[PATCH] iio: pressure: bmp280: fix bmp580 temp read

[Adam Rizkalla <ajarizzo@gmail.com>]

Fix overflow when storing bmp580 temperature reading and preserve sign.

This patch re-applies the fix in [1] after the merge conflict resolution
mentioned in [2].

[1] https://lore.kernel.org/all/Zin2udkXRD0+GrML@adam-asahi.lan/
[2] https://lore.kernel.org/linux-kernel/20240531140621.264f0848@canb.auug.org.au/

Signed-off-by: Adam Rizkalla <ajarizzo@gmail.com>
---
 drivers/iio/pressure/bmp280-core.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index 95c88b0e1c49..3a003843c79c 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -1752,6 +1752,8 @@ static int bmp580_read_temp(struct bmp280_data *data, s32 *raw_temp)
 		dev_err(data->dev, "reading temperature skipped\n");
 		return -EIO;
 	}
+	*raw_temp = sign_extend32(*raw_temp, 23);
+	*raw_temp = ((s64)*raw_temp * 1000) / (1 << 16);
 
 	return 0;
 }
@@ -2154,7 +2156,7 @@ static irqreturn_t bmp580_buffer_handler(int irq, void *p)
 
 static const int bmp580_oversampling_avail[] = { 1, 2, 4, 8, 16, 32, 64, 128 };
 static const u8 bmp580_chip_ids[] = { BMP580_CHIP_ID, BMP580_CHIP_ID_ALT };
-static const int bmp580_temp_coeffs[] = { 1000, 16 };
+static const int bmp580_temp_coeffs[] = { 1, 0 };
 static const int bmp580_press_coeffs[] = { 1, 64000};
 
 const struct bmp280_chip_info bmp580_chip_info = {
@@ -2184,7 +2186,7 @@ const struct bmp280_chip_info bmp580_chip_info = {
 	.iir_filter_coeff_default = 2,
 
 	.temp_coeffs = bmp580_temp_coeffs,
-	.temp_coeffs_type = IIO_VAL_FRACTIONAL_LOG2,
+	.temp_coeffs_type = IIO_VAL_INT,
 	.press_coeffs = bmp580_press_coeffs,
 	.press_coeffs_type = IIO_VAL_FRACTIONAL,
 
-- 
2.40.1