input: MXC: add mxc-keypad driver to support the Keypad Port present in the mxc application processors family.

The MXC family of Application Processors is shipped with a Keypad Port

+ * >>Power management need to be implemented<<.

[...]
+MODULE_LICENSE("GPL v2");

Hello Alberto,

Quoted 1 line · Alberto Panizzo

The MXC family of Application Processors is shipped with a Keypad Port

would you mind to do s/MXC/IMX/ in your patch? Currently both are used but we (=Sascha and me) will try to deprecate MXC.

Quoted 2 lines

+ * >>Power management need to be implemented<<.

s/need/needs/ (or alternatively do it :-) and maybe s/<<\./.<</ ?

drivers/input/keyboard/mxc_keypad.c line 59

Quoted 5 lines

[...]

drivers/input/keyboard/mxc_keypad.c new file +3 -0

+
+	/* The matrix is stable only if no changes are detected after
+	 * MXC_KEYPAD_SCANS_FOR_STABILITY scans */

unusual format of the comment.

	/*
	 * ...
	 * ...
	 */

is the most found way in the kernel for multi-line comments.

Quoted 3 lines

[...]
+MODULE_LICENSE("GPL v2");

There is no space expected in the string passed to MODULE_LICENSE.

Quoted 2 lines

[...]
+MODULE_LICENSE("GPL v2");

There is no space expected in the string passed to MODULE_LICENSE.

Quoted 3 lines · Uwe Kleine-K?nig

Quoted 2 lines

[...]
+MODULE_LICENSE("GPL v2");

There is no space expected in the string passed to MODULE_LICENSE.

in include/linux/module.h:

/*
* The following license idents are currently accepted as indicating free
* software modules
*
* "GPL" [GNU Public License v2 or later]
* "GPL v2" [GNU Public License v2]
...

drivers/input/keyboard/mxc_keypad.c new file +8 -0

+
+/* mxc_keypad_check_for_events is the timer handler.
+ * It is executed in a non interruptible area of the kernel (Soft interrupt) */
+static void mxc_keypad_check_for_events(unsigned long data)
+{
+	struct mxc_keypad *keypad = (struct mxc_keypad *) data;
+	struct input_dev *input_dev = keypad->input_dev;
+	unsigned short matrix_volatile_state[MAX_MATRIX_KEY_COLS];

drivers/input/keyboard/mxc_keypad.c new file +22 -0

+		return;
+	}
+
+	mxc_keypad_scan_matrix(keypad, matrix_volatile_state);
+
+	state_changed = false;
+	for (i = 0; (i < MAX_MATRIX_KEY_COLS) && !state_changed; i++) {
+		if ((keypad->cols_en_mask & (1 << i)) == 0)
+			continue;
+
+		if (keypad->matrix_unstable_state[i] ^
+						matrix_volatile_state[i])
+			state_changed = true;
+	}
+
+	/* 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,

drivers/input/keyboard/mxc_keypad.c new file +118 -0

+		return;
+	}
+
+	/* If the matrix is stable as we need, fire the events and save the new
+	 * stable state.
+	 * Note, if the matrix is more stable (keypad->stable_count >
+	 * MXC_KEYPAD_SCANS_FOR_STABILITY)all events are already fired.We are in
+	 * the loop of multiple key pressure detection waiting for a change. */
+	if (keypad->stable_count == MXC_KEYPAD_SCANS_FOR_STABILITY) {
+		mxc_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) && is_zero_matrix; i++)
+		if (matrix_volatile_state[i] != 0)
+			is_zero_matrix = false;
+
+
+	if (is_zero_matrix) {
+		/* No keys are still pressed.
+		 * Enable only the KDI interrupt for future key pressures.
+		 * (clear the KDI status bit and his sync chain before) */
+		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 {
+		/* Still there are keys pressed. Schedule a rescan for multiple
+		 * key pressure detection and enable the KRI interrupt for fast
+		 * reaction to an all 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 mxc_keypad_irq_handler(int irq, void *dev_id)
+{
+	struct mxc_keypad *keypad = dev_id;
+	unsigned short reg_val;
+
+	reg_val = readw(keypad->mmio_base + KPSR);
+
+	/* Disable every keypad interrupt */
+	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);
+
+	/* 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 mxc_keypad_config(struct mxc_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 mxc_keypad_inhibit(struct mxc_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);
+	writew(reg_val, keypad->mmio_base + KPSR);
+
+	/* Colums as open drain and disable all rows */
+	writew(0xff00, keypad->mmio_base + KPCR);
+}
+

drivers/input/keyboard/mxc_keypad.c new file +21 -0

+
+	/* Enable the kpp clock */
+	clk_enable(keypad->clk);
+	mxc_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 much keys pressed for now, control pins initialisation\n");
+		goto open_err;
+	}
+
+	return 0;
+
+open_err:
+	keypad->exit_flag = true;
+	del_timer_sync(&keypad->check_matrix_timer);
+	mxc_keypad_inhibit(keypad);
+	return -EIO;
+}
+

drivers/input/keyboard/mxc_keypad.c new file +93 -0

+
+	mxc_keypad_inhibit(keypad);
+
+	/* Disable clock unit */
+	clk_disable(keypad->clk);
+}
+
+static int __devinit mxc_keypad_probe(struct platform_device *pdev)
+{
+	const struct matrix_keymap_data *keymap_data = pdev->dev.platform_data;
+	struct mxc_keypad *keypad;
+	struct input_dev *input_dev;
+	struct resource *res;
+	int irq, error, i;
+
+	if (keymap_data == NULL) {
+		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 -EINVAL;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (res == NULL) {
+		dev_err(&pdev->dev, "no I/O memory defined in platform data\n");
+		return -EINVAL;
+	}
+
+	res = request_mem_region(res->start, resource_size(res), pdev->name);
+	if (res == NULL) {
+		dev_err(&pdev->dev, "failed to request I/O memory\n");
+		return -EBUSY;
+	}
+
+	input_dev = input_allocate_device();
+	if (!input_dev) {
+		dev_err(&pdev->dev, "failed to allocate the input device\n");
+		error = -ENOMEM;
+		goto failed_rel_mem;
+	}
+
+	keypad = kzalloc(sizeof(struct mxc_keypad), GFP_KERNEL);
+	if (!keypad) {
+		dev_err(&pdev->dev, "not enough memory for driver data\n");
+		error = -ENOMEM;
+		goto failed_free_input;
+	}
+
+	keypad->input_dev = input_dev;
+	keypad->irq = irq;
+	keypad->stable_count = 0;
+	keypad->exit_flag = false;
+
+	keypad->mmio_base = ioremap(res->start, resource_size(res));
+	if (keypad->mmio_base == NULL) {
+		dev_err(&pdev->dev, "failed to remap I/O memory\n");
+		error = -ENOMEM;
+		goto failed_free_priv;
+	}
+
+	keypad->clk = clk_get(&pdev->dev, "kpp");
+	if (IS_ERR(keypad->clk)) {
+		dev_err(&pdev->dev, "failed to get keypad clock\n");
+		error = PTR_ERR(keypad->clk);
+		goto failed_unmap;
+	}
+
+	/* Search for rows and cols enabled */
+	for (i = 0; i < keymap_data->keymap_size; i++) {
+		keypad->rows_en_mask |= 1 << KEY_ROW(keymap_data->keymap[i]);
+		keypad->cols_en_mask |= 1 << KEY_COL(keymap_data->keymap[i]);
+	}
+
+	if (keypad->rows_en_mask > ((1 << MAX_MATRIX_KEY_ROWS) - 1) ||
+	   keypad->cols_en_mask > ((1 << MAX_MATRIX_KEY_COLS) - 1)) {
+		dev_err(&pdev->dev, "invalid key data (too rows or colums)\n");
+		error = -EINVAL;
+		goto failed_clock_put;
+	}
+	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);
+
+	/* Init the Input device */
+	input_dev->name = pdev->name;
+	input_dev->id.bustype = BUS_HOST;
+	input_dev->dev.parent = &pdev->dev;
+	input_dev->open = mxc_keypad_open;
+	input_dev->close = mxc_keypad_close;
+	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);

drivers/input/keyboard/mxc_keypad.c new file +87 -0

+	error = request_irq(irq, mxc_keypad_irq_handler, IRQF_DISABLED,
+			pdev->name, keypad);
+	if (error) {
+		dev_err(&pdev->dev, "failed to request IRQ\n");
+		goto failed_clock_put;
+	}
+
+	/* Register the input device */
+	error = input_register_device(input_dev);
+	if (error) {
+		dev_err(&pdev->dev, "failed to register input device\n");
+		goto failed_free_irq;
+	}
+
+	platform_set_drvdata(pdev, keypad);
+	device_init_wakeup(&pdev->dev, 1);
+
+	dev_info(&pdev->dev, "device probed\n");
+
+	return 0;
+
+failed_free_irq:
+	free_irq(irq, pdev);
+failed_clock_put:
+	clk_put(keypad->clk);
+failed_unmap:
+	iounmap(keypad->mmio_base);
+failed_free_priv:
+	kfree(keypad);
+failed_free_input:
+	input_free_device(input_dev);
+failed_rel_mem:
+	release_mem_region(res->start, resource_size(res));
+	return error;
+}
+
+static int __devexit mxc_keypad_remove(struct platform_device *pdev)
+{
+	struct mxc_keypad *keypad = platform_get_drvdata(pdev);
+	struct resource *res;
+
+	dev_dbg(&pdev->dev, ">%s\n", __func__);
+
+	platform_set_drvdata(pdev, NULL);
+
+	input_unregister_device(keypad->input_dev);
+
+	free_irq(keypad->irq, keypad);
+	clk_put(keypad->clk);
+
+	iounmap(keypad->mmio_base);
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	release_mem_region(res->start, resource_size(res));
+
+	kfree(keypad);
+
+	dev_info(&pdev->dev, "device removed\n");
+
+	return 0;
+}
+
+static struct platform_driver mxc_keypad_driver = {
+	.driver		= {
+		.name	= "mxc-keypad",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= mxc_keypad_probe,
+	.remove		= __devexit_p(mxc_keypad_remove),
+};
+
+static int __init mxc_keypad_init(void)
+{
+	return platform_driver_register(&mxc_keypad_driver);
+}
+
+static void __exit mxc_keypad_exit(void)
+{
+	platform_driver_unregister(&mxc_keypad_driver);
+}
+
+module_init(mxc_keypad_init);
+module_exit(mxc_keypad_exit);
+
+MODULE_AUTHOR("Alberto Panizzo <[email protected]>");
+MODULE_DESCRIPTION("MXC Keypad Port Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:mxc-keypad");

Signature · 1 line

1.6.3.3