Re: [PATCH v2 1/4] Input: Add driver for Cypress Generation 5 touchscreen

Dmitry Torokhov
2021-11-06T06:47:54Z

Hi Alistair,

On Wed, Nov 03, 2021 at 09:48:27PM +1000, Alistair Francis wrote:
> From: Mylène Josserand <mylene.josserand@bootlin.com>
>
> This is the basic driver for the Cypress TrueTouch Gen5 touchscreen
> controllers. This driver supports only the I2C bus but it uses regmap
> so SPI support could be added later.
> The touchscreen can retrieve some defined zone that are handled as
> buttons (according to the hardware). That is why it handles
> button and multitouch events.
>
> Reviewed-by: Maxime Ripard <maxime.ripard@bootlin.com>
> Signed-off-by: Mylène Josserand <mylene.josserand@bootlin.com>
> Message-Id: <20180703094309.18514-2-mylene.josserand@bootlin.com>
> Signed-off-by: Alistair Francis <alistair@alistair23.me>
> ---
> drivers/input/touchscreen/Kconfig | 14 +
> drivers/input/touchscreen/Makefile | 1 +
> drivers/input/touchscreen/cyttsp5.c | 1135 +++++++++++++++++++++++++++
> 3 files changed, 1150 insertions(+)
> create mode 100644 drivers/input/touchscreen/cyttsp5.c
>
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index d4e74738c5a8..92c8b15b0025 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -284,6 +284,20 @@ config TOUCHSCREEN_CYTTSP4_SPI
> To compile this driver as a module, choose M here: the
> module will be called cyttsp4_spi.
>
> +config TOUCHSCREEN_CYTTSP5
> + tristate "Cypress TrueTouch Gen5 Touchscreen Driver"
> + depends on OF && I2C
> + select REGMAP_I2C
> + select CRC_ITU_T
> + help
> + Driver for Parade TrueTouch Standard Product
> + Generation 5 touchscreen controllers.
> + I2C bus interface support only.
> + Say Y here if you have a Cypress Gen5 touchscreen.
> + If unsure, say N.
> + To compile this driver as a module, choose M here: the
> + module will be called cyttsp5.
> +
> config TOUCHSCREEN_DA9034
> tristate "Touchscreen support for Dialog Semiconductor DA9034"
> depends on PMIC_DA903X
> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
> index 7d34100f7f22..d4d6e56e70de 100644
> --- a/drivers/input/touchscreen/Makefile
> +++ b/drivers/input/touchscreen/Makefile
> @@ -29,6 +29,7 @@ obj-$(CONFIG_TOUCHSCREEN_CYTTSP_SPI) += cyttsp_spi.o
> obj-$(CONFIG_TOUCHSCREEN_CYTTSP4_CORE) += cyttsp4_core.o
> obj-$(CONFIG_TOUCHSCREEN_CYTTSP4_I2C) += cyttsp4_i2c.o cyttsp_i2c_common.o
> obj-$(CONFIG_TOUCHSCREEN_CYTTSP4_SPI) += cyttsp4_spi.o
> +obj-$(CONFIG_TOUCHSCREEN_CYTTSP5) += cyttsp5.o
> obj-$(CONFIG_TOUCHSCREEN_DA9034) += da9034-ts.o
> obj-$(CONFIG_TOUCHSCREEN_DA9052) += da9052_tsi.o
> obj-$(CONFIG_TOUCHSCREEN_DYNAPRO) += dynapro.o
> diff --git a/drivers/input/touchscreen/cyttsp5.c b/drivers/input/touchscreen/cyttsp5.c
> new file mode 100644
> index 000000000000..77938cb0c4bb
> --- /dev/null
> +++ b/drivers/input/touchscreen/cyttsp5.c
> @@ -0,0 +1,1135 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Parade TrueTouch(TM) Standard Product V5 Module.
> + *
> + * Copyright (C) 2015 Parade Technologies
> + * Copyright (C) 2012-2015 Cypress Semiconductor
> + * Copyright (C) 2018 Bootlin
> + *
> + * Authors: Mylène Josserand <mylene.josserand@bootlin.com>
> + * Alistair Francis <alistair@alistair23.me>
> + *
> + */
> +
> +#include <asm/unaligned.h>
> +#include <linux/crc-itu-t.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/gpio.h>
> +#include <linux/input/mt.h>
> +#include <linux/input/touchscreen.h>
> +#include <linux/interrupt.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/regmap.h>
> +
> +#define CYTTSP5_NAME "cyttsp5"
> +#define CY_I2C_DATA_SIZE (2 * 256)
> +#define HID_VERSION 0x0100
> +#define CY_MAX_INPUT 512
> +#define CYTTSP5_PREALLOCATED_CMD_BUFFER 32
> +#define CY_BITS_PER_BTN 1
> +#define CY_NUM_BTN_EVENT_ID ((1 << CY_BITS_PER_BTN) - 1)
> +
> +#define MAX_AREA 255
> +#define HID_OUTPUT_BL_SOP 0x1
> +#define HID_OUTPUT_BL_EOP 0x17
> +#define HID_OUTPUT_BL_LAUNCH_APP 0x3B
> +#define HID_OUTPUT_BL_LAUNCH_APP_SIZE 11
> +#define HID_OUTPUT_GET_SYSINFO 0x2
> +#define HID_OUTPUT_GET_SYSINFO_SIZE 5
> +#define HID_OUTPUT_MAX_CMD_SIZE 12
> +
> +#define HID_DESC_REG 0x1
> +#define HID_INPUT_REG 0x3
> +#define HID_OUTPUT_REG 0x4
> +
> +#define REPORT_ID_TOUCH 0x1
> +#define REPORT_ID_BTN 0x3
> +#define REPORT_SIZE_5 5
> +#define REPORT_SIZE_8 8
> +#define REPORT_SIZE_16 16
> +
> +/* Touch reports offsets */
> +/* Header offsets */
> +#define TOUCH_REPORT_DESC_HDR_CONTACTCOUNT 16
> +/* Record offsets */
> +#define TOUCH_REPORT_DESC_CONTACTID 8
> +#define TOUCH_REPORT_DESC_X 16
> +#define TOUCH_REPORT_DESC_Y 32
> +#define TOUCH_REPORT_DESC_P 48
> +#define TOUCH_REPORT_DESC_MAJ 56
> +#define TOUCH_REPORT_DESC_MIN 64
> +
> +/* HID */
> +#define HID_TOUCH_REPORT_ID 0x1
> +#define HID_BTN_REPORT_ID 0x3
> +#define HID_APP_RESPONSE_REPORT_ID 0x1F
> +#define HID_APP_OUTPUT_REPORT_ID 0x2F
> +#define HID_BL_RESPONSE_REPORT_ID 0x30
> +#define HID_BL_OUTPUT_REPORT_ID 0x40
> +
> +#define HID_OUTPUT_RESPONSE_REPORT_OFFSET 2
> +#define HID_OUTPUT_RESPONSE_CMD_OFFSET 4
> +#define HID_OUTPUT_RESPONSE_CMD_MASK 0x7F
> +
> +#define HID_SYSINFO_SENSING_OFFSET 33
> +#define HID_SYSINFO_BTN_OFFSET 48
> +#define HID_SYSINFO_BTN_MASK 0xFF
> +#define HID_SYSINFO_MAX_BTN 8
> +
> +/* Timeout in ms */
> +#define CY_HID_OUTPUT_TIMEOUT 200
> +#define CY_HID_OUTPUT_GET_SYSINFO_TIMEOUT 3000
> +#define CY_HID_GET_HID_DESCRIPTOR_TIMEOUT 4000
> +
> +/* maximum number of concurrent tracks */
> +#define TOUCH_REPORT_SIZE 10
> +#define TOUCH_INPUT_HEADER_SIZE 7
> +#define BTN_REPORT_SIZE 9
> +#define BTN_INPUT_HEADER_SIZE 5
> +
> +#define MAX_CY_TCH_T_IDS 32
> +
> +/* All usage pages for Touch Report */
> +#define TOUCH_REPORT_USAGE_PG_X 0x00010030
> +#define TOUCH_REPORT_USAGE_PG_Y 0x00010031
> +#define TOUCH_REPORT_USAGE_PG_P 0x000D0030
> +#define TOUCH_REPORT_USAGE_PG_CONTACTID 0x000D0051
> +#define TOUCH_REPORT_USAGE_PG_CONTACTCOUNT 0x000D0054
> +#define TOUCH_REPORT_USAGE_PG_MAJ 0xFF010062
> +#define TOUCH_REPORT_USAGE_PG_MIN 0xFF010063
> +#define TOUCH_COL_USAGE_PG 0x000D0022
> +
> +/* helpers */
> +#define HI_BYTE(x) ((u8)(((x) >> 8) & 0xFF))
> +#define LOW_BYTE(x) ((u8)((x) & 0xFF))
> +
> +/* System Information interface definitions */
> +struct cyttsp5_sensing_conf_data_dev {
> + u8 electrodes_x;
> + u8 electrodes_y;
> + __le16 len_x;
> + __le16 len_y;
> + __le16 res_x;
> + __le16 res_y;
> + __le16 max_z;
> + u8 origin_x;
> + u8 origin_y;
> + u8 btn;
> + u8 scan_mode;
> + u8 max_num_of_tch_per_refresh_cycle;
> +} __packed;
> +
> +struct cyttsp5_sensing_conf_data {
> + u16 res_x;
> + u16 res_y;
> + u16 max_z;
> + u16 len_x;
> + u16 len_y;
> + u8 origin_x;
> + u8 origin_y;
> + u8 max_tch;
> +};
> +
> +enum hid_cmd_state {
> + HID_CMD_DONE,
> + HID_CMD_BUSY,
> +};
> +
> +enum cyttsp5_tch_abs { /* for ordering within the extracted touch data array */
> + CY_TCH_X, /* X */
> + CY_TCH_Y, /* Y */
> + CY_TCH_P, /* P (Z) */
> + CY_TCH_T, /* TOUCH ID */
> + CY_TCH_MAJ, /* TOUCH_MAJOR */
> + CY_TCH_MIN, /* TOUCH_MINOR */
> + CY_TCH_NUM_ABS,
> +};
> +
> +struct cyttsp5_tch_abs_params {
> + size_t ofs; /* abs byte offset */
> + size_t size; /* size in bits */
> + size_t min; /* min value */
> + size_t max; /* max value */
> + size_t bofs; /* bit offset */
> +};
> +
> +struct cyttsp5_touch {
> + int hdr;
> + int abs[CY_TCH_NUM_ABS];
> +};
> +
> +struct cyttsp5_sysinfo {
> + struct cyttsp5_sensing_conf_data sensing_conf_data;
> + int num_btns;
> + struct cyttsp5_tch_abs_params tch_hdr;
> + struct cyttsp5_tch_abs_params tch_abs[CY_TCH_NUM_ABS];
> + u32 key_code[HID_SYSINFO_MAX_BTN];
> + u8 *xy_mode;
> + u8 *xy_data;
> +};
> +
> +struct cyttsp5_hid_desc {
> + __le16 hid_desc_len;
> + u8 packet_id;
> + u8 reserved_byte;
> + __le16 bcd_version;
> + __le16 report_desc_len;
> + __le16 report_desc_register;
> + __le16 input_register;
> + __le16 max_input_len;
> + __le16 output_register;
> + __le16 max_output_len;
> + __le16 command_register;
> + __le16 data_register;
> + __le16 vendor_id;
> + __le16 product_id;
> + __le16 version_id;
> + u8 reserved[4];
> +} __packed;
> +
> +struct cyttsp5 {
> + struct device *dev;
> + struct mutex system_lock;
> + wait_queue_head_t wait_q;

Looking through the driver I think what you need is completion.

> + struct cyttsp5_sysinfo sysinfo;
> + int hid_cmd_state;
> + struct cyttsp5_hid_desc hid_desc;
> + u8 cmd_buf[CYTTSP5_PREALLOCATED_CMD_BUFFER];
> + u8 input_buf[CY_MAX_INPUT];
> + u8 response_buf[CY_MAX_INPUT];
> + struct gpio_desc *reset_gpio;
> + struct input_dev *input;
> + char phys[NAME_MAX];
> + int num_prv_rec;
> + struct regmap *regmap;
> + struct touchscreen_properties prop;
> + struct regulator *vdd;
> +};
> +
> +/*
> + * For what understood in the datasheet, the register does not
> + * matter. For consistency, used the Input Register address
> + * but it does mean anything to the device. The important data
> + * to send is the I2C address
> + */
> +static int cyttsp5_read(struct cyttsp5 *ts, u8 *buf, u32 max)
> +{
> + int rc;

Please call this "error". Also elsewhere, variables that hold either
error code or success (0) should be called "error".

> + u32 size;
> + u8 temp[2];
> +
> + if (!buf)
> + return -EINVAL;

This is an internal function. How can it be called with NULL buffer?

> +
> + /* Read the frame to retrieve the size */
> + rc = regmap_bulk_read(ts->regmap, HID_INPUT_REG, temp, 2);

sizeof(temp)

> + if (rc < 0)

regmap_bulk_read() retirns 0 on success, so the check should be

if (error)

> + return rc;
> +
> + size = get_unaligned_le16(temp);
> + if (!size || size == 2)
> + return 0;
> +
> + if (size > max)
> + return -EINVAL;
> +
> + /* Get the real value */
> + return regmap_bulk_read(ts->regmap, HID_INPUT_REG, buf, size);
> +}
> +
> +static int cyttsp5_write(struct cyttsp5 *ts, unsigned int reg, u8 *data,
> + size_t size)
> +{
> + u8 cmd[HID_OUTPUT_MAX_CMD_SIZE];
> +
> + if (size + 1 > HID_OUTPUT_MAX_CMD_SIZE) {
> + return -ENOMEM;

Maybe -E2BIG or -EINVAL.

> + }

Unnecessary curly braces.

> +
> + /* High bytes of register address needed as first byte of cmd */
> + cmd[0] = HI_BYTE(reg);
> +
> + /* Copy the rest of the data */
> + if (data)
> + memcpy(&cmd[1], data, size);
> +
> + /* The hardware wants to receive a frame with the address register
> + * contains in the first two bytes. As the regmap_write function
> + * add the register adresse in the frame, we use the LOW_BYTE as
> + * first frame byte for the address register and the first
> + * data byte is the high register + left of the cmd to send
> + */
> + return regmap_bulk_write(ts->regmap, LOW_BYTE(reg), cmd, size + 1);
> +}
> +
> +static void cyttsp5_final_sync(struct input_dev *input, int max_slots,
> + unsigned long *ids)
> +{
> + int t;
> +
> + for (t = 0; t < max_slots; t++) {
> + if (test_bit(t, ids))
> + continue;
> + input_mt_slot(input, t);
> + input_mt_report_slot_state(input, MT_TOOL_FINGER, false);
> + }
> +
> + input_sync(input);
> +}
> +
> +static void cyttsp5_report_slot_liftoff(struct cyttsp5 *ts, int max_slots)
> +{
> + int t;
> +
> + if (ts->num_prv_rec == 0)
> + return;
> +
> + for (t = 0; t < max_slots; t++) {
> + input_mt_slot(ts->input, t);
> + input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, false);
> + }
> +}
> +
> +static void cyttsp5_mt_lift_all(struct cyttsp5 *ts)
> +{
> + struct cyttsp5_sysinfo *si = &ts->sysinfo;
> + int max = si->tch_abs[CY_TCH_T].max;
> +
> + if (ts->num_prv_rec != 0) {
> + cyttsp5_report_slot_liftoff(ts, max);
> + input_sync(ts->input);
> + ts->num_prv_rec = 0;
> + }
> +}
> +
> +static void cyttsp5_get_touch_axis(int *axis, int size, int max, u8 *xy_data,
> + int bofs)
> +{
> + int nbyte;
> +
> + for (nbyte = 0, *axis = 0; nbyte < size; nbyte++)
> + *axis = *axis + ((xy_data[nbyte] >> bofs) << (nbyte * 8));
> +
> + *axis &= max - 1;

Can it be that max is not power of 2?

> +}
> +
> +static void cyttsp5_get_touch_record(struct cyttsp5 *ts,
> + struct cyttsp5_touch *touch, u8 *xy_data)
> +{
> + struct cyttsp5_sysinfo *si = &ts->sysinfo;
> + enum cyttsp5_tch_abs abs;
> +
> + for (abs = CY_TCH_X; abs < CY_TCH_NUM_ABS; abs++) {
> + cyttsp5_get_touch_axis(&touch->abs[abs],
> + si->tch_abs[abs].size,
> + si->tch_abs[abs].max,
> + xy_data + si->tch_abs[abs].ofs,
> + si->tch_abs[abs].bofs);
> + }

Unnecessary curly braces.

> +}
> +
> +static void cyttsp5_get_mt_touches(struct cyttsp5 *ts,
> + struct cyttsp5_touch *tch, int num_cur_tch)
> +{
> + struct cyttsp5_sysinfo *si = &ts->sysinfo;
> + int i, t = 0;
> + DECLARE_BITMAP(ids, MAX_CY_TCH_T_IDS);
> + u8 *tch_addr;
> + int tmp;
> +
> + bitmap_zero(ids, MAX_CY_TCH_T_IDS);
> + memset(tch->abs, 0, sizeof(tch->abs));
> +
> + for (i = 0; i < num_cur_tch; i++) {
> + tch_addr = si->xy_data + (i * TOUCH_REPORT_SIZE);
> + cyttsp5_get_touch_record(ts, tch, tch_addr);
> +
> + /* Convert MAJOR/MINOR from mm to resolution */
> + tmp = tch->abs[CY_TCH_MAJ] * 100 * si->sensing_conf_data.res_x;
> + tch->abs[CY_TCH_MAJ] = tmp / si->sensing_conf_data.len_x;
> + tmp = tch->abs[CY_TCH_MIN] * 100 * si->sensing_conf_data.res_x;
> + tch->abs[CY_TCH_MIN] = tmp / si->sensing_conf_data.len_x;
> +
> + t = tch->abs[CY_TCH_T];
> + input_mt_slot(ts->input, t);
> + input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
> + __set_bit(t, ids);
> +
> + /* position and pressure fields */
> + input_report_abs(ts->input, ABS_MT_POSITION_X,
> + tch->abs[CY_TCH_X]);
> + input_report_abs(ts->input, ABS_MT_POSITION_Y,
> + tch->abs[CY_TCH_Y]);
> + input_report_abs(ts->input, ABS_MT_PRESSURE,
> + tch->abs[CY_TCH_P]);
> +
> + /* Get the extended touch fields */
> + input_report_abs(ts->input, ABS_MT_TOUCH_MAJOR,
> + tch->abs[CY_TCH_MAJ]);
> + input_report_abs(ts->input, ABS_MT_TOUCH_MINOR,
> + tch->abs[CY_TCH_MIN]);
> +
> + touchscreen_report_pos(ts->input, &ts->prop,
> + tch->abs[CY_TCH_X], tch->abs[CY_TCH_Y],
> + true);

I have no idea why you first report position manually (without applying
transformation) and then finally use touchscreen_report_pos() to report
is again, now properly.

> + }
> +
> + cyttsp5_final_sync(ts->input, si->tch_abs[CY_TCH_T].max, ids);

I think if you use INPUT_MT_DROP_UNUSED when initializing slots and call
input_mt_sync_frame() then cyttsp5_final_sync() will not be needed.

> +
> + ts->num_prv_rec = num_cur_tch;
> +}
> +
> +/* read xy_data for all current touches */
> +static int cyttsp5_xy_worker(struct cyttsp5 *ts)
> +{
> + struct device *dev = ts->dev;
> + struct cyttsp5_sysinfo *si = &ts->sysinfo;
> + int max_tch = si->sensing_conf_data.max_tch;
> + struct cyttsp5_touch tch;
> + u8 num_cur_tch;
> +
> + cyttsp5_get_touch_axis(&tch.hdr, si->tch_hdr.size,

I am struggling to understand why this member is called "hdr" and why it
is a part of cyttsp5_touch.

> + si->tch_hdr.max,
> + si->xy_mode + 3 + si->tch_hdr.ofs,
> + si->tch_hdr.bofs);
> +
> + num_cur_tch = tch.hdr;
> + if (num_cur_tch > max_tch) {
> + dev_err(dev, "Num touch err detected (n=%d)\n", num_cur_tch);
> + num_cur_tch = max_tch;
> + }
> +
> + if (num_cur_tch == 0 && ts->num_prv_rec == 0)
> + return 0;
> +
> + /* extract xy_data for all currently reported touches */
> + if (num_cur_tch)
> + cyttsp5_get_mt_touches(ts, &tch, num_cur_tch);
> + else
> + cyttsp5_mt_lift_all(ts);

Not needed with INPUT_MT_DROP_UNUSED.

> +
> + return 0;
> +}
> +
> +static int cyttsp5_mt_attention(struct device *dev)
> +{
> + struct cyttsp5 *ts = dev_get_drvdata(dev);
> + struct cyttsp5_sysinfo *si = &ts->sysinfo;
> + int rc;
> +
> + if (si->xy_mode[2] != HID_TOUCH_REPORT_ID)
> + return 0;

It is only ever called with this condition, why do we need to check
this again?

> +
> + /* core handles handshake */
> + rc = cyttsp5_xy_worker(ts);
> + if (rc < 0)
> + dev_err(dev, "xy_worker error r=%d\n", rc);
> +
> + return rc;
> +}
> +
> +static int cyttsp5_setup_input_device(struct device *dev)
> +{
> + struct cyttsp5 *ts = dev_get_drvdata(dev);
> + struct cyttsp5_sysinfo *si = &ts->sysinfo;
> + int max_x, max_y, max_p;
> + int max_x_tmp, max_y_tmp;
> + int rc;
> +
> + __set_bit(EV_ABS, ts->input->evbit);

input_set_abs_params() does this I believe.

> + __set_bit(EV_REL, ts->input->evbit);

I do not believe the driver emits any EV_REL events.

> + __set_bit(EV_KEY, ts->input->evbit);

I think I saw it done elsewhere already.

> +
> + max_x_tmp = si->sensing_conf_data.res_x;
> + max_y_tmp = si->sensing_conf_data.res_y;
> + max_x = max_x_tmp - 1;
> + max_y = max_y_tmp - 1;
> + max_p = si->sensing_conf_data.max_z;
> +
> + input_mt_init_slots(ts->input, si->tch_abs[CY_TCH_T].max, 0);

Error handling. You also want to use INPUT_MT_POINTER and potentially
INPUT_MT_DROP_UNUSED.

> +
> + __set_bit(ABS_MT_POSITION_X, ts->input->absbit);
> + __set_bit(ABS_MT_POSITION_Y, ts->input->absbit);
> + __set_bit(ABS_MT_PRESSURE, ts->input->absbit);

These 3 are not needed.

> +
> + input_set_abs_params(ts->input, ABS_MT_POSITION_X, 0, max_x, 0, 0);
> + input_set_abs_params(ts->input, ABS_MT_POSITION_Y, 0, max_y, 0, 0);
> + input_set_abs_params(ts->input, ABS_MT_PRESSURE, 0, max_p, 0, 0);
> +
> + input_set_abs_params(ts->input, ABS_MT_TOUCH_MAJOR, 0, MAX_AREA, 0, 0);
> + input_set_abs_params(ts->input, ABS_MT_TOUCH_MINOR, 0, MAX_AREA, 0, 0);
> +
> + rc = input_register_device(ts->input);
> + if (rc < 0)
> + dev_err(dev, "Error, failed register input device r=%d\n", rc);
> +
> + return rc;
> +}
> +
> +#ifdef CONFIG_OF
> +static int cyttsp5_parse_dt_key_code(struct device *dev)
> +{
> + struct cyttsp5 *ts = dev_get_drvdata(dev);
> + struct cyttsp5_sysinfo *si = &ts->sysinfo;
> + struct device_node *np;
> + int i;
> +
> + np = dev->of_node;
> + if (!np)
> + return -EINVAL;
> +
> + if (!si->num_btns)
> + return 0;
> +
> + /* Initialize the button to RESERVED */
> + for (i = 0; i < si->num_btns; i++)
> + si->key_code[i] = KEY_RESERVED;
> +
> + return of_property_read_u32_array(np, "linux,keycodes",
> + si->key_code, si->num_btns);

I would use device_property_read_u32_array() instead and did not make it
limited to OF.

> +}
> +#else
> +static int cyttsp5_parse_dt_key_code(struct device *dev)
> +{
> + struct cyttsp5 *ts = dev_get_drvdata(dev);
> + struct cyttsp5_sysinfo *si = &ts->sysinfo;
> + int i;
> +
> + if (!si->num_btns)
> + return 0;
> +
> + /* Initialize the button to RESERVED */
> + for (i = 0; i < si->num_btns; i++)
> + si->key_code[i] = KEY_RESERVED;
> +
> + return 0;
> +}
> +#endif
> +
> +static int cyttsp5_btn_attention(struct device *dev)
> +{
> + struct cyttsp5 *ts = dev_get_drvdata(dev);
> + struct cyttsp5_sysinfo *si = &ts->sysinfo;
> + int cur_btn;
> + int cur_btn_state;
> +
> + if (si->xy_mode[2] != HID_BTN_REPORT_ID || !si->num_btns)
> + return 0;
> +
> + /* extract button press/release touch information */
> + for (cur_btn = 0; cur_btn < si->num_btns; cur_btn++) {
> + /* Get current button state */
> + cur_btn_state = (si->xy_data[0] >> (cur_btn * CY_BITS_PER_BTN))
> + & CY_NUM_BTN_EVENT_ID;
> +
> + input_report_key(ts->input, si->key_code[cur_btn],
> + cur_btn_state);
> + input_sync(ts->input);
> + }
> +
> + return 0;
> +}
> +
> +static u16 cyttsp5_compute_crc(u8 *buf, u32 size)
> +{
> + u16 remainder = 0xFFFF;
> + u16 xor_mask = 0x0000;
> + u32 index;
> + u32 byte_value;
> + u32 table_index;
> + u32 crc_bit_width = sizeof(u16) * 8;
> +
> + /* Divide the message by polynomial, via the table. */
> + for (index = 0; index < size; index++) {
> + byte_value = buf[index];
> + table_index = ((byte_value >> 4) & 0x0F)
> + ^ (remainder >> (crc_bit_width - 4));
> + remainder = crc_itu_t_table[table_index]
> + ^ (remainder << 4);
> + table_index = (byte_value & 0x0F)
> + ^ (remainder >> (crc_bit_width - 4));
> + remainder = crc_itu_t_table[table_index]
> + ^ (remainder << 4);
> + }
> +
> + /* Perform the final remainder CRC. */
> + return remainder ^ xor_mask;

Do we have matching implementation in lib/crc* by any chance?

> +}
> +
> +static int cyttsp5_validate_cmd_response(struct cyttsp5 *ts, u8 code)
> +{
> + u16 size, crc;
> + u8 status, offset;
> + int command_code;
> +
> + size = get_unaligned_le16(&ts->response_buf[0]);
> +
> + if (!size)
> + return 0;
> +
> + offset = ts->response_buf[HID_OUTPUT_RESPONSE_REPORT_OFFSET];

This is definitely not an "offset".

> +
> + if (offset == HID_BL_RESPONSE_REPORT_ID) {

switch (report_id) {

> + if (ts->response_buf[4] != HID_OUTPUT_BL_SOP) {
> + dev_err(ts->dev, "HID output response, wrong SOP\n");
> + return -EPROTO;
> + }
> +
> + if (ts->response_buf[size - 1] != HID_OUTPUT_BL_EOP) {
> + dev_err(ts->dev, "HID output response, wrong EOP\n");
> + return -EPROTO;
> + }
> +
> + crc = cyttsp5_compute_crc(&ts->response_buf[4], size - 7);
> + if (ts->response_buf[size - 3] != LOW_BYTE(crc) ||
> + ts->response_buf[size - 2] != HI_BYTE(crc)) {
> + dev_err(ts->dev, "HID output response, wrong CRC 0x%X\n",
> + crc);
> + return -EPROTO;
> + }
> +
> + status = ts->response_buf[5];
> + if (status) {
> + dev_err(ts->dev, "HID output response, ERROR:%d\n",
> + status);
> + return -EPROTO;
> + }
> + }
> +
> + if (offset == HID_APP_RESPONSE_REPORT_ID) {
> + command_code = ts->response_buf[HID_OUTPUT_RESPONSE_CMD_OFFSET]
> + & HID_OUTPUT_RESPONSE_CMD_MASK;
> + if (command_code != code) {
> + dev_err(ts->dev,
> + "HID output response, wrong command_code:%X\n",
> + command_code);
> + return -EPROTO;
> + }
> + }
> +
> + return 0;
> +}
> +
> +static void cyttsp5_si_get_btn_data(struct cyttsp5 *ts)
> +{
> + struct cyttsp5_sysinfo *si = &ts->sysinfo;
> + int i;
> + unsigned int btns = ts->response_buf[HID_SYSINFO_BTN_OFFSET]
> + & HID_SYSINFO_BTN_MASK;
> +
> + si->num_btns = 0;
> + for (i = 0; i < HID_SYSINFO_MAX_BTN; i++) {
> + if (btns & BIT(i))
> + si->num_btns++;
> + }

hweight*()?

> +}
> +
> +static int cyttsp5_get_sysinfo_regs(struct cyttsp5 *ts)
> +{
> + struct cyttsp5_sensing_conf_data *scd = &ts->sysinfo.sensing_conf_data;
> + struct cyttsp5_sensing_conf_data_dev *scd_dev =
> + (struct cyttsp5_sensing_conf_data_dev *)
> + &ts->response_buf[HID_SYSINFO_SENSING_OFFSET];
> + struct cyttsp5_sysinfo *si = &ts->sysinfo;
> +
> + cyttsp5_si_get_btn_data(ts);
> +
> + scd->max_tch = scd_dev->max_num_of_tch_per_refresh_cycle;
> + scd->res_x = get_unaligned_le16(&scd_dev->res_x);
> + scd->res_y = get_unaligned_le16(&scd_dev->res_y);
> + scd->max_z = get_unaligned_le16(&scd_dev->max_z);
> + scd->len_x = get_unaligned_le16(&scd_dev->len_x);
> + scd->len_y = get_unaligned_le16(&scd_dev->len_y);
> +
> + si->xy_data = devm_kzalloc(ts->dev, scd->max_tch * TOUCH_REPORT_SIZE,
> + GFP_KERNEL);

What it the absolute maximum for tracked contacts? I wonder if it makes
sense to allocate this buffer separately.

> + if (!si->xy_data)
> + return -ENOMEM;
> +
> + si->xy_mode = devm_kzalloc(ts->dev, TOUCH_INPUT_HEADER_SIZE,
> + GFP_KERNEL);
> + if (!si->xy_mode)
> + return -ENOMEM;

Why do we need to allocate 7 bytes separately?

> +
> + return 0;
> +}
> +
> +static int cyttsp5_hid_output_get_sysinfo(struct cyttsp5 *ts)
> +{
> + int rc;
> + u8 cmd[HID_OUTPUT_GET_SYSINFO_SIZE];
> +
> + ts->hid_cmd_state = HID_CMD_BUSY;
> +
> + /* HI bytes of Output register address */
> + cmd[0] = LOW_BYTE(HID_OUTPUT_GET_SYSINFO_SIZE);
> + cmd[1] = HI_BYTE(HID_OUTPUT_GET_SYSINFO_SIZE);
> + cmd[2] = HID_APP_OUTPUT_REPORT_ID;
> + cmd[3] = 0x0; /* Reserved */
> + cmd[4] = HID_OUTPUT_GET_SYSINFO;
> +
> + rc = cyttsp5_write(ts, HID_OUTPUT_REG, cmd,
> + HID_OUTPUT_GET_SYSINFO_SIZE);
> + if (rc) {
> + dev_err(ts->dev, "Failed to write command %d", rc);
> + goto error;
> + }
> +
> + rc = wait_event_timeout(ts->wait_q, (ts->hid_cmd_state == HID_CMD_DONE),
> + msecs_to_jiffies(CY_HID_OUTPUT_GET_SYSINFO_TIMEOUT));
> + if (!rc) {
> + dev_err(ts->dev, "HID output cmd execution timed out\n");
> + rc = -ETIME;
> + goto error;
> + }
> +
> + rc = cyttsp5_validate_cmd_response(ts, HID_OUTPUT_GET_SYSINFO);
> + if (rc) {
> + dev_err(ts->dev, "Validation of the response failed\n");
> + goto error;
> + }
> +
> + return cyttsp5_get_sysinfo_regs(ts);
> +
> +error:
> + mutex_lock(&ts->system_lock);
> + ts->hid_cmd_state = HID_CMD_DONE;
> + mutex_unlock(&ts->system_lock);
> + return rc;
> +}
> +
> +static int cyttsp5_hid_output_bl_launch_app(struct cyttsp5 *ts)
> +{
> + int rc;
> + u8 cmd[HID_OUTPUT_BL_LAUNCH_APP];
> + u16 crc;
> +
> + mutex_lock(&ts->system_lock);
> + ts->hid_cmd_state = HID_CMD_BUSY;
> + mutex_unlock(&ts->system_lock);
> +
> + cmd[0] = LOW_BYTE(HID_OUTPUT_BL_LAUNCH_APP_SIZE);
> + cmd[1] = HI_BYTE(HID_OUTPUT_BL_LAUNCH_APP_SIZE);
> + cmd[2] = HID_BL_OUTPUT_REPORT_ID;
> + cmd[3] = 0x0; /* Reserved */
> + cmd[4] = HID_OUTPUT_BL_SOP;
> + cmd[5] = HID_OUTPUT_BL_LAUNCH_APP;
> + cmd[6] = 0x0; /* Low bytes of data */
> + cmd[7] = 0x0; /* Hi bytes of data */
> + crc = cyttsp5_compute_crc(&cmd[4], 4);
> + cmd[8] = LOW_BYTE(crc);
> + cmd[9] = HI_BYTE(crc);
> + cmd[10] = HID_OUTPUT_BL_EOP;
> +
> + rc = cyttsp5_write(ts, HID_OUTPUT_REG, cmd,
> + HID_OUTPUT_BL_LAUNCH_APP_SIZE);
> + if (rc) {
> + dev_err(ts->dev, "Failed to write command %d", rc);
> + goto error;
> + }
> +
> + rc = wait_event_timeout(ts->wait_q, (ts->hid_cmd_state == HID_CMD_DONE),
> + msecs_to_jiffies(CY_HID_OUTPUT_TIMEOUT));
> + if (!rc) {
> + dev_err(ts->dev, "HID output cmd execution timed out\n");
> + rc = -ETIME;
> + goto error;
> + }
> +
> + rc = cyttsp5_validate_cmd_response(ts, HID_OUTPUT_BL_LAUNCH_APP);
> + if (rc) {
> + dev_err(ts->dev, "Validation of the response failed\n");
> + goto error;
> + }
> +
> + return rc;
> +
> +error:
> + mutex_lock(&ts->system_lock);
> + ts->hid_cmd_state = HID_CMD_DONE;
> + mutex_unlock(&ts->system_lock);
> +
> + return rc;
> +}
> +
> +static int cyttsp5_get_hid_descriptor(struct cyttsp5 *ts,
> + struct cyttsp5_hid_desc *desc)
> +{
> + struct device *dev = ts->dev;
> + __le16 hid_desc_register = HID_DESC_REG;
> + int rc;
> + u8 cmd[2];
> +
> + /* Read HID descriptor length and version */
> + mutex_lock(&ts->system_lock);
> + ts->hid_cmd_state = HID_CMD_BUSY;
> + mutex_unlock(&ts->system_lock);
> +
> + /* Set HID descriptor register */
> + memcpy(cmd, &hid_desc_register, sizeof(hid_desc_register));
> +
> + rc = cyttsp5_write(ts, HID_DESC_REG, NULL, 0);
> + if (rc < 0) {
> + dev_err(dev, "Failed to get HID descriptor, rc=%d\n", rc);
> + goto error;
> + }
> +
> + rc = wait_event_timeout(ts->wait_q, (ts->hid_cmd_state == HID_CMD_DONE),
> + msecs_to_jiffies(CY_HID_GET_HID_DESCRIPTOR_TIMEOUT));
> + if (!rc) {
> + dev_err(ts->dev, "HID get descriptor timed out\n");
> + rc = -ETIME;
> + goto error;
> + }
> +
> + memcpy(desc, ts->response_buf, sizeof(struct cyttsp5_hid_desc));
> +
> + /* Check HID descriptor length and version */
> + if (le16_to_cpu(desc->hid_desc_len) != sizeof(*desc) ||
> + le16_to_cpu(desc->bcd_version) != HID_VERSION) {
> + dev_err(dev, "Unsupported HID version\n");
> + return -ENODEV;
> + }
> +
> + goto exit;
> +
> +error:
> + mutex_lock(&ts->system_lock);
> + ts->hid_cmd_state = HID_CMD_DONE;
> + mutex_unlock(&ts->system_lock);
> +exit:
> + return rc;
> +}
> +
> +static int fill_tch_abs(struct cyttsp5_tch_abs_params *tch_abs, int report_size,
> + int offset)
> +{
> + tch_abs->ofs = offset / 8;
> + tch_abs->size = report_size / 8;
> + if (report_size % 8)
> + tch_abs->size += 1;
> + tch_abs->min = 0;
> + tch_abs->max = 1 << report_size;
> + tch_abs->bofs = offset - (tch_abs->ofs << 3);
> +
> + return 0;
> +}
> +
> +static int move_button_data(struct cyttsp5 *ts, struct cyttsp5_sysinfo *si)
> +{
> + memcpy(si->xy_mode, ts->input_buf, BTN_INPUT_HEADER_SIZE);
> + memcpy(si->xy_data, &ts->input_buf[BTN_INPUT_HEADER_SIZE],
> + BTN_REPORT_SIZE);
> +
> + return 0;
> +}
> +
> +static int move_touch_data(struct cyttsp5 *ts, struct cyttsp5_sysinfo *si)
> +{
> + int max_tch = si->sensing_conf_data.max_tch;
> + int num_cur_tch;
> + int length;
> + struct cyttsp5_tch_abs_params *tch = &si->tch_hdr;
> +
> + memcpy(si->xy_mode, ts->input_buf, TOUCH_INPUT_HEADER_SIZE);
> +
> + cyttsp5_get_touch_axis(&num_cur_tch, tch->size,
> + tch->max, si->xy_mode + 3 + tch->ofs, tch->bofs);
> + if (unlikely(num_cur_tch > max_tch))
> + num_cur_tch = max_tch;
> +
> + length = num_cur_tch * TOUCH_REPORT_SIZE;
> +
> + memcpy(si->xy_data, &ts->input_buf[TOUCH_INPUT_HEADER_SIZE], length);

Why do we need to do all these moves? Can we parse the date directly
from the input buffer?

> +
> + return 0;
> +}
> +
> +static irqreturn_t cyttsp5_handle_irq(int irq, void *handle)
> +{
> + struct cyttsp5 *ts = handle;
> + int report_id;
> + int size;
> + int rc;
> +
> + rc = cyttsp5_read(ts, ts->input_buf, CY_MAX_INPUT);
> + if (rc)
> + return IRQ_HANDLED;
> +
> + size = get_unaligned_le16(&ts->input_buf[0]);
> +
> + /* check reset */
> + if (size == 0) {
> + memcpy(ts->response_buf, ts->input_buf, 2);
> +
> + mutex_lock(&ts->system_lock);

Why is this lock needed exactly?

> + ts->hid_cmd_state = HID_CMD_DONE;
> + mutex_unlock(&ts->system_lock);
> + wake_up(&ts->wait_q);
> + return IRQ_HANDLED;
> + }
> +
> + report_id = ts->input_buf[2];

I'd probably do:

if (size == 0) {
/* reset */
report_id = HID_EMPTY_RESPONSE_ID; /* = 0 */
size = 2;
} else {
report_id = ts->input_buf[2];
}

> +
> + if (report_id == HID_TOUCH_REPORT_ID) {

switch (report_id) {

> + move_touch_data(ts, &ts->sysinfo);
> + cyttsp5_mt_attention(ts->dev);
> + } else if (report_id == HID_BTN_REPORT_ID) {
> + move_button_data(ts, &ts->sysinfo);
> + cyttsp5_btn_attention(ts->dev);
> + } else {
> + /* It is not an input but a command response */
> + memcpy(ts->response_buf, ts->input_buf, size);
> +
> + mutex_lock(&ts->system_lock);
> + ts->hid_cmd_state = HID_CMD_DONE;
> + mutex_unlock(&ts->system_lock);
> + wake_up(&ts->wait_q);
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int cyttsp5_deassert_int(struct cyttsp5 *ts)
> +{
> + u16 size;
> + u8 buf[2];
> + int rc;
> +
> + rc = regmap_bulk_read(ts->regmap, HID_INPUT_REG, buf, 2);
> + if (rc < 0)
> + return rc;
> +
> + size = get_unaligned_le16(&buf[0]);
> + if (size == 2 || size == 0)
> + return 0;

If you were to use level interrupts this probably would not be needed.

> +
> + return -EINVAL;
> +}
> +
> +static int cyttsp5_fill_all_touch(struct cyttsp5 *ts)
> +{
> + struct cyttsp5_sysinfo *si = &ts->sysinfo;
> +
> + fill_tch_abs(&si->tch_abs[CY_TCH_X], REPORT_SIZE_16,
> + TOUCH_REPORT_DESC_X);
> + fill_tch_abs(&si->tch_abs[CY_TCH_Y], REPORT_SIZE_16,
> + TOUCH_REPORT_DESC_Y);
> + fill_tch_abs(&si->tch_abs[CY_TCH_P], REPORT_SIZE_8,
> + TOUCH_REPORT_DESC_P);
> + fill_tch_abs(&si->tch_abs[CY_TCH_T], REPORT_SIZE_5,
> + TOUCH_REPORT_DESC_CONTACTID);
> + fill_tch_abs(&si->tch_hdr, REPORT_SIZE_5,
> + TOUCH_REPORT_DESC_HDR_CONTACTCOUNT);
> + fill_tch_abs(&si->tch_abs[CY_TCH_MAJ], REPORT_SIZE_8,
> + TOUCH_REPORT_DESC_MAJ);
> + fill_tch_abs(&si->tch_abs[CY_TCH_MIN], REPORT_SIZE_8,
> + TOUCH_REPORT_DESC_MIN);
> +
> + return 0;
> +}
> +
> +static int cyttsp5_startup(struct cyttsp5 *ts)
> +{
> + int rc;
> +
> + rc = cyttsp5_deassert_int(ts);
> + if (rc) {
> + dev_err(ts->dev, "Error on deassert int r=%d\n", rc);
> + return -ENODEV;
> + }
> +
> + /*
> + * Launch the application as the device starts in bootloader mode
> + * because of a power-on-reset
> + */
> + rc = cyttsp5_hid_output_bl_launch_app(ts);
> + if (rc < 0) {
> + dev_err(ts->dev, "Error on launch app r=%d\n", rc);
> + return rc;
> + }
> +
> + rc = cyttsp5_get_hid_descriptor(ts, &ts->hid_desc);
> + if (rc < 0) {
> + dev_err(ts->dev, "Error on getting HID descriptor r=%d\n", rc);
> + return rc;
> + }
> +
> + rc = cyttsp5_fill_all_touch(ts);
> + if (rc < 0) {
> + dev_err(ts->dev, "Error on report descriptor r=%d\n", rc);
> + return rc;
> + }
> +
> + rc = cyttsp5_hid_output_get_sysinfo(ts);
> + if (rc) {
> + dev_err(ts->dev, "Error on getting sysinfo r=%d\n", rc);
> + return rc;
> + }
> +
> + return rc;
> +}
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id cyttsp5_of_match[] = {
> + { .compatible = "cypress,tt21000", },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, cyttsp5_of_match);
> +#endif
> +
> +static const struct i2c_device_id cyttsp5_i2c_id[] = {
> + { CYTTSP5_NAME, 0, },
> + { }
> +};
> +MODULE_DEVICE_TABLE(i2c, cyttsp5_i2c_id);
> +
> +static int cyttsp5_probe(struct device *dev, struct regmap *regmap, int irq,
> + const char *name)
> +{
> + struct cyttsp5 *ts;
> + struct cyttsp5_sysinfo *si;
> + int rc = 0, i;
> +
> + ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
> + if (!ts)
> + return -ENOMEM;
> +
> + /* Initialize device info */
> + ts->regmap = regmap;
> + ts->dev = dev;
> + si = &ts->sysinfo;
> + dev_set_drvdata(dev, ts);
> +
> + /* Initialize mutexes and spinlocks */
> + mutex_init(&ts->system_lock);
> +
> + /* Initialize wait queue */
> + init_waitqueue_head(&ts->wait_q);
> +
> + /* Power up the device */
> + ts->vdd = regulator_get(dev, "vdd");

Do not mix managed an unmanaged resources. You are leaking this
regulator.

> + if (IS_ERR(ts->vdd)) {
> + rc = PTR_ERR(ts->vdd);
> + dev_set_drvdata(dev, NULL);
> + kfree(ts);
> + return rc;
> + }
> +
> + rc = regulator_enable(ts->vdd);
> + if (rc) {
> + regulator_put(ts->vdd);
> + dev_set_drvdata(dev, NULL);
> + kfree(ts);
> + return rc;
> + }
> +
> + /* Reset the gpio to be in a reset state */
> + ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
> + if (IS_ERR(ts->reset_gpio)) {
> + rc = PTR_ERR(ts->reset_gpio);
> + dev_err(dev, "Failed to request reset gpio, error %d\n", rc);
> + return rc;
> + }
> + gpiod_set_value(ts->reset_gpio, 1);
> +
> + /* Need a delay to have device up */
> + msleep(20);
> +
> + rc = devm_request_threaded_irq(dev, irq, NULL, cyttsp5_handle_irq,
> + IRQF_TRIGGER_FALLING | IRQF_ONESHOT,

Please do not override platform setup with hardcoded triggers. Also, it
is strongly recommended to use level interrupts for these peripherals.

This is also likely unsafe if controller is not completely shut off and
is capable of generating interrupts given input device is not yet
allocated.

> + name, ts);
> + if (rc) {
> + dev_err(dev, "unable to request IRQ\n");
> + return rc;
> + }
> +
> + rc = cyttsp5_startup(ts);
> + if (rc) {
> + dev_err(ts->dev, "Fail initial startup r=%d\n", rc);
> + return rc;
> + }
> +
> + rc = cyttsp5_parse_dt_key_code(dev);
> + if (rc < 0) {
> + dev_err(ts->dev, "Error while parsing dts %d\n", rc);
> + return rc;
> + }
> +
> + ts->input = devm_input_allocate_device(dev);
> + if (!ts->input) {
> + dev_err(dev, "Error, failed to allocate input device\n");
> + return -ENODEV;
> + }
> +
> + ts->input->name = "cyttsp5";
> + scnprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
> + ts->input->phys = ts->phys;
> + ts->input->dev.parent = ts->dev;

No need to do this, devm_input_allocate_device() sets up parent.

> + input_set_drvdata(ts->input, ts);
> +
> + touchscreen_parse_properties(ts->input, true, &ts->prop);
> +
> + __set_bit(EV_KEY, ts->input->evbit);
> + __set_bit(ABS_X, ts->input->absbit);
> + __set_bit(ABS_Y, ts->input->absbit);
> + __set_bit(BTN_TOUCH, ts->input->keybit);

These 3 should not be needed.

> + for (i = 0; i < si->num_btns; i++)
> + __set_bit(si->key_code[i], ts->input->keybit);
> +
> + return cyttsp5_setup_input_device(dev);
> +}
> +
> +static int cyttsp5_i2c_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct regmap *regmap;
> + static const struct regmap_config config = {
> + .reg_bits = 8,
> + .val_bits = 8,
> + };
> +
> + regmap = devm_regmap_init_i2c(client, &config);
> + if (IS_ERR(regmap)) {
> + dev_err(&client->dev, "regmap allocation failed: %ld\n",
> + PTR_ERR(regmap));
> + return PTR_ERR(regmap);
> + }
> +
> + return cyttsp5_probe(&client->dev, regmap, client->irq, client->name);
> +}
> +
> +static int cyttsp5_remove(struct device *dev)
> +{
> + struct cyttsp5 *ts = dev_get_drvdata(dev);
> +
> + input_unregister_device(ts->input);

This is not needed as input device is devm managed. This entire function
can be dropped.

> +
> + return 0;
> +}
> +
> +static int cyttsp5_i2c_remove(struct i2c_client *client)
> +{
> + struct device *dev = &client->dev;
> +
> + return cyttsp5_remove(dev);
> +}
> +
> +static struct i2c_driver cyttsp5_i2c_driver = {
> + .driver = {
> + .name = CYTTSP5_NAME,
> + .of_match_table = of_match_ptr(cyttsp5_of_match),
> + },
> + .probe = cyttsp5_i2c_probe,
> + .remove = cyttsp5_i2c_remove,
> + .id_table = cyttsp5_i2c_id,
> +};
> +
> +module_i2c_driver(cyttsp5_i2c_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("Touchscreen driver for Cypress TrueTouch Gen 5 Product");
> +MODULE_AUTHOR("Mylène Josserand <mylene.josserand@bootlin.com>");
> --
> 2.31.1
>

Thanks.

--
Dmitry