v5:
- add maintainer
v4:
- fix some typo
- use gpio's dt-bindings for more clarity in documentation
- set compatible properties without vendor prefix as deprecated
https://lore.kernel.org/linux-iio/[email protected]/
v3:
- fix patch messages style
- align reset gpio comment to kernel doc reccomendation
- introduce changelog
https://lore.kernel.org/linux-iio/[email protected]/
v2:
- rewording of reset gpio comment and patch messages to better clarify
reset gpio behaviour
https://lore.kernel.org/linux-iio/[email protected]/
v1:
- initial patch submission
https://lore.kernel.org/linux-iio/[email protected]/
Convert documentation from txt format to yaml. Add documentation about
reset-gpio.
Deassert reset on ak8975_power_on(), 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.
Jonathan Albrieux (4):
dt-bindings: iio: magnetometer: ak8975: convert format to yaml, add
maintainer
dt-bindings: iio: magnetometer: ak8975: add gpio reset support
iio: magnetometer: ak8975: Fix typo, uniform measurement unit style
iio: magnetometer: ak8975: Add gpio reset support
.../bindings/iio/magnetometer/ak8975.txt | 30 --------
.../bindings/iio/magnetometer/ak8975.yaml | 77 +++++++++++++++++++
drivers/iio/magnetometer/ak8975.c | 22 +++++-
3 files changed, 97 insertions(+), 32 deletions(-)
delete mode 100644 Documentation/devicetree/bindings/iio/magnetometer/ak8975.txt
create mode 100644 Documentation/devicetree/bindings/iio/magnetometer/ak8975.yaml
--
2.17.1
Add reset-gpio support.
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 <[email protected]>
---
.../devicetree/bindings/iio/magnetometer/ak8975.yaml | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/Documentation/devicetree/bindings/iio/magnetometer/ak8975.yaml b/Documentation/devicetree/bindings/iio/magnetometer/ak8975.yaml
index 8bde423a2ffa..aba9ced7b6da 100644
--- a/Documentation/devicetree/bindings/iio/magnetometer/ak8975.yaml
+++ b/Documentation/devicetree/bindings/iio/magnetometer/ak8975.yaml
@@ -41,6 +41,11 @@ properties:
mount-matrix:
description: an optional 3x3 mounting rotation matrix
+ reset-gpio:
+ description: |
+ an optional pin needed for AK09911 to set the reset state. This should
+ be usually active low
+
required:
- compatible
- reg
@@ -58,6 +63,7 @@ examples:
reg = <0x0c>;
gpios = <&gpj0 7 GPIO_ACTIVE_HIGH>;
vdd-supply = <&ldo_3v3_gnss>;
+ reset-gpio = <&msmgpio 111 GPIO_ACTIVE_LOW>;
mount-matrix = "-0.984807753012208", /* x0 */
"0", /* y0 */
"-0.173648177666930", /* z0 */
--
2.17.1
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 <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Reviewed-by: Stephan Gerhold <[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
Minor comment style edits.
Signed-off-by: Jonathan Albrieux <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
---
drivers/iio/magnetometer/ak8975.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/iio/magnetometer/ak8975.c b/drivers/iio/magnetometer/ak8975.c
index 3c881541ae72..fd368455cd7b 100644
--- a/drivers/iio/magnetometer/ak8975.c
+++ b/drivers/iio/magnetometer/ak8975.c
@@ -385,9 +385,9 @@ static int ak8975_power_on(const struct ak8975_data *data)
return ret;
}
/*
- * According to the datasheet the power supply rise time i 200us
+ * According to the datasheet the power supply rise time is 200us
* and the minimum wait time before mode setting is 100us, in
- * total 300 us. Add some margin and say minimum 500us here.
+ * total 300us. Add some margin and say minimum 500us here.
*/
usleep_range(500, 1000);
return 0;
--
2.17.1
On Wed, 20 May 2020 18:34:09 +0200
Jonathan Albrieux <[email protected]> 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 <[email protected]>
> Reviewed-by: Andy Shevchenko <[email protected]>
> Reviewed-by: Stephan Gerhold <[email protected]>
Looks good to me. Just the minor stuff with the binding plus
giving time for a binding review to go.
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);