Re: [PATCH] leds: max5970: Add support for max5970

[Naresh Solanki]

Hi,


On Thu, 24 Aug 2023 at 03:22, Christophe JAILLET
<christophe.jaillet@xxxxxxxxxx> wrote:
>
> Le 23/08/2023 à 23:23, Naresh Solanki a écrit :
> > From: Patrick Rudolph <patrick.rudolph@xxxxxxxxxxxxx>
> >
> > The MAX5970 is hot swap controller and has 4 indication LED.
> >
> > Signed-off-by: Patrick Rudolph <patrick.rudolph@xxxxxxxxxxxxx>
> > Signed-off-by: Naresh Solanki <Naresh.Solanki@xxxxxxxxxxxxx>
> > ---
> >   drivers/leds/Kconfig        |  11 +++
> >   drivers/leds/Makefile       |   1 +
> >   drivers/leds/leds-max5970.c | 129 ++++++++++++++++++++++++++++++++++++
> >   3 files changed, 141 insertions(+)
> >   create mode 100644 drivers/leds/leds-max5970.c
> >
> > diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> > index b92208eccdea..03ef527cc545 100644
> > --- a/drivers/leds/Kconfig
> > +++ b/drivers/leds/Kconfig
> > @@ -637,6 +637,17 @@ config LEDS_ADP5520
> >         To compile this driver as a module, choose M here: the module will
> >         be called leds-adp5520.
> >
> > +config LEDS_MAX5970
> > +     tristate "LED Support for Maxim 5970"
> > +     depends on LEDS_CLASS
> > +     depends on MFD_MAX5970
> > +     help
> > +       This option enables support for the Maxim MAX5970 & MAX5978 smart
> > +       switch indication LEDs via the I2C bus.
> > +
> > +       To compile this driver as a module, choose M here: the module will
> > +       be called leds-max5970.
> > +
> >   config LEDS_MC13783
> >       tristate "LED Support for MC13XXX PMIC"
> >       depends on LEDS_CLASS
> > diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> > index d7348e8bc019..6eaee0a753c6 100644
> > --- a/drivers/leds/Makefile
> > +++ b/drivers/leds/Makefile
> > @@ -56,6 +56,7 @@ 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-$(CONFIG_LEDS_MAX5970)           += leds-max5970.o
> >   obj-$(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-max5970.c b/drivers/leds/leds-max5970.c
> > new file mode 100644
> > index 000000000000..5be1b927f39e
> > --- /dev/null
> > +++ b/drivers/leds/leds-max5970.c
> > @@ -0,0 +1,129 @@
> > +// 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@xxxxxxxxxxxxx>
> > + */
> > +
> > +#include <linux/leds.h>
> > +#include <linux/mfd/max5970.h>
> > +#include <linux/of.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/regmap.h>
> > +
> > +#define ldev_to_maxled(c)       container_of(c, struct max5970_led, cdev)
> > +
> > +struct max5970_led {
> > +     struct device *dev;
> > +     struct regmap *regmap;
> > +     struct led_classdev cdev;
> > +     unsigned int index;
> > +};
> > +
> > +static int max5970_led_set_brightness(struct led_classdev *cdev,
> > +                                   enum led_brightness brightness)
> > +{
> > +     struct max5970_led *ddata = ldev_to_maxled(cdev);
> > +     int ret, val;
> > +
> > +     if (!ddata->regmap)
> > +             return -ENODEV;
> > +
> > +     /* Set/clear corresponding bit for given led index */
> > +     val = !brightness ? BIT(ddata->index) : 0;
> > +
> > +     ret = regmap_update_bits(ddata->regmap, MAX5970_REG_LED_FLASH, BIT(ddata->index), val);
> > +     if (ret < 0)
> > +             dev_err(cdev->dev, "failed to set brightness %d", ret);
> > +
> > +     return ret;
> > +}
> > +
> > +static int max5970_setup_led(struct max5970_led *ddata, struct regmap *regmap,
> > +                          struct device_node *nc, u32 reg)
> > +{
> > +     int ret;
> > +
> > +     if (of_property_read_string(nc, "label", &ddata->cdev.name))
> > +             ddata->cdev.name = nc->name;
> > +
> > +     ddata->cdev.max_brightness = 1;
> > +     ddata->cdev.brightness_set_blocking = max5970_led_set_brightness;
> > +     ddata->cdev.default_trigger = "none";
> > +
> > +     ret = devm_led_classdev_register(ddata->dev, &ddata->cdev);
> > +     if (ret)
> > +             dev_err(ddata->dev, "Error initializing LED %s", ddata->cdev.name);
> > +
> > +     return ret;
> > +}
> > +
> > +static int max5970_led_probe(struct platform_device *pdev)
> > +{
> > +     struct device *dev = &pdev->dev;
> > +     struct device_node *np = dev_of_node(dev->parent);
> > +     struct regmap *regmap;
> > +     struct device_node *led_node;
> > +     struct device_node *child;
> > +     struct max5970_led *ddata[MAX5970_NUM_LEDS];
> > +     int ret = -ENODEV, num_leds = 0;
> > +
> > +     regmap = dev_get_regmap(pdev->dev.parent, NULL);
> > +     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 >= MAX5970_NUM_LEDS) {
> > +                     dev_err(dev, "invalid LED (%u >= %d)\n", reg, MAX5970_NUM_LEDS);
> > +                     continue;
> > +             }
> > +
> > +             ddata[num_leds] = devm_kzalloc(dev, sizeof(struct max5970_led), GFP_KERNEL);
> > +             if (!ddata[num_leds]) {
> > +                     ret = -ENOMEM;
>
> Hi,
>
> Should we have a "of_node_put(child);" here?
Ack. Will add in next revision.
>
> > +                     goto exit;
> > +             }
> > +
> > +             ddata[num_leds]->index = reg;
> > +             ddata[num_leds]->regmap = regmap;
> > +             ddata[num_leds]->dev = dev;
> > +
> > +             ret = max5970_setup_led(ddata[num_leds], regmap, child, reg);
> > +             if (ret < 0) {
> > +                     dev_err(dev, "Failed to initialize LED %u\n", reg);
>
> Should we have a "of_node_put(child);" here?
Ack.
>
> > +                     goto exit;
> > +             }
> > +             num_leds++;
> > +     }
> > +
> > +     return ret;
> > +
> > +exit:
> > +     for (int j = 0; j < num_leds; j++)
> > +             devm_led_classdev_unregister(dev, &ddata[j]->cdev);
>
> Is it really needed?
> There is no equivalent call in a .remove function and
> devm_led_classdev_register() is used.
>
> Shouldn't the unregister step be done automatically by the framework?
Ack. Will be removed in the next revision.
Instead of using goto exit, will return with the error code.

Regards,
Naresh
>
> CJ
>
> > +
> > +     return ret;
> > +}
> > +
> > +static struct platform_driver max5970_led_driver = {
> > +     .driver = {
> > +             .name = "max5970-led",
> > +     },
> > +     .probe = max5970_led_probe,
> > +};
> > +
> > +module_platform_driver(max5970_led_driver);
> > +MODULE_AUTHOR("Patrick Rudolph <patrick.rudolph@xxxxxxxxxxxxx>");
> > +MODULE_DESCRIPTION("MAX5970_hot-swap controller LED driver");
> > +MODULE_LICENSE("GPL");
> >
> > base-commit: baca986e1f2c31f8e4b2a6d99d47c3bc844033e8
>