Re: [PATCH] input/touchscreen: synaptics_tcm_oncell: add driver
From: friederhannenheim
Date: Wed Mar 27 2024 - 18:19:29 EST
Looks like I forgot the most important thing: What is this actually used for. The Synaptics TCM Oncell Touchscreen is built into multiple smartphones: The OnePlus 8T (my device), Realme GT2 Pro, OnePlus 9 Pro, and more. I'm currently trying to get the OnePlus 8T working on mainline Linux that's why I wrote this driver.
On 2024-03-27 22:39, Frieder Hannenheim wrote:
> This is a bit of a stripped down and partially reworked driver for the
> synaptics_tcm_oncell touchscreen. I based my work off the driver in the
> LineageOS kernel found at
> https://github.com/LineageOS/android_kernel_oneplus_sm8250 branch
> lineage-20. The code was originally written by OnePlus developers but
> I'm not sure how to credit them correctly.
>
> Currently the driver is in a pretty good shape, the only thing that is
> not working is setting a report config. To me it looks like some data is
> sent by the touchscreen firmware after setting the report config that is
> making the irq handler crash. Sadly I haven't been able to test out why.
> The driver works fine also with the default touch report config so maybe
> we can just use that and not set our own.
>
> Signed-off-by: Frieder Hannenheim <friederhannenheim@xxxxxxxxxx>
> ---
> .../input/touchscreen/syna,s3908.yaml | 63 +
> drivers/input/touchscreen/Kconfig | 11 +
> drivers/input/touchscreen/Makefile | 1 +
> .../input/touchscreen/synaptics_tcm_oncell.c | 1104 +++++++++++++++++
> 4 files changed, 1179 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/input/touchscreen/syna,s3908.yaml
> create mode 100644 drivers/input/touchscreen/synaptics_tcm_oncell.c
>
> diff --git a/Documentation/devicetree/bindings/input/touchscreen/syna,s3908.yaml b/Documentation/devicetree/bindings/input/touchscreen/syna,s3908.yaml
> new file mode 100644
> index 000000000000..1a85747e2f52
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/touchscreen/syna,s3908.yaml
> @@ -0,0 +1,63 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/input/touchscreen/synaptics,s3908.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Synaptics s3908 touchscreen controller
> +
> +maintainers:
> + - Frieder Hannenheim <frieder.hannenheim@xxxxxxxxxx>
> +
> +allOf:
> + - $ref: touchscreen.yaml#
> +
> +properties:
> + compatible:
> + const: syna,s3908
> +
> + reg:
> + maxItems: 1
> +
> + interrupts:
> + maxItems: 1
> +
> + reset-gpios:
> + maxItems: 1
> + description: reset gpio the chip is connected to.
> +
> + vdd-supply: true
> + vcc-supply: true
> +
> + max-objects: true
> +
> +unevaluatedProperties: false
> +
> +required:
> + - compatible
> + - reg
> + - interrupts
> + - reset-gpios
> + - vdd-supply
> + - vcc-supply
> + - max-objects
> +
> +examples:
> + - |
> + #include <dt-bindings/interrupt-controller/irq.h>
> + i2c {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + touchscreen@48 {
> + compatible = "syna,s3908";
> + reg = <0x48>;
> + interrupt-parent = <&gpa1>;
> + interrupts = <1 IRQ_TYPE_LEVEL_HIGH>;
> + reset-gpios = <38 0>;
> + vdd-supply = <&ldo30_reg>;
> + vcc-supply = <&ldo31_reg>;
> +
> + max-objects = <10>;
> + };
> + };
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index 1f8b33c2b03d..eba31ae27391 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -502,6 +502,17 @@ config TOUCHSCREEN_S6SY761
>
> To compile this driver as module, choose M here: the
> module will be called s6sy761.
> +
> +config TOUCHSCREEN_SYNA_TCM_ONCELL
> + tristate "Synaptics TCM Oncell Touchscreen driver"
> + depends on I2C
> + help
> + Say Y if you have the Synaptics TCM Oncell driver
> +
> + If unsure, say N
> +
> + To compile this driver as module, choose M here: the
> + module will be called synaptics_tcm_oncell.
>
> config TOUCHSCREEN_GUNZE
> tristate "Gunze AHL-51S touchscreen"
> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
> index 7d52592f4290..f5395ccf09d5 100644
> --- a/drivers/input/touchscreen/Makefile
> +++ b/drivers/input/touchscreen/Makefile
> @@ -86,6 +86,7 @@ obj-$(CONFIG_TOUCHSCREEN_STMPE) += stmpe-ts.o
> obj-$(CONFIG_TOUCHSCREEN_SUN4I) += sun4i-ts.o
> obj-$(CONFIG_TOUCHSCREEN_SUR40) += sur40.o
> obj-$(CONFIG_TOUCHSCREEN_SURFACE3_SPI) += surface3_spi.o
> +obj-$(CONFIG_TOUCHSCREEN_SYNA_TCM_ONCELL) += synaptics_tcm_oncell.o
> obj-$(CONFIG_TOUCHSCREEN_TI_AM335X_TSC) += ti_am335x_tsc.o
> obj-$(CONFIG_TOUCHSCREEN_TOUCHIT213) += touchit213.o
> obj-$(CONFIG_TOUCHSCREEN_TOUCHRIGHT) += touchright.o
> diff --git a/drivers/input/touchscreen/synaptics_tcm_oncell.c b/drivers/input/touchscreen/synaptics_tcm_oncell.c
> new file mode 100644
> index 000000000000..b874287f37af
> --- /dev/null
> +++ b/drivers/input/touchscreen/synaptics_tcm_oncell.c
> @@ -0,0 +1,1104 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Driver for Synaptics TCM Oncell Touchscreens
> + *
> + * Copyright (c) 2024 Frieder Hannenheim <friederhannenheim@xxxxxxxxxx>
> + */
> +
> +#include <linux/i2c.h>
> +#include <linux/input.h>
> +#include <linux/input/touchscreen.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/property.h>
> +#include <asm/unaligned.h>
> +#include <linux/delay.h>
> +#include <linux/input/mt.h>
> +#include <linux/input/touchscreen.h>
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> +#include <linux/of_gpio.h>
> +#include <linux/module.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regulator/consumer.h>
> +
> +/* Meta Information */
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Frieder Hannenheim");
> +MODULE_DESCRIPTION("A driver for Synaptics TCM Oncell Touchpanels");
> +
> +#define TOUCHPANEL_DEVICE "syna-tcm"
> +
> +#define POWERUP_TO_RESET_TIME 10
> +#define RESET_TO_NORMAL_TIME 80
> +
> +#define RESPONSE_TIMEOUT_MS 1000
> +
> +#define MESSAGE_HEADER_SIZE 4
> +#define MESSAGE_MARKER 0xA5
> +#define MESSAGE_PADDING 0x5A
> +
> +#define READ_LENGTH 9
> +#define MAX_I2C_RETRY_TIME 4
> +
> +#define RD_CHUNK_SIZE 0 /* read length limit in bytes, 0 = unlimited */
> +#define WR_CHUNK_SIZE 0 /* write length limit in bytes, 0 = unlimited */
> +
> +#define APP_STATUS_POLL_MS 100
> +#define TOUCH_REPORT_CONFIG_SIZE 128
> +
> +enum command {
> + CMD_NONE = 0x00,
> + CMD_CONTINUE_WRITE = 0x01,
> + CMD_IDENTIFY = 0x02,
> + CMD_RESET = 0x04,
> + CMD_ENABLE_REPORT = 0x05,
> + CMD_DISABLE_REPORT = 0x06,
> + CMD_GET_BOOT_INFO = 0x10,
> + CMD_ERASE_FLASH = 0x11,
> + CMD_WRITE_FLASH = 0x12,
> + CMD_READ_FLASH = 0x13,
> + CMD_RUN_APPLICATION_FIRMWARE = 0x14,
> + CMD_SPI_MASTER_WRITE_THEN_READ = 0x15,
> + CMD_REBOOT_TO_ROM_BOOTLOADER = 0x16,
> + CMD_RUN_BOOTLOADER_FIRMWARE = 0x1f,
> + CMD_GET_APPLICATION_INFO = 0x20,
> + CMD_GET_STATIC_CONFIG = 0x21,
> + CMD_SET_STATIC_CONFIG = 0x22,
> + CMD_GET_DYNAMIC_CONFIG = 0x23,
> + CMD_SET_DYNAMIC_CONFIG = 0x24,
> + CMD_GET_TOUCH_REPORT_CONFIG = 0x25,
> + CMD_SET_TOUCH_REPORT_CONFIG = 0x26,
> + CMD_REZERO = 0x27,
> + CMD_COMMIT_CONFIG = 0x28,
> + CMD_DESCRIBE_DYNAMIC_CONFIG = 0x29,
> + CMD_PRODUCTION_TEST = 0x2a,
> + CMD_SET_CONFIG_ID = 0x2b,
> + CMD_ENTER_DEEP_SLEEP = 0x2c,
> + CMD_EXIT_DEEP_SLEEP = 0x2d,
> + CMD_GET_TOUCH_INFO = 0x2e,
> + CMD_GET_DATA_LOCATION = 0x2f,
> + CMD_DOWNLOAD_CONFIG = 0xc0,
> + CMD_GET_NSM_INFO = 0xc3,
> + CMD_EXIT_ESD = 0xc4,
> +};
> +
> +enum touch_report_code {
> + TOUCH_END = 0,
> + TOUCH_FOREACH_ACTIVE_OBJECT = 1,
> + TOUCH_FOREACH_OBJECT = 2,
> + TOUCH_FOREACH_END = 3,
> + TOUCH_PAD_TO_NEXT_BYTE = 4,
> + TOUCH_TIMESTAMP = 5,
> + TOUCH_OBJECT_N_INDEX = 6,
> + TOUCH_OBJECT_N_CLASSIFICATION = 7,
> + TOUCH_OBJECT_N_X_POSITION = 8,
> + TOUCH_OBJECT_N_Y_POSITION = 9,
> + TOUCH_OBJECT_N_Z = 10,
> + TOUCH_OBJECT_N_X_WIDTH = 11,
> + TOUCH_OBJECT_N_Y_WIDTH = 12,
> + TOUCH_OBJECT_N_TX_POSITION_TIXELS = 13,
> + TOUCH_OBJECT_N_RX_POSITION_TIXELS = 14,
> + TOUCH_0D_BUTTONS_STATE = 15,
> + TOUCH_GESTURE_DOUBLE_TAP = 16,
> + TOUCH_FRAME_RATE = 17,
> + TOUCH_POWER_IM = 18,
> + TOUCH_CID_IM = 19,
> + TOUCH_RAIL_IM = 20,
> + TOUCH_CID_VARIANCE_IM = 21,
> + TOUCH_NSM_FREQUENCY = 22,
> + TOUCH_NSM_STATE = 23,
> + TOUCH_NUM_OF_ACTIVE_OBJECTS = 23,
> + TOUCH_NUM_OF_CPU_CYCLES_USED_SINCE_LAST_FRAME = 24,
> + TOUCH_TUNING_GAUSSIAN_WIDTHS = 0x80,
> + TOUCH_TUNING_SMALL_OBJECT_PARAMS = 0x81,
> + TOUCH_TUNING_0D_BUTTONS_VARIANCE = 0x82,
> + TOUCH_REPORT_GESTURE_SWIPE = 193,
> + TOUCH_REPORT_GESTURE_CIRCLE = 194,
> + TOUCH_REPORT_GESTURE_UNICODE = 195,
> + TOUCH_REPORT_GESTURE_VEE = 196,
> + TOUCH_REPORT_GESTURE_TRIANGLE = 197,
> + TOUCH_REPORT_GESTURE_INFO = 198,
> + TOUCH_REPORT_GESTURE_COORDINATE = 199,
> + TOUCH_REPORT_CUSTOMER_GRIP_INFO = 203,
> +};
> +
> +enum touch_status {
> + LIFT = 0,
> + FINGER = 1,
> + GLOVED_FINGER = 2,
> + NOP = -1,
> +};
> +
> +enum status_code {
> + STATUS_IDLE = 0x00,
> + STATUS_OK = 0x01,
> + STATUS_BUSY = 0x02,
> + STATUS_CONTINUED_READ = 0x03,
> + STATUS_RECEIVE_BUFFER_OVERFLOW = 0x0c,
> + STATUS_PREVIOUS_COMMAND_PENDING = 0x0d,
> + STATUS_NOT_IMPLEMENTED = 0x0e,
> + STATUS_ERROR = 0x0f,
> + STATUS_INVALID = 0xff,
> +};
> +
> +enum report_type {
> + REPORT_IDENTIFY = 0x10,
> + REPORT_TOUCH = 0x11,
> + REPORT_DELTA = 0x12,
> + REPORT_RAW = 0x13,
> + REPORT_DEBUG = 0x14,
> + REPORT_LOG = 0x1d,
> + REPORT_TOUCH_HOLD = 0x20,
> +};
> +
> +enum syna_tcm_oncell_regulators {
> + SYNA_TCM_ONCELL_REGULATOR_VDD,
> + SYNA_TCM_ONCELL_REGULATOR_VCC,
> +};
> +
> +enum boot_mode {
> + MODE_APPLICATION = 0x01,
> + MODE_HOST_DOWNLOAD = 0x02,
> + MODE_BOOTLOADER = 0x0b,
> + MODE_TDDI_BOOTLOADER = 0x0c,
> +};
> +
> +enum app_status {
> + APP_STATUS_OK = 0x00,
> + APP_STATUS_BOOTING = 0x01,
> + APP_STATUS_UPDATING = 0x02,
> + APP_STATUS_BAD_APP_CONFIG = 0xff,
> +};
> +
> +struct syna_tcm_app_info {
> + unsigned char version[2];
> + unsigned char status[2];
> + unsigned char static_config_size[2];
> + unsigned char dynamic_config_size[2];
> + unsigned char app_config_start_write_block[2];
> + unsigned char app_config_size[2];
> + unsigned char max_touch_report_config_size[2];
> + unsigned char max_touch_report_payload_size[2];
> + unsigned char customer_config_id[16];
> + unsigned char max_x[2];
> + unsigned char max_y[2];
> + unsigned char max_objects[2];
> + unsigned char num_of_buttons[2];
> + unsigned char num_of_image_rows[2];
> + unsigned char num_of_image_cols[2];
> + unsigned char has_hybrid_data[2];
> +};
> +
> +struct syna_tcm_identification {
> + unsigned char version;
> + unsigned char mode;
> + unsigned char part_number[16];
> + unsigned char build_id[4];
> + unsigned char max_write_size[2];
> +};
> +
> +struct syna_tcm_message_header {
> + unsigned char marker;
> + unsigned char code;
> + unsigned char length[2];
> +};
> +
> +struct touch_data {
> + unsigned char status;
> + unsigned int x_pos;
> + unsigned int y_pos;
> + unsigned int x_width;
> + unsigned int y_width;
> + unsigned int z;
> +};
> +
> +struct syna_tcm_data {
> + struct i2c_client *client;
> + struct regulator_bulk_data regulators[2];
> + struct input_dev *input;
> + struct gpio_desc *reset_gpio;
> + struct touchscreen_properties prop;
> + struct syna_tcm_identification id_info;
> + struct syna_tcm_app_info app_info;
> +
> + unsigned char *response_buf;
> + unsigned int response_length; // Response length including header
> +
> + unsigned int app_status;
> +
> + unsigned char *report_config;
> + unsigned int report_size;
> +
> + bool initialize_done;
> +
> + unsigned int touchpanel_max_objects;
> +};
> +
> +DECLARE_COMPLETION(response_complete);
> +
> +static inline unsigned int le2_to_uint(const unsigned char *src)
> +{
> + return (unsigned int)src[0] + (unsigned int)src[1] * 0x100;
> +}
> +
> +static inline unsigned int ceil_div(unsigned int dividend, unsigned int divisor)
> +{
> + return (dividend + divisor - 1) / divisor;
> +}
> +
> +static int touch_i2c_continue_read(struct i2c_client *client,
> + unsigned char *data, unsigned short length)
> +{
> + int retval;
> + unsigned char retry;
> + struct i2c_msg msg;
> +
> + msg.addr = client->addr;
> + msg.flags = I2C_M_RD;
> + msg.len = length;
> + msg.buf = data;
> +
> + for (retry = 0; retry < MAX_I2C_RETRY_TIME; retry++) {
> + if (i2c_transfer(client->adapter, &msg, 1) == 1) {
> + retval = length;
> + break;
> + }
> + msleep(20);
> + }
> + if (retry == MAX_I2C_RETRY_TIME) {
> + pr_warn("%s: I2C read over retry limit\n", __func__);
> + retval = -EIO;
> + }
> + return retval;
> +}
> +
> +static int touch_i2c_continue_write(struct i2c_client *client,
> + unsigned char *data, unsigned short length)
> +{
> + int retval;
> + unsigned char retry;
> + struct i2c_msg msg;
> +
> + msg.addr = client->addr;
> + msg.flags = 0;
> + msg.buf = data;
> + msg.len = length;
> +
> + for (retry = 0; retry < MAX_I2C_RETRY_TIME; retry++) {
> + if (i2c_transfer(client->adapter, &msg, 1) == 1) {
> + retval = length;
> + break;
> + }
> + msleep(20);
> + }
> + if (retry == MAX_I2C_RETRY_TIME) {
> + pr_warn("%s: I2C write over retry limit\n", __func__);
> + retval = -EIO;
> + }
> + return retval;
> +}
> +
> +static int syna_tcm_continued_read(struct syna_tcm_data *tcm_info,
> + unsigned int payload_length,
> + unsigned char *message_buffer)
> +{
> + int retval = 0;
> + unsigned char marker = 0, code = 0;
> + unsigned int total_length = 0, remaining_length = 0;
> + unsigned char *temp_buffer;
> +
> + total_length = MESSAGE_HEADER_SIZE + payload_length + 1;
> + remaining_length = total_length - READ_LENGTH;
> +
> + temp_buffer = kmalloc(remaining_length + 2, GFP_KERNEL);
> + if (!temp_buffer)
> + return -ENOMEM;
> +
> + retval = touch_i2c_continue_read(tcm_info->client, temp_buffer,
> + remaining_length + 2);
> + if (retval < 0) {
> + pr_warn("touch_i2c_continue_read failed");
> + return retval;
> + }
> +
> + marker = temp_buffer[0];
> + code = temp_buffer[1];
> +
> + if (marker != MESSAGE_MARKER) {
> + pr_warn("incorrect header marker (0x%02x)\n", marker);
> + return -EIO;
> + }
> +
> + if (code != STATUS_CONTINUED_READ) {
> + pr_warn("incorrect header code (0x%02x)\n", code);
> + return -EIO;
> + }
> +
> + memcpy(&message_buffer[READ_LENGTH], &temp_buffer[2], remaining_length);
> + message_buffer[total_length - 1] = MESSAGE_PADDING;
> + kfree(temp_buffer);
> +
> + return 0;
> +}
> +
> +/**
> + * syna_tcm_raw_write() - write command/data to device without receiving
> + * response
> + *
> + * @tcm_info: handle of core module
> + * @command: command to send to device
> + * @data: data to send to device
> + * @length: length of data in bytes
> + * @add_length: wether the length of the message should be added after the command
> + *
> + * A command and its data, if any, are sent to the device.
> + */
> +static int syna_tcm_raw_write(struct syna_tcm_data *tcm_info,
> + unsigned char command, unsigned char *data,
> + unsigned int length, bool add_length)
> +{
> + int retval = 0;
> + unsigned char *out_buf;
> +
> + unsigned int header_size = add_length && length ? 3 : 1;
> +
> + out_buf = kmalloc(length + header_size, GFP_KERNEL);
> + if (retval < 0)
> + return retval;
> +
> + out_buf[0] = command;
> + if (add_length && length) {
> + out_buf[1] = (unsigned char)length;
> + out_buf[2] = (unsigned char)(length >> 8);
> + }
> +
> + if (length)
> + memcpy(&out_buf[header_size], data, length);
> +
> + retval = touch_i2c_continue_write(tcm_info->client, out_buf,
> + length + header_size);
> + if (retval < 0) {
> + kfree(out_buf);
> + return retval;
> + }
> +
> + kfree(out_buf);
> + return 0;
> +}
> +
> +/**
> + * syna_tcm_read_message() - read message from device
> + *
> + * @tcm_info: handle of core module
> + * @length: length of data in bytes in raw read mode
> + */
> +static int syna_tcm_read_message(struct syna_tcm_data *tcm_info,
> + unsigned int length)
> +{
> + int retval = 0;
> + unsigned int total_length = 0, payload_length = 0;
> + unsigned char *message_buffer;
> + struct syna_tcm_message_header *header = NULL;
> +
> + message_buffer = kmalloc(READ_LENGTH, GFP_KERNEL);
> + if (!message_buffer)
> + return -ENOMEM;
> +
> + retval = touch_i2c_continue_read(tcm_info->client, message_buffer,
> + READ_LENGTH);
> + if (retval < 0)
> + return retval;
> +
> + header = (struct syna_tcm_message_header *)message_buffer;
> + if (header->marker != MESSAGE_MARKER) {
> + pr_warn("wrong header marker:0x%02x\n", header->marker);
> + return -ENXIO;
> + }
> +
> + unsigned char report_code = header->code;
> +
> + payload_length = le2_to_uint(header->length);
> +
> + if (report_code <= STATUS_ERROR || report_code == STATUS_INVALID) {
> + switch (report_code) {
> + case STATUS_OK:
> + break;
> + case STATUS_CONTINUED_READ:
> + case STATUS_IDLE:
> + case STATUS_BUSY:
> + payload_length = 0;
> + kfree(message_buffer);
> + return 0;
> + default:
> + if (report_code != STATUS_ERROR) {
> + pr_warn("IO ERROR");
> + kfree(message_buffer);
> + return -EIO;
> + }
> + }
> + }
> +
> + total_length = MESSAGE_HEADER_SIZE + payload_length + 1;
> +
> + unsigned char *temp_buffer = message_buffer;
> +
> + message_buffer = kmalloc(total_length, GFP_KERNEL);
> + if (!message_buffer)
> + return -ENOMEM;
> +
> + // Copy data already read to message_buffer
> + memcpy(message_buffer, temp_buffer, READ_LENGTH);
> + kfree(temp_buffer);
> +
> + if (payload_length == 0) {
> + message_buffer[total_length - 1] = MESSAGE_PADDING;
> + goto check_padding;
> + }
> +
> + if (MESSAGE_HEADER_SIZE + payload_length > READ_LENGTH) {
> + retval = syna_tcm_continued_read(tcm_info, payload_length,
> + message_buffer);
> + if (retval < 0) {
> + pr_warn("failed to do continued read\n");
> + return retval;
> + };
> + }
> +
> +check_padding:
> + if (message_buffer[total_length - 1] != MESSAGE_PADDING) {
> + pr_warn("missing message padding");
> + return -EIO;
> + }
> +
> + if (tcm_info->response_buf != NULL)
> + kfree(tcm_info->response_buf);
> +
> + tcm_info->response_buf = message_buffer;
> + tcm_info->response_length = total_length;
> +
> + return 0;
> +}
> +
> +static int syna_tcm_write_message(struct syna_tcm_data *tcm_info,
> + unsigned char command, unsigned char *payload,
> + unsigned int length, unsigned char **resp_buf,
> + unsigned int *resp_length)
> +{
> + int retval = 0;
> +
> + if (resp_buf == NULL) {
> + retval = syna_tcm_raw_write(tcm_info, command, payload, length,
> + false);
> + goto exit;
> + }
> + reinit_completion(&response_complete);
> +
> + tcm_info->response_buf = *resp_buf;
> + tcm_info->response_length = *resp_length;
> +
> + // Here write command to device
> + retval = syna_tcm_raw_write(tcm_info, command, payload, length, true);
> + if (retval != 0)
> + goto exit;
> +
> + retval = wait_for_completion_timeout(&response_complete,
> + RESPONSE_TIMEOUT_MS);
> + if (retval == 0) {
> + pr_warn("timed out waiting for response (command 0x%02x)\n",
> + command);
> + retval = -EIO;
> + }
> +
> +exit:
> + if (tcm_info->response_length < 0)
> + return -1;
> + if (resp_buf != NULL) {
> + *resp_buf = tcm_info->response_buf;
> + *resp_length = tcm_info->response_length;
> + }
> +
> + return retval;
> +}
> +
> +static int syna_tcm_set_normal_report_config(struct syna_tcm_data *tcm_info)
> +{
> + int retval;
> + unsigned int idx = 0;
> + unsigned int length;
> +
> + length = le2_to_uint(tcm_info->app_info.max_touch_report_config_size);
> +
> + if (length < TOUCH_REPORT_CONFIG_SIZE) {
> + pr_warn("invalid maximum touch report config size: %d\n",
> + length);
> + return -EINVAL;
> + }
> +
> + unsigned char *report_buf = kmalloc(length, GFP_KERNEL);
> +
> + if (!report_buf)
> + return -ENOMEM;
> +
> + report_buf[idx++] = TOUCH_FOREACH_ACTIVE_OBJECT;
> + report_buf[idx++] = TOUCH_OBJECT_N_INDEX;
> + report_buf[idx++] = 4;
> + report_buf[idx++] = TOUCH_OBJECT_N_CLASSIFICATION;
> + report_buf[idx++] = 4;
> + report_buf[idx++] = TOUCH_OBJECT_N_X_POSITION;
> + report_buf[idx++] = 16;
> + report_buf[idx++] = TOUCH_OBJECT_N_Y_POSITION;
> + report_buf[idx++] = 16;
> + report_buf[idx++] = TOUCH_OBJECT_N_X_WIDTH;
> + report_buf[idx++] = 12;
> + report_buf[idx++] = TOUCH_OBJECT_N_Y_WIDTH;
> + report_buf[idx++] = 12;
> + report_buf[idx++] = TOUCH_FOREACH_END;
> + report_buf[idx++] = TOUCH_END;
> +
> + unsigned char *resp_buf = NULL;
> + unsigned int resp_length = 0;
> +
> + retval = syna_tcm_write_message(tcm_info, CMD_SET_TOUCH_REPORT_CONFIG,
> + report_buf, length, &resp_buf,
> + &resp_length);
> + if (retval < 0) {
> + pr_warn("failed to set report config");
> + return retval;
> + }
> +
> + kfree(resp_buf);
> +
> + return retval;
> +}
> +
> +static int syna_tcm_get_report_config(struct syna_tcm_data *tcm_info)
> +{
> + int retval;
> + unsigned char *resp_buf = NULL;
> + unsigned int resp_length = 0;
> +
> + retval = syna_tcm_write_message(tcm_info, CMD_GET_TOUCH_REPORT_CONFIG,
> + NULL, 0, &resp_buf, &resp_length);
> + if (retval < 0) {
> + pr_warn("failed to write command 0x%02x\n",
> + CMD_GET_TOUCH_REPORT_CONFIG);
> + return retval;
> + }
> +
> + tcm_info->report_size = resp_length - MESSAGE_HEADER_SIZE - 1;
> +
> + kfree(tcm_info->report_config);
> + tcm_info->report_config = kmalloc(tcm_info->report_size, GFP_KERNEL);
> +
> + memcpy(tcm_info->report_config, &resp_buf[MESSAGE_HEADER_SIZE],
> + tcm_info->report_size);
> +
> + return 0;
> +}
> +
> +static int syna_tcm_get_app_info(struct syna_tcm_data *tcm_info)
> +{
> + int retval = 0;
> + unsigned char *resp_buf = NULL;
> + unsigned int resp_length = 0;
> + unsigned int timeout = RESPONSE_TIMEOUT_MS;
> +
> +get_app_info:
> + retval = syna_tcm_write_message(tcm_info, CMD_GET_APPLICATION_INFO,
> + NULL, 0, &resp_buf, &resp_length);
> + if (retval < 0) {
> + pr_warn("failed to write command 0x%02x\n",
> + CMD_GET_APPLICATION_INFO);
> + goto exit;
> + }
> +
> + memcpy(&tcm_info->app_info, &resp_buf[MESSAGE_HEADER_SIZE],
> + sizeof(tcm_info->app_info));
> +
> + tcm_info->app_status = le2_to_uint(tcm_info->app_info.status);
> +
> + if (tcm_info->app_status == APP_STATUS_BOOTING ||
> + tcm_info->app_status == APP_STATUS_UPDATING) {
> + if (timeout > 0) {
> + msleep(APP_STATUS_POLL_MS);
> + timeout -= APP_STATUS_POLL_MS;
> + goto get_app_info;
> + }
> + }
> +
> + retval = 0;
> +
> +exit:
> + kfree(resp_buf);
> +
> + return retval;
> +}
> +
> +static int syna_tcm_identify(struct syna_tcm_data *tcm_info)
> +{
> + int retval = 0;
> + unsigned char *resp_buf = NULL;
> + unsigned int resp_length = 0;
> +
> + retval = syna_tcm_write_message(tcm_info, CMD_IDENTIFY, NULL, 0,
> + &resp_buf, &resp_length);
> + if (retval < 0)
> + goto exit;
> +
> + memcpy(&tcm_info->id_info, &resp_buf[MESSAGE_HEADER_SIZE],
> + sizeof(tcm_info->id_info));
> +
> + if (tcm_info->id_info.mode == MODE_APPLICATION)
> + retval = syna_tcm_get_app_info(tcm_info);
> +
> +exit:
> + kfree(resp_buf);
> +
> + return retval;
> +}
> +
> +static int syna_tcm_run_application_firmware(struct syna_tcm_data *tcm_info)
> +{
> + int retval = 0;
> + unsigned int retry = 3;
> + unsigned char *resp_buf = NULL;
> + unsigned int resp_length = 0;
> +
> +retry:
> + retval = syna_tcm_write_message(tcm_info, CMD_RUN_APPLICATION_FIRMWARE,
> + NULL, 0, &resp_buf, &resp_length);
> +
> + if (retval < 0) {
> + if (retry--)
> + goto retry;
> + goto exit;
> + }
> +
> + retval = syna_tcm_identify(tcm_info);
> + if (retval < 0) {
> + if (retry--)
> + goto retry;
> + goto exit;
> + }
> +
> + pr_info("syna_tcm: boot_mode: 0x%02x", tcm_info->id_info.mode);
> +
> + if (tcm_info->id_info.mode != MODE_APPLICATION) {
> + if (retry--)
> + goto retry;
> + retval = -EINVAL;
> + goto exit;
> + } else if (tcm_info->app_status != APP_STATUS_OK) {
> + pr_warn("syna_tcm: application status = 0x%02x\n",
> + tcm_info->app_status);
> + if (retry--)
> + goto retry;
> + }
> +
> + retval = 0;
> +
> +exit:
> + kfree(resp_buf);
> +
> + return retval;
> +}
> +
> +/*
> + * syna_get_report_data - Retrieve data from touch report
> + *
> + * @tcm_info: handle of tcm module
> + * @offset: start bit of retrieved data
> + * @bits: total bits of retrieved data
> + * @data: pointer of data, at most 4 byte
> + * Retrieve data from the touch report based on the bit offset and bit length
> + * information from the touch report configuration.
> + */
> +static int syna_tcm_get_report_data(unsigned char *report_buf,
> + unsigned int report_buf_length,
> + unsigned int offset, unsigned int num_bits,
> + unsigned int *data)
> +{
> + unsigned char mask = 0;
> + unsigned char byte_data = 0;
> + unsigned int output_data = 0;
> + unsigned int bit_offset = offset % 8;
> + unsigned int byte_offset = offset / 8;
> + unsigned int data_bits = 0;
> + unsigned int available_bits = 0;
> + unsigned int remaining_bits = num_bits;
> +
> + if (num_bits == 0 || num_bits > 32) {
> + pr_warn("report value larger than 32 bits: %d\n", num_bits);
> + memcpy(data, &report_buf[byte_offset], num_bits / 8);
> + return 0;
> + }
> +
> + if ((offset + num_bits) > report_buf_length * 8) {
> + pr_warn("report: offset and bits beyond total read length: %d vs %d bits",
> + offset + num_bits, report_buf_length * 8);
> + *data = 0;
> + return -1;
> + }
> +
> + while (remaining_bits) {
> + byte_data = report_buf[byte_offset];
> + byte_data >>= bit_offset;
> +
> + available_bits = 8 - bit_offset;
> + data_bits = available_bits < remaining_bits ? available_bits :
> + remaining_bits;
> + mask = 0xff >> (8 - data_bits);
> +
> + byte_data &= mask;
> +
> + output_data |= byte_data << (num_bits - remaining_bits);
> +
> + bit_offset = 0;
> + byte_offset += 1;
> + remaining_bits -= data_bits;
> + }
> +
> + *data = output_data;
> +
> + return 0;
> +}
> +
> +static int syna_tcm_parse_touch_report(struct syna_tcm_data *tcm_info)
> +{
> + int config_data_pointer = 0, obj = 0, foreach_start = 0, foreach_end,
> + retval;
> + unsigned int offset = 0, num_bits, data = 0;
> + unsigned char *report_config = tcm_info->report_config;
> + unsigned int config_size = tcm_info->report_size;
> +
> + unsigned char *report = &tcm_info->response_buf[MESSAGE_HEADER_SIZE];
> + unsigned int report_size =
> + tcm_info->response_length - MESSAGE_HEADER_SIZE - 1;
> + unsigned char code;
> +
> + struct touch_data *touch_data =
> + kmalloc(sizeof(touch_data) * tcm_info->touchpanel_max_objects,
> + GFP_KERNEL);
> + memset(touch_data, 0,
> + sizeof(touch_data) * tcm_info->touchpanel_max_objects);
> +
> + while (config_data_pointer < config_size) {
> + code = report_config[config_data_pointer++];
> + switch (code) {
> + case TOUCH_END:
> + goto exit;
> + case TOUCH_FOREACH_ACTIVE_OBJECT:
> + obj = 0;
> + foreach_start = config_data_pointer;
> + if (offset >= report_size * 8)
> + goto exit;
> + break;
> + case TOUCH_FOREACH_END:
> + foreach_end = config_data_pointer;
> + if (offset < report_size * 8)
> + config_data_pointer = foreach_start;
> + break;
> + // Ignored
> + case TOUCH_OBJECT_N_TX_POSITION_TIXELS:
> + case TOUCH_OBJECT_N_RX_POSITION_TIXELS:
> + case TOUCH_FRAME_RATE:
> + case TOUCH_0D_BUTTONS_STATE:
> + case 30: // I don't know what command 30 is and it isn't in the downstream driver. After it comes a length of 8 bits and this is ignored
> + num_bits = report_config[config_data_pointer++];
> + offset += num_bits;
> + break;
> + case TOUCH_PAD_TO_NEXT_BYTE:
> + offset = ceil_div(offset, 8) * 8;
> + break;
> + case TOUCH_OBJECT_N_INDEX:
> + num_bits = report_config[config_data_pointer++];
> + retval = syna_tcm_get_report_data(
> + report, report_size, offset, num_bits, &obj);
> + if (retval < 0) {
> + pr_warn("failed to get object index\n");
> + return retval;
> + }
> + offset += num_bits;
> + break;
> + case TOUCH_OBJECT_N_CLASSIFICATION:
> + num_bits = report_config[config_data_pointer++];
> + retval = syna_tcm_get_report_data(
> + report, report_size, offset, num_bits, &data);
> + if (retval < 0) {
> + pr_warn("failed to get object classification\n");
> + return retval;
> + }
> + if (obj >= tcm_info->touchpanel_max_objects) {
> + pr_warn("too many objects\n");
> + return -1;
> + }
> + touch_data[obj].status = data;
> + offset += num_bits;
> + break;
> + case TOUCH_OBJECT_N_X_POSITION:
> + num_bits = report_config[config_data_pointer++];
> + retval = syna_tcm_get_report_data(
> + report, report_size, offset, num_bits, &data);
> + if (retval < 0) {
> + pr_warn("failed to get object x position\n");
> + return retval;
> + }
> + touch_data[obj].x_pos = data;
> + offset += num_bits;
> + break;
> + case TOUCH_OBJECT_N_Y_POSITION:
> + num_bits = report_config[config_data_pointer++];
> + retval = syna_tcm_get_report_data(
> + report, report_size, offset, num_bits, &data);
> + if (retval < 0) {
> + pr_warn("failed to get object y position\n");
> + return retval;
> + }
> + touch_data[obj].y_pos = data;
> + offset += num_bits;
> + break;
> + case TOUCH_OBJECT_N_Z:
> + num_bits = report_config[config_data_pointer++];
> + retval = syna_tcm_get_report_data(
> + report, report_size, offset, num_bits, &data);
> + if (retval < 0) {
> + pr_warn("failed to get object z\n");
> + return retval;
> + }
> + touch_data[obj].z = data;
> + offset += num_bits;
> + break;
> + case TOUCH_OBJECT_N_X_WIDTH:
> + num_bits = report_config[config_data_pointer++];
> + retval = syna_tcm_get_report_data(
> + report, report_size, offset, num_bits, &data);
> + if (retval < 0) {
> + pr_warn("failed to get object x width\n");
> + return retval;
> + }
> + touch_data[obj].x_width = data;
> + offset += num_bits;
> + break;
> + case TOUCH_OBJECT_N_Y_WIDTH:
> + num_bits = report_config[config_data_pointer++];
> + retval = syna_tcm_get_report_data(
> + report, report_size, offset, num_bits, &data);
> + if (retval < 0) {
> + pr_warn("failed to get object y width\n");
> + return retval;
> + }
> + touch_data[obj].y_width = data;
> + offset += num_bits;
> + break;
> + default:
> + pr_notice("unrecognized touch report config code: %d",
> + code);
> + }
> + }
> +
> +exit:
> + for (int i = 0; i < tcm_info->touchpanel_max_objects; i++) {
> + if (touch_data[i].status == NOP)
> + continue;
> +
> + bool lift = touch_data[i].status == LIFT ? true : false;
> +
> + input_mt_slot(tcm_info->input, i);
> + input_mt_report_slot_state(tcm_info->input, MT_TOOL_FINGER,
> + !lift);
> +
> + int x_width = touch_data[i].x_width;
> + int y_width = touch_data[i].y_width;
> + int major_width = x_width > y_width ? x_width : y_width;
> + int minor_width = x_width > y_width ? y_width : x_width;
> + int x_is_major = x_width > y_width ? true : false;
> +
> + if (!lift) {
> + input_report_abs(tcm_info->input, ABS_MT_POSITION_X,
> + touch_data[i].x_pos);
> + input_report_abs(tcm_info->input, ABS_MT_POSITION_Y,
> + touch_data[i].y_pos);
> + input_report_abs(tcm_info->input, ABS_MT_TOUCH_MAJOR,
> + major_width);
> + input_report_abs(tcm_info->input, ABS_MT_TOUCH_MINOR,
> + minor_width);
> + input_report_abs(tcm_info->input, ABS_MT_ORIENTATION,
> + x_is_major);
> + input_report_abs(tcm_info->input, ABS_MT_PRESSURE,
> + touch_data[i].z);
> + }
> +
> + input_sync(tcm_info->input);
> + }
> +
> + kfree(touch_data);
> + return 0;
> +}
> +
> +static irqreturn_t syna_irq_handler(int irq, void *dev)
> +{
> + int retval;
> + struct syna_tcm_data *tcm_info = dev;
> +
> + retval = syna_tcm_read_message(tcm_info, 0);
> + if (retval < 0) {
> + tcm_info->response_length = -1;
> + goto exit;
> + }
> +
> + if (tcm_info->response_buf[1] == REPORT_TOUCH)
> + syna_tcm_parse_touch_report(tcm_info);
> +
> +exit:
> + if (tcm_info->response_buf[1] <= REPORT_IDENTIFY)
> + complete(&response_complete);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int syna_tcm_power_on(struct syna_tcm_data *tcm_info)
> +{
> + int ret;
> +
> + ret = regulator_bulk_enable(ARRAY_SIZE(tcm_info->regulators),
> + tcm_info->regulators);
> + if (ret)
> + return ret;
> +
> + gpiod_set_value(tcm_info->reset_gpio, false);
> + msleep(POWERUP_TO_RESET_TIME);
> + gpiod_set_value(tcm_info->reset_gpio, true);
> + msleep(RESET_TO_NORMAL_TIME);
> +
> + return 0;
> +}
> +
> +static int syna_tcm_probe(struct i2c_client *client)
> +{
> + struct syna_tcm_data *tcm_info;
> + int err;
> +
> + pr_info("starting probe for syna_tcm_oncell touchscreen");
> +
> + if (!i2c_check_functionality(client->adapter,
> + I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE_DATA |
> + I2C_FUNC_SMBUS_I2C_BLOCK))
> + return -ENODEV;
> +
> + tcm_info = devm_kzalloc(&client->dev, sizeof(*tcm_info), GFP_KERNEL);
> + if (!tcm_info)
> + return -ENOMEM;
> +
> + i2c_set_clientdata(client, tcm_info);
> + tcm_info->client = client;
> + tcm_info->response_buf = NULL;
> +
> + of_property_read_u32(client->dev.of_node, "max-objects",
> + &tcm_info->touchpanel_max_objects);
> +
> + tcm_info->reset_gpio =
> + gpiod_get_index(&client->dev, "reset", 0, GPIOD_OUT_HIGH);
> +
> + tcm_info->regulators[SYNA_TCM_ONCELL_REGULATOR_VDD].supply = "vdd";
> + tcm_info->regulators[SYNA_TCM_ONCELL_REGULATOR_VCC].supply = "vcc";
> + err = devm_regulator_bulk_get(&client->dev,
> + ARRAY_SIZE(tcm_info->regulators),
> + tcm_info->regulators);
> + if (err)
> + return err;
> +
> + // TODO: uncomment once syna_tcm_power_off is implemented
> + // err = devm_add_action_or_reset(&client->dev, syna_tcm_oncell_power_off, tcm_info);
> + // if (err)
> + // return err;
> +
> + err = syna_tcm_power_on(tcm_info);
> + if (err < 0)
> + return err;
> +
> + // This needs to happen before the first write to the device
> + err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
> + syna_irq_handler,
> + IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> + "syna_tcm_oncell_irq", tcm_info);
> + if (err)
> + return err;
> +
> + err = syna_tcm_run_application_firmware(tcm_info);
> + if (err < 0)
> + return err;
> +
> + // err = syna_tcm_set_normal_report_config(tcm_info);
> + // if (err < 0)
> + // pr_err("syna_tcm: failed to set normal touch report config")
> +
> + err = syna_tcm_get_report_config(tcm_info);
> + if (err < 0)
> + return err;
> +
> + tcm_info->input = devm_input_allocate_device(&client->dev);
> + if (!tcm_info->input)
> + return -ENOMEM;
> +
> + tcm_info->input->name = TOUCHPANEL_DEVICE;
> + tcm_info->input->id.bustype = BUS_I2C;
> +
> + input_set_abs_params(tcm_info->input, ABS_MT_POSITION_X, 0,
> + le2_to_uint(tcm_info->app_info.max_x), 0, 0);
> + input_set_abs_params(tcm_info->input, ABS_MT_POSITION_Y, 0,
> + le2_to_uint(tcm_info->app_info.max_y), 0, 0);
> + input_set_abs_params(tcm_info->input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
> + input_set_abs_params(tcm_info->input, ABS_MT_TOUCH_MINOR, 0, 255, 0, 0);
> + input_set_abs_params(tcm_info->input, ABS_MT_PRESSURE, 0, 255, 0, 0);
> +
> + touchscreen_parse_properties(tcm_info->input, true, &tcm_info->prop);
> +
> + err = input_mt_init_slots(tcm_info->input,
> + tcm_info->touchpanel_max_objects,
> + INPUT_MT_DIRECT);
> + if (err)
> + return err;
> +
> + input_set_drvdata(tcm_info->input, tcm_info);
> +
> + err = input_register_device(tcm_info->input);
> + if (err)
> + return err;
> +
> + pr_info("syna_tcm: probe done");
> + tcm_info->initialize_done = true;
> +
> + return 0;
> +}
> +
> +static const struct of_device_id syna_driver_ids[] = {
> + {
> + .compatible = "syna,s3908",
> + },
> + {}
> +};
> +MODULE_DEVICE_TABLE(of, syna_driver_ids);
> +
> +static const struct i2c_device_id syna_i2c_ids[] = { { TOUCHPANEL_DEVICE, 0 },
> + {} };
> +MODULE_DEVICE_TABLE(i2c, syna_i2c_ids);
> +
> +// static const struct dev_pm_ops syna_pm_ops = {
> +// .suspend = syna_i2c_suspend,
> +// .resume = syna_i2c_resume,
> +// };
> +
> +static struct i2c_driver syna_i2c_driver = {
> + .probe = syna_tcm_probe,
> + // .remove = syna_i2c_remove,
> + // .shutdown = syna_tp_shutdown,
> + .id_table = syna_i2c_ids,
> + .driver = {
> + .name = TOUCHPANEL_DEVICE,
> + .of_match_table = syna_driver_ids,
> + // .pm = &syna_pm_ops,
> + },
> +};
> +
> +module_i2c_driver(syna_i2c_driver);