linux-kernel - Re: [PATCH v3 13/23] input: add max77705 haptic driver

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Message-ID: <da34df13-bc57-4142-b558-88a6628d8b81@kernel.org>
Date: Thu, 20 Jun 2024 18:04:57 +0200
From: Krzysztof Kozlowski <krzk@...nel.org>
To: Dzmitry Sankouski <dsankouski@...il.com>,
 Sebastian Reichel <sre@...nel.org>, Bjorn Andersson <andersson@...nel.org>,
 Michael Turquette <mturquette@...libre.com>, Stephen Boyd
 <sboyd@...nel.org>, Neil Armstrong <neil.armstrong@...aro.org>,
 Jessica Zhang <quic_jesszhan@...cinc.com>, Sam Ravnborg <sam@...nborg.org>,
 Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
 Maxime Ripard <mripard@...nel.org>, Thomas Zimmermann <tzimmermann@...e.de>,
 David Airlie <airlied@...il.com>, Daniel Vetter <daniel@...ll.ch>,
 Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>,
 Conor Dooley <conor+dt@...nel.org>, Lee Jones <lee@...nel.org>,
 Dmitry Torokhov <dmitry.torokhov@...il.com>, Pavel Machek <pavel@....cz>,
 Liam Girdwood <lgirdwood@...il.com>, Mark Brown <broonie@...nel.org>,
 Uwe Kleine-König <ukleinek@...nel.org>,
 Konrad Dybcio <konrad.dybcio@...aro.org>,
 Chanwoo Choi <cw00.choi@...sung.com>, phone-devel@...r.kernel.org
Cc: linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org,
 linux-arm-msm@...r.kernel.org, linux-clk@...r.kernel.org,
 dri-devel@...ts.freedesktop.org, devicetree@...r.kernel.org,
 linux-input@...r.kernel.org, linux-leds@...r.kernel.org,
 linux-pwm@...r.kernel.org, linux-samsung-soc@...r.kernel.org
Subject: Re: [PATCH v3 13/23] input: add max77705 haptic driver

On 18/06/2024 15:59, Dzmitry Sankouski wrote:
> Add support for haptic controller on MAX77705 Multifunction
> device.
> 
> This driver supports external pwm and LRA (Linear Resonant Actuator) motor.
> User can control the haptic device via force feedback framework.
> 
> Signed-off-by: Dzmitry Sankouski <dsankouski@...il.com>
> ---

> +static int max77705_haptic_bias(struct max77705_haptic *haptic, bool on)
> +{
> +	int error;
> +
> +	error = regmap_update_bits(haptic->regmap_haptic,
> +							   MAX77705_PMIC_REG_MAINCTRL1,
> +							   MAX77705_MAINCTRL1_BIASEN_MASK,
> +							   on << MAX77705_MAINCTRL1_BIASEN_SHIFT);
> +
> +	if (error) {
> +		dev_err(haptic->dev, "failed to %s bias: %d\n",
> +			on ? "enable" : "disable", error);
> +		return error;
> +	}
> +
> +	return 0;
> +}
> +
> +static int max77705_haptic_configure(struct max77705_haptic *haptic,
> +				     bool enable)
> +{
> +	unsigned int value, config_reg;
> +	int error;
> +
> +	value = ((haptic->type << MAX77705_CONFIG2_MODE_SHIFT) |
> +		(enable << MAX77705_CONFIG2_MEN_SHIFT) |
> +		(haptic->mode << MAX77705_CONFIG2_HTYP_SHIFT) |
> +		MAX77705_HAPTIC_PWM_DIVISOR_128);
> +	config_reg = MAX77705_PMIC_REG_MCONFIG;
> +
> +	error = regmap_write(haptic->regmap_haptic,
> +			     config_reg, value);
> +	if (error) {
> +		dev_err(haptic->dev,
> +			"failed to update haptic config: %d\n", error);
> +		return error;
> +	}
> +
> +	return 0;
> +}
> +
> +static void max77705_haptic_enable(struct max77705_haptic *haptic)
> +{
> +	int error;
> +
> +	if (haptic->enabled)
> +		return;
> +
> +	error = pwm_enable(haptic->pwm_dev);
> +	if (error) {
> +		dev_err(haptic->dev,
> +			"failed to enable haptic pwm device: %d\n", error);
> +		return;
> +	}
> +
> +	error = max77705_haptic_configure(haptic, true);
> +	if (error)
> +		goto err_enable_config;
> +
> +	haptic->enabled = true;
> +
> +	return;
> +
> +err_enable_config:
> +	pwm_disable(haptic->pwm_dev);
> +}
> +
> +static void max77705_haptic_disable(struct max77705_haptic *haptic)
> +{
> +	int error;
> +
> +	if (!haptic->enabled)
> +		return;
> +
> +	error = max77705_haptic_configure(haptic, false);
> +	if (error)
> +		return;
> +
> +	pwm_disable(haptic->pwm_dev);
> +	haptic->enabled = false;
> +}
> +
> +static void max77705_haptic_play_work(struct work_struct *work)
> +{
> +	struct max77705_haptic *haptic =
> +			container_of(work, struct max77705_haptic, work);
> +	int error;
> +
> +	error = max77705_haptic_set_duty_cycle(haptic);
> +	if (error) {
> +		dev_err(haptic->dev, "failed to set duty cycle: %d\n", error);
> +		return;
> +	}
> +
> +	if (haptic->magnitude)
> +		max77705_haptic_enable(haptic);
> +	else
> +		max77705_haptic_disable(haptic);
> +}
> +
> +static int max77705_haptic_play_effect(struct input_dev *dev, void *data,
> +				       struct ff_effect *effect)
> +{
> +	struct max77705_haptic *haptic = input_get_drvdata(dev);
> +	struct pwm_args pargs;
> +	u64 period_mag_multi;
> +
> +	haptic->magnitude = effect->u.rumble.strong_magnitude;
> +	if (!haptic->magnitude)
> +		haptic->magnitude = effect->u.rumble.weak_magnitude;
> +
> +	/*
> +	 * The magnitude comes from force-feedback interface.
> +	 * The formula to convert magnitude to pwm_duty as follows:
> +	 * - pwm_duty = (magnitude * pwm_period) / MAX_MAGNITUDE(0xFFFF)
> +	 */
> +	pr_info("magnitude: %d(%x)", haptic->magnitude, haptic->magnitude);

Do not use pr_xxx in your drivers. That's a generic comment so please
apply it everywhere. Anyway driver should be silent.


> +	pwm_get_args(haptic->pwm_dev, &pargs);
> +	period_mag_multi = (u64)pargs.period * haptic->magnitude;
> +	haptic->pwm_duty = (unsigned int)(period_mag_multi >>
> +						MAX_MAGNITUDE_SHIFT);
> +
> +	schedule_work(&haptic->work);
> +
> +	return 0;
> +}


> +
> +static DEFINE_SIMPLE_DEV_PM_OPS(max77705_haptic_pm_ops,
> +				max77705_haptic_suspend,
> +				max77705_haptic_resume);
> +
> +static const struct of_device_id of_max77705_haptic_dt_match[] = {
> +	{ .compatible = "maxim,max77705-haptic", },
> +	{ /* sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(of, of_max77705_haptic_dt_match);
> +
> +static struct platform_driver max77705_haptic_driver = {
> +	.driver		= {
> +		.name	= "max77705-haptic",
> +		.pm	= pm_sleep_ptr(&max77705_haptic_pm_ops),
> +		.of_match_table = of_max77705_haptic_dt_match,
> +	},
> +	.probe		= max77705_haptic_probe,
> +	.remove_new	= max77705_haptic_remove,
> +};
> +module_platform_driver(max77705_haptic_driver);
> +
> +MODULE_AUTHOR("Dzmitry Sankouski <dsankouski@...il.com>");
> +MODULE_AUTHOR("Jaewon Kim <jaewon02.kim@...sung.com>");
> +MODULE_AUTHOR("Krzysztof Kozlowski <krzk@...nel.org>");

I doubt that this driver is needed. Everything is copy of max777693.


Best regards,
Krzysztof