[PATCH v4 0/5] input/touchscreen: imagis: add support for IST3032C

[PATCH v4 0/5] input/touchscreen: imagis: add support for IST3032C

[Karel Balej]

From: Karel Balej <balejk@matfyz.cz>

Hello,

this patch series generalizes the Imagis touchscreen driver to support
other Imagis chips, namely IST3038B and IST3032C, which use a slightly
different protocol.

It also adds necessary information to the driver so that the IST3032C
touchscreen can be used with it. The motivation for this is the
samsung,coreprimevelte smartphone with which this series has been
tested. However, the support for this device is not yet in-tree, the
effort is happening at [1]. Preliminary version of the regulator driver
needed to use the touchscreen on this phone can be found here [2].

Note that this is a prerequisite for this patch [3] which implements
support for touch keys for Imagis touchscreens that have it.

[1] https://lore.kernel.org/all/20240110-pxa1908-lkml-v8-0-fea768a59474@skole.hr/
[2] https://lore.kernel.org/all/20231228100208.2932-1-karelb@gimli.ms.mff.cuni.cz/
[3] https://lore.kernel.org/all/20231112194124.24916-1-duje.mihanovic@skole.hr/
---
v4:
- Rebase to v6.7.
- v3: https://lore.kernel.org/all/20231202125948.10345-1-karelb@gimli.ms.mff.cuni.cz/
- Address feedback and add trailers.
v3:
- Rebase to v6.7-rc3.
- v2: https://lore.kernel.org/all/20231003133440.4696-1-karelb@gimli.ms.mff.cuni.cz/
v2:
- Do not rename the driver.
- Do not hardcode voltage required by the IST3032C.
- Use Markuss' series which generalizes the driver. Link to the original
  series: https://lore.kernel.org/all/20220504152406.8730-1-markuss.broks@gmail.com/
- Separate bindings into separate patch.
- v1: https://lore.kernel.org/all/20230926173531.18715-1-balejk@matfyz.cz/

Karel Balej (2):
  dt-bindings: input/touchscreen: imagis: add compatible for IST3032C
  input/touchscreen: imagis: add support for IST3032C

Markuss Broks (3):
  input/touchscreen: imagis: Correct the maximum touch area value
  dt-bindings: input/touchscreen: Add compatible for IST3038B
  input/touchscreen: imagis: Add support for Imagis IST3038B

 .../input/touchscreen/imagis,ist3038c.yaml    |  2 +
 drivers/input/touchscreen/imagis.c            | 70 +++++++++++++++----
 2 files changed, 60 insertions(+), 12 deletions(-)

-- 
2.43.0

[PATCH v4 1/5] input/touchscreen: imagis: Correct the maximum touch area value

[Karel Balej]

From: Markuss Broks <markuss.broks@gmail.com>

As specified in downstream IST3038B driver and proved by testing,
the correct maximum reported value of touch area is 16.

Signed-off-by: Markuss Broks <markuss.broks@gmail.com>
Signed-off-by: Karel Balej <balejk@matfyz.cz>
---
 drivers/input/touchscreen/imagis.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/input/touchscreen/imagis.c b/drivers/input/touchscreen/imagis.c
index 07111ca24455..e67fd3011027 100644
--- a/drivers/input/touchscreen/imagis.c
+++ b/drivers/input/touchscreen/imagis.c
@@ -210,7 +210,7 @@ static int imagis_init_input_dev(struct imagis_ts *ts)
 
 	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X);
 	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y);
-	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
+	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0, 16, 0, 0);
 
 	touchscreen_parse_properties(input_dev, true, &ts->prop);
 	if (!ts->prop.max_x || !ts->prop.max_y) {
-- 
2.43.0

[PATCH v4 2/5] dt-bindings: input/touchscreen: Add compatible for IST3038B

[Karel Balej]

From: Markuss Broks <markuss.broks@gmail.com>

Imagis IST3038B is a variant (firmware?) of Imagis IST3038 IC
differing from IST3038C in its register interface. Add the
compatible for it to the IST3038C bindings.

Signed-off-by: Markuss Broks <markuss.broks@gmail.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
[balejk@matfyz.cz: elaborate chip differences in the commit message]
Signed-off-by: Karel Balej <balejk@matfyz.cz>
---

Notes:
    v4:
    * Mention how the chip is different in terms of the programming model in
      the commit message.
    * Add Conor's trailer.

 .../devicetree/bindings/input/touchscreen/imagis,ist3038c.yaml   | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/input/touchscreen/imagis,ist3038c.yaml b/Documentation/devicetree/bindings/input/touchscreen/imagis,ist3038c.yaml
index 0d6b033fd5fb..b5372c4eae56 100644
--- a/Documentation/devicetree/bindings/input/touchscreen/imagis,ist3038c.yaml
+++ b/Documentation/devicetree/bindings/input/touchscreen/imagis,ist3038c.yaml
@@ -18,6 +18,7 @@ properties:
 
   compatible:
     enum:
+      - imagis,ist3038b
       - imagis,ist3038c
 
   reg:
-- 
2.43.0

[PATCH v4 3/5] input/touchscreen: imagis: Add support for Imagis IST3038B

[Karel Balej]

From: Markuss Broks <markuss.broks@gmail.com>

Imagis IST3038B is another variant of Imagis IST3038 IC, which has
a different register interface from IST3038C (possibly firmware defined).
This should also work for IST3044B (though untested), however other
variants using this interface/protocol(IST3026, IST3032, IST3026B,
IST3032B) have a different format for coordinates, and they'd need
additional effort to be supported by this driver.

Signed-off-by: Markuss Broks <markuss.broks@gmail.com>
Signed-off-by: Karel Balej <balejk@matfyz.cz>
---

Notes:
    v4:
    * Sort the definitions in alphanumerical order.

 drivers/input/touchscreen/imagis.c | 58 ++++++++++++++++++++++++------
 1 file changed, 47 insertions(+), 11 deletions(-)

diff --git a/drivers/input/touchscreen/imagis.c b/drivers/input/touchscreen/imagis.c
index e67fd3011027..9af8a6332ae6 100644
--- a/drivers/input/touchscreen/imagis.c
+++ b/drivers/input/touchscreen/imagis.c
@@ -11,9 +11,13 @@
 #include <linux/property.h>
 #include <linux/regulator/consumer.h>
 
+#define IST3038B_REG_STATUS		0x20
+#define IST3038B_REG_CHIPID		0x30
+#define IST3038B_WHOAMI			0x30380b
+
 #define IST3038C_HIB_ACCESS		(0x800B << 16)
 #define IST3038C_DIRECT_ACCESS		BIT(31)
-#define IST3038C_REG_CHIPID		0x40001000
+#define IST3038C_REG_CHIPID		(0x40001000 | IST3038C_DIRECT_ACCESS)
 #define IST3038C_REG_HIB_BASE		0x30000100
 #define IST3038C_REG_TOUCH_STATUS	(IST3038C_REG_HIB_BASE | IST3038C_HIB_ACCESS)
 #define IST3038C_REG_TOUCH_COORD	(IST3038C_REG_HIB_BASE | IST3038C_HIB_ACCESS | 0x8)
@@ -31,8 +35,17 @@
 #define IST3038C_FINGER_COUNT_SHIFT	12
 #define IST3038C_FINGER_STATUS_MASK	GENMASK(9, 0)
 
+struct imagis_properties {
+	unsigned int interrupt_msg_cmd;
+	unsigned int touch_coord_cmd;
+	unsigned int whoami_cmd;
+	unsigned int whoami_val;
+	bool protocol_b;
+};
+
 struct imagis_ts {
 	struct i2c_client *client;
+	const struct imagis_properties *tdata;
 	struct input_dev *input_dev;
 	struct touchscreen_properties prop;
 	struct regulator_bulk_data supplies[2];
@@ -84,8 +97,7 @@ static irqreturn_t imagis_interrupt(int irq, void *dev_id)
 	int i;
 	int error;
 
-	error = imagis_i2c_read_reg(ts, IST3038C_REG_INTR_MESSAGE,
-				    &intr_message);
+	error = imagis_i2c_read_reg(ts, ts->tdata->interrupt_msg_cmd, &intr_message);
 	if (error) {
 		dev_err(&ts->client->dev,
 			"failed to read the interrupt message: %d\n", error);
@@ -104,9 +116,13 @@ static irqreturn_t imagis_interrupt(int irq, void *dev_id)
 	finger_pressed = intr_message & IST3038C_FINGER_STATUS_MASK;
 
 	for (i = 0; i < finger_count; i++) {
-		error = imagis_i2c_read_reg(ts,
-					    IST3038C_REG_TOUCH_COORD + (i * 4),
-					    &finger_status);
+		if (ts->tdata->protocol_b)
+			error = imagis_i2c_read_reg(ts,
+						    ts->tdata->touch_coord_cmd, &finger_status);
+		else
+			error = imagis_i2c_read_reg(ts,
+						    ts->tdata->touch_coord_cmd + (i * 4),
+						    &finger_status);
 		if (error) {
 			dev_err(&ts->client->dev,
 				"failed to read coordinates for finger %d: %d\n",
@@ -261,6 +277,12 @@ static int imagis_probe(struct i2c_client *i2c)
 
 	ts->client = i2c;
 
+	ts->tdata = device_get_match_data(dev);
+	if (!ts->tdata) {
+		dev_err(dev, "missing chip data\n");
+		return -EINVAL;
+	}
+
 	error = imagis_init_regulators(ts);
 	if (error) {
 		dev_err(dev, "regulator init error: %d\n", error);
@@ -279,15 +301,13 @@ static int imagis_probe(struct i2c_client *i2c)
 		return error;
 	}
 
-	error = imagis_i2c_read_reg(ts,
-			IST3038C_REG_CHIPID | IST3038C_DIRECT_ACCESS,
-			&chip_id);
+	error = imagis_i2c_read_reg(ts, ts->tdata->whoami_cmd, &chip_id);
 	if (error) {
 		dev_err(dev, "chip ID read failure: %d\n", error);
 		return error;
 	}
 
-	if (chip_id != IST3038C_WHOAMI) {
+	if (chip_id != ts->tdata->whoami_val) {
 		dev_err(dev, "unknown chip ID: 0x%x\n", chip_id);
 		return -EINVAL;
 	}
@@ -343,9 +363,25 @@ static int imagis_resume(struct device *dev)
 
 static DEFINE_SIMPLE_DEV_PM_OPS(imagis_pm_ops, imagis_suspend, imagis_resume);
 
+static const struct imagis_properties imagis_3038b_data = {
+	.interrupt_msg_cmd = IST3038B_REG_STATUS,
+	.touch_coord_cmd = IST3038B_REG_STATUS,
+	.whoami_cmd = IST3038B_REG_CHIPID,
+	.whoami_val = IST3038B_WHOAMI,
+	.protocol_b = true,
+};
+
+static const struct imagis_properties imagis_3038c_data = {
+	.interrupt_msg_cmd = IST3038C_REG_INTR_MESSAGE,
+	.touch_coord_cmd = IST3038C_REG_TOUCH_COORD,
+	.whoami_cmd = IST3038C_REG_CHIPID,
+	.whoami_val = IST3038C_WHOAMI,
+};
+
 #ifdef CONFIG_OF
 static const struct of_device_id imagis_of_match[] = {
-	{ .compatible = "imagis,ist3038c", },
+	{ .compatible = "imagis,ist3038b", .data = &imagis_3038b_data },
+	{ .compatible = "imagis,ist3038c", .data = &imagis_3038c_data },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, imagis_of_match);
-- 
2.43.0

[PATCH v4 4/5] dt-bindings: input/touchscreen: imagis: add compatible for IST3032C

[Karel Balej]

From: Karel Balej <balejk@matfyz.cz>

IST3032C is a touchscreen IC which seems mostly compatible with IST3038C
except that it reports a different chip ID value.

Signed-off-by: Karel Balej <balejk@matfyz.cz>
---

Notes:
    v4:
    * Reword commit description to mention how this IC differs from the
      already supported.

 .../devicetree/bindings/input/touchscreen/imagis,ist3038c.yaml   | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/input/touchscreen/imagis,ist3038c.yaml b/Documentation/devicetree/bindings/input/touchscreen/imagis,ist3038c.yaml
index b5372c4eae56..2af71cbcc97d 100644
--- a/Documentation/devicetree/bindings/input/touchscreen/imagis,ist3038c.yaml
+++ b/Documentation/devicetree/bindings/input/touchscreen/imagis,ist3038c.yaml
@@ -18,6 +18,7 @@ properties:
 
   compatible:
     enum:
+      - imagis,ist3032c
       - imagis,ist3038b
       - imagis,ist3038c
 
-- 
2.43.0

Re: [PATCH v4 4/5] dt-bindings: input/touchscreen: imagis: add compatible for IST3032C

[Rob Herring]

On Sat, 20 Jan 2024 20:11:15 +0100, Karel Balej wrote:
> From: Karel Balej <balejk@matfyz.cz>
> 
> IST3032C is a touchscreen IC which seems mostly compatible with IST3038C
> except that it reports a different chip ID value.
> 
> Signed-off-by: Karel Balej <balejk@matfyz.cz>
> ---
> 
> Notes:
>     v4:
>     * Reword commit description to mention how this IC differs from the
>       already supported.
> 
>  .../devicetree/bindings/input/touchscreen/imagis,ist3038c.yaml   | 1 +
>  1 file changed, 1 insertion(+)
> 

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

[PATCH v4 5/5] input/touchscreen: imagis: add support for IST3032C

[Karel Balej]

From: Karel Balej <balejk@matfyz.cz>

IST3032C is a touchscreen chip used for instance in the
samsung,coreprimevelte smartphone, with which this was tested. Add the
chip specific information to the driver.

Reviewed-by: Markuss Broks <markuss.broks@gmail.com>
Signed-off-by: Karel Balej <balejk@matfyz.cz>
---

Notes:
    v4:
    * Change the WHOAMI definition position to preserve alphanumerical order
      of the definitions.
    * Add Markuss' Reviewed-by trailer.

 drivers/input/touchscreen/imagis.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/input/touchscreen/imagis.c b/drivers/input/touchscreen/imagis.c
index 9af8a6332ae6..e1fafa561ee3 100644
--- a/drivers/input/touchscreen/imagis.c
+++ b/drivers/input/touchscreen/imagis.c
@@ -11,6 +11,8 @@
 #include <linux/property.h>
 #include <linux/regulator/consumer.h>
 
+#define IST3032C_WHOAMI			0x32c
+
 #define IST3038B_REG_STATUS		0x20
 #define IST3038B_REG_CHIPID		0x30
 #define IST3038B_WHOAMI			0x30380b
@@ -363,6 +365,13 @@ static int imagis_resume(struct device *dev)
 
 static DEFINE_SIMPLE_DEV_PM_OPS(imagis_pm_ops, imagis_suspend, imagis_resume);
 
+static const struct imagis_properties imagis_3032c_data = {
+	.interrupt_msg_cmd = IST3038C_REG_INTR_MESSAGE,
+	.touch_coord_cmd = IST3038C_REG_TOUCH_COORD,
+	.whoami_cmd = IST3038C_REG_CHIPID,
+	.whoami_val = IST3032C_WHOAMI,
+};
+
 static const struct imagis_properties imagis_3038b_data = {
 	.interrupt_msg_cmd = IST3038B_REG_STATUS,
 	.touch_coord_cmd = IST3038B_REG_STATUS,
@@ -380,6 +389,7 @@ static const struct imagis_properties imagis_3038c_data = {
 
 #ifdef CONFIG_OF
 static const struct of_device_id imagis_of_match[] = {
+	{ .compatible = "imagis,ist3032c", .data = &imagis_3032c_data },
 	{ .compatible = "imagis,ist3038b", .data = &imagis_3038b_data },
 	{ .compatible = "imagis,ist3038c", .data = &imagis_3038c_data },
 	{ },
-- 
2.43.0