1 files changed, 586 insertions, 0 deletions

diff --git a/drivers/input/keyboard/imx_keypad.c b/drivers/input/keyboard/imx_keypad.c
new file mode 100644
index 000000000..e15a93619
--- /dev/null
+++ b/drivers/input/keyboard/imx_keypad.c
@@ -0,0 +1,586 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Driver for the IMX keypad port.
+// Copyright (C) 2009 Alberto Panizzo <maramaopercheseimorto@gmail.com>
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/input.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(struct timer_list *t)
+{
+	struct imx_keypad *keypad = from_timer(keypad, t, check_matrix_timer);
+	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;
+}
+
+static const struct of_device_id imx_keypad_of_match[] = {
+	{ .compatible = "fsl,imx21-kpp", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imx_keypad_of_match);
+
+static int imx_keypad_probe(struct platform_device *pdev)
+{
+	struct imx_keypad *keypad;
+	struct input_dev *input_dev;
+	int irq, error, i, row, col;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		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;
+
+	timer_setup(&keypad->check_matrix_timer,
+		    imx_keypad_check_for_events, 0);
+
+	keypad->mmio_base = devm_platform_ioremap_resource(pdev, 0);
+	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(NULL, 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_noirq_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;
+	unsigned short reg_val = readw(kbd->mmio_base + KPSR);
+
+	/* imx kbd can wake up system even clock is disabled */
+	mutex_lock(&input_dev->mutex);
+
+	if (input_device_enabled(input_dev))
+		clk_disable_unprepare(kbd->clk);
+
+	mutex_unlock(&input_dev->mutex);
+
+	if (device_may_wakeup(&pdev->dev)) {
+		if (reg_val & KBD_STAT_KPKD)
+			reg_val |= KBD_STAT_KRIE;
+		if (reg_val & KBD_STAT_KPKR)
+			reg_val |= KBD_STAT_KDIE;
+		writew(reg_val, kbd->mmio_base + KPSR);
+
+		enable_irq_wake(kbd->irq);
+	}
+
+	return 0;
+}
+
+static int __maybe_unused imx_kbd_noirq_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_device_enabled(input_dev)) {
+		ret = clk_prepare_enable(kbd->clk);
+		if (ret)
+			goto err_clk;
+	}
+
+err_clk:
+	mutex_unlock(&input_dev->mutex);
+
+	return ret;
+}
+
+static const struct dev_pm_ops imx_kbd_pm_ops = {
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx_kbd_noirq_suspend, imx_kbd_noirq_resume)
+};
+
+static struct platform_driver imx_keypad_driver = {
+	.driver		= {
+		.name	= "imx-keypad",
+		.pm	= &imx_kbd_pm_ops,
+		.of_match_table = 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");