iio:st_pressure:initial lps22hb sensor support

Initial support for ST LPS22HB pressure sensor. Datasheet:
http://www2.st.com/resource/en/datasheet/lps22hb.pdf

Features:
* pressure data and timestamping channels
* sampling frequency selection
* interrupt based trigger
* over I2C or SPI

Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Documentation/devicetree/bindings/iio/st-sensors.txt

@@ -64,3 +64,4 @@ Pressure sensors:
 - st,lps001wp-press
 - st,lps25h-press
 - st,lps331ap-press
+- st,lps22hb-press

drivers/iio/pressure/Kconfig

@@ -131,7 +131,7 @@ config IIO_ST_PRESS
 	select IIO_TRIGGERED_BUFFER if (IIO_BUFFER)
 	help
 	  Say yes here to build support for STMicroelectronics pressure
-	  sensors: LPS001WP, LPS25H, LPS331AP.
+	  sensors: LPS001WP, LPS25H, LPS331AP, LPS22HB.
 
 	  This driver can also be built as a module. If so, these modules
 	  will be created:

drivers/iio/pressure/st_pressure.h

@@ -17,6 +17,7 @@
 #define LPS001WP_PRESS_DEV_NAME		"lps001wp"
 #define LPS25H_PRESS_DEV_NAME		"lps25h"
 #define LPS331AP_PRESS_DEV_NAME		"lps331ap"
+#define LPS22HB_PRESS_DEV_NAME		"lps22hb"
 
 /**
  * struct st_sensors_platform_data - default press platform data

drivers/iio/pressure/st_pressure_core.c

@@ -113,6 +113,26 @@
 #define ST_PRESS_LPS25H_OUT_XL_ADDR		0x28
 #define ST_TEMP_LPS25H_OUT_L_ADDR		0x2b
 
+/* CUSTOM VALUES FOR LPS22HB SENSOR */
+#define ST_PRESS_LPS22HB_WAI_EXP		0xb1
+#define ST_PRESS_LPS22HB_ODR_ADDR		0x10
+#define ST_PRESS_LPS22HB_ODR_MASK		0x70
+#define ST_PRESS_LPS22HB_ODR_AVL_1HZ_VAL	0x01
+#define ST_PRESS_LPS22HB_ODR_AVL_10HZ_VAL	0x02
+#define ST_PRESS_LPS22HB_ODR_AVL_25HZ_VAL	0x03
+#define ST_PRESS_LPS22HB_ODR_AVL_50HZ_VAL	0x04
+#define ST_PRESS_LPS22HB_ODR_AVL_75HZ_VAL	0x05
+#define ST_PRESS_LPS22HB_PW_ADDR		0x10
+#define ST_PRESS_LPS22HB_PW_MASK		0x70
+#define ST_PRESS_LPS22HB_BDU_ADDR		0x10
+#define ST_PRESS_LPS22HB_BDU_MASK		0x02
+#define ST_PRESS_LPS22HB_DRDY_IRQ_ADDR		0x12
+#define ST_PRESS_LPS22HB_DRDY_IRQ_INT1_MASK	0x04
+#define ST_PRESS_LPS22HB_DRDY_IRQ_INT2_MASK	0x08
+#define ST_PRESS_LPS22HB_IHL_IRQ_ADDR		0x12
+#define ST_PRESS_LPS22HB_IHL_IRQ_MASK		0x80
+#define ST_PRESS_LPS22HB_MULTIREAD_BIT		true
+
 static const struct iio_chan_spec st_press_1_channels[] = {
 	{
 		.type = IIO_PRESSURE,
@@ -183,6 +203,27 @@ static const struct iio_chan_spec st_press_lps001wp_channels[] = {
 	IIO_CHAN_SOFT_TIMESTAMP(1)
 };
 
+static const struct iio_chan_spec st_press_lps22hb_channels[] = {
+	{
+		.type = IIO_PRESSURE,
+		.channel2 = IIO_NO_MOD,
+		.address = ST_PRESS_1_OUT_XL_ADDR,
+		.scan_index = 0,
+		.scan_type = {
+			.sign = 'u',
+			.realbits = 24,
+			.storagebits = 24,
+			.endianness = IIO_LE,
+		},
+		.info_mask_separate =
+			BIT(IIO_CHAN_INFO_RAW) |
+			BIT(IIO_CHAN_INFO_SCALE),
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+		.modified = 0,
+	},
+	IIO_CHAN_SOFT_TIMESTAMP(1)
+};
+
 static const struct st_sensor_settings st_press_sensors_settings[] = {
 	{
 		.wai = ST_PRESS_LPS331AP_WAI_EXP,
@@ -326,6 +367,51 @@ static const struct st_sensor_settings st_press_sensors_settings[] = {
 		.multi_read_bit = ST_PRESS_LPS25H_MULTIREAD_BIT,
 		.bootime = 2,
 	},
+	{
+		.wai = ST_PRESS_LPS22HB_WAI_EXP,
+		.wai_addr = ST_SENSORS_DEFAULT_WAI_ADDRESS,
+		.sensors_supported = {
+			[0] = LPS22HB_PRESS_DEV_NAME,
+		},
+		.ch = (struct iio_chan_spec *)st_press_lps22hb_channels,
+		.num_ch = ARRAY_SIZE(st_press_lps22hb_channels),
+		.odr = {
+			.addr = ST_PRESS_LPS22HB_ODR_ADDR,
+			.mask = ST_PRESS_LPS22HB_ODR_MASK,
+			.odr_avl = {
+				{ 1, ST_PRESS_LPS22HB_ODR_AVL_1HZ_VAL, },
+				{ 10, ST_PRESS_LPS22HB_ODR_AVL_10HZ_VAL, },
+				{ 25, ST_PRESS_LPS22HB_ODR_AVL_25HZ_VAL, },
+				{ 50, ST_PRESS_LPS22HB_ODR_AVL_50HZ_VAL, },
+				{ 75, ST_PRESS_LPS22HB_ODR_AVL_75HZ_VAL, },
+			},
+		},
+		.pw = {
+			.addr = ST_PRESS_LPS22HB_PW_ADDR,
+			.mask = ST_PRESS_LPS22HB_PW_MASK,
+			.value_off = ST_SENSORS_DEFAULT_POWER_OFF_VALUE,
+		},
+		.fs = {
+			.fs_avl = {
+				[0] = {
+					.num = ST_PRESS_FS_AVL_1260MB,
+					.gain = ST_PRESS_KPASCAL_NANO_SCALE,
+				},
+			},
+		},
+		.bdu = {
+			.addr = ST_PRESS_LPS22HB_BDU_ADDR,
+			.mask = ST_PRESS_LPS22HB_BDU_MASK,
+		},
+		.drdy_irq = {
+			.addr = ST_PRESS_LPS22HB_DRDY_IRQ_ADDR,
+			.mask_int1 = ST_PRESS_LPS22HB_DRDY_IRQ_INT1_MASK,
+			.mask_int2 = ST_PRESS_LPS22HB_DRDY_IRQ_INT2_MASK,
+			.addr_ihl = ST_PRESS_LPS22HB_IHL_IRQ_ADDR,
+			.mask_ihl = ST_PRESS_LPS22HB_IHL_IRQ_MASK,
+		},
+		.multi_read_bit = ST_PRESS_LPS22HB_MULTIREAD_BIT,
+	},
 };
 
 static int st_press_write_raw(struct iio_dev *indio_dev,
@@ -454,7 +540,6 @@ int st_press_common_probe(struct iio_dev *indio_dev)
 	indio_dev->channels = press_data->sensor_settings->ch;
 	indio_dev->num_channels = press_data->sensor_settings->num_ch;
 
-	if (press_data->sensor_settings->fs.addr != 0)
 	press_data->current_fullscale =
 		(struct st_sensor_fullscale_avl *)
 			&press_data->sensor_settings->fs.fs_avl[0];

drivers/iio/pressure/st_pressure_i2c.c

@@ -32,6 +32,10 @@ static const struct of_device_id st_press_of_match[] = {
 		.compatible = "st,lps331ap-press",
 		.data = LPS331AP_PRESS_DEV_NAME,
 	},
+	{
+		.compatible = "st,lps22hb-press",
+		.data = LPS22HB_PRESS_DEV_NAME,
+	},
 	{},
 };
 MODULE_DEVICE_TABLE(of, st_press_of_match);

drivers/iio/pressure/st_pressure_spi.c

@@ -50,6 +50,7 @@ static const struct spi_device_id st_press_id_table[] = {
 	{ LPS001WP_PRESS_DEV_NAME },
 	{ LPS25H_PRESS_DEV_NAME },
 	{ LPS331AP_PRESS_DEV_NAME },
+	{ LPS22HB_PRESS_DEV_NAME },
 	{},
 };
 MODULE_DEVICE_TABLE(spi, st_press_id_table);