/*
   * Copyright (C) ST-Ericsson SA 2010
   *
   * Author: Jayeeta Banerjee <jayeeta.banerjee@stericsson.com>
   * Author: Sundar Iyer <sundar.iyer@stericsson.com>
   *
   * License Terms: GNU General Public License, version 2
   *
   * TC35893 MFD Keypad Controller driver
   */
  
  #include <linux/module.h>
  #include <linux/interrupt.h>
  #include <linux/input.h>
  #include <linux/platform_device.h>
  #include <linux/input/matrix_keypad.h>
  #include <linux/i2c.h>
  #include <linux/slab.h>
  #include <linux/mfd/tc3589x.h>
  #include <linux/device.h>
  
  /* Maximum supported keypad matrix row/columns size */
  #define TC3589x_MAX_KPROW               8
  #define TC3589x_MAX_KPCOL               12
  
  /* keypad related Constants */
  #define TC3589x_MAX_DEBOUNCE_SETTLE     0xFF
  #define DEDICATED_KEY_VAL		0xFF
  
  /* Pull up/down masks */
  #define TC3589x_NO_PULL_MASK		0x0
  #define TC3589x_PULL_DOWN_MASK		0x1
  #define TC3589x_PULL_UP_MASK		0x2
  #define TC3589x_PULLUP_ALL_MASK		0xAA
  #define TC3589x_IO_PULL_VAL(index, mask)	((mask)<<((index)%4)*2))
  
  /* Bit masks for IOCFG register */
  #define IOCFG_BALLCFG		0x01
  #define IOCFG_IG		0x08
  
  #define KP_EVCODE_COL_MASK	0x0F
  #define KP_EVCODE_ROW_MASK	0x70
  #define KP_RELEASE_EVT_MASK	0x80
  
  #define KP_ROW_SHIFT		4
  
  #define KP_NO_VALID_KEY_MASK	0x7F
  
  /* bit masks for RESTCTRL register */
  #define TC3589x_KBDRST		0x2
  #define TC3589x_IRQRST		0x10
  #define TC3589x_RESET_ALL	0x1B
  
  /* KBDMFS register bit mask */
  #define TC3589x_KBDMFS_EN	0x1
  
  /* CLKEN register bitmask */
  #define KPD_CLK_EN		0x1
  
  /* RSTINTCLR register bit mask */
  #define IRQ_CLEAR		0x1
  
  /* bit masks for keyboard interrupts*/
  #define TC3589x_EVT_LOSS_INT	0x8
  #define TC3589x_EVT_INT		0x4
  #define TC3589x_KBD_LOSS_INT	0x2
  #define TC3589x_KBD_INT		0x1
  
  /* bit masks for keyboard interrupt clear*/
  #define TC3589x_EVT_INT_CLR	0x2
  #define TC3589x_KBD_INT_CLR	0x1
  
  /**
   * struct tc35893_keypad_platform_data - platform specific keypad data
   * @keymap_data:        matrix scan code table for keycodes
   * @krow:               mask for available rows, value is 0xFF
   * @kcol:               mask for available columns, value is 0xFF
   * @debounce_period:    platform specific debounce time
   * @settle_time:        platform specific settle down time
   * @irqtype:            type of interrupt, falling or rising edge
   * @enable_wakeup:      specifies if keypad event can wake up system from sleep
   * @no_autorepeat:      flag for auto repetition
   */
  struct tc3589x_keypad_platform_data {
  	const struct matrix_keymap_data *keymap_data;
  	u8                      krow;
  	u8                      kcol;
  	u8                      debounce_period;
  	u8                      settle_time;
  	unsigned long           irqtype;
  	bool                    enable_wakeup;
  	bool                    no_autorepeat;
  };
  
  /**
   * struct tc_keypad - data structure used by keypad driver
   * @tc3589x:    pointer to tc35893
   * @input:      pointer to input device object
   * @board:      keypad platform device
   * @krow:	number of rows
   * @kcol:	number of columns
   * @keymap:     matrix scan code table for keycodes
   * @keypad_stopped: holds keypad status
   */
  struct tc_keypad {
  	struct tc3589x *tc3589x;
  	struct input_dev *input;
  	const struct tc3589x_keypad_platform_data *board;
  	unsigned int krow;
  	unsigned int kcol;
  	unsigned short *keymap;
  	bool keypad_stopped;
  };
  
  static int tc3589x_keypad_init_key_hardware(struct tc_keypad *keypad)
  {
  	int ret;
  	struct tc3589x *tc3589x = keypad->tc3589x;
  	const struct tc3589x_keypad_platform_data *board = keypad->board;
  
  	/* validate platform configuration */
  	if (board->kcol > TC3589x_MAX_KPCOL || board->krow > TC3589x_MAX_KPROW)
  		return -EINVAL;
  
  	/* configure KBDSIZE 4 LSbits for cols and 4 MSbits for rows */
  	ret = tc3589x_reg_write(tc3589x, TC3589x_KBDSIZE,
  			(board->krow << KP_ROW_SHIFT) | board->kcol);
  	if (ret < 0)
  		return ret;
  
  	/* configure dedicated key config, no dedicated key selected */
  	ret = tc3589x_reg_write(tc3589x, TC3589x_KBCFG_LSB, DEDICATED_KEY_VAL);
  	if (ret < 0)
  		return ret;
  
  	ret = tc3589x_reg_write(tc3589x, TC3589x_KBCFG_MSB, DEDICATED_KEY_VAL);
  	if (ret < 0)
  		return ret;
  
  	/* Configure settle time */
  	ret = tc3589x_reg_write(tc3589x, TC3589x_KBDSETTLE_REG,
  				board->settle_time);
  	if (ret < 0)
  		return ret;
  
  	/* Configure debounce time */
  	ret = tc3589x_reg_write(tc3589x, TC3589x_KBDBOUNCE,
  				board->debounce_period);
  	if (ret < 0)
  		return ret;
  
  	/* Start of initialise keypad GPIOs */
  	ret = tc3589x_set_bits(tc3589x, TC3589x_IOCFG, 0x0, IOCFG_IG);
  	if (ret < 0)
  		return ret;
  
  	/* Configure pull-up resistors for all row GPIOs */
  	ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG0_LSB,
  					TC3589x_PULLUP_ALL_MASK);
  	if (ret < 0)
  		return ret;
  
  	ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG0_MSB,
  					TC3589x_PULLUP_ALL_MASK);
  	if (ret < 0)
  		return ret;
  
  	/* Configure pull-up resistors for all column GPIOs */
  	ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG1_LSB,
  			TC3589x_PULLUP_ALL_MASK);
  	if (ret < 0)
  		return ret;
  
  	ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG1_MSB,
  			TC3589x_PULLUP_ALL_MASK);
  	if (ret < 0)
  		return ret;
  
  	ret = tc3589x_reg_write(tc3589x, TC3589x_IOPULLCFG2_LSB,
  			TC3589x_PULLUP_ALL_MASK);
  
  	return ret;
  }
  
  #define TC35893_DATA_REGS		4
  #define TC35893_KEYCODE_FIFO_EMPTY	0x7f
  #define TC35893_KEYCODE_FIFO_CLEAR	0xff
  #define TC35893_KEYPAD_ROW_SHIFT	0x3
  
  static irqreturn_t tc3589x_keypad_irq(int irq, void *dev)
  {
  	struct tc_keypad *keypad = dev;
  	struct tc3589x *tc3589x = keypad->tc3589x;
  	u8 i, row_index, col_index, kbd_code, up;
  	u8 code;
  
  	for (i = 0; i < TC35893_DATA_REGS * 2; i++) {
  		kbd_code = tc3589x_reg_read(tc3589x, TC3589x_EVTCODE_FIFO);
  
  		/* loop till fifo is empty and no more keys are pressed */
  		if (kbd_code == TC35893_KEYCODE_FIFO_EMPTY ||
  				kbd_code == TC35893_KEYCODE_FIFO_CLEAR)
  			continue;
  
  		/* valid key is found */
  		col_index = kbd_code & KP_EVCODE_COL_MASK;
  		row_index = (kbd_code & KP_EVCODE_ROW_MASK) >> KP_ROW_SHIFT;
  		code = MATRIX_SCAN_CODE(row_index, col_index,
  						TC35893_KEYPAD_ROW_SHIFT);
  		up = kbd_code & KP_RELEASE_EVT_MASK;
  
  		input_event(keypad->input, EV_MSC, MSC_SCAN, code);
  		input_report_key(keypad->input, keypad->keymap[code], !up);
  		input_sync(keypad->input);
  	}
  
  	/* clear IRQ */
  	tc3589x_set_bits(tc3589x, TC3589x_KBDIC,
  			0x0, TC3589x_EVT_INT_CLR | TC3589x_KBD_INT_CLR);
  	/* enable IRQ */
  	tc3589x_set_bits(tc3589x, TC3589x_KBDMSK,
  			0x0, TC3589x_EVT_LOSS_INT | TC3589x_EVT_INT);
  
  	return IRQ_HANDLED;
  }
  
  static int tc3589x_keypad_enable(struct tc_keypad *keypad)
  {
  	struct tc3589x *tc3589x = keypad->tc3589x;
  	int ret;
  
  	/* pull the keypad module out of reset */
  	ret = tc3589x_set_bits(tc3589x, TC3589x_RSTCTRL, TC3589x_KBDRST, 0x0);
  	if (ret < 0)
  		return ret;
  
  	/* configure KBDMFS */
  	ret = tc3589x_set_bits(tc3589x, TC3589x_KBDMFS, 0x0, TC3589x_KBDMFS_EN);
  	if (ret < 0)
  		return ret;
  
  	/* enable the keypad clock */
  	ret = tc3589x_set_bits(tc3589x, TC3589x_CLKEN, 0x0, KPD_CLK_EN);
  	if (ret < 0)
  		return ret;
  
  	/* clear pending IRQs */
  	ret =  tc3589x_set_bits(tc3589x, TC3589x_RSTINTCLR, 0x0, 0x1);
  	if (ret < 0)
  		return ret;
  
  	/* enable the IRQs */
  	ret = tc3589x_set_bits(tc3589x, TC3589x_KBDMSK, 0x0,
  					TC3589x_EVT_LOSS_INT | TC3589x_EVT_INT);
  	if (ret < 0)
  		return ret;
  
  	keypad->keypad_stopped = false;
  
  	return ret;
  }
  
  static int tc3589x_keypad_disable(struct tc_keypad *keypad)
  {
  	struct tc3589x *tc3589x = keypad->tc3589x;
  	int ret;
  
  	/* clear IRQ */
  	ret = tc3589x_set_bits(tc3589x, TC3589x_KBDIC,
  			0x0, TC3589x_EVT_INT_CLR | TC3589x_KBD_INT_CLR);
  	if (ret < 0)
  		return ret;
  
  	/* disable all interrupts */
  	ret = tc3589x_set_bits(tc3589x, TC3589x_KBDMSK,
  			~(TC3589x_EVT_LOSS_INT | TC3589x_EVT_INT), 0x0);
  	if (ret < 0)
  		return ret;
  
  	/* disable the keypad module */
  	ret = tc3589x_set_bits(tc3589x, TC3589x_CLKEN, 0x1, 0x0);
  	if (ret < 0)
  		return ret;
  
  	/* put the keypad module into reset */
  	ret = tc3589x_set_bits(tc3589x, TC3589x_RSTCTRL, TC3589x_KBDRST, 0x1);
  
  	keypad->keypad_stopped = true;
  
  	return ret;
  }
  
  static int tc3589x_keypad_open(struct input_dev *input)
  {
  	int error;
  	struct tc_keypad *keypad = input_get_drvdata(input);
  
  	/* enable the keypad module */
  	error = tc3589x_keypad_enable(keypad);
  	if (error < 0) {
  		dev_err(&input->dev, "failed to enable keypad module
  ");
  		return error;
  	}
  
  	error = tc3589x_keypad_init_key_hardware(keypad);
  	if (error < 0) {
  		dev_err(&input->dev, "failed to configure keypad module
  ");
  		return error;
  	}
  
  	return 0;
  }
  
  static void tc3589x_keypad_close(struct input_dev *input)
  {
  	struct tc_keypad *keypad = input_get_drvdata(input);
  
  	/* disable the keypad module */
  	tc3589x_keypad_disable(keypad);
  }
  
  static const struct tc3589x_keypad_platform_data *
  tc3589x_keypad_of_probe(struct device *dev)
  {
  	struct device_node *np = dev->of_node;
  	struct tc3589x_keypad_platform_data *plat;
  	u32 cols, rows;
  	u32 debounce_ms;
  	int proplen;
  
  	if (!np)
  		return ERR_PTR(-ENODEV);
  
  	plat = devm_kzalloc(dev, sizeof(*plat), GFP_KERNEL);
  	if (!plat)
  		return ERR_PTR(-ENOMEM);
  
  	of_property_read_u32(np, "keypad,num-columns", &cols);
  	of_property_read_u32(np, "keypad,num-rows", &rows);
  	plat->kcol = (u8) cols;
  	plat->krow = (u8) rows;
  	if (!plat->krow || !plat->kcol ||
  	     plat->krow > TC_KPD_ROWS || plat->kcol > TC_KPD_COLUMNS) {
  		dev_err(dev,
  			"keypad columns/rows not properly specified (%ux%u)
  ",
  			plat->kcol, plat->krow);
  		return ERR_PTR(-EINVAL);
  	}
  
  	if (!of_get_property(np, "linux,keymap", &proplen)) {
  		dev_err(dev, "property linux,keymap not found
  ");
  		return ERR_PTR(-ENOENT);
  	}
  
  	plat->no_autorepeat = of_property_read_bool(np, "linux,no-autorepeat");
  
  	plat->enable_wakeup = of_property_read_bool(np, "wakeup-source") ||
  			      /* legacy name */
  			      of_property_read_bool(np, "linux,wakeup");
  
  	/* The custom delay format is ms/16 */
  	of_property_read_u32(np, "debounce-delay-ms", &debounce_ms);
  	if (debounce_ms)
  		plat->debounce_period = debounce_ms * 16;
  	else
  		plat->debounce_period = TC_KPD_DEBOUNCE_PERIOD;
  
  	plat->settle_time = TC_KPD_SETTLE_TIME;
  	/* FIXME: should be property of the IRQ resource? */
  	plat->irqtype = IRQF_TRIGGER_FALLING;
  
  	return plat;
  }
  
  static int tc3589x_keypad_probe(struct platform_device *pdev)
  {
  	struct tc3589x *tc3589x = dev_get_drvdata(pdev->dev.parent);
  	struct tc_keypad *keypad;
  	struct input_dev *input;
  	const struct tc3589x_keypad_platform_data *plat;
  	int error, irq;
  
  	plat = tc3589x_keypad_of_probe(&pdev->dev);
  	if (IS_ERR(plat)) {
  		dev_err(&pdev->dev, "invalid keypad platform data
  ");
  		return PTR_ERR(plat);
  	}
  
  	irq = platform_get_irq(pdev, 0);
  	if (irq < 0)
  		return irq;
  
  	keypad = devm_kzalloc(&pdev->dev, sizeof(struct tc_keypad),
  			      GFP_KERNEL);
  	if (!keypad)
  		return -ENOMEM;
  
  	input = devm_input_allocate_device(&pdev->dev);
  	if (!input) {
  		dev_err(&pdev->dev, "failed to allocate input device
  ");
  		return -ENOMEM;
  	}
  
  	keypad->board = plat;
  	keypad->input = input;
  	keypad->tc3589x = tc3589x;
  
  	input->id.bustype = BUS_I2C;
  	input->name = pdev->name;
  	input->dev.parent = &pdev->dev;
  
  	input->open = tc3589x_keypad_open;
  	input->close = tc3589x_keypad_close;
  
  	error = matrix_keypad_build_keymap(plat->keymap_data, NULL,
  					   TC3589x_MAX_KPROW, TC3589x_MAX_KPCOL,
  					   NULL, input);
  	if (error) {
  		dev_err(&pdev->dev, "Failed to build keymap
  ");
  		return error;
  	}
  
  	keypad->keymap = input->keycode;
  
  	input_set_capability(input, EV_MSC, MSC_SCAN);
  	if (!plat->no_autorepeat)
  		__set_bit(EV_REP, input->evbit);
  
  	input_set_drvdata(input, keypad);
  
  	tc3589x_keypad_disable(keypad);
  
  	error = devm_request_threaded_irq(&pdev->dev, irq,
  					  NULL, tc3589x_keypad_irq,
  					  plat->irqtype | IRQF_ONESHOT,
  					  "tc3589x-keypad", keypad);
  	if (error) {
  		dev_err(&pdev->dev,
  				"Could not allocate irq %d,error %d
  ",
  				irq, error);
  		return error;
  	}
  
  	error = input_register_device(input);
  	if (error) {
  		dev_err(&pdev->dev, "Could not register input device
  ");
  		return error;
  	}
  
  	/* let platform decide if keypad is a wakeup source or not */
  	device_init_wakeup(&pdev->dev, plat->enable_wakeup);
  	device_set_wakeup_capable(&pdev->dev, plat->enable_wakeup);
  
  	platform_set_drvdata(pdev, keypad);
  
  	return 0;
  }
  
  #ifdef CONFIG_PM_SLEEP
  static int tc3589x_keypad_suspend(struct device *dev)
  {
  	struct platform_device *pdev = to_platform_device(dev);
  	struct tc_keypad *keypad = platform_get_drvdata(pdev);
  	int irq = platform_get_irq(pdev, 0);
  
  	/* keypad is already off; we do nothing */
  	if (keypad->keypad_stopped)
  		return 0;
  
  	/* if device is not a wakeup source, disable it for powersave */
  	if (!device_may_wakeup(&pdev->dev))
  		tc3589x_keypad_disable(keypad);
  	else
  		enable_irq_wake(irq);
  
  	return 0;
  }
  
  static int tc3589x_keypad_resume(struct device *dev)
  {
  	struct platform_device *pdev = to_platform_device(dev);
  	struct tc_keypad *keypad = platform_get_drvdata(pdev);
  	int irq = platform_get_irq(pdev, 0);
  
  	if (!keypad->keypad_stopped)
  		return 0;
  
  	/* enable the device to resume normal operations */
  	if (!device_may_wakeup(&pdev->dev))
  		tc3589x_keypad_enable(keypad);
  	else
  		disable_irq_wake(irq);
  
  	return 0;
  }
  #endif
  
  static SIMPLE_DEV_PM_OPS(tc3589x_keypad_dev_pm_ops,
  			 tc3589x_keypad_suspend, tc3589x_keypad_resume);
  
  static struct platform_driver tc3589x_keypad_driver = {
  	.driver	= {
  		.name	= "tc3589x-keypad",
  		.pm	= &tc3589x_keypad_dev_pm_ops,
  	},
  	.probe	= tc3589x_keypad_probe,
  };
  module_platform_driver(tc3589x_keypad_driver);
  
  MODULE_LICENSE("GPL v2");
  MODULE_AUTHOR("Jayeeta Banerjee/Sundar Iyer");
  MODULE_DESCRIPTION("TC35893 Keypad Driver");
  MODULE_ALIAS("platform:tc3589x-keypad");