[PATCH v5] add mtk matrix keypad driver for keypad on MTK SoC

[PATCH v5] add mtk matrix keypad driver for keypad on MTK SoC

[Fengping yu]

Change since v4:
- remove extra space and redundant lines
- remove disable_irq_nosync and enable_irq in irq handler
- put defconfig as a single patch
- unified device properties interface for ACPI and device trees
- fixed other issue according reviewer comments

fengping.yu (3):
  dt-bindings: add matrix keypad documentation
  arm64: configs: defconfig: enable mtk keypad config
  drivers: input: keyboard: add mtk keypad driver

 .../devicetree/bindings/input/mtk-kpd.txt     |  61 +++++
 arch/arm64/configs/defconfig                  |   1 +
 drivers/input/keyboard/Kconfig                |   9 +
 drivers/input/keyboard/Makefile               |   1 +
 drivers/input/keyboard/mtk-kpd.c              | 242 ++++++++++++++++++
 5 files changed, 314 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/mtk-kpd.txt
 create mode 100644 drivers/input/keyboard/mtk-kpd.c

--
2.18.0

Re: [PATCH v5 1/3] dt-bindings: add matrix keypad documentation

[Marco Felsch]

Hi Fengping,

On 20-04-23 09:19, Fengping yu wrote:
> From: "fengping.yu" <fengping.yu@mediatek.com>
> 
> Signed-off-by: fengping.yu <fengping.yu@mediatek.com>
> ---
>  .../devicetree/bindings/input/mtk-kpd.txt     | 61 +++++++++++++++++++

Pls don't add new binding docs as .txt instead you should use the new
yaml schema.

Regards,
  Marco

>  1 file changed, 61 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/input/mtk-kpd.txt
> 
> diff --git a/Documentation/devicetree/bindings/input/mtk-kpd.txt b/Documentation/devicetree/bindings/input/mtk-kpd.txt
> new file mode 100644
> index 000000000000..8b154a5e2f7d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/mtk-kpd.txt
> @@ -0,0 +1,61 @@
> +* Mediatek's Keypad Controller device tree binding
> +
> +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.
> +
> +Required properties:
> +- compatible should contain:
> +	* "mediatek,kp" for common keypad
> +	* "mediatek,mt6779-keypad" for specific keypad chip
> +
> +- reg: The base address of the Keypad register bank.
> +
> +- interrupts: A single interrupt specifier.
> +
> +- mediatek,debounce-us: Debounce interval in microseconds, maximum value
> +  is 256000 microseconds.
> +
> +- keypad,num-rows: Number of row lines connected to the keypad controller, it is
> +	not equal to PCB rows number, instead you should add required value for each IC.
> +
> +- keypad,num-columns: Number of column lines connected to the keypad controller,
> +	it is not equal to PCB columns number, instead you should add required value
> +	for each IC.
> +
> +- linux,keymap: The keymap for keys as described in the binding document
> +  devicetree/bindings/input/matrix-keymap.txt.
> +
> +- pinctrl: Should specify pin control groups used for this controller.
> +  See ../pinctrl/pinctrl-bindings.txt for details.
> +
> +- clocks: Must contain one entry, for the module clock.
> +  See ../clocks/clock-bindings.txt for details.
> +
> +- clock-names: Names of the clocks listed in clocks property in the same order.
> +
> +Optional Properties:
> +- wakeup-source: use any event on keypad as wakeup event.
> +
> +Example:
> +
> +	keypad: kp@10010000 {
> +		compatible = "mediatek,kp";
> +		reg = <0 0x10010000 0 0x1000>;
> +		wakeup-source;
> +		interrupts = <GIC_SPI 75 IRQ_TYPE_EDGE_FALLING>;
> +		clocks = <&clk26m>;
> +		clock-names = "kpd";
> +	};
> +
> +	&keypad {
> +		mediatek,debounce-us = <32000>;
> +		keypad,num-rows = <8>;
> +		keypad,num-columns = <9>;
> +		linux,keymap = < MATRIX_KEY(0x00, 0x00, KEY_VOLUMEDOWN) >;
> +		status = "okay";
> +		pinctrl-names = "default";
> +		pinctrl-0 = <&kpd_gpios_def_cfg>;
> +	};
> -- 
> 2.18.0

-- 
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Re: [PATCH v5 2/3] arm64: configs: defconfig: enable mtk keypad config

[Marco Felsch]

On 20-04-23 09:20, Fengping yu wrote:
> From: "fengping.yu" <fengping.yu@mediatek.com>
> 
> Signed-off-by: fengping.yu <fengping.yu@mediatek.com>

Nit, this should be the last patch in this series. Also you need to add
a few comments wihtin the commit message. Empty commit messages are not
allowed.

Regards,
  Marco

> ---
>  arch/arm64/configs/defconfig | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
> index 0f212889c931..7863352521e5 100644
> --- a/arch/arm64/configs/defconfig
> +++ b/arch/arm64/configs/defconfig
> @@ -316,6 +316,7 @@ CONFIG_KEYBOARD_GPIO=y
>  CONFIG_KEYBOARD_SNVS_PWRKEY=m
>  CONFIG_KEYBOARD_IMX_SC_KEY=m
>  CONFIG_KEYBOARD_CROS_EC=y
> +CONFIG_KEYBOARD_MTK_KPD=y
>  CONFIG_INPUT_TOUCHSCREEN=y
>  CONFIG_TOUCHSCREEN_ATMEL_MXT=m
>  CONFIG_INPUT_MISC=y
> -- 
> 2.18.0

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

Re: [PATCH v5] add mtk matrix keypad driver for keypad on MTK SoC

[Marco Felsch]

Hi Fengping,

On 20-04-23 09:19, Fengping yu wrote:
> 
> Change since v4:
> - remove extra space and redundant lines
> - remove disable_irq_nosync and enable_irq in irq handler
> - put defconfig as a single patch
> - unified device properties interface for ACPI and device trees

This is a good changelog for reviewers.

> - fixed other issue according reviewer comments

This one is a bit useless..

Regards,
  Marco

> fengping.yu (3):
>   dt-bindings: add matrix keypad documentation
>   arm64: configs: defconfig: enable mtk keypad config
>   drivers: input: keyboard: add mtk keypad driver
> 
>  .../devicetree/bindings/input/mtk-kpd.txt     |  61 +++++
>  arch/arm64/configs/defconfig                  |   1 +
>  drivers/input/keyboard/Kconfig                |   9 +
>  drivers/input/keyboard/Makefile               |   1 +
>  drivers/input/keyboard/mtk-kpd.c              | 242 ++++++++++++++++++
>  5 files changed, 314 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/input/mtk-kpd.txt
>  create mode 100644 drivers/input/keyboard/mtk-kpd.c
> 
> --
> 2.18.0
> 

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

Re: [PATCH v5 3/3] drivers: input: keyboard: add mtk keypad driver

[Marco Felsch]

Hi Fengping,

On 20-04-23 09:20, Fengping yu wrote:
> From: "fengping.yu" <fengping.yu@mediatek.com>

Missing commit message?

> Signed-off-by: fengping.yu <fengping.yu@mediatek.com>
> ---
>  drivers/input/keyboard/Kconfig   |   9 ++
>  drivers/input/keyboard/Makefile  |   1 +
>  drivers/input/keyboard/mtk-kpd.c | 242 +++++++++++++++++++++++++++++++
>  3 files changed, 252 insertions(+)
>  create mode 100644 drivers/input/keyboard/mtk-kpd.c
> 
> diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
> index 4706ff09f0e8..4a387d8683b1 100644
> --- a/drivers/input/keyboard/Kconfig
> +++ b/drivers/input/keyboard/Kconfig
> @@ -772,6 +772,15 @@ 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"

I think here are some missing deps.

> +	help
> +	  Say Y here if you want to use the keypad.

I would write:
"Say Y here if you want to use the keypad on MediaTek SoCs"

> +	  If unuse, say N.

s/unuse/unsure/

> +
> +	  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 f5b17524adf2..63324d3e36c5 100644
> --- a/drivers/input/keyboard/Makefile
> +++ b/drivers/input/keyboard/Makefile
> @@ -42,6 +42,7 @@ 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..7f8f091b2734
> --- /dev/null
> +++ b/drivers/input/keyboard/mtk-kpd.c
> @@ -0,0 +1,242 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2019 MediaTek Inc.
> + * Author Terry Chang <terry.chang@mediatek.com>
> + */
> +#include <linux/clk.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>

Pls, check if all includes are needed.

> +
> +#define KPD_NAME	"mtk-kpd"
> +
> +#define KP_MEM		0x0004
> +#define KP_DEBOUNCE	0x0018
> +
> +#define KPD_DEBOUNCE_MASK	GENMASK(13, 0)
> +#define KPD_DEBOUNCE_MAX	256000
> +#define KPD_NUM_MEMS	5
> +#define KPD_NUM_BITS	136	/* 4 * 32 + 8 MEM5 only use 8 BITS */
> +#define BITS_TO_U32(nr)	DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(u32))
> +
> +struct mtk_keypad {
> +	struct input_dev *input_dev;
> +	struct clk *clk;
> +	void __iomem *base;
> +	unsigned int irqnr;

You don't need the irqnr here.

> +	bool wakeup;
> +	u32 key_debounce;
> +	u32 n_rows;
> +	u32 n_cols;
> +	DECLARE_BITMAP(keymap_state, KPD_NUM_BITS);
> +};
> +
> +static irqreturn_t kpd_irq_handler(int irq, void *dev_id)
> +{
> +	/* use _nosync to avoid deadlock */

What did you mean by this comment?

> +	struct mtk_keypad *keypad = dev_id;
> +	unsigned short *keycode = keypad->input_dev->keycode;
> +	DECLARE_BITMAP(new_state, KPD_NUM_BITS);
> +	DECLARE_BITMAP(change, KPD_NUM_BITS);
> +	int bit_nr;
> +	int pressed;
> +	unsigned short code;
> +
> +	memcpy_fromio(new_state, keypad->base + KP_MEM, KPD_NUM_MEMS);

As I written below, pls make use of the regmap() framework.

> +	bitmap_xor(change, new_state, keypad->keymap_state, KPD_NUM_BITS);
> +
> +	for_each_set_bit(bit_nr, change, KPD_NUM_BITS) {
> +		pressed = test_bit(bit_nr, new_state) == 0U;

I would write !test_bit() and add a comment /* pressed == 0 */

> +		dev_dbg(&keypad->input_dev->dev, "%s",
> +			pressed ? "pressed" : "released");
> +
> +	/* per 32bit register only use low 16bit as keypad mem register */

Pls, align the comment.

> +		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, KPD_NUM_BITS);
> +
> +	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);
> +

Unnecessary newline.

> +	if (ret) {
> +		dev_err(dev, "Failed to parse keypad params\n");
> +		return ret;
> +	}
> +
> +	ret = device_property_read_u32(dev, "mediatek,debounce-us",
> +				   &keypad->key_debounce);
> +	if (ret) {
> +		dev_err(dev, "Failed to read mediatek debounce time\n");
> +		return ret;
> +	}
> +
> +	if (keypad->key_debounce > KPD_DEBOUNCE_MAX) {
> +		dev_err(dev, "Debounce time exceeds the maximum allowed time 256ms\n");
> +		return -EINVAL;
> +	}
> +
> +	keypad->wakeup = device_property_read_bool(node, "wakeup-source");

Did you test this? It should be:

device_property_read_bool(dev, "wakeup-source");

> +
> +	dev_dbg(dev, "n_row=%d n_col=%d debounce=%d\n",
> +		keypad->n_rows, keypad->n_cols,
> +		keypad->key_debounce);
> +
> +	return 0;
> +}
> +
> +static int kpd_pdrv_probe(struct platform_device *pdev)
> +{
> +	struct mtk_keypad *keypad;
> +	struct pinctrl *keypad_pinctrl;
> +	struct pinctrl_state *kpd_default;
> +	int ret;
> +
> +	keypad = devm_kzalloc(&pdev->dev, sizeof(*keypad), GFP_KERNEL);
> +	if (!keypad)
> +		return -ENOMEM;
> +
> +	bitmap_fill(keypad->keymap_state, 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 = KPD_NAME;
> +	keypad->input_dev->id.bustype = BUS_HOST;
> +
> +	ret = kpd_get_dts_info(keypad);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Failed to get dts info\n");
> +		return ret;
> +	}
> +
> +	ret = matrix_keypad_build_keymap(NULL, NULL,
> +					keypad->n_rows,
> +					keypad->n_cols,
> +					NULL,
> +					keypad->input_dev);
> +

Unnecessary Newline.

> +	if (ret) {
> +		dev_err(&pdev->dev, "Failed to build keymap\n");
> +		return ret;
> +	}
> +
> +	input_set_drvdata(keypad->input_dev, keypad);
> +
> +	keypad->base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(keypad->base)) {
> +		dev_err(&pdev->dev, "Failed to get resource and iomap keypad\n");
> +		return PTR_ERR(keypad->base);
> +	}
> +
> +	if (keypad->key_debounce > KPD_DEBOUNCE_MAX) {
> +		dev_err(&pdev->dev, "Invalid debounce time value.\n");
> +		return -EINVAL;
> +	}

This check is already done withn the kpd_get_dts_info(). I would say to
drop the kpd_get_dts_info() function and probe it all within the probe()
function. It is not that much data you need and it removes the wakupsrc
var fromt the driver state. Furthermore devm_platform_ioremap_resource()
and devm_clk_get() parses the DT too. I would parse the deps before you
setup and fill the input_dev to fail early.

> +	writew(keypad->key_debounce * 32 / 1000 & KPD_DEBOUNCE_MASK,
> +		keypad->base + KP_DEBOUNCE);

Also I would avoid this completely and instead use the
regmap() interface which has mmio support.

> +	keypad->clk = devm_clk_get(&pdev->dev, "kpd");
> +	if (IS_ERR(keypad->clk)) {
> +		return PTR_ERR(keypad->clk);
> +	}
> +
> +	ret = clk_prepare_enable(keypad->clk);
> +	if (ret) {
> +		dev_err(&pdev->dev, "cannot prepare/enable keypad clock\n");
> +		return ret;
> +	}

Nit you can add a devm_add_action_or_reset() here to avoid the goto:
error handling.

> +	keypad_pinctrl = devm_pinctrl_get(&pdev->dev);
> +	if (IS_ERR(keypad_pinctrl)) {
> +		ret = PTR_ERR(keypad_pinctrl);
> +		goto disable_kpd_clk;
> +	}
> +
> +	kpd_default = pinctrl_lookup_state(keypad_pinctrl, "default");
> +	if (IS_ERR(kpd_default)) {
> +		dev_err(&pdev->dev, "No default pinctrl state\n");
> +		ret = PTR_ERR(kpd_default);
> +		goto disable_kpd_clk;
> +	}
> +
> +	pinctrl_select_state(keypad_pinctrl, kpd_default);
> +
> +	keypad->irqnr = platform_get_irq(pdev, 0);

As writting above, the irqnr can be a local var.

> +	if (keypad->irqnr < 0) {
> +		dev_err(&pdev->dev, "Failed to get irq\n");
> +		ret = -keypad->irqnr;
> +		goto disable_kpd_clk;
> +	}
> +
> +	ret = devm_request_irq(&pdev->dev, keypad->irqnr,
> +				kpd_irq_handler, 0,
> +				KPD_NAME, keypad);

Why do you don't use the threaded irq [devm_request_threaded_irq()]?

> +	if (ret) {
> +		dev_err(&pdev->dev, "Failed to request IRQ#%d:%d\n",
> +						keypad->irqnr, ret);
> +		goto disable_kpd_clk;
> +	}
> +
> +	ret = input_register_device(keypad->input_dev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Failed to register device\n");
> +		goto disable_kpd_clk;
> +	}
> +
> +	device_init_wakeup(&pdev->dev, keypad->wakeup);
> +
> +	platform_set_drvdata(pdev, keypad);

Where do you need the drvdata? It seems useless.

> +	return 0;
> +
> +disable_kpd_clk:
> +	clk_disable_unprepare(keypad->clk);
> +	return ret;
> +}
> +
> +static const struct of_device_id kpd_of_match[] = {
> +	{.compatible = "mediatek,kp"},
> +	{}

Nit { }

or

{ /*sentinel*/ }

> +};

MODULE_DEVICE_TABLE(of, kpd_of_match);

> +
> +static struct platform_driver kpd_pdrv = {
> +	.probe = kpd_pdrv_probe,
> +	.driver = {
> +		   .name = KPD_NAME,
> +		   .of_match_table = kpd_of_match,
> +	},
> +};
> +

Unnecessary newline.

Regards,
  Marco

> +module_platform_driver(kpd_pdrv);
> +
> +MODULE_AUTHOR("Mediatek Corporation");
> +MODULE_DESCRIPTION("MTK Keypad (KPD) Driver");
> +MODULE_LICENSE("GPL");

Re: [PATCH v5 3/3] drivers: input: keyboard: add mtk keypad driver

[Andy Shevchenko]

On Thu, Apr 23, 2020 at 09:20:02AM +0800, Fengping yu wrote:
> From: "fengping.yu" <fengping.yu@mediatek.com>
> 

This misses the commit message. It's a show stopper for such patches.
Read this [1].

[1]: https://chris.beams.io/posts/git-commit/

...

> +#define KPD_DEBOUNCE_MASK	GENMASK(13, 0)
> +#define KPD_DEBOUNCE_MAX	256000

Is there any unit in which debounce time is being measured? Add it as a suffix
to the definition, if it's possible.

...

> +#define BITS_TO_U32(nr)	DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(u32))

This already defined in bits.h.

...

> +	keypad->base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(keypad->base)) {

> +		dev_err(&pdev->dev, "Failed to get resource and iomap keypad\n");

This is duplicate noisy message, please remove.

> +		return PTR_ERR(keypad->base);
> +	}

...

> +	writew(keypad->key_debounce * 32 / 1000 & KPD_DEBOUNCE_MASK,

Perhaps one pair of parentheses is needed to make logic clear.

(Yes, I remember I commented on this in earlier versions where it was many
 parentheses around above calculations, but you have to use common sense as well)

> +		keypad->base + KP_DEBOUNCE);

-- 
With Best Regards,
Andy Shevchenko