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Commit 4980301e authored by Stephan Gerhold's avatar Stephan Gerhold Committed by Greg Kroah-Hartman
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iio: accel: bma180: Fix BMA25x bandwidth register values 

commit 8090d67421ddab0ae932abab5a60200598bf0bbb upstream

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@pmeerw.net>
Fixes: 2017cff2 ("iio:bma180: Add BMA250 chip support")
Signed-off-by: default avatarStephan Gerhold <stephan@gerhold.net>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210526094408.34298-2-stephan@gerhold.net


Cc: <Stable@vger.kernel.org>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
[sudip: adjust context]
Signed-off-by: default avatarSudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d04f2582

drivers/iio/accel/bma180.c

+5 −2
Original line number Diff line number Diff line
@@ -47,7 +47,7 @@ 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;
@@ -103,6 +103,7 @@ 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)
@@ -241,7 +242,8 @@ 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");
@@ -669,6 +671,7 @@ 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,