[PATCH v4 1/2] Input: Add driver for Cypress Generation 5 touchscreen

["Mylène Josserand" <mylene.josserand@free-electrons.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@free-electrons.com>
Signed-off-by: Mylène Josserand <mylene.josserand@free-electrons.com>
---
 drivers/input/touchscreen/Kconfig   |   16 +
 drivers/input/touchscreen/Makefile  |    1 +
 drivers/input/touchscreen/cyttsp5.c | 1110 +++++++++++++++++++++++++++++++++++
 3 files changed, 1127 insertions(+)
 create mode 100644 drivers/input/touchscreen/cyttsp5.c

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 0cfdb7cb610e..28eea6d5f1bb 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -238,6 +238,22 @@ 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
+	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 d2a2b3b7af27..e7d124901dd9 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -26,6 +26,7 @@ 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..a41feea2cd5a
--- /dev/null
+++ b/drivers/input/touchscreen/cyttsp5.c
@@ -0,0 +1,1110 @@
+/*
+ * Parade TrueTouch(TM) Standard Product V5 Module.
+ * For use with Parade touchscreen controllers.
+ *
+ * Copyright (C) 2015 Parade Technologies
+ * Copyright (C) 2012-2015 Cypress Semiconductor
+ * Copyright (C) 2017 Free Electrons
+ *
+ * Author: Mylène Josserand <mylene.josserand@free-electrons.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2, and only version 2, as published by the
+ * Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#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_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
+
+/* 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_DONE, HID_CMD_BUSY } hid_cmd_state;
+
+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;
+	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;
+};
+
+/*
+ * 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;
+	u32 size;
+	u8 temp[2];
+
+	if (!buf)
+		return -EINVAL;
+
+	/* Read the frame to retrieve the size */
+	rc = regmap_bulk_read(ts->regmap, HID_INPUT_REG, temp, 2);
+	if (rc < 0)
+		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[size + 1];
+
+	/* 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;
+	int next;
+
+	for (nbyte = 0, *axis = 0, next = 0; nbyte < size; nbyte++)
+		*axis = *axis + ((xy_data[nbyte] >> bofs) << (nbyte * 8));
+
+	*axis &= max - 1;
+}
+
+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);
+	}
+}
+
+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, si->tch_abs[CY_TCH_T].max);
+	u8 *tch_addr;
+	int tmp;
+
+	bitmap_zero(ids, si->tch_abs[CY_TCH_T].max);
+	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]);
+	}
+
+	cyttsp5_final_sync(ts->input, si->tch_abs[CY_TCH_T].max, ids);
+
+	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,
+			       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);
+
+	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;
+
+	/* 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);
+	__set_bit(EV_REL, ts->input->evbit);
+	__set_bit(EV_KEY, ts->input->evbit);
+
+	max_x_tmp = si->sensing_conf_data.res_x;
+	max_y_tmp = si->sensing_conf_data.res_y;
+	max_x = max_y_tmp - 1;
+	max_y = max_x_tmp - 1;
+	max_p = si->sensing_conf_data.max_z;
+
+	input_mt_init_slots(ts->input, si->tch_abs[CY_TCH_T].max, 0);
+
+	__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);
+
+	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);
+}
+#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;
+}
+
+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];
+
+	if (offset == HID_BL_RESPONSE_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++;
+	}
+}
+
+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);
+	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;
+
+	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);
+
+	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);
+		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];
+
+	if (report_id == HID_TOUCH_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;
+
+	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,cyttsp5", },
+	{ }
+};
+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);
+
+	/* 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,
+				       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;
+	input_set_drvdata(ts->input, ts);
+
+	touchscreen_parse_properties(ts->input, true, NULL);
+
+	__set_bit(EV_KEY, ts->input->evbit);
+	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);
+
+	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,
+		.owner = THIS_MODULE,
+		.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@free-electrons.com>");
-- 
2.11.0