[v3,17/22] Input: adp5585: Add Analog Devices ADP5585/89 support

diff --git a/MAINTAINERS b/MAINTAINERS
index 0737dcb2e41119426f1d8fbaec829cc90ed0bf64..18838ba19e5edbbe352a470c4e177c6d24136d83 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -550,6 +550,7 @@  L:	linux-pwm@vger.kernel.org
 S:	Maintained
 F:	Documentation/devicetree/bindings/*/adi,adp5585*.yaml
 F:	drivers/gpio/gpio-adp5585.c
+F:	drivers/input/keyboard/adp5585-keys.c
 F:	drivers/mfd/adp5585.c
 F:	drivers/pwm/pwm-adp5585.c
 F:	include/linux/mfd/adp5585.h
diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
index 721ab69e84ac6586f4f19102890a15ca3fcf1910..322da0957067db77c7f66ab26a181d39c2c1d513 100644
--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@ -37,6 +37,17 @@  config KEYBOARD_ADP5520
 	  To compile this driver as a module, choose M here: the module will
 	  be called adp5520-keys.
 
+config KEYBOARD_ADP5585
+	tristate "ADP5585 and similar  I2C QWERTY Keypad and IO Expanders"
+	depends on MFD_ADP5585
+	select INPUT_MATRIXKMAP
+	help
+	  This option enables support for the KEYMAP function found in the Analog
+	  Devices ADP5585 and similar devices.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called adp5585-keys.
+
 config KEYBOARD_ADP5588
 	tristate "ADP5588/87 I2C QWERTY Keypad and IO Expander"
 	depends on I2C
diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
index 1e0721c3070968a6339a42f65a95af48364f6897..f00ec003a59aa28577ae164c0539cc5aff9579fc 100644
--- a/drivers/input/keyboard/Makefile
+++ b/drivers/input/keyboard/Makefile
@@ -7,6 +7,7 @@ 
 
 obj-$(CONFIG_KEYBOARD_ADC)		+= adc-keys.o
 obj-$(CONFIG_KEYBOARD_ADP5520)		+= adp5520-keys.o
+obj-$(CONFIG_KEYBOARD_ADP5585)		+= adp5585-keys.o
 obj-$(CONFIG_KEYBOARD_ADP5588)		+= adp5588-keys.o
 obj-$(CONFIG_KEYBOARD_ADP5589)		+= adp5589-keys.o
 obj-$(CONFIG_KEYBOARD_AMIGA)		+= amikbd.o
diff --git a/drivers/input/keyboard/adp5585-keys.c b/drivers/input/keyboard/adp5585-keys.c
new file mode 100644
index 0000000000000000000000000000000000000000..54e8fefcfab8942507245aa27931ccaf8d195b8e
--- /dev/null
+++ b/drivers/input/keyboard/adp5585-keys.c
@@ -0,0 +1,356 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Analog Devices ADP5585 Keys driver
+ *
+ * Copyright (C) 2025 Analog Devices, Inc.
+ */
+
+#include <linux/bitmap.h>
+#include <linux/device.h>
+#include <linux/find.h>
+#include <linux/input.h>
+#include <linux/input/matrix_keypad.h>
+#include <linux/mfd/adp5585.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+
+/* As needed for the matrix parsing code */
+#define ADP5589_MAX_KEYMAPSIZE		123
+
+struct adp5585_kpad_chip {
+	u8 key_ev_min;
+	u8 key_ev_max;
+	u8 max_rows;
+	u8 max_cols;
+};
+
+struct adp5585_kpad {
+	const struct adp5585_kpad_chip *info;
+	struct adp5585_ev_handler ev_handler;
+	struct input_dev *input;
+	unsigned short keycode[ADP5589_MAX_KEYMAPSIZE];
+	struct device *dev;
+	unsigned long keypad;
+	int row_shift;
+};
+
+static int adp5585_keys_validate_events(const struct adp5585_kpad *kpad,
+					const u32 *events, u32 n_events)
+{
+	unsigned int ev;
+	u32 row, col;
+
+	for (ev = 0; ev < n_events; ev++) {
+		if (events[ev] < kpad->info->key_ev_min ||
+		    events[ev] > kpad->info->key_ev_max)
+			continue;
+
+		/*
+		 * if the event is to be generated by the keymap, we need to make
+		 * sure that the pins are part of it!
+		 */
+		row = (events[ev] - 1) / kpad->info->max_cols;
+		col = (events[ev] - 1) % kpad->info->max_cols;
+
+		if (test_bit(row, &kpad->keypad) &&
+		    test_bit(col + kpad->info->max_rows, &kpad->keypad))
+			continue;
+
+		return dev_err_probe(kpad->dev, -EINVAL,
+				     "Invalid unlock/reset event(%u) not used in the keypad\n",
+				     events[ev]);
+	}
+
+	return 0;
+}
+
+static int adp5585_keys_check_special_events(const struct adp5585_dev *adp5585,
+					     const struct adp5585_kpad *kpad)
+{
+	int error;
+
+	error = adp5585_keys_validate_events(kpad, adp5585->unlock_keys,
+					     adp5585->nkeys_unlock);
+	if (error)
+		return error;
+
+	error = adp5585_keys_validate_events(kpad, adp5585->reset1_keys,
+					     adp5585->nkeys_reset1);
+	if (error)
+		return error;
+
+	return adp5585_keys_validate_events(kpad, adp5585->reset2_keys,
+					    adp5585->nkeys_reset2);
+}
+
+static void adp5585_keys_pins_free(void *data)
+{
+	struct adp5585_kpad *kpad = data;
+	struct adp5585_dev *adp5585 = dev_get_drvdata(kpad->dev->parent);
+	unsigned int pin;
+
+	for_each_set_bit(pin, &kpad->keypad, adp5585->info->n_pins)
+		clear_bit(pin, adp5585->pin_usage);
+}
+
+static int adp5585_keys_parse_fw(const struct adp5585_dev *adp5585,
+				 struct adp5585_kpad *kpad)
+{
+	struct device *dev = kpad->dev;
+	u32 cols = 0, rows = 0, pin;
+	int error, n_pins;
+
+	/*
+	 * We do not check for errors (or no value) since the input device is
+	 * only added if this property is present in the first place.
+	 */
+	n_pins = device_property_count_u32(dev, "adi,keypad-pins");
+	if (n_pins > adp5585->info->n_pins)
+		return dev_err_probe(dev, -EINVAL,
+				     "Too many keypad pins (%d) defined (max=%d)\n",
+				     n_pins, adp5585->info->n_pins);
+
+	unsigned int *keypad_pins __free(kfree) = kcalloc(n_pins, sizeof(*keypad_pins),
+							  GFP_KERNEL);
+	if (!keypad_pins)
+		return -ENOMEM;
+
+	error = device_property_read_u32_array(dev, "adi,keypad-pins",
+					       keypad_pins, n_pins);
+	if (error)
+		return error;
+
+	for (pin = 0; pin < n_pins; pin++) {
+		if (keypad_pins[pin] >= adp5585->info->n_pins) {
+			error = dev_err_probe(dev, -EINVAL,
+					      "Invalid keypad pin(%u) defined\n",
+					      keypad_pins[pin]);
+			goto out_free_map;
+		}
+
+		if (test_and_set_bit(keypad_pins[pin], adp5585->pin_usage)) {
+			error = dev_err_probe(dev, -EBUSY,
+					      "Keypad pin(%u) already used\n",
+					      keypad_pins[pin]);
+			goto out_free_map;
+		}
+
+		__set_bit(keypad_pins[pin], &kpad->keypad);
+	}
+
+	error = devm_add_action_or_reset(dev, adp5585_keys_pins_free, kpad);
+	if (error)
+		return error;
+
+	/*
+	 * Note that given that we get a mask (and the HW allows it), we
+	 * can have holes in our keypad (eg: row0, row1 and row7 enabled).
+	 * However, for the matrix parsing functions we need to pass the
+	 * number of rows/cols as the maximum row/col used plus 1. This
+	 * pretty much means we will also have holes in our SW keypad.
+	 */
+
+	rows = find_last_bit(&kpad->keypad, kpad->info->max_rows) + 1;
+	if (rows == kpad->info->max_rows + 1)
+		return dev_err_probe(dev, -EINVAL,
+				     "Now rows defined in the keypad!\n");
+
+	cols = find_last_bit(&kpad->keypad, kpad->info->max_cols + kpad->info->max_rows);
+	if (cols < kpad->info->max_rows)
+		return dev_err_probe(dev, -EINVAL,
+				     "No columns defined in the keypad!\n");
+
+	cols = cols + 1 - kpad->info->max_rows;
+
+	error = matrix_keypad_build_keymap(NULL, NULL, rows, cols,
+					   kpad->keycode, kpad->input);
+	if (error)
+		return error;
+
+	kpad->row_shift = get_count_order(cols);
+
+	if (device_property_read_bool(kpad->dev, "autorepeat"))
+		__set_bit(EV_REP, kpad->input->evbit);
+
+	return adp5585_keys_check_special_events(adp5585, kpad);
+
+out_free_map:
+	adp5585_keys_pins_free(kpad);
+	return error;
+}
+
+static int adp5585_keys_setup(const struct adp5585_dev *adp5585,
+			      struct adp5585_kpad *kpad)
+{
+	unsigned long keys_bits, start = 0, nbits = kpad->info->max_rows;
+	const struct adp5585_regs *regs = adp5585->info->regs;
+	unsigned int i = 0, max_cols = kpad->info->max_cols;
+	int error;
+
+	/*
+	 * Take care as the below assumes max_rows is always less or equal than
+	 * 8 which is true for the supported devices. If we happen to add
+	 * another device we need to make sure this still holds true. Although
+	 * adding a new device is very unlikely.
+	 */
+	do {
+		keys_bits = bitmap_read(&kpad->keypad, start, nbits);
+		if (keys_bits) {
+			error = regmap_write(adp5585->regmap, regs->pin_cfg_a + i,
+					     keys_bits);
+			if (error)
+				return error;
+		}
+
+		start += nbits;
+		if (max_cols > 8) {
+			nbits = 8;
+			max_cols -= nbits;
+		} else {
+			nbits = max_cols;
+		}
+
+		i++;
+	} while (start < kpad->info->max_rows + kpad->info->max_cols);
+
+	return 0;
+}
+
+static int adp5585_keys_ev_handle(struct device *dev, unsigned int key,
+				  unsigned int key_press)
+{
+	struct adp5585_kpad *kpad = dev_get_drvdata(dev);
+	unsigned int row, col, code;
+
+	/* make sure the event is for us */
+	if (key < kpad->info->key_ev_min || key > kpad->info->key_ev_max)
+		return -EINVAL;
+
+	/*
+	 * Unlikely but lets be on the safe side! We do not return any error
+	 * because the event was indeed for us but with some weird value. So,
+	 * we still want the caller know that the right handler was called.
+	 */
+	if (!key)
+		return 0;
+
+	row = (key - 1) / (kpad->info->max_cols);
+	col = (key - 1) % (kpad->info->max_cols);
+	code = MATRIX_SCAN_CODE(row, col, kpad->row_shift);
+
+	dev_dbg_ratelimited(kpad->dev, "report key(%d) r(%d) c(%d) code(%d)\n",
+			    key, row, col, kpad->keycode[code]);
+
+	input_report_key(kpad->input, kpad->keycode[code], key_press);
+	input_sync(kpad->input);
+
+	return 0;
+}
+
+static int adp5585_keys_probe(struct platform_device *pdev)
+{
+	const struct platform_device_id *id = platform_get_device_id(pdev);
+	struct adp5585_dev *adp5585 = dev_get_drvdata(pdev->dev.parent);
+	struct device *dev = &pdev->dev;
+	struct adp5585_kpad *kpad;
+	unsigned int revid;
+	const char *phys;
+	int error;
+
+	kpad = devm_kzalloc(dev, sizeof(*kpad), GFP_KERNEL);
+	if (!kpad)
+		return -ENOMEM;
+
+	if (!adp5585->irq)
+		return dev_err_probe(dev, -EINVAL,
+				     "IRQ is mandatory for the keypad\n");
+
+	kpad->dev = dev;
+
+	kpad->input = devm_input_allocate_device(dev);
+	if (!kpad->input)
+		return -ENOMEM;
+
+	kpad->info = (const struct adp5585_kpad_chip *)id->driver_data;
+	if (!kpad->info)
+		return -ENODEV;
+
+	error = regmap_read(adp5585->regmap, ADP5585_ID, &revid);
+	if (error)
+		return dev_err_probe(dev, error, "Failed to read device ID\n");
+
+	phys = devm_kasprintf(dev, GFP_KERNEL, "%s/input0", pdev->name);
+	if (!phys)
+		return -ENOMEM;
+
+	kpad->input->name = pdev->name;
+	kpad->input->phys = phys;
+
+	kpad->input->id.bustype = BUS_I2C;
+	kpad->input->id.vendor = 0x0001;
+	kpad->input->id.product = 0x0001;
+	kpad->input->id.version = revid & ADP5585_REV_ID_MASK;
+
+	device_set_of_node_from_dev(dev, dev->parent);
+
+	error = adp5585_keys_parse_fw(adp5585, kpad);
+	if (error)
+		return error;
+
+	error = adp5585_keys_setup(adp5585, kpad);
+	if (error)
+		return error;
+
+	platform_set_drvdata(pdev, kpad);
+	kpad->ev_handler.dev = dev;
+	kpad->ev_handler.handler = adp5585_keys_ev_handle;
+
+	error = devm_adp5585_ev_handler_add(adp5585, &kpad->ev_handler);
+	if (error)
+		return error;
+
+	error = input_register_device(kpad->input);
+	if (error)
+		return dev_err_probe(dev, error,
+				     "Failed to register input device\n");
+
+	return 0;
+}
+
+static const struct adp5585_kpad_chip adp5585_kpad_chip_info = {
+	.max_rows = 6,
+	.max_cols = 5,
+	.key_ev_min = ADP5585_ROW5_KEY_EVENT_START,
+	.key_ev_max = ADP5585_ROW5_KEY_EVENT_END,
+};
+
+static const struct adp5585_kpad_chip adp5589_kpad_chip_info = {
+	.max_rows = 8,
+	.max_cols = 11,
+	.key_ev_min = ADP5589_KEY_EVENT_START,
+	.key_ev_max = ADP5589_KEY_EVENT_END,
+};
+
+static const struct platform_device_id adp5585_keys_id_table[] = {
+	{ "adp5585-keys", (kernel_ulong_t)&adp5585_kpad_chip_info },
+	{ "adp5589-keys", (kernel_ulong_t)&adp5589_kpad_chip_info },
+	{ }
+};
+MODULE_DEVICE_TABLE(platform, adp5585_keys_id_table);
+
+static struct platform_driver adp5585_keys_driver = {
+	.driver	= {
+		.name = "adp5585-keys",
+	},
+	.probe = adp5585_keys_probe,
+	.id_table = adp5585_keys_id_table,
+};
+module_platform_driver(adp5585_keys_driver);
+
+MODULE_AUTHOR("Nuno Sá <nuno.sa@analog.com>");
+MODULE_DESCRIPTION("ADP5585 Keys Driver");
+MODULE_LICENSE("GPL");