[PATCH v6 0/4] iio: magnetometer: ak8975: Add gpio reset support

[PATCH v6 0/4] iio: magnetometer: ak8975: Add gpio reset support

[Jonathan Albrieux]

v6:
 - reword documentation for gpios, add interrupt documentation

v5:
 - add maintainer
https://lore.kernel.org/linux-iio/20200520163417.27805-1-jonathan.albrieux@gmail.com/

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/20200520073125.30808-1-jonathan.albrieux@gmail.com/

v3:
 - fix patch messages style
 - align reset gpio comment to kernel doc reccomendation
 - introduce changelog
https://lore.kernel.org/linux-iio/20200519124402.26076-1-jonathan.albrieux@gmail.com/

v2:
 - rewording of reset gpio comment and patch messages to better clarify
   reset gpio behaviour
https://lore.kernel.org/linux-iio/20200518133645.19127-1-jonathan.albrieux@gmail.com/

v1:
 - initial patch submission
https://lore.kernel.org/linux-iio/20200519065749.4624-1-jonathan.albrieux@gmail.com/

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 (5):
  dt-bindings: iio: magnetometer: ak8975: reword gpios, add interrupts,
    fix style
  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 -------
 .../iio/magnetometer/asahi-kasei,ak8975.yaml  | 85 +++++++++++++++++++
 drivers/iio/magnetometer/ak8975.c             | 22 ++++-
 3 files changed, 105 insertions(+), 32 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/iio/magnetometer/ak8975.txt
 create mode 100644 Documentation/devicetree/bindings/iio/magnetometer/asahi-kasei,ak8975.yaml

-- 
2.17.1

[PATCH v6 1/5] dt-bindings: iio: magnetometer: ak8975: reword gpios, add interrupts, fix style

[Jonathan Albrieux]

Reword gpios documentation, add interrupt documentation and fix styles.
Update example to use interrupts instead of gpios.

Signed-off-by: Jonathan Albrieux <jonathan.albrieux@gmail.com>
---
 .../bindings/iio/magnetometer/ak8975.txt      | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/Documentation/devicetree/bindings/iio/magnetometer/ak8975.txt b/Documentation/devicetree/bindings/iio/magnetometer/ak8975.txt
index aa67ceb0d4e0..0576b9df0bf2 100644
--- a/Documentation/devicetree/bindings/iio/magnetometer/ak8975.txt
+++ b/Documentation/devicetree/bindings/iio/magnetometer/ak8975.txt
@@ -2,21 +2,28 @@
 
 Required properties:
 
-  - compatible : should be "asahi-kasei,ak8975"
-  - reg : the I2C address of the magnetometer
+  - compatible : should be "asahi-kasei,ak8975".
+  - reg : the I2C address of the magnetometer.
 
 Optional properties:
 
-  - gpios : should be device tree identifier of the magnetometer DRDY pin
-  - vdd-supply: an optional regulator that needs to be on to provide VDD
-  - mount-matrix: an optional 3x3 mounting rotation matrix
+  - gpios : AK8975 has a "Data ready" pin (DRDY) which informs that data
+      is ready to be read and is possible to listen on it. If used,
+      this should be active high. Prefer interrupt over this.
+
+  - interrupts : interrupt for DRDY pin. Triggered on rising edge.
+
+  - vdd-supply: an optional regulator that needs to be on to provide VDD.
+
+  - mount-matrix: an optional 3x3 mounting rotation matrix.
 
 Example:
 
 ak8975@c {
         compatible = "asahi-kasei,ak8975";
         reg = <0x0c>;
-        gpios = <&gpj0 7 0>;
+        interrupt-parent = <&gpio6>;
+        interrupts = <15 IRQ_TYPE_EDGE_RISING>;
         vdd-supply = <&ldo_3v3_gnss>;
         mount-matrix = "-0.984807753012208",  /* x0 */
                        "0",                   /* y0 */
-- 
2.17.1

[PATCH v6 2/5] dt-bindings: iio: magnetometer: ak8975: convert format to yaml, add maintainer

[Jonathan Albrieux]

Converts documentation from txt format to yaml.

Signed-off-by: Jonathan Albrieux <jonathan.albrieux@gmail.com>
---
 .../bindings/iio/magnetometer/ak8975.txt      | 37 ---------
 .../iio/magnetometer/asahi-kasei,ak8975.yaml  | 78 +++++++++++++++++++
 2 files changed, 78 insertions(+), 37 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/iio/magnetometer/ak8975.txt
 create mode 100644 Documentation/devicetree/bindings/iio/magnetometer/asahi-kasei,ak8975.yaml

diff --git a/Documentation/devicetree/bindings/iio/magnetometer/ak8975.txt b/Documentation/devicetree/bindings/iio/magnetometer/ak8975.txt
deleted file mode 100644
index 0576b9df0bf2..000000000000
--- a/Documentation/devicetree/bindings/iio/magnetometer/ak8975.txt
+++ /dev/null
@@ -1,37 +0,0 @@
-* AsahiKASEI AK8975 magnetometer sensor
-
-Required properties:
-
-  - compatible : should be "asahi-kasei,ak8975".
-  - reg : the I2C address of the magnetometer.
-
-Optional properties:
-
-  - gpios : AK8975 has a "Data ready" pin (DRDY) which informs that data
-      is ready to be read and is possible to listen on it. If used,
-      this should be active high. Prefer interrupt over this.
-
-  - interrupts : interrupt for DRDY pin. Triggered on rising edge.
-
-  - vdd-supply: an optional regulator that needs to be on to provide VDD.
-
-  - mount-matrix: an optional 3x3 mounting rotation matrix.
-
-Example:
-
-ak8975@c {
-        compatible = "asahi-kasei,ak8975";
-        reg = <0x0c>;
-        interrupt-parent = <&gpio6>;
-        interrupts = <15 IRQ_TYPE_EDGE_RISING>;
-        vdd-supply = <&ldo_3v3_gnss>;
-        mount-matrix = "-0.984807753012208",  /* x0 */
-                       "0",                   /* y0 */
-                       "-0.173648177666930",  /* z0 */
-                       "0",                   /* x1 */
-                       "-1",                  /* y1 */
-                       "0",                   /* z1 */
-                       "-0.173648177666930",  /* x2 */
-                       "0",                   /* y2 */
-                       "0.984807753012208";   /* z2 */
-};
diff --git a/Documentation/devicetree/bindings/iio/magnetometer/asahi-kasei,ak8975.yaml b/Documentation/devicetree/bindings/iio/magnetometer/asahi-kasei,ak8975.yaml
new file mode 100644
index 000000000000..a603659d5fa5
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/magnetometer/asahi-kasei,ak8975.yaml
@@ -0,0 +1,78 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/magnetometer/asahi-kasei,ak8975.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: AsahiKASEI AK8975 magnetometer sensor
+
+maintainers:
+  - Jonathan Albrieux <jonathan.albrieux@gmail.com>
+
+properties:
+  compatible:
+    oneOf:
+      - const: asahi-kasei,ak8975
+      - const: asahi-kasei,ak8963
+      - const: asahi-kasei,ak09911
+      - const: asahi-kasei,ak09912
+      - const: ak8975
+        deprecated: true
+      - const: ak8963
+        deprecated: true
+      - const: ak09911
+        deprecated: true
+      - const: ak09912
+        deprecated: true
+
+  reg:
+    maxItems: 1
+    description: the I2C address of the magnetometer.
+
+  gpios:
+    description: |
+      AK8975 has a "Data ready" pin (DRDY) which informs that data
+      is ready to be read and is possible to listen on it. If used,
+      this should be active high. Prefer interrupt over this.
+
+  interrupts:
+    maxItems: 1
+    description: interrupt for DRDY pin. Triggered on rising edge.
+
+  vdd-supply:
+    maxItems: 1
+    description: |
+      an optional regulator that needs to be on to provide VDD power to
+      the sensor.
+
+  mount-matrix:
+    description: an optional 3x3 mounting rotation matrix.
+
+required:
+  - compatible
+  - reg
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        magnetometer@c {
+            compatible = "asahi-kasei,ak8975";
+            reg = <0x0c>;
+            interrupt-parent = <&gpio6>;
+            interrupts = <15 IRQ_TYPE_EDGE_RISING>;
+            vdd-supply = <&ldo_3v3_gnss>;
+            mount-matrix = "-0.984807753012208",  /* x0 */
+                           "0",                   /* y0 */
+                           "-0.173648177666930",  /* z0 */
+                           "0",                   /* x1 */
+                           "-1",                  /* y1 */
+                           "0",                   /* z1 */
+                           "-0.173648177666930",  /* x2 */
+                           "0",                   /* y2 */
+                           "0.984807753012208";   /* z2 */
+        };
+    };
-- 
2.17.1

[PATCH v6 3/5] dt-bindings: iio: magnetometer: ak8975: add gpio reset support

[Jonathan Albrieux]

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 <jonathan.albrieux@gmail.com>
---
 .../bindings/iio/magnetometer/asahi-kasei,ak8975.yaml      | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/magnetometer/asahi-kasei,ak8975.yaml b/Documentation/devicetree/bindings/iio/magnetometer/asahi-kasei,ak8975.yaml
index a603659d5fa5..04b895c7143c 100644
--- a/Documentation/devicetree/bindings/iio/magnetometer/asahi-kasei,ak8975.yaml
+++ b/Documentation/devicetree/bindings/iio/magnetometer/asahi-kasei,ak8975.yaml
@@ -48,6 +48,11 @@ properties:
   mount-matrix:
     description: an optional 3x3 mounting rotation matrix.
 
+  reset-gpios:
+    description: |
+      an optional pin needed for AK09911 to set the reset state. This should
+      be usually active low
+
 required:
   - compatible
   - reg
@@ -55,6 +60,7 @@ required:
 examples:
   - |
     #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/gpio/gpio.h>
     i2c {
         #address-cells = <1>;
         #size-cells = <0>;
@@ -65,6 +71,7 @@ examples:
             interrupt-parent = <&gpio6>;
             interrupts = <15 IRQ_TYPE_EDGE_RISING>;
             vdd-supply = <&ldo_3v3_gnss>;
+            reset-gpios = <&msmgpio 111 GPIO_ACTIVE_LOW>;
             mount-matrix = "-0.984807753012208",  /* x0 */
                            "0",                   /* y0 */
                            "-0.173648177666930",  /* z0 */
-- 
2.17.1

[PATCH v6 4/5] iio: magnetometer: ak8975: Fix typo, uniform measurement unit style

[Jonathan Albrieux]

Minor comment style edits.

Signed-off-by: Jonathan Albrieux <jonathan.albrieux@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 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

[PATCH v6 5/5] iio: magnetometer: ak8975: Add gpio reset support

[Jonathan Albrieux]

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>
---
 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

Re: [PATCH v6 3/5] dt-bindings: iio: magnetometer: ak8975: add gpio reset support

[Linus Walleij]

On Mon, May 25, 2020 at 5:13 PM Jonathan Albrieux
<jonathan.albrieux@gmail.com> wrote:

> 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 <jonathan.albrieux@gmail.com>

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij

Re: [PATCH v6 3/5] dt-bindings: iio: magnetometer: ak8975: add gpio reset support

[Jonathan Albrieux]

On Tue, May 26, 2020 at 11:22:07AM +0200, Linus Walleij wrote:
> On Mon, May 25, 2020 at 5:13 PM Jonathan Albrieux
> <jonathan.albrieux@gmail.com> wrote:
> 
> > 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 <jonathan.albrieux@gmail.com>
> 
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> 
> Yours,
> Linus Walleij

Thank you!!

Best regards,
Jonathan Albrieux

Re: [PATCH v6 1/5] dt-bindings: iio: magnetometer: ak8975: reword gpios, add interrupts, fix style

[Rob Herring]

On Mon, 25 May 2020 17:10:35 +0200, Jonathan Albrieux wrote:
> Reword gpios documentation, add interrupt documentation and fix styles.
> Update example to use interrupts instead of gpios.
> 
> Signed-off-by: Jonathan Albrieux <jonathan.albrieux@gmail.com>
> ---
>  .../bindings/iio/magnetometer/ak8975.txt      | 19 +++++++++++++------
>  1 file changed, 13 insertions(+), 6 deletions(-)
> 

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH v6 2/5] dt-bindings: iio: magnetometer: ak8975: convert format to yaml, add maintainer

[Rob Herring]

On Mon, May 25, 2020 at 05:10:36PM +0200, Jonathan Albrieux wrote:
> Converts documentation from txt format to yaml.

I would have converted to yaml and do any re-formatting/wording, then 
added 'interrupts', but this is fine.


> Signed-off-by: Jonathan Albrieux <jonathan.albrieux@gmail.com>
> ---
>  .../bindings/iio/magnetometer/ak8975.txt      | 37 ---------
>  .../iio/magnetometer/asahi-kasei,ak8975.yaml  | 78 +++++++++++++++++++
>  2 files changed, 78 insertions(+), 37 deletions(-)
>  delete mode 100644 Documentation/devicetree/bindings/iio/magnetometer/ak8975.txt
>  create mode 100644 Documentation/devicetree/bindings/iio/magnetometer/asahi-kasei,ak8975.yaml
> 
> diff --git a/Documentation/devicetree/bindings/iio/magnetometer/ak8975.txt b/Documentation/devicetree/bindings/iio/magnetometer/ak8975.txt
> deleted file mode 100644
> index 0576b9df0bf2..000000000000
> --- a/Documentation/devicetree/bindings/iio/magnetometer/ak8975.txt
> +++ /dev/null
> @@ -1,37 +0,0 @@
> -* AsahiKASEI AK8975 magnetometer sensor
> -
> -Required properties:
> -
> -  - compatible : should be "asahi-kasei,ak8975".
> -  - reg : the I2C address of the magnetometer.
> -
> -Optional properties:
> -
> -  - gpios : AK8975 has a "Data ready" pin (DRDY) which informs that data
> -      is ready to be read and is possible to listen on it. If used,
> -      this should be active high. Prefer interrupt over this.
> -
> -  - interrupts : interrupt for DRDY pin. Triggered on rising edge.
> -
> -  - vdd-supply: an optional regulator that needs to be on to provide VDD.
> -
> -  - mount-matrix: an optional 3x3 mounting rotation matrix.
> -
> -Example:
> -
> -ak8975@c {
> -        compatible = "asahi-kasei,ak8975";
> -        reg = <0x0c>;
> -        interrupt-parent = <&gpio6>;
> -        interrupts = <15 IRQ_TYPE_EDGE_RISING>;
> -        vdd-supply = <&ldo_3v3_gnss>;
> -        mount-matrix = "-0.984807753012208",  /* x0 */
> -                       "0",                   /* y0 */
> -                       "-0.173648177666930",  /* z0 */
> -                       "0",                   /* x1 */
> -                       "-1",                  /* y1 */
> -                       "0",                   /* z1 */
> -                       "-0.173648177666930",  /* x2 */
> -                       "0",                   /* y2 */
> -                       "0.984807753012208";   /* z2 */
> -};
> diff --git a/Documentation/devicetree/bindings/iio/magnetometer/asahi-kasei,ak8975.yaml b/Documentation/devicetree/bindings/iio/magnetometer/asahi-kasei,ak8975.yaml
> new file mode 100644
> index 000000000000..a603659d5fa5
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/magnetometer/asahi-kasei,ak8975.yaml
> @@ -0,0 +1,78 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/magnetometer/asahi-kasei,ak8975.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: AsahiKASEI AK8975 magnetometer sensor
> +
> +maintainers:
> +  - Jonathan Albrieux <jonathan.albrieux@gmail.com>
> +
> +properties:
> +  compatible:
> +    oneOf:
> +      - const: asahi-kasei,ak8975
> +      - const: asahi-kasei,ak8963
> +      - const: asahi-kasei,ak09911
> +      - const: asahi-kasei,ak09912

These 4 can be an enum.

> +      - const: ak8975
> +        deprecated: true
> +      - const: ak8963
> +        deprecated: true
> +      - const: ak09911
> +        deprecated: true
> +      - const: ak09912
> +        deprecated: true

And these 4 can be an enum+deprecated.

> +
> +  reg:
> +    maxItems: 1
> +    description: the I2C address of the magnetometer.

Don't need a description.

> +
> +  gpios:
> +    description: |
> +      AK8975 has a "Data ready" pin (DRDY) which informs that data
> +      is ready to be read and is possible to listen on it. If used,
> +      this should be active high. Prefer interrupt over this.

Need to define how many GPIOs (maxItems: 1).

> +
> +  interrupts:
> +    maxItems: 1
> +    description: interrupt for DRDY pin. Triggered on rising edge.
> +
> +  vdd-supply:
> +    maxItems: 1
> +    description: |
> +      an optional regulator that needs to be on to provide VDD power to
> +      the sensor.
> +
> +  mount-matrix:
> +    description: an optional 3x3 mounting rotation matrix.
> +
> +required:
> +  - compatible
> +  - reg
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    i2c {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        magnetometer@c {
> +            compatible = "asahi-kasei,ak8975";
> +            reg = <0x0c>;
> +            interrupt-parent = <&gpio6>;
> +            interrupts = <15 IRQ_TYPE_EDGE_RISING>;
> +            vdd-supply = <&ldo_3v3_gnss>;
> +            mount-matrix = "-0.984807753012208",  /* x0 */
> +                           "0",                   /* y0 */
> +                           "-0.173648177666930",  /* z0 */
> +                           "0",                   /* x1 */
> +                           "-1",                  /* y1 */
> +                           "0",                   /* z1 */
> +                           "-0.173648177666930",  /* x2 */
> +                           "0",                   /* y2 */
> +                           "0.984807753012208";   /* z2 */
> +        };
> +    };
> -- 
> 2.17.1
> 

Re: [PATCH v6 3/5] dt-bindings: iio: magnetometer: ak8975: add gpio reset support

[Rob Herring]

On Mon, 25 May 2020 17:10:37 +0200, Jonathan Albrieux wrote:
> 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 <jonathan.albrieux@gmail.com>
> ---
>  .../bindings/iio/magnetometer/asahi-kasei,ak8975.yaml      | 7 +++++++
>  1 file changed, 7 insertions(+)
> 

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH v6 2/5] dt-bindings: iio: magnetometer: ak8975: convert format to yaml, add maintainer

[Jonathan Albrieux]

On Tue, May 26, 2020 at 04:28:47PM -0600, Rob Herring wrote:
> On Mon, May 25, 2020 at 05:10:36PM +0200, Jonathan Albrieux wrote:
> > Converts documentation from txt format to yaml.
> 
> I would have converted to yaml and do any re-formatting/wording, then 
> added 'interrupts', but this is fine.
>

Thank you, I'll keep that in mind for future works like this one
 
> 
> > Signed-off-by: Jonathan Albrieux <jonathan.albrieux@gmail.com>
> > ---
> >  .../bindings/iio/magnetometer/ak8975.txt      | 37 ---------
> >  .../iio/magnetometer/asahi-kasei,ak8975.yaml  | 78 +++++++++++++++++++
> >  2 files changed, 78 insertions(+), 37 deletions(-)
> >  delete mode 100644 Documentation/devicetree/bindings/iio/magnetometer/ak8975.txt
> >  create mode 100644 Documentation/devicetree/bindings/iio/magnetometer/asahi-kasei,ak8975.yaml
> > 
> > diff --git a/Documentation/devicetree/bindings/iio/magnetometer/ak8975.txt b/Documentation/devicetree/bindings/iio/magnetometer/ak8975.txt
> > deleted file mode 100644
> > index 0576b9df0bf2..000000000000
> > --- a/Documentation/devicetree/bindings/iio/magnetometer/ak8975.txt
> > +++ /dev/null
> > @@ -1,37 +0,0 @@
> > -* AsahiKASEI AK8975 magnetometer sensor
> > -
> > -Required properties:
> > -
> > -  - compatible : should be "asahi-kasei,ak8975".
> > -  - reg : the I2C address of the magnetometer.
> > -
> > -Optional properties:
> > -
> > -  - gpios : AK8975 has a "Data ready" pin (DRDY) which informs that data
> > -      is ready to be read and is possible to listen on it. If used,
> > -      this should be active high. Prefer interrupt over this.
> > -
> > -  - interrupts : interrupt for DRDY pin. Triggered on rising edge.
> > -
> > -  - vdd-supply: an optional regulator that needs to be on to provide VDD.
> > -
> > -  - mount-matrix: an optional 3x3 mounting rotation matrix.
> > -
> > -Example:
> > -
> > -ak8975@c {
> > -        compatible = "asahi-kasei,ak8975";
> > -        reg = <0x0c>;
> > -        interrupt-parent = <&gpio6>;
> > -        interrupts = <15 IRQ_TYPE_EDGE_RISING>;
> > -        vdd-supply = <&ldo_3v3_gnss>;
> > -        mount-matrix = "-0.984807753012208",  /* x0 */
> > -                       "0",                   /* y0 */
> > -                       "-0.173648177666930",  /* z0 */
> > -                       "0",                   /* x1 */
> > -                       "-1",                  /* y1 */
> > -                       "0",                   /* z1 */
> > -                       "-0.173648177666930",  /* x2 */
> > -                       "0",                   /* y2 */
> > -                       "0.984807753012208";   /* z2 */
> > -};
> > diff --git a/Documentation/devicetree/bindings/iio/magnetometer/asahi-kasei,ak8975.yaml b/Documentation/devicetree/bindings/iio/magnetometer/asahi-kasei,ak8975.yaml
> > new file mode 100644
> > index 000000000000..a603659d5fa5
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/iio/magnetometer/asahi-kasei,ak8975.yaml
> > @@ -0,0 +1,78 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/iio/magnetometer/asahi-kasei,ak8975.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: AsahiKASEI AK8975 magnetometer sensor
> > +
> > +maintainers:
> > +  - Jonathan Albrieux <jonathan.albrieux@gmail.com>
> > +
> > +properties:
> > +  compatible:
> > +    oneOf:
> > +      - const: asahi-kasei,ak8975
> > +      - const: asahi-kasei,ak8963
> > +      - const: asahi-kasei,ak09911
> > +      - const: asahi-kasei,ak09912
> 
> These 4 can be an enum.
> 
> > +      - const: ak8975
> > +        deprecated: true
> > +      - const: ak8963
> > +        deprecated: true
> > +      - const: ak09911
> > +        deprecated: true
> > +      - const: ak09912
> > +        deprecated: true
> 
> And these 4 can be an enum+deprecated.
> 
> > +
> > +  reg:
> > +    maxItems: 1
> > +    description: the I2C address of the magnetometer.
> 
> Don't need a description.
> 
> > +
> > +  gpios:
> > +    description: |
> > +      AK8975 has a "Data ready" pin (DRDY) which informs that data
> > +      is ready to be read and is possible to listen on it. If used,
> > +      this should be active high. Prefer interrupt over this.
> 
> Need to define how many GPIOs (maxItems: 1).
> 

Ok, I'll edit those fields as soon as possible, thank you,

Best regards,
Jonathan Albrieux

> > +
> > +  interrupts:
> > +    maxItems: 1
> > +    description: interrupt for DRDY pin. Triggered on rising edge.
> > +
> > +  vdd-supply:
> > +    maxItems: 1
> > +    description: |
> > +      an optional regulator that needs to be on to provide VDD power to
> > +      the sensor.
> > +
> > +  mount-matrix:
> > +    description: an optional 3x3 mounting rotation matrix.
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/interrupt-controller/irq.h>
> > +    i2c {
> > +        #address-cells = <1>;
> > +        #size-cells = <0>;
> > +
> > +        magnetometer@c {
> > +            compatible = "asahi-kasei,ak8975";
> > +            reg = <0x0c>;
> > +            interrupt-parent = <&gpio6>;
> > +            interrupts = <15 IRQ_TYPE_EDGE_RISING>;
> > +            vdd-supply = <&ldo_3v3_gnss>;
> > +            mount-matrix = "-0.984807753012208",  /* x0 */
> > +                           "0",                   /* y0 */
> > +                           "-0.173648177666930",  /* z0 */
> > +                           "0",                   /* x1 */
> > +                           "-1",                  /* y1 */
> > +                           "0",                   /* z1 */
> > +                           "-0.173648177666930",  /* x2 */
> > +                           "0",                   /* y2 */
> > +                           "0.984807753012208";   /* z2 */
> > +        };
> > +    };
> > -- 
> > 2.17.1
> >