[PATCH v20 0/3] Add matrix keypad driver support for Mediatek SoCs

[PATCH v20 0/3] Add matrix keypad driver support for Mediatek SoCs

[Mattijs Korpershoek]

Dear all,

This is a follow-up on an abandoned series, see [1]

Since Dmitry seemed generally happy with the driver, I applied his rename
recommendations.

Thus, I have made the following:

* All Reviewed-By: tags were kept
* Applied Marco's Reviewed-By: on the bindings (since he approved v10)
* Fengping is still the maintainer since he is the original author of this driver

Please tell me if you would rather have me do things differently.

[1] https://lore.kernel.org/all/20200909072159.14888-1-fengping.yu@mediatek.com/

v19 -> v20:
bindings: use dual license
bindings: fixed 2 indentation issues found by yamllint
bindings: drop clock-names description
bindings: use standard keyboard node name for example
bindings: use default: keyword for default values
use debounce-delay-ms property instead of mediatek,debounce-us

fengping.yu (3):
  dt-bindings: input: Add bindings for Mediatek matrix keypad
  Input: mt6779-keypad - Add MediaTek keypad driver
  arm64: defconfig: Add CONFIG_KEYBOARD_MT6779=m

 .../input/mediatek,mt6779-keypad.yaml         |  77 +++++++
 arch/arm64/configs/defconfig                  |   1 +
 drivers/input/keyboard/Kconfig                |  12 +
 drivers/input/keyboard/Makefile               |   1 +
 drivers/input/keyboard/mt6779-keypad.c        | 218 ++++++++++++++++++
 5 files changed, 309 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/mediatek,mt6779-keypad.yaml
 create mode 100644 drivers/input/keyboard/mt6779-keypad.c


base-commit: 87a0b2fafc09766d8c55461a18345a1cfb10a7fe
-- 
2.32.0

[PATCH v20 1/3] dt-bindings: input: Add bindings for Mediatek matrix keypad

[Mattijs Korpershoek]

From: "fengping.yu" <fengping.yu@mediatek.com>

This patch add devicetree bindings for Mediatek matrix keypad driver.

Signed-off-by: fengping.yu <fengping.yu@mediatek.com>
Reviewed-by: Marco Felsch <m.felsch@pengutronix.de>
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
---
 .../input/mediatek,mt6779-keypad.yaml         | 77 +++++++++++++++++++
 1 file changed, 77 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/mediatek,mt6779-keypad.yaml

diff --git a/Documentation/devicetree/bindings/input/mediatek,mt6779-keypad.yaml b/Documentation/devicetree/bindings/input/mediatek,mt6779-keypad.yaml
new file mode 100644
index 000000000000..b1770640f94b
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/mediatek,mt6779-keypad.yaml
@@ -0,0 +1,77 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/mediatek,mt6779-keypad.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Mediatek's Keypad Controller device tree bindings
+
+maintainers:
+  - Fengping Yu <fengping.yu@mediatek.com>
+
+allOf:
+  - $ref: "/schemas/input/matrix-keymap.yaml#"
+
+description: |
+  Mediatek's Keypad controller is used to interface a SoC with a matrix-type
+  keypad device. The keypad controller supports multiple row and column lines.
+  A key can be placed at each intersection of a unique row and a unique column.
+  The keypad controller can sense a key-press and key-release and report the
+  event using a interrupt to the cpu.
+
+properties:
+  compatible:
+    oneOf:
+      - const: mediatek,mt6779-keypad
+      - items:
+          - enum:
+              - mediatek,mt6873-keypad
+          - const: mediatek,mt6779-keypad
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    items:
+      - const: kpd
+
+  wakeup-source:
+    description: use any event on keypad as wakeup event
+    type: boolean
+
+  debounce-delay-ms:
+    maximum: 256
+    default: 16
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - clock-names
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/input/input.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    soc {
+        #address-cells = <2>;
+        #size-cells = <2>;
+
+        keyboard@10010000 {
+          compatible = "mediatek,mt6779-keypad";
+          reg = <0 0x10010000 0 0x1000>;
+          interrupts = <GIC_SPI 75 IRQ_TYPE_EDGE_FALLING>;
+          clocks = <&clk26m>;
+          clock-names = "kpd";
+        };
+    };
-- 
2.32.0

[PATCH v20 2/3] Input: mt6779-keypad - Add MediaTek keypad driver

[Mattijs Korpershoek]

From: "fengping.yu" <fengping.yu@mediatek.com>

This patch adds matrix keypad support for Mediatek SoCs.

Signed-off-by: fengping.yu <fengping.yu@mediatek.com>
Reviewed-by: Marco Felsch <m.felsch@pengutronix.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
---
 drivers/input/keyboard/Kconfig         |  12 ++
 drivers/input/keyboard/Makefile        |   1 +
 drivers/input/keyboard/mt6779-keypad.c | 218 +++++++++++++++++++++++++
 3 files changed, 231 insertions(+)
 create mode 100644 drivers/input/keyboard/mt6779-keypad.c

diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
index 0c607da9ee10..03a9530f620e 100644
--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@ -779,6 +779,18 @@ config KEYBOARD_BCM
 	  To compile this driver as a module, choose M here: the
 	  module will be called bcm-keypad.
 
+config KEYBOARD_MT6779
+	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 mt6779-keypad.
+
 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 e3c8648f834e..721936e90290 100644
--- a/drivers/input/keyboard/Makefile
+++ b/drivers/input/keyboard/Makefile
@@ -44,6 +44,7 @@ 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-$(CONFIG_KEYBOARD_MT6779)		+= mt6779-keypad.o
 obj-$(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/mt6779-keypad.c b/drivers/input/keyboard/mt6779-keypad.c
new file mode 100644
index 000000000000..369366f18fd2
--- /dev/null
+++ b/drivers/input/keyboard/mt6779-keypad.c
@@ -0,0 +1,218 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2022 MediaTek Inc.
+ * Author Fengping Yu <fengping.yu@mediatek.com>
+ */
+#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		"mt6779-keypad"
+#define MTK_KPD_MEM		0x0004
+#define MTK_KPD_DEBOUNCE	0x0018
+#define MTK_KPD_DEBOUNCE_MASK	GENMASK(13, 0)
+#define MTK_KPD_DEBOUNCE_MAX_MS	256
+#define MTK_KPD_NUM_MEMS	5
+#define MTK_KPD_NUM_BITS	136	/* 4*32+8 MEM5 only use 8 BITS */
+
+struct mt6779_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 mt6779_keypad_regmap_cfg = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = sizeof(u32),
+	.max_register = 36,
+};
+
+static irqreturn_t mt6779_keypad_irq_handler(int irq, void *dev_id)
+{
+	struct mt6779_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;
+	int row, col;
+	int row_shift = get_count_order(keypad->n_cols);
+
+	regmap_bulk_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) {
+	/* For 32bits register, only bits [15:0] use to indicate key status */
+		if (bit_nr % 32 >= 16)
+			continue;
+
+		/* 1: not pressed, 0: pressed */
+		pressed = !test_bit(bit_nr, new_state);
+		dev_dbg(&keypad->input_dev->dev, "%s",
+			pressed ? "pressed" : "released");
+
+		row = bit_nr / 32;
+		col = bit_nr % 32;
+
+		code = keycode[MATRIX_SCAN_CODE(row, col, 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);
+	}
+
+	bitmap_copy(keypad->keymap_state, new_state, MTK_KPD_NUM_BITS);
+
+	return IRQ_HANDLED;
+}
+
+static void mt6779_keypad_clk_disable(void *data)
+{
+	clk_disable_unprepare(data);
+}
+
+static int mt6779_keypad_pdrv_probe(struct platform_device *pdev)
+{
+	struct mt6779_keypad *keypad;
+	unsigned int irq;
+	u32 debounce;
+	bool wakeup;
+	int error;
+
+	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,
+					       &mt6779_keypad_regmap_cfg);
+	if (IS_ERR(keypad->regmap)) {
+		dev_err(&pdev->dev,
+			"regmap init failed:%pe\n", 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;
+
+	error = matrix_keypad_parse_properties(&pdev->dev, &keypad->n_rows,
+					       &keypad->n_cols);
+	if (error) {
+		dev_err(&pdev->dev, "Failed to parse keypad params\n");
+		return error;
+	}
+
+	if (device_property_read_u32(&pdev->dev, "debounce-delay-ms",
+				     &debounce))
+		debounce = 16;
+
+	if (debounce > MTK_KPD_DEBOUNCE_MAX_MS) {
+		dev_err(&pdev->dev, "Debounce time exceeds the maximum allowed time %dms\n",
+			MTK_KPD_DEBOUNCE_MAX_MS);
+		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);
+
+	error = matrix_keypad_build_keymap(NULL, NULL,
+					   keypad->n_rows,
+					   keypad->n_cols,
+					   NULL,
+					   keypad->input_dev);
+	if (error) {
+		dev_err(&pdev->dev, "Failed to build keymap\n");
+		return error;
+	}
+
+	regmap_write(keypad->regmap, MTK_KPD_DEBOUNCE,
+		     (debounce * 32) & MTK_KPD_DEBOUNCE_MASK);
+
+	keypad->clk = devm_clk_get(&pdev->dev, "kpd");
+	if (IS_ERR(keypad->clk))
+		return PTR_ERR(keypad->clk);
+
+	error = clk_prepare_enable(keypad->clk);
+	if (error) {
+		dev_err(&pdev->dev, "cannot prepare/enable keypad clock\n");
+		return error;
+	}
+
+	error = devm_add_action_or_reset(&pdev->dev, mt6779_keypad_clk_disable, keypad->clk);
+	if (error)
+		return error;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	error = devm_request_threaded_irq(&pdev->dev, irq,
+					  NULL, mt6779_keypad_irq_handler,
+					  IRQF_ONESHOT,
+					  MTK_KPD_NAME, keypad);
+	if (error) {
+		dev_err(&pdev->dev, "Failed to request IRQ#%d:%d\n",
+			irq, error);
+		return error;
+	}
+
+	error = input_register_device(keypad->input_dev);
+	if (error) {
+		dev_err(&pdev->dev, "Failed to register device\n");
+		return error;
+	}
+
+	error =  device_init_wakeup(&pdev->dev, wakeup);
+	if (error)
+		dev_warn(&pdev->dev, "device_init_wakeup fail\n");
+
+	return 0;
+}
+
+static const struct of_device_id mt6779_keypad_of_match[] = {
+	{ .compatible = "mediatek,mt6779-keypad" },
+	{ .compatible = "mediatek,mt6873-keypad" },
+	{ /* sentinel */ }
+};
+
+static struct platform_driver mt6779_keypad_pdrv = {
+	.probe = mt6779_keypad_pdrv_probe,
+	.driver = {
+		   .name = MTK_KPD_NAME,
+		   .of_match_table = mt6779_keypad_of_match,
+	},
+};
+module_platform_driver(mt6779_keypad_pdrv);
+
+MODULE_AUTHOR("Mediatek Corporation");
+MODULE_DESCRIPTION("MTK Keypad (KPD) Driver");
+MODULE_LICENSE("GPL");
-- 
2.32.0

[PATCH v20 3/3] arm64: defconfig: Add CONFIG_KEYBOARD_MT6779=m

[Mattijs Korpershoek]

From: "fengping.yu" <fengping.yu@mediatek.com>

Add Mediatek matrix keypad support in defconfig.

Signed-off-by: fengping.yu <fengping.yu@mediatek.com>
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Reviewed-by: Marco Felsch <m.felsch@pengutronix.de>
---
 arch/arm64/configs/defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
index f2e2b9bdd702..099a9e68711c 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig
@@ -390,6 +390,7 @@ CONFIG_KEYBOARD_GPIO=y
 CONFIG_KEYBOARD_SNVS_PWRKEY=m
 CONFIG_KEYBOARD_IMX_SC_KEY=m
 CONFIG_KEYBOARD_CROS_EC=y
+CONFIG_KEYBOARD_MT6779=m
 CONFIG_INPUT_TOUCHSCREEN=y
 CONFIG_TOUCHSCREEN_ATMEL_MXT=m
 CONFIG_TOUCHSCREEN_GOODIX=m
-- 
2.32.0

Re: [PATCH v20 2/3] Input: mt6779-keypad - Add MediaTek keypad driver

[Andy Shevchenko]

On Thu, Jan 27, 2022 at 12:15:25PM +0100, Mattijs Korpershoek wrote:
> From: "fengping.yu" <fengping.yu@mediatek.com>
> 
> This patch adds matrix keypad support for Mediatek SoCs.

Some comments which may be addressed now or in the follow-up patch(es).
Up to you.

...

> +static const struct regmap_config mt6779_keypad_regmap_cfg = {
> +	.reg_bits = 32,
> +	.val_bits = 32,

> +	.reg_stride = sizeof(u32),

I'm wondering if we need this when we have reg_bits = 32 already.

> +	.max_register = 36,
> +};

...

> +	regmap_write(keypad->regmap, MTK_KPD_DEBOUNCE,
> +		     (debounce * 32) & MTK_KPD_DEBOUNCE_MASK);

I'm wondering if << 5 is more specific to show that the value
is based on 2^5 units.

...

> +	error = devm_add_action_or_reset(&pdev->dev, mt6779_keypad_clk_disable, keypad->clk);

You have this long line...

> +	error = devm_request_threaded_irq(&pdev->dev, irq,
> +					  NULL, mt6779_keypad_irq_handler,
> +					  IRQF_ONESHOT,
> +					  MTK_KPD_NAME, keypad);

...at the same time you may reduce LOCs here...

> +	if (error) {
> +		dev_err(&pdev->dev, "Failed to request IRQ#%d:%d\n",
> +			irq, error);

...and here.

> +		return error;
> +	}

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v20 2/3] Input: mt6779-keypad - Add MediaTek keypad driver

[Mattijs Korpershoek]

On Thu, Jan 27, 2022 at 17:20, Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:

> On Thu, Jan 27, 2022 at 12:15:25PM +0100, Mattijs Korpershoek wrote:
>> From: "fengping.yu" <fengping.yu@mediatek.com>
>> 
>> This patch adds matrix keypad support for Mediatek SoCs.
>
> Some comments which may be addressed now or in the follow-up patch(es).
> Up to you.
Hi Andy,
Thank you for your review and your suggestions.

>
> ...
>
>> +static const struct regmap_config mt6779_keypad_regmap_cfg = {
>> +	.reg_bits = 32,
>> +	.val_bits = 32,
>
>> +	.reg_stride = sizeof(u32),
>
> I'm wondering if we need this when we have reg_bits = 32 already.

Per my understanding, .reg_stride is mainly used to check for invalid register
addresses in regmap_{read,write}():

    if (!IS_ALIGNED(reg, map->reg_stride))
            return -EINVAL;

If .reg_stride is not set, regmap core will default it to 1.
It's not computed from reg_bits.

So I think we still need it.
>
>> +	.max_register = 36,
>> +};
>
> ...
>
>> +	regmap_write(keypad->regmap, MTK_KPD_DEBOUNCE,
>> +		     (debounce * 32) & MTK_KPD_DEBOUNCE_MASK);
>
> I'm wondering if << 5 is more specific to show that the value
> is based on 2^5 units.

The datasheet I've seen states: "De-bounce time = KP_DEBOUNCE / 32ms"
But rewriting it as 1 << 5 seems reasonable as well:
regmap_write(keypad->regmap, MTK_KPD_DEBOUNCE,
            (debounce * (1 << 5)) & MTK_KPD_DEBOUNCE_MASK);

I don't have any preference on this one.
If I have to send a v21, I will rewrite it using (1 << 5)

>
> ...
>
>> +	error = devm_add_action_or_reset(&pdev->dev, mt6779_keypad_clk_disable, keypad->clk);
>
> You have this long line...
>
>> +	error = devm_request_threaded_irq(&pdev->dev, irq,
>> +					  NULL, mt6779_keypad_irq_handler,
>> +					  IRQF_ONESHOT,
>> +					  MTK_KPD_NAME, keypad);
>
> ...at the same time you may reduce LOCs here...
Ack. will join lines to reduce LOCs if I have to send v21.
>
>> +	if (error) {
>> +		dev_err(&pdev->dev, "Failed to request IRQ#%d:%d\n",
>> +			irq, error);
>
> ...and here.
Ack. will join lines to reduce LOCs if I have to send v21.

>
>> +		return error;
>> +	}
>
> -- 
> With Best Regards,
> Andy Shevchenko

Re: [PATCH v20 2/3] Input: mt6779-keypad - Add MediaTek keypad driver

[Andy Shevchenko]

On Fri, Jan 28, 2022 at 11:03:08AM +0100, Mattijs Korpershoek wrote:
> On Thu, Jan 27, 2022 at 17:20, Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:
> > On Thu, Jan 27, 2022 at 12:15:25PM +0100, Mattijs Korpershoek wrote:

...

> > Up to you.

> Thank you for your review and your suggestions.

Yes, as I said it you need a new version and consider them good.
Thanks!

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v20 1/3] dt-bindings: input: Add bindings for Mediatek matrix keypad

[Rob Herring]

On Thu, 27 Jan 2022 12:15:24 +0100, Mattijs Korpershoek wrote:
> From: "fengping.yu" <fengping.yu@mediatek.com>
> 
> This patch add devicetree bindings for Mediatek matrix keypad driver.
> 
> Signed-off-by: fengping.yu <fengping.yu@mediatek.com>
> Reviewed-by: Marco Felsch <m.felsch@pengutronix.de>
> Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
> ---
>  .../input/mediatek,mt6779-keypad.yaml         | 77 +++++++++++++++++++
>  1 file changed, 77 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/input/mediatek,mt6779-keypad.yaml
> 

Reviewed-by: Rob Herring <robh@kernel.org>