struct dps310_data *data) > if (mutex_lock_interruptible(&data->lock)) > return -EINTR; > > - rate = dps310_get_temp_samp_freq(data); > + rate = dps310_get_pres_samp_freq(data); > timeout = DPS310_POLL_TIMEOUT_US(rate); > > /* Poll for sensor readiness; base the timeout upon the sample rate. */ > rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready, > - ready & DPS310_TMP_RDY, > + ready & DPS310_PRS_RDY, > DPS310_POLL_SLEEP_US(timeout), timeout); > + if (rc) > + goto done; > + > + rc = regmap_bulk_read(data->regmap, DPS310_PRS_BASE, val, sizeof(val)); > if (rc < 0) > goto done; > > + raw = (val[0] << 16) | (val[1] << 8) | val[2]; > + data->pressure_raw = sign_extend32(raw, 23); > + > +done: > + mutex_unlock(&data->lock); > + return rc; > +} > + > +/* Called with lock held */ > +static int dps310_read_temp_ready(struct dps310_data *data) > +{ > + int rc; > + u8 val[3]; > + s32 raw; > + > rc = regmap_bulk_read(data->regmap, DPS310_TMP_BASE, val, sizeof(val)); > if (rc < 0) > - goto done; > + return rc; > > raw = (val[0] << 16) | (val[1] << 8) | val[2]; > data->temp_raw = sign_extend32(raw, 23); > > + return 0; > +} > + > +static int dps310_read_temp_raw(struct dps310_data *data) > +{ > + int rc; > + int rate; > + int ready; > + int timeout; > + > + if (mutex_lock_interruptible(&data->lock)) > + return -EINTR; > + > + rate = dps310_get_temp_samp_freq(data); > + timeout = DPS310_POLL_TIMEOUT_US(rate); > + > + /* Poll for sensor readiness; base the timeout upon the sample rate. */ > + rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready, > + ready & DPS310_TMP_RDY, > + DPS310_POLL_SLEEP_US(timeout), timeout); > + if (rc < 0) > + goto done; > + > + rc = dps310_read_temp_ready(data); > + > done: > mutex_unlock(&data->lock); > return rc; > @@ -267,19 +417,40 @@ static int dps310_write_raw(struct iio_dev *iio, > int rc; > struct dps310_data *data = iio_priv(iio); > > - if (chan->type != IIO_TEMP) > - return -EINVAL; > - > if (mutex_lock_interruptible(&data->lock)) > return -EINTR; > > switch (mask) { > case IIO_CHAN_INFO_SAMP_FREQ: > - rc = dps310_set_temp_samp_freq(data, val); > + switch (chan->type) { > + case IIO_PRESSURE: > + rc = dps310_set_pres_samp_freq(data, val); > + break; > + > + case IIO_TEMP: > + rc = dps310_set_temp_samp_freq(data, val); > + break; > + > + default: > + rc = -EINVAL; > + break; > + } > break; > > case IIO_CHAN_INFO_OVERSAMPLING_RATIO: > - rc = dps310_set_temp_precision(data, val); > + switch (chan->type) { > + case IIO_PRESSURE: > + rc = dps310_set_pres_precision(data, val); > + break; > + > + case IIO_TEMP: > + rc = dps310_set_temp_precision(data, val); > + break; > + > + default: > + rc = -EINVAL; > + break; > + } > break; > > default: > @@ -291,6 +462,124 @@ static int dps310_write_raw(struct iio_dev *iio, > return rc; > } > > +static int dps310_calculate_pressure(struct dps310_data *data) > +{ > + int i; > + int rc; > + int t_ready; > + int kpi = dps310_get_pres_k(data); > + int kti = dps310_get_temp_k(data); > + s64 rem = 0ULL; > + s64 pressure = 0ULL; > + s64 p; > + s64 t; > + s64 denoms[7]; > + s64 nums[7]; > + s64 rems[7]; > + s64 kp; > + s64 kt; > + > + if (kpi < 0) > + return kpi; > + > + if (kti < 0) > + return kti; > + > + kp = (s64)kpi; > + kt = (s64)kti; > + > + /* Refresh temp if it's ready, otherwise just use the latest value */ > + if (mutex_trylock(&data->lock)) { > + rc = regmap_read(data->regmap, DPS310_MEAS_CFG, &t_ready); > + if (rc >= 0 && t_ready & DPS310_TMP_RDY) > + dps310_read_temp_ready(data); > + > + mutex_unlock(&data->lock); > + } > + > + p = (s64)data->pressure_raw; > + t = (s64)data->temp_raw; > + > + /* Section 4.9.1 of the DPS310 spec; algebra'd to avoid underflow */ > + nums[0] = (s64)data->c00; > + denoms[0] = 1LL; > + nums[1] = p * (s64)data->c10; > + denoms[1] = kp; > + nums[2] = p * p * (s64)data->c20; > + denoms[2] = kp * kp; > + nums[3] = p * p * p * (s64)data->c30; > + denoms[3] = kp * kp * kp; > + nums[4] = t * (s64)data->c01; > + denoms[4] = kt; > + nums[5] = t * p * (s64)data->c11; > + denoms[5] = kp * kt; > + nums[6] = t * p * p * (s64)data->c21; > + denoms[6] = kp * kp * kt; > + > + /* Kernel lacks a div64_s64_rem function; denoms are all positive */ > + for (i = 0; i < 7; ++i) { > + u64 irem; > + > + if (nums[i] < 0LL) { > + pressure -= div64_u64_rem(-nums[i], denoms[i], &irem); > + rems[i] = -irem; > + } else { > + pressure += div64_u64_rem(nums[i], denoms[i], &irem); > + rems[i] = (s64)irem; > + } > + } > + > + /* Increase precision and calculate the remainder sum */ > + for (i = 0; i < 7; ++i) > + rem += div64_s64((s64)rems[i] * 1000000000LL, denoms[i]); > + > + pressure += div_s64(rem, 1000000000LL); > + if (pressure < 0LL) > + return -ERANGE; > + > + return (int)min_t(s64, pressure, INT_MAX); > +} > + > +static int dps310_read_pressure(struct dps310_data *data, int *val, int > *val2, > + long mask) > +{ > + int rc; > + > + switch (mask) { > + case IIO_CHAN_INFO_SAMP_FREQ: > + rc = dps310_get_pres_samp_freq(data); > + if (rc < 0) > + return rc; > + > + *val = rc; > + return IIO_VAL_INT; > + > + case IIO_CHAN_INFO_PROCESSED: > + rc = dps310_read_pres_raw(data); > + if (rc) > + return rc; > + > + rc = dps310_calculate_pressure(data); > + if (rc < 0) > + return rc; > + > + *val = rc; > + *val2 = 1000; /* Convert Pa to KPa per IIO ABI */ > + return IIO_VAL_FRACTIONAL; > + > + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: > + rc = dps310_get_pres_precision(data); > + if (rc < 0) > + return rc; > + > + *val = rc; > + return IIO_VAL_INT; > + > + default: > + return -EINVAL; > + } > +} > + > static int dps310_calculate_temp(struct dps310_data *data) > { > s64 c0; > @@ -310,11 +599,9 @@ static int dps310_calculate_temp(struct dps310_data > *data) > return (int)div_s64(t * 1000LL, kt); > } > > -static int dps310_read_raw(struct iio_dev *iio, > - struct iio_chan_spec const *chan, > - int *val, int *val2, long mask) > +static int dps310_read_temp(struct dps310_data *data, int *val, int *val2, > + long mask) > { > - struct dps310_data *data = iio_priv(iio); > int rc; > > switch (mask) { > @@ -327,7 +614,7 @@ static int dps310_read_raw(struct iio_dev *iio, > return IIO_VAL_INT; > > case IIO_CHAN_INFO_PROCESSED: > - rc = dps310_read_temp(data); > + rc = dps310_read_temp_raw(data); > if (rc) > return rc; > > @@ -351,6 +638,24 @@ static int dps310_read_raw(struct iio_dev *iio, > } > } > > +static int dps310_read_raw(struct iio_dev *iio, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long mask) > +{ > + struct dps310_data *data = iio_priv(iio); > + > + switch (chan->type) { > + case IIO_PRESSURE: > + return dps310_read_pressure(data, val, val2, mask); > + > + case IIO_TEMP: > + return dps310_read_temp(data, val, val2, mask); > + > + default: > + return -EINVAL; > + } > +} > + > static void dps310_reset(void *action_data) > { > struct dps310_data *data = action_data; > @@ -444,6 +749,12 @@ static int dps310_probe(struct i2c_client *client, > return rc; > > /* > + * Set up pressure sensor in single sample, one measurement per second > + * mode > + */ > + rc = regmap_write(data->regmap, DPS310_PRS_CFG, 0); > + > + /* > * Set up external (MEMS) temperature sensor in single sample, one > * measurement per second mode > */ > @@ -451,9 +762,9 @@ static int dps310_probe(struct i2c_client *client, > if (rc < 0) > return rc; > > - /* Temp shift is disabled when PRC <= 8 */ > + /* Temp and pressure shifts are disabled when PRC <= 8 */ > rc = regmap_write_bits(data->regmap, DPS310_CFG_REG, > - DPS310_TMP_SHIFT_EN, 0); > + DPS310_PRS_SHIFT_EN | DPS310_TMP_SHIFT_EN, 0); > if (rc < 0) > return rc; > > @@ -463,9 +774,9 @@ static int dps310_probe(struct i2c_client *client, > if (rc < 0) > return rc; > > - /* Turn on temperature measurement in the background */ > + /* Turn on temperature and pressure measurement in the background */ > rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG, > - DPS310_MEAS_CTRL_BITS, > + DPS310_MEAS_CTRL_BITS, DPS310_PRS_EN | > DPS310_TEMP_EN | DPS310_BACKGROUND); > if (rc < 0) > return rc; > @@ -479,7 +790,7 @@ static int dps310_probe(struct i2c_client *client, > if (rc < 0) > return rc; > > - rc = dps310_get_temp_coef(data); > + rc = dps310_get_coefs(data); > if (rc < 0) > return rc; >
