// SPDX-License-Identifier: GPL-2.0-only

  /*
   * Core Source for:
   * Cypress TrueTouch(TM) Standard Product (TTSP) touchscreen drivers.
   * For use with Cypress Txx3xx parts.
   * Supported parts include:
   * CY8CTST341
   * CY8CTMA340
   *
   * Copyright (C) 2009, 2010, 2011 Cypress Semiconductor, Inc.
   * Copyright (C) 2012 Javier Martinez Canillas <javier@dowhile0.org>
   *

   * Contact Cypress Semiconductor at www.cypress.com <kev@cypress.com>

   */
  
  #include <linux/delay.h>
  #include <linux/input.h>
  #include <linux/input/mt.h>

  #include <linux/input/touchscreen.h>

  #include <linux/gpio.h>
  #include <linux/interrupt.h>
  #include <linux/slab.h>

  #include <linux/property.h>
  #include <linux/gpio/consumer.h>

  
  #include "cyttsp_core.h"
  
  /* Bootloader number of command keys */
  #define CY_NUM_BL_KEYS		8
  
  /* helpers */
  #define GET_NUM_TOUCHES(x)		((x) & 0x0F)
  #define IS_LARGE_AREA(x)		(((x) & 0x10) >> 4)
  #define IS_BAD_PKT(x)			((x) & 0x20)
  #define IS_VALID_APP(x)			((x) & 0x01)
  #define IS_OPERATIONAL_ERR(x)		((x) & 0x3F)
  #define GET_HSTMODE(reg)		(((reg) & 0x70) >> 4)
  #define GET_BOOTLOADERMODE(reg)		(((reg) & 0x10) >> 4)
  
  #define CY_REG_BASE			0x00
  #define CY_REG_ACT_DIST			0x1E
  #define CY_REG_ACT_INTRVL		0x1D
  #define CY_REG_TCH_TMOUT		(CY_REG_ACT_INTRVL + 1)
  #define CY_REG_LP_INTRVL		(CY_REG_TCH_TMOUT + 1)
  #define CY_MAXZ				255
  #define CY_DELAY_DFLT			20 /* ms */
  #define CY_DELAY_MAX			500
  #define CY_ACT_DIST_DFLT		0xF8

  #define CY_ACT_DIST_MASK		0x0F

  #define CY_HNDSHK_BIT			0x80
  /* device mode bits */
  #define CY_OPERATE_MODE			0x00
  #define CY_SYSINFO_MODE			0x10
  /* power mode select bits */
  #define CY_SOFT_RESET_MODE		0x01 /* return to Bootloader mode */
  #define CY_DEEP_SLEEP_MODE		0x02
  #define CY_LOW_POWER_MODE		0x04
  
  /* Slots management */
  #define CY_MAX_FINGER			4
  #define CY_MAX_ID			16
  
  static const u8 bl_command[] = {
  	0x00,			/* file offset */
  	0xFF,			/* command */
  	0xA5,			/* exit bootloader command */
  	0, 1, 2, 3, 4, 5, 6, 7	/* default keys */
  };
  
  static int ttsp_read_block_data(struct cyttsp *ts, u8 command,
  				u8 length, void *buf)
  {
  	int error;
  	int tries;
  
  	for (tries = 0; tries < CY_NUM_RETRY; tries++) {

  		error = ts->bus_ops->read(ts->dev, ts->xfer_buf, command,
  				length, buf);

  		if (!error)
  			return 0;
  
  		msleep(CY_DELAY_DFLT);
  	}
  
  	return -EIO;
  }
  
  static int ttsp_write_block_data(struct cyttsp *ts, u8 command,
  				 u8 length, void *buf)
  {
  	int error;
  	int tries;
  
  	for (tries = 0; tries < CY_NUM_RETRY; tries++) {

  		error = ts->bus_ops->write(ts->dev, ts->xfer_buf, command,
  				length, buf);

  		if (!error)
  			return 0;
  
  		msleep(CY_DELAY_DFLT);
  	}
  
  	return -EIO;
  }
  
  static int ttsp_send_command(struct cyttsp *ts, u8 cmd)
  {
  	return ttsp_write_block_data(ts, CY_REG_BASE, sizeof(cmd), &cmd);
  }

  static int cyttsp_handshake(struct cyttsp *ts)
  {

  	if (ts->use_hndshk)

  		return ttsp_send_command(ts,
  				ts->xy_data.hst_mode ^ CY_HNDSHK_BIT);
  
  	return 0;
  }

  static int cyttsp_load_bl_regs(struct cyttsp *ts)
  {
  	memset(&ts->bl_data, 0, sizeof(ts->bl_data));
  	ts->bl_data.bl_status = 0x10;
  
  	return ttsp_read_block_data(ts, CY_REG_BASE,
  				    sizeof(ts->bl_data), &ts->bl_data);
  }
  
  static int cyttsp_exit_bl_mode(struct cyttsp *ts)
  {
  	int error;
  	u8 bl_cmd[sizeof(bl_command)];
  
  	memcpy(bl_cmd, bl_command, sizeof(bl_command));

  	if (ts->bl_keys)

  		memcpy(&bl_cmd[sizeof(bl_command) - CY_NUM_BL_KEYS],

  			ts->bl_keys, CY_NUM_BL_KEYS);

  
  	error = ttsp_write_block_data(ts, CY_REG_BASE,
  				      sizeof(bl_cmd), bl_cmd);
  	if (error)
  		return error;
  
  	/* wait for TTSP Device to complete the operation */
  	msleep(CY_DELAY_DFLT);
  
  	error = cyttsp_load_bl_regs(ts);
  	if (error)
  		return error;
  
  	if (GET_BOOTLOADERMODE(ts->bl_data.bl_status))
  		return -EIO;
  
  	return 0;
  }
  
  static int cyttsp_set_operational_mode(struct cyttsp *ts)
  {
  	int error;
  
  	error = ttsp_send_command(ts, CY_OPERATE_MODE);
  	if (error)
  		return error;
  
  	/* wait for TTSP Device to complete switch to Operational mode */
  	error = ttsp_read_block_data(ts, CY_REG_BASE,
  				     sizeof(ts->xy_data), &ts->xy_data);
  	if (error)
  		return error;

  	error = cyttsp_handshake(ts);
  	if (error)
  		return error;

  	return ts->xy_data.act_dist == CY_ACT_DIST_DFLT ? -EIO : 0;
  }
  
  static int cyttsp_set_sysinfo_mode(struct cyttsp *ts)
  {
  	int error;
  
  	memset(&ts->sysinfo_data, 0, sizeof(ts->sysinfo_data));
  
  	/* switch to sysinfo mode */
  	error = ttsp_send_command(ts, CY_SYSINFO_MODE);
  	if (error)
  		return error;
  
  	/* read sysinfo registers */
  	msleep(CY_DELAY_DFLT);
  	error = ttsp_read_block_data(ts, CY_REG_BASE, sizeof(ts->sysinfo_data),
  				      &ts->sysinfo_data);
  	if (error)
  		return error;

  	error = cyttsp_handshake(ts);
  	if (error)
  		return error;

  	if (!ts->sysinfo_data.tts_verh && !ts->sysinfo_data.tts_verl)
  		return -EIO;
  
  	return 0;
  }
  
  static int cyttsp_set_sysinfo_regs(struct cyttsp *ts)
  {
  	int retval = 0;

  	if (ts->act_intrvl != CY_ACT_INTRVL_DFLT ||
  	    ts->tch_tmout != CY_TCH_TMOUT_DFLT ||
  	    ts->lp_intrvl != CY_LP_INTRVL_DFLT) {

  
  		u8 intrvl_ray[] = {

  			ts->act_intrvl,
  			ts->tch_tmout,
  			ts->lp_intrvl

  		};
  
  		/* set intrvl registers */
  		retval = ttsp_write_block_data(ts, CY_REG_ACT_INTRVL,
  					sizeof(intrvl_ray), intrvl_ray);
  		msleep(CY_DELAY_DFLT);
  	}
  
  	return retval;
  }

  static void cyttsp_hard_reset(struct cyttsp *ts)
  {
  	if (ts->reset_gpio) {
  		gpiod_set_value_cansleep(ts->reset_gpio, 1);
  		msleep(CY_DELAY_DFLT);
  		gpiod_set_value_cansleep(ts->reset_gpio, 0);
  		msleep(CY_DELAY_DFLT);
  	}
  }

  static int cyttsp_soft_reset(struct cyttsp *ts)
  {
  	unsigned long timeout;
  	int retval;
  
  	/* wait for interrupt to set ready completion */

  	reinit_completion(&ts->bl_ready);

  	ts->state = CY_BL_STATE;
  
  	enable_irq(ts->irq);
  
  	retval = ttsp_send_command(ts, CY_SOFT_RESET_MODE);
  	if (retval)
  		goto out;
  
  	timeout = wait_for_completion_timeout(&ts->bl_ready,
  			msecs_to_jiffies(CY_DELAY_DFLT * CY_DELAY_MAX));
  	retval = timeout ? 0 : -EIO;
  
  out:
  	ts->state = CY_IDLE_STATE;
  	disable_irq(ts->irq);
  	return retval;
  }
  
  static int cyttsp_act_dist_setup(struct cyttsp *ts)
  {

  	u8 act_dist_setup = ts->act_dist;

  
  	/* Init gesture; active distance setup */
  	return ttsp_write_block_data(ts, CY_REG_ACT_DIST,
  				sizeof(act_dist_setup), &act_dist_setup);
  }
  
  static void cyttsp_extract_track_ids(struct cyttsp_xydata *xy_data, int *ids)
  {
  	ids[0] = xy_data->touch12_id >> 4;
  	ids[1] = xy_data->touch12_id & 0xF;
  	ids[2] = xy_data->touch34_id >> 4;
  	ids[3] = xy_data->touch34_id & 0xF;
  }
  
  static const struct cyttsp_tch *cyttsp_get_tch(struct cyttsp_xydata *xy_data,
  					       int idx)
  {
  	switch (idx) {
  	case 0:
  		return &xy_data->tch1;
  	case 1:
  		return &xy_data->tch2;
  	case 2:
  		return &xy_data->tch3;
  	case 3:
  		return &xy_data->tch4;
  	default:
  		return NULL;
  	}
  }
  
  static void cyttsp_report_tchdata(struct cyttsp *ts)
  {
  	struct cyttsp_xydata *xy_data = &ts->xy_data;
  	struct input_dev *input = ts->input;
  	int num_tch = GET_NUM_TOUCHES(xy_data->tt_stat);
  	const struct cyttsp_tch *tch;
  	int ids[CY_MAX_ID];
  	int i;
  	DECLARE_BITMAP(used, CY_MAX_ID);
  
  	if (IS_LARGE_AREA(xy_data->tt_stat) == 1) {
  		/* terminate all active tracks */
  		num_tch = 0;
  		dev_dbg(ts->dev, "%s: Large area detected
  ", __func__);
  	} else if (num_tch > CY_MAX_FINGER) {
  		/* terminate all active tracks */
  		num_tch = 0;
  		dev_dbg(ts->dev, "%s: Num touch error detected
  ", __func__);
  	} else if (IS_BAD_PKT(xy_data->tt_mode)) {
  		/* terminate all active tracks */
  		num_tch = 0;
  		dev_dbg(ts->dev, "%s: Invalid buffer detected
  ", __func__);
  	}
  
  	cyttsp_extract_track_ids(xy_data, ids);
  
  	bitmap_zero(used, CY_MAX_ID);
  
  	for (i = 0; i < num_tch; i++) {
  		tch = cyttsp_get_tch(xy_data, i);
  
  		input_mt_slot(input, ids[i]);
  		input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
  		input_report_abs(input, ABS_MT_POSITION_X, be16_to_cpu(tch->x));
  		input_report_abs(input, ABS_MT_POSITION_Y, be16_to_cpu(tch->y));
  		input_report_abs(input, ABS_MT_TOUCH_MAJOR, tch->z);
  
  		__set_bit(ids[i], used);
  	}
  
  	for (i = 0; i < CY_MAX_ID; i++) {
  		if (test_bit(i, used))
  			continue;
  
  		input_mt_slot(input, i);
  		input_mt_report_slot_state(input, MT_TOOL_FINGER, false);
  	}
  
  	input_sync(input);
  }
  
  static irqreturn_t cyttsp_irq(int irq, void *handle)
  {
  	struct cyttsp *ts = handle;
  	int error;
  
  	if (unlikely(ts->state == CY_BL_STATE)) {
  		complete(&ts->bl_ready);
  		goto out;
  	}
  
  	/* Get touch data from CYTTSP device */
  	error = ttsp_read_block_data(ts, CY_REG_BASE,
  				 sizeof(struct cyttsp_xydata), &ts->xy_data);
  	if (error)
  		goto out;
  
  	/* provide flow control handshake */

  	error = cyttsp_handshake(ts);
  	if (error)
  		goto out;

  
  	if (unlikely(ts->state == CY_IDLE_STATE))
  		goto out;
  
  	if (GET_BOOTLOADERMODE(ts->xy_data.tt_mode)) {
  		/*
  		 * TTSP device has reset back to bootloader mode.
  		 * Restore to operational mode.
  		 */
  		error = cyttsp_exit_bl_mode(ts);
  		if (error) {
  			dev_err(ts->dev,
  				"Could not return to operational mode, err: %d
  ",
  				error);
  			ts->state = CY_IDLE_STATE;
  		}
  	} else {
  		cyttsp_report_tchdata(ts);
  	}
  
  out:
  	return IRQ_HANDLED;
  }
  
  static int cyttsp_power_on(struct cyttsp *ts)
  {
  	int error;
  
  	error = cyttsp_soft_reset(ts);
  	if (error)
  		return error;
  
  	error = cyttsp_load_bl_regs(ts);
  	if (error)
  		return error;
  
  	if (GET_BOOTLOADERMODE(ts->bl_data.bl_status) &&
  	    IS_VALID_APP(ts->bl_data.bl_status)) {
  		error = cyttsp_exit_bl_mode(ts);
  		if (error)
  			return error;
  	}
  
  	if (GET_HSTMODE(ts->bl_data.bl_file) != CY_OPERATE_MODE ||
  	    IS_OPERATIONAL_ERR(ts->bl_data.bl_status)) {
  		return -ENODEV;
  	}
  
  	error = cyttsp_set_sysinfo_mode(ts);
  	if (error)
  		return error;
  
  	error = cyttsp_set_sysinfo_regs(ts);
  	if (error)
  		return error;
  
  	error = cyttsp_set_operational_mode(ts);
  	if (error)
  		return error;
  
  	/* init active distance */
  	error = cyttsp_act_dist_setup(ts);
  	if (error)
  		return error;
  
  	ts->state = CY_ACTIVE_STATE;
  
  	return 0;
  }
  
  static int cyttsp_enable(struct cyttsp *ts)
  {
  	int error;
  
  	/*
  	 * The device firmware can wake on an I2C or SPI memory slave
  	 * address match. So just reading a register is sufficient to
  	 * wake up the device. The first read attempt will fail but it
  	 * will wake it up making the second read attempt successful.
  	 */
  	error = ttsp_read_block_data(ts, CY_REG_BASE,
  				     sizeof(ts->xy_data), &ts->xy_data);
  	if (error)
  		return error;
  
  	if (GET_HSTMODE(ts->xy_data.hst_mode))
  		return -EIO;
  
  	enable_irq(ts->irq);
  
  	return 0;
  }
  
  static int cyttsp_disable(struct cyttsp *ts)
  {
  	int error;
  
  	error = ttsp_send_command(ts, CY_LOW_POWER_MODE);
  	if (error)
  		return error;
  
  	disable_irq(ts->irq);
  
  	return 0;
  }

  static int __maybe_unused cyttsp_suspend(struct device *dev)

  {
  	struct cyttsp *ts = dev_get_drvdata(dev);
  	int retval = 0;
  
  	mutex_lock(&ts->input->mutex);
  
  	if (ts->input->users) {
  		retval = cyttsp_disable(ts);
  		if (retval == 0)
  			ts->suspended = true;
  	}
  
  	mutex_unlock(&ts->input->mutex);
  
  	return retval;
  }

  static int __maybe_unused cyttsp_resume(struct device *dev)

  {
  	struct cyttsp *ts = dev_get_drvdata(dev);
  
  	mutex_lock(&ts->input->mutex);
  
  	if (ts->input->users)
  		cyttsp_enable(ts);
  
  	ts->suspended = false;
  
  	mutex_unlock(&ts->input->mutex);
  
  	return 0;
  }

  SIMPLE_DEV_PM_OPS(cyttsp_pm_ops, cyttsp_suspend, cyttsp_resume);
  EXPORT_SYMBOL_GPL(cyttsp_pm_ops);
  
  static int cyttsp_open(struct input_dev *dev)
  {
  	struct cyttsp *ts = input_get_drvdata(dev);
  	int retval = 0;
  
  	if (!ts->suspended)
  		retval = cyttsp_enable(ts);
  
  	return retval;
  }
  
  static void cyttsp_close(struct input_dev *dev)
  {
  	struct cyttsp *ts = input_get_drvdata(dev);
  
  	if (!ts->suspended)
  		cyttsp_disable(ts);
  }

  static int cyttsp_parse_properties(struct cyttsp *ts)

  {

  	struct device *dev = ts->dev;
  	u32 dt_value;
  	int ret;
  
  	ts->bl_keys = devm_kzalloc(dev, CY_NUM_BL_KEYS, GFP_KERNEL);
  	if (!ts->bl_keys)
  		return -ENOMEM;
  
  	/* Set some default values */
  	ts->use_hndshk = false;
  	ts->act_dist = CY_ACT_DIST_DFLT;
  	ts->act_intrvl = CY_ACT_INTRVL_DFLT;
  	ts->tch_tmout = CY_TCH_TMOUT_DFLT;
  	ts->lp_intrvl = CY_LP_INTRVL_DFLT;
  
  	ret = device_property_read_u8_array(dev, "bootloader-key",
  					    ts->bl_keys, CY_NUM_BL_KEYS);
  	if (ret) {
  		dev_err(dev,
  			"bootloader-key property could not be retrieved
  ");
  		return ret;
  	}
  
  	ts->use_hndshk = device_property_present(dev, "use-handshake");
  
  	if (!device_property_read_u32(dev, "active-distance", &dt_value)) {
  		if (dt_value > 15) {
  			dev_err(dev, "active-distance (%u) must be [0-15]
  ",
  				dt_value);
  			return -EINVAL;
  		}
  		ts->act_dist &= ~CY_ACT_DIST_MASK;
  		ts->act_dist |= dt_value;
  	}
  
  	if (!device_property_read_u32(dev, "active-interval-ms", &dt_value)) {
  		if (dt_value > 255) {
  			dev_err(dev, "active-interval-ms (%u) must be [0-255]
  ",
  				dt_value);
  			return -EINVAL;
  		}
  		ts->act_intrvl = dt_value;
  	}

  	if (!device_property_read_u32(dev, "lowpower-interval-ms", &dt_value)) {
  		if (dt_value > 2550) {
  			dev_err(dev, "lowpower-interval-ms (%u) must be [0-2550]
  ",
  				dt_value);
  			return -EINVAL;
  		}
  		/* Register value is expressed in 0.01s / bit */
  		ts->lp_intrvl = dt_value / 10;
  	}
  
  	if (!device_property_read_u32(dev, "touch-timeout-ms", &dt_value)) {
  		if (dt_value > 2550) {
  			dev_err(dev, "touch-timeout-ms (%u) must be [0-2550]
  ",
  				dt_value);
  			return -EINVAL;
  		}
  		/* Register value is expressed in 0.01s / bit */
  		ts->tch_tmout = dt_value / 10;
  	}
  
  	return 0;

  }

  struct cyttsp *cyttsp_probe(const struct cyttsp_bus_ops *bus_ops,
  			    struct device *dev, int irq, size_t xfer_buf_size)
  {

  	struct cyttsp *ts;
  	struct input_dev *input_dev;
  	int error;

  	ts = devm_kzalloc(dev, sizeof(*ts) + xfer_buf_size, GFP_KERNEL);
  	if (!ts)
  		return ERR_PTR(-ENOMEM);
  
  	input_dev = devm_input_allocate_device(dev);
  	if (!input_dev)
  		return ERR_PTR(-ENOMEM);

  
  	ts->dev = dev;
  	ts->input = input_dev;

  	ts->bus_ops = bus_ops;
  	ts->irq = irq;

  	ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
  	if (IS_ERR(ts->reset_gpio)) {
  		error = PTR_ERR(ts->reset_gpio);
  		dev_err(dev, "Failed to request reset gpio, error %d
  ", error);

  		return ERR_PTR(error);
  	}

  	error = cyttsp_parse_properties(ts);
  	if (error)
  		return ERR_PTR(error);
  
  	init_completion(&ts->bl_ready);
  	snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));

  	input_dev->name = "Cypress TTSP TouchScreen";

  	input_dev->phys = ts->phys;
  	input_dev->id.bustype = bus_ops->bustype;
  	input_dev->dev.parent = ts->dev;
  
  	input_dev->open = cyttsp_open;
  	input_dev->close = cyttsp_close;
  
  	input_set_drvdata(input_dev, ts);

  	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X);
  	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y);

  	touchscreen_parse_properties(input_dev, true, NULL);

  	error = input_mt_init_slots(input_dev, CY_MAX_ID, 0);
  	if (error) {
  		dev_err(dev, "Unable to init MT slots.
  ");
  		return ERR_PTR(error);
  	}

  	error = devm_request_threaded_irq(dev, ts->irq, NULL, cyttsp_irq,
  					  IRQF_TRIGGER_FALLING | IRQF_ONESHOT,

  					  "cyttsp", ts);

  	if (error) {
  		dev_err(ts->dev, "failed to request IRQ %d, err: %d
  ",
  			ts->irq, error);

  		return ERR_PTR(error);

  	}
  
  	disable_irq(ts->irq);

  	cyttsp_hard_reset(ts);

  	error = cyttsp_power_on(ts);
  	if (error)

  		return ERR_PTR(error);

  
  	error = input_register_device(input_dev);
  	if (error) {
  		dev_err(ts->dev, "failed to register input device: %d
  ",
  			error);

  		return ERR_PTR(error);

  	}
  
  	return ts;

  }
  EXPORT_SYMBOL_GPL(cyttsp_probe);

  MODULE_LICENSE("GPL");
  MODULE_DESCRIPTION("Cypress TrueTouch(R) Standard touchscreen driver core");
  MODULE_AUTHOR("Cypress");