SPI bus is never generating error during transfer, so to check if
a chip is correctly connected on a SPI bus we enforce whoami check
to be correct.
In this way we can assure SPI probe is failing if there is no chip
connected.
Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@xxxxxxxxxxxxxx>
---
drivers/iio/imu/inv_mpu6050/inv_mpu_core.c | 21 +++++++++++----------
1 file changed, 11 insertions(+), 10 deletions(-)
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
index 96dabbd..57b3442 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
@@ -774,23 +774,24 @@ static int inv_check_and_setup_chip(struct inv_mpu6050_state *st)
st->hw = &hw_info[st->chip_type];
st->reg = hw_info[st->chip_type].reg;
- /* reset to make sure previous state are not there */
- result = regmap_write(st->map, st->reg->pwr_mgmt_1,
- INV_MPU6050_BIT_H_RESET);
- if (result)
- return result;
- msleep(INV_MPU6050_POWER_UP_TIME);
-
/* check chip self-identification */
result = regmap_read(st->map, INV_MPU6050_REG_WHOAMI, ®val);
if (result)
return result;
if (regval != st->hw->whoami) {
- dev_warn(regmap_get_device(st->map),
- "whoami mismatch got %#02x expected %#02hhx for %s\n",
- regval, st->hw->whoami, st->hw->name);
+ dev_err(regmap_get_device(st->map),
+ "invalid whoami got %#02x expected %#02hhx for %s\n",
+ regval, st->hw->whoami, st->hw->name);
+ return -ENODEV;
}
+ /* reset to make sure previous state are not there */
+ result = regmap_write(st->map, st->reg->pwr_mgmt_1,
+ INV_MPU6050_BIT_H_RESET);
+ if (result)
+ return result;
+ msleep(INV_MPU6050_POWER_UP_TIME);
+
/*
* toggle power state. After reset, the sleep bit could be on
* or off depending on the OTP settings. Toggling power would
--
1.9.1
--
To unsubscribe from this list: send the line "unsubscribe linux-iio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
