drivers/input/keyboard/nomadik-ske-keypad.c - kernel/bruno - Git at Google

 /*
  * Copyright (C) ST-Ericsson SA 2010
  *
  * Author: Naveen Kumar G <naveen.gaddipati@stericsson.com> for ST-Ericsson
  * Author: Sundar Iyer <sundar.iyer@stericsson.com> for ST-Ericsson
  *
  * License terms:GNU General Public License (GPL) version 2
  *
  * Keypad controller driver for the SKE (Scroll Key Encoder) module used in
  * the Nomadik 8815 and Ux500 platforms.
  */

 #include <linux/platform_device.h>
 #include <linux/interrupt.h>
 #include <linux/spinlock.h>
 #include <linux/io.h>
 #include <linux/delay.h>
 #include <linux/input.h>
 #include <linux/slab.h>
 #include <linux/clk.h>
 #include <linux/module.h>

 #include <linux/platform_data/keypad-nomadik-ske.h>

 /* SKE_CR bits */
 #define SKE_KPMLT	(0x1 << 6)
 #define SKE_KPCN	(0x7 << 3)
 #define SKE_KPASEN	(0x1 << 2)
 #define SKE_KPASON	(0x1 << 7)

 /* SKE_IMSC bits */
 #define SKE_KPIMA	(0x1 << 2)

 /* SKE_ICR bits */
 #define SKE_KPICS	(0x1 << 3)
 #define SKE_KPICA	(0x1 << 2)

 /* SKE_RIS bits */
 #define SKE_KPRISA	(0x1 << 2)

 #define SKE_KEYPAD_ROW_SHIFT	3
 #define SKE_KPD_NUM_ROWS	8
 #define SKE_KPD_NUM_COLS	8

 /* keypad auto scan registers */
 #define SKE_ASR0	0x20
 #define SKE_ASR1	0x24
 #define SKE_ASR2	0x28
 #define SKE_ASR3	0x2C

 #define SKE_NUM_ASRX_REGISTERS	(4)
 #define	KEY_PRESSED_DELAY	10

 /**
  * struct ske_keypad  - data structure used by keypad driver
  * @irq:	irq no
  * @reg_base:	ske registers base address
  * @input:	pointer to input device object
  * @board:	keypad platform device
  * @keymap:	matrix scan code table for keycodes
  * @clk:	clock structure pointer
  */
 struct ske_keypad {
 	int irq;
 	void __iomem *reg_base;
 	struct input_dev *input;
 	const struct ske_keypad_platform_data *board;
 	unsigned short keymap[SKE_KPD_NUM_ROWS * SKE_KPD_NUM_COLS];
 	struct clk *clk;
 	struct clk *pclk;
 	spinlock_t ske_keypad_lock;
 };

 static void ske_keypad_set_bits(struct ske_keypad *keypad, u16 addr,
 		u8 mask, u8 data)
 {
 	u32 ret;

 	spin_lock(&keypad->ske_keypad_lock);

 	ret = readl(keypad->reg_base + addr);
 	ret &= ~mask;
 	ret |= data;
 	writel(ret, keypad->reg_base + addr);

 	spin_unlock(&keypad->ske_keypad_lock);
 }

 /*
  * ske_keypad_chip_init: init keypad controller configuration
  *
  * Enable Multi key press detection, auto scan mode
  */
 static int __init ske_keypad_chip_init(struct ske_keypad *keypad)
 {
 	u32 value;
 	int timeout = keypad->board->debounce_ms;

 	/* check SKE_RIS to be 0 */
 	while ((readl(keypad->reg_base + SKE_RIS) != 0x00000000) && timeout--)
 		cpu_relax();

 	if (!timeout)
 		return -EINVAL;

 	/*
 	 * set debounce value
 	 * keypad dbounce is configured in DBCR[15:8]
 	 * dbounce value in steps of 32/32.768 ms
 	 */
 	spin_lock(&keypad->ske_keypad_lock);
 	value = readl(keypad->reg_base + SKE_DBCR);
 	value = value & 0xff;
 	value |= ((keypad->board->debounce_ms * 32000)/32768) << 8;
 	writel(value, keypad->reg_base + SKE_DBCR);
 	spin_unlock(&keypad->ske_keypad_lock);

 	/* enable multi key detection */
 	ske_keypad_set_bits(keypad, SKE_CR, 0x0, SKE_KPMLT);

 	/*
 	 * set up the number of columns
 	 * KPCN[5:3] defines no. of keypad columns to be auto scanned
 	 */
 	value = (keypad->board->kcol - 1) << 3;
 	ske_keypad_set_bits(keypad, SKE_CR, SKE_KPCN, value);

 	/* clear keypad interrupt for auto(and pending SW) scans */
 	ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA | SKE_KPICS);

 	/* un-mask keypad interrupts */
 	ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);

 	/* enable automatic scan */
 	ske_keypad_set_bits(keypad, SKE_CR, 0x0, SKE_KPASEN);

 	return 0;
 }

 static void ske_keypad_report(struct ske_keypad *keypad, u8 status, int col)
 {
 	int row = 0, code, pos;
 	struct input_dev *input = keypad->input;
 	u32 ske_ris;
 	int key_pressed;
 	int num_of_rows;

 	/* find out the row */
 	num_of_rows = hweight8(status);
 	do {
 		pos = __ffs(status);
 		row = pos;
 		status &= ~(1 << pos);

 		code = MATRIX_SCAN_CODE(row, col, SKE_KEYPAD_ROW_SHIFT);
 		ske_ris = readl(keypad->reg_base + SKE_RIS);
 		key_pressed = ske_ris & SKE_KPRISA;

 		input_event(input, EV_MSC, MSC_SCAN, code);
 		input_report_key(input, keypad->keymap[code], key_pressed);
 		input_sync(input);
 		num_of_rows--;
 	} while (num_of_rows);
 }

 static void ske_keypad_read_data(struct ske_keypad *keypad)
 {
 	u8 status;
 	int col = 0;
 	int ske_asr, i;

 	/*
 	 * Read the auto scan registers
 	 *
 	 * Each SKE_ASRx (x=0 to x=3) contains two row values.
 	 * lower byte contains row value for column 2*x,
 	 * upper byte contains row value for column 2*x + 1
 	 */
 	for (i = 0; i < SKE_NUM_ASRX_REGISTERS; i++) {
 		ske_asr = readl(keypad->reg_base + SKE_ASR0 + (4 * i));
 		if (!ske_asr)
 			continue;

 		/* now that ASRx is zero, find out the coloumn x and row y */
 		status = ske_asr & 0xff;
 		if (status) {
 			col = i * 2;
 			ske_keypad_report(keypad, status, col);
 		}
 		status = (ske_asr & 0xff00) >> 8;
 		if (status) {
 			col = (i * 2) + 1;
 			ske_keypad_report(keypad, status, col);
 		}
 	}
 }

 static irqreturn_t ske_keypad_irq(int irq, void *dev_id)
 {
 	struct ske_keypad *keypad = dev_id;
 	int timeout = keypad->board->debounce_ms;

 	/* disable auto scan interrupt; mask the interrupt generated */
 	ske_keypad_set_bits(keypad, SKE_IMSC, ~SKE_KPIMA, 0x0);
 	ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA);

 	while ((readl(keypad->reg_base + SKE_CR) & SKE_KPASON) && --timeout)
 		cpu_relax();

 	/* SKEx registers are stable and can be read */
 	ske_keypad_read_data(keypad);

 	/* wait until raw interrupt is clear */
 	while ((readl(keypad->reg_base + SKE_RIS)) && --timeout)
 		msleep(KEY_PRESSED_DELAY);

 	/* enable auto scan interrupts */
 	ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);

 	return IRQ_HANDLED;
 }

 static int __init ske_keypad_probe(struct platform_device *pdev)
 {
 	const struct ske_keypad_platform_data *plat =
 			dev_get_platdata(&pdev->dev);
 	struct ske_keypad *keypad;
 	struct input_dev *input;
 	struct resource *res;
 	int irq;
 	int error;

 	if (!plat) {
 		dev_err(&pdev->dev, "invalid keypad platform data\n");
 		return -EINVAL;
 	}

 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0) {
 		dev_err(&pdev->dev, "failed to get keypad irq\n");
 		return -EINVAL;
 	}

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res) {
 		dev_err(&pdev->dev, "missing platform resources\n");
 		return -EINVAL;
 	}

 	keypad = kzalloc(sizeof(struct ske_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->irq = irq;
 	keypad->board = plat;
 	keypad->input = input;
 	spin_lock_init(&keypad->ske_keypad_lock);

 	if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
 		dev_err(&pdev->dev, "failed to request I/O memory\n");
 		error = -EBUSY;
 		goto err_free_mem;
 	}

 	keypad->reg_base = ioremap(res->start, resource_size(res));
 	if (!keypad->reg_base) {
 		dev_err(&pdev->dev, "failed to remap I/O memory\n");
 		error = -ENXIO;
 		goto err_free_mem_region;
 	}

 	keypad->pclk = clk_get(&pdev->dev, "apb_pclk");
 	if (IS_ERR(keypad->pclk)) {
 		dev_err(&pdev->dev, "failed to get pclk\n");
 		error = PTR_ERR(keypad->pclk);
 		goto err_iounmap;
 	}

 	keypad->clk = clk_get(&pdev->dev, NULL);
 	if (IS_ERR(keypad->clk)) {
 		dev_err(&pdev->dev, "failed to get clk\n");
 		error = PTR_ERR(keypad->clk);
 		goto err_pclk;
 	}

 	input->id.bustype = BUS_HOST;
 	input->name = "ux500-ske-keypad";
 	input->dev.parent = &pdev->dev;

 	error = matrix_keypad_build_keymap(plat->keymap_data, NULL,
 					   SKE_KPD_NUM_ROWS, SKE_KPD_NUM_COLS,
 					   keypad->keymap, input);
 	if (error) {
 		dev_err(&pdev->dev, "Failed to build keymap\n");
 		goto err_clk;
 	}

 	input_set_capability(input, EV_MSC, MSC_SCAN);
 	if (!plat->no_autorepeat)
 		__set_bit(EV_REP, input->evbit);

 	error = clk_prepare_enable(keypad->pclk);
 	if (error) {
 		dev_err(&pdev->dev, "Failed to prepare/enable pclk\n");
 		goto err_clk;
 	}

 	error = clk_prepare_enable(keypad->clk);
 	if (error) {
 		dev_err(&pdev->dev, "Failed to prepare/enable clk\n");
 		goto err_pclk_disable;
 	}


 	/* go through board initialization helpers */
 	if (keypad->board->init)
 		keypad->board->init();

 	error = ske_keypad_chip_init(keypad);
 	if (error) {
 		dev_err(&pdev->dev, "unable to init keypad hardware\n");
 		goto err_clk_disable;
 	}

 	error = request_threaded_irq(keypad->irq, NULL, ske_keypad_irq,
 				     IRQF_ONESHOT, "ske-keypad", keypad);
 	if (error) {
 		dev_err(&pdev->dev, "allocate irq %d failed\n", keypad->irq);
 		goto err_clk_disable;
 	}

 	error = input_register_device(input);
 	if (error) {
 		dev_err(&pdev->dev,
 				"unable to register input device: %d\n", error);
 		goto err_free_irq;
 	}

 	if (plat->wakeup_enable)
 		device_init_wakeup(&pdev->dev, true);

 	platform_set_drvdata(pdev, keypad);

 	return 0;

 err_free_irq:
 	free_irq(keypad->irq, keypad);
 err_clk_disable:
 	clk_disable_unprepare(keypad->clk);
 err_pclk_disable:
 	clk_disable_unprepare(keypad->pclk);
 err_clk:
 	clk_put(keypad->clk);
 err_pclk:
 	clk_put(keypad->pclk);
 err_iounmap:
 	iounmap(keypad->reg_base);
 err_free_mem_region:
 	release_mem_region(res->start, resource_size(res));
 err_free_mem:
 	input_free_device(input);
 	kfree(keypad);
 	return error;
 }

 static int ske_keypad_remove(struct platform_device *pdev)
 {
 	struct ske_keypad *keypad = platform_get_drvdata(pdev);
 	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

 	free_irq(keypad->irq, keypad);

 	input_unregister_device(keypad->input);

 	clk_disable_unprepare(keypad->clk);
 	clk_put(keypad->clk);

 	if (keypad->board->exit)
 		keypad->board->exit();

 	iounmap(keypad->reg_base);
 	release_mem_region(res->start, resource_size(res));
 	kfree(keypad);

 	return 0;
 }

 #ifdef CONFIG_PM_SLEEP
 static int ske_keypad_suspend(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct ske_keypad *keypad = platform_get_drvdata(pdev);
 	int irq = platform_get_irq(pdev, 0);

 	if (device_may_wakeup(dev))
 		enable_irq_wake(irq);
 	else
 		ske_keypad_set_bits(keypad, SKE_IMSC, ~SKE_KPIMA, 0x0);

 	return 0;
 }

 static int ske_keypad_resume(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct ske_keypad *keypad = platform_get_drvdata(pdev);
 	int irq = platform_get_irq(pdev, 0);

 	if (device_may_wakeup(dev))
 		disable_irq_wake(irq);
 	else
 		ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);

 	return 0;
 }
 #endif

 static SIMPLE_DEV_PM_OPS(ske_keypad_dev_pm_ops,
 			 ske_keypad_suspend, ske_keypad_resume);

 static struct platform_driver ske_keypad_driver = {
 	.driver = {
 		.name = "nmk-ske-keypad",
 		.pm = &ske_keypad_dev_pm_ops,
 	},
 	.remove = ske_keypad_remove,
 };

 module_platform_driver_probe(ske_keypad_driver, ske_keypad_probe);

 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Naveen Kumar <naveen.gaddipati@stericsson.com> / Sundar Iyer <sundar.iyer@stericsson.com>");
 MODULE_DESCRIPTION("Nomadik Scroll-Key-Encoder Keypad Driver");
 MODULE_ALIAS("platform:nomadik-ske-keypad");
	/*
	* Copyright (C) ST-Ericsson SA 2010
	*
	* Author: Naveen Kumar G <naveen.gaddipati@stericsson.com> for ST-Ericsson
	* Author: Sundar Iyer <sundar.iyer@stericsson.com> for ST-Ericsson
	*
	* License terms:GNU General Public License (GPL) version 2
	*
	* Keypad controller driver for the SKE (Scroll Key Encoder) module used in
	* the Nomadik 8815 and Ux500 platforms.
	*/

	#include <linux/platform_device.h>
	#include <linux/interrupt.h>
	#include <linux/spinlock.h>
	#include <linux/io.h>
	#include <linux/delay.h>
	#include <linux/input.h>
	#include <linux/slab.h>
	#include <linux/clk.h>
	#include <linux/module.h>

	#include <linux/platform_data/keypad-nomadik-ske.h>

	/* SKE_CR bits */
	#define SKE_KPMLT (0x1 << 6)
	#define SKE_KPCN (0x7 << 3)
	#define SKE_KPASEN (0x1 << 2)
	#define SKE_KPASON (0x1 << 7)

	/* SKE_IMSC bits */
	#define SKE_KPIMA (0x1 << 2)

	/* SKE_ICR bits */
	#define SKE_KPICS (0x1 << 3)
	#define SKE_KPICA (0x1 << 2)

	/* SKE_RIS bits */
	#define SKE_KPRISA (0x1 << 2)

	#define SKE_KEYPAD_ROW_SHIFT 3
	#define SKE_KPD_NUM_ROWS 8
	#define SKE_KPD_NUM_COLS 8

	/* keypad auto scan registers */
	#define SKE_ASR0 0x20
	#define SKE_ASR1 0x24
	#define SKE_ASR2 0x28
	#define SKE_ASR3 0x2C

	#define SKE_NUM_ASRX_REGISTERS (4)
	#define KEY_PRESSED_DELAY 10

	/**
	* struct ske_keypad - data structure used by keypad driver
	* @irq: irq no
	* @reg_base: ske registers base address
	* @input: pointer to input device object
	* @board: keypad platform device
	* @keymap: matrix scan code table for keycodes
	* @clk: clock structure pointer
	*/
	struct ske_keypad {
	int irq;
	void __iomem *reg_base;
	struct input_dev *input;
	const struct ske_keypad_platform_data *board;
	unsigned short keymap[SKE_KPD_NUM_ROWS * SKE_KPD_NUM_COLS];
	struct clk *clk;
	struct clk *pclk;
	spinlock_t ske_keypad_lock;
	};

	static void ske_keypad_set_bits(struct ske_keypad *keypad, u16 addr,
	u8 mask, u8 data)
	{
	u32 ret;

	spin_lock(&keypad->ske_keypad_lock);

	ret = readl(keypad->reg_base + addr);
	ret &= ~mask;
	ret \|= data;
	writel(ret, keypad->reg_base + addr);

	spin_unlock(&keypad->ske_keypad_lock);
	}

	/*
	* ske_keypad_chip_init: init keypad controller configuration
	*
	* Enable Multi key press detection, auto scan mode
	*/
	static int __init ske_keypad_chip_init(struct ske_keypad *keypad)
	{
	u32 value;
	int timeout = keypad->board->debounce_ms;

	/* check SKE_RIS to be 0 */
	while ((readl(keypad->reg_base + SKE_RIS) != 0x00000000) && timeout--)
	cpu_relax();

	if (!timeout)
	return -EINVAL;

	/*
	* set debounce value
	* keypad dbounce is configured in DBCR[15:8]
	* dbounce value in steps of 32/32.768 ms
	*/
	spin_lock(&keypad->ske_keypad_lock);
	value = readl(keypad->reg_base + SKE_DBCR);
	value = value & 0xff;
	value \|= ((keypad->board->debounce_ms * 32000)/32768) << 8;
	writel(value, keypad->reg_base + SKE_DBCR);
	spin_unlock(&keypad->ske_keypad_lock);

	/* enable multi key detection */
	ske_keypad_set_bits(keypad, SKE_CR, 0x0, SKE_KPMLT);

	/*
	* set up the number of columns
	* KPCN[5:3] defines no. of keypad columns to be auto scanned
	*/
	value = (keypad->board->kcol - 1) << 3;
	ske_keypad_set_bits(keypad, SKE_CR, SKE_KPCN, value);

	/* clear keypad interrupt for auto(and pending SW) scans */
	ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA \| SKE_KPICS);

	/* un-mask keypad interrupts */
	ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);

	/* enable automatic scan */
	ske_keypad_set_bits(keypad, SKE_CR, 0x0, SKE_KPASEN);

	return 0;
	}

	static void ske_keypad_report(struct ske_keypad *keypad, u8 status, int col)
	{
	int row = 0, code, pos;
	struct input_dev *input = keypad->input;
	u32 ske_ris;
	int key_pressed;
	int num_of_rows;

	/* find out the row */
	num_of_rows = hweight8(status);
	do {
	pos = __ffs(status);
	row = pos;
	status &= ~(1 << pos);

	code = MATRIX_SCAN_CODE(row, col, SKE_KEYPAD_ROW_SHIFT);
	ske_ris = readl(keypad->reg_base + SKE_RIS);
	key_pressed = ske_ris & SKE_KPRISA;

	input_event(input, EV_MSC, MSC_SCAN, code);
	input_report_key(input, keypad->keymap[code], key_pressed);
	input_sync(input);
	num_of_rows--;
	} while (num_of_rows);
	}

	static void ske_keypad_read_data(struct ske_keypad *keypad)
	{
	u8 status;
	int col = 0;
	int ske_asr, i;

	/*
	* Read the auto scan registers
	*
	* Each SKE_ASRx (x=0 to x=3) contains two row values.
	* lower byte contains row value for column 2*x,
	* upper byte contains row value for column 2*x + 1
	*/
	for (i = 0; i < SKE_NUM_ASRX_REGISTERS; i++) {
	ske_asr = readl(keypad->reg_base + SKE_ASR0 + (4 * i));
	if (!ske_asr)
	continue;

	/* now that ASRx is zero, find out the coloumn x and row y */
	status = ske_asr & 0xff;
	if (status) {
	col = i * 2;
	ske_keypad_report(keypad, status, col);
	}
	status = (ske_asr & 0xff00) >> 8;
	if (status) {
	col = (i * 2) + 1;
	ske_keypad_report(keypad, status, col);
	}
	}
	}

	static irqreturn_t ske_keypad_irq(int irq, void *dev_id)
	{
	struct ske_keypad *keypad = dev_id;
	int timeout = keypad->board->debounce_ms;

	/* disable auto scan interrupt; mask the interrupt generated */
	ske_keypad_set_bits(keypad, SKE_IMSC, ~SKE_KPIMA, 0x0);
	ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA);

	while ((readl(keypad->reg_base + SKE_CR) & SKE_KPASON) && --timeout)
	cpu_relax();

	/* SKEx registers are stable and can be read */
	ske_keypad_read_data(keypad);

	/* wait until raw interrupt is clear */
	while ((readl(keypad->reg_base + SKE_RIS)) && --timeout)
	msleep(KEY_PRESSED_DELAY);

	/* enable auto scan interrupts */
	ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);

	return IRQ_HANDLED;
	}

	static int __init ske_keypad_probe(struct platform_device *pdev)
	{
	const struct ske_keypad_platform_data *plat =
	dev_get_platdata(&pdev->dev);
	struct ske_keypad *keypad;
	struct input_dev *input;
	struct resource *res;
	int irq;
	int error;

	if (!plat) {
	dev_err(&pdev->dev, "invalid keypad platform data\n");
	return -EINVAL;
	}

	irq = platform_get_irq(pdev, 0);
	if (irq < 0) {
	dev_err(&pdev->dev, "failed to get keypad irq\n");
	return -EINVAL;
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
	dev_err(&pdev->dev, "missing platform resources\n");
	return -EINVAL;
	}

	keypad = kzalloc(sizeof(struct ske_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->irq = irq;
	keypad->board = plat;
	keypad->input = input;
	spin_lock_init(&keypad->ske_keypad_lock);

	if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
	dev_err(&pdev->dev, "failed to request I/O memory\n");
	error = -EBUSY;
	goto err_free_mem;
	}

	keypad->reg_base = ioremap(res->start, resource_size(res));
	if (!keypad->reg_base) {
	dev_err(&pdev->dev, "failed to remap I/O memory\n");
	error = -ENXIO;
	goto err_free_mem_region;
	}

	keypad->pclk = clk_get(&pdev->dev, "apb_pclk");
	if (IS_ERR(keypad->pclk)) {
	dev_err(&pdev->dev, "failed to get pclk\n");
	error = PTR_ERR(keypad->pclk);
	goto err_iounmap;
	}

	keypad->clk = clk_get(&pdev->dev, NULL);
	if (IS_ERR(keypad->clk)) {
	dev_err(&pdev->dev, "failed to get clk\n");
	error = PTR_ERR(keypad->clk);
	goto err_pclk;
	}

	input->id.bustype = BUS_HOST;
	input->name = "ux500-ske-keypad";
	input->dev.parent = &pdev->dev;

	error = matrix_keypad_build_keymap(plat->keymap_data, NULL,
	SKE_KPD_NUM_ROWS, SKE_KPD_NUM_COLS,
	keypad->keymap, input);
	if (error) {
	dev_err(&pdev->dev, "Failed to build keymap\n");
	goto err_clk;
	}

	input_set_capability(input, EV_MSC, MSC_SCAN);
	if (!plat->no_autorepeat)
	__set_bit(EV_REP, input->evbit);

	error = clk_prepare_enable(keypad->pclk);
	if (error) {
	dev_err(&pdev->dev, "Failed to prepare/enable pclk\n");
	goto err_clk;
	}

	error = clk_prepare_enable(keypad->clk);
	if (error) {
	dev_err(&pdev->dev, "Failed to prepare/enable clk\n");
	goto err_pclk_disable;
	}


	/* go through board initialization helpers */
	if (keypad->board->init)
	keypad->board->init();

	error = ske_keypad_chip_init(keypad);
	if (error) {
	dev_err(&pdev->dev, "unable to init keypad hardware\n");
	goto err_clk_disable;
	}

	error = request_threaded_irq(keypad->irq, NULL, ske_keypad_irq,
	IRQF_ONESHOT, "ske-keypad", keypad);
	if (error) {
	dev_err(&pdev->dev, "allocate irq %d failed\n", keypad->irq);
	goto err_clk_disable;
	}

	error = input_register_device(input);
	if (error) {
	dev_err(&pdev->dev,
	"unable to register input device: %d\n", error);
	goto err_free_irq;
	}

	if (plat->wakeup_enable)
	device_init_wakeup(&pdev->dev, true);

	platform_set_drvdata(pdev, keypad);

	return 0;

	err_free_irq:
	free_irq(keypad->irq, keypad);
	err_clk_disable:
	clk_disable_unprepare(keypad->clk);
	err_pclk_disable:
	clk_disable_unprepare(keypad->pclk);
	err_clk:
	clk_put(keypad->clk);
	err_pclk:
	clk_put(keypad->pclk);
	err_iounmap:
	iounmap(keypad->reg_base);
	err_free_mem_region:
	release_mem_region(res->start, resource_size(res));
	err_free_mem:
	input_free_device(input);
	kfree(keypad);
	return error;
	}

	static int ske_keypad_remove(struct platform_device *pdev)
	{
	struct ske_keypad *keypad = platform_get_drvdata(pdev);
	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	free_irq(keypad->irq, keypad);

	input_unregister_device(keypad->input);

	clk_disable_unprepare(keypad->clk);
	clk_put(keypad->clk);

	if (keypad->board->exit)
	keypad->board->exit();

	iounmap(keypad->reg_base);
	release_mem_region(res->start, resource_size(res));
	kfree(keypad);

	return 0;
	}

	#ifdef CONFIG_PM_SLEEP
	static int ske_keypad_suspend(struct device *dev)
	{
	struct platform_device *pdev = to_platform_device(dev);
	struct ske_keypad *keypad = platform_get_drvdata(pdev);
	int irq = platform_get_irq(pdev, 0);

	if (device_may_wakeup(dev))
	enable_irq_wake(irq);
	else
	ske_keypad_set_bits(keypad, SKE_IMSC, ~SKE_KPIMA, 0x0);

	return 0;
	}

	static int ske_keypad_resume(struct device *dev)
	{
	struct platform_device *pdev = to_platform_device(dev);
	struct ske_keypad *keypad = platform_get_drvdata(pdev);
	int irq = platform_get_irq(pdev, 0);

	if (device_may_wakeup(dev))
	disable_irq_wake(irq);
	else
	ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);

	return 0;
	}
	#endif

	static SIMPLE_DEV_PM_OPS(ske_keypad_dev_pm_ops,
	ske_keypad_suspend, ske_keypad_resume);

	static struct platform_driver ske_keypad_driver = {
	.driver = {
	.name = "nmk-ske-keypad",
	.pm = &ske_keypad_dev_pm_ops,
	},
	.remove = ske_keypad_remove,
	};

	module_platform_driver_probe(ske_keypad_driver, ske_keypad_probe);

	MODULE_LICENSE("GPL v2");
	MODULE_AUTHOR("Naveen Kumar <naveen.gaddipati@stericsson.com> / Sundar Iyer <sundar.iyer@stericsson.com>");
	MODULE_DESCRIPTION("Nomadik Scroll-Key-Encoder Keypad Driver");
	MODULE_ALIAS("platform:nomadik-ske-keypad");