This is a note to let you know that I've just added the patch titled
iio: pressure: Fixes BMP38x and BMP390 SPI support
to my char-misc git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From a9dd9ba323114f366eb07f1d9630822f8df6cbb2 Mon Sep 17 00:00:00 2001
From: Vasileios Amoiridis <vassilisamir@xxxxxxxxx>
Date: Mon, 19 Feb 2024 20:13:59 +0100
Subject: iio: pressure: Fixes BMP38x and BMP390 SPI support
According to the datasheet of BMP38x and BMP390 devices, for an SPI
read operation the first byte that is returned needs to be dropped,
and the rest of the bytes are the actual data returned from the
sensor.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Fixes: 8d329309184d ("iio: pressure: bmp280: Add support for BMP380 sensor family")
Signed-off-by: Vasileios Amoiridis <vassilisamir@xxxxxxxxx>
Acked-by: Angel Iglesias <ang.iglesiasg@xxxxxxxxx>
Link: https://lore.kernel.org/r/20240219191359.18367-1-vassilisamir@xxxxxxxxx
Cc: <Stable@xxxxxxxxxxxxxxx>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
---
drivers/iio/pressure/bmp280-spi.c | 50 ++++++++++++++++++++++++++++++-
1 file changed, 49 insertions(+), 1 deletion(-)
diff --git a/drivers/iio/pressure/bmp280-spi.c b/drivers/iio/pressure/bmp280-spi.c
index e8a5fed07e88..a444d4b2978b 100644
--- a/drivers/iio/pressure/bmp280-spi.c
+++ b/drivers/iio/pressure/bmp280-spi.c
@@ -4,6 +4,7 @@
*
* Inspired by the older BMP085 driver drivers/misc/bmp085-spi.c
*/
+#include <linux/bits.h>
#include <linux/module.h>
#include <linux/spi/spi.h>
#include <linux/err.h>
@@ -35,6 +36,34 @@ 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 rx_buf[4];
+ ssize_t status;
+
+ /*
+ * Maximum number of consecutive bytes read for a temperature or
+ * pressure measurement is 3.
+ */
+ if (val_size > 3)
+ return -EINVAL;
+
+ /*
+ * According to the BMP3xx datasheets, for a basic SPI read opertion,
+ * the first byte needs to be dropped and the rest are the requested
+ * data.
+ */
+ status = spi_write_then_read(spi, reg, 1, rx_buf, val_size + 1);
+ if (status)
+ return status;
+
+ memcpy(val, rx_buf + 1, val_size);
+
+ return 0;
+}
+
static struct regmap_bus bmp280_regmap_bus = {
.write = bmp280_regmap_spi_write,
.read = bmp280_regmap_spi_read,
@@ -42,10 +71,19 @@ 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,
+ .read_flag_mask = BIT(7),
+ .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 +96,18 @@ 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)) {
--
2.44.0
