/* Copyright (c) 2009-2011, Code Aurora Forum. All rights reserved.
   *
   * 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 <linux/module.h>
  #include <linux/platform_device.h>
  #include <linux/kernel.h>
  #include <linux/interrupt.h>
  #include <linux/slab.h>
  #include <linux/input.h>
  #include <linux/bitops.h>
  #include <linux/delay.h>
  #include <linux/mutex.h>
  #include <linux/regmap.h>
  #include <linux/of.h>
  #include <linux/input/matrix_keypad.h>
  
  #define PM8XXX_MAX_ROWS		18
  #define PM8XXX_MAX_COLS		8
  #define PM8XXX_ROW_SHIFT	3
  #define PM8XXX_MATRIX_MAX_SIZE	(PM8XXX_MAX_ROWS * PM8XXX_MAX_COLS)
  
  #define PM8XXX_MIN_ROWS		5
  #define PM8XXX_MIN_COLS		5
  
  #define MAX_SCAN_DELAY		128
  #define MIN_SCAN_DELAY		1
  
  /* in nanoseconds */
  #define MAX_ROW_HOLD_DELAY	122000
  #define MIN_ROW_HOLD_DELAY	30500
  
  #define MAX_DEBOUNCE_TIME	20
  #define MIN_DEBOUNCE_TIME	5
  
  #define KEYP_CTRL			0x148
  
  #define KEYP_CTRL_EVNTS			BIT(0)
  #define KEYP_CTRL_EVNTS_MASK		0x3
  
  #define KEYP_CTRL_SCAN_COLS_SHIFT	5
  #define KEYP_CTRL_SCAN_COLS_MIN		5
  #define KEYP_CTRL_SCAN_COLS_BITS	0x3
  
  #define KEYP_CTRL_SCAN_ROWS_SHIFT	2
  #define KEYP_CTRL_SCAN_ROWS_MIN		5
  #define KEYP_CTRL_SCAN_ROWS_BITS	0x7
  
  #define KEYP_CTRL_KEYP_EN		BIT(7)
  
  #define KEYP_SCAN			0x149
  
  #define KEYP_SCAN_READ_STATE		BIT(0)
  #define KEYP_SCAN_DBOUNCE_SHIFT		1
  #define KEYP_SCAN_PAUSE_SHIFT		3
  #define KEYP_SCAN_ROW_HOLD_SHIFT	6
  
  #define KEYP_TEST			0x14A
  
  #define KEYP_TEST_CLEAR_RECENT_SCAN	BIT(6)
  #define KEYP_TEST_CLEAR_OLD_SCAN	BIT(5)
  #define KEYP_TEST_READ_RESET		BIT(4)
  #define KEYP_TEST_DTEST_EN		BIT(3)
  #define KEYP_TEST_ABORT_READ		BIT(0)
  
  #define KEYP_TEST_DBG_SELECT_SHIFT	1
  
  /* bits of these registers represent
   * '0' for key press
   * '1' for key release
   */
  #define KEYP_RECENT_DATA		0x14B
  #define KEYP_OLD_DATA			0x14C
  
  #define KEYP_CLOCK_FREQ			32768
  
  /**
   * struct pmic8xxx_kp - internal keypad data structure
   * @num_cols - number of columns of keypad
   * @num_rows - number of row of keypad
   * @input - input device pointer for keypad
   * @regmap - regmap handle
   * @key_sense_irq - key press/release irq number
   * @key_stuck_irq - key stuck notification irq number
   * @keycodes - array to hold the key codes
   * @dev - parent device pointer
   * @keystate - present key press/release state
   * @stuckstate - present state when key stuck irq
   * @ctrl_reg - control register value
   */
  struct pmic8xxx_kp {
  	unsigned int num_rows;
  	unsigned int num_cols;
  	struct input_dev *input;
  	struct regmap *regmap;
  	int key_sense_irq;
  	int key_stuck_irq;
  
  	unsigned short keycodes[PM8XXX_MATRIX_MAX_SIZE];
  
  	struct device *dev;
  	u16 keystate[PM8XXX_MAX_ROWS];
  	u16 stuckstate[PM8XXX_MAX_ROWS];
  
  	u8 ctrl_reg;
  };
  
  static u8 pmic8xxx_col_state(struct pmic8xxx_kp *kp, u8 col)
  {
  	/* all keys pressed on that particular row? */
  	if (col == 0x00)
  		return 1 << kp->num_cols;
  	else
  		return col & ((1 << kp->num_cols) - 1);
  }
  
  /*
   * Synchronous read protocol for RevB0 onwards:
   *
   * 1. Write '1' to ReadState bit in KEYP_SCAN register
   * 2. Wait 2*32KHz clocks, so that HW can successfully enter read mode
   *    synchronously
   * 3. Read rows in old array first if events are more than one
   * 4. Read rows in recent array
   * 5. Wait 4*32KHz clocks
   * 6. Write '0' to ReadState bit of KEYP_SCAN register so that hw can
   *    synchronously exit read mode.
   */
  static int pmic8xxx_chk_sync_read(struct pmic8xxx_kp *kp)
  {
  	int rc;
  	unsigned int scan_val;
  
  	rc = regmap_read(kp->regmap, KEYP_SCAN, &scan_val);
  	if (rc < 0) {
  		dev_err(kp->dev, "Error reading KEYP_SCAN reg, rc=%d
  ", rc);
  		return rc;
  	}
  
  	scan_val |= 0x1;
  
  	rc = regmap_write(kp->regmap, KEYP_SCAN, scan_val);
  	if (rc < 0) {
  		dev_err(kp->dev, "Error writing KEYP_SCAN reg, rc=%d
  ", rc);
  		return rc;
  	}
  
  	/* 2 * 32KHz clocks */
  	udelay((2 * DIV_ROUND_UP(USEC_PER_SEC, KEYP_CLOCK_FREQ)) + 1);
  
  	return rc;
  }
  
  static int pmic8xxx_kp_read_data(struct pmic8xxx_kp *kp, u16 *state,
  					u16 data_reg, int read_rows)
  {
  	int rc, row;
  	unsigned int val;
  
  	for (row = 0; row < read_rows; row++) {
  		rc = regmap_read(kp->regmap, data_reg, &val);
  		if (rc)
  			return rc;
  		dev_dbg(kp->dev, "%d = %d
  ", row, val);
  		state[row] = pmic8xxx_col_state(kp, val);
  	}
  
  	return 0;
  }
  
  static int pmic8xxx_kp_read_matrix(struct pmic8xxx_kp *kp, u16 *new_state,
  					 u16 *old_state)
  {
  	int rc, read_rows;
  	unsigned int scan_val;
  
  	if (kp->num_rows < PM8XXX_MIN_ROWS)
  		read_rows = PM8XXX_MIN_ROWS;
  	else
  		read_rows = kp->num_rows;
  
  	pmic8xxx_chk_sync_read(kp);
  
  	if (old_state) {
  		rc = pmic8xxx_kp_read_data(kp, old_state, KEYP_OLD_DATA,
  						read_rows);
  		if (rc < 0) {
  			dev_err(kp->dev,
  				"Error reading KEYP_OLD_DATA, rc=%d
  ", rc);
  			return rc;
  		}
  	}
  
  	rc = pmic8xxx_kp_read_data(kp, new_state, KEYP_RECENT_DATA,
  					 read_rows);
  	if (rc < 0) {
  		dev_err(kp->dev,
  			"Error reading KEYP_RECENT_DATA, rc=%d
  ", rc);
  		return rc;
  	}
  
  	/* 4 * 32KHz clocks */
  	udelay((4 * DIV_ROUND_UP(USEC_PER_SEC, KEYP_CLOCK_FREQ)) + 1);
  
  	rc = regmap_read(kp->regmap, KEYP_SCAN, &scan_val);
  	if (rc < 0) {
  		dev_err(kp->dev, "Error reading KEYP_SCAN reg, rc=%d
  ", rc);
  		return rc;
  	}
  
  	scan_val &= 0xFE;
  	rc = regmap_write(kp->regmap, KEYP_SCAN, scan_val);
  	if (rc < 0)
  		dev_err(kp->dev, "Error writing KEYP_SCAN reg, rc=%d
  ", rc);
  
  	return rc;
  }
  
  static void __pmic8xxx_kp_scan_matrix(struct pmic8xxx_kp *kp, u16 *new_state,
  					 u16 *old_state)
  {
  	int row, col, code;
  
  	for (row = 0; row < kp->num_rows; row++) {
  		int bits_changed = new_state[row] ^ old_state[row];
  
  		if (!bits_changed)
  			continue;
  
  		for (col = 0; col < kp->num_cols; col++) {
  			if (!(bits_changed & (1 << col)))
  				continue;
  
  			dev_dbg(kp->dev, "key [%d:%d] %s
  ", row, col,
  					!(new_state[row] & (1 << col)) ?
  					"pressed" : "released");
  
  			code = MATRIX_SCAN_CODE(row, col, PM8XXX_ROW_SHIFT);
  
  			input_event(kp->input, EV_MSC, MSC_SCAN, code);
  			input_report_key(kp->input,
  					kp->keycodes[code],
  					!(new_state[row] & (1 << col)));
  
  			input_sync(kp->input);
  		}
  	}
  }
  
  static bool pmic8xxx_detect_ghost_keys(struct pmic8xxx_kp *kp, u16 *new_state)
  {
  	int row, found_first = -1;
  	u16 check, row_state;
  
  	check = 0;
  	for (row = 0; row < kp->num_rows; row++) {
  		row_state = (~new_state[row]) &
  				 ((1 << kp->num_cols) - 1);
  
  		if (hweight16(row_state) > 1) {
  			if (found_first == -1)
  				found_first = row;
  			if (check & row_state) {
  				dev_dbg(kp->dev, "detected ghost key on row[%d]"
  					 " and row[%d]
  ", found_first, row);
  				return true;
  			}
  		}
  		check |= row_state;
  	}
  	return false;
  }
  
  static int pmic8xxx_kp_scan_matrix(struct pmic8xxx_kp *kp, unsigned int events)
  {
  	u16 new_state[PM8XXX_MAX_ROWS];
  	u16 old_state[PM8XXX_MAX_ROWS];
  	int rc;
  
  	switch (events) {
  	case 0x1:
  		rc = pmic8xxx_kp_read_matrix(kp, new_state, NULL);
  		if (rc < 0)
  			return rc;
  
  		/* detecting ghost key is not an error */
  		if (pmic8xxx_detect_ghost_keys(kp, new_state))
  			return 0;
  		__pmic8xxx_kp_scan_matrix(kp, new_state, kp->keystate);
  		memcpy(kp->keystate, new_state, sizeof(new_state));
  	break;
  	case 0x3: /* two events - eventcounter is gray-coded */
  		rc = pmic8xxx_kp_read_matrix(kp, new_state, old_state);
  		if (rc < 0)
  			return rc;
  
  		__pmic8xxx_kp_scan_matrix(kp, old_state, kp->keystate);
  		__pmic8xxx_kp_scan_matrix(kp, new_state, old_state);
  		memcpy(kp->keystate, new_state, sizeof(new_state));
  	break;
  	case 0x2:
  		dev_dbg(kp->dev, "Some key events were lost
  ");
  		rc = pmic8xxx_kp_read_matrix(kp, new_state, old_state);
  		if (rc < 0)
  			return rc;
  		__pmic8xxx_kp_scan_matrix(kp, old_state, kp->keystate);
  		__pmic8xxx_kp_scan_matrix(kp, new_state, old_state);
  		memcpy(kp->keystate, new_state, sizeof(new_state));
  	break;
  	default:
  		rc = -EINVAL;
  	}
  	return rc;
  }
  
  /*
   * NOTE: We are reading recent and old data registers blindly
   * whenever key-stuck interrupt happens, because events counter doesn't
   * get updated when this interrupt happens due to key stuck doesn't get
   * considered as key state change.
   *
   * We are not using old data register contents after they are being read
   * because it might report the key which was pressed before the key being stuck
   * as stuck key because it's pressed status is stored in the old data
   * register.
   */
  static irqreturn_t pmic8xxx_kp_stuck_irq(int irq, void *data)
  {
  	u16 new_state[PM8XXX_MAX_ROWS];
  	u16 old_state[PM8XXX_MAX_ROWS];
  	int rc;
  	struct pmic8xxx_kp *kp = data;
  
  	rc = pmic8xxx_kp_read_matrix(kp, new_state, old_state);
  	if (rc < 0) {
  		dev_err(kp->dev, "failed to read keypad matrix
  ");
  		return IRQ_HANDLED;
  	}
  
  	__pmic8xxx_kp_scan_matrix(kp, new_state, kp->stuckstate);
  
  	return IRQ_HANDLED;
  }
  
  static irqreturn_t pmic8xxx_kp_irq(int irq, void *data)
  {
  	struct pmic8xxx_kp *kp = data;
  	unsigned int ctrl_val, events;
  	int rc;
  
  	rc = regmap_read(kp->regmap, KEYP_CTRL, &ctrl_val);
  	if (rc < 0) {
  		dev_err(kp->dev, "failed to read keyp_ctrl register
  ");
  		return IRQ_HANDLED;
  	}
  
  	events = ctrl_val & KEYP_CTRL_EVNTS_MASK;
  
  	rc = pmic8xxx_kp_scan_matrix(kp, events);
  	if (rc < 0)
  		dev_err(kp->dev, "failed to scan matrix
  ");
  
  	return IRQ_HANDLED;
  }
  
  static int pmic8xxx_kpd_init(struct pmic8xxx_kp *kp,
  			     struct platform_device *pdev)
  {
  	const struct device_node *of_node = pdev->dev.of_node;
  	unsigned int scan_delay_ms;
  	unsigned int row_hold_ns;
  	unsigned int debounce_ms;
  	int bits, rc, cycles;
  	u8 scan_val = 0, ctrl_val = 0;
  	static const u8 row_bits[] = {
  		0, 1, 2, 3, 4, 4, 5, 5, 6, 6, 6, 7, 7, 7,
  	};
  
  	/* Find column bits */
  	if (kp->num_cols < KEYP_CTRL_SCAN_COLS_MIN)
  		bits = 0;
  	else
  		bits = kp->num_cols - KEYP_CTRL_SCAN_COLS_MIN;
  	ctrl_val = (bits & KEYP_CTRL_SCAN_COLS_BITS) <<
  		KEYP_CTRL_SCAN_COLS_SHIFT;
  
  	/* Find row bits */
  	if (kp->num_rows < KEYP_CTRL_SCAN_ROWS_MIN)
  		bits = 0;
  	else
  		bits = row_bits[kp->num_rows - KEYP_CTRL_SCAN_ROWS_MIN];
  
  	ctrl_val |= (bits << KEYP_CTRL_SCAN_ROWS_SHIFT);
  
  	rc = regmap_write(kp->regmap, KEYP_CTRL, ctrl_val);
  	if (rc < 0) {
  		dev_err(kp->dev, "Error writing KEYP_CTRL reg, rc=%d
  ", rc);
  		return rc;
  	}
  
  	if (of_property_read_u32(of_node, "scan-delay", &scan_delay_ms))
  		scan_delay_ms = MIN_SCAN_DELAY;
  
  	if (scan_delay_ms > MAX_SCAN_DELAY || scan_delay_ms < MIN_SCAN_DELAY ||
  	    !is_power_of_2(scan_delay_ms)) {
  		dev_err(&pdev->dev, "invalid keypad scan time supplied
  ");
  		return -EINVAL;
  	}
  
  	if (of_property_read_u32(of_node, "row-hold", &row_hold_ns))
  		row_hold_ns = MIN_ROW_HOLD_DELAY;
  
  	if (row_hold_ns > MAX_ROW_HOLD_DELAY ||
  	    row_hold_ns < MIN_ROW_HOLD_DELAY ||
  	    ((row_hold_ns % MIN_ROW_HOLD_DELAY) != 0)) {
  		dev_err(&pdev->dev, "invalid keypad row hold time supplied
  ");
  		return -EINVAL;
  	}
  
  	if (of_property_read_u32(of_node, "debounce", &debounce_ms))
  		debounce_ms = MIN_DEBOUNCE_TIME;
  
  	if (((debounce_ms % 5) != 0) ||
  	    debounce_ms > MAX_DEBOUNCE_TIME ||
  	    debounce_ms < MIN_DEBOUNCE_TIME) {
  		dev_err(&pdev->dev, "invalid debounce time supplied
  ");
  		return -EINVAL;
  	}
  
  	bits = (debounce_ms / 5) - 1;
  
  	scan_val |= (bits << KEYP_SCAN_DBOUNCE_SHIFT);
  
  	bits = fls(scan_delay_ms) - 1;
  	scan_val |= (bits << KEYP_SCAN_PAUSE_SHIFT);
  
  	/* Row hold time is a multiple of 32KHz cycles. */
  	cycles = (row_hold_ns * KEYP_CLOCK_FREQ) / NSEC_PER_SEC;
  
  	scan_val |= (cycles << KEYP_SCAN_ROW_HOLD_SHIFT);
  
  	rc = regmap_write(kp->regmap, KEYP_SCAN, scan_val);
  	if (rc)
  		dev_err(kp->dev, "Error writing KEYP_SCAN reg, rc=%d
  ", rc);
  
  	return rc;
  
  }
  
  static int pmic8xxx_kp_enable(struct pmic8xxx_kp *kp)
  {
  	int rc;
  
  	kp->ctrl_reg |= KEYP_CTRL_KEYP_EN;
  
  	rc = regmap_write(kp->regmap, KEYP_CTRL, kp->ctrl_reg);
  	if (rc < 0)
  		dev_err(kp->dev, "Error writing KEYP_CTRL reg, rc=%d
  ", rc);
  
  	return rc;
  }
  
  static int pmic8xxx_kp_disable(struct pmic8xxx_kp *kp)
  {
  	int rc;
  
  	kp->ctrl_reg &= ~KEYP_CTRL_KEYP_EN;
  
  	rc = regmap_write(kp->regmap, KEYP_CTRL, kp->ctrl_reg);
  	if (rc < 0)
  		return rc;
  
  	return rc;
  }
  
  static int pmic8xxx_kp_open(struct input_dev *dev)
  {
  	struct pmic8xxx_kp *kp = input_get_drvdata(dev);
  
  	return pmic8xxx_kp_enable(kp);
  }
  
  static void pmic8xxx_kp_close(struct input_dev *dev)
  {
  	struct pmic8xxx_kp *kp = input_get_drvdata(dev);
  
  	pmic8xxx_kp_disable(kp);
  }
  
  /*
   * keypad controller should be initialized in the following sequence
   * only, otherwise it might get into FSM stuck state.
   *
   * - Initialize keypad control parameters, like no. of rows, columns,
   *   timing values etc.,
   * - configure rows and column gpios pull up/down.
   * - set irq edge type.
   * - enable the keypad controller.
   */
  static int pmic8xxx_kp_probe(struct platform_device *pdev)
  {
  	struct device_node *np = pdev->dev.of_node;
  	unsigned int rows, cols;
  	bool repeat;
  	bool wakeup;
  	struct pmic8xxx_kp *kp;
  	int rc;
  	unsigned int ctrl_val;
  
  	rc = matrix_keypad_parse_of_params(&pdev->dev, &rows, &cols);
  	if (rc)
  		return rc;
  
  	if (cols > PM8XXX_MAX_COLS || rows > PM8XXX_MAX_ROWS ||
  	    cols < PM8XXX_MIN_COLS) {
  		dev_err(&pdev->dev, "invalid platform data
  ");
  		return -EINVAL;
  	}
  
  	repeat = !of_property_read_bool(np, "linux,input-no-autorepeat");
  
  	wakeup = of_property_read_bool(np, "wakeup-source") ||
  		 /* legacy name */
  		 of_property_read_bool(np, "linux,keypad-wakeup");
  
  	kp = devm_kzalloc(&pdev->dev, sizeof(*kp), GFP_KERNEL);
  	if (!kp)
  		return -ENOMEM;
  
  	kp->regmap = dev_get_regmap(pdev->dev.parent, NULL);
  	if (!kp->regmap)
  		return -ENODEV;
  
  	platform_set_drvdata(pdev, kp);
  
  	kp->num_rows	= rows;
  	kp->num_cols	= cols;
  	kp->dev		= &pdev->dev;
  
  	kp->input = devm_input_allocate_device(&pdev->dev);
  	if (!kp->input) {
  		dev_err(&pdev->dev, "unable to allocate input device
  ");
  		return -ENOMEM;
  	}
  
  	kp->key_sense_irq = platform_get_irq(pdev, 0);
  	if (kp->key_sense_irq < 0) {
  		dev_err(&pdev->dev, "unable to get keypad sense irq
  ");
  		return kp->key_sense_irq;
  	}
  
  	kp->key_stuck_irq = platform_get_irq(pdev, 1);
  	if (kp->key_stuck_irq < 0) {
  		dev_err(&pdev->dev, "unable to get keypad stuck irq
  ");
  		return kp->key_stuck_irq;
  	}
  
  	kp->input->name = "PMIC8XXX keypad";
  	kp->input->phys = "pmic8xxx_keypad/input0";
  
  	kp->input->id.bustype	= BUS_I2C;
  	kp->input->id.version	= 0x0001;
  	kp->input->id.product	= 0x0001;
  	kp->input->id.vendor	= 0x0001;
  
  	kp->input->open		= pmic8xxx_kp_open;
  	kp->input->close	= pmic8xxx_kp_close;
  
  	rc = matrix_keypad_build_keymap(NULL, NULL,
  					PM8XXX_MAX_ROWS, PM8XXX_MAX_COLS,
  					kp->keycodes, kp->input);
  	if (rc) {
  		dev_err(&pdev->dev, "failed to build keymap
  ");
  		return rc;
  	}
  
  	if (repeat)
  		__set_bit(EV_REP, kp->input->evbit);
  	input_set_capability(kp->input, EV_MSC, MSC_SCAN);
  
  	input_set_drvdata(kp->input, kp);
  
  	/* initialize keypad state */
  	memset(kp->keystate, 0xff, sizeof(kp->keystate));
  	memset(kp->stuckstate, 0xff, sizeof(kp->stuckstate));
  
  	rc = pmic8xxx_kpd_init(kp, pdev);
  	if (rc < 0) {
  		dev_err(&pdev->dev, "unable to initialize keypad controller
  ");
  		return rc;
  	}
  
  	rc = devm_request_any_context_irq(&pdev->dev, kp->key_sense_irq,
  			pmic8xxx_kp_irq, IRQF_TRIGGER_RISING, "pmic-keypad",
  			kp);
  	if (rc < 0) {
  		dev_err(&pdev->dev, "failed to request keypad sense irq
  ");
  		return rc;
  	}
  
  	rc = devm_request_any_context_irq(&pdev->dev, kp->key_stuck_irq,
  			pmic8xxx_kp_stuck_irq, IRQF_TRIGGER_RISING,
  			"pmic-keypad-stuck", kp);
  	if (rc < 0) {
  		dev_err(&pdev->dev, "failed to request keypad stuck irq
  ");
  		return rc;
  	}
  
  	rc = regmap_read(kp->regmap, KEYP_CTRL, &ctrl_val);
  	if (rc < 0) {
  		dev_err(&pdev->dev, "failed to read KEYP_CTRL register
  ");
  		return rc;
  	}
  
  	kp->ctrl_reg = ctrl_val;
  
  	rc = input_register_device(kp->input);
  	if (rc < 0) {
  		dev_err(&pdev->dev, "unable to register keypad input device
  ");
  		return rc;
  	}
  
  	device_init_wakeup(&pdev->dev, wakeup);
  
  	return 0;
  }
  
  #ifdef CONFIG_PM_SLEEP
  static int pmic8xxx_kp_suspend(struct device *dev)
  {
  	struct platform_device *pdev = to_platform_device(dev);
  	struct pmic8xxx_kp *kp = platform_get_drvdata(pdev);
  	struct input_dev *input_dev = kp->input;
  
  	if (device_may_wakeup(dev)) {
  		enable_irq_wake(kp->key_sense_irq);
  	} else {
  		mutex_lock(&input_dev->mutex);
  
  		if (input_dev->users)
  			pmic8xxx_kp_disable(kp);
  
  		mutex_unlock(&input_dev->mutex);
  	}
  
  	return 0;
  }
  
  static int pmic8xxx_kp_resume(struct device *dev)
  {
  	struct platform_device *pdev = to_platform_device(dev);
  	struct pmic8xxx_kp *kp = platform_get_drvdata(pdev);
  	struct input_dev *input_dev = kp->input;
  
  	if (device_may_wakeup(dev)) {
  		disable_irq_wake(kp->key_sense_irq);
  	} else {
  		mutex_lock(&input_dev->mutex);
  
  		if (input_dev->users)
  			pmic8xxx_kp_enable(kp);
  
  		mutex_unlock(&input_dev->mutex);
  	}
  
  	return 0;
  }
  #endif
  
  static SIMPLE_DEV_PM_OPS(pm8xxx_kp_pm_ops,
  			 pmic8xxx_kp_suspend, pmic8xxx_kp_resume);
  
  static const struct of_device_id pm8xxx_match_table[] = {
  	{ .compatible = "qcom,pm8058-keypad" },
  	{ .compatible = "qcom,pm8921-keypad" },
  	{ }
  };
  MODULE_DEVICE_TABLE(of, pm8xxx_match_table);
  
  static struct platform_driver pmic8xxx_kp_driver = {
  	.probe		= pmic8xxx_kp_probe,
  	.driver		= {
  		.name = "pm8xxx-keypad",
  		.pm = &pm8xxx_kp_pm_ops,
  		.of_match_table = pm8xxx_match_table,
  	},
  };
  module_platform_driver(pmic8xxx_kp_driver);
  
  MODULE_LICENSE("GPL v2");
  MODULE_DESCRIPTION("PMIC8XXX keypad driver");
  MODULE_VERSION("1.0");
  MODULE_ALIAS("platform:pmic8xxx_keypad");
  MODULE_AUTHOR("Trilok Soni <tsoni@codeaurora.org>");