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Message-ID: <d6463018-ebdf-30b2-ce0e-f2b5198847f1@wanadoo.fr>
Date:   Thu, 23 Mar 2023 21:18:32 +0100
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Subject: Re: [PATCH v2 2/2] leds: max597x: Add support for max597x
Content-Language: fr
To:     Naresh Solanki <naresh.solanki@9elements.com>,
        Lee Jones <lee@kernel.org>, Pavel Machek <pavel@ucw.cz>
Cc:     Patrick Rudolph <patrick.rudolph@9elements.com>,
        linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org
References: <20230323194550.1914725-1-Naresh.Solanki@9elements.com>
 <20230323194550.1914725-2-Naresh.Solanki@9elements.com>
From:   Christophe JAILLET <christophe.jaillet@wanadoo.fr>
In-Reply-To: <20230323194550.1914725-2-Naresh.Solanki@9elements.com>
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Le 23/03/2023 à 20:45, Naresh Solanki a écrit :
> From: Patrick Rudolph <patrick.rudolph@9elements.com>
> 
> max597x is hot swap controller with indicator LED support.
> This driver uses DT property to configure led during boot time &
> also provide the LED control in sysfs.
> 
> DTS example:
>      i2c {
>          #address-cells = <1>;
>          #size-cells = <0>;
>          regulator@3a {
>              compatible = "maxim,max5978";
>              reg = <0x3a>;
>              vss1-supply = <&p3v3>;
> 
>              regulators {
>                  sw0_ref_0: sw0 {
>                      shunt-resistor-micro-ohms = <12000>;
>                  };
>              };
> 
>              leds {
>                  #address-cells = <1>;
>                  #size-cells = <0>;
>                  led@0 {
>                      reg = <0>;
>                      label = "led0";
>                      default-state = "on";
>                  };
>                  led@1 {
>                      reg = <1>;
>                      label = "led1";
>                      default-state = "on";
>                  };
>              };
>          };
>      };
> 
> Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
> Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> ...
> Changes in V2:
> - Fix regmap update
> - Remove devm_kfree
> - Remove default-state
> - Add example dts in commit message
> - Fix whitespace in Kconfig
> - Fix comment
> ---
>   drivers/leds/Kconfig        |  11 ++++
>   drivers/leds/Makefile       |   1 +
>   drivers/leds/leds-max597x.c | 112 ++++++++++++++++++++++++++++++++++++
>   3 files changed, 124 insertions(+)
>   create mode 100644 drivers/leds/leds-max597x.c
> 
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index 9dbce09eabac..ec2b731ae545 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -590,6 +590,17 @@ config LEDS_ADP5520
>   	  To compile this driver as a module, choose M here: the module will
>   	  be called leds-adp5520.
>   
> +config LEDS_MAX597X
> +	tristate "LED Support for Maxim 597x"
> +	depends on LEDS_CLASS
> +	depends on MFD_MAX597X
> +	help
> +	  This option enables support for the Maxim 597x smart switch indication LEDs
> +	  via the I2C bus.
> +
> +	  To compile this driver as a module, choose M here: the module will
> +	  be called max597x-led.

leds-max597x?

> +
>   config LEDS_MC13783
>   	tristate "LED Support for MC13XXX PMIC"
>   	depends on LEDS_CLASS
> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> index d30395d11fd8..da1192e40268 100644
> --- a/drivers/leds/Makefile
> +++ b/drivers/leds/Makefile
> @@ -53,6 +53,7 @@ obj-$(CONFIG_LEDS_LP8501)		+= leds-lp8501.o
>   obj-$(CONFIG_LEDS_LP8788)		+= leds-lp8788.o
>   obj-$(CONFIG_LEDS_LP8860)		+= leds-lp8860.o
>   obj-$(CONFIG_LEDS_LT3593)		+= leds-lt3593.o
> +obj-$(CONFIG_LEDS_MAX597X)		+= leds-max597x.o
>   obj-$(CONFIG_LEDS_MAX77650)		+= leds-max77650.o
>   obj-$(CONFIG_LEDS_MAX8997)		+= leds-max8997.o
>   obj-$(CONFIG_LEDS_MC13783)		+= leds-mc13783.o
> diff --git a/drivers/leds/leds-max597x.c b/drivers/leds/leds-max597x.c
> new file mode 100644
> index 000000000000..3e1747c8693e
> --- /dev/null
> +++ b/drivers/leds/leds-max597x.c
> @@ -0,0 +1,112 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Device driver for leds in MAX5970 and MAX5978 IC
> + *
> + * Copyright (c) 2022 9elements GmbH
> + *
> + * Author: Patrick Rudolph <patrick.rudolph@9elements.com>
> + */
> +
> +#include <linux/leds.h>
> +#include <linux/mfd/max597x.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +#define ldev_to_maxled(c)       container_of(c, struct max597x_led, led)
> +
> +struct max597x_led {
> +	struct regmap *regmap;
> +	struct led_classdev led;
> +	unsigned int index;
> +};
> +
> +static int max597x_led_set_brightness(struct led_classdev *cdev,
> +				      enum led_brightness brightness)
> +{
> +	struct max597x_led *led = ldev_to_maxled(cdev);
> +	int ret, val = 0;
> +
> +	if (!led || !led->regmap)
> +		return -ENODEV;
> +
> +	val = !brightness ? BIT(led->index) : 0;
> +	ret = regmap_update_bits(led->regmap, MAX5970_REG_LED_FLASH, BIT(led->index), val);
> +	if (ret < 0)
> +		dev_err(cdev->dev, "failed to set brightness %d\n", ret);
> +	return ret;
> +}
> +
> +static int max597x_setup_led(struct device *dev, struct regmap *regmap, struct device_node *nc,
> +			     u32 reg)
> +{
> +	struct max597x_led *led;
> +	int ret = 0;

Nit: useless "= 0"

> +
> +	led = devm_kzalloc(dev, sizeof(struct max597x_led),
> +			   GFP_KERNEL);
> +	if (!led)
> +		return -ENOMEM;
> +
> +	if (of_property_read_string(nc, "label", &led->led.name))
> +		led->led.name = nc->name;
> +
> +	led->led.max_brightness = 1;
> +	led->led.brightness_set_blocking = max597x_led_set_brightness;
> +	led->led.default_trigger = "none";
> +	led->index = reg;
> +	led->regmap = regmap;
> +	ret = led_classdev_register(dev, &led->led);

devm_led_classdev_register?

> +	if (ret)
> +		dev_err(dev, "Error in initializing led %s", led->led.name);
> +
> +	return ret;
> +}
> +
> +static int max597x_led_probe(struct platform_device *pdev)
> +{
> +	struct device_node *np = dev_of_node(pdev->dev.parent);
> +	struct regmap *regmap = dev_get_regmap(pdev->dev.parent, NULL);
> +	struct device_node *led_node;
> +	struct device_node *child;
> +	int ret = 0;
> +
> +	if (!regmap)
> +		return -EPROBE_DEFER;
> +
> +	led_node = of_get_child_by_name(np, "leds");
> +	if (!led_node)
> +		return -ENODEV;
> +
> +	for_each_available_child_of_node(led_node, child) {
> +		u32 reg;
> +
> +		if (of_property_read_u32(child, "reg", &reg))
> +			continue;
> +
> +		if (reg >= MAX597X_NUM_LEDS) {
> +			dev_err(&pdev->dev, "invalid LED (%u >= %d)\n", reg,
> +				MAX597X_NUM_LEDS);
> +			continue;
> +		}
> +
> +		ret = max597x_setup_led(&pdev->dev, regmap, child, reg);
> +		if (ret < 0)
> +			of_node_put(child);

This of_node_put() looks odd to me.
"return ret;" or "break;" missing ?

> +	}
> +
> +	return ret;
> +}
> +
> +static struct platform_driver max597x_led_driver = {
> +	.driver = {
> +		.name = "max597x-led",
> +	},
> +	.probe = max597x_led_probe,
> +};
> +
> +module_platform_driver(max597x_led_driver);
> +
> +MODULE_AUTHOR("Patrick Rudolph <patrick.rudolph@9elements.com>");
> +MODULE_DESCRIPTION("MAX5970_hot-swap controller driver");
> +MODULE_LICENSE("GPL");