[PATCH v4 08/10] input: keyboard: Add support for MAX7360 keypad

[Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>]

Add driver for Maxim Integrated MAX7360 keypad controller, providing
support for up to 64 keys, with a matrix of 8 columns and 8 rows.

Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
---
 drivers/input/keyboard/Kconfig          |  12 ++
 drivers/input/keyboard/Makefile         |   1 +
 drivers/input/keyboard/max7360-keypad.c | 282 ++++++++++++++++++++++++++++++++
 3 files changed, 295 insertions(+)

diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
index 721ab69e84ac..bba029f65cfa 100644
--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@ -421,6 +421,18 @@ config KEYBOARD_MAX7359
 	  To compile this driver as a module, choose M here: the
 	  module will be called max7359_keypad.
 
+config KEYBOARD_MAX7360
+	tristate "Maxim MAX7360 Key Switch Controller"
+	select INPUT_MATRIXKMAP
+	depends on I2C
+	depends on MFD_MAX7360
+	help
+	  If you say yes here you get support for the keypad controller on the
+	  Maxim MAX7360 I/O Expander.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called max7360_keypad.
+
 config KEYBOARD_MPR121
 	tristate "Freescale MPR121 Touchkey"
 	depends on I2C
diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
index 1e0721c30709..b49d32d4003d 100644
--- a/drivers/input/keyboard/Makefile
+++ b/drivers/input/keyboard/Makefile
@@ -42,6 +42,7 @@ obj-$(CONFIG_KEYBOARD_LPC32XX)		+= lpc32xx-keys.o
 obj-$(CONFIG_KEYBOARD_MAPLE)		+= maple_keyb.o
 obj-$(CONFIG_KEYBOARD_MATRIX)		+= matrix_keypad.o
 obj-$(CONFIG_KEYBOARD_MAX7359)		+= max7359_keypad.o
+obj-$(CONFIG_KEYBOARD_MAX7360)		+= max7360-keypad.o
 obj-$(CONFIG_KEYBOARD_MPR121)		+= mpr121_touchkey.o
 obj-$(CONFIG_KEYBOARD_MT6779)		+= mt6779-keypad.o
 obj-$(CONFIG_KEYBOARD_MTK_PMIC) 	+= mtk-pmic-keys.o
diff --git a/drivers/input/keyboard/max7360-keypad.c b/drivers/input/keyboard/max7360-keypad.c
new file mode 100644
index 000000000000..da7a0faea873
--- /dev/null
+++ b/drivers/input/keyboard/max7360-keypad.c
@@ -0,0 +1,282 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2024 Bootlin
+ *
+ * Author: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
+ */
+
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/input/matrix_keypad.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/max7360.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/platform_device.h>
+#include <linux/pm_wakeirq.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+struct max7360_keypad {
+	struct input_dev *input;
+	unsigned int rows;
+	unsigned int cols;
+	unsigned int debounce_ms;
+	int irq;
+	struct regmap *regmap;
+	unsigned short keycodes[MAX7360_MAX_KEY_ROWS * MAX7360_MAX_KEY_COLS];
+};
+
+static irqreturn_t max7360_keypad_irq(int irq, void *data)
+{
+	struct max7360_keypad *max7360_keypad = data;
+	unsigned int val;
+	unsigned int row, col;
+	unsigned int release;
+	unsigned int code;
+	int error;
+
+	do {
+		error = regmap_read(max7360_keypad->regmap, MAX7360_REG_KEYFIFO,
+				    &val);
+		if (error) {
+			dev_err(&max7360_keypad->input->dev,
+				"Failed to read max7360 FIFO");
+			return IRQ_NONE;
+		}
+
+		/* FIFO overflow: ignore it and get next event. */
+		if (val == MAX7360_FIFO_OVERFLOW)
+			dev_warn(&max7360_keypad->input->dev,
+				 "max7360 FIFO overflow");
+	} while (val == MAX7360_FIFO_OVERFLOW);
+
+	if (val == MAX7360_FIFO_EMPTY) {
+		dev_dbg(&max7360_keypad->input->dev,
+			"Got a spurious interrupt");
+
+		return IRQ_NONE;
+	}
+
+	row = FIELD_GET(MAX7360_FIFO_ROW, val);
+	col = FIELD_GET(MAX7360_FIFO_COL, val);
+	release = val & MAX7360_FIFO_RELEASE;
+
+	code = MATRIX_SCAN_CODE(row, col, MAX7360_ROW_SHIFT);
+
+	dev_dbg(&max7360_keypad->input->dev,
+		"key[%d:%d] %s\n", row, col, release ? "release" : "press");
+
+	input_event(max7360_keypad->input, EV_MSC, MSC_SCAN, code);
+	input_report_key(max7360_keypad->input, max7360_keypad->keycodes[code],
+			 !release);
+	input_sync(max7360_keypad->input);
+
+	return IRQ_HANDLED;
+}
+
+static int max7360_keypad_open(struct input_dev *pdev)
+{
+	struct max7360_keypad *max7360_keypad = input_get_drvdata(pdev);
+	int error;
+
+	/*
+	 * Somebody is using the device: get out of sleep.
+	 */
+	error = regmap_write_bits(max7360_keypad->regmap, MAX7360_REG_CONFIG,
+				  MAX7360_CFG_SLEEP, MAX7360_CFG_SLEEP);
+	if (error) {
+		dev_err(&max7360_keypad->input->dev,
+			"Failed to write max7360 configuration\n");
+		return error;
+	}
+
+	return 0;
+}
+
+static void max7360_keypad_close(struct input_dev *pdev)
+{
+	struct max7360_keypad *max7360_keypad = input_get_drvdata(pdev);
+	int error;
+
+	/*
+	 * Nobody is using the device anymore: go to sleep.
+	 */
+	error = regmap_write_bits(max7360_keypad->regmap, MAX7360_REG_CONFIG, MAX7360_CFG_SLEEP, 0);
+	if (error)
+		dev_err(&max7360_keypad->input->dev,
+			"Failed to write max7360 configuration\n");
+}
+
+static int max7360_keypad_hw_init(struct max7360_keypad *max7360_keypad)
+{
+	unsigned int val;
+	int error;
+
+	val = max7360_keypad->debounce_ms - MAX7360_DEBOUNCE_MIN;
+	error = regmap_write_bits(max7360_keypad->regmap, MAX7360_REG_DEBOUNCE,
+				  MAX7360_DEBOUNCE,
+				  FIELD_PREP(MAX7360_DEBOUNCE, val));
+	if (error) {
+		return dev_err_probe(&max7360_keypad->input->dev, error,
+			"Failed to write max7360 debounce configuration\n");
+	}
+
+	error = regmap_write_bits(max7360_keypad->regmap, MAX7360_REG_INTERRUPT,
+				  MAX7360_INTERRUPT_TIME_MASK,
+				  FIELD_PREP(MAX7360_INTERRUPT_TIME_MASK, 1));
+	if (error) {
+		return dev_err_probe(&max7360_keypad->input->dev, error,
+			"Failed to write max7360 keypad interrupt configuration\n");
+	}
+
+	return 0;
+}
+
+static int max7360_keypad_parse_dt(struct platform_device *pdev,
+				   struct max7360_keypad *max7360_keypad,
+				   bool *autorepeat)
+{
+	int error;
+
+	error = matrix_keypad_parse_properties(pdev->dev.parent,
+					       &max7360_keypad->rows,
+					       &max7360_keypad->cols);
+	if (error)
+		return error;
+
+	if (!max7360_keypad->rows || !max7360_keypad->cols ||
+	    max7360_keypad->rows > MAX7360_MAX_KEY_ROWS ||
+	    max7360_keypad->cols > MAX7360_MAX_KEY_COLS) {
+		dev_err(&pdev->dev,
+			"Invalid number of columns or rows (%ux%u)\n",
+			max7360_keypad->cols, max7360_keypad->rows);
+		return -EINVAL;
+	}
+
+	*autorepeat = device_property_read_bool(pdev->dev.parent, "autorepeat");
+
+	max7360_keypad->debounce_ms = MAX7360_DEBOUNCE_MIN;
+	error = device_property_read_u32(pdev->dev.parent,
+					 "keypad-debounce-delay-ms",
+					 &max7360_keypad->debounce_ms);
+	if (error == -EINVAL) {
+		dev_info(&pdev->dev, "Using default keypad-debounce-delay-ms: %u\n",
+			 max7360_keypad->debounce_ms);
+	} else if (error < 0) {
+		dev_err(&pdev->dev,
+			"Failed to read keypad-debounce-delay-ms property\n");
+		return error;
+	} else if (max7360_keypad->debounce_ms < MAX7360_DEBOUNCE_MIN ||
+		   max7360_keypad->debounce_ms > MAX7360_DEBOUNCE_MAX) {
+		dev_err(&pdev->dev,
+			"Invalid keypad-debounce-delay-ms: %u, should be between %u and %u.\n",
+			max7360_keypad->debounce_ms, MAX7360_DEBOUNCE_MIN,
+			MAX7360_DEBOUNCE_MAX);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int max7360_keypad_probe(struct platform_device *pdev)
+{
+	struct max7360_keypad *max7360_keypad;
+	struct input_dev *input;
+	bool autorepeat;
+	int error;
+	int irq;
+
+	if (!pdev->dev.parent)
+		return dev_err_probe(&pdev->dev, -ENODEV, "No parent device\n");
+
+	irq = platform_get_irq_byname(to_platform_device(pdev->dev.parent),
+				      "intk");
+	if (irq < 0)
+		return irq;
+
+	max7360_keypad = devm_kzalloc(&pdev->dev, sizeof(*max7360_keypad),
+				      GFP_KERNEL);
+	if (!max7360_keypad)
+		return -ENOMEM;
+
+	max7360_keypad->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+	if (!max7360_keypad->regmap)
+		return dev_err_probe(&pdev->dev, -ENODEV,
+				     "Could not get parent regmap\n");
+
+	error = max7360_keypad_parse_dt(pdev, max7360_keypad, &autorepeat);
+	if (error)
+		return error;
+
+	input = devm_input_allocate_device(pdev->dev.parent);
+	if (!input)
+		return -ENOMEM;
+
+	max7360_keypad->input = input;
+
+	input->id.bustype = BUS_I2C;
+	input->name = pdev->name;
+	input->open = max7360_keypad_open;
+	input->close = max7360_keypad_close;
+
+	error = matrix_keypad_build_keymap(NULL, NULL,
+					   MAX7360_MAX_KEY_ROWS,
+					   MAX7360_MAX_KEY_COLS,
+					   max7360_keypad->keycodes, input);
+	if (error)
+		return dev_err_probe(&pdev->dev, error,
+				     "Failed to build keymap\n");
+
+	input_set_capability(input, EV_MSC, MSC_SCAN);
+	if (autorepeat)
+		__set_bit(EV_REP, input->evbit);
+
+	input_set_drvdata(input, max7360_keypad);
+
+	error = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+					  max7360_keypad_irq,
+					  IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+					  "max7360-keypad", max7360_keypad);
+	if (error)
+		return dev_err_probe(&pdev->dev, error,
+				     "Failed to register interrupt\n");
+
+	error = input_register_device(input);
+	if (error)
+		return dev_err_probe(&pdev->dev, error,
+				     "Could not register input device\n");
+
+	platform_set_drvdata(pdev, max7360_keypad);
+
+	error = max7360_keypad_hw_init(max7360_keypad);
+	if (error)
+		return dev_err_probe(&pdev->dev, error,
+				     "Failed to initialize max7360 keypad\n");
+
+	device_init_wakeup(&pdev->dev, true);
+	error = dev_pm_set_wake_irq(&pdev->dev, irq);
+	if (error)
+		dev_warn(&pdev->dev, "Failed to set up wakeup irq: %d\n",
+			 error);
+
+	return 0;
+}
+
+static void max7360_keypad_remove(struct platform_device *pdev)
+{
+	dev_pm_clear_wake_irq(&pdev->dev);
+}
+
+static struct platform_driver max7360_keypad_driver = {
+	.driver = {
+		.name	= "max7360-keypad",
+	},
+	.probe		= max7360_keypad_probe,
+	.remove		= max7360_keypad_remove,
+};
+module_platform_driver(max7360_keypad_driver);
+
+MODULE_DESCRIPTION("MAX7360 Keypad driver");
+MODULE_AUTHOR("Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>");
+MODULE_LICENSE("GPL");

-- 
2.39.5