Subject: [PATCH v12 2/3] drivers: input: keyboard: Add mtk keypad driver

From: Fengping Yu <[email-masked]>
Date: Fri, 29 May 2020 09:56:20 +0800

From: "fengping.yu" <[email-masked]>

This adds matrix keypad support for Mediatek SoCs.

Signed-off-by: fengping.yu <[email-masked]>
---
 drivers/input/keyboard/Kconfig   |  11 ++
 drivers/input/keyboard/Makefile  |   1 +
 drivers/input/keyboard/mtk-kpd.c | 205 +++++++++++++++++++++++++++++++
 3 files changed, 217 insertions(+)
 create mode 100644 drivers/input/keyboard/mtk-kpd.c

diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
index 28de965a08d5..0803668bfa36 100644
--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@ -782,6 +782,17 @@ config KEYBOARD_BCM
 	  To compile this driver as a module, choose M here: the
 	  module will be called bcm-keypad.
 
+config KEYBOARD_MTK_KPD
+	tristate "MediaTek Keypad Support"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	select REGMAP_MMIO
+	select INPUT_MATRIXKMAP
+	help
+	  Say Y here if you want to use the keypad on MediaTek SoCs.
+	  If unsure, say N.
+	  To compile this driver as a module, choose M here: the
+	  module will be called mtk-kpd.
+
 config KEYBOARD_MTK_PMIC
 	tristate "MediaTek PMIC keys support"
 	depends on MFD_MT6397
diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
index 1d689fdd5c00..6c9d852c377e 100644
--- a/drivers/input/keyboard/Makefile
+++ b/drivers/input/keyboard/Makefile
@@ -43,6 +43,7 @@ obj-$(CONFIG_KEYBOARD_MATRIX)		+= matrix_keypad.o
 obj-$(CONFIG_KEYBOARD_MAX7359)		+= max7359_keypad.o
 obj-$(CONFIG_KEYBOARD_MCS)		+= mcs_touchkey.o
 obj-$(CONFIG_KEYBOARD_MPR121)		+= mpr121_touchkey.o
+obj-$(CONFIG_KEYBOARD_MTK_KPD)		+= mtk-kpd.o
 obj-$(CONFIG_KEYBOARD_MTK_PMIC) 	+= mtk-pmic-keys.o
 obj-$(CONFIG_KEYBOARD_NEWTON)		+= newtonkbd.o
 obj-$(CONFIG_KEYBOARD_NOMADIK)		+= nomadik-ske-keypad.o
diff --git a/drivers/input/keyboard/mtk-kpd.c b/drivers/input/keyboard/mtk-kpd.c
new file mode 100644
index 000000000000..0a6b8e2530bc
--- /dev/null
+++ b/drivers/input/keyboard/mtk-kpd.c
@@ -0,0 +1,205 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 MediaTek Inc.
+ * Author Terry Chang <[email-masked]>
+ */
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/input/matrix_keypad.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#define MTK_KPD_NAME		"mtk-kpd"
+#define MTK_KPD_MEM		0x0004
+#define MTK_KPD_DEBOUNCE	0x0018
+#define MTK_KPD_DEBOUNCE_MASK	GENMASK(13, 0)
+#define MTK_KPD_DEBOUNCE_MAX_US	256000
+#define MTK_KPD_NUM_MEMS	5
+#define MTK_KPD_NUM_BITS	136	/* 4*32+8 MEM5 only use 8 BITS */
+
+struct mtk_keypad {
+	struct regmap *regmap;
+	struct input_dev *input_dev;
+	struct clk *clk;
+	void __iomem *base;
+	u32 n_rows;
+	u32 n_cols;
+	DECLARE_BITMAP(keymap_state, MTK_KPD_NUM_BITS);
+};
+
+static const struct regmap_config keypad_regmap_cfg = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = sizeof(u32),
+	.max_register = 36,
+};
+
+static irqreturn_t kpd_irq_handler(int irq, void *dev_id)
+{
+	struct mtk_keypad *keypad = dev_id;
+	unsigned short *keycode = keypad->input_dev->keycode;
+	DECLARE_BITMAP(new_state, MTK_KPD_NUM_BITS);
+	DECLARE_BITMAP(change, MTK_KPD_NUM_BITS);
+	int bit_nr;
+	int pressed;
+	unsigned short code;
+
+	regmap_raw_read(keypad->regmap, MTK_KPD_MEM,
+			new_state, MTK_KPD_NUM_MEMS);
+
+	bitmap_xor(change, new_state, keypad->keymap_state, MTK_KPD_NUM_BITS);
+
+	for_each_set_bit(bit_nr, change, MTK_KPD_NUM_BITS) {
+		/* 1: not pressed, 0: pressed */
+		pressed = !test_bit(bit_nr, new_state);
+		dev_dbg(&keypad->input_dev->dev, "%s",
+			pressed ? "pressed" : "released");
+
+		/* 32bit register only use low 16bit as keypad mem register */
+		code = keycode[bit_nr - 16 * (BITS_TO_U32(bit_nr) - 1)];
+
+		input_report_key(keypad->input_dev, code, pressed);
+		input_sync(keypad->input_dev);
+
+		dev_dbg(&keypad->input_dev->dev,
+			"report Linux keycode = %d\n", code);
+	}
+
+	bitmap_copy(keypad->keymap_state, new_state, MTK_KPD_NUM_BITS);
+
+	return IRQ_HANDLED;
+}
+
+static void kpd_clk_disable(void *data)
+{
+	clk_disable_unprepare(data);
+}
+
+static int kpd_pdrv_probe(struct platform_device *pdev)
+{
+	struct mtk_keypad *keypad;
+	unsigned int irq;
+	u32 debounce;
+	bool wakeup;
+	int ret;
+
+	keypad = devm_kzalloc(&pdev->dev, sizeof(*keypad), GFP_KERNEL);
+	if (!keypad)
+		return -ENOMEM;
+
+	keypad->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(keypad->base))
+		return PTR_ERR(keypad->base);
+
+	keypad->regmap = devm_regmap_init_mmio(&pdev->dev,
+					       keypad->base,
+					       &keypad_regmap_cfg);
+	if (IS_ERR(keypad->regmap)) {
+		dev_err(&pdev->dev,
+			"regmap init failed:%ld\n", PTR_ERR(keypad->regmap));
+		return PTR_ERR(keypad->regmap);
+	}
+
+	bitmap_fill(keypad->keymap_state, MTK_KPD_NUM_BITS);
+
+	keypad->input_dev = devm_input_allocate_device(&pdev->dev);
+	if (!keypad->input_dev) {
+		dev_err(&pdev->dev, "Failed to allocate input dev\n");
+		return -ENOMEM;
+	}
+
+	keypad->input_dev->name = MTK_KPD_NAME;
+	keypad->input_dev->id.bustype = BUS_HOST;
+
+	ret = matrix_keypad_parse_properties(&pdev->dev, &keypad->n_rows,
+					     &keypad->n_cols);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to parse keypad params\n");
+		return ret;
+	}
+
+	if (device_property_read_u32(&pdev->dev, "mediatek,debounce-us",
+				     &debounce))
+		debounce = 16000;
+
+	if (debounce > MTK_KPD_DEBOUNCE_MAX_US) {
+		dev_err(&pdev->dev, "Debounce time exceeds the maximum allowed time %dus\n",
+			MTK_KPD_DEBOUNCE_MAX_US);
+		return -EINVAL;
+	}
+
+	wakeup = device_property_read_bool(&pdev->dev, "wakeup-source");
+
+	dev_dbg(&pdev->dev, "n_row=%d n_col=%d debounce=%d\n",
+		keypad->n_rows, keypad->n_cols, debounce);
+
+	ret = matrix_keypad_build_keymap(NULL, NULL,
+					 keypad->n_rows,
+					 keypad->n_cols,
+					 NULL,
+					 keypad->input_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to build keymap\n");
+		return ret;
+	}
+
+	regmap_write(keypad->regmap, MTK_KPD_DEBOUNCE,
+		     debounce * 32 / 1000 & MTK_KPD_DEBOUNCE_MASK);
+
+	keypad->clk = devm_clk_get(&pdev->dev, "kpd");
+	if (IS_ERR(keypad->clk))
+		return keypad->clk;
+
+	ret = clk_prepare_enable(keypad->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "cannot prepare/enable keypad clock\n");
+		return ret;
+	}
+
+	ret = devm_add_action_or_reset(&pdev->dev, kpd_clk_disable, keypad->clk);
+	if (ret)
+		return ret;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	ret = devm_request_threaded_irq(&pdev->dev, irq,
+					NULL, kpd_irq_handler, 0,
+					MTK_KPD_NAME, keypad);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to request IRQ#%d:%d\n",
+			irq, ret);
+		return ret;
+	}
+
+	ret = input_register_device(keypad->input_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to register device\n");
+		return ret;
+	}
+
+	return device_init_wakeup(&pdev->dev, wakeup);
+}
+
+static const struct of_device_id kpd_of_match[] = {
+	{ .compatible = "mediatek,mt6779-keypad" },
+	{ .compatible = "mediatek,mt6873-keypad" },
+	{ /* sentinel */ }
+};
+
+static struct platform_driver kpd_pdrv = {
+	.probe = kpd_pdrv_probe,
+	.driver = {
+		   .name = MTK_KPD_NAME,
+		   .of_match_table = kpd_of_match,
+	},
+};
+module_platform_driver(kpd_pdrv);
+
+MODULE_AUTHOR("Mediatek Corporation");
+MODULE_DESCRIPTION("MTK Keypad (KPD) Driver");
+MODULE_LICENSE("GPL");
-- 
2.18.0
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