drivers/input/keyboard/tc3589x-keypad.c - kernel/msm-4.9 - Gitiles

 /*
  * 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>

 /* 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 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\n");
 		return error;
 	}

 	error = tc3589x_keypad_init_key_hardware(keypad);
 	if (error < 0) {
 		dev_err(&input->dev, "failed to configure keypad module\n");
 		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);
 }

 #ifdef CONFIG_OF
 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)\n",
 			plat->kcol, plat->krow);
 		return ERR_PTR(-EINVAL);
 	}

 	if (!of_get_property(np, "linux,keymap", &proplen)) {
 		dev_err(dev, "property linux,keymap not found\n");
 		return ERR_PTR(-ENOENT);
 	}

 	plat->no_autorepeat = of_property_read_bool(np, "linux,no-autorepeat");
 	plat->enable_wakeup = 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;
 }
 #else
 static inline const struct tc3589x_keypad_platform_data *
 tc3589x_keypad_of_probe(struct device *dev)
 {
 	return ERR_PTR(-ENODEV);
 }
 #endif


 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->pdata->keypad;
 	if (!plat) {
 		plat = tc3589x_keypad_of_probe(&pdev->dev);
 		if (IS_ERR(plat)) {
 			dev_err(&pdev->dev, "invalid keypad platform data\n");
 			return PTR_ERR(plat);
 		}
 	}

 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0)
 		return irq;

 	keypad = kzalloc(sizeof(struct tc_keypad), GFP_KERNEL);
 	input = input_allocate_device();
 	if (!keypad || !input) {
 		dev_err(&pdev->dev, "failed to allocate keypad memory\n");
 		error = -ENOMEM;
 		goto err_free_mem;
 	}

 	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\n");
 		goto err_free_mem;
 	}

 	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);

 	error = request_threaded_irq(irq, NULL,
 			tc3589x_keypad_irq, plat->irqtype,
 			"tc3589x-keypad", keypad);
 	if (error < 0) {
 		dev_err(&pdev->dev,
 				"Could not allocate irq %d,error %d\n",
 				irq, error);
 		goto err_free_mem;
 	}

 	error = input_register_device(input);
 	if (error) {
 		dev_err(&pdev->dev, "Could not register input device\n");
 		goto err_free_irq;
 	}

 	/* 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;

 err_free_irq:
 	free_irq(irq, keypad);
 err_free_mem:
 	input_free_device(input);
 	kfree(keypad);
 	return error;
 }

 static int tc3589x_keypad_remove(struct platform_device *pdev)
 {
 	struct tc_keypad *keypad = platform_get_drvdata(pdev);
 	int irq = platform_get_irq(pdev, 0);

 	if (!keypad->keypad_stopped)
 		tc3589x_keypad_disable(keypad);

 	free_irq(irq, keypad);

 	input_unregister_device(keypad->input);

 	kfree(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",
 		.owner	= THIS_MODULE,
 		.pm	= &tc3589x_keypad_dev_pm_ops,
 	},
 	.probe	= tc3589x_keypad_probe,
 	.remove	= tc3589x_keypad_remove,
 };
 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");
	/*
	* 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>

	/* 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 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\n");
	return error;
	}

	error = tc3589x_keypad_init_key_hardware(keypad);
	if (error < 0) {
	dev_err(&input->dev, "failed to configure keypad module\n");
	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);
	}

	#ifdef CONFIG_OF
	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)\n",
	plat->kcol, plat->krow);
	return ERR_PTR(-EINVAL);
	}

	if (!of_get_property(np, "linux,keymap", &proplen)) {
	dev_err(dev, "property linux,keymap not found\n");
	return ERR_PTR(-ENOENT);
	}

	plat->no_autorepeat = of_property_read_bool(np, "linux,no-autorepeat");
	plat->enable_wakeup = 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;
	}
	#else
	static inline const struct tc3589x_keypad_platform_data *
	tc3589x_keypad_of_probe(struct device *dev)
	{
	return ERR_PTR(-ENODEV);
	}
	#endif


	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->pdata->keypad;
	if (!plat) {
	plat = tc3589x_keypad_of_probe(&pdev->dev);
	if (IS_ERR(plat)) {
	dev_err(&pdev->dev, "invalid keypad platform data\n");
	return PTR_ERR(plat);
	}
	}

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
	return irq;

	keypad = kzalloc(sizeof(struct tc_keypad), GFP_KERNEL);
	input = input_allocate_device();
	if (!keypad \|\| !input) {
	dev_err(&pdev->dev, "failed to allocate keypad memory\n");
	error = -ENOMEM;
	goto err_free_mem;
	}

	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\n");
	goto err_free_mem;
	}

	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);

	error = request_threaded_irq(irq, NULL,
	tc3589x_keypad_irq, plat->irqtype,
	"tc3589x-keypad", keypad);
	if (error < 0) {
	dev_err(&pdev->dev,
	"Could not allocate irq %d,error %d\n",
	irq, error);
	goto err_free_mem;
	}

	error = input_register_device(input);
	if (error) {
	dev_err(&pdev->dev, "Could not register input device\n");
	goto err_free_irq;
	}

	/* 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;

	err_free_irq:
	free_irq(irq, keypad);
	err_free_mem:
	input_free_device(input);
	kfree(keypad);
	return error;
	}

	static int tc3589x_keypad_remove(struct platform_device *pdev)
	{
	struct tc_keypad *keypad = platform_get_drvdata(pdev);
	int irq = platform_get_irq(pdev, 0);

	if (!keypad->keypad_stopped)
	tc3589x_keypad_disable(keypad);

	free_irq(irq, keypad);

	input_unregister_device(keypad->input);

	kfree(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",
	.owner = THIS_MODULE,
	.pm = &tc3589x_keypad_dev_pm_ops,
	},
	.probe = tc3589x_keypad_probe,
	.remove = tc3589x_keypad_remove,
	};
	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");