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

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

[Alistair Francis]

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

-- 
2.31.1

[PATCH v9 01/11] dt-bindings: Add Wacom to vendor bindings

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair@alistair23.me>
Acked-by: Rob Herring <robh@kernel.org>
Cc: devicetree@vger.kernel.org
---
 Documentation/devicetree/bindings/vendor-prefixes.yaml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
index 4dfaae537daf..31745c45dd92 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
+++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
@@ -1252,6 +1252,8 @@ patternProperties:
     description: Vision Optical Technology Co., Ltd.
   "^vxt,.*":
     description: VXT Ltd
+  "^wacom,.*":
+    description: Wacom Co., Ltd
   "^wand,.*":
     description: Wandbord (Technexion)
   "^waveshare,.*":
-- 
2.31.1

[PATCH v9 02/11] dt-bindings: touchscreen: Initial commit of wacom,i2c

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair@alistair23.me>
Reviewed-by: Rob Herring <robh@kernel.org>
Cc: devicetree@vger.kernel.org
---
 .../input/touchscreen/wacom,generic.yaml      | 48 +++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/touchscreen/wacom,generic.yaml

diff --git a/Documentation/devicetree/bindings/input/touchscreen/wacom,generic.yaml b/Documentation/devicetree/bindings/input/touchscreen/wacom,generic.yaml
new file mode 100644
index 000000000000..a8a7f362b0ce
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/wacom,generic.yaml
@@ -0,0 +1,48 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/touchscreen/wacom,generic.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Wacom I2C Controller
+
+maintainers:
+  - Alistair Francis <alistair@alistair23.me>
+
+allOf:
+  - $ref: touchscreen.yaml#
+
+properties:
+  compatible:
+    const: wacom,i2c-30
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  vdd-supply:
+    description: Power Supply
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include "dt-bindings/interrupt-controller/irq.h"
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        digitiser@9 {
+                compatible = "wacom,i2c-30";
+                reg = <0x9>;
+                interrupt-parent = <&gpio1>;
+                interrupts = <9 IRQ_TYPE_LEVEL_LOW>;
+                vdd-supply = <&reg_touch>;
+        };
+    };
-- 
2.31.1

[PATCH v9 03/11] Input: wacom_i2c - Add device tree support to wacom_i2c

[Alistair Francis]

Allow the wacom-i2c device to be exposed via device tree.

Signed-off-by: Alistair Francis <alistair@alistair23.me>
---
 drivers/input/touchscreen/wacom_i2c.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/input/touchscreen/wacom_i2c.c b/drivers/input/touchscreen/wacom_i2c.c
index 22826c387da5..6053595f2b30 100644
--- a/drivers/input/touchscreen/wacom_i2c.c
+++ b/drivers/input/touchscreen/wacom_i2c.c
@@ -12,6 +12,7 @@
 #include <linux/slab.h>
 #include <linux/irq.h>
 #include <linux/interrupt.h>
+#include <linux/of.h>
 #include <asm/unaligned.h>
 
 #define WACOM_CMD_QUERY0	0x04
@@ -241,10 +242,17 @@ static const struct i2c_device_id wacom_i2c_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, wacom_i2c_id);
 
+static const struct of_device_id wacom_i2c_of_match_table[] = {
+	{ .compatible = "wacom,i2c-30" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, wacom_i2c_of_match_table);
+
 static struct i2c_driver wacom_i2c_driver = {
 	.driver	= {
 		.name	= "wacom_i2c",
 		.pm	= &wacom_i2c_pm,
+		.of_match_table = wacom_i2c_of_match_table,
 	},
 
 	.probe		= wacom_i2c_probe,
-- 
2.31.1

[PATCH v9 04/11] Input: wacom_i2c - Add touchscren properties

[Alistair Francis]

Connect touchscreen properties to the wacom_i2c.

Signed-off-by: Alistair Francis <alistair@alistair23.me>
---
 drivers/input/touchscreen/wacom_i2c.c | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/drivers/input/touchscreen/wacom_i2c.c b/drivers/input/touchscreen/wacom_i2c.c
index 6053595f2b30..28255c77d426 100644
--- a/drivers/input/touchscreen/wacom_i2c.c
+++ b/drivers/input/touchscreen/wacom_i2c.c
@@ -11,6 +11,7 @@
 #include <linux/i2c.h>
 #include <linux/slab.h>
 #include <linux/irq.h>
+#include <linux/input/touchscreen.h>
 #include <linux/interrupt.h>
 #include <linux/of.h>
 #include <asm/unaligned.h>
@@ -33,6 +34,8 @@ struct wacom_features {
 struct wacom_i2c {
 	struct i2c_client *client;
 	struct input_dev *input;
+	struct touchscreen_properties props;
+	struct wacom_features features;
 	u8 data[WACOM_QUERY_SIZE];
 	bool prox;
 	int tool;
@@ -90,6 +93,7 @@ static irqreturn_t wacom_i2c_irq(int irq, void *dev_id)
 {
 	struct wacom_i2c *wac_i2c = dev_id;
 	struct input_dev *input = wac_i2c->input;
+	struct wacom_features *features = &wac_i2c->features;
 	u8 *data = wac_i2c->data;
 	unsigned int x, y, pressure;
 	unsigned char tsw, f1, f2, ers;
@@ -114,6 +118,8 @@ static irqreturn_t wacom_i2c_irq(int irq, void *dev_id)
 
 	wac_i2c->prox = data[3] & 0x20;
 
+	touchscreen_report_pos(input, &wac_i2c->props, features->x_max,
+			       features->y_max, true);
 	input_report_key(input, BTN_TOUCH, tsw || ers);
 	input_report_key(input, wac_i2c->tool, wac_i2c->prox);
 	input_report_key(input, BTN_STYLUS, f1);
@@ -151,7 +157,7 @@ static int wacom_i2c_probe(struct i2c_client *client,
 	struct device *dev = &client->dev;
 	struct wacom_i2c *wac_i2c;
 	struct input_dev *input;
-	struct wacom_features features = { 0 };
+	struct wacom_features *features;
 	int error;
 
 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
@@ -159,14 +165,15 @@ static int wacom_i2c_probe(struct i2c_client *client,
 		return -EIO;
 	}
 
-	error = wacom_query_device(client, &features);
-	if (error)
-		return error;
-
 	wac_i2c = devm_kzalloc(dev, sizeof(*wac_i2c), GFP_KERNEL);
 	if (!wac_i2c)
 		return -ENOMEM;
 
+	features = &wac_i2c->features;
+	error = wacom_query_device(client, features);
+	if (error)
+		return error;
+
 	wac_i2c->client = client;
 
 	input = devm_input_allocate_device(dev);
@@ -178,7 +185,7 @@ static int wacom_i2c_probe(struct i2c_client *client,
 	input->name = "Wacom I2C Digitizer";
 	input->id.bustype = BUS_I2C;
 	input->id.vendor = 0x56a;
-	input->id.version = features.fw_version;
+	input->id.version = features->fw_version;
 	input->open = wacom_i2c_open;
 	input->close = wacom_i2c_close;
 
@@ -190,10 +197,11 @@ static int wacom_i2c_probe(struct i2c_client *client,
 	__set_bit(BTN_STYLUS2, input->keybit);
 	__set_bit(BTN_TOUCH, input->keybit);
 
-	input_set_abs_params(input, ABS_X, 0, features.x_max, 0, 0);
-	input_set_abs_params(input, ABS_Y, 0, features.y_max, 0, 0);
+	touchscreen_parse_properties(input, true, &wac_i2c->props);
+	input_set_abs_params(input, ABS_X, 0, features->x_max, 0, 0);
+	input_set_abs_params(input, ABS_Y, 0, features->y_max, 0, 0);
 	input_set_abs_params(input, ABS_PRESSURE,
-			     0, features.pressure_max, 0, 0);
+			     0, features->pressure_max, 0, 0);
 
 	input_set_drvdata(input, wac_i2c);
 
-- 
2.31.1

[PATCH v9 05/11] Input: wacom_i2c - Add support for distance and tilt x/y

[Alistair Francis]

Add support for the distance and tilt x/y.

This is based on the out of tree rM2 driver.

Signed-off-by: Alistair Francis <alistair@alistair23.me>
---
 drivers/input/touchscreen/wacom_i2c.c | 35 +++++++++++++++++++++++++--
 1 file changed, 33 insertions(+), 2 deletions(-)

diff --git a/drivers/input/touchscreen/wacom_i2c.c b/drivers/input/touchscreen/wacom_i2c.c
index 28255c77d426..4d0c19fbada4 100644
--- a/drivers/input/touchscreen/wacom_i2c.c
+++ b/drivers/input/touchscreen/wacom_i2c.c
@@ -22,12 +22,18 @@
 #define WACOM_CMD_QUERY3	0x02
 #define WACOM_CMD_THROW0	0x05
 #define WACOM_CMD_THROW1	0x00
-#define WACOM_QUERY_SIZE	19
+#define WACOM_QUERY_SIZE	22
+
+#define WACOM_DISTANCE_TILT_VERSION	0x30
 
 struct wacom_features {
 	int x_max;
 	int y_max;
 	int pressure_max;
+	int distance_max;
+	int distance_physical_max;
+	int tilt_x_max;
+	int tilt_y_max;
 	char fw_version;
 };
 
@@ -80,6 +86,17 @@ static int wacom_query_device(struct i2c_client *client,
 	features->y_max = get_unaligned_le16(&data[5]);
 	features->pressure_max = get_unaligned_le16(&data[11]);
 	features->fw_version = get_unaligned_le16(&data[13]);
+	if (features->fw_version >= WACOM_DISTANCE_TILT_VERSION) {
+		features->distance_max = data[15];
+		features->distance_physical_max = data[16];
+		features->tilt_x_max = get_unaligned_le16(&data[17]);
+		features->tilt_y_max = get_unaligned_le16(&data[19]);
+	} else {
+		features->distance_max = -1;
+		features->distance_physical_max = -1;
+		features->tilt_x_max = -1;
+		features->tilt_y_max = -1;
+	}
 
 	dev_dbg(&client->dev,
 		"x_max:%d, y_max:%d, pressure:%d, fw:%d\n",
@@ -97,6 +114,7 @@ static irqreturn_t wacom_i2c_irq(int irq, void *dev_id)
 	u8 *data = wac_i2c->data;
 	unsigned int x, y, pressure;
 	unsigned char tsw, f1, f2, ers;
+	short tilt_x, tilt_y, distance;
 	int error;
 
 	error = i2c_master_recv(wac_i2c->client,
@@ -112,6 +130,12 @@ static irqreturn_t wacom_i2c_irq(int irq, void *dev_id)
 	y = le16_to_cpup((__le16 *)&data[6]);
 	pressure = le16_to_cpup((__le16 *)&data[8]);
 
+	/* Signed */
+	tilt_x = le16_to_cpup((__le16 *)&data[11]);
+	tilt_y = le16_to_cpup((__le16 *)&data[13]);
+
+	distance = le16_to_cpup((__le16 *)&data[15]);
+
 	if (!wac_i2c->prox)
 		wac_i2c->tool = (data[3] & 0x0c) ?
 			BTN_TOOL_RUBBER : BTN_TOOL_PEN;
@@ -127,6 +151,9 @@ static irqreturn_t wacom_i2c_irq(int irq, void *dev_id)
 	input_report_abs(input, ABS_X, x);
 	input_report_abs(input, ABS_Y, y);
 	input_report_abs(input, ABS_PRESSURE, pressure);
+	input_report_abs(input, ABS_DISTANCE, distance);
+	input_report_abs(input, ABS_TILT_X, tilt_x);
+	input_report_abs(input, ABS_TILT_Y, tilt_y);
 	input_sync(input);
 
 out:
@@ -202,7 +229,11 @@ static int wacom_i2c_probe(struct i2c_client *client,
 	input_set_abs_params(input, ABS_Y, 0, features->y_max, 0, 0);
 	input_set_abs_params(input, ABS_PRESSURE,
 			     0, features->pressure_max, 0, 0);
-
+	input_set_abs_params(input, ABS_DISTANCE, 0, features->distance_max, 0, 0);
+	input_set_abs_params(input, ABS_TILT_X, -features->tilt_x_max,
+			     features->tilt_x_max, 0, 0);
+	input_set_abs_params(input, ABS_TILT_Y, -features->tilt_y_max,
+			     features->tilt_y_max, 0, 0);
 	input_set_drvdata(input, wac_i2c);
 
 	error = devm_request_threaded_irq(dev, client->irq, NULL, wacom_i2c_irq,
-- 
2.31.1

Re: [PATCH v9 05/11] Input: wacom_i2c - Add support for distance and tilt x/y

[Ahmad Fatoum]

On 18.08.21 17:49, Alistair Francis wrote:
> Add support for the distance and tilt x/y.
> 
> This is based on the out of tree rM2 driver.
> 
> Signed-off-by: Alistair Francis <alistair@alistair23.me>
> ---
>  drivers/input/touchscreen/wacom_i2c.c | 35 +++++++++++++++++++++++++--
>  1 file changed, 33 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/input/touchscreen/wacom_i2c.c b/drivers/input/touchscreen/wacom_i2c.c
> index 28255c77d426..4d0c19fbada4 100644
> --- a/drivers/input/touchscreen/wacom_i2c.c
> +++ b/drivers/input/touchscreen/wacom_i2c.c

> +	/* Signed */
> +	tilt_x = le16_to_cpup((__le16 *)&data[11]);
> +	tilt_y = le16_to_cpup((__le16 *)&data[13]);
> +
> +	distance = le16_to_cpup((__le16 *)&data[15]);

Use get_unaligned_u16 for all three. The existing code doesn't need to do this,
because with the current struct layout, the array is suitable aligned
for 2 byte accesses. You are accessing data at odd indices though, so you
need to use an unaligned accessor.

Cheers,
Ahmad

> +
>  	if (!wac_i2c->prox)
>  		wac_i2c->tool = (data[3] & 0x0c) ?
>  			BTN_TOOL_RUBBER : BTN_TOOL_PEN;
> @@ -127,6 +151,9 @@ static irqreturn_t wacom_i2c_irq(int irq, void *dev_id)
>  	input_report_abs(input, ABS_X, x);
>  	input_report_abs(input, ABS_Y, y);
>  	input_report_abs(input, ABS_PRESSURE, pressure);
> +	input_report_abs(input, ABS_DISTANCE, distance);
> +	input_report_abs(input, ABS_TILT_X, tilt_x);
> +	input_report_abs(input, ABS_TILT_Y, tilt_y);
>  	input_sync(input);
>  
>  out:
> @@ -202,7 +229,11 @@ static int wacom_i2c_probe(struct i2c_client *client,
>  	input_set_abs_params(input, ABS_Y, 0, features->y_max, 0, 0);
>  	input_set_abs_params(input, ABS_PRESSURE,
>  			     0, features->pressure_max, 0, 0);
> -
> +	input_set_abs_params(input, ABS_DISTANCE, 0, features->distance_max, 0, 0);
> +	input_set_abs_params(input, ABS_TILT_X, -features->tilt_x_max,
> +			     features->tilt_x_max, 0, 0);
> +	input_set_abs_params(input, ABS_TILT_Y, -features->tilt_y_max,
> +			     features->tilt_y_max, 0, 0);
>  	input_set_drvdata(input, wac_i2c);
>  
>  	error = devm_request_threaded_irq(dev, client->irq, NULL, wacom_i2c_irq,
> 


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[PATCH v9 06/11] Input: wacom_i2c - Clean up the query device fields

[Alistair Francis]

Improve the query device fields to be more verbose.

Signed-off-by: Alistair Francis <alistair@alistair23.me>
---
 drivers/input/touchscreen/wacom_i2c.c | 64 ++++++++++++++++++---------
 1 file changed, 44 insertions(+), 20 deletions(-)

diff --git a/drivers/input/touchscreen/wacom_i2c.c b/drivers/input/touchscreen/wacom_i2c.c
index 4d0c19fbada4..33a3ba110171 100644
--- a/drivers/input/touchscreen/wacom_i2c.c
+++ b/drivers/input/touchscreen/wacom_i2c.c
@@ -13,15 +13,32 @@
 #include <linux/irq.h>
 #include <linux/input/touchscreen.h>
 #include <linux/interrupt.h>
+#include <linux/reset.h>
 #include <linux/of.h>
 #include <asm/unaligned.h>
 
-#define WACOM_CMD_QUERY0	0x04
-#define WACOM_CMD_QUERY1	0x00
-#define WACOM_CMD_QUERY2	0x33
-#define WACOM_CMD_QUERY3	0x02
-#define WACOM_CMD_THROW0	0x05
-#define WACOM_CMD_THROW1	0x00
+// Registers
+#define WACOM_COMMAND_LSB   0x04
+#define WACOM_COMMAND_MSB   0x00
+
+#define WACOM_DATA_LSB      0x05
+#define WACOM_DATA_MSB      0x00
+
+// Report types
+#define REPORT_FEATURE      0x30
+
+// Requests / operations
+#define OPCODE_GET_REPORT   0x02
+
+// Power settings
+#define POWER_ON            0x00
+#define POWER_SLEEP         0x01
+
+// Input report ids
+#define WACOM_PEN_DATA_REPORT           2
+#define WACOM_SHINONOME_REPORT          26
+
+#define WACOM_QUERY_REPORT	3
 #define WACOM_QUERY_SIZE	22
 
 #define WACOM_DISTANCE_TILT_VERSION	0x30
@@ -51,27 +68,30 @@ static int wacom_query_device(struct i2c_client *client,
 			      struct wacom_features *features)
 {
 	int ret;
-	u8 cmd1[] = { WACOM_CMD_QUERY0, WACOM_CMD_QUERY1,
-			WACOM_CMD_QUERY2, WACOM_CMD_QUERY3 };
-	u8 cmd2[] = { WACOM_CMD_THROW0, WACOM_CMD_THROW1 };
 	u8 data[WACOM_QUERY_SIZE];
+
+	u8 get_query_data_cmd[] = {
+		WACOM_COMMAND_LSB,
+		WACOM_COMMAND_MSB,
+		REPORT_FEATURE | WACOM_QUERY_REPORT,
+		OPCODE_GET_REPORT,
+		WACOM_DATA_LSB,
+		WACOM_DATA_MSB,
+	};
+
 	struct i2c_msg msgs[] = {
+		// Request reading of feature ReportID: 3 (Pen Query Data)
 		{
 			.addr = client->addr,
 			.flags = 0,
-			.len = sizeof(cmd1),
-			.buf = cmd1,
-		},
-		{
-			.addr = client->addr,
-			.flags = 0,
-			.len = sizeof(cmd2),
-			.buf = cmd2,
+			.len = sizeof(get_query_data_cmd),
+			.buf = get_query_data_cmd,
 		},
+		// Read 21 bytes
 		{
 			.addr = client->addr,
 			.flags = I2C_M_RD,
-			.len = sizeof(data),
+			.len = WACOM_QUERY_SIZE - 1,
 			.buf = data,
 		},
 	};
@@ -99,9 +119,13 @@ static int wacom_query_device(struct i2c_client *client,
 	}
 
 	dev_dbg(&client->dev,
-		"x_max:%d, y_max:%d, pressure:%d, fw:%d\n",
+		"x_max:%d, y_max:%d, pressure:%d, fw:%d, "
+		"distance: %d, phys distance: %d, "
+		"tilt_x_max: %d, tilt_y_max: %d\n",
 		features->x_max, features->y_max,
-		features->pressure_max, features->fw_version);
+		features->pressure_max, features->fw_version,
+		features->distance_max, features->distance_physical_max,
+		features->tilt_x_max, features->tilt_y_max);
 
 	return 0;
 }
-- 
2.31.1

[PATCH v9 07/11] Input: wacom_i2c - Add support for vdd regulator

[Alistair Francis]

Add support for a VDD regulator. This allows the kernel to probe the
Wacom-I2C device on the rM2.

Signed-off-by: Alistair Francis <alistair@alistair23.me>
---
 drivers/input/touchscreen/wacom_i2c.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/input/touchscreen/wacom_i2c.c b/drivers/input/touchscreen/wacom_i2c.c
index 33a3ba110171..fd486b8ef2cc 100644
--- a/drivers/input/touchscreen/wacom_i2c.c
+++ b/drivers/input/touchscreen/wacom_i2c.c
@@ -13,6 +13,7 @@
 #include <linux/irq.h>
 #include <linux/input/touchscreen.h>
 #include <linux/interrupt.h>
+#include <linux/regulator/consumer.h>
 #include <linux/reset.h>
 #include <linux/of.h>
 #include <asm/unaligned.h>
@@ -59,6 +60,7 @@ struct wacom_i2c {
 	struct input_dev *input;
 	struct touchscreen_properties props;
 	struct wacom_features features;
+	struct regulator *vdd;
 	u8 data[WACOM_QUERY_SIZE];
 	bool prox;
 	int tool;
@@ -220,6 +222,16 @@ static int wacom_i2c_probe(struct i2c_client *client,
 	if (!wac_i2c)
 		return -ENOMEM;
 
+	wac_i2c->vdd = regulator_get(&client->dev, "vdd");
+	if (IS_ERR(wac_i2c->vdd))
+		return PTR_ERR(wac_i2c->vdd);
+
+	error = regulator_enable(wac_i2c->vdd);
+	if (error) {
+		regulator_put(wac_i2c->vdd);
+		return error;
+	}
+
 	features = &wac_i2c->features;
 	error = wacom_query_device(client, features);
 	if (error)
@@ -228,8 +240,11 @@ static int wacom_i2c_probe(struct i2c_client *client,
 	wac_i2c->client = client;
 
 	input = devm_input_allocate_device(dev);
-	if (!input)
+	if (!input) {
+		regulator_disable(wac_i2c->vdd);
+		regulator_put(wac_i2c->vdd);
 		return -ENOMEM;
+	}
 
 	wac_i2c->input = input;
 
@@ -264,6 +279,8 @@ static int wacom_i2c_probe(struct i2c_client *client,
 					  IRQF_ONESHOT, "wacom_i2c", wac_i2c);
 	if (error) {
 		dev_err(dev, "Failed to request IRQ: %d\n", error);
+		regulator_disable(wac_i2c->vdd);
+		regulator_put(wac_i2c->vdd);
 		return error;
 	}
 
@@ -273,6 +290,8 @@ static int wacom_i2c_probe(struct i2c_client *client,
 	error = input_register_device(wac_i2c->input);
 	if (error) {
 		dev_err(dev, "Failed to register input device: %d\n", error);
+		regulator_disable(wac_i2c->vdd);
+		regulator_put(wac_i2c->vdd);
 		return error;
 	}
 
-- 
2.31.1

[PATCH v9 08/11] Input: wacom_i2c - Use macros for the bit masks

[Alistair Francis]

To make the code easier to read use macros for the bit masks.

Signed-off-by: Alistair Francis <alistair@alistair23.me>
---
 drivers/input/touchscreen/wacom_i2c.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/input/touchscreen/wacom_i2c.c b/drivers/input/touchscreen/wacom_i2c.c
index fd486b8ef2cc..c6579a1a8d04 100644
--- a/drivers/input/touchscreen/wacom_i2c.c
+++ b/drivers/input/touchscreen/wacom_i2c.c
@@ -18,6 +18,14 @@
 #include <linux/of.h>
 #include <asm/unaligned.h>
 
+// Bitmasks (for data[3])
+#define WACOM_TIP_SWITCH_bm         (1 << 0)
+#define WACOM_BARREL_SWITCH_bm      (1 << 1)
+#define WACOM_ERASER_bm             (1 << 2)
+#define WACOM_INVERT_bm             (1 << 3)
+#define WACOM_BARREL_SWITCH_2_bm    (1 << 4)
+#define WACOM_IN_RANGE_bm           (1 << 5)
+
 // Registers
 #define WACOM_COMMAND_LSB   0x04
 #define WACOM_COMMAND_MSB   0x00
@@ -148,10 +156,10 @@ static irqreturn_t wacom_i2c_irq(int irq, void *dev_id)
 	if (error < 0)
 		goto out;
 
-	tsw = data[3] & 0x01;
-	ers = data[3] & 0x04;
-	f1 = data[3] & 0x02;
-	f2 = data[3] & 0x10;
+	tsw = data[3] & WACOM_TIP_SWITCH_bm;
+	ers = data[3] & WACOM_ERASER_bm;
+	f1 = data[3] & WACOM_BARREL_SWITCH_bm;
+	f2 = data[3] & WACOM_BARREL_SWITCH_2_bm;
 	x = le16_to_cpup((__le16 *)&data[4]);
 	y = le16_to_cpup((__le16 *)&data[6]);
 	pressure = le16_to_cpup((__le16 *)&data[8]);
-- 
2.31.1

[PATCH v9 09/11] Input: wacom_i2c - Allow flipping the values from the DT

[Alistair Francis]

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

Re: [PATCH v9 09/11] Input: wacom_i2c - Allow flipping the values from the DT

[Rob Herring]

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
> 
> 

[PATCH v9 10/11] ARM: imx_v6_v7_defconfig: Enable Wacom I2C

[Alistair Francis]

Enable the Wacom I2C in the imx defconfig as it is used by the
reMarkable2 tablet.

Signed-off-by: Alistair Francis <alistair@alistair23.me>
---
 arch/arm/configs/imx_v6_v7_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/imx_v6_v7_defconfig b/arch/arm/configs/imx_v6_v7_defconfig
index 079fcd8d1d11..477dac1edc75 100644
--- a/arch/arm/configs/imx_v6_v7_defconfig
+++ b/arch/arm/configs/imx_v6_v7_defconfig
@@ -176,6 +176,7 @@ CONFIG_TOUCHSCREEN_DA9052=y
 CONFIG_TOUCHSCREEN_EGALAX=y
 CONFIG_TOUCHSCREEN_GOODIX=y
 CONFIG_TOUCHSCREEN_ILI210X=y
+CONFIG_TOUCHSCREEN_WACOM_I2C=y
 CONFIG_TOUCHSCREEN_MAX11801=y
 CONFIG_TOUCHSCREEN_IMX6UL_TSC=y
 CONFIG_TOUCHSCREEN_EDT_FT5X06=y
-- 
2.31.1

[PATCH v9 11/11] ARM: dts: imx7d: remarkable2: add wacom digitizer device

[Alistair Francis]

Enable the wacom_i2c touchscreen for the reMarkable2.

Signed-off-by: Alistair Francis <alistair@alistair23.me>
---
 arch/arm/boot/dts/imx7d-remarkable2.dts | 61 +++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/arch/arm/boot/dts/imx7d-remarkable2.dts b/arch/arm/boot/dts/imx7d-remarkable2.dts
index 89cbf13097a4..052f9da32398 100644
--- a/arch/arm/boot/dts/imx7d-remarkable2.dts
+++ b/arch/arm/boot/dts/imx7d-remarkable2.dts
@@ -34,6 +34,19 @@ reg_brcm: regulator-brcm {
 		startup-delay-us = <150>;
 	};
 
+	reg_digitizer: regulator-digitizer {
+		compatible = "regulator-fixed";
+		regulator-name = "VDD_3V3_DIGITIZER";
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+		pinctrl-names = "default", "sleep";
+		pinctrl-0 = <&pinctrl_digitizer_reg>;
+		pinctrl-1 = <&pinctrl_digitizer_reg>;
+		gpio = <&gpio1 6 GPIO_ACTIVE_HIGH>;
+		enable-active-high;
+		startup-delay-us = <100000>; /* 100 ms */
+	};
+
 	wifi_pwrseq: wifi_pwrseq {
 		compatible = "mmc-pwrseq-simple";
 		pinctrl-names = "default";
@@ -51,6 +64,28 @@ &clks {
 	assigned-clock-rates = <0>, <32768>;
 };
 
+&i2c1 {
+	clock-frequency = <400000>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_i2c1>;
+	status = "okay";
+
+	wacom_digitizer: digitizer@9 {
+		compatible = "wacom,i2c-30";
+		reg = <0x09>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&pinctrl_wacom>;
+		interrupt-parent = <&gpio1>;
+		interrupts = <1 IRQ_TYPE_LEVEL_LOW>;
+		flip-tilt-x;
+		flip-tilt-y;
+		flip-pos-x;
+		flip-pos-y;
+		flip-distance;
+		vdd-supply = <&reg_digitizer>;
+	};
+};
+
 &snvs_pwrkey {
 	status = "okay";
 };
@@ -117,6 +152,25 @@ &wdog1 {
 	fsl,ext-reset-output;
 };
 
+&iomuxc_lpsr {
+	pinctrl_digitizer_reg: digitizerreggrp {
+		fsl,pins = <
+			/* DIGITIZER_PWR_EN */
+			MX7D_PAD_LPSR_GPIO1_IO06__GPIO1_IO6	0x14
+		>;
+	};
+
+	pinctrl_wacom: wacomgrp {
+		fsl,pins = <
+			/*MX7D_PAD_LPSR_GPIO1_IO05__GPIO1_IO5	0x00000014 /* FWE */
+			MX7D_PAD_LPSR_GPIO1_IO04__GPIO1_IO4	0x00000074 /* PDCTB */
+			MX7D_PAD_LPSR_GPIO1_IO01__GPIO1_IO1	0x00000034 /* WACOM INT */
+			/*MX7D_PAD_LPSR_GPIO1_IO06__GPIO1_IO6	0x00000014 /* WACOM PWR ENABLE */
+			/*MX7D_PAD_LPSR_GPIO1_IO00__GPIO1_IO0	0x00000074 /* WACOM RESET */
+		>;
+	};
+};
+
 &iomuxc {
 	pinctrl_brcm_reg: brcmreggrp {
 		fsl,pins = <
@@ -125,6 +179,13 @@ MX7D_PAD_SAI1_TX_BCLK__GPIO6_IO13	0x14
 		>;
 	};
 
+	pinctrl_i2c1: i2c1grp {
+		fsl,pins = <
+			MX7D_PAD_I2C1_SDA__I2C1_SDA		0x4000007f
+			MX7D_PAD_I2C1_SCL__I2C1_SCL		0x4000007f
+		>;
+	};
+
 	pinctrl_uart1: uart1grp {
 		fsl,pins = <
 			MX7D_PAD_UART1_TX_DATA__UART1_DCE_TX	0x79
-- 
2.31.1