[PATCH v4 0/3] Input: Add TouchNetix axiom touchscreen driver

[PATCH v4 0/3] Input: Add TouchNetix axiom touchscreen driver

[Kamel Bouhara]

Add a new driver for the TouchNetix's axiom family of
touchscreen controller. This driver only support i2c
and can be later adapted for SPI and USB support.

---
Changes in v2:
 - Add device tree binding documentation
 - Move core functions in axiom_i2c as we only care about i2c support now
 - Use static function when required
 - Use syntax dev_err_probe()
 - Add an hardware based reset

Changes in v3:
 - Remove irq-gpios property in dt-binding
 - Use a generic node name
 - Fix issues reported in https://lore.kernel.org/oe-kbuild-all/202310100300.oAC2M62R-lkp@intel.com/

Changes in v4:
 - Cleanup unused headers and macros
 - Use standard kernel type
 - Namespace structures and functions
 - Use packed struct when possible to avoid bitfield operators
 - Fix missing break when address is found in axiom_populate_target_address()
 - Split reads in two steps for the reports, first length then report
   itself so we only read required bytes
 - Get poll-interval from devicetree
 - Add VDDI/VDDA regulators
 - Add a startup delay of 110 ms required after VDDA/VDDI is applied
 - Remove axiom_i2c_write() as it is no more used

Kamel Bouhara (3):
  dt-bindings: vendor-prefixes: Add TouchNetix AS
  dt-bindings: input: Add TouchNetix axiom touchscreen
  Input: Add TouchNetix axiom i2c touchscreen driver

 .../input/touchscreen/touchnetix,ax54a.yaml   |  56 ++
 .../devicetree/bindings/vendor-prefixes.yaml  |   2 +
 MAINTAINERS                                   |   7 +
 drivers/input/touchscreen/Kconfig             |  12 +
 drivers/input/touchscreen/Makefile            |   1 +
 drivers/input/touchscreen/touchnetix_axiom.c  | 675 ++++++++++++++++++
 6 files changed, 753 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/touchscreen/touchnetix,ax54a.yaml
 create mode 100644 drivers/input/touchscreen/touchnetix_axiom.c

--
2.25.1

[PATCH v4 1/3] dt-bindings: vendor-prefixes: Add TouchNetix AS

[Kamel Bouhara]

Add vendor prefix for TouchNetix AS (https://www.touchnetix.com/products/).

Signed-off-by: Kamel Bouhara <kamel.bouhara@bootlin.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.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 573578db9509..78581001a79c 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
+++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
@@ -1400,6 +1400,8 @@ patternProperties:
     description: Toradex AG
   "^toshiba,.*":
     description: Toshiba Corporation
+  "^touchnetix,.*":
+    description: TouchNetix AS
   "^toumaz,.*":
     description: Toumaz
   "^tpk,.*":
-- 
2.25.1

[PATCH v4 2/3] dt-bindings: input: Add TouchNetix axiom touchscreen

[Kamel Bouhara]

Add the TouchNetix axiom I2C touchscreen device tree bindings
documentation.

Signed-off-by: Kamel Bouhara <kamel.bouhara@bootlin.com>
---
 .../input/touchscreen/touchnetix,ax54a.yaml   | 56 +++++++++++++++++++
 MAINTAINERS                                   |  6 ++
 2 files changed, 62 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/touchscreen/touchnetix,ax54a.yaml

diff --git a/Documentation/devicetree/bindings/input/touchscreen/touchnetix,ax54a.yaml b/Documentation/devicetree/bindings/input/touchscreen/touchnetix,ax54a.yaml
new file mode 100644
index 000000000000..ff216a2bacc5
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/touchnetix,ax54a.yaml
@@ -0,0 +1,56 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/touchscreen/touchnetix,ax54a.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: TouchNetix Axiom series touchscreen controller
+
+maintainers:
+  - Kamel Bouhara <kamel.bouhara@bootlin.com>
+
+properties:
+  compatible:
+    const: touchnetix,ax54a
+
+  reg:
+    const: 0x66
+
+  interrupts:
+    maxItems: 1
+
+  reset-gpios:
+    maxItems: 1
+
+  poll-interval:
+    description: Poll interval time in milliseconds.
+
+  VDDA-supply:
+    description: Analog power supply regulator on VDDA pin
+
+  VDDI-supply:
+    description: I/O power supply regulator on VDDI pin
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+      touchscreen@66 {
+        compatible = "touchnetix,ax54a";
+        reg = <0x66>;
+        interrupt-parent = <&gpio2>;
+        interrupts = <2 IRQ_TYPE_EDGE_FALLING>;
+        reset-gpios = <&gpio1 1 GPIO_ACTIVE_HIGH>;
+      };
+    };
+
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index 7608b714653f..4752d8436dbb 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -21431,6 +21431,12 @@ S:	Maintained
 F:	Documentation/ABI/testing/sysfs-class-firmware-attributes
 F:	drivers/platform/x86/think-lmi.?
 
+TOUCHNETIX AXIOM I2C TOUCHSCREEN DRIVER
+M:	Kamel Bouhara <kamel.bouhara@bootlin.com>
+L:	linux-input@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/input/touchscreen/touchnetix,ax54a.yaml
+
 THUNDERBOLT DMA TRAFFIC TEST DRIVER
 M:	Isaac Hazan <isaac.hazan@intel.com>
 L:	linux-usb@vger.kernel.org
-- 
2.25.1

Re: [PATCH v4 2/3] dt-bindings: input: Add TouchNetix axiom touchscreen

[Krzysztof Kozlowski]

On 04/12/2023 15:05, Kamel Bouhara wrote:
> Add the TouchNetix axiom I2C touchscreen device tree bindings
> documentation.
> 
> Signed-off-by: Kamel Bouhara <kamel.bouhara@bootlin.com>

> +$id: http://devicetree.org/schemas/input/touchscreen/touchnetix,ax54a.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: TouchNetix Axiom series touchscreen controller
> +
> +maintainers:
> +  - Kamel Bouhara <kamel.bouhara@bootlin.com>
> +

Why you do not have ref to touchscreen? Is it not a touchscreen?


> +properties:
> +  compatible:
> +    const: touchnetix,ax54a
> +
> +  reg:
> +    const: 0x66
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  reset-gpios:
> +    maxItems: 1
> +
> +  poll-interval:
> +    description: Poll interval time in milliseconds.

Missing type or missing ref to input. It seems you want to use existing
property thus no type, but you did not reference input.yaml

> +
> +  VDDA-supply:

lowercase

> +    description: Analog power supply regulator on VDDA pin
> +
> +  VDDI-supply:

lowercase

> +    description: I/O power supply regulator on VDDI pin
> +
> +required:
> +  - compatible
> +  - reg

Supplies are usually required. Devices rarely can operate without  power.

> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/gpio/gpio.h>
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +    i2c {
> +      #address-cells = <1>;
> +      #size-cells = <0>;

Blank line

> +      touchscreen@66 {
> +        compatible = "touchnetix,ax54a";
> +        reg = <0x66>;
> +        interrupt-parent = <&gpio2>;
> +        interrupts = <2 IRQ_TYPE_EDGE_FALLING>;
> +        reset-gpios = <&gpio1 1 GPIO_ACTIVE_HIGH>;
> +      };

Best regards,
Krzysztof

Re: [PATCH v4 2/3] dt-bindings: input: Add TouchNetix axiom touchscreen

[Kamel BOUHARA]

Le 2023-12-05 09:15, Krzysztof Kozlowski a écrit :
> On 04/12/2023 15:05, Kamel Bouhara wrote:
>> Add the TouchNetix axiom I2C touchscreen device tree bindings
>> documentation.
>> 
>> Signed-off-by: Kamel Bouhara <kamel.bouhara@bootlin.com>
> 
>> +$id: 
>> http://devicetree.org/schemas/input/touchscreen/touchnetix,ax54a.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: TouchNetix Axiom series touchscreen controller
>> +
>> +maintainers:
>> +  - Kamel Bouhara <kamel.bouhara@bootlin.com>
>> +
> 
> Why you do not have ref to touchscreen? Is it not a touchscreen?

The common properties are not used or applicable here, should I still 
ref touchscreen ?

> 
> 
>> +properties:
>> +  compatible:
>> +    const: touchnetix,ax54a
>> +
>> +  reg:
>> +    const: 0x66
>> +
>> +  interrupts:
>> +    maxItems: 1
>> +
>> +  reset-gpios:
>> +    maxItems: 1
>> +
>> +  poll-interval:
>> +    description: Poll interval time in milliseconds.
> 
> Missing type or missing ref to input. It seems you want to use existing
> property thus no type, but you did not reference input.yaml
> 

Ok is this the right way to do it :

allOf:
   - $ref: input.yaml#

properties:

   poll-interval: true

>> +
>> +  VDDA-supply:
> 
> lowercase
> 
>> +    description: Analog power supply regulator on VDDA pin
>> +
>> +  VDDI-supply:
> 
> lowercase
> 

Ack.

>> +    description: I/O power supply regulator on VDDI pin
>> +
>> +required:
>> +  - compatible
>> +  - reg
> 
> Supplies are usually required. Devices rarely can operate without  
> power.

Indeed, can I still have them optional in the driver ?

I have fixed regulators and Im testing on x86 hence I
would like to avoid having extra acpi code to supply them.

> 
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> +  - |
>> +    #include <dt-bindings/gpio/gpio.h>
>> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
>> +    i2c {
>> +      #address-cells = <1>;
>> +      #size-cells = <0>;
> 
> Blank line

Ack.

> 
>> +      touchscreen@66 {
>> +        compatible = "touchnetix,ax54a";
>> +        reg = <0x66>;
>> +        interrupt-parent = <&gpio2>;
>> +        interrupts = <2 IRQ_TYPE_EDGE_FALLING>;
>> +        reset-gpios = <&gpio1 1 GPIO_ACTIVE_HIGH>;
>> +      };
> 
> Best regards,
> Krzysztof

Thanks
--
Kamel Bouhara, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com

Re: [PATCH v4 2/3] dt-bindings: input: Add TouchNetix axiom touchscreen

[Krzysztof Kozlowski]

On 05/12/2023 10:17, Kamel BOUHARA wrote:
> Le 2023-12-05 09:15, Krzysztof Kozlowski a écrit :
>> On 04/12/2023 15:05, Kamel Bouhara wrote:
>>> Add the TouchNetix axiom I2C touchscreen device tree bindings
>>> documentation.
>>>
>>> Signed-off-by: Kamel Bouhara <kamel.bouhara@bootlin.com>
>>
>>> +$id: 
>>> http://devicetree.org/schemas/input/touchscreen/touchnetix,ax54a.yaml#
>>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>>> +
>>> +title: TouchNetix Axiom series touchscreen controller
>>> +
>>> +maintainers:
>>> +  - Kamel Bouhara <kamel.bouhara@bootlin.com>
>>> +
>>
>> Why you do not have ref to touchscreen? Is it not a touchscreen?
> 
> The common properties are not used or applicable here, should I still 
> ref touchscreen ?

Why they are not applicable? Do you get the panel coordinates and sizes
from device registers or are they fixed somehow in the controller?


...

> 
>>> +    description: I/O power supply regulator on VDDI pin
>>> +
>>> +required:
>>> +  - compatible
>>> +  - reg
>>
>> Supplies are usually required. Devices rarely can operate without  
>> power.
> 
> Indeed, can I still have them optional in the driver ?

Yes, I comment here only about the bindings. Bindings are not related to
your driver, but to hardware.


Best regards,
Krzysztof

[PATCH v4 3/3] Input: Add TouchNetix axiom i2c touchscreen driver

[Kamel Bouhara]

Add a new driver for the TouchNetix's axiom family of
touchscreen controllers. This driver only supports i2c
and can be later adapted for SPI and USB support.

Signed-off-by: Kamel Bouhara <kamel.bouhara@bootlin.com>
---
 MAINTAINERS                                  |   1 +
 drivers/input/touchscreen/Kconfig            |  12 +
 drivers/input/touchscreen/Makefile           |   1 +
 drivers/input/touchscreen/touchnetix_axiom.c | 675 +++++++++++++++++++
 4 files changed, 689 insertions(+)
 create mode 100644 drivers/input/touchscreen/touchnetix_axiom.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 4752d8436dbb..337ddac6c74b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -21436,6 +21436,7 @@ M:	Kamel Bouhara <kamel.bouhara@bootlin.com>
 L:	linux-input@vger.kernel.org
 S:	Maintained
 F:	Documentation/devicetree/bindings/input/touchscreen/touchnetix,ax54a.yaml
+F:	drivers/input/touchscreen/touchnetix_axiom.c
 
 THUNDERBOLT DMA TRAFFIC TEST DRIVER
 M:	Isaac Hazan <isaac.hazan@intel.com>
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index e3e2324547b9..f36bee8d8696 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -803,6 +803,18 @@ config TOUCHSCREEN_MIGOR
 	  To compile this driver as a module, choose M here: the
 	  module will be called migor_ts.
 
+config TOUCHSCREEN_TOUCHNETIX_AXIOM
+	tristate "TouchNetix AXIOM based touchscreen controllers"
+	depends on I2C
+	help
+	  Say Y here if you have a axiom touchscreen connected to
+	  your system.
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called axiom.
+
 config TOUCHSCREEN_TOUCHRIGHT
 	tristate "Touchright serial touchscreen"
 	select SERIO
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 62bd24f3ac8e..8e32a2df5e18 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -88,6 +88,7 @@ obj-$(CONFIG_TOUCHSCREEN_SUR40)		+= sur40.o
 obj-$(CONFIG_TOUCHSCREEN_SURFACE3_SPI)	+= surface3_spi.o
 obj-$(CONFIG_TOUCHSCREEN_TI_AM335X_TSC)	+= ti_am335x_tsc.o
 obj-$(CONFIG_TOUCHSCREEN_TOUCHIT213)	+= touchit213.o
+obj-$(CONFIG_TOUCHSCREEN_TOUCHNETIX_AXIOM)	+= touchnetix_axiom.o
 obj-$(CONFIG_TOUCHSCREEN_TOUCHRIGHT)	+= touchright.o
 obj-$(CONFIG_TOUCHSCREEN_TOUCHWIN)	+= touchwin.o
 obj-$(CONFIG_TOUCHSCREEN_TS4800)	+= ts4800-ts.o
diff --git a/drivers/input/touchscreen/touchnetix_axiom.c b/drivers/input/touchscreen/touchnetix_axiom.c
new file mode 100644
index 000000000000..9783e89f9e3a
--- /dev/null
+++ b/drivers/input/touchscreen/touchnetix_axiom.c
@@ -0,0 +1,675 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * TouchNetix axiom Touchscreen Driver
+ *
+ * Copyright (C) 2020-2023 TouchNetix Ltd.
+ *
+ * Author(s): Bart Prescott <bartp@baasheep.co.uk>
+ *            Pedro Torruella <pedro.torruella@touchnetix.com>
+ *            Mark Satterthwaite <mark.satterthwaite@touchnetix.com>
+ *            Hannah Rossiter <hannah.rossiter@touchnetix.com>
+ *            Kamel Bouhara <kamel.bouhara@bootlin.com>
+ *
+ */
+#include <linux/bitfield.h>
+#include <linux/crc16.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+
+#define AXIOM_PROX_LEVEL		-128
+/*
+ * Register group u31 has 2 pages for usage table entries.
+ */
+#define AXIOM_U31_MAX_USAGES		((2 * AXIOM_COMMS_PAGE_SIZE) / AXIOM_U31_BYTES_PER_USAGE)
+#define AXIOM_U31_BYTES_PER_USAGE	6
+#define AXIOM_U31_PAGE0_LENGTH		0x0C
+#define AXIOM_U31_BOOTMODE_MASK		BIT(7)
+#define AXIOM_U31_DEVID_MASK		GENMASK(14, 0)
+
+#define AXIOM_CMD_HEADER_READ_MASK	BIT(15)
+#define AXIOM_U41_MAX_TARGETS		10
+
+#define AXIOM_U46_AUX_CHANNELS		4
+#define AXIOM_U46_AUX_MASK		GENMASK(11, 0)
+
+#define AXIOM_COMMS_MAX_USAGE_PAGES	3
+#define AXIOM_COMMS_PAGE_SIZE		256
+#define AXIOM_COMMS_REPORT_LEN_MASK	GENMASK(6, 0)
+
+#define AXIOM_REPORT_USAGE_ID		0x34
+#define AXIOM_DEVINFO_USAGE_ID		0x31
+#define AXIOM_USAGE_2HB_REPORT_ID	0x01
+#define AXIOM_USAGE_2AUX_REPORT_ID	0x46
+#define AXIOM_USAGE_2DCTS_REPORT_ID	0x41
+
+#define AXIOM_PAGE_OFFSET_MASK		GENMASK(6, 0)
+
+struct axiom_devinfo {
+	u16 device_id;
+	u8 fw_minor;
+	u8 fw_major;
+	u8 fw_info_extra;
+	u8 tcp_revision;
+	u8 bootloader_fw_minor;
+	u8 bootloader_fw_major;
+	u16 jedec_id;
+	u8 num_usages;
+} __packed;
+
+/*
+ * Describes parameters of a specific usage, essentially a single element of
+ * the "Usage Table"
+ */
+struct axiom_usage_entry {
+	u8 id;
+	u8 is_report;
+	u8 start_page;
+	u8 num_pages;
+};
+
+/*
+ * Represents state of a touch or target when detected prior a touch (eg.
+ * hover or proximity events).
+ */
+enum axiom_target_state {
+	AXIOM_TARGET_STATE_NOT_PRESENT = 0,
+	AXIOM_TARGET_STATE_PROX = 1,
+	AXIOM_TARGET_STATE_HOVER = 2,
+	AXIOM_TARGET_STATE_TOUCHING = 3,
+};
+
+struct axiom_u41_target {
+	enum axiom_target_state state;
+	u16 x;
+	u16 y;
+	s8 z;
+	bool insert;
+	bool touch;
+};
+
+struct axiom_target_report {
+	u8 index;
+	u8 present;
+	u16 x;
+	u16 y;
+	s8 z;
+};
+
+struct axiom_cmd_header {
+	__le16 target_address;
+	__le16 length;
+} __packed;
+
+struct axiom_data {
+	struct axiom_devinfo devinfo;
+	struct device *dev;
+	struct gpio_desc *reset_gpio;
+	struct i2c_client *client;
+	struct input_dev *input_dev;
+	u32 max_report_len;
+	char rx_buf[AXIOM_COMMS_MAX_USAGE_PAGES * AXIOM_COMMS_PAGE_SIZE];
+	struct axiom_u41_target targets[AXIOM_U41_MAX_TARGETS];
+	struct axiom_usage_entry usage_table[AXIOM_U31_MAX_USAGES];
+	bool usage_table_populated;
+	struct regulator *vdda;
+	struct regulator *vddi;
+};
+
+/*
+ * axiom devices are typically configured to report
+ * touches at a rate of 100Hz (10ms). For systems
+ * that require polling for reports.
+ * When reports are polled, it will be expected to
+ * occasionally observe the overflow bit being set
+ * in the reports. This indicates that reports are not
+ * being read fast enough.
+ */
+#define POLL_INTERVAL_DEFAULT_MS 10
+
+/* Translate usage/page/offset triplet into physical address. */
+static u16 axiom_usage_to_target_address(struct axiom_data *ts, char usage, char page,
+					 char offset)
+{
+	struct axiom_usage_entry *usage_table;
+	struct axiom_devinfo *device_info;
+	u32 i;
+
+	device_info = &ts->devinfo;
+	usage_table = ts->usage_table;
+
+	/* At the moment the convention is that u31 is always at physical address 0x0 */
+	if (!ts->usage_table_populated) {
+		if (usage == AXIOM_DEVINFO_USAGE_ID)
+			return ((page << 8) + offset);
+		else
+			return 0xffff;
+	}
+
+	for (i = 0; i < ts->devinfo.num_usages; i++) {
+		if (usage_table[i].id != usage)
+			continue;
+
+		if (page >= usage_table[i].num_pages) {
+			dev_err(ts->dev, "Invalid usage table! usage: %u, page: %u, offset: %u\n",
+				usage, page, offset);
+			return 0xffff;
+		}
+		break;
+	}
+
+	return ((usage_table[i].start_page + page) << 8) + offset;
+}
+
+static int axiom_i2c_read(struct i2c_client *client, u8 usage, u8 page, u8 *buf, u16 len)
+{
+	struct axiom_data *ts = i2c_get_clientdata(client);
+	struct axiom_cmd_header cmd_header;
+	u8 buffer[sizeof(cmd_header) + AXIOM_COMMS_PAGE_SIZE];
+	struct i2c_msg msg;
+	int error;
+
+	cmd_header.target_address = cpu_to_le16(axiom_usage_to_target_address(ts, usage, page, 0));
+	cmd_header.length = cpu_to_le16(len | AXIOM_CMD_HEADER_READ_MASK);
+
+	memcpy(&buffer[0], &cmd_header, sizeof(cmd_header));
+	memcpy(&buffer[sizeof(cmd_header)], buf, len);
+
+	msg.addr = client->addr;
+	msg.flags = 0;
+	msg.len = len + sizeof(cmd_header);
+	msg.buf = (u8 *)buffer;
+
+	error = i2c_transfer(client->adapter, &msg, 1);
+	if (error != 1) {
+		dev_err(&client->dev,
+			"Failed reading usage %#x page %#x, error=%d\n",
+			usage, page, error);
+		return error;
+	}
+
+	usleep_range(100, 250);
+
+	return 0;
+}
+
+/*
+ * One of the main purposes for reading the usage table is to identify
+ * which usages reside at which TA address.
+ * When performing subsequent reads or writes to AXIOM, the TA is used
+ * to specify which usage is being accessed.
+ * Consider the following discovery code which will build up the usage table.
+ */
+static u32 axiom_populate_usage_table(struct axiom_data *ts)
+{
+	struct axiom_usage_entry *usage_table;
+	u32 max_report_len = 0;
+	char *rx_data = ts->rx_buf;
+	u32 usage_id;
+	int error;
+
+	usage_table = ts->usage_table;
+
+	/* Read the second page of usage u31 to get the usage table */
+	error = axiom_i2c_read(ts->client, AXIOM_DEVINFO_USAGE_ID, 1, rx_data,
+			       (AXIOM_U31_BYTES_PER_USAGE * ts->devinfo.num_usages));
+	if (error)
+		return error;
+
+	for (usage_id = 0; usage_id < ts->devinfo.num_usages; usage_id++) {
+		u16 offset = (usage_id * AXIOM_U31_BYTES_PER_USAGE);
+		u8 id = rx_data[offset + 0];
+		u8 start_page = rx_data[offset + 1];
+		u8 num_pages = rx_data[offset + 2];
+		u32 max_offset = ((rx_data[offset + 3] & AXIOM_PAGE_OFFSET_MASK) + 1) * 2;
+
+		if (!num_pages)
+			usage_table[usage_id].is_report = true;
+
+		/* Store the entry into the usage table */
+		usage_table[usage_id].id = id;
+		usage_table[usage_id].start_page = start_page;
+		usage_table[usage_id].num_pages = num_pages;
+
+		dev_dbg(ts->dev, "Usage u%02x Info: %*ph\n", id,
+			AXIOM_U31_BYTES_PER_USAGE, &rx_data[offset]);
+
+		/* Identify the max report length the module will receive */
+		if (usage_table[usage_id].is_report && max_offset > max_report_len)
+			max_report_len = max_offset;
+	}
+
+	ts->usage_table_populated = true;
+
+	return max_report_len;
+}
+
+static int axiom_discover(struct axiom_data *ts)
+{
+	int error;
+
+	/*
+	 * Fetch the first page of usage u31 to get the
+	 * device information and the number of usages
+	 */
+	error = axiom_i2c_read(ts->client, AXIOM_DEVINFO_USAGE_ID, 0, (char *)&ts->devinfo,
+			       AXIOM_U31_PAGE0_LENGTH);
+	if (error)
+		return error;
+
+	dev_dbg(ts->dev, "  Boot Mode      : %s\n",
+		FIELD_GET(AXIOM_U31_BOOTMODE_MASK, ts->devinfo.device_id) ? "BLP" : "TCP");
+	dev_dbg(ts->dev, "  Device ID      : %04lx\n",
+		FIELD_GET(AXIOM_U31_DEVID_MASK,	ts->devinfo.device_id));
+	dev_dbg(ts->dev, "  Firmware Rev   : %02x.%02x\n", ts->devinfo.fw_major,
+		ts->devinfo.fw_minor);
+	dev_dbg(ts->dev, "  Bootloader Rev : %02x.%02x\n", ts->devinfo.bootloader_fw_major,
+		ts->devinfo.bootloader_fw_minor);
+	dev_dbg(ts->dev, "  FW Extra Info  : %04x\n", ts->devinfo.fw_info_extra);
+	dev_dbg(ts->dev, "  Silicon        : %04x\n", ts->devinfo.jedec_id);
+	dev_dbg(ts->dev, "  Number usages        : %04x\n", ts->devinfo.num_usages);
+
+	ts->max_report_len = axiom_populate_usage_table(ts);
+	if (!ts->max_report_len || !ts->devinfo.num_usages)
+		return -EINVAL;
+
+	dev_dbg(ts->dev, "Max Report Length: %u\n", ts->max_report_len);
+
+	return 0;
+}
+
+/*
+ * Support function to axiom_process_u41_report.
+ * Generates input-subsystem events for every target.
+ * After calling this function the caller shall issue
+ * a Sync to the input sub-system.
+ */
+static bool axiom_process_u41_report_target(struct axiom_data *ts,
+					    struct axiom_target_report *target)
+{
+	struct input_dev *input_dev = ts->input_dev;
+	struct axiom_u41_target *target_prev_state;
+	enum axiom_target_state current_state;
+	bool update = false;
+	int slot;
+
+	/* Verify the target index */
+	if (target->index >= AXIOM_U41_MAX_TARGETS) {
+		dev_dbg(ts->dev, "Invalid target index! %u\n", target->index);
+		return false;
+	}
+
+	target_prev_state = &ts->targets[target->index];
+
+	current_state = AXIOM_TARGET_STATE_NOT_PRESENT;
+
+	if (target->present) {
+		if (target->z >= 0)
+			current_state = AXIOM_TARGET_STATE_TOUCHING;
+		else if (target->z > AXIOM_PROX_LEVEL && target->z < 0)
+			current_state = AXIOM_TARGET_STATE_HOVER;
+		else if (target->z == AXIOM_PROX_LEVEL)
+			current_state = AXIOM_TARGET_STATE_PROX;
+	}
+
+	if (target_prev_state->state == current_state &&
+	    target_prev_state->x == target->x &&
+	    target_prev_state->y == target->y &&
+	    target_prev_state->z == target->z) {
+		return false;
+	}
+
+	slot = target->index;
+
+	dev_dbg(ts->dev, "U41 Target T%u, slot:%u present:%u, x:%u, y:%u, z:%d\n",
+		target->index, slot, target->present,
+		target->x, target->y, target->z);
+
+	switch (current_state) {
+	case AXIOM_TARGET_STATE_NOT_PRESENT:
+	case AXIOM_TARGET_STATE_PROX:
+		if (!target_prev_state->insert)
+			break;
+		update = true;
+		target_prev_state->insert = false;
+		input_mt_slot(input_dev, slot);
+
+		if (!slot)
+			input_report_key(input_dev, BTN_TOUCH, 0);
+
+		input_mt_report_slot_inactive(input_dev);
+		/*
+		 * make sure the previous coordinates are
+		 * all off screen when the finger comes back
+		 */
+		target->x = 65535;
+		target->y = 65535;
+		target->z = AXIOM_PROX_LEVEL;
+		break;
+	case AXIOM_TARGET_STATE_HOVER:
+	case AXIOM_TARGET_STATE_TOUCHING:
+		target_prev_state->insert = true;
+		update = true;
+		input_mt_slot(input_dev, slot);
+		input_report_abs(input_dev, ABS_MT_TRACKING_ID, slot);
+		input_report_abs(input_dev, ABS_MT_POSITION_X, target->x);
+		input_report_abs(input_dev, ABS_X, target->x);
+		input_report_abs(input_dev, ABS_MT_POSITION_Y, target->y);
+		input_report_abs(input_dev, ABS_Y, target->y);
+
+		if (current_state == AXIOM_TARGET_STATE_TOUCHING) {
+			input_report_abs(input_dev, ABS_MT_DISTANCE, 0);
+			input_report_abs(input_dev, ABS_DISTANCE, 0);
+			input_report_abs(input_dev, ABS_MT_PRESSURE, target->z);
+			input_report_abs(input_dev, ABS_PRESSURE, target->z);
+		} else {
+			input_report_abs(input_dev, ABS_MT_DISTANCE, -target->z);
+			input_report_abs(input_dev, ABS_DISTANCE, -target->z);
+			input_report_abs(input_dev, ABS_MT_PRESSURE, 0);
+			input_report_abs(input_dev, ABS_PRESSURE, 0);
+		}
+
+		if (!slot)
+			input_report_key(input_dev, BTN_TOUCH, (current_state ==
+					 AXIOM_TARGET_STATE_TOUCHING));
+		break;
+	default:
+		break;
+	}
+
+	target_prev_state->state = current_state;
+	target_prev_state->x = target->x;
+	target_prev_state->y = target->y;
+	target_prev_state->z = target->z;
+
+	return update;
+}
+
+/*
+ * U41 is the output report of the 2D CTS and contains the status of targets
+ * (including contacts and pre-contacts) along with their X,Y,Z values.
+ * When a target has been removed (no longer detected),
+ * the corresponding X,Y,Z values will be zeroed.
+ */
+static bool axiom_process_u41_report(struct axiom_data *ts, char *rx_buf)
+{
+	struct axiom_target_report target;
+	bool update_done = false;
+	u16 target_status;
+	u32 i;
+
+	target_status = ((rx_buf[1]) | (rx_buf[2] << 8));
+
+	for (i = 0; i < AXIOM_U41_MAX_TARGETS; i++) {
+		char target_step = i * 4;
+
+		target.index = i;
+		target.present = ((target_status & (1 << i)) != 0) ? 1 : 0;
+		target.x = (rx_buf[(target_step + 3)] | (rx_buf[target_step + 4] << 8));
+		target.y = (rx_buf[(target_step + 5)] | (rx_buf[target_step + 6] << 8));
+		target.z = (s8)(rx_buf[i + 43]);
+		update_done |= axiom_process_u41_report_target(ts, &target);
+	}
+
+	return update_done;
+}
+
+/*
+ * U46 report contains a low level measurement data generated by the CDS
+ * algorithms from the AUX channels. This information is useful when tuning
+ * multi-press to assess mechanical consistency in the unit's construction.
+ */
+static void axiom_process_u46_report(struct axiom_data *ts, char *rx_buf)
+{
+	struct input_dev *input_dev = ts->input_dev;
+	u32 event_value;
+	u16 aux_value;
+	u32 i = 0;
+
+	for (i = 0; i < AXIOM_U46_AUX_CHANNELS; i++) {
+		char target_step = i * 2;
+
+		aux_value = ((rx_buf[target_step + 2] << 8) | (rx_buf[target_step + 1]))
+			     & AXIOM_U46_AUX_MASK;
+		event_value = (i << 16) | (aux_value);
+		input_event(input_dev, EV_MSC, MSC_RAW, event_value);
+	}
+}
+
+/*
+ * Validates the crc and demultiplexes the axiom reports to the appropriate
+ * report handler
+ */
+static int axiom_handle_events(struct axiom_data *ts)
+{
+	struct input_dev *input_dev = ts->input_dev;
+	char *report_data = ts->rx_buf;
+	char report_len;
+	struct device *dev = ts->dev;
+	u16 crc_report;
+	u16 crc_calc;
+	int error;
+
+	error = axiom_i2c_read(ts->client, AXIOM_REPORT_USAGE_ID, 0, &report_len,
+			       sizeof(report_len));
+	if (error)
+		return error;
+
+	report_len = (report_len & AXIOM_COMMS_REPORT_LEN_MASK) << 1;
+	if (!report_len) {
+		dev_err(dev, "Zero length report discarded\n");
+		return -ENODATA;
+	}
+
+	error = axiom_i2c_read(ts->client, AXIOM_REPORT_USAGE_ID, 0, report_data, report_len);
+	if (error)
+		return error;
+
+	/* Validate the report CRC */
+	crc_report = (report_data[report_len - 1] << 8) | (report_data[report_len - 2]);
+	/* Length is in 16 bit words and remove the size of the CRC16 itself */
+	crc_calc = crc16(0, report_data, (report_len - 2));
+
+	if (crc_calc != crc_report) {
+		dev_err(dev,
+			"CRC mismatch! Expected: %#x, Calculated CRC: %#x.\n",
+			crc_report, crc_calc);
+		return -EINVAL;
+	}
+
+	switch (report_data[1]) {
+	case AXIOM_USAGE_2DCTS_REPORT_ID:
+		if (axiom_process_u41_report(ts, &report_data[1])) {
+			input_mt_sync_frame(input_dev);
+			input_sync(input_dev);
+		}
+		break;
+
+	case AXIOM_USAGE_2AUX_REPORT_ID:
+		/* This is an aux report (force) */
+		axiom_process_u46_report(ts, &report_data[1]);
+		input_mt_sync(input_dev);
+		input_sync(input_dev);
+		break;
+
+	case AXIOM_USAGE_2HB_REPORT_ID:
+		/* This is a heartbeat report */
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void axiom_i2c_poll(struct input_dev *input_dev)
+{
+	struct axiom_data *ts = input_get_drvdata(input_dev);
+
+	axiom_handle_events(ts);
+}
+
+static irqreturn_t axiom_irq(int irq, void *dev_id)
+{
+	struct axiom_data *ts = dev_id;
+
+	axiom_handle_events(ts);
+
+	return IRQ_HANDLED;
+}
+
+static void axiom_reset(struct gpio_desc *reset_gpio)
+{
+	gpiod_set_value_cansleep(reset_gpio, 1);
+	usleep_range(1000, 2000);
+	gpiod_set_value_cansleep(reset_gpio, 0);
+	msleep(110);
+}
+
+static int axiom_i2c_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct input_dev *input_dev;
+	struct axiom_data *ts;
+	u32 startup_delay_ms;
+	u32 poll_interval;
+	int target;
+	int error;
+
+	ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
+	if (!ts)
+		return -ENOMEM;
+
+	ts->client = client;
+	i2c_set_clientdata(client, ts);
+	ts->dev = dev;
+
+	ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(ts->reset_gpio))
+		return dev_err_probe(dev, PTR_ERR(ts->reset_gpio), "failed to get reset GPIO\n");
+
+	if (ts->reset_gpio)
+		axiom_reset(ts->reset_gpio);
+
+	ts->vddi = devm_regulator_get_optional(dev, "VDDI");
+	if (!IS_ERR(ts->vddi)) {
+		error = regulator_enable(ts->vddi);
+		if (error)
+			return dev_err_probe(&client->dev, PTR_ERR(ts->vddi),
+					     "Failed to enable VDDI regulator\n");
+	}
+
+	ts->vdda = devm_regulator_get_optional(dev, "VDDA");
+	if (!IS_ERR(ts->vdda)) {
+		error = regulator_enable(ts->vdda);
+		if (error) {
+			dev_err(dev, "Failed to get VDDA regulator\n");
+			regulator_disable(ts->vddi);
+			return error;
+		}
+		if (!device_property_read_u32(dev, "startup-time-ms", &startup_delay_ms))
+			msleep(startup_delay_ms);
+	}
+
+	error = axiom_discover(ts);
+	if (error)
+		return dev_err_probe(dev, error, "Failed touchscreen discover\n");
+
+	input_dev = devm_input_allocate_device(ts->dev);
+	if (!input_dev)
+		return -ENOMEM;
+
+	input_dev->name = "TouchNetix axiom Touchscreen";
+	input_dev->phys = "input/axiom_ts";
+
+	/* Single Touch */
+	input_set_abs_params(input_dev, ABS_X, 0, 65535, 0, 0);
+	input_set_abs_params(input_dev, ABS_Y, 0, 65535, 0, 0);
+
+	/* Multi Touch */
+	/* Min, Max, Fuzz (expected noise in px, try 4?) and Flat */
+	input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0, 65535, 0, 0);
+	/* Min, Max, Fuzz (expected noise in px, try 4?) and Flat */
+	input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0, 65535, 0, 0);
+	input_set_abs_params(input_dev, ABS_MT_TOOL_TYPE, 0, MT_TOOL_MAX, 0, 0);
+	input_set_abs_params(input_dev, ABS_MT_DISTANCE, 0, 127, 0, 0);
+	input_set_abs_params(input_dev, ABS_MT_PRESSURE, 0, 127, 0, 0);
+
+	input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
+
+	/* Registers the axiom device as a touchscreen instead of a mouse pointer */
+	error = input_mt_init_slots(input_dev, AXIOM_U41_MAX_TARGETS, INPUT_MT_DIRECT);
+	if (error)
+		return error;
+
+	/* Enables the raw data for up to 4 force channels to be sent to the input subsystem */
+	set_bit(EV_REL, input_dev->evbit);
+	set_bit(EV_MSC, input_dev->evbit);
+	/* Declare that we support "RAW" Miscellaneous events */
+	set_bit(MSC_RAW, input_dev->mscbit);
+
+	ts->input_dev = input_dev;
+	input_set_drvdata(ts->input_dev, ts);
+
+	/* Ensure that all reports are initialised to not be present. */
+	for (target = 0; target < AXIOM_U41_MAX_TARGETS; target++)
+		ts->targets[target].state = AXIOM_TARGET_STATE_NOT_PRESENT;
+
+	error = input_register_device(input_dev);
+	if (error)
+		return dev_err_probe(ts->dev, error,
+				     "Could not register with Input Sub-system.\n");
+
+	error = devm_request_threaded_irq(dev, client->irq, NULL,
+					  axiom_irq, IRQF_ONESHOT, dev_name(dev), ts);
+	if (error < 0) {
+		dev_warn(dev, "Request irq failed, falling back to polling mode");
+
+		error = input_setup_polling(input_dev, axiom_i2c_poll);
+		if (error)
+			return dev_err_probe(ts->dev, error, "Unable to set up polling mode\n");
+
+		if (!device_property_read_u32(ts->dev, "poll-interval", &poll_interval))
+			input_set_poll_interval(input_dev, poll_interval);
+		else
+			input_set_poll_interval(input_dev, POLL_INTERVAL_DEFAULT_MS);
+	}
+
+	return 0;
+}
+
+static const struct i2c_device_id axiom_i2c_id_table[] = {
+	{ "ax54a" },
+	{},
+};
+MODULE_DEVICE_TABLE(i2c, axiom_i2c_id_table);
+
+static const struct of_device_id axiom_i2c_of_match[] = {
+	{ .compatible = "touchnetix,ax54a", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, axiom_i2c_of_match);
+
+static struct i2c_driver axiom_i2c_driver = {
+	.driver = {
+		   .name = "axiom",
+		   .of_match_table = axiom_i2c_of_match,
+	},
+	.id_table = axiom_i2c_id_table,
+	.probe = axiom_i2c_probe,
+};
+module_i2c_driver(axiom_i2c_driver);
+MODULE_AUTHOR("Bart Prescott <bartp@baasheep.co.uk>");
+MODULE_AUTHOR("Pedro Torruella <pedro.torruella@touchnetix.com>");
+MODULE_AUTHOR("Mark Satterthwaite <mark.satterthwaite@touchnetix.com>");
+MODULE_AUTHOR("Hannah Rossiter <hannah.rossiter@touchnetix.com>");
+MODULE_AUTHOR("Kamel Bouhara <kamel.bouhara@bootlin.com>");
+MODULE_DESCRIPTION("TouchNetix axiom touchscreen I2C bus driver");
+MODULE_LICENSE("GPL");
-- 
2.25.1

Re: [PATCH v4 3/3] Input: Add TouchNetix axiom i2c touchscreen driver

[POPESCU Catalin]

On 04.12.23 15:05, Kamel Bouhara wrote:
> This email is not from Hexagon’s Office 365 instance. Please be careful while clicking links, opening attachments, or replying to this email.
>
>
> Add a new driver for the TouchNetix's axiom family of
> touchscreen controllers. This driver only supports i2c
> and can be later adapted for SPI and USB support.
>
> Signed-off-by: Kamel Bouhara <kamel.bouhara@bootlin.com>
> ---
>   MAINTAINERS                                  |   1 +
>   drivers/input/touchscreen/Kconfig            |  12 +
>   drivers/input/touchscreen/Makefile           |   1 +
>   drivers/input/touchscreen/touchnetix_axiom.c | 675 +++++++++++++++++++
>   4 files changed, 689 insertions(+)
>   create mode 100644 drivers/input/touchscreen/touchnetix_axiom.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 4752d8436dbb..337ddac6c74b 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -21436,6 +21436,7 @@ M:      Kamel Bouhara <kamel.bouhara@bootlin.com>
>   L:     linux-input@vger.kernel.org
>   S:     Maintained
>   F:     Documentation/devicetree/bindings/input/touchscreen/touchnetix,ax54a.yaml
> +F:     drivers/input/touchscreen/touchnetix_axiom.c
>
>   THUNDERBOLT DMA TRAFFIC TEST DRIVER
>   M:     Isaac Hazan <isaac.hazan@intel.com>
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index e3e2324547b9..f36bee8d8696 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -803,6 +803,18 @@ config TOUCHSCREEN_MIGOR
>            To compile this driver as a module, choose M here: the
>            module will be called migor_ts.
>
> +config TOUCHSCREEN_TOUCHNETIX_AXIOM
> +       tristate "TouchNetix AXIOM based touchscreen controllers"
> +       depends on I2C
> +       help
> +         Say Y here if you have a axiom touchscreen connected to
> +         your system.
> +
> +         If unsure, say N.
> +
> +         To compile this driver as a module, choose M here: the
> +         module will be called axiom.
> +
>   config TOUCHSCREEN_TOUCHRIGHT
>          tristate "Touchright serial touchscreen"
>          select SERIO
> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
> index 62bd24f3ac8e..8e32a2df5e18 100644
> --- a/drivers/input/touchscreen/Makefile
> +++ b/drivers/input/touchscreen/Makefile
> @@ -88,6 +88,7 @@ obj-$(CONFIG_TOUCHSCREEN_SUR40)               += sur40.o
>   obj-$(CONFIG_TOUCHSCREEN_SURFACE3_SPI) += surface3_spi.o
>   obj-$(CONFIG_TOUCHSCREEN_TI_AM335X_TSC)        += ti_am335x_tsc.o
>   obj-$(CONFIG_TOUCHSCREEN_TOUCHIT213)   += touchit213.o
> +obj-$(CONFIG_TOUCHSCREEN_TOUCHNETIX_AXIOM)     += touchnetix_axiom.o
>   obj-$(CONFIG_TOUCHSCREEN_TOUCHRIGHT)   += touchright.o
>   obj-$(CONFIG_TOUCHSCREEN_TOUCHWIN)     += touchwin.o
>   obj-$(CONFIG_TOUCHSCREEN_TS4800)       += ts4800-ts.o
> diff --git a/drivers/input/touchscreen/touchnetix_axiom.c b/drivers/input/touchscreen/touchnetix_axiom.c
> new file mode 100644
> index 000000000000..9783e89f9e3a
> --- /dev/null
> +++ b/drivers/input/touchscreen/touchnetix_axiom.c
> @@ -0,0 +1,675 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * TouchNetix axiom Touchscreen Driver
> + *
> + * Copyright (C) 2020-2023 TouchNetix Ltd.
> + *
> + * Author(s): Bart Prescott <bartp@baasheep.co.uk>
> + *            Pedro Torruella <pedro.torruella@touchnetix.com>
> + *            Mark Satterthwaite <mark.satterthwaite@touchnetix.com>
> + *            Hannah Rossiter <hannah.rossiter@touchnetix.com>
> + *            Kamel Bouhara <kamel.bouhara@bootlin.com>
> + *
> + */
> +#include <linux/bitfield.h>
> +#include <linux/crc16.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/input.h>
> +#include <linux/input/mt.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +
> +#define AXIOM_PROX_LEVEL               -128
> +/*
> + * Register group u31 has 2 pages for usage table entries.
> + */
> +#define AXIOM_U31_MAX_USAGES           ((2 * AXIOM_COMMS_PAGE_SIZE) / AXIOM_U31_BYTES_PER_USAGE)
> +#define AXIOM_U31_BYTES_PER_USAGE      6
> +#define AXIOM_U31_PAGE0_LENGTH         0x0C
> +#define AXIOM_U31_BOOTMODE_MASK                BIT(7)
> +#define AXIOM_U31_DEVID_MASK           GENMASK(14, 0)
> +
> +#define AXIOM_CMD_HEADER_READ_MASK     BIT(15)
> +#define AXIOM_U41_MAX_TARGETS          10
> +
> +#define AXIOM_U46_AUX_CHANNELS         4
> +#define AXIOM_U46_AUX_MASK             GENMASK(11, 0)
> +
> +#define AXIOM_COMMS_MAX_USAGE_PAGES    3
> +#define AXIOM_COMMS_PAGE_SIZE          256
> +#define AXIOM_COMMS_REPORT_LEN_MASK    GENMASK(6, 0)
> +
> +#define AXIOM_REPORT_USAGE_ID          0x34
> +#define AXIOM_DEVINFO_USAGE_ID         0x31
> +#define AXIOM_USAGE_2HB_REPORT_ID      0x01
> +#define AXIOM_USAGE_2AUX_REPORT_ID     0x46
> +#define AXIOM_USAGE_2DCTS_REPORT_ID    0x41
> +
> +#define AXIOM_PAGE_OFFSET_MASK         GENMASK(6, 0)
> +
> +struct axiom_devinfo {
> +       u16 device_id;
> +       u8 fw_minor;
> +       u8 fw_major;
> +       u8 fw_info_extra;
> +       u8 tcp_revision;
> +       u8 bootloader_fw_minor;
> +       u8 bootloader_fw_major;
> +       u16 jedec_id;
> +       u8 num_usages;
> +} __packed;
> +
> +/*
> + * Describes parameters of a specific usage, essentially a single element of
> + * the "Usage Table"
> + */
> +struct axiom_usage_entry {
> +       u8 id;
> +       u8 is_report;
> +       u8 start_page;
> +       u8 num_pages;
> +};
> +
> +/*
> + * Represents state of a touch or target when detected prior a touch (eg.
> + * hover or proximity events).
> + */
> +enum axiom_target_state {
> +       AXIOM_TARGET_STATE_NOT_PRESENT = 0,
> +       AXIOM_TARGET_STATE_PROX = 1,
> +       AXIOM_TARGET_STATE_HOVER = 2,
> +       AXIOM_TARGET_STATE_TOUCHING = 3,
> +};
> +
> +struct axiom_u41_target {
> +       enum axiom_target_state state;
> +       u16 x;
> +       u16 y;
> +       s8 z;
> +       bool insert;
> +       bool touch;
> +};
> +
> +struct axiom_target_report {
> +       u8 index;
> +       u8 present;
> +       u16 x;
> +       u16 y;
> +       s8 z;
> +};
> +
> +struct axiom_cmd_header {
> +       __le16 target_address;
> +       __le16 length;
> +} __packed;
> +
> +struct axiom_data {
> +       struct axiom_devinfo devinfo;
> +       struct device *dev;
> +       struct gpio_desc *reset_gpio;
> +       struct i2c_client *client;
> +       struct input_dev *input_dev;
> +       u32 max_report_len;
> +       char rx_buf[AXIOM_COMMS_MAX_USAGE_PAGES * AXIOM_COMMS_PAGE_SIZE];
> +       struct axiom_u41_target targets[AXIOM_U41_MAX_TARGETS];
> +       struct axiom_usage_entry usage_table[AXIOM_U31_MAX_USAGES];
> +       bool usage_table_populated;
> +       struct regulator *vdda;
> +       struct regulator *vddi;
> +};
> +
> +/*
> + * axiom devices are typically configured to report
> + * touches at a rate of 100Hz (10ms). For systems
> + * that require polling for reports.
> + * When reports are polled, it will be expected to
> + * occasionally observe the overflow bit being set
> + * in the reports. This indicates that reports are not
> + * being read fast enough.
> + */
> +#define POLL_INTERVAL_DEFAULT_MS 10
> +
> +/* Translate usage/page/offset triplet into physical address. */
> +static u16 axiom_usage_to_target_address(struct axiom_data *ts, char usage, char page,
> +                                        char offset)
> +{
> +       struct axiom_usage_entry *usage_table;
> +       struct axiom_devinfo *device_info;
> +       u32 i;
> +
> +       device_info = &ts->devinfo;
> +       usage_table = ts->usage_table;
> +
> +       /* At the moment the convention is that u31 is always at physical address 0x0 */
> +       if (!ts->usage_table_populated) {
> +               if (usage == AXIOM_DEVINFO_USAGE_ID)
> +                       return ((page << 8) + offset);
> +               else
> +                       return 0xffff;
> +       }
> +
> +       for (i = 0; i < ts->devinfo.num_usages; i++) {
> +               if (usage_table[i].id != usage)
> +                       continue;
> +
> +               if (page >= usage_table[i].num_pages) {
> +                       dev_err(ts->dev, "Invalid usage table! usage: %u, page: %u, offset: %u\n",
> +                               usage, page, offset);
> +                       return 0xffff;
> +               }
> +               break;
> +       }
> +
> +       return ((usage_table[i].start_page + page) << 8) + offset;
> +}
> +
> +static int axiom_i2c_read(struct i2c_client *client, u8 usage, u8 page, u8 *buf, u16 len)
> +{
> +       struct axiom_data *ts = i2c_get_clientdata(client);
> +       struct axiom_cmd_header cmd_header;
> +       u8 buffer[sizeof(cmd_header) + AXIOM_COMMS_PAGE_SIZE];
> +       struct i2c_msg msg;
> +       int error;
> +
> +       cmd_header.target_address = cpu_to_le16(axiom_usage_to_target_address(ts, usage, page, 0));
> +       cmd_header.length = cpu_to_le16(len | AXIOM_CMD_HEADER_READ_MASK);
> +
> +       memcpy(&buffer[0], &cmd_header, sizeof(cmd_header));
> +       memcpy(&buffer[sizeof(cmd_header)], buf, len);

You're copying a buffer that is meant to hold the response which makes 
no sense.
Please stick to the original implementation which transfers 2 messages :
- first is the header (you're telling the controller what you want to 
read) : this is a write and flags should be 0.
- second is the actual read message : flags should be I2C_M_RD

> +
> +       msg.addr = client->addr;
> +       msg.flags = 0;
> +       msg.len = len + sizeof(cmd_header);
> +       msg.buf = (u8 *)buffer;
> +
> +       error = i2c_transfer(client->adapter, &msg, 1);
> +       if (error != 1) {
You should transfer 2 messages (see above).
> +               dev_err(&client->dev,
> +                       "Failed reading usage %#x page %#x, error=%d\n",
> +                       usage, page, error);
> +               return error;
> +       }
> +
> +       usleep_range(100, 250);
The delay here is not enough as Touchnetix confirmed that we would need 
250 usecs for the controller's internal DMA to be ready after an i2c 
transfer.
> +
> +       return 0;
> +}
> +
> +/*
> + * One of the main purposes for reading the usage table is to identify
> + * which usages reside at which TA address.
> + * When performing subsequent reads or writes to AXIOM, the TA is used
> + * to specify which usage is being accessed.
> + * Consider the following discovery code which will build up the usage table.
> + */
> +static u32 axiom_populate_usage_table(struct axiom_data *ts)
> +{
> +       struct axiom_usage_entry *usage_table;
> +       u32 max_report_len = 0;
> +       char *rx_data = ts->rx_buf;
> +       u32 usage_id;
> +       int error;
> +
> +       usage_table = ts->usage_table;
> +
> +       /* Read the second page of usage u31 to get the usage table */
> +       error = axiom_i2c_read(ts->client, AXIOM_DEVINFO_USAGE_ID, 1, rx_data,
> +                              (AXIOM_U31_BYTES_PER_USAGE * ts->devinfo.num_usages));
> +       if (error)
> +               return error;
> +
> +       for (usage_id = 0; usage_id < ts->devinfo.num_usages; usage_id++) {
> +               u16 offset = (usage_id * AXIOM_U31_BYTES_PER_USAGE);
> +               u8 id = rx_data[offset + 0];
> +               u8 start_page = rx_data[offset + 1];
> +               u8 num_pages = rx_data[offset + 2];
> +               u32 max_offset = ((rx_data[offset + 3] & AXIOM_PAGE_OFFSET_MASK) + 1) * 2;
> +
> +               if (!num_pages)
> +                       usage_table[usage_id].is_report = true;
> +
> +               /* Store the entry into the usage table */
> +               usage_table[usage_id].id = id;
> +               usage_table[usage_id].start_page = start_page;
> +               usage_table[usage_id].num_pages = num_pages;
> +
> +               dev_dbg(ts->dev, "Usage u%02x Info: %*ph\n", id,
> +                       AXIOM_U31_BYTES_PER_USAGE, &rx_data[offset]);
> +
> +               /* Identify the max report length the module will receive */
> +               if (usage_table[usage_id].is_report && max_offset > max_report_len)
> +                       max_report_len = max_offset;
> +       }
> +
> +       ts->usage_table_populated = true;
> +
> +       return max_report_len;
> +}
> +
> +static int axiom_discover(struct axiom_data *ts)
> +{
> +       int error;
> +
> +       /*
> +        * Fetch the first page of usage u31 to get the
> +        * device information and the number of usages
> +        */
> +       error = axiom_i2c_read(ts->client, AXIOM_DEVINFO_USAGE_ID, 0, (char *)&ts->devinfo,
> +                              AXIOM_U31_PAGE0_LENGTH);
> +       if (error)
> +               return error;
> +
> +       dev_dbg(ts->dev, "  Boot Mode      : %s\n",
> +               FIELD_GET(AXIOM_U31_BOOTMODE_MASK, ts->devinfo.device_id) ? "BLP" : "TCP");
> +       dev_dbg(ts->dev, "  Device ID      : %04lx\n",
> +               FIELD_GET(AXIOM_U31_DEVID_MASK, ts->devinfo.device_id));
> +       dev_dbg(ts->dev, "  Firmware Rev   : %02x.%02x\n", ts->devinfo.fw_major,
> +               ts->devinfo.fw_minor);
> +       dev_dbg(ts->dev, "  Bootloader Rev : %02x.%02x\n", ts->devinfo.bootloader_fw_major,
> +               ts->devinfo.bootloader_fw_minor);
> +       dev_dbg(ts->dev, "  FW Extra Info  : %04x\n", ts->devinfo.fw_info_extra);
> +       dev_dbg(ts->dev, "  Silicon        : %04x\n", ts->devinfo.jedec_id);
> +       dev_dbg(ts->dev, "  Number usages        : %04x\n", ts->devinfo.num_usages);
> +
> +       ts->max_report_len = axiom_populate_usage_table(ts);
> +       if (!ts->max_report_len || !ts->devinfo.num_usages)
> +               return -EINVAL;
> +
> +       dev_dbg(ts->dev, "Max Report Length: %u\n", ts->max_report_len);
> +
> +       return 0;
> +}
> +
> +/*
> + * Support function to axiom_process_u41_report.
> + * Generates input-subsystem events for every target.
> + * After calling this function the caller shall issue
> + * a Sync to the input sub-system.
> + */
> +static bool axiom_process_u41_report_target(struct axiom_data *ts,
> +                                           struct axiom_target_report *target)
> +{
> +       struct input_dev *input_dev = ts->input_dev;
> +       struct axiom_u41_target *target_prev_state;
> +       enum axiom_target_state current_state;
> +       bool update = false;
> +       int slot;
> +
> +       /* Verify the target index */
> +       if (target->index >= AXIOM_U41_MAX_TARGETS) {
> +               dev_dbg(ts->dev, "Invalid target index! %u\n", target->index);
> +               return false;
> +       }
> +
> +       target_prev_state = &ts->targets[target->index];
> +
> +       current_state = AXIOM_TARGET_STATE_NOT_PRESENT;
> +
> +       if (target->present) {
> +               if (target->z >= 0)
> +                       current_state = AXIOM_TARGET_STATE_TOUCHING;
> +               else if (target->z > AXIOM_PROX_LEVEL && target->z < 0)
> +                       current_state = AXIOM_TARGET_STATE_HOVER;
> +               else if (target->z == AXIOM_PROX_LEVEL)
> +                       current_state = AXIOM_TARGET_STATE_PROX;
> +       }
> +
> +       if (target_prev_state->state == current_state &&
> +           target_prev_state->x == target->x &&
> +           target_prev_state->y == target->y &&
> +           target_prev_state->z == target->z) {
> +               return false;
> +       }
> +
> +       slot = target->index;
> +
> +       dev_dbg(ts->dev, "U41 Target T%u, slot:%u present:%u, x:%u, y:%u, z:%d\n",
> +               target->index, slot, target->present,
> +               target->x, target->y, target->z);
> +
> +       switch (current_state) {
> +       case AXIOM_TARGET_STATE_NOT_PRESENT:
> +       case AXIOM_TARGET_STATE_PROX:
> +               if (!target_prev_state->insert)
> +                       break;
> +               update = true;
> +               target_prev_state->insert = false;
> +               input_mt_slot(input_dev, slot);
> +
> +               if (!slot)
> +                       input_report_key(input_dev, BTN_TOUCH, 0);
> +
> +               input_mt_report_slot_inactive(input_dev);
> +               /*
> +                * make sure the previous coordinates are
> +                * all off screen when the finger comes back
> +                */
> +               target->x = 65535;
> +               target->y = 65535;
> +               target->z = AXIOM_PROX_LEVEL;
> +               break;
> +       case AXIOM_TARGET_STATE_HOVER:
> +       case AXIOM_TARGET_STATE_TOUCHING:
> +               target_prev_state->insert = true;
> +               update = true;
> +               input_mt_slot(input_dev, slot);
> +               input_report_abs(input_dev, ABS_MT_TRACKING_ID, slot);
> +               input_report_abs(input_dev, ABS_MT_POSITION_X, target->x);
> +               input_report_abs(input_dev, ABS_X, target->x);
> +               input_report_abs(input_dev, ABS_MT_POSITION_Y, target->y);
> +               input_report_abs(input_dev, ABS_Y, target->y);
> +
> +               if (current_state == AXIOM_TARGET_STATE_TOUCHING) {
> +                       input_report_abs(input_dev, ABS_MT_DISTANCE, 0);
> +                       input_report_abs(input_dev, ABS_DISTANCE, 0);
> +                       input_report_abs(input_dev, ABS_MT_PRESSURE, target->z);
> +                       input_report_abs(input_dev, ABS_PRESSURE, target->z);
> +               } else {
> +                       input_report_abs(input_dev, ABS_MT_DISTANCE, -target->z);
> +                       input_report_abs(input_dev, ABS_DISTANCE, -target->z);
> +                       input_report_abs(input_dev, ABS_MT_PRESSURE, 0);
> +                       input_report_abs(input_dev, ABS_PRESSURE, 0);
> +               }
> +
> +               if (!slot)
> +                       input_report_key(input_dev, BTN_TOUCH, (current_state ==
> +                                        AXIOM_TARGET_STATE_TOUCHING));
> +               break;
> +       default:
> +               break;
> +       }
> +
> +       target_prev_state->state = current_state;
> +       target_prev_state->x = target->x;
> +       target_prev_state->y = target->y;
> +       target_prev_state->z = target->z;
> +
> +       return update;
> +}
> +
> +/*
> + * U41 is the output report of the 2D CTS and contains the status of targets
> + * (including contacts and pre-contacts) along with their X,Y,Z values.
> + * When a target has been removed (no longer detected),
> + * the corresponding X,Y,Z values will be zeroed.
> + */
> +static bool axiom_process_u41_report(struct axiom_data *ts, char *rx_buf)
> +{
> +       struct axiom_target_report target;
> +       bool update_done = false;
> +       u16 target_status;
> +       u32 i;
> +
> +       target_status = ((rx_buf[1]) | (rx_buf[2] << 8));
> +
> +       for (i = 0; i < AXIOM_U41_MAX_TARGETS; i++) {
> +               char target_step = i * 4;
> +
> +               target.index = i;
> +               target.present = ((target_status & (1 << i)) != 0) ? 1 : 0;
> +               target.x = (rx_buf[(target_step + 3)] | (rx_buf[target_step + 4] << 8));
> +               target.y = (rx_buf[(target_step + 5)] | (rx_buf[target_step + 6] << 8));
> +               target.z = (s8)(rx_buf[i + 43]);
> +               update_done |= axiom_process_u41_report_target(ts, &target);
> +       }
> +
> +       return update_done;
> +}
> +
> +/*
> + * U46 report contains a low level measurement data generated by the CDS
> + * algorithms from the AUX channels. This information is useful when tuning
> + * multi-press to assess mechanical consistency in the unit's construction.
> + */
> +static void axiom_process_u46_report(struct axiom_data *ts, char *rx_buf)
> +{
> +       struct input_dev *input_dev = ts->input_dev;
> +       u32 event_value;
> +       u16 aux_value;
> +       u32 i = 0;
> +
> +       for (i = 0; i < AXIOM_U46_AUX_CHANNELS; i++) {
> +               char target_step = i * 2;
> +
> +               aux_value = ((rx_buf[target_step + 2] << 8) | (rx_buf[target_step + 1]))
> +                            & AXIOM_U46_AUX_MASK;
> +               event_value = (i << 16) | (aux_value);
> +               input_event(input_dev, EV_MSC, MSC_RAW, event_value);
> +       }
> +}
> +
> +/*
> + * Validates the crc and demultiplexes the axiom reports to the appropriate
> + * report handler
> + */
> +static int axiom_handle_events(struct axiom_data *ts)
> +{
> +       struct input_dev *input_dev = ts->input_dev;
> +       char *report_data = ts->rx_buf;
> +       char report_len;
> +       struct device *dev = ts->dev;
> +       u16 crc_report;
> +       u16 crc_calc;
> +       int error;
> +
> +       error = axiom_i2c_read(ts->client, AXIOM_REPORT_USAGE_ID, 0, &report_len,
> +                              sizeof(report_len));

I know that I told you it would be better to do the read report in 2 
phases, but we should have stick to Touchnetix recommendation that is to 
read the whole report even if it's padded with zeroes.
This is to avoid the 250 usecs delay after the read of the report length.

> +       if (error)
> +               return error;
> +
> +       report_len = (report_len & AXIOM_COMMS_REPORT_LEN_MASK) << 1;
> +       if (!report_len) {
> +               dev_err(dev, "Zero length report discarded\n");
> +               return -ENODATA;
> +       }
> +
> +       error = axiom_i2c_read(ts->client, AXIOM_REPORT_USAGE_ID, 0, report_data, report_len);
> +       if (error)
> +               return error;
> +
> +       /* Validate the report CRC */
> +       crc_report = (report_data[report_len - 1] << 8) | (report_data[report_len - 2]);
> +       /* Length is in 16 bit words and remove the size of the CRC16 itself */
> +       crc_calc = crc16(0, report_data, (report_len - 2));
> +
> +       if (crc_calc != crc_report) {
> +               dev_err(dev,
> +                       "CRC mismatch! Expected: %#x, Calculated CRC: %#x.\n",
> +                       crc_report, crc_calc);
> +               return -EINVAL;
> +       }
> +
> +       switch (report_data[1]) {
> +       case AXIOM_USAGE_2DCTS_REPORT_ID:
> +               if (axiom_process_u41_report(ts, &report_data[1])) {
> +                       input_mt_sync_frame(input_dev);
> +                       input_sync(input_dev);
> +               }
> +               break;
> +
> +       case AXIOM_USAGE_2AUX_REPORT_ID:
> +               /* This is an aux report (force) */
> +               axiom_process_u46_report(ts, &report_data[1]);
> +               input_mt_sync(input_dev);
> +               input_sync(input_dev);
> +               break;
> +
> +       case AXIOM_USAGE_2HB_REPORT_ID:
> +               /* This is a heartbeat report */
> +               break;
> +       default:
> +               return -EINVAL;
> +       }
> +
> +       return 0;
> +}
> +
> +static void axiom_i2c_poll(struct input_dev *input_dev)
> +{
> +       struct axiom_data *ts = input_get_drvdata(input_dev);
> +
> +       axiom_handle_events(ts);
> +}
> +
> +static irqreturn_t axiom_irq(int irq, void *dev_id)
> +{
> +       struct axiom_data *ts = dev_id;
> +
> +       axiom_handle_events(ts);
> +
> +       return IRQ_HANDLED;
> +}
> +
> +static void axiom_reset(struct gpio_desc *reset_gpio)
> +{
> +       gpiod_set_value_cansleep(reset_gpio, 1);
> +       usleep_range(1000, 2000);
> +       gpiod_set_value_cansleep(reset_gpio, 0);
> +       msleep(110);
> +}
> +
> +static int axiom_i2c_probe(struct i2c_client *client)
> +{
> +       struct device *dev = &client->dev;
> +       struct input_dev *input_dev;
> +       struct axiom_data *ts;
> +       u32 startup_delay_ms;
> +       u32 poll_interval;
> +       int target;
> +       int error;
> +
> +       ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
> +       if (!ts)
> +               return -ENOMEM;
> +
> +       ts->client = client;
> +       i2c_set_clientdata(client, ts);
> +       ts->dev = dev;
> +
> +       ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
> +       if (IS_ERR(ts->reset_gpio))
> +               return dev_err_probe(dev, PTR_ERR(ts->reset_gpio), "failed to get reset GPIO\n");
> +
> +       if (ts->reset_gpio)
> +               axiom_reset(ts->reset_gpio);
> +
> +       ts->vddi = devm_regulator_get_optional(dev, "VDDI");
> +       if (!IS_ERR(ts->vddi)) {
> +               error = regulator_enable(ts->vddi);
> +               if (error)
> +                       return dev_err_probe(&client->dev, PTR_ERR(ts->vddi),
> +                                            "Failed to enable VDDI regulator\n");
> +       }
> +
> +       ts->vdda = devm_regulator_get_optional(dev, "VDDA");
> +       if (!IS_ERR(ts->vdda)) {
> +               error = regulator_enable(ts->vdda);
> +               if (error) {
> +                       dev_err(dev, "Failed to get VDDA regulator\n");
> +                       regulator_disable(ts->vddi);
> +                       return error;
> +               }
> +               if (!device_property_read_u32(dev, "startup-time-ms", &startup_delay_ms))
> +                       msleep(startup_delay_ms);
> +       }
> +
> +       error = axiom_discover(ts);
> +       if (error)
> +               return dev_err_probe(dev, error, "Failed touchscreen discover\n");
> +
> +       input_dev = devm_input_allocate_device(ts->dev);
> +       if (!input_dev)
> +               return -ENOMEM;
> +
> +       input_dev->name = "TouchNetix axiom Touchscreen";
> +       input_dev->phys = "input/axiom_ts";
> +
> +       /* Single Touch */
> +       input_set_abs_params(input_dev, ABS_X, 0, 65535, 0, 0);
> +       input_set_abs_params(input_dev, ABS_Y, 0, 65535, 0, 0);
> +
> +       /* Multi Touch */
> +       /* Min, Max, Fuzz (expected noise in px, try 4?) and Flat */
> +       input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0, 65535, 0, 0);
> +       /* Min, Max, Fuzz (expected noise in px, try 4?) and Flat */
> +       input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0, 65535, 0, 0);
> +       input_set_abs_params(input_dev, ABS_MT_TOOL_TYPE, 0, MT_TOOL_MAX, 0, 0);
> +       input_set_abs_params(input_dev, ABS_MT_DISTANCE, 0, 127, 0, 0);
> +       input_set_abs_params(input_dev, ABS_MT_PRESSURE, 0, 127, 0, 0);
> +
> +       input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
> +
> +       /* Registers the axiom device as a touchscreen instead of a mouse pointer */
> +       error = input_mt_init_slots(input_dev, AXIOM_U41_MAX_TARGETS, INPUT_MT_DIRECT);
> +       if (error)
> +               return error;
> +
> +       /* Enables the raw data for up to 4 force channels to be sent to the input subsystem */
> +       set_bit(EV_REL, input_dev->evbit);
> +       set_bit(EV_MSC, input_dev->evbit);
> +       /* Declare that we support "RAW" Miscellaneous events */
> +       set_bit(MSC_RAW, input_dev->mscbit);
> +
> +       ts->input_dev = input_dev;
> +       input_set_drvdata(ts->input_dev, ts);
> +
> +       /* Ensure that all reports are initialised to not be present. */
> +       for (target = 0; target < AXIOM_U41_MAX_TARGETS; target++)
> +               ts->targets[target].state = AXIOM_TARGET_STATE_NOT_PRESENT;
> +
> +       error = input_register_device(input_dev);
> +       if (error)
> +               return dev_err_probe(ts->dev, error,
> +                                    "Could not register with Input Sub-system.\n");
> +
> +       error = devm_request_threaded_irq(dev, client->irq, NULL,
> +                                         axiom_irq, IRQF_ONESHOT, dev_name(dev), ts);
> +       if (error < 0) {
> +               dev_warn(dev, "Request irq failed, falling back to polling mode");
> +
> +               error = input_setup_polling(input_dev, axiom_i2c_poll);
> +               if (error)
> +                       return dev_err_probe(ts->dev, error, "Unable to set up polling mode\n");
> +
> +               if (!device_property_read_u32(ts->dev, "poll-interval", &poll_interval))
> +                       input_set_poll_interval(input_dev, poll_interval);
> +               else
> +                       input_set_poll_interval(input_dev, POLL_INTERVAL_DEFAULT_MS);
> +       }
> +
> +       return 0;
> +}
> +
> +static const struct i2c_device_id axiom_i2c_id_table[] = {
> +       { "ax54a" },
> +       {},
> +};
> +MODULE_DEVICE_TABLE(i2c, axiom_i2c_id_table);
> +
> +static const struct of_device_id axiom_i2c_of_match[] = {
> +       { .compatible = "touchnetix,ax54a", },
> +       { }
> +};
> +MODULE_DEVICE_TABLE(of, axiom_i2c_of_match);
> +
> +static struct i2c_driver axiom_i2c_driver = {
> +       .driver = {
> +                  .name = "axiom",
> +                  .of_match_table = axiom_i2c_of_match,
> +       },
> +       .id_table = axiom_i2c_id_table,
> +       .probe = axiom_i2c_probe,
> +};
> +module_i2c_driver(axiom_i2c_driver);
> +MODULE_AUTHOR("Bart Prescott <bartp@baasheep.co.uk>");
> +MODULE_AUTHOR("Pedro Torruella <pedro.torruella@touchnetix.com>");
> +MODULE_AUTHOR("Mark Satterthwaite <mark.satterthwaite@touchnetix.com>");
> +MODULE_AUTHOR("Hannah Rossiter <hannah.rossiter@touchnetix.com>");
> +MODULE_AUTHOR("Kamel Bouhara <kamel.bouhara@bootlin.com>");
> +MODULE_DESCRIPTION("TouchNetix axiom touchscreen I2C bus driver");
> +MODULE_LICENSE("GPL");
> --
> 2.25.1
>

Re: [PATCH v4 3/3] Input: Add TouchNetix axiom i2c touchscreen driver

[Kamel Bouhara]

Le Mon, Dec 04, 2023 at 03:09:58PM +0000, POPESCU Catalin a écrit :
> On 04.12.23 15:05, Kamel Bouhara wrote:
> > This email is not from Hexagon’s Office 365 instance. Please be careful while clicking links, opening attachments, or replying to this email.
> >
> >
> > Add a new driver for the TouchNetix's axiom family of
> > touchscreen controllers. This driver only supports i2c
> > and can be later adapted for SPI and USB support.
> >
> > Signed-off-by: Kamel Bouhara <kamel.bouhara@bootlin.com>
> > ---
> >   MAINTAINERS                                  |   1 +
> >   drivers/input/touchscreen/Kconfig            |  12 +
> >   drivers/input/touchscreen/Makefile           |   1 +
> >   drivers/input/touchscreen/touchnetix_axiom.c | 675 +++++++++++++++++++
> >   4 files changed, 689 insertions(+)
> >   create mode 100644 drivers/input/touchscreen/touchnetix_axiom.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 4752d8436dbb..337ddac6c74b 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -21436,6 +21436,7 @@ M:      Kamel Bouhara <kamel.bouhara@bootlin.com>
> >   L:     linux-input@vger.kernel.org
> >   S:     Maintained
> >   F:     Documentation/devicetree/bindings/input/touchscreen/touchnetix,ax54a.yaml
> > +F:     drivers/input/touchscreen/touchnetix_axiom.c
> >
> >   THUNDERBOLT DMA TRAFFIC TEST DRIVER
> >   M:     Isaac Hazan <isaac.hazan@intel.com>
> > diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> > index e3e2324547b9..f36bee8d8696 100644
> > --- a/drivers/input/touchscreen/Kconfig
> > +++ b/drivers/input/touchscreen/Kconfig
> > @@ -803,6 +803,18 @@ config TOUCHSCREEN_MIGOR
> >            To compile this driver as a module, choose M here: the
> >            module will be called migor_ts.
> >
> > +config TOUCHSCREEN_TOUCHNETIX_AXIOM
> > +       tristate "TouchNetix AXIOM based touchscreen controllers"
> > +       depends on I2C
> > +       help
> > +         Say Y here if you have a axiom touchscreen connected to
> > +         your system.
> > +
> > +         If unsure, say N.
> > +
> > +         To compile this driver as a module, choose M here: the
> > +         module will be called axiom.
> > +
> >   config TOUCHSCREEN_TOUCHRIGHT
> >          tristate "Touchright serial touchscreen"
> >          select SERIO
> > diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
> > index 62bd24f3ac8e..8e32a2df5e18 100644
> > --- a/drivers/input/touchscreen/Makefile
> > +++ b/drivers/input/touchscreen/Makefile
> > @@ -88,6 +88,7 @@ obj-$(CONFIG_TOUCHSCREEN_SUR40)               += sur40.o
> >   obj-$(CONFIG_TOUCHSCREEN_SURFACE3_SPI) += surface3_spi.o
> >   obj-$(CONFIG_TOUCHSCREEN_TI_AM335X_TSC)        += ti_am335x_tsc.o
> >   obj-$(CONFIG_TOUCHSCREEN_TOUCHIT213)   += touchit213.o
> > +obj-$(CONFIG_TOUCHSCREEN_TOUCHNETIX_AXIOM)     += touchnetix_axiom.o
> >   obj-$(CONFIG_TOUCHSCREEN_TOUCHRIGHT)   += touchright.o
> >   obj-$(CONFIG_TOUCHSCREEN_TOUCHWIN)     += touchwin.o
> >   obj-$(CONFIG_TOUCHSCREEN_TS4800)       += ts4800-ts.o
> > diff --git a/drivers/input/touchscreen/touchnetix_axiom.c b/drivers/input/touchscreen/touchnetix_axiom.c
> > new file mode 100644
> > index 000000000000..9783e89f9e3a
> > --- /dev/null
> > +++ b/drivers/input/touchscreen/touchnetix_axiom.c
> > @@ -0,0 +1,675 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * TouchNetix axiom Touchscreen Driver
> > + *
> > + * Copyright (C) 2020-2023 TouchNetix Ltd.
> > + *
> > + * Author(s): Bart Prescott <bartp@baasheep.co.uk>
> > + *            Pedro Torruella <pedro.torruella@touchnetix.com>
> > + *            Mark Satterthwaite <mark.satterthwaite@touchnetix.com>
> > + *            Hannah Rossiter <hannah.rossiter@touchnetix.com>
> > + *            Kamel Bouhara <kamel.bouhara@bootlin.com>
> > + *
> > + */
> > +#include <linux/bitfield.h>
> > +#include <linux/crc16.h>
> > +#include <linux/delay.h>
> > +#include <linux/device.h>
> > +#include <linux/gpio/consumer.h>
> > +#include <linux/i2c.h>
> > +#include <linux/input.h>
> > +#include <linux/input/mt.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/of.h>
> > +
> > +#define AXIOM_PROX_LEVEL               -128
> > +/*
> > + * Register group u31 has 2 pages for usage table entries.
> > + */
> > +#define AXIOM_U31_MAX_USAGES           ((2 * AXIOM_COMMS_PAGE_SIZE) / AXIOM_U31_BYTES_PER_USAGE)
> > +#define AXIOM_U31_BYTES_PER_USAGE      6
> > +#define AXIOM_U31_PAGE0_LENGTH         0x0C
> > +#define AXIOM_U31_BOOTMODE_MASK                BIT(7)
> > +#define AXIOM_U31_DEVID_MASK           GENMASK(14, 0)
> > +
> > +#define AXIOM_CMD_HEADER_READ_MASK     BIT(15)
> > +#define AXIOM_U41_MAX_TARGETS          10
> > +
> > +#define AXIOM_U46_AUX_CHANNELS         4
> > +#define AXIOM_U46_AUX_MASK             GENMASK(11, 0)
> > +
> > +#define AXIOM_COMMS_MAX_USAGE_PAGES    3
> > +#define AXIOM_COMMS_PAGE_SIZE          256
> > +#define AXIOM_COMMS_REPORT_LEN_MASK    GENMASK(6, 0)
> > +
> > +#define AXIOM_REPORT_USAGE_ID          0x34
> > +#define AXIOM_DEVINFO_USAGE_ID         0x31
> > +#define AXIOM_USAGE_2HB_REPORT_ID      0x01
> > +#define AXIOM_USAGE_2AUX_REPORT_ID     0x46
> > +#define AXIOM_USAGE_2DCTS_REPORT_ID    0x41
> > +
> > +#define AXIOM_PAGE_OFFSET_MASK         GENMASK(6, 0)
> > +
> > +struct axiom_devinfo {
> > +       u16 device_id;
> > +       u8 fw_minor;
> > +       u8 fw_major;
> > +       u8 fw_info_extra;
> > +       u8 tcp_revision;
> > +       u8 bootloader_fw_minor;
> > +       u8 bootloader_fw_major;
> > +       u16 jedec_id;
> > +       u8 num_usages;
> > +} __packed;
> > +
> > +/*
> > + * Describes parameters of a specific usage, essentially a single element of
> > + * the "Usage Table"
> > + */
> > +struct axiom_usage_entry {
> > +       u8 id;
> > +       u8 is_report;
> > +       u8 start_page;
> > +       u8 num_pages;
> > +};
> > +
> > +/*
> > + * Represents state of a touch or target when detected prior a touch (eg.
> > + * hover or proximity events).
> > + */
> > +enum axiom_target_state {
> > +       AXIOM_TARGET_STATE_NOT_PRESENT = 0,
> > +       AXIOM_TARGET_STATE_PROX = 1,
> > +       AXIOM_TARGET_STATE_HOVER = 2,
> > +       AXIOM_TARGET_STATE_TOUCHING = 3,
> > +};
> > +
> > +struct axiom_u41_target {
> > +       enum axiom_target_state state;
> > +       u16 x;
> > +       u16 y;
> > +       s8 z;
> > +       bool insert;
> > +       bool touch;
> > +};
> > +
> > +struct axiom_target_report {
> > +       u8 index;
> > +       u8 present;
> > +       u16 x;
> > +       u16 y;
> > +       s8 z;
> > +};
> > +
> > +struct axiom_cmd_header {
> > +       __le16 target_address;
> > +       __le16 length;
> > +} __packed;
> > +
> > +struct axiom_data {
> > +       struct axiom_devinfo devinfo;
> > +       struct device *dev;
> > +       struct gpio_desc *reset_gpio;
> > +       struct i2c_client *client;
> > +       struct input_dev *input_dev;
> > +       u32 max_report_len;
> > +       char rx_buf[AXIOM_COMMS_MAX_USAGE_PAGES * AXIOM_COMMS_PAGE_SIZE];
> > +       struct axiom_u41_target targets[AXIOM_U41_MAX_TARGETS];
> > +       struct axiom_usage_entry usage_table[AXIOM_U31_MAX_USAGES];
> > +       bool usage_table_populated;
> > +       struct regulator *vdda;
> > +       struct regulator *vddi;
> > +};
> > +
> > +/*
> > + * axiom devices are typically configured to report
> > + * touches at a rate of 100Hz (10ms). For systems
> > + * that require polling for reports.
> > + * When reports are polled, it will be expected to
> > + * occasionally observe the overflow bit being set
> > + * in the reports. This indicates that reports are not
> > + * being read fast enough.
> > + */
> > +#define POLL_INTERVAL_DEFAULT_MS 10
> > +
> > +/* Translate usage/page/offset triplet into physical address. */
> > +static u16 axiom_usage_to_target_address(struct axiom_data *ts, char usage, char page,
> > +                                        char offset)
> > +{
> > +       struct axiom_usage_entry *usage_table;
> > +       struct axiom_devinfo *device_info;
> > +       u32 i;
> > +
> > +       device_info = &ts->devinfo;
> > +       usage_table = ts->usage_table;
> > +
> > +       /* At the moment the convention is that u31 is always at physical address 0x0 */
> > +       if (!ts->usage_table_populated) {
> > +               if (usage == AXIOM_DEVINFO_USAGE_ID)
> > +                       return ((page << 8) + offset);
> > +               else
> > +                       return 0xffff;
> > +       }
> > +
> > +       for (i = 0; i < ts->devinfo.num_usages; i++) {
> > +               if (usage_table[i].id != usage)
> > +                       continue;
> > +
> > +               if (page >= usage_table[i].num_pages) {
> > +                       dev_err(ts->dev, "Invalid usage table! usage: %u, page: %u, offset: %u\n",
> > +                               usage, page, offset);
> > +                       return 0xffff;
> > +               }
> > +               break;
> > +       }
> > +
> > +       return ((usage_table[i].start_page + page) << 8) + offset;
> > +}
> > +
> > +static int axiom_i2c_read(struct i2c_client *client, u8 usage, u8 page, u8 *buf, u16 len)
> > +{
> > +       struct axiom_data *ts = i2c_get_clientdata(client);
> > +       struct axiom_cmd_header cmd_header;
> > +       u8 buffer[sizeof(cmd_header) + AXIOM_COMMS_PAGE_SIZE];
> > +       struct i2c_msg msg;
> > +       int error;
> > +
> > +       cmd_header.target_address = cpu_to_le16(axiom_usage_to_target_address(ts, usage, page, 0));
> > +       cmd_header.length = cpu_to_le16(len | AXIOM_CMD_HEADER_READ_MASK);
> > +
> > +       memcpy(&buffer[0], &cmd_header, sizeof(cmd_header));
> > +       memcpy(&buffer[sizeof(cmd_header)], buf, len);
>
> You're copying a buffer that is meant to hold the response which makes
> no sense.
> Please stick to the original implementation which transfers 2 messages :
> - first is the header (you're telling the controller what you want to
> read) : this is a write and flags should be 0.
> - second is the actual read message : flags should be I2C_M_RD

This was not supposed to be applied on read but rather axiom_i2c_write().

Fixed for v5, thanks.

>
> > +
> > +       msg.addr = client->addr;
> > +       msg.flags = 0;
> > +       msg.len = len + sizeof(cmd_header);
> > +       msg.buf = (u8 *)buffer;
> > +
> > +       error = i2c_transfer(client->adapter, &msg, 1);
> > +       if (error != 1) {
> You should transfer 2 messages (see above).
> > +               dev_err(&client->dev,
> > +                       "Failed reading usage %#x page %#x, error=%d\n",
> > +                       usage, page, error);
> > +               return error;
> > +       }
> > +
> > +       usleep_range(100, 250);
> The delay here is not enough as Touchnetix confirmed that we would need
> 250 usecs for the controller's internal DMA to be ready after an i2c
> transfer.

Ok that wasn't clear if it was after 2 consecutives reads but now it is.

Maybe Mark can confirm again ?

> > +
> > +       return 0;
> > +}
> > +
> > +/*
> > + * One of the main purposes for reading the usage table is to identify
> > + * which usages reside at which TA address.
> > + * When performing subsequent reads or writes to AXIOM, the TA is used
> > + * to specify which usage is being accessed.
> > + * Consider the following discovery code which will build up the usage table.
> > + */
> > +static u32 axiom_populate_usage_table(struct axiom_data *ts)
> > +{
> > +       struct axiom_usage_entry *usage_table;
> > +       u32 max_report_len = 0;
> > +       char *rx_data = ts->rx_buf;
> > +       u32 usage_id;
> > +       int error;
> > +
> > +       usage_table = ts->usage_table;
> > +
> > +       /* Read the second page of usage u31 to get the usage table */
> > +       error = axiom_i2c_read(ts->client, AXIOM_DEVINFO_USAGE_ID, 1, rx_data,
> > +                              (AXIOM_U31_BYTES_PER_USAGE * ts->devinfo.num_usages));
> > +       if (error)
> > +               return error;
> > +
> > +       for (usage_id = 0; usage_id < ts->devinfo.num_usages; usage_id++) {
> > +               u16 offset = (usage_id * AXIOM_U31_BYTES_PER_USAGE);
> > +               u8 id = rx_data[offset + 0];
> > +               u8 start_page = rx_data[offset + 1];
> > +               u8 num_pages = rx_data[offset + 2];
> > +               u32 max_offset = ((rx_data[offset + 3] & AXIOM_PAGE_OFFSET_MASK) + 1) * 2;
> > +
> > +               if (!num_pages)
> > +                       usage_table[usage_id].is_report = true;
> > +
> > +               /* Store the entry into the usage table */
> > +               usage_table[usage_id].id = id;
> > +               usage_table[usage_id].start_page = start_page;
> > +               usage_table[usage_id].num_pages = num_pages;
> > +
> > +               dev_dbg(ts->dev, "Usage u%02x Info: %*ph\n", id,
> > +                       AXIOM_U31_BYTES_PER_USAGE, &rx_data[offset]);
> > +
> > +               /* Identify the max report length the module will receive */
> > +               if (usage_table[usage_id].is_report && max_offset > max_report_len)
> > +                       max_report_len = max_offset;
> > +       }
> > +
> > +       ts->usage_table_populated = true;
> > +
> > +       return max_report_len;
> > +}
> > +
> > +static int axiom_discover(struct axiom_data *ts)
> > +{
> > +       int error;
> > +
> > +       /*
> > +        * Fetch the first page of usage u31 to get the
> > +        * device information and the number of usages
> > +        */
> > +       error = axiom_i2c_read(ts->client, AXIOM_DEVINFO_USAGE_ID, 0, (char *)&ts->devinfo,
> > +                              AXIOM_U31_PAGE0_LENGTH);
> > +       if (error)
> > +               return error;
> > +
> > +       dev_dbg(ts->dev, "  Boot Mode      : %s\n",
> > +               FIELD_GET(AXIOM_U31_BOOTMODE_MASK, ts->devinfo.device_id) ? "BLP" : "TCP");
> > +       dev_dbg(ts->dev, "  Device ID      : %04lx\n",
> > +               FIELD_GET(AXIOM_U31_DEVID_MASK, ts->devinfo.device_id));
> > +       dev_dbg(ts->dev, "  Firmware Rev   : %02x.%02x\n", ts->devinfo.fw_major,
> > +               ts->devinfo.fw_minor);
> > +       dev_dbg(ts->dev, "  Bootloader Rev : %02x.%02x\n", ts->devinfo.bootloader_fw_major,
> > +               ts->devinfo.bootloader_fw_minor);
> > +       dev_dbg(ts->dev, "  FW Extra Info  : %04x\n", ts->devinfo.fw_info_extra);
> > +       dev_dbg(ts->dev, "  Silicon        : %04x\n", ts->devinfo.jedec_id);
> > +       dev_dbg(ts->dev, "  Number usages        : %04x\n", ts->devinfo.num_usages);
> > +
> > +       ts->max_report_len = axiom_populate_usage_table(ts);
> > +       if (!ts->max_report_len || !ts->devinfo.num_usages)
> > +               return -EINVAL;
> > +
> > +       dev_dbg(ts->dev, "Max Report Length: %u\n", ts->max_report_len);
> > +
> > +       return 0;
> > +}
> > +
> > +/*
> > + * Support function to axiom_process_u41_report.
> > + * Generates input-subsystem events for every target.
> > + * After calling this function the caller shall issue
> > + * a Sync to the input sub-system.
> > + */
> > +static bool axiom_process_u41_report_target(struct axiom_data *ts,
> > +                                           struct axiom_target_report *target)
> > +{
> > +       struct input_dev *input_dev = ts->input_dev;
> > +       struct axiom_u41_target *target_prev_state;
> > +       enum axiom_target_state current_state;
> > +       bool update = false;
> > +       int slot;
> > +
> > +       /* Verify the target index */
> > +       if (target->index >= AXIOM_U41_MAX_TARGETS) {
> > +               dev_dbg(ts->dev, "Invalid target index! %u\n", target->index);
> > +               return false;
> > +       }
> > +
> > +       target_prev_state = &ts->targets[target->index];
> > +
> > +       current_state = AXIOM_TARGET_STATE_NOT_PRESENT;
> > +
> > +       if (target->present) {
> > +               if (target->z >= 0)
> > +                       current_state = AXIOM_TARGET_STATE_TOUCHING;
> > +               else if (target->z > AXIOM_PROX_LEVEL && target->z < 0)
> > +                       current_state = AXIOM_TARGET_STATE_HOVER;
> > +               else if (target->z == AXIOM_PROX_LEVEL)
> > +                       current_state = AXIOM_TARGET_STATE_PROX;
> > +       }
> > +
> > +       if (target_prev_state->state == current_state &&
> > +           target_prev_state->x == target->x &&
> > +           target_prev_state->y == target->y &&
> > +           target_prev_state->z == target->z) {
> > +               return false;
> > +       }
> > +
> > +       slot = target->index;
> > +
> > +       dev_dbg(ts->dev, "U41 Target T%u, slot:%u present:%u, x:%u, y:%u, z:%d\n",
> > +               target->index, slot, target->present,
> > +               target->x, target->y, target->z);
> > +
> > +       switch (current_state) {
> > +       case AXIOM_TARGET_STATE_NOT_PRESENT:
> > +       case AXIOM_TARGET_STATE_PROX:
> > +               if (!target_prev_state->insert)
> > +                       break;
> > +               update = true;
> > +               target_prev_state->insert = false;
> > +               input_mt_slot(input_dev, slot);
> > +
> > +               if (!slot)
> > +                       input_report_key(input_dev, BTN_TOUCH, 0);
> > +
> > +               input_mt_report_slot_inactive(input_dev);
> > +               /*
> > +                * make sure the previous coordinates are
> > +                * all off screen when the finger comes back
> > +                */
> > +               target->x = 65535;
> > +               target->y = 65535;
> > +               target->z = AXIOM_PROX_LEVEL;
> > +               break;
> > +       case AXIOM_TARGET_STATE_HOVER:
> > +       case AXIOM_TARGET_STATE_TOUCHING:
> > +               target_prev_state->insert = true;
> > +               update = true;
> > +               input_mt_slot(input_dev, slot);
> > +               input_report_abs(input_dev, ABS_MT_TRACKING_ID, slot);
> > +               input_report_abs(input_dev, ABS_MT_POSITION_X, target->x);
> > +               input_report_abs(input_dev, ABS_X, target->x);
> > +               input_report_abs(input_dev, ABS_MT_POSITION_Y, target->y);
> > +               input_report_abs(input_dev, ABS_Y, target->y);
> > +
> > +               if (current_state == AXIOM_TARGET_STATE_TOUCHING) {
> > +                       input_report_abs(input_dev, ABS_MT_DISTANCE, 0);
> > +                       input_report_abs(input_dev, ABS_DISTANCE, 0);
> > +                       input_report_abs(input_dev, ABS_MT_PRESSURE, target->z);
> > +                       input_report_abs(input_dev, ABS_PRESSURE, target->z);
> > +               } else {
> > +                       input_report_abs(input_dev, ABS_MT_DISTANCE, -target->z);
> > +                       input_report_abs(input_dev, ABS_DISTANCE, -target->z);
> > +                       input_report_abs(input_dev, ABS_MT_PRESSURE, 0);
> > +                       input_report_abs(input_dev, ABS_PRESSURE, 0);
> > +               }
> > +
> > +               if (!slot)
> > +                       input_report_key(input_dev, BTN_TOUCH, (current_state ==
> > +                                        AXIOM_TARGET_STATE_TOUCHING));
> > +               break;
> > +       default:
> > +               break;
> > +       }
> > +
> > +       target_prev_state->state = current_state;
> > +       target_prev_state->x = target->x;
> > +       target_prev_state->y = target->y;
> > +       target_prev_state->z = target->z;
> > +
> > +       return update;
> > +}
> > +
> > +/*
> > + * U41 is the output report of the 2D CTS and contains the status of targets
> > + * (including contacts and pre-contacts) along with their X,Y,Z values.
> > + * When a target has been removed (no longer detected),
> > + * the corresponding X,Y,Z values will be zeroed.
> > + */
> > +static bool axiom_process_u41_report(struct axiom_data *ts, char *rx_buf)
> > +{
> > +       struct axiom_target_report target;
> > +       bool update_done = false;
> > +       u16 target_status;
> > +       u32 i;
> > +
> > +       target_status = ((rx_buf[1]) | (rx_buf[2] << 8));
> > +
> > +       for (i = 0; i < AXIOM_U41_MAX_TARGETS; i++) {
> > +               char target_step = i * 4;
> > +
> > +               target.index = i;
> > +               target.present = ((target_status & (1 << i)) != 0) ? 1 : 0;
> > +               target.x = (rx_buf[(target_step + 3)] | (rx_buf[target_step + 4] << 8));
> > +               target.y = (rx_buf[(target_step + 5)] | (rx_buf[target_step + 6] << 8));
> > +               target.z = (s8)(rx_buf[i + 43]);
> > +               update_done |= axiom_process_u41_report_target(ts, &target);
> > +       }
> > +
> > +       return update_done;
> > +}
> > +
> > +/*
> > + * U46 report contains a low level measurement data generated by the CDS
> > + * algorithms from the AUX channels. This information is useful when tuning
> > + * multi-press to assess mechanical consistency in the unit's construction.
> > + */
> > +static void axiom_process_u46_report(struct axiom_data *ts, char *rx_buf)
> > +{
> > +       struct input_dev *input_dev = ts->input_dev;
> > +       u32 event_value;
> > +       u16 aux_value;
> > +       u32 i = 0;
> > +
> > +       for (i = 0; i < AXIOM_U46_AUX_CHANNELS; i++) {
> > +               char target_step = i * 2;
> > +
> > +               aux_value = ((rx_buf[target_step + 2] << 8) | (rx_buf[target_step + 1]))
> > +                            & AXIOM_U46_AUX_MASK;
> > +               event_value = (i << 16) | (aux_value);
> > +               input_event(input_dev, EV_MSC, MSC_RAW, event_value);
> > +       }
> > +}
> > +
> > +/*
> > + * Validates the crc and demultiplexes the axiom reports to the appropriate
> > + * report handler
> > + */
> > +static int axiom_handle_events(struct axiom_data *ts)
> > +{
> > +       struct input_dev *input_dev = ts->input_dev;
> > +       char *report_data = ts->rx_buf;
> > +       char report_len;
> > +       struct device *dev = ts->dev;
> > +       u16 crc_report;
> > +       u16 crc_calc;
> > +       int error;
> > +
> > +       error = axiom_i2c_read(ts->client, AXIOM_REPORT_USAGE_ID, 0, &report_len,
> > +                              sizeof(report_len));
>
> I know that I told you it would be better to do the read report in 2
> phases, but we should have stick to Touchnetix recommendation that is to
> read the whole report even if it's padded with zeroes.
> This is to avoid the 250 usecs delay after the read of the report length.
>

Ack, thanks.

> > +       if (error)
> > +               return error;
> > +
> > +       report_len = (report_len & AXIOM_COMMS_REPORT_LEN_MASK) << 1;
> > +       if (!report_len) {
> > +               dev_err(dev, "Zero length report discarded\n");
> > +               return -ENODATA;
> > +       }
> > +
> > +       error = axiom_i2c_read(ts->client, AXIOM_REPORT_USAGE_ID, 0, report_data, report_len);
> > +       if (error)
> > +               return error;
> > +
> > +       /* Validate the report CRC */
> > +       crc_report = (report_data[report_len - 1] << 8) | (report_data[report_len - 2]);
> > +       /* Length is in 16 bit words and remove the size of the CRC16 itself */
> > +       crc_calc = crc16(0, report_data, (report_len - 2));
> > +
> > +       if (crc_calc != crc_report) {
> > +               dev_err(dev,
> > +                       "CRC mismatch! Expected: %#x, Calculated CRC: %#x.\n",
> > +                       crc_report, crc_calc);
> > +               return -EINVAL;
> > +       }
> > +
> > +       switch (report_data[1]) {
> > +       case AXIOM_USAGE_2DCTS_REPORT_ID:
> > +               if (axiom_process_u41_report(ts, &report_data[1])) {
> > +                       input_mt_sync_frame(input_dev);
> > +                       input_sync(input_dev);
> > +               }
> > +               break;
> > +
> > +       case AXIOM_USAGE_2AUX_REPORT_ID:
> > +               /* This is an aux report (force) */
> > +               axiom_process_u46_report(ts, &report_data[1]);
> > +               input_mt_sync(input_dev);
> > +               input_sync(input_dev);
> > +               break;
> > +
> > +       case AXIOM_USAGE_2HB_REPORT_ID:
> > +               /* This is a heartbeat report */
> > +               break;
> > +       default:
> > +               return -EINVAL;
> > +       }
> > +
> > +       return 0;
> > +}
> > +
> > +static void axiom_i2c_poll(struct input_dev *input_dev)
> > +{
> > +       struct axiom_data *ts = input_get_drvdata(input_dev);
> > +
> > +       axiom_handle_events(ts);
> > +}
> > +
> > +static irqreturn_t axiom_irq(int irq, void *dev_id)
> > +{
> > +       struct axiom_data *ts = dev_id;
> > +
> > +       axiom_handle_events(ts);
> > +
> > +       return IRQ_HANDLED;
> > +}
> > +
> > +static void axiom_reset(struct gpio_desc *reset_gpio)
> > +{
> > +       gpiod_set_value_cansleep(reset_gpio, 1);
> > +       usleep_range(1000, 2000);
> > +       gpiod_set_value_cansleep(reset_gpio, 0);
> > +       msleep(110);
> > +}
> > +
> > +static int axiom_i2c_probe(struct i2c_client *client)
> > +{
> > +       struct device *dev = &client->dev;
> > +       struct input_dev *input_dev;
> > +       struct axiom_data *ts;
> > +       u32 startup_delay_ms;
> > +       u32 poll_interval;
> > +       int target;
> > +       int error;
> > +
> > +       ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
> > +       if (!ts)
> > +               return -ENOMEM;
> > +
> > +       ts->client = client;
> > +       i2c_set_clientdata(client, ts);
> > +       ts->dev = dev;
> > +
> > +       ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
> > +       if (IS_ERR(ts->reset_gpio))
> > +               return dev_err_probe(dev, PTR_ERR(ts->reset_gpio), "failed to get reset GPIO\n");
> > +
> > +       if (ts->reset_gpio)
> > +               axiom_reset(ts->reset_gpio);
> > +
> > +       ts->vddi = devm_regulator_get_optional(dev, "VDDI");
> > +       if (!IS_ERR(ts->vddi)) {
> > +               error = regulator_enable(ts->vddi);
> > +               if (error)
> > +                       return dev_err_probe(&client->dev, PTR_ERR(ts->vddi),
> > +                                            "Failed to enable VDDI regulator\n");
> > +       }
> > +
> > +       ts->vdda = devm_regulator_get_optional(dev, "VDDA");
> > +       if (!IS_ERR(ts->vdda)) {
> > +               error = regulator_enable(ts->vdda);
> > +               if (error) {
> > +                       dev_err(dev, "Failed to get VDDA regulator\n");
> > +                       regulator_disable(ts->vddi);
> > +                       return error;
> > +               }
> > +               if (!device_property_read_u32(dev, "startup-time-ms", &startup_delay_ms))
> > +                       msleep(startup_delay_ms);
> > +       }
> > +
> > +       error = axiom_discover(ts);
> > +       if (error)
> > +               return dev_err_probe(dev, error, "Failed touchscreen discover\n");
> > +
> > +       input_dev = devm_input_allocate_device(ts->dev);
> > +       if (!input_dev)
> > +               return -ENOMEM;
> > +
> > +       input_dev->name = "TouchNetix axiom Touchscreen";
> > +       input_dev->phys = "input/axiom_ts";
> > +
> > +       /* Single Touch */
> > +       input_set_abs_params(input_dev, ABS_X, 0, 65535, 0, 0);
> > +       input_set_abs_params(input_dev, ABS_Y, 0, 65535, 0, 0);
> > +
> > +       /* Multi Touch */
> > +       /* Min, Max, Fuzz (expected noise in px, try 4?) and Flat */
> > +       input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0, 65535, 0, 0);
> > +       /* Min, Max, Fuzz (expected noise in px, try 4?) and Flat */
> > +       input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0, 65535, 0, 0);
> > +       input_set_abs_params(input_dev, ABS_MT_TOOL_TYPE, 0, MT_TOOL_MAX, 0, 0);
> > +       input_set_abs_params(input_dev, ABS_MT_DISTANCE, 0, 127, 0, 0);
> > +       input_set_abs_params(input_dev, ABS_MT_PRESSURE, 0, 127, 0, 0);
> > +
> > +       input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
> > +
> > +       /* Registers the axiom device as a touchscreen instead of a mouse pointer */
> > +       error = input_mt_init_slots(input_dev, AXIOM_U41_MAX_TARGETS, INPUT_MT_DIRECT);
> > +       if (error)
> > +               return error;
> > +
> > +       /* Enables the raw data for up to 4 force channels to be sent to the input subsystem */
> > +       set_bit(EV_REL, input_dev->evbit);
> > +       set_bit(EV_MSC, input_dev->evbit);
> > +       /* Declare that we support "RAW" Miscellaneous events */
> > +       set_bit(MSC_RAW, input_dev->mscbit);
> > +
> > +       ts->input_dev = input_dev;
> > +       input_set_drvdata(ts->input_dev, ts);
> > +
> > +       /* Ensure that all reports are initialised to not be present. */
> > +       for (target = 0; target < AXIOM_U41_MAX_TARGETS; target++)
> > +               ts->targets[target].state = AXIOM_TARGET_STATE_NOT_PRESENT;
> > +
> > +       error = input_register_device(input_dev);
> > +       if (error)
> > +               return dev_err_probe(ts->dev, error,
> > +                                    "Could not register with Input Sub-system.\n");
> > +
> > +       error = devm_request_threaded_irq(dev, client->irq, NULL,
> > +                                         axiom_irq, IRQF_ONESHOT, dev_name(dev), ts);
> > +       if (error < 0) {
> > +               dev_warn(dev, "Request irq failed, falling back to polling mode");
> > +
> > +               error = input_setup_polling(input_dev, axiom_i2c_poll);
> > +               if (error)
> > +                       return dev_err_probe(ts->dev, error, "Unable to set up polling mode\n");
> > +
> > +               if (!device_property_read_u32(ts->dev, "poll-interval", &poll_interval))
> > +                       input_set_poll_interval(input_dev, poll_interval);
> > +               else
> > +                       input_set_poll_interval(input_dev, POLL_INTERVAL_DEFAULT_MS);
> > +       }
> > +
> > +       return 0;
> > +}
> > +
> > +static const struct i2c_device_id axiom_i2c_id_table[] = {
> > +       { "ax54a" },
> > +       {},
> > +};
> > +MODULE_DEVICE_TABLE(i2c, axiom_i2c_id_table);
> > +
> > +static const struct of_device_id axiom_i2c_of_match[] = {
> > +       { .compatible = "touchnetix,ax54a", },
> > +       { }
> > +};
> > +MODULE_DEVICE_TABLE(of, axiom_i2c_of_match);
> > +
> > +static struct i2c_driver axiom_i2c_driver = {
> > +       .driver = {
> > +                  .name = "axiom",
> > +                  .of_match_table = axiom_i2c_of_match,
> > +       },
> > +       .id_table = axiom_i2c_id_table,
> > +       .probe = axiom_i2c_probe,
> > +};
> > +module_i2c_driver(axiom_i2c_driver);
> > +MODULE_AUTHOR("Bart Prescott <bartp@baasheep.co.uk>");
> > +MODULE_AUTHOR("Pedro Torruella <pedro.torruella@touchnetix.com>");
> > +MODULE_AUTHOR("Mark Satterthwaite <mark.satterthwaite@touchnetix.com>");
> > +MODULE_AUTHOR("Hannah Rossiter <hannah.rossiter@touchnetix.com>");
> > +MODULE_AUTHOR("Kamel Bouhara <kamel.bouhara@bootlin.com>");
> > +MODULE_DESCRIPTION("TouchNetix axiom touchscreen I2C bus driver");
> > +MODULE_LICENSE("GPL");
> > --
> > 2.25.1
> >
>

--
Kamel Bouhara, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com

Re: [PATCH v4 3/3] Input: Add TouchNetix axiom i2c touchscreen driver

[kernel test robot]

Hi Kamel,

kernel test robot noticed the following build warnings:

[auto build test WARNING on dtor-input/next]
[also build test WARNING on dtor-input/for-linus robh/for-next linus/master krzk-dt/for-next v6.7-rc4 next-20231204]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Kamel-Bouhara/dt-bindings-vendor-prefixes-Add-TouchNetix-AS/20231204-222017
base:   https://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git next
patch link:    https://lore.kernel.org/r/20231204140505.2838916-4-kamel.bouhara%40bootlin.com
patch subject: [PATCH v4 3/3] Input: Add TouchNetix axiom i2c touchscreen driver
config: alpha-allyesconfig (https://download.01.org/0day-ci/archive/20231205/202312051457.y3N1q3sZ-lkp@intel.com/config)
compiler: alpha-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231205/202312051457.y3N1q3sZ-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202312051457.y3N1q3sZ-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/input/touchscreen/touchnetix_axiom.c: In function 'axiom_usage_to_target_address':
>> drivers/input/touchscreen/touchnetix_axiom.c:142:31: warning: variable 'device_info' set but not used [-Wunused-but-set-variable]
     142 |         struct axiom_devinfo *device_info;
         |                               ^~~~~~~~~~~


vim +/device_info +142 drivers/input/touchscreen/touchnetix_axiom.c

   136	
   137	/* Translate usage/page/offset triplet into physical address. */
   138	static u16 axiom_usage_to_target_address(struct axiom_data *ts, char usage, char page,
   139						 char offset)
   140	{
   141		struct axiom_usage_entry *usage_table;
 > 142		struct axiom_devinfo *device_info;
   143		u32 i;
   144	
   145		device_info = &ts->devinfo;
   146		usage_table = ts->usage_table;
   147	
   148		/* At the moment the convention is that u31 is always at physical address 0x0 */
   149		if (!ts->usage_table_populated) {
   150			if (usage == AXIOM_DEVINFO_USAGE_ID)
   151				return ((page << 8) + offset);
   152			else
   153				return 0xffff;
   154		}
   155	
   156		for (i = 0; i < ts->devinfo.num_usages; i++) {
   157			if (usage_table[i].id != usage)
   158				continue;
   159	
   160			if (page >= usage_table[i].num_pages) {
   161				dev_err(ts->dev, "Invalid usage table! usage: %u, page: %u, offset: %u\n",
   162					usage, page, offset);
   163				return 0xffff;
   164			}
   165			break;
   166		}
   167	
   168		return ((usage_table[i].start_page + page) << 8) + offset;
   169	}
   170	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH v4 3/3] Input: Add TouchNetix axiom i2c touchscreen driver

[Dan Carpenter]

Hi Kamel,

kernel test robot noticed the following build warnings:

https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Kamel-Bouhara/dt-bindings-vendor-prefixes-Add-TouchNetix-AS/20231204-222017
base:   https://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git next
patch link:    https://lore.kernel.org/r/20231204140505.2838916-4-kamel.bouhara%40bootlin.com
patch subject: [PATCH v4 3/3] Input: Add TouchNetix axiom i2c touchscreen driver
config: i386-randconfig-r071-20231206 (https://download.01.org/0day-ci/archive/20231207/202312070608.vxtNAYhk-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce: (https://download.01.org/0day-ci/archive/20231207/202312070608.vxtNAYhk-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202312070608.vxtNAYhk-lkp@intel.com/

smatch warnings:
drivers/input/touchscreen/touchnetix_axiom.c:565 axiom_i2c_probe() warn: passing zero to 'PTR_ERR'

vim +/PTR_ERR +565 drivers/input/touchscreen/touchnetix_axiom.c

a9f3450f06a026 Kamel Bouhara 2023-12-04  536  static int axiom_i2c_probe(struct i2c_client *client)
a9f3450f06a026 Kamel Bouhara 2023-12-04  537  {
a9f3450f06a026 Kamel Bouhara 2023-12-04  538  	struct device *dev = &client->dev;
a9f3450f06a026 Kamel Bouhara 2023-12-04  539  	struct input_dev *input_dev;
a9f3450f06a026 Kamel Bouhara 2023-12-04  540  	struct axiom_data *ts;
a9f3450f06a026 Kamel Bouhara 2023-12-04  541  	u32 startup_delay_ms;
a9f3450f06a026 Kamel Bouhara 2023-12-04  542  	u32 poll_interval;
a9f3450f06a026 Kamel Bouhara 2023-12-04  543  	int target;
a9f3450f06a026 Kamel Bouhara 2023-12-04  544  	int error;
a9f3450f06a026 Kamel Bouhara 2023-12-04  545  
a9f3450f06a026 Kamel Bouhara 2023-12-04  546  	ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
a9f3450f06a026 Kamel Bouhara 2023-12-04  547  	if (!ts)
a9f3450f06a026 Kamel Bouhara 2023-12-04  548  		return -ENOMEM;
a9f3450f06a026 Kamel Bouhara 2023-12-04  549  
a9f3450f06a026 Kamel Bouhara 2023-12-04  550  	ts->client = client;
a9f3450f06a026 Kamel Bouhara 2023-12-04  551  	i2c_set_clientdata(client, ts);
a9f3450f06a026 Kamel Bouhara 2023-12-04  552  	ts->dev = dev;
a9f3450f06a026 Kamel Bouhara 2023-12-04  553  
a9f3450f06a026 Kamel Bouhara 2023-12-04  554  	ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
a9f3450f06a026 Kamel Bouhara 2023-12-04  555  	if (IS_ERR(ts->reset_gpio))
a9f3450f06a026 Kamel Bouhara 2023-12-04  556  		return dev_err_probe(dev, PTR_ERR(ts->reset_gpio), "failed to get reset GPIO\n");
a9f3450f06a026 Kamel Bouhara 2023-12-04  557  
a9f3450f06a026 Kamel Bouhara 2023-12-04  558  	if (ts->reset_gpio)
a9f3450f06a026 Kamel Bouhara 2023-12-04  559  		axiom_reset(ts->reset_gpio);
a9f3450f06a026 Kamel Bouhara 2023-12-04  560  
a9f3450f06a026 Kamel Bouhara 2023-12-04  561  	ts->vddi = devm_regulator_get_optional(dev, "VDDI");
a9f3450f06a026 Kamel Bouhara 2023-12-04  562  	if (!IS_ERR(ts->vddi)) {
a9f3450f06a026 Kamel Bouhara 2023-12-04  563  		error = regulator_enable(ts->vddi);
a9f3450f06a026 Kamel Bouhara 2023-12-04  564  		if (error)
a9f3450f06a026 Kamel Bouhara 2023-12-04 @565  			return dev_err_probe(&client->dev, PTR_ERR(ts->vddi),
                                                                                                   ^^^^^^^^^^^^^^^^^^
s/PTR_ERR(ts->vddi)/error/

a9f3450f06a026 Kamel Bouhara 2023-12-04  566  					     "Failed to enable VDDI regulator\n");
a9f3450f06a026 Kamel Bouhara 2023-12-04  567  	}
a9f3450f06a026 Kamel Bouhara 2023-12-04  568  

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Re: [PATCH v4 3/3] Input: Add TouchNetix axiom i2c touchscreen driver

[kernel test robot]

BCC: lkp@intel.com
CC: oe-kbuild-all@lists.linux.dev
In-Reply-To: <20231204140505.2838916-4-kamel.bouhara@bootlin.com>
References: <20231204140505.2838916-4-kamel.bouhara@bootlin.com>
TO: Kamel Bouhara <kamel.bouhara@bootlin.com>
TO: Dmitry Torokhov <dmitry.torokhov@gmail.com>
TO: Rob Herring <robh+dt@kernel.org>
TO: Krzysztof Kozlowski <krzk@kernel.org>
TO: Conor Dooley <conor+dt@kernel.org>
TO: Henrik Rydberg <rydberg@bitmath.org>
TO: linux-input@vger.kernel.org
TO: linux-kernel@vger.kernel.org
TO: devicetree@vger.kernel.org
TO: Marco Felsch <m.felsch@pengutronix.de>
TO: Jeff LaBundy <jeff@labundy.com>
CC: catalin.popescu@leica-geosystems.com
CC: mark.satterthwaite@touchnetix.com
CC: bartp@baasheep.co.uk
CC: hannah.rossiter@touchnetix.com
CC: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
CC: Gregory Clement <gregory.clement@bootlin.com>
CC: bsp-development.geo@leica-geosystems.com
CC: Kamel Bouhara <kamel.bouhara@bootlin.com>

Hi Kamel,

kernel test robot noticed the following build warnings:

[auto build test WARNING on dtor-input/next]
[also build test WARNING on dtor-input/for-linus robh/for-next linus/master krzk-dt/for-next v6.7-rc4 next-20231206]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Kamel-Bouhara/dt-bindings-vendor-prefixes-Add-TouchNetix-AS/20231204-222017
base:   https://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git next
patch link:    https://lore.kernel.org/r/20231204140505.2838916-4-kamel.bouhara%40bootlin.com
patch subject: [PATCH v4 3/3] Input: Add TouchNetix axiom i2c touchscreen driver
:::::: branch date: 2 days ago
:::::: commit date: 2 days ago
config: i386-randconfig-r071-20231206 (https://download.01.org/0day-ci/archive/20231207/202312070608.vxtNAYhk-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce: (https://download.01.org/0day-ci/archive/20231207/202312070608.vxtNAYhk-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <error27@gmail.com>
| Closes: https://lore.kernel.org/r/202312070608.vxtNAYhk-lkp@intel.com/

smatch warnings:
drivers/input/touchscreen/touchnetix_axiom.c:565 axiom_i2c_probe() warn: passing zero to 'PTR_ERR'

vim +/PTR_ERR +565 drivers/input/touchscreen/touchnetix_axiom.c

a9f3450f06a026 Kamel Bouhara 2023-12-04  535  
a9f3450f06a026 Kamel Bouhara 2023-12-04  536  static int axiom_i2c_probe(struct i2c_client *client)
a9f3450f06a026 Kamel Bouhara 2023-12-04  537  {
a9f3450f06a026 Kamel Bouhara 2023-12-04  538  	struct device *dev = &client->dev;
a9f3450f06a026 Kamel Bouhara 2023-12-04  539  	struct input_dev *input_dev;
a9f3450f06a026 Kamel Bouhara 2023-12-04  540  	struct axiom_data *ts;
a9f3450f06a026 Kamel Bouhara 2023-12-04  541  	u32 startup_delay_ms;
a9f3450f06a026 Kamel Bouhara 2023-12-04  542  	u32 poll_interval;
a9f3450f06a026 Kamel Bouhara 2023-12-04  543  	int target;
a9f3450f06a026 Kamel Bouhara 2023-12-04  544  	int error;
a9f3450f06a026 Kamel Bouhara 2023-12-04  545  
a9f3450f06a026 Kamel Bouhara 2023-12-04  546  	ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
a9f3450f06a026 Kamel Bouhara 2023-12-04  547  	if (!ts)
a9f3450f06a026 Kamel Bouhara 2023-12-04  548  		return -ENOMEM;
a9f3450f06a026 Kamel Bouhara 2023-12-04  549  
a9f3450f06a026 Kamel Bouhara 2023-12-04  550  	ts->client = client;
a9f3450f06a026 Kamel Bouhara 2023-12-04  551  	i2c_set_clientdata(client, ts);
a9f3450f06a026 Kamel Bouhara 2023-12-04  552  	ts->dev = dev;
a9f3450f06a026 Kamel Bouhara 2023-12-04  553  
a9f3450f06a026 Kamel Bouhara 2023-12-04  554  	ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
a9f3450f06a026 Kamel Bouhara 2023-12-04  555  	if (IS_ERR(ts->reset_gpio))
a9f3450f06a026 Kamel Bouhara 2023-12-04  556  		return dev_err_probe(dev, PTR_ERR(ts->reset_gpio), "failed to get reset GPIO\n");
a9f3450f06a026 Kamel Bouhara 2023-12-04  557  
a9f3450f06a026 Kamel Bouhara 2023-12-04  558  	if (ts->reset_gpio)
a9f3450f06a026 Kamel Bouhara 2023-12-04  559  		axiom_reset(ts->reset_gpio);
a9f3450f06a026 Kamel Bouhara 2023-12-04  560  
a9f3450f06a026 Kamel Bouhara 2023-12-04  561  	ts->vddi = devm_regulator_get_optional(dev, "VDDI");
a9f3450f06a026 Kamel Bouhara 2023-12-04  562  	if (!IS_ERR(ts->vddi)) {
a9f3450f06a026 Kamel Bouhara 2023-12-04  563  		error = regulator_enable(ts->vddi);
a9f3450f06a026 Kamel Bouhara 2023-12-04  564  		if (error)
a9f3450f06a026 Kamel Bouhara 2023-12-04 @565  			return dev_err_probe(&client->dev, PTR_ERR(ts->vddi),
a9f3450f06a026 Kamel Bouhara 2023-12-04  566  					     "Failed to enable VDDI regulator\n");
a9f3450f06a026 Kamel Bouhara 2023-12-04  567  	}
a9f3450f06a026 Kamel Bouhara 2023-12-04  568  
a9f3450f06a026 Kamel Bouhara 2023-12-04  569  	ts->vdda = devm_regulator_get_optional(dev, "VDDA");
a9f3450f06a026 Kamel Bouhara 2023-12-04  570  	if (!IS_ERR(ts->vdda)) {
a9f3450f06a026 Kamel Bouhara 2023-12-04  571  		error = regulator_enable(ts->vdda);
a9f3450f06a026 Kamel Bouhara 2023-12-04  572  		if (error) {
a9f3450f06a026 Kamel Bouhara 2023-12-04  573  			dev_err(dev, "Failed to get VDDA regulator\n");
a9f3450f06a026 Kamel Bouhara 2023-12-04  574  			regulator_disable(ts->vddi);
a9f3450f06a026 Kamel Bouhara 2023-12-04  575  			return error;
a9f3450f06a026 Kamel Bouhara 2023-12-04  576  		}
a9f3450f06a026 Kamel Bouhara 2023-12-04  577  		if (!device_property_read_u32(dev, "startup-time-ms", &startup_delay_ms))
a9f3450f06a026 Kamel Bouhara 2023-12-04  578  			msleep(startup_delay_ms);
a9f3450f06a026 Kamel Bouhara 2023-12-04  579  	}
a9f3450f06a026 Kamel Bouhara 2023-12-04  580  
a9f3450f06a026 Kamel Bouhara 2023-12-04  581  	error = axiom_discover(ts);
a9f3450f06a026 Kamel Bouhara 2023-12-04  582  	if (error)
a9f3450f06a026 Kamel Bouhara 2023-12-04  583  		return dev_err_probe(dev, error, "Failed touchscreen discover\n");
a9f3450f06a026 Kamel Bouhara 2023-12-04  584  
a9f3450f06a026 Kamel Bouhara 2023-12-04  585  	input_dev = devm_input_allocate_device(ts->dev);
a9f3450f06a026 Kamel Bouhara 2023-12-04  586  	if (!input_dev)
a9f3450f06a026 Kamel Bouhara 2023-12-04  587  		return -ENOMEM;
a9f3450f06a026 Kamel Bouhara 2023-12-04  588  
a9f3450f06a026 Kamel Bouhara 2023-12-04  589  	input_dev->name = "TouchNetix axiom Touchscreen";
a9f3450f06a026 Kamel Bouhara 2023-12-04  590  	input_dev->phys = "input/axiom_ts";
a9f3450f06a026 Kamel Bouhara 2023-12-04  591  
a9f3450f06a026 Kamel Bouhara 2023-12-04  592  	/* Single Touch */
a9f3450f06a026 Kamel Bouhara 2023-12-04  593  	input_set_abs_params(input_dev, ABS_X, 0, 65535, 0, 0);
a9f3450f06a026 Kamel Bouhara 2023-12-04  594  	input_set_abs_params(input_dev, ABS_Y, 0, 65535, 0, 0);
a9f3450f06a026 Kamel Bouhara 2023-12-04  595  
a9f3450f06a026 Kamel Bouhara 2023-12-04  596  	/* Multi Touch */
a9f3450f06a026 Kamel Bouhara 2023-12-04  597  	/* Min, Max, Fuzz (expected noise in px, try 4?) and Flat */
a9f3450f06a026 Kamel Bouhara 2023-12-04  598  	input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0, 65535, 0, 0);
a9f3450f06a026 Kamel Bouhara 2023-12-04  599  	/* Min, Max, Fuzz (expected noise in px, try 4?) and Flat */
a9f3450f06a026 Kamel Bouhara 2023-12-04  600  	input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0, 65535, 0, 0);
a9f3450f06a026 Kamel Bouhara 2023-12-04  601  	input_set_abs_params(input_dev, ABS_MT_TOOL_TYPE, 0, MT_TOOL_MAX, 0, 0);
a9f3450f06a026 Kamel Bouhara 2023-12-04  602  	input_set_abs_params(input_dev, ABS_MT_DISTANCE, 0, 127, 0, 0);
a9f3450f06a026 Kamel Bouhara 2023-12-04  603  	input_set_abs_params(input_dev, ABS_MT_PRESSURE, 0, 127, 0, 0);
a9f3450f06a026 Kamel Bouhara 2023-12-04  604  
a9f3450f06a026 Kamel Bouhara 2023-12-04  605  	input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
a9f3450f06a026 Kamel Bouhara 2023-12-04  606  
a9f3450f06a026 Kamel Bouhara 2023-12-04  607  	/* Registers the axiom device as a touchscreen instead of a mouse pointer */
a9f3450f06a026 Kamel Bouhara 2023-12-04  608  	error = input_mt_init_slots(input_dev, AXIOM_U41_MAX_TARGETS, INPUT_MT_DIRECT);
a9f3450f06a026 Kamel Bouhara 2023-12-04  609  	if (error)
a9f3450f06a026 Kamel Bouhara 2023-12-04  610  		return error;
a9f3450f06a026 Kamel Bouhara 2023-12-04  611  
a9f3450f06a026 Kamel Bouhara 2023-12-04  612  	/* Enables the raw data for up to 4 force channels to be sent to the input subsystem */
a9f3450f06a026 Kamel Bouhara 2023-12-04  613  	set_bit(EV_REL, input_dev->evbit);
a9f3450f06a026 Kamel Bouhara 2023-12-04  614  	set_bit(EV_MSC, input_dev->evbit);
a9f3450f06a026 Kamel Bouhara 2023-12-04  615  	/* Declare that we support "RAW" Miscellaneous events */
a9f3450f06a026 Kamel Bouhara 2023-12-04  616  	set_bit(MSC_RAW, input_dev->mscbit);
a9f3450f06a026 Kamel Bouhara 2023-12-04  617  
a9f3450f06a026 Kamel Bouhara 2023-12-04  618  	ts->input_dev = input_dev;
a9f3450f06a026 Kamel Bouhara 2023-12-04  619  	input_set_drvdata(ts->input_dev, ts);
a9f3450f06a026 Kamel Bouhara 2023-12-04  620  
a9f3450f06a026 Kamel Bouhara 2023-12-04  621  	/* Ensure that all reports are initialised to not be present. */
a9f3450f06a026 Kamel Bouhara 2023-12-04  622  	for (target = 0; target < AXIOM_U41_MAX_TARGETS; target++)
a9f3450f06a026 Kamel Bouhara 2023-12-04  623  		ts->targets[target].state = AXIOM_TARGET_STATE_NOT_PRESENT;
a9f3450f06a026 Kamel Bouhara 2023-12-04  624  
a9f3450f06a026 Kamel Bouhara 2023-12-04  625  	error = input_register_device(input_dev);
a9f3450f06a026 Kamel Bouhara 2023-12-04  626  	if (error)
a9f3450f06a026 Kamel Bouhara 2023-12-04  627  		return dev_err_probe(ts->dev, error,
a9f3450f06a026 Kamel Bouhara 2023-12-04  628  				     "Could not register with Input Sub-system.\n");
a9f3450f06a026 Kamel Bouhara 2023-12-04  629  
a9f3450f06a026 Kamel Bouhara 2023-12-04  630  	error = devm_request_threaded_irq(dev, client->irq, NULL,
a9f3450f06a026 Kamel Bouhara 2023-12-04  631  					  axiom_irq, IRQF_ONESHOT, dev_name(dev), ts);
a9f3450f06a026 Kamel Bouhara 2023-12-04  632  	if (error < 0) {
a9f3450f06a026 Kamel Bouhara 2023-12-04  633  		dev_warn(dev, "Request irq failed, falling back to polling mode");
a9f3450f06a026 Kamel Bouhara 2023-12-04  634  
a9f3450f06a026 Kamel Bouhara 2023-12-04  635  		error = input_setup_polling(input_dev, axiom_i2c_poll);
a9f3450f06a026 Kamel Bouhara 2023-12-04  636  		if (error)
a9f3450f06a026 Kamel Bouhara 2023-12-04  637  			return dev_err_probe(ts->dev, error, "Unable to set up polling mode\n");
a9f3450f06a026 Kamel Bouhara 2023-12-04  638  
a9f3450f06a026 Kamel Bouhara 2023-12-04  639  		if (!device_property_read_u32(ts->dev, "poll-interval", &poll_interval))
a9f3450f06a026 Kamel Bouhara 2023-12-04  640  			input_set_poll_interval(input_dev, poll_interval);
a9f3450f06a026 Kamel Bouhara 2023-12-04  641  		else
a9f3450f06a026 Kamel Bouhara 2023-12-04  642  			input_set_poll_interval(input_dev, POLL_INTERVAL_DEFAULT_MS);
a9f3450f06a026 Kamel Bouhara 2023-12-04  643  	}
a9f3450f06a026 Kamel Bouhara 2023-12-04  644  
a9f3450f06a026 Kamel Bouhara 2023-12-04  645  	return 0;
a9f3450f06a026 Kamel Bouhara 2023-12-04  646  }
a9f3450f06a026 Kamel Bouhara 2023-12-04  647  

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