On Tue, May 19, 2020 at 02:43:54PM +0200, Jonathan Albrieux wrote: > According to AK09911 datasheet, if reset gpio is provided then > deassert reset on ak8975_power_on() and assert reset on ak8975_power_off(). > > Without reset's deassertion during ak8975_power_on(), driver's probe fails > on ak8975_who_i_am while() checking for device identity for AK09911 chip.
Wrong position of (), but hold on, this is so minor, no need to send a new version because of this. > AK09911 has an active low reset gpio to handle register's reset. > AK09911 datasheed says that, if not used, reset pin should be connected > to VID. This patch emulates this situation. Reviewed-by: Andy Shevchenko <[email protected]> > Signed-off-by: Jonathan Albrieux <[email protected]> > --- > drivers/iio/magnetometer/ak8975.c | 18 ++++++++++++++++++ > 1 file changed, 18 insertions(+) > > diff --git a/drivers/iio/magnetometer/ak8975.c > b/drivers/iio/magnetometer/ak8975.c > index fd368455cd7b..a23422aad97d 100644 > --- a/drivers/iio/magnetometer/ak8975.c > +++ b/drivers/iio/magnetometer/ak8975.c > @@ -358,6 +358,7 @@ struct ak8975_data { > u8 asa[3]; > long raw_to_gauss[3]; > struct gpio_desc *eoc_gpiod; > + struct gpio_desc *reset_gpiod; > int eoc_irq; > wait_queue_head_t data_ready_queue; > unsigned long flags; > @@ -384,6 +385,9 @@ static int ak8975_power_on(const struct ak8975_data *data) > "Failed to enable specified Vid supply\n"); > return ret; > } > + > + gpiod_set_value_cansleep(data->reset_gpiod, 0); > + > /* > * According to the datasheet the power supply rise time is 200us > * and the minimum wait time before mode setting is 100us, in > @@ -396,6 +400,8 @@ static int ak8975_power_on(const struct ak8975_data *data) > /* Disable attached power regulator if any. */ > static void ak8975_power_off(const struct ak8975_data *data) > { > + gpiod_set_value_cansleep(data->reset_gpiod, 1); > + > regulator_disable(data->vid); > regulator_disable(data->vdd); > } > @@ -839,6 +845,7 @@ static int ak8975_probe(struct i2c_client *client, > struct ak8975_data *data; > struct iio_dev *indio_dev; > struct gpio_desc *eoc_gpiod; > + struct gpio_desc *reset_gpiod; > const void *match; > unsigned int i; > int err; > @@ -856,6 +863,16 @@ static int ak8975_probe(struct i2c_client *client, > if (eoc_gpiod) > gpiod_set_consumer_name(eoc_gpiod, "ak_8975"); > > + /* > + * According to AK09911 datasheet, if reset GPIO is provided then > + * deassert reset on ak8975_power_on() and assert reset on > + * ak8975_power_off(). > + */ > + reset_gpiod = devm_gpiod_get_optional(&client->dev, > + "reset", GPIOD_OUT_HIGH); > + if (IS_ERR(reset_gpiod)) > + return PTR_ERR(reset_gpiod); > + > /* Register with IIO */ > indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); > if (indio_dev == NULL) > @@ -866,6 +883,7 @@ static int ak8975_probe(struct i2c_client *client, > > data->client = client; > data->eoc_gpiod = eoc_gpiod; > + data->reset_gpiod = reset_gpiod; > data->eoc_irq = 0; > > err = iio_read_mount_matrix(&client->dev, "mount-matrix", > &data->orientation); > -- > 2.17.1 > -- With Best Regards, Andy Shevchenko
