Re: [PATCH v7 10/11] input: misc: Add support for MAX7360 rotary

[Andy Shevchenko <andriy.shevchenko@intel.com>]

On Mon, Apr 28, 2025 at 01:57:28PM +0200, Mathieu Dubois-Briand wrote:
> Add driver for Maxim Integrated MAX7360 rotary encoder controller,
> supporting a single rotary switch.

...

> +struct max7360_rotary {
> +	struct input_dev *input;
> +	unsigned int debounce_ms;
> +	struct regmap *regmap;
> +
> +	u32 steps;
> +	u32 axis;
> +	bool relative_axis;
> +	bool rollover;
> +
> +	unsigned int pos;
> +};

I believe `pahole` can recommend better layout (look for the better position
of debounce_ms).

...

> +static void max7360_rotaty_report_event(struct max7360_rotary *max7360_rotary, int steps)
> +{
> +	if (max7360_rotary->relative_axis) {
> +		input_report_rel(max7360_rotary->input, max7360_rotary->axis, steps);
> +	} else {
> +		unsigned int pos = max7360_rotary->pos;
> +
> +		if (steps < 0) {
> +			/* turning counter-clockwise */
> +			if (max7360_rotary->rollover)
> +				pos += max7360_rotary->steps + steps;
> +			else

> +				pos = max(0, (int)pos + steps);

Please, no castings for min()/max()/clamp(). It diminishes the use of those
macros.

> +		} else {
> +			/* turning clockwise */
> +			if (max7360_rotary->rollover)
> +				pos += steps;
> +			else
> +				pos = min(max7360_rotary->steps, pos + steps);
> +		}
> +
> +		if (max7360_rotary->rollover)
> +			pos %= max7360_rotary->steps;
> +
> +		max7360_rotary->pos = pos;
> +		input_report_abs(max7360_rotary->input, max7360_rotary->axis, max7360_rotary->pos);
> +	}
> +
> +	input_sync(max7360_rotary->input);
> +}

...

> +static irqreturn_t max7360_rotary_irq(int irq, void *data)
> +{
> +	struct max7360_rotary *max7360_rotary = data;
> +	struct device *dev = max7360_rotary->input->dev.parent;
> +	unsigned int val;
> +	int error;
> +
> +	error = regmap_read(max7360_rotary->regmap, MAX7360_REG_RTR_CNT, &val);
> +	if (error < 0) {
> +		dev_err(dev, "Failed to read rotary counter\n");
> +		return IRQ_NONE;
> +	}
> +
> +	if (val == 0) {

> +		dev_dbg(dev, "Got a spurious interrupt\n");

This contradicts with the IRQF_SHARED. Drop one of them.

> +		return IRQ_NONE;
> +	}
> +
> +	max7360_rotaty_report_event(max7360_rotary, sign_extend32(val, 7));
> +
> +	return IRQ_HANDLED;
> +}

...

> +static int max7360_rotary_hw_init(struct max7360_rotary *max7360_rotary)
> +{
> +	struct device *dev = max7360_rotary->input->dev.parent;
> +	int val;
> +	int error;
> +
> +	val = FIELD_PREP(MAX7360_ROT_DEBOUNCE, max7360_rotary->debounce_ms) |
> +		FIELD_PREP(MAX7360_ROT_INTCNT, 1) | MAX7360_ROT_INTCNT_DLY;

Indentation is incorrect.

> +	error = regmap_write(max7360_rotary->regmap, MAX7360_REG_RTRCFG, val);
> +	if (error)
> +		dev_err(dev, "Failed to set max7360 rotary encoder configuration\n");
> +
> +	return error;
> +}

...

> +static int max7360_rotary_probe(struct platform_device *pdev)
> +{
> +	struct max7360_rotary *max7360_rotary;
> +	struct device *dev = &pdev->dev;
> +	struct input_dev *input;
> +	struct regmap *regmap;
> +	int irq;
> +	int error;
> +
> +	regmap = dev_get_regmap(dev->parent, NULL);
> +	if (!regmap)
> +		dev_err_probe(dev, -ENODEV, "Could not get parent regmap\n");

Missing return. Copy'n'paste error over all drivers?

> +	irq = fwnode_irq_get_byname(dev_fwnode(dev->parent), "inti");
> +	if (irq < 0)
> +		return dev_err_probe(dev, irq, "Failed to get IRQ\n");
> +
> +	max7360_rotary = devm_kzalloc(dev, sizeof(*max7360_rotary), GFP_KERNEL);
> +	if (!max7360_rotary)
> +		return -ENOMEM;
> +
> +	max7360_rotary->regmap = regmap;
> +
> +	device_property_read_u32(dev->parent, "linux,axis", &max7360_rotary->axis);
> +	max7360_rotary->rollover = device_property_read_bool(dev->parent,
> +							     "rotary-encoder,rollover");
> +	max7360_rotary->relative_axis =
> +		device_property_read_bool(dev->parent, "rotary-encoder,relative-axis");
> +
> +	error = device_property_read_u32(dev->parent, "rotary-encoder,steps",
> +					 &max7360_rotary->steps);
> +	if (error)
> +		max7360_rotary->steps = MAX7360_ROTARY_DEFAULT_STEPS;
> +
> +	device_property_read_u32(dev->parent, "rotary-debounce-delay-ms",
> +				 &max7360_rotary->debounce_ms);
> +	if (max7360_rotary->debounce_ms > MAX7360_ROT_DEBOUNCE_MAX)
> +		return dev_err_probe(dev, -EINVAL, "Invalid debounce timing: %u\n",
> +				     max7360_rotary->debounce_ms);
> +
> +	input = devm_input_allocate_device(dev);
> +	if (!input)
> +		return -ENOMEM;
> +
> +	max7360_rotary->input = input;
> +
> +	input->id.bustype = BUS_I2C;
> +	input->name = pdev->name;
> +
> +	if (max7360_rotary->relative_axis)
> +		input_set_capability(input, EV_REL, max7360_rotary->axis);
> +	else
> +		input_set_abs_params(input, max7360_rotary->axis, 0, max7360_rotary->steps, 0, 1);
> +
> +	error = devm_request_threaded_irq(dev, irq, NULL, max7360_rotary_irq,
> +					  IRQF_ONESHOT | IRQF_SHARED,
> +					  "max7360-rotary", max7360_rotary);
> +	if (error)
> +		return dev_err_probe(dev, error, "Failed to register interrupt\n");
> +
> +	error = input_register_device(input);
> +	if (error)
> +		return dev_err_probe(dev, error, "Could not register input device\n");
> +
> +	error = max7360_rotary_hw_init(max7360_rotary);
> +	if (error)
> +		return dev_err_probe(dev, error, "Failed to initialize max7360 rotary\n");
> +
> +	device_init_wakeup(dev, true);
> +	error = dev_pm_set_wake_irq(dev, irq);
> +	if (error)
> +		dev_warn(dev, "Failed to set up wakeup irq: %d\n", error);
> +
> +	return 0;
> +}
> +
> +static void max7360_rotary_remove(struct platform_device *pdev)
> +{
> +	dev_pm_clear_wake_irq(&pdev->dev);

Shouldn't be here

	device_init_wakeup(dev, false);

?

> +}

-- 
With Best Regards,
Andy Shevchenko