On Tue, May 19, 2020 at 03:25:12PM +0200, Stephan Gerhold wrote: > 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. > > > > AK09911 has an active low reset gpio to handle register's reset. > > AK09911 datasheed says that, if not used, reset pin should be connected > > Another minor typo: datasheed -> datasheet > > In any case, FWIW: > Reviewed-by: Stephan Gerhold <[email protected]> > > > to VID. This patch emulates this situation. > > > > 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
Thank you, will fix that typo too, Best regards, Jonathan Albrieux
