According to the datasheet of BMP38x and BMP390 devices, in SPI
operation, the first byte that returns after a read operation is
garbage and it needs to be dropped and return the rest of the
bytes.
Signed-off-by: Vasileios Amoiridis <vassilisamir@xxxxxxxxx>
---
drivers/iio/pressure/bmp280-spi.c | 47 ++++++++++++++++++++++++++++++-
drivers/iio/pressure/bmp280.h | 2 ++
2 files changed, 48 insertions(+), 1 deletion(-)
diff --git a/drivers/iio/pressure/bmp280-spi.c b/drivers/iio/pressure/bmp280-spi.c
index 433d6fac83c4..c4b4a5d67f94 100644
--- a/drivers/iio/pressure/bmp280-spi.c
+++ b/drivers/iio/pressure/bmp280-spi.c
@@ -35,6 +35,32 @@ static int bmp280_regmap_spi_read(void *context, const void *reg,
return spi_write_then_read(spi, reg, reg_size, val, val_size);
}
+static int bmp380_regmap_spi_read(void *context, const void *reg,
+ size_t reg_size, void *val, size_t val_size)
+{
+ struct spi_device *spi = to_spi_device(context);
+ u8 ret[BMP380_SPI_MAX_REG_COUNT_READ + 1];
+ ssize_t status;
+ u8 buf;
+
+ memcpy(&buf, reg, reg_size);
+ buf |= 0x80;
+
+ /*
+ * According to the BMP380, BMP388, BMP390 datasheets, for a basic
+ * read operation, after the write is done, 2 bytes are received and
+ * the first one has to be dropped. The 2nd one is the requested
+ * value.
+ */
+ status = spi_write_then_read(spi, &buf, 1, ret, val_size + 1);
+ if (status)
+ return status;
+
+ memcpy(val, ret + 1, val_size);
+
+ return 0;
+}
+
static struct regmap_bus bmp280_regmap_bus = {
.write = bmp280_regmap_spi_write,
.read = bmp280_regmap_spi_read,
@@ -42,10 +68,18 @@ static struct regmap_bus bmp280_regmap_bus = {
.val_format_endian_default = REGMAP_ENDIAN_BIG,
};
+static struct regmap_bus bmp380_regmap_bus = {
+ .write = bmp280_regmap_spi_write,
+ .read = bmp380_regmap_spi_read,
+ .reg_format_endian_default = REGMAP_ENDIAN_BIG,
+ .val_format_endian_default = REGMAP_ENDIAN_BIG,
+};
+
static int bmp280_spi_probe(struct spi_device *spi)
{
const struct spi_device_id *id = spi_get_device_id(spi);
const struct bmp280_chip_info *chip_info;
+ struct regmap_bus *bmp_regmap_bus;
struct regmap *regmap;
int ret;
@@ -58,8 +92,19 @@ static int bmp280_spi_probe(struct spi_device *spi)
chip_info = spi_get_device_match_data(spi);
+ switch (chip_info->chip_id[0]) {
+ case BMP380_CHIP_ID:
+ case BMP390_CHIP_ID:
+ bmp_regmap_bus = &bmp380_regmap_bus;
+ break;
+ default:
+ bmp_regmap_bus = &bmp280_regmap_bus;
+ break;
+ }
+
+
regmap = devm_regmap_init(&spi->dev,
- &bmp280_regmap_bus,
+ bmp_regmap_bus,
&spi->dev,
chip_info->regmap_config);
if (IS_ERR(regmap)) {
diff --git a/drivers/iio/pressure/bmp280.h b/drivers/iio/pressure/bmp280.h
index 4012387d7956..ca482b7e4295 100644
--- a/drivers/iio/pressure/bmp280.h
+++ b/drivers/iio/pressure/bmp280.h
@@ -191,6 +191,8 @@
#define BMP380_TEMP_SKIPPED 0x800000
#define BMP380_PRESS_SKIPPED 0x800000
+#define BMP380_SPI_MAX_REG_COUNT_READ 3
+
/* BMP280 specific registers */
#define BMP280_REG_HUMIDITY_LSB 0xFE
#define BMP280_REG_HUMIDITY_MSB 0xFD
--
2.25.1
