[v9,00/11] Add Wacom I2C support to rM2

Add support to the reMarkable2 (rM2) for the Wacom I2C device.

This is based on the reMarkable Linux fork and with this series I am
able to use the Wacom digitiser on the rM2.

v9:
 - Add two new patches
 - Fixup the device tree interrupt line
v7:
 - Fx the compatible name and documentation

Alistair Francis (11):
  dt-bindings: Add Wacom to vendor bindings
  dt-bindings: touchscreen: Initial commit of wacom,i2c
  Input: wacom_i2c - Add device tree support to wacom_i2c
  Input: wacom_i2c - Add touchscren properties
  Input: wacom_i2c - Add support for distance and tilt x/y
  Input: wacom_i2c - Clean up the query device fields
  Input: wacom_i2c - Add support for vdd regulator
  Input: wacom_i2c - Use macros for the bit masks
  Input: wacom_i2c - Allow flipping the values from the DT
  ARM: imx_v6_v7_defconfig: Enable Wacom I2C
  ARM: dts: imx7d: remarkable2: add wacom digitizer device

 .../input/touchscreen/wacom,generic.yaml      |  66 ++++++
 .../devicetree/bindings/vendor-prefixes.yaml  |   2 +
 arch/arm/boot/dts/imx7d-remarkable2.dts       |  61 ++++++
 arch/arm/configs/imx_v6_v7_defconfig          |   1 +
 drivers/input/touchscreen/wacom_i2c.c         | 203 ++++++++++++++----
 5 files changed, 297 insertions(+), 36 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/input/touchscreen/wacom,generic.yaml

On Thu, Aug 19, 2021 at 01:49:33AM +1000, Alistair Francis wrote:
> Allow the device tree properties to flip the tilx, position or distance
> values.
> 
> This is required for the stylus to work correctly on the reMarkable 2.
> 
> Signed-off-by: Alistair Francis <alistair@alistair23.me>
> ---
>  .../input/touchscreen/wacom,generic.yaml      | 18 ++++++++++
>  drivers/input/touchscreen/wacom_i2c.c         | 33 +++++++++++++++++++
>  2 files changed, 51 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/input/touchscreen/wacom,generic.yaml b/Documentation/devicetree/bindings/input/touchscreen/wacom,generic.yaml
> index a8a7f362b0ce..0da63fd92ea1 100644
> --- a/Documentation/devicetree/bindings/input/touchscreen/wacom,generic.yaml
> +++ b/Documentation/devicetree/bindings/input/touchscreen/wacom,generic.yaml
> @@ -25,6 +25,24 @@ properties:
>    vdd-supply:
>      description: Power Supply
>  
> +  flip-tilt-x:
> +    type: boolean

These all need descriptions.

> +
> +  flip-tilt-y:
> +    type: boolean
> +
> +  flip-pos-x:
> +    type: boolean
> +
> +  flip-pos-y:
> +    type: boolean
> +
> +  flip-distance:
> +    type: boolean
> +
> +  flip-pressure:
> +    type: boolean

I don't understand how you flip pressure?

> +
>  required:
>    - compatible
>    - reg
> diff --git a/drivers/input/touchscreen/wacom_i2c.c b/drivers/input/touchscreen/wacom_i2c.c
> index c6579a1a8d04..82b62a768451 100644
> --- a/drivers/input/touchscreen/wacom_i2c.c
> +++ b/drivers/input/touchscreen/wacom_i2c.c
> @@ -72,6 +72,13 @@ struct wacom_i2c {
>  	u8 data[WACOM_QUERY_SIZE];
>  	bool prox;
>  	int tool;
> +
> +	bool flip_tilt_x;
> +	bool flip_tilt_y;
> +	bool flip_pos_x;
> +	bool flip_pos_y;
> +	bool flip_distance;
> +	bool flip_pressure;
>  };
>  
>  static int wacom_query_device(struct i2c_client *client,
> @@ -140,6 +147,20 @@ static int wacom_query_device(struct i2c_client *client,
>  	return 0;
>  }
>  
> +#ifdef CONFIG_OF


Use 'if (!IS_ENABLED(CONFIG_OF))' in the function and drop all the 
ifdefs.

> +static void wacom_of_read(struct wacom_i2c *wac_i2c)
> +{
> +	struct i2c_client *client = wac_i2c->client;
> +
> +	wac_i2c->flip_tilt_x = of_property_read_bool(client->dev.of_node, "flip-tilt-x");
> +	wac_i2c->flip_tilt_y = of_property_read_bool(client->dev.of_node, "flip-tilt-y");
> +	wac_i2c->flip_pos_x = of_property_read_bool(client->dev.of_node, "flip-pos-x");
> +	wac_i2c->flip_pos_y = of_property_read_bool(client->dev.of_node, "flip-pos-y");
> +	wac_i2c->flip_distance = of_property_read_bool(client->dev.of_node, "flip-distance");
> +	wac_i2c->flip_pressure = of_property_read_bool(client->dev.of_node, "flip-pressure");
> +}
> +#endif
> +
>  static irqreturn_t wacom_i2c_irq(int irq, void *dev_id)
>  {
>  	struct wacom_i2c *wac_i2c = dev_id;
> @@ -176,6 +197,14 @@ static irqreturn_t wacom_i2c_irq(int irq, void *dev_id)
>  
>  	wac_i2c->prox = data[3] & 0x20;
>  
> +	// Flip the values based on properties from the device tree
> +	pressure = wac_i2c->flip_pressure ? (features->pressure_max - pressure) : pressure;
> +	distance = wac_i2c->flip_distance ? -distance : distance;
> +	x = wac_i2c->flip_pos_x ? (features->x_max - x) : x;
> +	y = wac_i2c->flip_pos_y ? (features->y_max - y) : y;
> +	tilt_x = wac_i2c->flip_tilt_x ? -tilt_x : tilt_x;
> +	tilt_y = wac_i2c->flip_tilt_y ? -tilt_y : tilt_y;
> +
>  	touchscreen_report_pos(input, &wac_i2c->props, features->x_max,
>  			       features->y_max, true);
>  	input_report_key(input, BTN_TOUCH, tsw || ers);
> @@ -303,6 +332,10 @@ static int wacom_i2c_probe(struct i2c_client *client,
>  		return error;
>  	}
>  
> +#ifdef CONFIG_OF
> +	wacom_of_read(wac_i2c);
> +#endif
> +
>  	return 0;
>  }
>  
> -- 
> 2.31.1
> 
>