[deliverable/linux.git] / drivers / input / keyboard / imx_keypad.c

/*
 * Driver for the IMX keypad port.
 * Copyright (C) 2009 Alberto Panizzo <maramaopercheseimorto@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/input/matrix_keypad.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/timer.h>

/*
 * Keypad Controller registers (halfword)
 */
#define KPCR		0x00 /* Keypad Control Register */

#define KPSR		0x02 /* Keypad Status Register */
#define KBD_STAT_KPKD	(0x1 << 0) /* Key Press Interrupt Status bit (w1c) */
#define KBD_STAT_KPKR	(0x1 << 1) /* Key Release Interrupt Status bit (w1c) */
#define KBD_STAT_KDSC	(0x1 << 2) /* Key Depress Synch Chain Status bit (w1c)*/
#define KBD_STAT_KRSS	(0x1 << 3) /* Key Release Synch Status bit (w1c)*/
#define KBD_STAT_KDIE	(0x1 << 8) /* Key Depress Interrupt Enable Status bit */
#define KBD_STAT_KRIE	(0x1 << 9) /* Key Release Interrupt Enable */
#define KBD_STAT_KPPEN	(0x1 << 10) /* Keypad Clock Enable */

#define KDDR		0x04 /* Keypad Data Direction Register */
#define KPDR		0x06 /* Keypad Data Register */

#define MAX_MATRIX_KEY_ROWS	8
#define MAX_MATRIX_KEY_COLS	8
#define MATRIX_ROW_SHIFT	3

#define MAX_MATRIX_KEY_NUM	(MAX_MATRIX_KEY_ROWS * MAX_MATRIX_KEY_COLS)

struct imx_keypad {

	struct clk *clk;
	struct input_dev *input_dev;
	void __iomem *mmio_base;

	int			irq;
	struct timer_list	check_matrix_timer;

	/*
	 * The matrix is stable only if no changes are detected after
	 * IMX_KEYPAD_SCANS_FOR_STABILITY scans
	 */
#define IMX_KEYPAD_SCANS_FOR_STABILITY 3
	int			stable_count;

	bool			enabled;

	/* Masks for enabled rows/cols */
	unsigned short		rows_en_mask;
	unsigned short		cols_en_mask;

	unsigned short		keycodes[MAX_MATRIX_KEY_NUM];

	/*
	 * Matrix states:
	 * -stable: achieved after a complete debounce process.
	 * -unstable: used in the debouncing process.
	 */
	unsigned short		matrix_stable_state[MAX_MATRIX_KEY_COLS];
	unsigned short		matrix_unstable_state[MAX_MATRIX_KEY_COLS];
};

/* Scan the matrix and return the new state in *matrix_volatile_state. */
static void imx_keypad_scan_matrix(struct imx_keypad *keypad,
				  unsigned short *matrix_volatile_state)
{
	int col;
	unsigned short reg_val;

	for (col = 0; col < MAX_MATRIX_KEY_COLS; col++) {
		if ((keypad->cols_en_mask & (1 << col)) == 0)
			continue;
		/*
		 * Discharge keypad capacitance:
		 * 2. write 1s on column data.
		 * 3. configure columns as totem-pole to discharge capacitance.
		 * 4. configure columns as open-drain.
		 */
		reg_val = readw(keypad->mmio_base + KPDR);
		reg_val |= 0xff00;
		writew(reg_val, keypad->mmio_base + KPDR);

		reg_val = readw(keypad->mmio_base + KPCR);
		reg_val &= ~((keypad->cols_en_mask & 0xff) << 8);
		writew(reg_val, keypad->mmio_base + KPCR);

		udelay(2);

		reg_val = readw(keypad->mmio_base + KPCR);
		reg_val |= (keypad->cols_en_mask & 0xff) << 8;
		writew(reg_val, keypad->mmio_base + KPCR);

		/*
		 * 5. Write a single column to 0, others to 1.
		 * 6. Sample row inputs and save data.
		 * 7. Repeat steps 2 - 6 for remaining columns.
		 */
		reg_val = readw(keypad->mmio_base + KPDR);
		reg_val &= ~(1 << (8 + col));
		writew(reg_val, keypad->mmio_base + KPDR);

		/*
		 * Delay added to avoid propagating the 0 from column to row
		 * when scanning.
		 */
		udelay(5);

		/*
		 * 1s in matrix_volatile_state[col] means key pressures
		 * throw data from non enabled rows.
		 */
		reg_val = readw(keypad->mmio_base + KPDR);
		matrix_volatile_state[col] = (~reg_val) & keypad->rows_en_mask;
	}

	/*
	 * Return in standby mode:
	 * 9. write 0s to columns
	 */
	reg_val = readw(keypad->mmio_base + KPDR);
	reg_val &= 0x00ff;
	writew(reg_val, keypad->mmio_base + KPDR);
}

/*
 * Compare the new matrix state (volatile) with the stable one stored in
 * keypad->matrix_stable_state and fire events if changes are detected.
 */
static void imx_keypad_fire_events(struct imx_keypad *keypad,
				   unsigned short *matrix_volatile_state)
{
	struct input_dev *input_dev = keypad->input_dev;
	int row, col;

	for (col = 0; col < MAX_MATRIX_KEY_COLS; col++) {
		unsigned short bits_changed;
		int code;

		if ((keypad->cols_en_mask & (1 << col)) == 0)
			continue; /* Column is not enabled */

		bits_changed = keypad->matrix_stable_state[col] ^
						matrix_volatile_state[col];

		if (bits_changed == 0)
			continue; /* Column does not contain changes */

		for (row = 0; row < MAX_MATRIX_KEY_ROWS; row++) {
			if ((keypad->rows_en_mask & (1 << row)) == 0)
				continue; /* Row is not enabled */
			if ((bits_changed & (1 << row)) == 0)
				continue; /* Row does not contain changes */

			code = MATRIX_SCAN_CODE(row, col, MATRIX_ROW_SHIFT);
			input_event(input_dev, EV_MSC, MSC_SCAN, code);
			input_report_key(input_dev, keypad->keycodes[code],
				matrix_volatile_state[col] & (1 << row));
			dev_dbg(&input_dev->dev, "Event code: %d, val: %d",
				keypad->keycodes[code],
				matrix_volatile_state[col] & (1 << row));
		}
	}
	input_sync(input_dev);
}

/*
 * imx_keypad_check_for_events is the timer handler.
 */
static void imx_keypad_check_for_events(unsigned long data)
{
	struct imx_keypad *keypad = (struct imx_keypad *) data;
	unsigned short matrix_volatile_state[MAX_MATRIX_KEY_COLS];
	unsigned short reg_val;
	bool state_changed, is_zero_matrix;
	int i;

	memset(matrix_volatile_state, 0, sizeof(matrix_volatile_state));

	imx_keypad_scan_matrix(keypad, matrix_volatile_state);

	state_changed = false;
	for (i = 0; i < MAX_MATRIX_KEY_COLS; i++) {
		if ((keypad->cols_en_mask & (1 << i)) == 0)
			continue;

		if (keypad->matrix_unstable_state[i] ^ matrix_volatile_state[i]) {
			state_changed = true;
			break;
		}
	}

	/*
	 * If the matrix state is changed from the previous scan
	 *   (Re)Begin the debouncing process, saving the new state in
	 *    keypad->matrix_unstable_state.
	 * else
	 *   Increase the count of number of scans with a stable state.
	 */
	if (state_changed) {
		memcpy(keypad->matrix_unstable_state, matrix_volatile_state,
			sizeof(matrix_volatile_state));
		keypad->stable_count = 0;
	} else
		keypad->stable_count++;

	/*
	 * If the matrix is not as stable as we want reschedule scan
	 * in the near future.
	 */
	if (keypad->stable_count < IMX_KEYPAD_SCANS_FOR_STABILITY) {
		mod_timer(&keypad->check_matrix_timer,
			  jiffies + msecs_to_jiffies(10));
		return;
	}

	/*
	 * If the matrix state is stable, fire the events and save the new
	 * stable state. Note, if the matrix is kept stable for longer
	 * (keypad->stable_count > IMX_KEYPAD_SCANS_FOR_STABILITY) all
	 * events have already been generated.
	 */
	if (keypad->stable_count == IMX_KEYPAD_SCANS_FOR_STABILITY) {
		imx_keypad_fire_events(keypad, matrix_volatile_state);

		memcpy(keypad->matrix_stable_state, matrix_volatile_state,
			sizeof(matrix_volatile_state));
	}

	is_zero_matrix = true;
	for (i = 0; i < MAX_MATRIX_KEY_COLS; i++) {
		if (matrix_volatile_state[i] != 0) {
			is_zero_matrix = false;
			break;
		}
	}


	if (is_zero_matrix) {
		/*
		 * All keys have been released. Enable only the KDI
		 * interrupt for future key presses (clear the KDI
		 * status bit and its sync chain before that).
		 */
		reg_val = readw(keypad->mmio_base + KPSR);
		reg_val |= KBD_STAT_KPKD | KBD_STAT_KDSC;
		writew(reg_val, keypad->mmio_base + KPSR);

		reg_val = readw(keypad->mmio_base + KPSR);
		reg_val |= KBD_STAT_KDIE;
		reg_val &= ~KBD_STAT_KRIE;
		writew(reg_val, keypad->mmio_base + KPSR);
	} else {
		/*
		 * Some keys are still pressed. Schedule a rescan in
		 * attempt to detect multiple key presses and enable
		 * the KRI interrupt to react quickly to key release
		 * event.
		 */
		mod_timer(&keypad->check_matrix_timer,
			  jiffies + msecs_to_jiffies(60));

		reg_val = readw(keypad->mmio_base + KPSR);
		reg_val |= KBD_STAT_KPKR | KBD_STAT_KRSS;
		writew(reg_val, keypad->mmio_base + KPSR);

		reg_val = readw(keypad->mmio_base + KPSR);
		reg_val |= KBD_STAT_KRIE;
		reg_val &= ~KBD_STAT_KDIE;
		writew(reg_val, keypad->mmio_base + KPSR);
	}
}

static irqreturn_t imx_keypad_irq_handler(int irq, void *dev_id)
{
	struct imx_keypad *keypad = dev_id;
	unsigned short reg_val;

	reg_val = readw(keypad->mmio_base + KPSR);

	/* Disable both interrupt types */
	reg_val &= ~(KBD_STAT_KRIE | KBD_STAT_KDIE);
	/* Clear interrupts status bits */
	reg_val |= KBD_STAT_KPKR | KBD_STAT_KPKD;
	writew(reg_val, keypad->mmio_base + KPSR);

	if (keypad->enabled) {
		/* The matrix is supposed to be changed */
		keypad->stable_count = 0;

		/* Schedule the scanning procedure near in the future */
		mod_timer(&keypad->check_matrix_timer,
			  jiffies + msecs_to_jiffies(2));
	}

	return IRQ_HANDLED;
}

static void imx_keypad_config(struct imx_keypad *keypad)
{
	unsigned short reg_val;

	/*
	 * Include enabled rows in interrupt generation (KPCR[7:0])
	 * Configure keypad columns as open-drain (KPCR[15:8])
	 */
	reg_val = readw(keypad->mmio_base + KPCR);
	reg_val |= keypad->rows_en_mask & 0xff;		/* rows */
	reg_val |= (keypad->cols_en_mask & 0xff) << 8;	/* cols */
	writew(reg_val, keypad->mmio_base + KPCR);

	/* Write 0's to KPDR[15:8] (Colums) */
	reg_val = readw(keypad->mmio_base + KPDR);
	reg_val &= 0x00ff;
	writew(reg_val, keypad->mmio_base + KPDR);

	/* Configure columns as output, rows as input (KDDR[15:0]) */
	writew(0xff00, keypad->mmio_base + KDDR);

	/*
	 * Clear Key Depress and Key Release status bit.
	 * Clear both synchronizer chain.
	 */
	reg_val = readw(keypad->mmio_base + KPSR);
	reg_val |= KBD_STAT_KPKR | KBD_STAT_KPKD |
		   KBD_STAT_KDSC | KBD_STAT_KRSS;
	writew(reg_val, keypad->mmio_base + KPSR);

	/* Enable KDI and disable KRI (avoid false release events). */
	reg_val |= KBD_STAT_KDIE;
	reg_val &= ~KBD_STAT_KRIE;
	writew(reg_val, keypad->mmio_base + KPSR);
}

static void imx_keypad_inhibit(struct imx_keypad *keypad)
{
	unsigned short reg_val;

	/* Inhibit KDI and KRI interrupts. */
	reg_val = readw(keypad->mmio_base + KPSR);
	reg_val &= ~(KBD_STAT_KRIE | KBD_STAT_KDIE);
	reg_val |= KBD_STAT_KPKR | KBD_STAT_KPKD;
	writew(reg_val, keypad->mmio_base + KPSR);

	/* Colums as open drain and disable all rows */
	reg_val = (keypad->cols_en_mask & 0xff) << 8;
	writew(reg_val, keypad->mmio_base + KPCR);
}

static void imx_keypad_close(struct input_dev *dev)
{
	struct imx_keypad *keypad = input_get_drvdata(dev);

	dev_dbg(&dev->dev, ">%s\n", __func__);

	/* Mark keypad as being inactive */
	keypad->enabled = false;
	synchronize_irq(keypad->irq);
	del_timer_sync(&keypad->check_matrix_timer);

	imx_keypad_inhibit(keypad);

	/* Disable clock unit */
	clk_disable_unprepare(keypad->clk);
}

static int imx_keypad_open(struct input_dev *dev)
{
	struct imx_keypad *keypad = input_get_drvdata(dev);
	int error;

	dev_dbg(&dev->dev, ">%s\n", __func__);

	/* Enable the kpp clock */
	error = clk_prepare_enable(keypad->clk);
	if (error)
		return error;

	/* We became active from now */
	keypad->enabled = true;

	imx_keypad_config(keypad);

	/* Sanity control, not all the rows must be actived now. */
	if ((readw(keypad->mmio_base + KPDR) & keypad->rows_en_mask) == 0) {
		dev_err(&dev->dev,
			"too many keys pressed, control pins initialisation\n");
		goto open_err;
	}

	return 0;

open_err:
	imx_keypad_close(dev);
	return -EIO;
}

#ifdef CONFIG_OF
static const struct of_device_id imx_keypad_of_match[] = {
	{ .compatible = "fsl,imx21-kpp", },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, imx_keypad_of_match);
#endif

static int imx_keypad_probe(struct platform_device *pdev)
{
	const struct matrix_keymap_data *keymap_data =
			dev_get_platdata(&pdev->dev);
	struct imx_keypad *keypad;
	struct input_dev *input_dev;
	struct resource *res;
	int irq, error, i, row, col;

	if (!keymap_data && !pdev->dev.of_node) {
		dev_err(&pdev->dev, "no keymap defined\n");
		return -EINVAL;
	}

	irq = platform_get_irq(pdev, 0);
	if (irq < 0) {
		dev_err(&pdev->dev, "no irq defined in platform data\n");
		return irq;
	}

	input_dev = devm_input_allocate_device(&pdev->dev);
	if (!input_dev) {
		dev_err(&pdev->dev, "failed to allocate the input device\n");
		return -ENOMEM;
	}

	keypad = devm_kzalloc(&pdev->dev, sizeof(*keypad), GFP_KERNEL);
	if (!keypad) {
		dev_err(&pdev->dev, "not enough memory for driver data\n");
		return -ENOMEM;
	}

	keypad->input_dev = input_dev;
	keypad->irq = irq;
	keypad->stable_count = 0;

	setup_timer(&keypad->check_matrix_timer,
		    imx_keypad_check_for_events, (unsigned long) keypad);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	keypad->mmio_base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(keypad->mmio_base))
		return PTR_ERR(keypad->mmio_base);

	keypad->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(keypad->clk)) {
		dev_err(&pdev->dev, "failed to get keypad clock\n");
		return PTR_ERR(keypad->clk);
	}

	/* Init the Input device */
	input_dev->name = pdev->name;
	input_dev->id.bustype = BUS_HOST;
	input_dev->dev.parent = &pdev->dev;
	input_dev->open = imx_keypad_open;
	input_dev->close = imx_keypad_close;

	error = matrix_keypad_build_keymap(keymap_data, NULL,
					   MAX_MATRIX_KEY_ROWS,
					   MAX_MATRIX_KEY_COLS,
					   keypad->keycodes, input_dev);
	if (error) {
		dev_err(&pdev->dev, "failed to build keymap\n");
		return error;
	}

	/* Search for rows and cols enabled */
	for (row = 0; row < MAX_MATRIX_KEY_ROWS; row++) {
		for (col = 0; col < MAX_MATRIX_KEY_COLS; col++) {
			i = MATRIX_SCAN_CODE(row, col, MATRIX_ROW_SHIFT);
			if (keypad->keycodes[i] != KEY_RESERVED) {
				keypad->rows_en_mask |= 1 << row;
				keypad->cols_en_mask |= 1 << col;
			}
		}
	}
	dev_dbg(&pdev->dev, "enabled rows mask: %x\n", keypad->rows_en_mask);
	dev_dbg(&pdev->dev, "enabled cols mask: %x\n", keypad->cols_en_mask);

	__set_bit(EV_REP, input_dev->evbit);
	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
	input_set_drvdata(input_dev, keypad);

	/* Ensure that the keypad will stay dormant until opened */
	error = clk_prepare_enable(keypad->clk);
	if (error)
		return error;
	imx_keypad_inhibit(keypad);
	clk_disable_unprepare(keypad->clk);

	error = devm_request_irq(&pdev->dev, irq, imx_keypad_irq_handler, 0,
			    pdev->name, keypad);
	if (error) {
		dev_err(&pdev->dev, "failed to request IRQ\n");
		return error;
	}

	/* Register the input device */
	error = input_register_device(input_dev);
	if (error) {
		dev_err(&pdev->dev, "failed to register input device\n");
		return error;
	}

	platform_set_drvdata(pdev, keypad);
	device_init_wakeup(&pdev->dev, 1);

	return 0;
}

static int __maybe_unused imx_kbd_suspend(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct imx_keypad *kbd = platform_get_drvdata(pdev);
	struct input_dev *input_dev = kbd->input_dev;

	/* imx kbd can wake up system even clock is disabled */
	mutex_lock(&input_dev->mutex);

	if (input_dev->users)
		clk_disable_unprepare(kbd->clk);

	mutex_unlock(&input_dev->mutex);

	if (device_may_wakeup(&pdev->dev))
		enable_irq_wake(kbd->irq);

	return 0;
}

static int __maybe_unused imx_kbd_resume(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct imx_keypad *kbd = platform_get_drvdata(pdev);
	struct input_dev *input_dev = kbd->input_dev;
	int ret = 0;

	if (device_may_wakeup(&pdev->dev))
		disable_irq_wake(kbd->irq);

	mutex_lock(&input_dev->mutex);

	if (input_dev->users) {
		ret = clk_prepare_enable(kbd->clk);
		if (ret)
			goto err_clk;
	}

err_clk:
	mutex_unlock(&input_dev->mutex);

	return ret;
}

static SIMPLE_DEV_PM_OPS(imx_kbd_pm_ops, imx_kbd_suspend, imx_kbd_resume);

static struct platform_driver imx_keypad_driver = {
	.driver		= {
		.name	= "imx-keypad",
		.pm	= &imx_kbd_pm_ops,
		.of_match_table = of_match_ptr(imx_keypad_of_match),
	},
	.probe		= imx_keypad_probe,
};
module_platform_driver(imx_keypad_driver);

MODULE_AUTHOR("Alberto Panizzo <maramaopercheseimorto@gmail.com>");
MODULE_DESCRIPTION("IMX Keypad Port Driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:imx-keypad");
Commit	Line	Data
76cdc083 AP	1	/*
	2	* Driver for the IMX keypad port.
	3	* Copyright (C) 2009 Alberto Panizzo <maramaopercheseimorto@gmail.com>
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License version 2 as
	7	* published by the Free Software Foundation.
76cdc083 AP	8	*/
	9
	10	#include <linux/clk.h>
	11	#include <linux/delay.h>
	12	#include <linux/device.h>
	13	#include <linux/err.h>
76cdc083 AP	14	#include <linux/input/matrix_keypad.h>
	15	#include <linux/interrupt.h>
	16	#include <linux/io.h>
	17	#include <linux/jiffies.h>
	18	#include <linux/kernel.h>
	19	#include <linux/module.h>
0e14235e	20	#include <linux/of.h>
76cdc083	21	#include <linux/platform_device.h>
5a0e3ad6	22	#include <linux/slab.h>
76cdc083 AP	23	#include <linux/timer.h>
	24
	25	/*
	26	* Keypad Controller registers (halfword)
	27	*/
	28	#define KPCR 0x00 /* Keypad Control Register */
	29
	30	#define KPSR 0x02 /* Keypad Status Register */
	31	#define KBD_STAT_KPKD (0x1 << 0) /* Key Press Interrupt Status bit (w1c) */
	32	#define KBD_STAT_KPKR (0x1 << 1) /* Key Release Interrupt Status bit (w1c) */
	33	#define KBD_STAT_KDSC (0x1 << 2) /* Key Depress Synch Chain Status bit (w1c)*/
	34	#define KBD_STAT_KRSS (0x1 << 3) /* Key Release Synch Status bit (w1c)*/
	35	#define KBD_STAT_KDIE (0x1 << 8) /* Key Depress Interrupt Enable Status bit */
	36	#define KBD_STAT_KRIE (0x1 << 9) /* Key Release Interrupt Enable */
	37	#define KBD_STAT_KPPEN (0x1 << 10) /* Keypad Clock Enable */
	38
	39	#define KDDR 0x04 /* Keypad Data Direction Register */
	40	#define KPDR 0x06 /* Keypad Data Register */
	41
	42	#define MAX_MATRIX_KEY_ROWS 8
	43	#define MAX_MATRIX_KEY_COLS 8
	44	#define MATRIX_ROW_SHIFT 3
	45
	46	#define MAX_MATRIX_KEY_NUM (MAX_MATRIX_KEY_ROWS * MAX_MATRIX_KEY_COLS)
	47
	48	struct imx_keypad {
	49
	50	struct clk *clk;
	51	struct input_dev *input_dev;
	52	void __iomem *mmio_base;
	53
	54	int irq;
	55	struct timer_list check_matrix_timer;
	56
	57	/*
	58	* The matrix is stable only if no changes are detected after
	59	* IMX_KEYPAD_SCANS_FOR_STABILITY scans
	60	*/
	61	#define IMX_KEYPAD_SCANS_FOR_STABILITY 3
	62	int stable_count;
	63
	64	bool enabled;
	65
	66	/* Masks for enabled rows/cols */
	67	unsigned short rows_en_mask;
	68	unsigned short cols_en_mask;
	69
	70	unsigned short keycodes[MAX_MATRIX_KEY_NUM];
	71
	72	/*
	73	* Matrix states:
	74	* -stable: achieved after a complete debounce process.
	75	* -unstable: used in the debouncing process.
	76	*/
	77	unsigned short matrix_stable_state[MAX_MATRIX_KEY_COLS];
	78	unsigned short matrix_unstable_state[MAX_MATRIX_KEY_COLS];
	79	};
	80
	81	/* Scan the matrix and return the new state in matrix_volatile_state. /
	82	static void imx_keypad_scan_matrix(struct imx_keypad *keypad,
	83	unsigned short *matrix_volatile_state)
	84	{
	85	int col;
	86	unsigned short reg_val;
87
88	for (col = 0; col < MAX_MATRIX_KEY_COLS; col++) {
89	if ((keypad->cols_en_mask & (1 << col)) == 0)
90	continue;
91	/*
92	* Discharge keypad capacitance:
93	* 2. write 1s on column data.
94	* 3. configure columns as totem-pole to discharge capacitance.
95	* 4. configure columns as open-drain.
96	*/
97	reg_val = readw(keypad->mmio_base + KPDR);
98	reg_val \|= 0xff00;
99	writew(reg_val, keypad->mmio_base + KPDR);
100
101	reg_val = readw(keypad->mmio_base + KPCR);
102	reg_val &= ~((keypad->cols_en_mask & 0xff) << 8);
103	writew(reg_val, keypad->mmio_base + KPCR);
104
105	udelay(2);
106
107	reg_val = readw(keypad->mmio_base + KPCR);
108	reg_val \|= (keypad->cols_en_mask & 0xff) << 8;
109	writew(reg_val, keypad->mmio_base + KPCR);
110
111	/*
112	* 5. Write a single column to 0, others to 1.
113	* 6. Sample row inputs and save data.
114	* 7. Repeat steps 2 - 6 for remaining columns.
115	*/
116	reg_val = readw(keypad->mmio_base + KPDR);
117	reg_val &= ~(1 << (8 + col));
118	writew(reg_val, keypad->mmio_base + KPDR);
119
120	/*
121	* Delay added to avoid propagating the 0 from column to row
122	* when scanning.
123	*/
124	udelay(5);
125
126	/*
127	* 1s in matrix_volatile_state[col] means key pressures
128	* throw data from non enabled rows.
129	*/
130	reg_val = readw(keypad->mmio_base + KPDR);
131	matrix_volatile_state[col] = (~reg_val) & keypad->rows_en_mask;
132	}
133
134	/*
135	* Return in standby mode:
136	* 9. write 0s to columns
137	*/
138	reg_val = readw(keypad->mmio_base + KPDR);
139	reg_val &= 0x00ff;
140	writew(reg_val, keypad->mmio_base + KPDR);
141	}
142
143	/*
144	* Compare the new matrix state (volatile) with the stable one stored in
145	* keypad->matrix_stable_state and fire events if changes are detected.
146	*/
147	static void imx_keypad_fire_events(struct imx_keypad *keypad,
148	unsigned short *matrix_volatile_state)
149	{
150	struct input_dev *input_dev = keypad->input_dev;
151	int row, col;
152
153	for (col = 0; col < MAX_MATRIX_KEY_COLS; col++) {
154	unsigned short bits_changed;
155	int code;
156
157	if ((keypad->cols_en_mask & (1 << col)) == 0)
158	continue; /* Column is not enabled */
159
160	bits_changed = keypad->matrix_stable_state[col] ^
161	matrix_volatile_state[col];
162
163	if (bits_changed == 0)
164	continue; /* Column does not contain changes */
165
166	for (row = 0; row < MAX_MATRIX_KEY_ROWS; row++) {
167	if ((keypad->rows_en_mask & (1 << row)) == 0)
168	continue; /* Row is not enabled */
169	if ((bits_changed & (1 << row)) == 0)
170	continue; /* Row does not contain changes */
171
172	code = MATRIX_SCAN_CODE(row, col, MATRIX_ROW_SHIFT);
173	input_event(input_dev, EV_MSC, MSC_SCAN, code);
174	input_report_key(input_dev, keypad->keycodes[code],
175	matrix_volatile_state[col] & (1 << row));
176	dev_dbg(&input_dev->dev, "Event code: %d, val: %d",
177	keypad->keycodes[code],
178	matrix_volatile_state[col] & (1 << row));
179	}
180	}
181	input_sync(input_dev);
182	}
183
184	/*
185	* imx_keypad_check_for_events is the timer handler.
186	*/
187	static void imx_keypad_check_for_events(unsigned long data)
188	{
189	struct imx_keypad keypad = (struct imx_keypad ) data;
190	unsigned short matrix_volatile_state[MAX_MATRIX_KEY_COLS];
191	unsigned short reg_val;
192	bool state_changed, is_zero_matrix;
193	int i;
194
195	memset(matrix_volatile_state, 0, sizeof(matrix_volatile_state));
196
197	imx_keypad_scan_matrix(keypad, matrix_volatile_state);
198
199	state_changed = false;
200	for (i = 0; i < MAX_MATRIX_KEY_COLS; i++) {
201	if ((keypad->cols_en_mask & (1 << i)) == 0)
202	continue;
203
204	if (keypad->matrix_unstable_state[i] ^ matrix_volatile_state[i]) {
205	state_changed = true;
206	break;
207	}
208	}
209
210	/*
211	* If the matrix state is changed from the previous scan
212	* (Re)Begin the debouncing process, saving the new state in
213	* keypad->matrix_unstable_state.
214	* else
215	* Increase the count of number of scans with a stable state.
216	*/
217	if (state_changed) {
218	memcpy(keypad->matrix_unstable_state, matrix_volatile_state,
219	sizeof(matrix_volatile_state));
220	keypad->stable_count = 0;
221	} else
222	keypad->stable_count++;
223
224	/*
225	* If the matrix is not as stable as we want reschedule scan
226	* in the near future.
227	*/
228	if (keypad->stable_count < IMX_KEYPAD_SCANS_FOR_STABILITY) {
229	mod_timer(&keypad->check_matrix_timer,
230	jiffies + msecs_to_jiffies(10));
231	return;
232	}
233
234	/*
235	* If the matrix state is stable, fire the events and save the new
236	* stable state. Note, if the matrix is kept stable for longer
237	* (keypad->stable_count > IMX_KEYPAD_SCANS_FOR_STABILITY) all
238	* events have already been generated.
239	*/
240	if (keypad->stable_count == IMX_KEYPAD_SCANS_FOR_STABILITY) {
241	imx_keypad_fire_events(keypad, matrix_volatile_state);
242
243	memcpy(keypad->matrix_stable_state, matrix_volatile_state,
244	sizeof(matrix_volatile_state));
245	}
246
247	is_zero_matrix = true;
248	for (i = 0; i < MAX_MATRIX_KEY_COLS; i++) {
249	if (matrix_volatile_state[i] != 0) {
250	is_zero_matrix = false;
251	break;
252	}
253	}
254
255
256	if (is_zero_matrix) {
257	/*
258	* All keys have been released. Enable only the KDI
259	* interrupt for future key presses (clear the KDI
260	* status bit and its sync chain before that).
261	*/
262	reg_val = readw(keypad->mmio_base + KPSR);
263	reg_val \|= KBD_STAT_KPKD \| KBD_STAT_KDSC;
264	writew(reg_val, keypad->mmio_base + KPSR);
265
266	reg_val = readw(keypad->mmio_base + KPSR);
267	reg_val \|= KBD_STAT_KDIE;
268	reg_val &= ~KBD_STAT_KRIE;
269	writew(reg_val, keypad->mmio_base + KPSR);
270	} else {
271	/*
272	* Some keys are still pressed. Schedule a rescan in
273	* attempt to detect multiple key presses and enable
274	* the KRI interrupt to react quickly to key release
275	* event.
276	*/
277	mod_timer(&keypad->check_matrix_timer,
278	jiffies + msecs_to_jiffies(60));
279
280	reg_val = readw(keypad->mmio_base + KPSR);
281	reg_val \|= KBD_STAT_KPKR \| KBD_STAT_KRSS;
282	writew(reg_val, keypad->mmio_base + KPSR);
283
284	reg_val = readw(keypad->mmio_base + KPSR);
285	reg_val \|= KBD_STAT_KRIE;
286	reg_val &= ~KBD_STAT_KDIE;
287	writew(reg_val, keypad->mmio_base + KPSR);
288	}
289	}
290
291	static irqreturn_t imx_keypad_irq_handler(int irq, void *dev_id)
292	{
293	struct imx_keypad *keypad = dev_id;
294	unsigned short reg_val;
295
296	reg_val = readw(keypad->mmio_base + KPSR);
297
298	/* Disable both interrupt types */
299	reg_val &= ~(KBD_STAT_KRIE \| KBD_STAT_KDIE);
300	/* Clear interrupts status bits */
301	reg_val \|= KBD_STAT_KPKR \| KBD_STAT_KPKD;
302	writew(reg_val, keypad->mmio_base + KPSR);
303
304	if (keypad->enabled) {
305	/* The matrix is supposed to be changed */
306	keypad->stable_count = 0;
307
308	/* Schedule the scanning procedure near in the future */
309	mod_timer(&keypad->check_matrix_timer,
310	jiffies + msecs_to_jiffies(2));
311	}
312
313	return IRQ_HANDLED;
314	}
315
316	static void imx_keypad_config(struct imx_keypad *keypad)
317	{
318	unsigned short reg_val;
319
320	/*
321	* Include enabled rows in interrupt generation (KPCR[7:0])
322	* Configure keypad columns as open-drain (KPCR[15:8])
323	*/
324	reg_val = readw(keypad->mmio_base + KPCR);
325	reg_val \|= keypad->rows_en_mask & 0xff; /* rows */
326	reg_val \|= (keypad->cols_en_mask & 0xff) << 8; /* cols */
327	writew(reg_val, keypad->mmio_base + KPCR);
328
329	/* Write 0's to KPDR[15:8] (Colums) */
330	reg_val = readw(keypad->mmio_base + KPDR);
331	reg_val &= 0x00ff;
332	writew(reg_val, keypad->mmio_base + KPDR);
333
334	/* Configure columns as output, rows as input (KDDR[15:0]) */
335	writew(0xff00, keypad->mmio_base + KDDR);
336
337	/*
338	* Clear Key Depress and Key Release status bit.
339	* Clear both synchronizer chain.
340	*/
341	reg_val = readw(keypad->mmio_base + KPSR);
342	reg_val \|= KBD_STAT_KPKR \| KBD_STAT_KPKD \|
343	KBD_STAT_KDSC \| KBD_STAT_KRSS;
344	writew(reg_val, keypad->mmio_base + KPSR);
345
346	/* Enable KDI and disable KRI (avoid false release events). */
347	reg_val \|= KBD_STAT_KDIE;
348	reg_val &= ~KBD_STAT_KRIE;
349	writew(reg_val, keypad->mmio_base + KPSR);
350	}
351
352	static void imx_keypad_inhibit(struct imx_keypad *keypad)
353	{
354	unsigned short reg_val;
355
356	/* Inhibit KDI and KRI interrupts. */
357	reg_val = readw(keypad->mmio_base + KPSR);
358	reg_val &= ~(KBD_STAT_KRIE \| KBD_STAT_KDIE);
f35dd69b	359	reg_val \|= KBD_STAT_KPKR \| KBD_STAT_KPKD;
76cdc083 AP	360	writew(reg_val, keypad->mmio_base + KPSR);
	361
	362	/* Colums as open drain and disable all rows */
92aab960 AP	363	reg_val = (keypad->cols_en_mask & 0xff) << 8;
92aab960 AP	364	writew(reg_val, keypad->mmio_base + KPCR);
76cdc083 AP	365	}
	366
	367	static void imx_keypad_close(struct input_dev *dev)
	368	{
	369	struct imx_keypad *keypad = input_get_drvdata(dev);
	370
	371	dev_dbg(&dev->dev, ">%s\n", __func__);
	372
	373	/* Mark keypad as being inactive */
	374	keypad->enabled = false;
	375	synchronize_irq(keypad->irq);
	376	del_timer_sync(&keypad->check_matrix_timer);
	377
	378	imx_keypad_inhibit(keypad);
	379
	380	/* Disable clock unit */
a1e636e6	381	clk_disable_unprepare(keypad->clk);
76cdc083 AP	382	}
	383
	384	static int imx_keypad_open(struct input_dev *dev)
	385	{
	386	struct imx_keypad *keypad = input_get_drvdata(dev);
333fbe84	387	int error;
76cdc083 AP	388
	389	dev_dbg(&dev->dev, ">%s\n", __func__);
	390
333fbe84 FE	391	/* Enable the kpp clock */
	392	error = clk_prepare_enable(keypad->clk);
	393	if (error)
	394	return error;
	395
76cdc083 AP	396	/* We became active from now */
	397	keypad->enabled = true;
	398
76cdc083 AP	399	imx_keypad_config(keypad);
	400
	401	/* Sanity control, not all the rows must be actived now. */
	402	if ((readw(keypad->mmio_base + KPDR) & keypad->rows_en_mask) == 0) {
	403	dev_err(&dev->dev,
	404	"too many keys pressed, control pins initialisation\n");
	405	goto open_err;
	406	}
	407
	408	return 0;
	409
	410	open_err:
	411	imx_keypad_close(dev);
	412	return -EIO;
	413	}
	414
0e14235e	415	#ifdef CONFIG_OF
27ec39c0	416	static const struct of_device_id imx_keypad_of_match[] = {
0e14235e LY	417	{ .compatible = "fsl,imx21-kpp", },
	418	{ /* sentinel */ }
	419	};
	420	MODULE_DEVICE_TABLE(of, imx_keypad_of_match);
	421	#endif
	422
5298cc4c	423	static int imx_keypad_probe(struct platform_device *pdev)
76cdc083	424	{
c838cb3d JH	425	const struct matrix_keymap_data *keymap_data =
c838cb3d JH	426	dev_get_platdata(&pdev->dev);
76cdc083 AP	427	struct imx_keypad *keypad;
	428	struct input_dev *input_dev;
	429	struct resource *res;
0e14235e	430	int irq, error, i, row, col;
76cdc083	431
0e14235e	432	if (!keymap_data && !pdev->dev.of_node) {
76cdc083 AP	433	dev_err(&pdev->dev, "no keymap defined\n");
	434	return -EINVAL;
	435	}
	436
	437	irq = platform_get_irq(pdev, 0);
	438	if (irq < 0) {
	439	dev_err(&pdev->dev, "no irq defined in platform data\n");
7fb45edb	440	return irq;
76cdc083 AP	441	}
76cdc083 AP	442
da5bce19	443	input_dev = devm_input_allocate_device(&pdev->dev);
76cdc083 AP	444	if (!input_dev) {
76cdc083 AP	445	dev_err(&pdev->dev, "failed to allocate the input device\n");
da5bce19	446	return -ENOMEM;
76cdc083 AP	447	}
76cdc083 AP	448
061a5ad7	449	keypad = devm_kzalloc(&pdev->dev, sizeof(*keypad), GFP_KERNEL);
76cdc083 AP	450	if (!keypad) {
76cdc083 AP	451	dev_err(&pdev->dev, "not enough memory for driver data\n");
da5bce19	452	return -ENOMEM;
76cdc083 AP	453	}
	454
	455	keypad->input_dev = input_dev;
	456	keypad->irq = irq;
	457	keypad->stable_count = 0;
	458
	459	setup_timer(&keypad->check_matrix_timer,
	460	imx_keypad_check_for_events, (unsigned long) keypad);
	461
ef0aca7f	462	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
da5bce19 FE	463	keypad->mmio_base = devm_ioremap_resource(&pdev->dev, res);
	464	if (IS_ERR(keypad->mmio_base))
	465	return PTR_ERR(keypad->mmio_base);
76cdc083	466
da5bce19	467	keypad->clk = devm_clk_get(&pdev->dev, NULL);
76cdc083 AP	468	if (IS_ERR(keypad->clk)) {
76cdc083 AP	469	dev_err(&pdev->dev, "failed to get keypad clock\n");
da5bce19	470	return PTR_ERR(keypad->clk);
76cdc083 AP	471	}
76cdc083 AP	472
76cdc083 AP	473	/* Init the Input device */
	474	input_dev->name = pdev->name;
	475	input_dev->id.bustype = BUS_HOST;
	476	input_dev->dev.parent = &pdev->dev;
	477	input_dev->open = imx_keypad_open;
	478	input_dev->close = imx_keypad_close;
76cdc083	479
1932811f DT	480	error = matrix_keypad_build_keymap(keymap_data, NULL,
	481	MAX_MATRIX_KEY_ROWS,
	482	MAX_MATRIX_KEY_COLS,
	483	keypad->keycodes, input_dev);
	484	if (error) {
	485	dev_err(&pdev->dev, "failed to build keymap\n");
da5bce19	486	return error;
1932811f	487	}
76cdc083	488
0e14235e LY	489	/* Search for rows and cols enabled */
	490	for (row = 0; row < MAX_MATRIX_KEY_ROWS; row++) {
	491	for (col = 0; col < MAX_MATRIX_KEY_COLS; col++) {
	492	i = MATRIX_SCAN_CODE(row, col, MATRIX_ROW_SHIFT);
	493	if (keypad->keycodes[i] != KEY_RESERVED) {
	494	keypad->rows_en_mask \|= 1 << row;
	495	keypad->cols_en_mask \|= 1 << col;
	496	}
	497	}
	498	}
	499	dev_dbg(&pdev->dev, "enabled rows mask: %x\n", keypad->rows_en_mask);
	500	dev_dbg(&pdev->dev, "enabled cols mask: %x\n", keypad->cols_en_mask);
	501
1932811f	502	__set_bit(EV_REP, input_dev->evbit);
76cdc083 AP	503	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
	504	input_set_drvdata(input_dev, keypad);
	505
	506	/* Ensure that the keypad will stay dormant until opened */
e998200c FE	507	error = clk_prepare_enable(keypad->clk);
	508	if (error)
	509	return error;
76cdc083	510	imx_keypad_inhibit(keypad);
609455f4	511	clk_disable_unprepare(keypad->clk);
76cdc083	512
da5bce19	513	error = devm_request_irq(&pdev->dev, irq, imx_keypad_irq_handler, 0,
76cdc083 AP	514	pdev->name, keypad);
	515	if (error) {
	516	dev_err(&pdev->dev, "failed to request IRQ\n");
da5bce19	517	return error;
76cdc083 AP	518	}
	519
	520	/* Register the input device */
	521	error = input_register_device(input_dev);
	522	if (error) {
	523	dev_err(&pdev->dev, "failed to register input device\n");
da5bce19	524	return error;
76cdc083 AP	525	}
	526
	527	platform_set_drvdata(pdev, keypad);
	528	device_init_wakeup(&pdev->dev, 1);
	529
76cdc083 AP	530	return 0;
	531	}
	532
e179d5fa	533	static int __maybe_unused imx_kbd_suspend(struct device *dev)
81e8f2bc HW	534	{
	535	struct platform_device *pdev = to_platform_device(dev);
	536	struct imx_keypad *kbd = platform_get_drvdata(pdev);
	537	struct input_dev *input_dev = kbd->input_dev;
	538
	539	/* imx kbd can wake up system even clock is disabled */
	540	mutex_lock(&input_dev->mutex);
	541
	542	if (input_dev->users)
a1e636e6	543	clk_disable_unprepare(kbd->clk);
81e8f2bc HW	544
	545	mutex_unlock(&input_dev->mutex);
	546
	547	if (device_may_wakeup(&pdev->dev))
	548	enable_irq_wake(kbd->irq);
	549
	550	return 0;
	551	}
	552
e179d5fa	553	static int __maybe_unused imx_kbd_resume(struct device *dev)
81e8f2bc HW	554	{
	555	struct platform_device *pdev = to_platform_device(dev);
	556	struct imx_keypad *kbd = platform_get_drvdata(pdev);
	557	struct input_dev *input_dev = kbd->input_dev;
333fbe84	558	int ret = 0;
81e8f2bc HW	559
	560	if (device_may_wakeup(&pdev->dev))
	561	disable_irq_wake(kbd->irq);
	562
	563	mutex_lock(&input_dev->mutex);
	564
333fbe84 FE	565	if (input_dev->users) {
	566	ret = clk_prepare_enable(kbd->clk);
	567	if (ret)
	568	goto err_clk;
	569	}
81e8f2bc	570
333fbe84	571	err_clk:
81e8f2bc HW	572	mutex_unlock(&input_dev->mutex);
81e8f2bc HW	573
333fbe84	574	return ret;
81e8f2bc	575	}
81e8f2bc HW	576
	577	static SIMPLE_DEV_PM_OPS(imx_kbd_pm_ops, imx_kbd_suspend, imx_kbd_resume);
	578
76cdc083 AP	579	static struct platform_driver imx_keypad_driver = {
	580	.driver = {
	581	.name = "imx-keypad",
81e8f2bc	582	.pm = &imx_kbd_pm_ops,
0e14235e	583	.of_match_table = of_match_ptr(imx_keypad_of_match),
76cdc083 AP	584	},
76cdc083 AP	585	.probe = imx_keypad_probe,
76cdc083	586	};
5146c84f	587	module_platform_driver(imx_keypad_driver);
76cdc083 AP	588
	589	MODULE_AUTHOR("Alberto Panizzo <maramaopercheseimorto@gmail.com>");
	590	MODULE_DESCRIPTION("IMX Keypad Port Driver");
	591	MODULE_LICENSE("GPL v2");
	592	MODULE_ALIAS("platform:imx-keypad");