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Release 4.11 drivers/input/keyboard/imx_keypad.c

Directory: drivers/input/keyboard
/*
 * 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);
}


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Total253100.00%1100.00%



/*
 * 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);
}


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Total219100.00%1100.00%



/*
 * 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);
	}
}


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Alberto Panizzo388100.00%1100.00%


Total388100.00%1100.00%






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;
}


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Alberto Panizzo97100.00%1100.00%


Total97100.00%1100.00%






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);
}


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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);
}


Contributors
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Alberto Panizzo5875.32%133.33%


Andreas Pretzsch1316.88%133.33%


Michael Grzeschik67.79%133.33%


Total77100.00%3100.00%






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);
}


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Alberto Panizzo6798.53%150.00%


Fabio Estevam11.47%150.00%


Total68100.00%2100.00%






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;
}


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Alberto Panizzo9482.46%133.33%


Fabio Estevam2017.54%266.67%


Total114100.00%3100.00%



#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;
}


Contributors
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Alberto Panizzo39564.02%17.69%


Liu Ying11117.99%17.69%


Fabio Estevam579.24%646.15%


Dmitry Torokhov264.21%17.69%


Michael Grzeschik121.94%17.69%


Julia Lawall111.78%17.69%


Jingoo Han40.65%17.69%


Yong Zhang10.16%17.69%


Total617100.00%13100.00%






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;
}


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Jason (Hui) Wang8997.80%133.33%


Fabio Estevam22.20%266.67%


Total91100.00%3100.00%






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;
}


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Jason (Hui) Wang8780.56%125.00%


Fabio Estevam2119.44%375.00%


Total108100.00%4100.00%



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");

Overall Contributors
PersonTokensPropCommitsCommitProp
Alberto Panizzo195178.83%14.55%


Jason (Hui) Wang1907.68%14.55%


Liu Ying1536.18%14.55%


Fabio Estevam1024.12%1045.45%


Dmitry Torokhov261.05%14.55%


Michael Grzeschik180.73%14.55%


Andreas Pretzsch130.53%14.55%


Julia Lawall110.44%14.55%


Jingoo Han50.20%29.09%


Tejun Heo30.12%14.55%


JJ Ding20.08%14.55%


Yong Zhang10.04%14.55%


Total2475100.00%22100.00%


Directory: drivers/input/keyboard



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