| Message ID | 20200528150106.12022-1-jonathan.albrieux@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iio: magnetometer: ak8975: Add gpio reset support | expand |
On Thu, 28 May 2020 17:01:05 +0200 Jonathan Albrieux <jonathan.albrieux@gmail.com> 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 datasheet says that, if not used, reset pin should be connected > to VID. This patch emulates this situation. > > Signed-off-by: Jonathan Albrieux <jonathan.albrieux@gmail.com> > Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > Reviewed-by: Stephan Gerhold <stephan@gerhold.net> Applied. Thanks, Jonathan > --- > 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);
On Sun, May 31, 2020 at 12:02:30PM +0100, Jonathan Cameron wrote: > On Thu, 28 May 2020 17:01:05 +0200 > Jonathan Albrieux <jonathan.albrieux@gmail.com> 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 datasheet says that, if not used, reset pin should be connected > > to VID. This patch emulates this situation. > > > > Signed-off-by: Jonathan Albrieux <jonathan.albrieux@gmail.com> > > Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > > Reviewed-by: Stephan Gerhold <stephan@gerhold.net> > > Applied. Thanks, > > Jonathan > Thank you! Best regards, Jonathan Albrieux > > --- > > 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); >
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);