According to the BMA253 datasheet [1] and BMA250 datasheet [2] the bandwidth value for BMA25x should be set as 01xxx: "Settings 00xxx result in a bandwidth of 7.81 Hz; [...] It is recommended [...] to use the range from ´01000b´ to ´01111b´ only in order to be compatible with future products." However, at the moment the drivers sets bandwidth values from 0 to 6, which is not recommended and always results into 7.81 Hz bandwidth according to the datasheet. Fix this by introducing a bw_offset = 8 = 01000b for BMA25x, so the additional bit is always set for BMA25x. [1]: https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bma253-ds000.pdf [2]: https://datasheet.octopart.com/BMA250-Bosch-datasheet-15540103.pdf Cc: Peter Meerwald <pmeerw@xxxxxxxxxx> Cc: Linus Walleij <linus.walleij@xxxxxxxxxx> Fixes: 2017cff24cc0 ("iio:bma180: Add BMA250 chip support") Signed-off-by: Stephan Gerhold <stephan@xxxxxxxxxxx> --- After spending some more time with the driver I noticed that BMA253/BMA254 would actually be better supported by the bmc150-accel driver (which doesn't have this problem and also supports the motion trigger/interrupt). I'm preparing a separate patch set to move BMA254 to bmc150-accel at least, but I'm not sure about BMA250 so this patch is relevant anyway. And I had it almost done already, so I thought it's better to send it. :) --- drivers/iio/accel/bma180.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/iio/accel/bma180.c b/drivers/iio/accel/bma180.c index 97e991581960..81d1e070a2ee 100644 --- a/drivers/iio/accel/bma180.c +++ b/drivers/iio/accel/bma180.c @@ -55,7 +55,7 @@ struct bma180_part_info { u8 int_reset_reg, int_reset_mask; u8 sleep_reg, sleep_mask; - u8 bw_reg, bw_mask; + u8 bw_reg, bw_mask, bw_offset; u8 scale_reg, scale_mask; u8 power_reg, power_mask, lowpower_val; u8 int_enable_reg, int_enable_mask; @@ -127,6 +127,7 @@ struct bma180_part_info { #define BMA250_RANGE_MASK GENMASK(3, 0) /* Range of accel values */ #define BMA250_BW_MASK GENMASK(4, 0) /* Accel bandwidth */ +#define BMA250_BW_OFFSET 8 #define BMA250_SUSPEND_MASK BIT(7) /* chip will sleep */ #define BMA250_LOWPOWER_MASK BIT(6) #define BMA250_DATA_INTEN_MASK BIT(4) @@ -143,6 +144,7 @@ struct bma180_part_info { #define BMA254_RANGE_MASK GENMASK(3, 0) /* Range of accel values */ #define BMA254_BW_MASK GENMASK(4, 0) /* Accel bandwidth */ +#define BMA254_BW_OFFSET 8 #define BMA254_SUSPEND_MASK BIT(7) /* chip will sleep */ #define BMA254_LOWPOWER_MASK BIT(6) #define BMA254_DATA_INTEN_MASK BIT(4) @@ -287,7 +289,8 @@ static int bma180_set_bw(struct bma180_data *data, int val) for (i = 0; i < data->part_info->num_bw; ++i) { if (data->part_info->bw_table[i] == val) { ret = bma180_set_bits(data, data->part_info->bw_reg, - data->part_info->bw_mask, i); + data->part_info->bw_mask, + i + data->part_info->bw_offset); if (ret) { dev_err(&data->client->dev, "failed to set bandwidth\n"); @@ -880,6 +883,7 @@ static const struct bma180_part_info bma180_part_info[] = { .sleep_mask = BMA250_SUSPEND_MASK, .bw_reg = BMA250_BW_REG, .bw_mask = BMA250_BW_MASK, + .bw_offset = BMA250_BW_OFFSET, .scale_reg = BMA250_RANGE_REG, .scale_mask = BMA250_RANGE_MASK, .power_reg = BMA250_POWER_REG, @@ -909,6 +913,7 @@ static const struct bma180_part_info bma180_part_info[] = { .sleep_mask = BMA254_SUSPEND_MASK, .bw_reg = BMA254_BW_REG, .bw_mask = BMA254_BW_MASK, + .bw_offset = BMA254_BW_OFFSET, .scale_reg = BMA254_RANGE_REG, .scale_mask = BMA254_RANGE_MASK, .power_reg = BMA254_POWER_REG, -- 2.31.1
