linux-kernel - Re: [PATCH v7 04/11] pwm: max7360: Add MAX7360 PWM support

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Message-ID: <aBScGRN-1C81gtC5@smile.fi.intel.com>
Date: Fri, 2 May 2025 13:19:05 +0300
From: Andy Shevchenko <andriy.shevchenko@...el.com>
To: mathieu.dubois-briand@...tlin.com
Cc: Lee Jones <lee@...nel.org>, Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Kamel Bouhara <kamel.bouhara@...tlin.com>,
	Linus Walleij <linus.walleij@...aro.org>,
	Bartosz Golaszewski <brgl@...ev.pl>,
	Dmitry Torokhov <dmitry.torokhov@...il.com>,
	Uwe Kleine-König <ukleinek@...nel.org>,
	Michael Walle <mwalle@...nel.org>, Mark Brown <broonie@...nel.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	"Rafael J. Wysocki" <rafael@...nel.org>,
	Danilo Krummrich <dakr@...nel.org>, devicetree@...r.kernel.org,
	linux-kernel@...r.kernel.org, linux-gpio@...r.kernel.org,
	linux-input@...r.kernel.org, linux-pwm@...r.kernel.org,
	Grégory Clement <gregory.clement@...tlin.com>,
	Thomas Petazzoni <thomas.petazzoni@...tlin.com>
Subject: Re: [PATCH v7 04/11] pwm: max7360: Add MAX7360 PWM support

On Mon, Apr 28, 2025 at 01:57:22PM +0200, mathieu.dubois-briand@...tlin.com wrote:
> From: Kamel Bouhara <kamel.bouhara@...tlin.com>
> 
> Add driver for Maxim Integrated MAX7360 PWM controller, supporting up to
> 8 independent PWM outputs.

...

> +static int max7360_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
> +{
> +	struct regmap *regmap;
> +	int ret;

> +	regmap = pwmchip_get_drvdata(chip);

Just unify this assignment with the definition. Will save you 1 LoC.

> +	ret = regmap_write_bits(regmap, MAX7360_REG_PWMCFG(pwm->hwpwm),
> +				MAX7360_PORT_CFG_COMMON_PWM, 0);
> +	if (ret)
> +		return ret;
> +
> +	return regmap_write_bits(regmap, MAX7360_REG_PORTS, BIT(pwm->hwpwm), BIT(pwm->hwpwm));
> +}

...

> +static int max7360_pwm_round_waveform_fromhw(struct pwm_chip *chip, struct pwm_device *pwm,
> +					     const void *_wfhw, struct pwm_waveform *wf)
> +{
> +	const struct max7360_pwm_waveform *wfhw = _wfhw;
> +
> +	wf->period_length_ns = wfhw->enabled ? MAX7360_PWM_PERIOD_NS : 0;
> +	wf->duty_offset_ns = 0;
> +	wf->duty_length_ns = DIV64_U64_ROUND_UP(wfhw->duty_steps * MAX7360_PWM_PERIOD_NS,

Does the numerator have already 64-bit type? Otherwise (u)int*(u)int will be
just an (u)int.

> +						MAX7360_PWM_MAX_RES);
> +
> +	return 0;
> +}

...

> +static int max7360_pwm_read_waveform(struct pwm_chip *chip,
> +				     struct pwm_device *pwm,
> +				     void *_wfhw)
> +{
> +	struct max7360_pwm_waveform *wfhw = _wfhw;
> +	struct regmap *regmap;
> +	unsigned int val;
> +	int ret;

> +	regmap = pwmchip_get_drvdata(chip);
> +

Save 2 LoCs.

> +	ret = regmap_read(regmap, MAX7360_REG_GPIOCTRL, &val);
> +	if (ret)
> +		return ret;
> +
> +	if (val & BIT(pwm->hwpwm)) {
> +		wfhw->enabled = true;
> +		ret = regmap_read(regmap, MAX7360_REG_PWM(pwm->hwpwm), &val);
> +		if (ret)
> +			return ret;
> +
> +		wfhw->duty_steps = val;
> +	} else {
> +		wfhw->enabled = false;
> +		wfhw->duty_steps = 0;
> +	}
> +
> +	return 0;
> +}

...

> +static int max7360_pwm_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct pwm_chip *chip;
> +	struct regmap *regmap;
> +	int ret;
> +
> +	regmap = dev_get_regmap(dev->parent, NULL);
> +	if (!regmap)
> +		return dev_err_probe(dev, -ENODEV, "could not get parent regmap\n");

> +	device_set_of_node_from_dev(dev, dev->parent);

Probably same comment as per pin control driver case?

> +	chip = devm_pwmchip_alloc(dev, MAX7360_NUM_PWMS, 0);
> +	if (IS_ERR(chip))
> +		return PTR_ERR(chip);
> +	chip->ops = &max7360_pwm_ops;

> +	pwmchip_set_drvdata(chip, regmap);

> +	ret = devm_pwmchip_add(dev, chip);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "failed to add PWM chip\n");
> +
> +	return 0;
> +}

-- 
With Best Regards,
Andy Shevchenko