LinuxLists.cc - [PATCH v5 0/3] Input: Add TouchNetix axiom touchscreen driver

2023-12-11 12:15:07

Subject: [PATCH v5 0/3] Input: Add TouchNetix axiom touchscreen driver

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/[email protected]/

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

Changes in v5:
- Fix wrong message constructed in axiom_i2c_read
- Delay required between i2c reads is >= 250us
- Do not split report reading in two phases as we'll
have to wait 500us
- Use lower-case in properties names
- Make regulators properties are required in dt-binding
- Fix bug report: https://lore.kernel.org/lkml/[email protected]/
- Fix bug report: https://lore.kernel.org/lkml/[email protected]/

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 | 64 ++
.../devicetree/bindings/vendor-prefixes.yaml | 2 +
MAINTAINERS | 7 +
drivers/input/touchscreen/Kconfig | 12 +
drivers/input/touchscreen/Makefile | 1 +
drivers/input/touchscreen/touchnetix_axiom.c | 667 ++++++++++++++++++
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

2023-12-11 12:15:24

by Kamel Bouhara

[permalink] [raw]

Subject: [PATCH v5 2/3] dt-bindings: input: Add TouchNetix axiom touchscreen

Add the TouchNetix axiom I2C touchscreen device tree bindings
documentation.

Signed-off-by: Kamel Bouhara <[email protected]>
---
.../input/touchscreen/touchnetix,ax54a.yaml | 64 +++++++++++++++++++
MAINTAINERS | 6 ++
2 files changed, 70 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..cbdf48fc538b
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/touchnetix,ax54a.yaml
@@ -0,0 +1,64 @@
+# 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 <[email protected]>
+
+allOf:
+ - $ref: /schemas/input/touchscreen/touchscreen.yaml#
+ - $ref: /schemas/input/input.yaml#
+
+properties:
+ compatible:
+ const: touchnetix,ax54a
+
+ reg:
+ const: 0x66
+
+ interrupts:
+ maxItems: 1
+
+ reset-gpios:
+ maxItems: 1
+
+ vdda-supply:
+ description: Analog power supply regulator on VDDA pin
+
+ vddi-supply:
+ description: I/O power supply regulator on VDDI pin
+
+ poll-interval: true
+
+required:
+ - compatible
+ - reg
+ - vdda-supply
+ - vddi-supply
+
+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>;
+ vdda-supply = <&vdda_reg>;
+ vddi-supply = <&vddi_reg>;
+ poll-interval = <20>;
+ };
+ };
+...
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 <[email protected]>
+L: [email protected]
+S: Maintained
+F: Documentation/devicetree/bindings/input/touchscreen/touchnetix,ax54a.yaml
+
THUNDERBOLT DMA TRAFFIC TEST DRIVER
M: Isaac Hazan <[email protected]>
L: [email protected]
--
2.25.1

2023-12-11 12:15:54

by Kamel Bouhara

[permalink] [raw]

Subject: [PATCH v5 1/3] dt-bindings: vendor-prefixes: Add TouchNetix AS

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

Signed-off-by: Kamel Bouhara <[email protected]>
Acked-by: Krzysztof Kozlowski <[email protected]>
---
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

2023-12-11 12:15:57

by Kamel Bouhara

[permalink] [raw]

Subject: [PATCH v5 3/3] Input: Add TouchNetix axiom i2c touchscreen driver

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 <[email protected]>
---
MAINTAINERS | 1 +
drivers/input/touchscreen/Kconfig | 12 +
drivers/input/touchscreen/Makefile | 1 +
drivers/input/touchscreen/touchnetix_axiom.c | 667 +++++++++++++++++++
4 files changed, 681 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 <[email protected]>
L: [email protected]
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 <[email protected]>
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..4ade2d1adba0
--- /dev/null
+++ b/drivers/input/touchscreen/touchnetix_axiom.c
@@ -0,0 +1,667 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * TouchNetix axiom Touchscreen Driver
+ *
+ * Copyright (C) 2020-2023 TouchNetix Ltd.
+ *
+ * Author(s): Bart Prescott <[email protected]>
+ * Pedro Torruella <[email protected]>
+ * Mark Satterthwaite <[email protected]>
+ * Hannah Rossiter <[email protected]>
+ * Kamel Bouhara <[email protected]>
+ *
+ */
+#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)
+{
+ u32 i;
+
+ /* 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 (ts->usage_table[i].id != usage)
+ continue;
+
+ if (page >= ts->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 ((ts->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;
+ struct i2c_msg msg[2];
+ 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);
+
+ msg[0].addr = client->addr;
+ msg[0].flags = 0;
+ msg[0].len = sizeof(cmd_header);
+ msg[0].buf = (u8 *)&cmd_header;
+
+ msg[1].addr = client->addr;
+ msg[1].flags = I2C_M_RD;
+ msg[1].len = len;
+ msg[1].buf = (char *)buf;
+
+ error = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
+ if (error != ARRAY_SIZE(msg)) {
+ dev_err(&client->dev,
+ "Failed reading usage %#x page %#x, error=%d\n",
+ usage, page, error);
+ return -EIO;
+ }
+
+ usleep_range(250, 300);
+
+ return 0;
+}
+
+/*
+ * One of the main purposes for reading the usage table is to identify
+ * which usages reside at which target address.
+ * When performing subsequent reads or writes to AXIOM, the target address
+ * 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;
+ struct device *dev = ts->dev;
+ u16 crc_report;
+ u16 crc_calc;
+ int error;
+ char len;
+
+ error = axiom_i2c_read(ts->client, AXIOM_REPORT_USAGE_ID, 0, report_data,
+ ts->max_report_len);
+ if (error)
+ return error;
+
+ len = (report_data[0] & AXIOM_COMMS_REPORT_LEN_MASK) << 1;
+ if (!len) {
+ dev_err(dev, "Zero length report discarded.\n");
+ return -ENODATA;
+ }
+
+ /* Validate the report CRC */
+ crc_report = (report_data[len - 1] << 8) | (report_data[len - 2]);
+ /* Length is in 16 bit words and remove the size of the CRC16 itself */
+ crc_calc = crc16(0, report_data, (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, error,
+ "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 <[email protected]>");
+MODULE_AUTHOR("Pedro Torruella <[email protected]>");
+MODULE_AUTHOR("Mark Satterthwaite <[email protected]>");
+MODULE_AUTHOR("Hannah Rossiter <[email protected]>");
+MODULE_AUTHOR("Kamel Bouhara <[email protected]>");
+MODULE_DESCRIPTION("TouchNetix axiom touchscreen I2C bus driver");
+MODULE_LICENSE("GPL");
--
2.25.1

2023-12-12 16:57:45

On Wed, Jan 31, 2024 at 06:14:41PM +0100, Kamel Bouhara wrote:
> On Thu, Dec 28, 2023 at 09:44:31PM -0600, Jeff LaBundy wrote:

[...]

> > > + 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);
> >
> > You do not need to explicitly report ABS_X and ABS_Y values, as calling
> > input_mt_sync_frame() effectively takes care of this by way of pointer
> > emulation.
> >
>
> After double checking/testing this, it doesn't seems to
> report ABS_X/Y values anymore, are you sure about this ? Maybe I missed
> some extra flag in input_mt_init_slots() for that ?

You are missing call to input_report_slot_state() before you start
sending position data. You also should not conflate tracking ID and
slot number. I.e. if you touch and release and touch again, you
likely report through the same slot 0, but the tracking ID of the
contact should be different.

Thanks.

--
Dmitry

2024-02-01 05:09:42

by Kamel Bouhara

[permalink] [raw]

Subject: Re: [PATCH v5 3/3] Input: Add TouchNetix axiom i2c touchscreen driver

On Wed, Jan 31, 2024 at 11:57:43AM -0800, Dmitry Torokhov wrote:
> On Wed, Jan 31, 2024 at 06:14:41PM +0100, Kamel Bouhara wrote:
> > On Thu, Dec 28, 2023 at 09:44:31PM -0600, Jeff LaBundy wrote:
>
> [...]
>
> > > > + 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);
> > >
> > > You do not need to explicitly report ABS_X and ABS_Y values, as calling
> > > input_mt_sync_frame() effectively takes care of this by way of pointer
> > > emulation.
> > >
> >
> > After double checking/testing this, it doesn't seems to
> > report ABS_X/Y values anymore, are you sure about this ? Maybe I missed
> > some extra flag in input_mt_init_slots() for that ?
>
> You are missing call to input_report_slot_state() before you start
> sending position data. You also should not conflate tracking ID and
> slot number. I.e. if you touch and release and touch again, you
> likely report through the same slot 0, but the tracking ID of the
> contact should be different.
>

Hi Dmitry,

Ok thanks for the clarification, I will check again but I think you are
right and target->index should be used as the tracking ID as it should
be different between reports.

This should be fixed in v8.

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