Re: [PATCH v5 09/11] input: keyboard: Add support for MAX7360 keypad

[Andy Shevchenko]

On Tue, Mar 18, 2025 at 05:26:25PM +0100, Mathieu Dubois-Briand wrote:
> Add driver for Maxim Integrated MAX7360 keypad controller, providing
> support for up to 64 keys, with a matrix of 8 columns and 8 rows.

...

> +	help
> +	  If you say yes here you get support for the keypad controller on the
> +	  Maxim MAX7360 I/O Expander.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called max7360_keypad.

One paragraph is wrapped way too late or too early, can you make them approx.
the same in terms of a line width?

...

+ bitfield.h
+ bitops.h
+ dev_printk.h
+ device/devres.h
+ err.h

> +#include <linux/init.h>
> +#include <linux/input.h>
> +#include <linux/input/matrix_keypad.h>
> +#include <linux/interrupt.h>
> +#include <linux/mfd/max7360.h>

+ mod_devicetable.h

> +#include <linux/module.h>
> +#include <linux/property.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_wakeirq.h>
> +#include <linux/regmap.h>

> +#include <linux/slab.h>

IS it used? I think it's device/devres.h that covers it.


...

> +static int max7360_keypad_open(struct input_dev *pdev)
> +{
> +	struct max7360_keypad *max7360_keypad = input_get_drvdata(pdev);
> +	int ret;
> +
> +	/*
> +	 * Somebody is using the device: get out of sleep.
> +	 */
> +	ret = regmap_write_bits(max7360_keypad->regmap, MAX7360_REG_CONFIG,
> +				MAX7360_CFG_SLEEP, MAX7360_CFG_SLEEP);
> +	if (ret) {
> +		dev_err(&max7360_keypad->input->dev,
> +			"Failed to write max7360 configuration\n");

> +		return ret;
> +	}
> +
> +	return 0;

Just

	return ret;

?

> +}

...

> +	/*
> +	 * Nobody is using the device anymore: go to sleep.
> +	 */

The comment message can take only a line.

> +	ret = regmap_write_bits(max7360_keypad->regmap, MAX7360_REG_CONFIG, MAX7360_CFG_SLEEP, 0);
> +	if (ret)
> +		dev_err(&max7360_keypad->input->dev,
> +			"Failed to write max7360 configuration\n");
> +}

...

> +static int max7360_keypad_parse_dt(struct platform_device *pdev,

s/dt/fw

> +				   struct max7360_keypad *max7360_keypad,
> +				   bool *autorepeat)
> +{

	struct device *dev = &pdev>dev;

but why not supply struct device to begin with? How is the platform part used here?

> +	int ret;
> +
> +	ret = matrix_keypad_parse_properties(pdev->dev.parent, &max7360_keypad->rows,
> +					     &max7360_keypad->cols);
> +	if (ret)
> +		return ret;
> +
> +	if (!max7360_keypad->rows || !max7360_keypad->cols ||
> +	    max7360_keypad->rows > MAX7360_MAX_KEY_ROWS ||
> +	    max7360_keypad->cols > MAX7360_MAX_KEY_COLS) {

See also below comment.

> +		dev_err(&pdev->dev,
> +			"Invalid number of columns or rows (%ux%u)\n",
> +			max7360_keypad->cols, max7360_keypad->rows);
> +		return -EINVAL;
> +	}
> +
> +	*autorepeat = device_property_read_bool(pdev->dev.parent, "autorepeat");
> +
> +	max7360_keypad->debounce_ms = MAX7360_DEBOUNCE_MIN;
> +	ret = device_property_read_u32(pdev->dev.parent, "keypad-debounce-delay-ms",
> +				       &max7360_keypad->debounce_ms);
> +	if (ret == -EINVAL) {
> +		dev_info(&pdev->dev, "Using default keypad-debounce-delay-ms: %u\n",
> +			 max7360_keypad->debounce_ms);
> +	} else if (ret < 0) {
> +		dev_err(&pdev->dev,
> +			"Failed to read keypad-debounce-delay-ms property\n");
> +		return ret;

> +	} else if (max7360_keypad->debounce_ms < MAX7360_DEBOUNCE_MIN ||

Redundant 'else'.

> +		   max7360_keypad->debounce_ms > MAX7360_DEBOUNCE_MAX) {

Maybe in_range()? But up to you, it takes start:len and not start:end.

> +		dev_err(&pdev->dev,
> +			"Invalid keypad-debounce-delay-ms: %u, should be between %u and %u.\n",
> +			max7360_keypad->debounce_ms, MAX7360_DEBOUNCE_MIN, MAX7360_DEBOUNCE_MAX);
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}

...

> +static int max7360_keypad_probe(struct platform_device *pdev)
> +{
> +	struct max7360_keypad *max7360_keypad;

	struct device *dev = &pdev>dev;

> +	struct input_dev *input;
> +	bool autorepeat;
> +	int ret;
> +	int irq;

> +	if (!pdev->dev.parent)
> +		return dev_err_probe(&pdev->dev, -ENODEV, "No parent device\n");

Just do like in the rest, i.e. local variable for regmap and its validness will
be the one that indicates the wrong enumeration path.

> +	irq = platform_get_irq_byname(to_platform_device(pdev->dev.parent), "intk");
> +	if (irq < 0)
> +		return irq;
> +
> +	max7360_keypad = devm_kzalloc(&pdev->dev, sizeof(*max7360_keypad), GFP_KERNEL);
> +	if (!max7360_keypad)
> +		return -ENOMEM;
> +
> +	max7360_keypad->regmap = dev_get_regmap(pdev->dev.parent, NULL);
> +	if (!max7360_keypad->regmap)
> +		return dev_err_probe(&pdev->dev, -ENODEV, "Could not get parent regmap\n");
> +
> +	ret = max7360_keypad_parse_dt(pdev, max7360_keypad, &autorepeat);
> +	if (ret)
> +		return ret;
> +
> +	input = devm_input_allocate_device(pdev->dev.parent);
> +	if (!input)
> +		return -ENOMEM;
> +
> +	max7360_keypad->input = input;
> +
> +	input->id.bustype = BUS_I2C;
> +	input->name = pdev->name;
> +	input->open = max7360_keypad_open;
> +	input->close = max7360_keypad_close;
> +
> +	ret = matrix_keypad_build_keymap(NULL, NULL, MAX7360_MAX_KEY_ROWS, MAX7360_MAX_KEY_COLS,
> +					 max7360_keypad->keycodes, input);
> +	if (ret)

> +		return dev_err_probe(&pdev->dev, ret,
> +				     "Failed to build keymap\n");

One line.

> +
> +	input_set_capability(input, EV_MSC, MSC_SCAN);
> +	if (autorepeat)
> +		__set_bit(EV_REP, input->evbit);
> +
> +	input_set_drvdata(input, max7360_keypad);
> +
> +	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, max7360_keypad_irq,
> +					IRQF_TRIGGER_LOW | IRQF_ONESHOT,

What's wrong with the interrupt flags provided by firmware description?

> +					"max7360-keypad", max7360_keypad);
> +	if (ret)
> +		return dev_err_probe(&pdev->dev, ret, "Failed to register interrupt\n");
> +
> +	ret = input_register_device(input);
> +	if (ret)
> +		return dev_err_probe(&pdev->dev, ret, "Could not register input device\n");

> +	platform_set_drvdata(pdev, max7360_keypad);

Is it used?

> +	ret = max7360_keypad_hw_init(max7360_keypad);
> +	if (ret)
> +		return dev_err_probe(&pdev->dev, ret, "Failed to initialize max7360 keypad\n");
> +
> +	device_init_wakeup(&pdev->dev, true);
> +	ret = dev_pm_set_wake_irq(&pdev->dev, irq);
> +	if (ret)
> +		dev_warn(&pdev->dev, "Failed to set up wakeup irq: %d\n", ret);
> +
> +	return 0;
> +}

-- 
With Best Regards,
Andy Shevchenko