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Message-ID: <76a14af9-dc51-4d87-9110-a8be05702b56@leica-geosystems.com>
Date: Mon, 4 Dec 2023 15:09:58 +0000
From: POPESCU Catalin <catalin.popescu@...ca-geosystems.com>
To: Kamel Bouhara <kamel.bouhara@...tlin.com>,
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>,
"linux-input@...r.kernel.org" <linux-input@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
Marco Felsch <m.felsch@...gutronix.de>,
Jeff LaBundy <jeff@...undy.com>
CC: "mark.satterthwaite@...chnetix.com"
<mark.satterthwaite@...chnetix.com>,
"bartp@...sheep.co.uk" <bartp@...sheep.co.uk>,
"hannah.rossiter@...chnetix.com" <hannah.rossiter@...chnetix.com>,
Thomas Petazzoni <thomas.petazzoni@...tlin.com>,
Gregory Clement <gregory.clement@...tlin.com>,
GEO-CHHER-bsp-development
<bsp-development.geo@...ca-geosystems.com>
Subject: Re: [PATCH v4 3/3] Input: Add TouchNetix axiom i2c touchscreen driver
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@...tlin.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@...tlin.com>
> L: linux-input@...r.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@...el.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@...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/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@...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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