iio: st_accel: support the LIS331DL sensor

This adds support for the LIS331DL sensor version. This is
a simple 8bit-only accelerometer.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

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

@@ -30,6 +30,7 @@ Accelerometers:
 - st,lsm330d-accel
 - st,lsm330dl-accel
 - st,lsm330dlc-accel
+- st,lis331dl-accel
 - st,lis331dlh-accel
 - st,lsm303dl-accel
 - st,lsm303dlm-accel

drivers/iio/accel/st_accel.h

@@ -20,6 +20,7 @@
 #define LSM330D_ACCEL_DEV_NAME		"lsm330d_accel"
 #define LSM330DL_ACCEL_DEV_NAME		"lsm330dl_accel"
 #define LSM330DLC_ACCEL_DEV_NAME	"lsm330dlc_accel"
+#define LIS331DL_ACCEL_DEV_NAME		"lis331dl_accel"
 #define LIS331DLH_ACCEL_DEV_NAME	"lis331dlh"
 #define LSM303DL_ACCEL_DEV_NAME		"lsm303dl_accel"
 #define LSM303DLH_ACCEL_DEV_NAME	"lsm303dlh_accel"

drivers/iio/accel/st_accel_core.c

@@ -153,6 +153,28 @@
 #define ST_ACCEL_4_IG1_EN_MASK			0x08
 #define ST_ACCEL_4_MULTIREAD_BIT		true
 
+/* CUSTOM VALUES FOR SENSOR 5 */
+#define ST_ACCEL_5_WAI_EXP			0x3b
+#define ST_ACCEL_5_ODR_ADDR			0x20
+#define ST_ACCEL_5_ODR_MASK			0x80
+#define ST_ACCEL_5_ODR_AVL_100HZ_VAL		0x00
+#define ST_ACCEL_5_ODR_AVL_400HZ_VAL		0x01
+#define ST_ACCEL_5_PW_ADDR			0x20
+#define ST_ACCEL_5_PW_MASK			0x40
+#define ST_ACCEL_5_FS_ADDR			0x20
+#define ST_ACCEL_5_FS_MASK			0x20
+#define ST_ACCEL_5_FS_AVL_2_VAL			0X00
+#define ST_ACCEL_5_FS_AVL_8_VAL			0X01
+/* TODO: check these resulting gain settings, these are not in the datsheet */
+#define ST_ACCEL_5_FS_AVL_2_GAIN		IIO_G_TO_M_S_2(18000)
+#define ST_ACCEL_5_FS_AVL_8_GAIN		IIO_G_TO_M_S_2(72000)
+#define ST_ACCEL_5_DRDY_IRQ_ADDR		0x22
+#define ST_ACCEL_5_DRDY_IRQ_INT1_MASK		0x04
+#define ST_ACCEL_5_DRDY_IRQ_INT2_MASK		0x20
+#define ST_ACCEL_5_IG1_EN_ADDR			0x21
+#define ST_ACCEL_5_IG1_EN_MASK			0x08
+#define ST_ACCEL_5_MULTIREAD_BIT		false
+
 static const struct iio_chan_spec st_accel_8bit_channels[] = {
 	ST_SENSORS_LSM_CHANNELS(IIO_ACCEL,
 			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
@@ -470,6 +492,54 @@ static const struct st_sensor_settings st_accel_sensors_settings[] = {
 		.multi_read_bit = ST_ACCEL_4_MULTIREAD_BIT,
 		.bootime = 2, /* guess */
 	},
+	{
+		.wai = ST_ACCEL_5_WAI_EXP,
+		.sensors_supported = {
+			[0] = LIS331DL_ACCEL_DEV_NAME,
+		},
+		.ch = (struct iio_chan_spec *)st_accel_8bit_channels,
+		.odr = {
+			.addr = ST_ACCEL_5_ODR_ADDR,
+			.mask = ST_ACCEL_5_ODR_MASK,
+			.odr_avl = {
+				{ 100, ST_ACCEL_5_ODR_AVL_100HZ_VAL },
+				{ 400, ST_ACCEL_5_ODR_AVL_400HZ_VAL, },
+			},
+		},
+		.pw = {
+			.addr = ST_ACCEL_5_PW_ADDR,
+			.mask = ST_ACCEL_5_PW_MASK,
+			.value_on = ST_SENSORS_DEFAULT_POWER_ON_VALUE,
+			.value_off = ST_SENSORS_DEFAULT_POWER_OFF_VALUE,
+		},
+		.enable_axis = {
+			.addr = ST_SENSORS_DEFAULT_AXIS_ADDR,
+			.mask = ST_SENSORS_DEFAULT_AXIS_MASK,
+		},
+		.fs = {
+			.addr = ST_ACCEL_5_FS_ADDR,
+			.mask = ST_ACCEL_5_FS_MASK,
+			.fs_avl = {
+				[0] = {
+					.num = ST_ACCEL_FS_AVL_2G,
+					.value = ST_ACCEL_5_FS_AVL_2_VAL,
+					.gain = ST_ACCEL_5_FS_AVL_2_GAIN,
+				},
+				[1] = {
+					.num = ST_ACCEL_FS_AVL_8G,
+					.value = ST_ACCEL_5_FS_AVL_8_VAL,
+					.gain = ST_ACCEL_5_FS_AVL_8_GAIN,
+				},
+			},
+		},
+		.drdy_irq = {
+			.addr = ST_ACCEL_5_DRDY_IRQ_ADDR,
+			.mask_int1 = ST_ACCEL_5_DRDY_IRQ_INT1_MASK,
+			.mask_int2 = ST_ACCEL_5_DRDY_IRQ_INT2_MASK,
+		},
+		.multi_read_bit = ST_ACCEL_5_MULTIREAD_BIT,
+		.bootime = 2, /* guess */
+	},
 };
 
 static int st_accel_read_raw(struct iio_dev *indio_dev,

drivers/iio/accel/st_accel_i2c.c

@@ -48,6 +48,10 @@ static const struct of_device_id st_accel_of_match[] = {
 		.compatible = "st,lsm330dlc-accel",
 		.data = LSM330DLC_ACCEL_DEV_NAME,
 	},
+	{
+		.compatible = "st,lis331dl-accel",
+		.data = LIS331DL_ACCEL_DEV_NAME,
+	},
 	{
 		.compatible = "st,lis331dlh-accel",
 		.data = LIS331DLH_ACCEL_DEV_NAME,