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Message-Id: <20231009134435.36311-4-kamel.bouhara@bootlin.com>
Date: Mon, 9 Oct 2023 15:44:35 +0200
From: Kamel Bouhara <kamel.bouhara@...tlin.com>
To: Dmitry Torokhov <dmitry.torokhov@...il.com>,
Rob Herring <robh+dt@...nel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
Conor Dooley <conor+dt@...nel.org>,
Henrik Rydberg <rydberg@...math.org>
Cc: linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
devicetree@...r.kernel.org, mark.satterthwaite@...chnetix.com,
pedro.torruella@...chnetix.com, bartp@...sheep.co.uk,
hannah.rossiter@...chnetix.com,
Thomas Petazzoni <thomas.petazzoni@...tlin.com>,
Gregory Clement <gregory.clement@...tlin.com>,
bsp-development.geo@...ca-geosystems.com,
Kamel Bouhara <kamel.bouhara@...tlin.com>
Subject: [PATCH v2 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 <kamel.bouhara@...tlin.com>
---
MAINTAINERS | 1 +
drivers/input/touchscreen/Kconfig | 13 +
drivers/input/touchscreen/Makefile | 1 +
.../input/touchscreen/touchnetix_axiom_i2c.c | 747 ++++++++++++++++++
4 files changed, 762 insertions(+)
create mode 100644 drivers/input/touchscreen/touchnetix_axiom_i2c.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 12ae8bc6b8cf..2d1e0b025e89 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -21415,6 +21415,7 @@ M: Kamel Bouhara <kamel.bouhara@...tlin.com>
L: linux-input@...r.kernel.org
S: Maintained
F: Documentation/devicetree/bindings/input/touchscreen/touchnetix,axiom-ax54a.yaml
+F: drivers/input/touchscreen/touchnetix_axiom_i2c.c
THUNDERBOLT DMA TRAFFIC TEST DRIVER
M: Isaac Hazan <isaac.hazan@...el.com>
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index e3e2324547b9..58665ccbe077 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -803,6 +803,19 @@ config TOUCHSCREEN_MIGOR
To compile this driver as a module, choose M here: the
module will be called migor_ts.
+config TOUCHSCREEN_TOUCHNETIX_AXIOM_I2C
+ tristate "TouchNetix AXIOM based touchscreen controllers"
+ depends on I2C
+ depends on GPIOLIB || COMPILE_TEST
+ 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_i2c.
+
config TOUCHSCREEN_TOUCHRIGHT
tristate "Touchright serial touchscreen"
select SERIO
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 62bd24f3ac8e..23b6fb8864b0 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-$(CONFIG_TOUCHSCREEN_TOUCHNETIX_AXIOM_I2C) += touchnetix_axiom_i2c.o
obj-$(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_i2c.c b/drivers/input/touchscreen/touchnetix_axiom_i2c.c
new file mode 100644
index 000000000000..d1683440ad91
--- /dev/null
+++ b/drivers/input/touchscreen/touchnetix_axiom_i2c.c
@@ -0,0 +1,747 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * TouchNetix aXiom Touchscreen Driver
+ *
+ * Copyright (C) 2020-2023 TouchNetix Ltd.
+ *
+ * Author(s): Bart Prescott <bartp@...sheep.co.uk>
+ * Pedro Torruella <pedro.torruella@...chnetix.com>
+ * Mark Satterthwaite <mark.satterthwaite@...chnetix.com>
+ * Hannah Rossiter <hannah.rossiter@...chnetix.com>
+ * Kamel Bouhara <kamel.bouhara@...tlin.com>
+ *
+ */
+
+#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>
+#include <linux/pm.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+/*
+ * Runtime TCP mode: device is executing normal code and is
+ * accessible via the Touch Controller Mode
+ */
+#define BOOT_TCP 0
+/*
+ * Bootloader BLP mode: device is executing bootloader and is
+ * accessible via the Boot Loader Protocol.
+ */
+#define BOOT_BLP 1
+#define AXIOM_PROX_LEVEL -128
+/*
+ * Register group u31 has 2 pages for usage table entries.
+ * (2 * AXIOM_COMMS_PAGE_SIZE) / AXIOM_U31_BYTES_PER_USAGE = 85
+ */
+#define AXIOM_U31_MAX_USAGES 85
+#define AXIOM_U31_BYTES_PER_USAGE 6
+#define AXIOM_U31_PAGE0_LENGTH 0x0C
+#define AXIOM_U31_BOOTMODE_MASK BIT(7)
+#define AXIOM_U31_FW_INFO_VARIANT_MASK GENMASK(6, 0)
+#define AXIOM_U31_FW_INFO_STATUS_MASK BIT(7)
+
+#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_OVERFLOW_MASK BIT(7)
+#define AXIOM_COMMS_REPORT_LEN_MASK GENMASK(7, 0)
+
+#define AXIOM_REBASELINE_CMD 0x03
+
+#define AXIOM_REPORT_USAGE_ID 0x34
+#define AXIOM_DEVINFO_USAGE_ID 0x31
+#define AXIOM_USAGE_2HB_REPORT_ID 0x01
+#define AXIOM_REBASELINE_USAGE_ID 0x02
+#define AXIOM_USAGE_2AUX_REPORT_ID 0x46
+#define AXIOM_USAGE_2DCTS_REPORT_ID 0x41
+
+#define AXIOM_PAGE_MASK GENMASK(15, 8)
+#define AXIOM_PAGE_OFFSET_MASK GENMASK(7, 0)
+
+struct axiom_devinfo {
+ char bootloader_fw_major;
+ char bootloader_fw_minor;
+ char bootmode;
+ u16 device_id;
+ char fw_major;
+ char fw_minor;
+ char fw_info_extra;
+ char tcp_revision;
+ u16 jedec_id;
+ char num_usages;
+ char silicon_revision;
+};
+
+/*
+ * Describes parameters of a specific usage, essenstially a single element of
+ * the "Usage Table"
+ */
+struct usage_entry {
+ char id;
+ char is_report;
+ char start_page;
+ char num_pages;
+};
+
+/*
+ * Holds state of a touch or target when detected prior a touch (eg.
+ * hover or proximity events).
+ */
+enum axiom_target_state {
+ TARGET_STATE_NOT_PRESENT = 0,
+ TARGET_STATE_PROX = 1,
+ TARGET_STATE_HOVER = 2,
+ TARGET_STATE_TOUCHING = 3,
+ TARGET_STATE_MIN = TARGET_STATE_NOT_PRESENT,
+ TARGET_STATE_MAX = TARGET_STATE_TOUCHING,
+};
+
+struct 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 {
+ u16 target_address;
+ u16 length:15;
+ u16 read:1;
+};
+
+struct axiom_data {
+ struct axiom_devinfo devinfo;
+ struct device *dev;
+ struct gpio_desc *reset_gpio;
+ struct gpio_desc *irq_gpio;
+ struct i2c_client *client;
+ struct input_dev *input_dev;
+ u32 max_report_len;
+ u32 report_overflow_counter;
+ u32 report_counter;
+ char rx_buf[AXIOM_COMMS_MAX_USAGE_PAGES * AXIOM_COMMS_PAGE_SIZE];
+ struct u41_target targets[AXIOM_U41_MAX_TARGETS];
+ struct usage_entry usage_table[AXIOM_U31_MAX_USAGES];
+ bool usage_table_populated;
+};
+
+/*
+ * aXiom devices are typically configured to report
+ * touches at a rate of 100Hz (10ms). For systems
+ * that require polling for reports, 100ms seems like
+ * an acceptable polling rate.
+ * 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 100
+
+/**
+ * Translate usage/page/offset triplet into physical address.
+ *
+ * @usage: groups of registers
+ * @page: page to which the usage belongs to offset
+ * @offset: offset of the usage
+ * @return: target address on success, 0xFFFF on error
+ */
+static u16
+usage_to_target_address(struct axiom_data *ts, char usage, char page,
+ char offset)
+{
+ struct axiom_devinfo *device_info;
+ struct usage_entry *usage_table;
+ 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 < device_info->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;
+ }
+ }
+
+ 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;
+ struct i2c_msg msg[2];
+ int ret;
+
+ cmd_header.target_address = cpu_to_le16(usage_to_target_address(ts, usage, page, 0));
+ cmd_header.length = cpu_to_le16(len);
+ cmd_header.read = cpu_to_le16(1);
+
+ 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;
+
+ ret = i2c_transfer(client->adapter, msg, 2);
+ if (ret != ARRAY_SIZE(msg)) {
+ dev_err(&client->dev,
+ "Failed reading usage %#x page %#x, error=%d\n",
+ usage, page, ret);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static int
+axiom_i2c_write(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 ret;
+
+ cmd_header.target_address = cpu_to_le16(usage_to_target_address(ts, usage, page, 0));
+ cmd_header.length = cpu_to_le16(len);
+ cmd_header.read = 0;
+
+ 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 = 0;
+ msg[1].len = len;
+ msg[1].buf = (char *)buf;
+
+ ret = i2c_transfer(client->adapter, msg, 2);
+ if (ret < 0) {
+ dev_err(&client->dev,
+ "Failed to write usage %#x page %#x, error=%d\n", usage,
+ page, ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+/*
+ * Decodes and populates the local Usage Table.
+ * Given a buffer of data read from page 1 onwards of u31 from an aXiom
+ * device.
+ */
+static u32 axiom_populate_usage_table(struct axiom_data *ts, char *rx_data)
+{
+ u32 usage_id = 0;
+ u32 max_report_len = 0;
+ struct axiom_devinfo *device_info;
+ struct usage_entry *usage_table;
+
+ device_info = &ts->devinfo;
+ usage_table = ts->usage_table;
+
+ for (usage_id = 0; usage_id < device_info->num_usages; usage_id++) {
+ u16 offset = (usage_id * AXIOM_U31_BYTES_PER_USAGE);
+ char id = rx_data[offset + 0];
+ char start_page = rx_data[offset + 1];
+ char 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 %2u Info: %*ph\n", usage_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;
+}
+
+/* Retrieve, store and print the axiom device information */
+static int axiom_discover(struct axiom_data *ts)
+{
+ struct axiom_devinfo *devinfo = &ts->devinfo;
+ struct device *dev = ts->dev;
+ char *rx_data = ts->rx_buf;
+ int ret;
+
+ /*
+ * Fetch the first page of usage u31 to get the
+ * device information and the number of usages
+ */
+ ret = axiom_i2c_read(ts->client, AXIOM_DEVINFO_USAGE_ID, 0, rx_data,
+ AXIOM_U31_PAGE0_LENGTH);
+ if (ret)
+ return ret;
+
+ devinfo->bootmode = (rx_data[0] & AXIOM_U31_BOOTMODE_MASK);
+ devinfo->device_id = ((rx_data[1] & AXIOM_PAGE_OFFSET_MASK) << 8) | rx_data[0];
+ devinfo->fw_minor = rx_data[2];
+ devinfo->fw_major = rx_data[3];
+ devinfo->fw_info_extra = rx_data[4];
+ devinfo->bootloader_fw_minor = rx_data[6];
+ devinfo->bootloader_fw_major = rx_data[7];
+ devinfo->jedec_id = (rx_data[8]) | (rx_data[9] << 8);
+ devinfo->num_usages = rx_data[10];
+ devinfo->silicon_revision = rx_data[11];
+
+ dev_dbg(dev, " Boot Mode: %s\n", ts->devinfo.bootmode ? "BLP" : "TCP");
+ dev_dbg(dev, " Device ID : %04x\n", ts->devinfo.device_id);
+ dev_dbg(dev, " Firmware Rev : %02x.%02x\n", ts->devinfo.fw_major,
+ ts->devinfo.fw_minor);
+ dev_dbg(dev, " Bootloader Rev : %02x.%02x\n",
+ ts->devinfo.bootloader_fw_major,
+ ts->devinfo.bootloader_fw_minor);
+ dev_dbg(dev, " FW Extra Info : %04x\n", ts->devinfo.fw_info_extra);
+ dev_dbg(dev, " Silicon : %02x\n", ts->devinfo.jedec_id);
+ dev_dbg(dev, " Num Usages : %04x\n", ts->devinfo.num_usages);
+
+ /* Read the second page of usage u31 to get the usage table */
+ ret = axiom_i2c_read(ts->client, AXIOM_DEVINFO_USAGE_ID, 1, rx_data,
+ (AXIOM_U31_BYTES_PER_USAGE * ts->devinfo.num_usages));
+ if (ret)
+ return ret;
+
+ ts->max_report_len = axiom_populate_usage_table(ts, rx_data);
+ dev_dbg(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;
+ enum axiom_target_state current_state;
+ struct u41_target *target_prev_state;
+ struct device *dev = ts->dev;
+ bool update = false;
+ int slot;
+
+ /* Verify the target index */
+ if (target->index >= AXIOM_U41_MAX_TARGETS) {
+ dev_dbg(dev, "Invalid target index! %u\n", target->index);
+ return false;
+ }
+
+ target_prev_state = &ts->targets[target->index];
+
+ current_state = TARGET_STATE_NOT_PRESENT;
+
+ if (target->present) {
+ if (target->z >= 0)
+ current_state = TARGET_STATE_TOUCHING;
+ else if (target->z > AXIOM_PROX_LEVEL && target->z < 0)
+ current_state = TARGET_STATE_HOVER;
+ else if (target->z AXIOM_PROX_LEVEL)
+ current_state = 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(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 TARGET_STATE_NOT_PRESENT:
+ case 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_LEFT, 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 TARGET_STATE_HOVER:
+ case 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 == 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_LEFT, (current_state ==
+ TARGET_STATE_TOUCHING));
+ 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;
+
+ if (update)
+ input_mt_sync_frame(input_dev);
+
+ return update;
+}
+
+/*
+ * Take a raw buffer with u41 report data and decode it.
+ * Also generate input events if needed.
+ * rx_buf: ptr to a byte array [0]: Usage number [1]: Status LSB [2]: Status MSB
+ */
+static void axiom_process_u41_report(struct axiom_data *ts, char *rx_buf)
+{
+ struct input_dev *input_dev = ts->input_dev;
+ 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 = rx_buf[(i * 4)];
+
+ target.index = i;
+ target.present = ((target_status & (1 << i)) != 0) ? 1 : 0;
+ target.x = ((target_step + 3) | ((target_step + 4) << 8));
+ target.y = ((target_step + 5) | ((target_step + 6) << 8));
+ target.z = (s8)(rx_buf[i + 43]);
+ update_done |= axiom_process_u41_report_target(ts, &target);
+ }
+
+ if (update_done)
+ input_sync(input_dev);
+}
+
+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 = rx_buf[(i * 2)];
+
+ aux_value = (((target_step + 2) << 8) | (target_step + 1)) & AXIOM_U46_AUX_MASK;
+ event_value = (i << 16) | (aux_value);
+ input_event(input_dev, EV_MSC, MSC_RAW, event_value);
+ }
+
+ input_mt_sync(input_dev);
+ input_sync(input_dev);
+}
+
+/*
+ * Validates the crc and demultiplexes the axiom reports to the appropriate
+ * report handler
+ */
+void axiom_handle_events(struct axiom_data *ts)
+{
+ char *report_data = ts->rx_buf;
+ struct device *dev = ts->dev;
+ char usage = report_data[1];
+ u16 crc_report;
+ u16 crc_calc;
+ char len;
+
+ axiom_i2c_read(ts->client, AXIOM_REPORT_USAGE_ID, 0, report_data, ts->max_report_len);
+
+ if ((report_data[0] & AXIOM_COMMS_OVERFLOW_MASK) != 0)
+ ts->report_overflow_counter++;
+
+ len = (report_data[0] & AXIOM_COMMS_REPORT_LEN_MASK) * 2;
+ if (!len) {
+ dev_err(dev, "Zero length report discarded.\n");
+ return;
+ }
+
+ dev_dbg(dev, "Payload Data %*ph\n", len, report_data);
+
+ /* 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;
+ }
+
+ switch (usage) {
+ case AXIOM_USAGE_2DCTS_REPORT_ID:
+ axiom_process_u41_report(ts, &report_data[1]);
+ break;
+
+ case AXIOM_USAGE_2AUX_REPORT_ID:
+ /* This is an aux report (force) */
+ axiom_process_u46_report(ts, &report_data[1]);
+ break;
+
+ case AXIOM_USAGE_2HB_REPORT_ID:
+ /* This is a heartbeat report */
+ break;
+ }
+
+ ts->report_counter++;
+}
+
+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(100);
+}
+
+/* Rebaseline the touchscreen, effectively zero-ing it */
+static int axiom_rebaseline(struct axiom_data *ts)
+{
+ char buffer[8] = {};
+
+ buffer[0] = AXIOM_REBASELINE_CMD;
+
+ return axiom_i2c_write(ts->client, AXIOM_REPORT_USAGE_ID, 0, buffer, sizeof(buffer));
+}
+
+static int axiom_i2c_probe(struct i2c_client *client)
+{
+ struct device *dev = &client->dev;
+ struct input_dev *input_dev;
+ struct axiom_data *ts;
+ int ret;
+ int target;
+
+ ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
+ if (!ts)
+ return -ENOMEM;
+
+ ts->client = client;
+ i2c_set_clientdata(client, ts);
+ ts->dev = dev;
+
+ ts->irq_gpio = devm_gpiod_get_optional(dev, "irq", GPIOD_IN);
+ if (IS_ERR(ts->irq_gpio))
+ return dev_err_probe(dev, PTR_ERR(ts->irq_gpio), "failed to get irq GPIO");
+
+ 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");
+
+ axiom_reset(ts->reset_gpio);
+
+ if (ts->irq_gpio) {
+ ret = devm_request_threaded_irq(dev, client->irq, NULL,
+ axiom_irq, 0, dev_name(dev), ts);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Failed to request threaded IRQ\n");
+ }
+
+ ret = axiom_discover(ts);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed touchscreen discover\n");
+
+ ret = axiom_rebaseline(ts);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed touchscreen re-baselining\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);
+
+ /* Registers the axiom device as a touchscreen instead of as a mouse pointer */
+ input_mt_init_slots(input_dev, AXIOM_U41_MAX_TARGETS, INPUT_MT_DIRECT);
+
+ input_set_capability(input_dev, EV_KEY, BTN_LEFT);
+
+ /* 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);
+
+ if (!ts->irq_gpio) {
+ ret = input_setup_polling(input_dev, axiom_i2c_poll);
+ if (ret)
+ return dev_err_probe(ts->dev, ret, "Unable to set up polling mode\n");
+ input_set_poll_interval(input_dev, POLL_INTERVAL_DEFAULT_MS);
+ }
+
+ 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 = TARGET_STATE_NOT_PRESENT;
+
+ ret = input_register_device(input_dev);
+
+ if (ret)
+ return dev_err_probe(ts->dev, ret,
+ "Could not register with Input Sub-system.\n");
+
+ return 0;
+}
+
+static void axiom_i2c_remove(struct i2c_client *client)
+{
+ struct axiom_data *ts = i2c_get_clientdata(client);
+
+ input_unregister_device(ts->input_dev);
+}
+
+static const struct i2c_device_id axiom_i2c_id_table[] = {
+ { "axiom-ax54a" },
+ {},
+};
+
+MODULE_DEVICE_TABLE(i2c, axiom_i2c_id_table);
+
+static const struct of_device_id axiom_i2c_of_match[] = {
+ { .compatible = "touchnetix,axiom-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,
+ .remove = axiom_i2c_remove,
+};
+
+module_i2c_driver(axiom_i2c_driver);
+
+MODULE_AUTHOR("Bart Prescott <bartp@...sheep.co.uk>");
+MODULE_AUTHOR("Pedro Torruella <pedro.torruella@...chnetix.com>");
+MODULE_AUTHOR("Mark Satterthwaite <mark.satterthwaite@...chnetix.com>");
+MODULE_AUTHOR("Hannah Rossiter <hannah.rossiter@...chnetix.com>");
+MODULE_AUTHOR("Kamel Bouhara <kamel.bouhara@...tlin.com>");
+MODULE_DESCRIPTION("TouchNetix aXiom touchscreen I2C bus driver");
+MODULE_LICENSE("GPL");
--
2.25.1
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