[PATCH v5 09/11] input: keyboard: Add support for MAX7360 keypad

Mathieu Dubois-Briand
2025-03-18T16:26:56Z

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 | 264 ++++++++++++++++++++++++++++++++
3 files changed, 277 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..bea4621c0622
--- /dev/null
+++ b/drivers/input/keyboard/max7360-keypad.c
@@ -0,0 +1,264 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2025 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 ret;
+
+ do {
+ ret = regmap_read(max7360_keypad->regmap, MAX7360_REG_KEYFIFO, &val);
+ if (ret) {
+ 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 ret;
+
+ /*
+ * Somebody is using the device: get out of sleep.
+ */
+ ret = regmap_write_bits(max7360_keypad->regmap, MAX7360_REG_CONFIG,
+ MAX7360_CFG_SLEEP, MAX7360_CFG_SLEEP);
+ if (ret) {
+ dev_err(&max7360_keypad->input->dev,
+ "Failed to write max7360 configuration\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static void max7360_keypad_close(struct input_dev *pdev)
+{
+ struct max7360_keypad *max7360_keypad = input_get_drvdata(pdev);
+ int ret;
+
+ /*
+ * Nobody is using the device anymore: go to sleep.
+ */
+ ret = regmap_write_bits(max7360_keypad->regmap, MAX7360_REG_CONFIG, MAX7360_CFG_SLEEP, 0);
+ if (ret)
+ 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 ret;
+
+ val = max7360_keypad->debounce_ms - MAX7360_DEBOUNCE_MIN;
+ ret = regmap_write_bits(max7360_keypad->regmap, MAX7360_REG_DEBOUNCE,
+ MAX7360_DEBOUNCE,
+ FIELD_PREP(MAX7360_DEBOUNCE, val));
+ if (ret) {
+ return dev_err_probe(&max7360_keypad->input->dev, ret,
+ "Failed to write max7360 debounce configuration\n");
+ }
+
+ ret = regmap_write_bits(max7360_keypad->regmap, MAX7360_REG_INTERRUPT,
+ MAX7360_INTERRUPT_TIME_MASK,
+ FIELD_PREP(MAX7360_INTERRUPT_TIME_MASK, 1));
+ if (ret) {
+ return dev_err_probe(&max7360_keypad->input->dev, ret,
+ "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 ret;
+
+ ret = matrix_keypad_parse_properties(pdev->dev.parent, &max7360_keypad->rows,
+ &max7360_keypad->cols);
+ if (ret)
+ return ret;
+
+ 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;
+ ret = device_property_read_u32(pdev->dev.parent, "keypad-debounce-delay-ms",
+ &max7360_keypad->debounce_ms);
+ if (ret == -EINVAL) {
+ dev_info(&pdev->dev, "Using default keypad-debounce-delay-ms: %u\n",
+ max7360_keypad->debounce_ms);
+ } else if (ret < 0) {
+ dev_err(&pdev->dev,
+ "Failed to read keypad-debounce-delay-ms property\n");
+ return ret;
+ } 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 ret;
+ 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");
+
+ ret = max7360_keypad_parse_dt(pdev, max7360_keypad, &autorepeat);
+ if (ret)
+ return ret;
+
+ 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;
+
+ ret = matrix_keypad_build_keymap(NULL, NULL, MAX7360_MAX_KEY_ROWS, MAX7360_MAX_KEY_COLS,
+ max7360_keypad->keycodes, input);
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret,
+ "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);
+
+ ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, max7360_keypad_irq,
+ IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+ "max7360-keypad", max7360_keypad);
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret, "Failed to register interrupt\n");
+
+ ret = input_register_device(input);
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret, "Could not register input device\n");
+
+ platform_set_drvdata(pdev, max7360_keypad);
+
+ ret = max7360_keypad_hw_init(max7360_keypad);
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret, "Failed to initialize max7360 keypad\n");
+
+ device_init_wakeup(&pdev->dev, true);
+ ret = dev_pm_set_wake_irq(&pdev->dev, irq);
+ if (ret)
+ dev_warn(&pdev->dev, "Failed to set up wakeup irq: %d\n", ret);
+
+ 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