Re: [PATCH V3 2/2] drivers: input: keyboard: add mtk keypad driver

Signed-off-by: fengping.yu <redacted>

Add matrix keypad driver for MTK SoC.

---
 arch/arm64/configs/defconfig     |   1 +
 drivers/input/keyboard/Kconfig   |   8 +
 drivers/input/keyboard/Makefile  |   1 +
 drivers/input/keyboard/mtk-kpd.c | 280 +++++++++++++++++++++++++++++++
 4 files changed, 290 insertions(+)
 create mode 100644 drivers/input/keyboard/mtk-kpd.c

diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
index 8e05c39eab08..62bed77ec127 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig

@@ -315,6 +315,7 @@ CONFIG_KEYBOARD_ADC=m
 CONFIG_KEYBOARD_GPIO=y
 CONFIG_KEYBOARD_SNVS_PWRKEY=m
 CONFIG_KEYBOARD_CROS_EC=y
+CONFIG_KEYBOARD_MTK=y
 CONFIG_INPUT_TOUCHSCREEN=y
 CONFIG_TOUCHSCREEN_ATMEL_MXT=m
 CONFIG_INPUT_MISC=y

diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
index 8911bc2ec42a..01747a97536b 100644
--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig

@@ -775,4 +775,12 @@ config KEYBOARD_MTK_PMIC
 	  To compile this driver as a module, choose M here: the
 	  module will be called pmic-keys.
 
+config KEYBOARD_MTK
+	tristate "MediaTek Keypad Support"
+	help
+	  Say Y here if you want to use the keypad.
+	  If unuse, say N.
+	  To compile this driver as a module, choose M here: the
+	  module will be called mtk-kpd.
+
 endif

diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
index 9510325c0c5d..daa654bcce6e 100644
--- a/drivers/input/keyboard/Makefile
+++ b/drivers/input/keyboard/Makefile

@@ -41,6 +41,7 @@ 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-$(CONFIG_KEYBOARD_MTK) 		+= mtk-kpd.o
 obj-$(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..e36461c9dd89
--- /dev/null
+++ b/drivers/input/keyboard/mtk-kpd.c

@@ -0,0 +1,280 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 MediaTek Inc.
+ * Author Terry Chang <terry.chang@mediatek.com>
+ */
+#include <linux/clk.h>
+#include <linux/fs.h>
+#include <linux/gpio.h>
+#include <linux/init.h>
+#include <linux/input/matrix_keypad.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#define KPD_NAME	"mtk-kpd"
+
+#define KP_STA				0x0000
+#define KP_MEM1				0x0004
+#define KP_MEM2				0x0008
+#define KP_MEM3				0x000c
+#define KP_MEM4				0x0010
+#define KP_MEM5				0x0014
+#define KP_DEBOUNCE			0x0018
+#define KP_SEL				0x0020
+#define KP_EN				0x0024
+
+#define KP_COL0_SEL		BIT(10)
+#define KP_COL1_SEL		BIT(11)
+#define KP_COL2_SEL		BIT(12)
+
+#define KPD_DEBOUNCE_MASK	GENMASK_ULL(13, 0)
+
+#define KPD_NUM_MEMS	5
+#define KPD_MEM5_BITS	8
+#define KPD_NUM_KEYS	72	/* 4 * 16 + KPD_MEM5_BITS */
+
+struct mtk_keypad {
+	struct input_dev *input_dev;
+	struct clk *clk;
+	void __iomem *base;
+	unsigned int irqnr;
+	bool wakeup;
+	u32 key_debounce;
+	u32 n_rows;
+	u32 n_cols;
+	u32 keymap_state[KPD_NUM_MEMS];

+};
+
+static void kpd_get_keymap_state(void __iomem *kp_base, u32 state[])
+{
+	memset_io(state, 0xff, KPD_NUM_MEMS);
+	memcpy_fromio(state, kp_base, KPD_NUM_MEMS);
+}
+
+static irqreturn_t kpd_irq_handler(int irq, void *dev_id)
+{
+	/* use _nosync to avoid deadlock */
+	struct mtk_keypad *keypad = dev_id;
+	unsigned short *keycode = keypad->input_dev->keycode;
+	u32 new_state[KPD_NUM_MEMS], mask;

+	unsigned long change = 0;
+	int bit_nr;
+	int pressed;
+	u32 row_shift = get_count_order(keypad->n_cols);
+	unsigned short code;
+	int i;
+
+	disable_irq_nosync(keypad->irqnr);

+
+	for (i = 0; i < KPD_NUM_MEMS; i++) {
+		change = new_state[i] ^ keypad->keymap_state[i];
+		if (!change)
+			continue;
+
+		for_each_set_bit(bit_nr, &change, 32) {
+			mask = 1 << bit_nr;
+			pressed = (new_state[i] & mask) == 0U;
+			dev_dbg(&keypad->input_dev->dev,
+				"%s", pressed ? "pressed" : "released");
+
+			code = keycode[MATRIX_SCAN_CODE(i, bit_nr, row_shift)];
+
+			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);
+		}
+	}
+
+	memcpy(keypad->keymap_state, new_state, sizeof(new_state));

+
+	return IRQ_HANDLED;
+}
+
+static int kpd_get_dts_info(struct mtk_keypad *keypad)
+{
+	int ret;
+	struct device *dev = keypad->input_dev->dev.parent;
+	struct device_node *node = dev->of_node;
+
+	ret = matrix_keypad_parse_properties(dev, &keypad->n_rows,
+					     &keypad->n_cols);
+
+	if (ret) {
+		dev_err(dev, "failed to parse keypad params.\n");
+		return ret;
+	}
+
+	ret = of_property_read_u32(node, "mediatek,debounce-us",
+				   &keypad->key_debounce);