text: /* -------------------------------------------------------------------------
   * Copyright (C) 2014-2015, Intel Corporation
   *
   * Derived from:
   *  gslX68X.c
   *  Copyright (C) 2010-2015, Shanghai Sileadinc Co.Ltd
   *
   *  This program is free software; you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License as published by
   *  the Free Software Foundation; either version 2 of the License, or
   *  (at your option) any later version.
   *
   *  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 <linux/i2c.h>
  #include <linux/module.h>
  #include <linux/acpi.h>
  #include <linux/interrupt.h>
  #include <linux/gpio/consumer.h>
  #include <linux/delay.h>
  #include <linux/firmware.h>
  #include <linux/input.h>
  #include <linux/input/mt.h>
  #include <linux/input/touchscreen.h>
  #include <linux/pm.h>
  #include <linux/irq.h>
  #include <linux/regulator/consumer.h>
  
  #include <asm/unaligned.h>
  
  #define SILEAD_TS_NAME		"silead_ts"
  
  #define SILEAD_REG_RESET	0xE0
  #define SILEAD_REG_DATA		0x80
  #define SILEAD_REG_TOUCH_NR	0x80
  #define SILEAD_REG_POWER	0xBC
  #define SILEAD_REG_CLOCK	0xE4
  #define SILEAD_REG_STATUS	0xB0
  #define SILEAD_REG_ID		0xFC
  #define SILEAD_REG_MEM_CHECK	0xB0
  
  #define SILEAD_STATUS_OK	0x5A5A5A5A
  #define SILEAD_TS_DATA_LEN	44
  #define SILEAD_CLOCK		0x04
  
  #define SILEAD_CMD_RESET	0x88
  #define SILEAD_CMD_START	0x00
  
  #define SILEAD_POINT_DATA_LEN	0x04
  #define SILEAD_POINT_Y_OFF      0x00
  #define SILEAD_POINT_Y_MSB_OFF	0x01
  #define SILEAD_POINT_X_OFF	0x02
  #define SILEAD_POINT_X_MSB_OFF	0x03
  #define SILEAD_EXTRA_DATA_MASK	0xF0
  
  #define SILEAD_CMD_SLEEP_MIN	10000
  #define SILEAD_CMD_SLEEP_MAX	20000
  #define SILEAD_POWER_SLEEP	20
  #define SILEAD_STARTUP_SLEEP	30
  
  #define SILEAD_MAX_FINGERS	10
  
  enum silead_ts_power {
  	SILEAD_POWER_ON  = 1,
  	SILEAD_POWER_OFF = 0
  };
  
  struct silead_ts_data {
  	struct i2c_client *client;
  	struct gpio_desc *gpio_power;
  	struct input_dev *input;
  	struct regulator_bulk_data regulators[2];
  	char fw_name[64];
  	struct touchscreen_properties prop;
  	u32 max_fingers;
  	u32 chip_id;
  	struct input_mt_pos pos[SILEAD_MAX_FINGERS];
  	int slots[SILEAD_MAX_FINGERS];
  	int id[SILEAD_MAX_FINGERS];
  };
  
  struct silead_fw_data {
  	u32 offset;
  	u32 val;
  };
  
  static int silead_ts_request_input_dev(struct silead_ts_data *data)
  {
  	struct device *dev = &data->client->dev;
  	int error;
  
  	data->input = devm_input_allocate_device(dev);
  	if (!data->input) {
  		dev_err(dev,
  			"Failed to allocate input device\n");
  		return -ENOMEM;
  	}
  
  	input_set_abs_params(data->input, ABS_MT_POSITION_X, 0, 4095, 0, 0);
  	input_set_abs_params(data->input, ABS_MT_POSITION_Y, 0, 4095, 0, 0);
  	touchscreen_parse_properties(data->input, true, &data->prop);
  
  	input_mt_init_slots(data->input, data->max_fingers,
  			    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED |
  			    INPUT_MT_TRACK);
  
  	if (device_property_read_bool(dev, "silead,home-button"))
  		input_set_capability(data->input, EV_KEY, KEY_LEFTMETA);
  
  	data->input->name = SILEAD_TS_NAME;
  	data->input->phys = "input/ts";
  	data->input->id.bustype = BUS_I2C;
  
  	error = input_register_device(data->input);
  	if (error) {
  		dev_err(dev, "Failed to register input device: %d\n", error);
  		return error;
  	}
  
  	return 0;
  }
  
  static void silead_ts_set_power(struct i2c_client *client,
  				enum silead_ts_power state)
  {
  	struct silead_ts_data *data = i2c_get_clientdata(client);
  
  	if (data->gpio_power) {
  		gpiod_set_value_cansleep(data->gpio_power, state);
  		msleep(SILEAD_POWER_SLEEP);
  	}
  }
  
  static void silead_ts_read_data(struct i2c_client *client)
  {
  	struct silead_ts_data *data = i2c_get_clientdata(client);
  	struct input_dev *input = data->input;
  	struct device *dev = &client->dev;
  	u8 *bufp, buf[SILEAD_TS_DATA_LEN];
  	int touch_nr, softbutton, error, i;
  	bool softbutton_pressed = false;
  
  	error = i2c_smbus_read_i2c_block_data(client, SILEAD_REG_DATA,
  					      SILEAD_TS_DATA_LEN, buf);
  	if (error < 0) {
  		dev_err(dev, "Data read error %d\n", error);
  		return;
  	}
  
  	if (buf[0] > data->max_fingers) {
  		dev_warn(dev, "More touches reported then supported %d > %d\n",
  			 buf[0], data->max_fingers);
  		buf[0] = data->max_fingers;
  	}
  
  	touch_nr = 0;
  	bufp = buf + SILEAD_POINT_DATA_LEN;
  	for (i = 0; i < buf[0]; i++, bufp += SILEAD_POINT_DATA_LEN) {
  		softbutton = (bufp[SILEAD_POINT_Y_MSB_OFF] &
  			      SILEAD_EXTRA_DATA_MASK) >> 4;
  
  		if (softbutton) {
  			/*
  			 * For now only respond to softbutton == 0x01, some
  			 * tablets *without* a capacative button send 0x04
  			 * when crossing the edges of the screen.
  			 */
  			if (softbutton == 0x01)
  				softbutton_pressed = true;
  
  			continue;
  		}
  
  		/*
  		 * Bits 4-7 are the touch id, note not all models have
  		 * hardware touch ids so atm we don't use these.
  		 */
  		data->id[touch_nr] = (bufp[SILEAD_POINT_X_MSB_OFF] &
  				      SILEAD_EXTRA_DATA_MASK) >> 4;
  		touchscreen_set_mt_pos(&data->pos[touch_nr], &data->prop,
  			get_unaligned_le16(&bufp[SILEAD_POINT_X_OFF]) & 0xfff,
  			get_unaligned_le16(&bufp[SILEAD_POINT_Y_OFF]) & 0xfff);
  		touch_nr++;
  	}
  
  	input_mt_assign_slots(input, data->slots, data->pos, touch_nr, 0);
  
  	for (i = 0; i < touch_nr; i++) {
  		input_mt_slot(input, data->slots[i]);
  		input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
  		input_report_abs(input, ABS_MT_POSITION_X, data->pos[i].x);
  		input_report_abs(input, ABS_MT_POSITION_Y, data->pos[i].y);
  
  		dev_dbg(dev, "x=%d y=%d hw_id=%d sw_id=%d\n", data->pos[i].x,
  			data->pos[i].y, data->id[i], data->slots[i]);
  	}
  
  	input_mt_sync_frame(input);
  	input_report_key(input, KEY_LEFTMETA, softbutton_pressed);
  	input_sync(input);
  }
  
  static int silead_ts_init(struct i2c_client *client)
  {
  	struct silead_ts_data *data = i2c_get_clientdata(client);
  	int error;
  
  	error = i2c_smbus_write_byte_data(client, SILEAD_REG_RESET,
  					  SILEAD_CMD_RESET);
  	if (error)
  		goto i2c_write_err;
  	usleep_range(SILEAD_CMD_SLEEP_MIN, SILEAD_CMD_SLEEP_MAX);
  
  	error = i2c_smbus_write_byte_data(client, SILEAD_REG_TOUCH_NR,
  					data->max_fingers);
  	if (error)
  		goto i2c_write_err;
  	usleep_range(SILEAD_CMD_SLEEP_MIN, SILEAD_CMD_SLEEP_MAX);
  
  	error = i2c_smbus_write_byte_data(client, SILEAD_REG_CLOCK,
  					  SILEAD_CLOCK);
  	if (error)
  		goto i2c_write_err;
  	usleep_range(SILEAD_CMD_SLEEP_MIN, SILEAD_CMD_SLEEP_MAX);
  
  	error = i2c_smbus_write_byte_data(client, SILEAD_REG_RESET,
  					  SILEAD_CMD_START);
  	if (error)
  		goto i2c_write_err;
  	usleep_range(SILEAD_CMD_SLEEP_MIN, SILEAD_CMD_SLEEP_MAX);
  
  	return 0;
  
  i2c_write_err:
  	dev_err(&client->dev, "Registers clear error %d\n", error);
  	return error;
  }
  
  static int silead_ts_reset(struct i2c_client *client)
  {
  	int error;
  
  	error = i2c_smbus_write_byte_data(client, SILEAD_REG_RESET,
  					  SILEAD_CMD_RESET);
  	if (error)
  		goto i2c_write_err;
  	usleep_range(SILEAD_CMD_SLEEP_MIN, SILEAD_CMD_SLEEP_MAX);
  
  	error = i2c_smbus_write_byte_data(client, SILEAD_REG_CLOCK,
  					  SILEAD_CLOCK);
  	if (error)
  		goto i2c_write_err;
  	usleep_range(SILEAD_CMD_SLEEP_MIN, SILEAD_CMD_SLEEP_MAX);
  
  	error = i2c_smbus_write_byte_data(client, SILEAD_REG_POWER,
  					  SILEAD_CMD_START);
  	if (error)
  		goto i2c_write_err;
  	usleep_range(SILEAD_CMD_SLEEP_MIN, SILEAD_CMD_SLEEP_MAX);
  
  	return 0;
  
  i2c_write_err:
  	dev_err(&client->dev, "Chip reset error %d\n", error);
  	return error;
  }
  
  static int silead_ts_startup(struct i2c_client *client)
  {
  	int error;
  
  	error = i2c_smbus_write_byte_data(client, SILEAD_REG_RESET, 0x00);
  	if (error) {
  		dev_err(&client->dev, "Startup error %d\n", error);
  		return error;
  	}
  
  	msleep(SILEAD_STARTUP_SLEEP);
  
  	return 0;
  }
  
  static int silead_ts_load_fw(struct i2c_client *client)
  {
  	struct device *dev = &client->dev;
  	struct silead_ts_data *data = i2c_get_clientdata(client);
  	unsigned int fw_size, i;
  	const struct firmware *fw;
  	struct silead_fw_data *fw_data;
  	int error;
  
  	dev_dbg(dev, "Firmware file name: %s", data->fw_name);
  
  	error = request_firmware(&fw, data->fw_name, dev);
  	if (error) {
  		dev_err(dev, "Firmware request error %d\n", error);
  		return error;
  	}
  
  	fw_size = fw->size / sizeof(*fw_data);
  	fw_data = (struct silead_fw_data *)fw->data;
  
  	for (i = 0; i < fw_size; i++) {
  		error = i2c_smbus_write_i2c_block_data(client,
  						       fw_data[i].offset,
  						       4,
  						       (u8 *)&fw_data[i].val);
  		if (error) {
  			dev_err(dev, "Firmware load error %d\n", error);
  			break;
  		}
  	}
  
  	release_firmware(fw);
  	return error ?: 0;
  }
  
  static u32 silead_ts_get_status(struct i2c_client *client)
  {
  	int error;
  	__le32 status;
  
  	error = i2c_smbus_read_i2c_block_data(client, SILEAD_REG_STATUS,
  					      sizeof(status), (u8 *)&status);
  	if (error < 0) {
  		dev_err(&client->dev, "Status read error %d\n", error);
  		return error;
  	}
  
  	return le32_to_cpu(status);
  }
  
  static int silead_ts_get_id(struct i2c_client *client)
  {
  	struct silead_ts_data *data = i2c_get_clientdata(client);
  	__le32 chip_id;
  	int error;
  
  	error = i2c_smbus_read_i2c_block_data(client, SILEAD_REG_ID,
  					      sizeof(chip_id), (u8 *)&chip_id);
  	if (error < 0) {
  		dev_err(&client->dev, "Chip ID read error %d\n", error);
  		return error;
  	}
  
  	data->chip_id = le32_to_cpu(chip_id);
  	dev_info(&client->dev, "Silead chip ID: 0x%8X", data->chip_id);
  
  	return 0;
  }
  
  static int silead_ts_setup(struct i2c_client *client)
  {
  	int error;
  	u32 status;
  
  	silead_ts_set_power(client, SILEAD_POWER_OFF);
  	silead_ts_set_power(client, SILEAD_POWER_ON);
  
  	error = silead_ts_get_id(client);
  	if (error)
  		return error;
  
  	error = silead_ts_init(client);
  	if (error)
  		return error;
  
  	error = silead_ts_reset(client);
  	if (error)
  		return error;
  
  	error = silead_ts_load_fw(client);
  	if (error)
  		return error;
  
  	error = silead_ts_startup(client);
  	if (error)
  		return error;
  
  	status = silead_ts_get_status(client);
  	if (status != SILEAD_STATUS_OK) {
  		dev_err(&client->dev,
  			"Initialization error, status: 0x%X\n", status);
  		return -ENODEV;
  	}
  
  	return 0;
  }
  
  static irqreturn_t silead_ts_threaded_irq_handler(int irq, void *id)
  {
  	struct silead_ts_data *data = id;
  	struct i2c_client *client = data->client;
  
  	silead_ts_read_data(client);
  
  	return IRQ_HANDLED;
  }
  
  static void silead_ts_read_props(struct i2c_client *client)
  {
  	struct silead_ts_data *data = i2c_get_clientdata(client);
  	struct device *dev = &client->dev;
  	const char *str;
  	int error;
  
  	error = device_property_read_u32(dev, "silead,max-fingers",
  					 &data->max_fingers);
  	if (error) {
  		dev_dbg(dev, "Max fingers read error %d\n", error);
  		data->max_fingers = 5; /* Most devices handle up-to 5 fingers */
  	}
  
  	error = device_property_read_string(dev, "firmware-name", &str);
  	if (!error)
  		snprintf(data->fw_name, sizeof(data->fw_name),
  			 "silead/%s", str);
  	else
  		dev_dbg(dev, "Firmware file name read error. Using default.");
  }
  
  #ifdef CONFIG_ACPI
  static int silead_ts_set_default_fw_name(struct silead_ts_data *data,
  					 const struct i2c_device_id *id)
  {
  	const struct acpi_device_id *acpi_id;
  	struct device *dev = &data->client->dev;
  	int i;
  
  	if (ACPI_HANDLE(dev)) {
  		acpi_id = acpi_match_device(dev->driver->acpi_match_table, dev);
  		if (!acpi_id)
  			return -ENODEV;
  
  		snprintf(data->fw_name, sizeof(data->fw_name),
  			 "silead/%s.fw", acpi_id->id);
  
  		for (i = 0; i < strlen(data->fw_name); i++)
  			data->fw_name[i] = tolower(data->fw_name[i]);
  	} else {
  		snprintf(data->fw_name, sizeof(data->fw_name),
  			 "silead/%s.fw", id->name);
  	}
  
  	return 0;
  }
  #else
  static int silead_ts_set_default_fw_name(struct silead_ts_data *data,
  					 const struct i2c_device_id *id)
  {
  	snprintf(data->fw_name, sizeof(data->fw_name),
  		 "silead/%s.fw", id->name);
  	return 0;
  }
  #endif
  
  static void silead_disable_regulator(void *arg)
  {
  	struct silead_ts_data *data = arg;
  
  	regulator_bulk_disable(ARRAY_SIZE(data->regulators), data->regulators);
  }
  
  static int silead_ts_probe(struct i2c_client *client,
  			   const struct i2c_device_id *id)
  {
  	struct silead_ts_data *data;
  	struct device *dev = &client->dev;
  	int error;
  
  	if (!i2c_check_functionality(client->adapter,
  				     I2C_FUNC_I2C |
  				     I2C_FUNC_SMBUS_READ_I2C_BLOCK |
  				     I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)) {
  		dev_err(dev, "I2C functionality check failed\n");
  		return -ENXIO;
  	}
  
  	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
  	if (!data)
  		return -ENOMEM;
  
  	i2c_set_clientdata(client, data);
  	data->client = client;
  
  	error = silead_ts_set_default_fw_name(data, id);
  	if (error)
  		return error;
  
  	silead_ts_read_props(client);
  
  	/* We must have the IRQ provided by DT or ACPI subsytem */
  	if (client->irq <= 0)
  		return -ENODEV;
  
  	data->regulators[0].supply = "vddio";
  	data->regulators[1].supply = "avdd";
  	error = devm_regulator_bulk_get(dev, ARRAY_SIZE(data->regulators),
  					data->regulators);
  	if (error)
  		return error;
  
  	/*
  	 * Enable regulators at probe and disable them at remove, we need
  	 * to keep the chip powered otherwise it forgets its firmware.
  	 */
  	error = regulator_bulk_enable(ARRAY_SIZE(data->regulators),
  				      data->regulators);
  	if (error)
  		return error;
  
  	error = devm_add_action_or_reset(dev, silead_disable_regulator, data);
  	if (error)
  		return error;
  
  	/* Power GPIO pin */
  	data->gpio_power = devm_gpiod_get_optional(dev, "power", GPIOD_OUT_LOW);
  	if (IS_ERR(data->gpio_power)) {
  		if (PTR_ERR(data->gpio_power) != -EPROBE_DEFER)
  			dev_err(dev, "Shutdown GPIO request failed\n");
  		return PTR_ERR(data->gpio_power);
  	}
  
  	error = silead_ts_setup(client);
  	if (error)
  		return error;
  
  	error = silead_ts_request_input_dev(data);
  	if (error)
  		return error;
  
  	error = devm_request_threaded_irq(dev, client->irq,
  					  NULL, silead_ts_threaded_irq_handler,
  					  IRQF_ONESHOT, client->name, data);
  	if (error) {
  		if (error != -EPROBE_DEFER)
  			dev_err(dev, "IRQ request failed %d\n", error);
  		return error;
  	}
  
  	return 0;
  }
  
  static int __maybe_unused silead_ts_suspend(struct device *dev)
  {
  	struct i2c_client *client = to_i2c_client(dev);
  
  	disable_irq(client->irq);
  	silead_ts_set_power(client, SILEAD_POWER_OFF);
  	return 0;
  }
  
  static int __maybe_unused silead_ts_resume(struct device *dev)
  {
  	struct i2c_client *client = to_i2c_client(dev);
  	int error, status;
  
  	silead_ts_set_power(client, SILEAD_POWER_ON);
  
  	error = silead_ts_reset(client);
  	if (error)
  		return error;
  
  	error = silead_ts_startup(client);
  	if (error)
  		return error;
  
  	status = silead_ts_get_status(client);
  	if (status != SILEAD_STATUS_OK) {
  		dev_err(dev, "Resume error, status: 0x%02x\n", status);
  		return -ENODEV;
  	}
  
  	enable_irq(client->irq);
  
  	return 0;
  }
  
  static SIMPLE_DEV_PM_OPS(silead_ts_pm, silead_ts_suspend, silead_ts_resume);
  
  static const struct i2c_device_id silead_ts_id[] = {
  	{ "gsl1680", 0 },
  	{ "gsl1688", 0 },
  	{ "gsl3670", 0 },
  	{ "gsl3675", 0 },
  	{ "gsl3692", 0 },
  	{ "mssl1680", 0 },
  	{ }
  };
  MODULE_DEVICE_TABLE(i2c, silead_ts_id);
  
  #ifdef CONFIG_ACPI
  static const struct acpi_device_id silead_ts_acpi_match[] = {
  	{ "GSL1680", 0 },
  	{ "GSL1688", 0 },
  	{ "GSL3670", 0 },
  	{ "GSL3675", 0 },
  	{ "GSL3692", 0 },
  	{ "MSSL1680", 0 },
  	{ "MSSL0001", 0 },
  	{ "MSSL0002", 0 },
  	{ }
  };
  MODULE_DEVICE_TABLE(acpi, silead_ts_acpi_match);
  #endif
  
  #ifdef CONFIG_OF
  static const struct of_device_id silead_ts_of_match[] = {
  	{ .compatible = "silead,gsl1680" },
  	{ .compatible = "silead,gsl1688" },
  	{ .compatible = "silead,gsl3670" },
  	{ .compatible = "silead,gsl3675" },
  	{ .compatible = "silead,gsl3692" },
  	{ },
  };
  MODULE_DEVICE_TABLE(of, silead_ts_of_match);
  #endif
  
  static struct i2c_driver silead_ts_driver = {
  	.probe = silead_ts_probe,
  	.id_table = silead_ts_id,
  	.driver = {
  		.name = SILEAD_TS_NAME,
  		.acpi_match_table = ACPI_PTR(silead_ts_acpi_match),
  		.of_match_table = of_match_ptr(silead_ts_of_match),
  		.pm = &silead_ts_pm,
  	},
  };
  module_i2c_driver(silead_ts_driver);
  
  MODULE_AUTHOR("Robert Dolca <robert.dolca@intel.com>");
  MODULE_DESCRIPTION("Silead I2C touchscreen driver");
  MODULE_LICENSE("GPL");
  