iio: pressure: ms5611: add support for MS5607 temperature and pressure sensor

MS5607 is temperature and pressure sensor which hardware is similar to MS5611.
Both sensors share command protocol and support both I2C and SPI serial
protocols. They only differ in compensation algorithms.

Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 66 insertions, 10 deletions

diff --git a/drivers/iio/pressure/ms5611_core.c b/drivers/iio/pressure/ms5611_core.c
index 1109513cdda9..2f3d9b4aca4e 100644
--- a/drivers/iio/pressure/ms5611_core.c
+++ b/drivers/iio/pressure/ms5611_core.c
@@ -9,6 +9,7 @@
  *
  * Data sheet:
  *  http://www.meas-spec.com/downloads/MS5611-01BA03.pdf
+ *  http://www.meas-spec.com/downloads/MS5607-02BA03.pdf
  *
  */
 
@@ -50,7 +51,8 @@ static int ms5611_read_prom(struct iio_dev *indio_dev)
 	struct ms5611_state *st = iio_priv(indio_dev);
 
 	for (i = 0; i < MS5611_PROM_WORDS_NB; i++) {
-		ret = st->read_prom_word(&indio_dev->dev, i, &st->prom[i]);
+		ret = st->read_prom_word(&indio_dev->dev,
+					 i, &st->chip_info->prom[i]);
 		if (ret < 0) {
 			dev_err(&indio_dev->dev,
 				"failed to read prom at %d\n", i);
@@ -58,7 +60,7 @@ static int ms5611_read_prom(struct iio_dev *indio_dev)
 		}
 	}
 
-	if (!ms5611_prom_is_valid(st->prom, MS5611_PROM_WORDS_NB)) {
+	if (!ms5611_prom_is_valid(st->chip_info->prom, MS5611_PROM_WORDS_NB)) {
 		dev_err(&indio_dev->dev, "PROM integrity check failed\n");
 		return -ENODEV;
 	}
@@ -70,22 +72,30 @@ static int ms5611_read_temp_and_pressure(struct iio_dev *indio_dev,
 					 s32 *temp, s32 *pressure)
 {
 	int ret;
-	s32 t, p;
-	s64 off, sens, dt;
 	struct ms5611_state *st = iio_priv(indio_dev);
 
-	ret = st->read_adc_temp_and_pressure(&indio_dev->dev, &t, &p);
+	ret = st->read_adc_temp_and_pressure(&indio_dev->dev, temp, pressure);
 	if (ret < 0) {
 		dev_err(&indio_dev->dev,
 			"failed to read temperature and pressure\n");
 		return ret;
 	}
 
-	dt = t - (st->prom[5] << 8);
-	off = ((s64)st->prom[2] << 16) + ((st->prom[4] * dt) >> 7);
-	sens = ((s64)st->prom[1] << 15) + ((st->prom[3] * dt) >> 8);
+	return st->chip_info->temp_and_pressure_compensate(st->chip_info,
+							   temp, pressure);
+}
+
+static int ms5611_temp_and_pressure_compensate(struct ms5611_chip_info *chip_info,
+					       s32 *temp, s32 *pressure)
+{
+	s32 t = *temp, p = *pressure;
+	s64 off, sens, dt;
 
-	t = 2000 + ((st->prom[6] * dt) >> 23);
+	dt = t - (chip_info->prom[5] << 8);
+	off = ((s64)chip_info->prom[2] << 16) + ((chip_info->prom[4] * dt) >> 7);
+	sens = ((s64)chip_info->prom[1] << 15) + ((chip_info->prom[3] * dt) >> 8);
+
+	t = 2000 + ((chip_info->prom[6] * dt) >> 23);
 	if (t < 2000) {
 		s64 off2, sens2, t2;
 
@@ -111,6 +121,42 @@ static int ms5611_read_temp_and_pressure(struct iio_dev *indio_dev,
 	return 0;
 }
 
+static int ms5607_temp_and_pressure_compensate(struct ms5611_chip_info *chip_info,
+					       s32 *temp, s32 *pressure)
+{
+	s32 t = *temp, p = *pressure;
+	s64 off, sens, dt;
+
+	dt = t - (chip_info->prom[5] << 8);
+	off = ((s64)chip_info->prom[2] << 17) + ((chip_info->prom[4] * dt) >> 6);
+	sens = ((s64)chip_info->prom[1] << 16) + ((chip_info->prom[3] * dt) >> 7);
+
+	t = 2000 + ((chip_info->prom[6] * dt) >> 23);
+	if (t < 2000) {
+		s64 off2, sens2, t2;
+
+		t2 = (dt * dt) >> 31;
+		off2 = (61 * (t - 2000) * (t - 2000)) >> 4;
+		sens2 = off2 << 1;
+
+		if (t < -1500) {
+			s64 tmp = (t + 1500) * (t + 1500);
+
+			off2 += 15 * tmp;
+			sens2 += (8 * tmp);
+		}
+
+		t -= t2;
+		off -= off2;
+		sens -= sens2;
+	}
+
+	*temp = t;
+	*pressure = (((p * sens) >> 21) - off) >> 15;
+
+	return 0;
+}
+
 static int ms5611_reset(struct iio_dev *indio_dev)
 {
 	int ret;
@@ -160,6 +206,15 @@ static int ms5611_read_raw(struct iio_dev *indio_dev,
 	return -EINVAL;
 }
 
+static struct ms5611_chip_info chip_info_tbl[] = {
+	[MS5611] = {
+		.temp_and_pressure_compensate = ms5611_temp_and_pressure_compensate,
+	},
+	[MS5607] = {
+		.temp_and_pressure_compensate = ms5607_temp_and_pressure_compensate,
+	}
+};
+
 static const struct iio_chan_spec ms5611_channels[] = {
 	{
 		.type = IIO_PRESSURE,
@@ -187,12 +242,13 @@ static int ms5611_init(struct iio_dev *indio_dev)
 	return ms5611_read_prom(indio_dev);
 }
 
-int ms5611_probe(struct iio_dev *indio_dev, struct device *dev)
+int ms5611_probe(struct iio_dev *indio_dev, struct device *dev, int type)
 {
 	int ret;
 	struct ms5611_state *st = iio_priv(indio_dev);
 
 	mutex_init(&st->lock);
+	st->chip_info = &chip_info_tbl[type];
 	indio_dev->dev.parent = dev;
 	indio_dev->name = dev->driver->name;
 	indio_dev->info = &ms5611_info;