commit
4bdc9029685ac03be50b320b29691766d2326c2b upstream.
The gyroscope chip might need to be reset to be used.
Without the chip being reset, the driver stopped at the first
regmap_read (to get the CHIP_ID) and failed to probe.
The datasheet of the gyroscope says that a minimum wait of 30ms after
the reset has to be done.
This patch has been checked on a BMX055 and the datasheet of the BMG160
and the BMI055 give the same reset register and bits.
Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/regmap.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/regmap.h>
+#include <linux/delay.h>
#include "bmg160.h"
#define BMG160_IRQ_NAME "bmg160_event"
#include "bmg160.h"
#define BMG160_IRQ_NAME "bmg160_event"
#define BMG160_NO_FILTER 0
#define BMG160_DEF_BW 100
#define BMG160_NO_FILTER 0
#define BMG160_DEF_BW 100
+#define BMG160_GYRO_REG_RESET 0x14
+#define BMG160_GYRO_RESET_VAL 0xb6
+
#define BMG160_REG_INT_MAP_0 0x17
#define BMG160_INT_MAP_0_BIT_ANY BIT(1)
#define BMG160_REG_INT_MAP_0 0x17
#define BMG160_INT_MAP_0_BIT_ANY BIT(1)
int ret;
unsigned int val;
int ret;
unsigned int val;
+ /*
+ * Reset chip to get it in a known good state. A delay of 30ms after
+ * reset is required according to the datasheet.
+ */
+ regmap_write(data->regmap, BMG160_GYRO_REG_RESET,
+ BMG160_GYRO_RESET_VAL);
+ usleep_range(30000, 30700);
+
ret = regmap_read(data->regmap, BMG160_REG_CHIP_ID, &val);
if (ret < 0) {
dev_err(data->dev, "Error reading reg_chip_id\n");
ret = regmap_read(data->regmap, BMG160_REG_CHIP_ID, &val);
if (ret < 0) {
dev_err(data->dev, "Error reading reg_chip_id\n");