[PATCH 2/2] input: keypad: add new keypad driver for MA35D1

[mjchen <mjchen0829@gmail.com>]

From: mjchen <mjchen@nuvoton.com>

Adds a new keypad driver for the MA35D1 platform.
The driver supports key scanning and interrupt handling.

Signed-off-by: mjchen <mjchen@nuvoton.com>
---
 drivers/input/keyboard/Kconfig         |  10 +
 drivers/input/keyboard/Makefile        |   1 +
 drivers/input/keyboard/ma35d1_keypad.c | 312 +++++++++++++++++++++++++
 3 files changed, 323 insertions(+)
 create mode 100644 drivers/input/keyboard/ma35d1_keypad.c

diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
index 721ab69e84ac..ce9bd5cc13a1 100644
--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@ -797,4 +797,14 @@ config KEYBOARD_CYPRESS_SF
 	  To compile this driver as a module, choose M here: the
 	  module will be called cypress-sf.
 
+config KEYBOARD_MA35D1
+	tristate "Nuvoton MA35D1 keypad driver"
+	depends on ARCH_MA35
+	select INPUT_MATRIXKMAP
+	help
+	  Say Y here if you want to use Nuvoton MA35D1 keypad.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ma35d1-keypad.
+
 endif
diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
index 1e0721c30709..9b858cdd1b6b 100644
--- a/drivers/input/keyboard/Makefile
+++ b/drivers/input/keyboard/Makefile
@@ -70,3 +70,4 @@ obj-$(CONFIG_KEYBOARD_TEGRA)		+= tegra-kbc.o
 obj-$(CONFIG_KEYBOARD_TM2_TOUCHKEY)	+= tm2-touchkey.o
 obj-$(CONFIG_KEYBOARD_TWL4030)		+= twl4030_keypad.o
 obj-$(CONFIG_KEYBOARD_XTKBD)		+= xtkbd.o
+obj-$(CONFIG_KEYBOARD_MA35D1)		+= ma35d1_keypad.o
diff --git a/drivers/input/keyboard/ma35d1_keypad.c b/drivers/input/keyboard/ma35d1_keypad.c
new file mode 100644
index 000000000000..20b5b1b91127
--- /dev/null
+++ b/drivers/input/keyboard/ma35d1_keypad.c
@@ -0,0 +1,312 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  MA35D1 keypad driver
+ *  Copyright (C) 2024 Nuvoton Technology Corp.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/input.h>
+#include <linux/platform_device.h>
+#include <linux/input/matrix_keypad.h>
+#include <linux/clk.h>
+#include <linux/of.h>
+
+/* Keypad Interface Registers */
+#define KPI_CONF		0x00
+#define KPI_3KCONF		0x04
+#define KPI_STATUS		0x08
+#define KPI_RSTC		0x0C
+#define KPI_KEST		0x10
+#define KPI_KPE0		0x18
+#define KPI_KPE1		0x1C
+#define KPI_KRE0		0x20
+#define KPI_KRE1		0x24
+#define KPI_PRESCALDIV	0x28
+
+/* KPI_CONF - Keypad Configuration Register */
+#define KROW		GENMASK(30, 28) /* Keypad Matrix ROW number */
+#define KCOL		GENMASK(26, 24) /* Keypad Matrix COL Number */
+#define DB_CLKSEL	GENMASK(19, 16) /* De-bounce sampling cycle selection */
+#define PRESCALE	GENMASK(15, 8)  /* Row Scan Cycle Pre-scale Value */
+#define WAKEUP		BIT(5) /* Lower Power Wakeup Enable */
+#define INTEN		BIT(3) /* Key Interrupt Enable Control */
+#define RKINTEN		BIT(2) /* Release Key Interrupt Enable */
+#define PKINTEN		BIT(1) /* Press Key Interrupt Enable Control */
+#define ENKP		BIT(0) /* Keypad Scan Enable */
+
+/* KPI_STATUS - Keypad Status Register */
+#define PKEY_INT	BIT(4) /* Press key interrupt */
+#define RKEY_INT	BIT(3) /* Release key interrupt */
+#define KEY_INT		BIT(2) /* Key Interrupt */
+#define RST_3KEY	BIT(1) /* 3-Keys Reset Flag */
+#define PDWAKE		BIT(0) /* Power Down Wakeup Flag */
+
+#define DEFAULT_DEBOUNCE		1
+#define DEFAULT_PRE_SCALE		1
+#define DEFAULT_PRE_SCALEDIV	32
+
+struct ma35d1_keypad {
+	struct clk *clk;
+	struct input_dev *input_dev;
+	void __iomem *mmio_base;
+	int irq;
+	unsigned int kpi_row;
+	unsigned int kpi_col;
+	unsigned int debounce_val;
+	unsigned int pre_scale;
+	unsigned int pre_scale_divider;
+};
+
+static void ma35d1_keypad_scan_matrix(struct ma35d1_keypad *keypad,	unsigned int status)
+{
+	struct input_dev *input_dev = keypad->input_dev;
+	unsigned int i, j;
+	unsigned int row_add = 0;
+	unsigned int code;
+	unsigned int key;
+	unsigned int press_key;
+	unsigned long KeyEvent[4];
+	unsigned int row_shift = get_count_order(keypad->kpi_col);
+	unsigned short *keymap = input_dev->keycode;
+
+	/* Read key event status */
+	KeyEvent[0] = readl(keypad->mmio_base + KPI_KPE0);
+	KeyEvent[1] = readl(keypad->mmio_base + KPI_KPE1);
+	KeyEvent[2] = readl(keypad->mmio_base + KPI_KRE0);
+	KeyEvent[3] = readl(keypad->mmio_base + KPI_KRE1);
+
+	/* Clear key event status */
+	writel(KeyEvent[0], (keypad->mmio_base + KPI_KPE0));
+	writel(KeyEvent[1], (keypad->mmio_base + KPI_KPE1));
+	writel(KeyEvent[2], (keypad->mmio_base + KPI_KRE0));
+	writel(KeyEvent[3], (keypad->mmio_base + KPI_KRE1));
+
+	for (j = 0; j < 4; j++) {
+		if (KeyEvent[j] != 0) {
+			row_add = (j % 2) ? 4 : 0;
+			press_key = (j < 2) ? 1 : 0;
+
+			for (i = 0; i < 32; i++) {
+				if (KeyEvent[j] & (1<<i)) {
+					code = MATRIX_SCAN_CODE(((i/8) + row_add), (i % 8), row_shift);
+					key = keymap[code];
+
+					input_event(input_dev, EV_MSC, MSC_SCAN, code);
+					input_report_key(input_dev, key, press_key);
+				}
+			}
+		}
+	}
+
+	input_sync(input_dev);
+}
+
+static irqreturn_t ma35d1_keypad_interrupt(int irq, void *dev_id)
+{
+	struct ma35d1_keypad *keypad = dev_id;
+	unsigned int  kstatus;
+
+	kstatus = readl(keypad->mmio_base + KPI_STATUS);
+
+	if (kstatus & (PKEY_INT|RKEY_INT)) {
+		ma35d1_keypad_scan_matrix(keypad, kstatus);
+	} else {
+		if (kstatus & PDWAKE)
+			writel(PDWAKE, (keypad->mmio_base + KPI_STATUS));
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int ma35d1_keypad_open(struct input_dev *dev)
+{
+	struct ma35d1_keypad *keypad = input_get_drvdata(dev);
+	unsigned int val, config;
+
+	val = RKINTEN | PKINTEN | INTEN | ENKP;
+	val |= FIELD_PREP(KCOL, (keypad->kpi_col - 1)) | FIELD_PREP(KROW, (keypad->kpi_row - 1));
+
+	if (keypad->debounce_val > 0)
+		config = FIELD_PREP(PRESCALE, (keypad->pre_scale - 1)) |
+				 FIELD_PREP(DB_CLKSEL, keypad->debounce_val);
+	else
+		config = FIELD_PREP(PRESCALE, (keypad->pre_scale - 1));
+
+	val |= config;
+
+	writel(val, keypad->mmio_base + KPI_CONF);
+	writel((keypad->pre_scale_divider - 1),	keypad->mmio_base + KPI_PRESCALDIV);
+
+	return 0;
+}
+
+static void ma35d1_keypad_close(struct input_dev *dev)
+{
+	struct ma35d1_keypad *keypad = input_get_drvdata(dev);
+
+	clk_disable(keypad->clk);
+}
+
+static int ma35d1_keypad_probe(struct platform_device *pdev)
+{
+	struct ma35d1_keypad *keypad;
+	struct input_dev *input_dev;
+	struct resource *res;
+	int error = 0;
+
+	keypad = devm_kzalloc(&pdev->dev, sizeof(*keypad), GFP_KERNEL);
+	if (!keypad)
+		return -ENOMEM;
+
+
+	input_dev = input_allocate_device();
+	if (!input_dev) {
+		dev_err(&pdev->dev, "failed to allocate input device\n");
+		return -ENOMEM;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "failed to get I/O memory\n");
+		error = -ENXIO;
+		goto failed_free_input;
+	}
+
+	keypad->mmio_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(keypad->mmio_base)) {
+		dev_err(&pdev->dev, "failed to remap I/O memory\n");
+		return PTR_ERR(keypad->mmio_base);
+	}
+
+	keypad->irq = platform_get_irq(pdev, 0);
+	if (keypad->irq < 0) {
+		dev_err(&pdev->dev, "failed to get IRQ\n");
+		return keypad->irq;
+	}
+
+	keypad->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(keypad->clk)) {
+		dev_err(&pdev->dev, "failed to get core clk: %ld\n", PTR_ERR(keypad->clk));
+		return PTR_ERR(keypad->clk);
+	}
+
+	error = matrix_keypad_parse_properties(&pdev->dev,
+										   &(keypad->kpi_row),
+										   &(keypad->kpi_col));
+	if (error) {
+		dev_err(&pdev->dev, "failed to parse kp params\n");
+		return error;
+	}
+
+	error = matrix_keypad_build_keymap(NULL, NULL,
+									   keypad->kpi_row,
+									   keypad->kpi_col,
+									   NULL, input_dev);
+	if (error) {
+		dev_err(&pdev->dev, "failed to build keymap\n");
+		return error;
+	}
+
+	keypad->input_dev = input_dev;
+	input_dev->name = pdev->name;
+	input_dev->id.bustype = BUS_HOST;
+	input_dev->open = ma35d1_keypad_open;
+	input_dev->close = ma35d1_keypad_close;
+	input_dev->dev.parent = &pdev->dev;
+
+	if (of_property_read_u32(pdev->dev.of_node, "debounce-period", &(keypad->debounce_val)))
+		keypad->debounce_val = DEFAULT_DEBOUNCE;
+
+	if (of_property_read_u32(pdev->dev.of_node, "per-scale", &(keypad->pre_scale)))
+		keypad->pre_scale = DEFAULT_PRE_SCALE;
+
+	if (of_property_read_u32(pdev->dev.of_node, "per-scalediv", &(keypad->pre_scale_divider)))
+		keypad->pre_scale_divider = DEFAULT_PRE_SCALEDIV;
+
+	__set_bit(EV_REP, input_dev->evbit);
+	input_set_drvdata(input_dev, keypad);
+	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
+
+	error = input_register_device(input_dev);
+	if (error) {
+		dev_err(&pdev->dev, "failed to register input device\n");
+		goto failed_free_input;
+	}
+
+	error = devm_request_irq(&pdev->dev, keypad->irq,
+							 ma35d1_keypad_interrupt,
+							 IRQF_NO_SUSPEND, pdev->name, keypad);
+	if (error) {
+		dev_err(&pdev->dev, "failed to request IRQ\n");
+		goto failed_unregister_input;
+	}
+
+	platform_set_drvdata(pdev, keypad);
+	device_init_wakeup(&pdev->dev, 1);
+	clk_prepare_enable(keypad->clk);
+
+	return 0;
+
+failed_unregister_input:
+	input_unregister_device(input_dev);
+failed_free_input:
+	input_free_device(input_dev);
+	return error;
+}
+
+static void ma35d1_keypad_remove(struct platform_device *pdev)
+{
+	struct ma35d1_keypad *keypad = platform_get_drvdata(pdev);
+
+	input_unregister_device(keypad->input_dev);
+	clk_disable_unprepare(keypad->clk);
+}
+
+static int ma35d1_keypad_suspend(struct platform_device *pdev,
+									pm_message_t state)
+{
+	struct ma35d1_keypad *keypad = platform_get_drvdata(pdev);
+
+	if (device_may_wakeup(&pdev->dev)) {
+		writel(readl(keypad->mmio_base + KPI_CONF) | WAKEUP, keypad->mmio_base + KPI_CONF);
+		enable_irq_wake(keypad->irq);
+	}
+
+	return 0;
+}
+
+static int ma35d1_keypad_resume(struct platform_device *pdev)
+{
+	struct ma35d1_keypad *keypad = platform_get_drvdata(pdev);
+
+	if (device_may_wakeup(&pdev->dev)) {
+		writel(readl(keypad->mmio_base + KPI_CONF) & ~(WAKEUP),
+						keypad->mmio_base + KPI_CONF);
+		disable_irq_wake(keypad->irq);
+	}
+
+	return 0;
+}
+
+static const struct of_device_id ma35d1_kpi_of_match[] = {
+	{ .compatible = "nuvoton,ma35d1-kpi"},
+	{},
+};
+MODULE_DEVICE_TABLE(of, ma35d1_kpi_of_match);
+
+static struct platform_driver ma35d1_keypad_driver = {
+	.probe		= ma35d1_keypad_probe,
+	.remove		= ma35d1_keypad_remove,
+	.suspend	= ma35d1_keypad_suspend,
+	.resume		= ma35d1_keypad_resume,
+	.driver		= {
+		.name	= "ma35d1-kpi",
+		.of_match_table = of_match_ptr(ma35d1_kpi_of_match),
+	},
+};
+module_platform_driver(ma35d1_keypad_driver);
+
+MODULE_AUTHOR("Ming-Jen Chen");
+MODULE_DESCRIPTION("MA35D1 Keypad Driver");
+MODULE_LICENSE("GPL");
+
-- 
2.17.1