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

[Naresh Solanki]

Hi

On Thu, 24 Aug 2023 at 15:29, Patrick Rudolph
<patrick.rudolph@xxxxxxxxxxxxx> wrote:
>
> On Wed, Aug 23, 2023 at 11:23 PM Naresh Solanki
> <naresh.solanki@xxxxxxxxxxxxx> wrote:
> >
> > 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;
> Can this ever happen? Looks like this conditions is always false.
Yes. Will be removed in the next revision.
>
> > +
> > +       /* 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)
> > +{
> regmap and reg is not used within this function.
> I don't see the need for this function, just add those 8 lines in the
> loop below.
Ack.
>
> > +       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;
> > +                       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);
> > +                       goto exit;
> > +               }
> > +               num_leds++;
> > +       }
> > +
> > +       return ret;
> > +
> > +exit:
> > +       for (int j = 0; j < num_leds; j++)
> > +               devm_led_classdev_unregister(dev, &ddata[j]->cdev);
> > +
> > +       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>");
>
> You might want to put your name here, as you've rewritten the complete
> driver code.
ok.

Regards,
Naresh

>
> > +MODULE_DESCRIPTION("MAX5970_hot-swap controller LED driver");
> > +MODULE_LICENSE("GPL");
> >
> > base-commit: baca986e1f2c31f8e4b2a6d99d47c3bc844033e8
> > --
> > 2.41.0
> >