linux-kernel - Re: [PATCH] auxdisplay: ht16k33: Make use of device properties

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Date:   Wed, 15 Sep 2021 19:44:45 +0300
From:   Andy Shevchenko <andy.shevchenko@...il.com>
To:     Geert Uytterhoeven <geert@...ux-m68k.org>
Cc:     Robin van der Gracht <robin@...tonic.nl>,
        Miguel Ojeda <ojeda@...nel.org>,
        Marek Behún <kabel@...nel.org>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] auxdisplay: ht16k33: Make use of device properties

On Tue, Sep 14, 2021 at 5:42 PM Geert Uytterhoeven <geert@...ux-m68k.org> wrote:
>
> The device property API allows drivers to gather device resources from
> different sources, such as ACPI, and lift the dependency on Device Tree.
> Convert the driver to unleash the power of the device property API.


With or without the nit-pick below
Reviewed-by: Andy Shevchenko <andy.shevchenko@...il.com>

> Suggested-by: Marek Behún <kabel@...nel.org>
> Signed-off-by: Geert Uytterhoeven <geert@...ux-m68k.org>
> ---
> Compile-tested only for the !OF case.
>
> This depends on "[PATCH v6 00/19] auxdisplay: ht16k33: Add character display
> support"
> (https://lore.kernel.org/r/20210914143835.511051-1-geert@linux-m68k.org)
>
>  drivers/auxdisplay/Kconfig   |  2 +-
>  drivers/auxdisplay/ht16k33.c | 25 +++++++++++--------------
>  2 files changed, 12 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/auxdisplay/Kconfig b/drivers/auxdisplay/Kconfig
> index e32ef7f9945d49b2..64012cda4d126707 100644
> --- a/drivers/auxdisplay/Kconfig
> +++ b/drivers/auxdisplay/Kconfig
> @@ -169,7 +169,7 @@ config IMG_ASCII_LCD
>
>  config HT16K33
>         tristate "Holtek Ht16K33 LED controller with keyscan"
> -       depends on FB && OF && I2C && INPUT
> +       depends on FB && I2C && INPUT
>         select FB_SYS_FOPS
>         select FB_SYS_FILLRECT
>         select FB_SYS_COPYAREA
> diff --git a/drivers/auxdisplay/ht16k33.c b/drivers/auxdisplay/ht16k33.c
> index 89ee5b4b3dfccb68..e5b810e37e0337a6 100644
> --- a/drivers/auxdisplay/ht16k33.c
> +++ b/drivers/auxdisplay/ht16k33.c
> @@ -12,7 +12,7 @@
>  #include <linux/module.h>
>  #include <linux/interrupt.h>
>  #include <linux/i2c.h>
> -#include <linux/of.h>
> +#include <linux/property.h>
>  #include <linux/fb.h>
>  #include <linux/slab.h>
>  #include <linux/backlight.h>
> @@ -481,15 +481,13 @@ static int ht16k33_led_probe(struct device *dev, struct led_classdev *led,
>                              unsigned int brightness)
>  {
>         struct led_init_data init_data = {};
> -       struct device_node *node;
>         int err;
>
>         /* The LED is optional */
> -       node = of_get_child_by_name(dev->of_node, "led");
> -       if (!node)
> +       init_data.fwnode = device_get_named_child_node(dev, "led");
> +       if (!init_data.fwnode)
>                 return 0;
>
> -       init_data.fwnode = of_fwnode_handle(node);
>         init_data.devicename = "auxdisplay";
>         init_data.devname_mandatory = true;
>
> @@ -510,7 +508,6 @@ static int ht16k33_keypad_probe(struct i2c_client *client,
>                                 struct ht16k33_keypad *keypad)
>  {
>         struct device *dev = &client->dev;
> -       struct device_node *node = dev->of_node;
>         u32 rows = HT16K33_MATRIX_KEYPAD_MAX_ROWS;
>         u32 cols = HT16K33_MATRIX_KEYPAD_MAX_COLS;
>         int err;
> @@ -529,11 +526,11 @@ static int ht16k33_keypad_probe(struct i2c_client *client,
>         keypad->dev->open = ht16k33_keypad_start;
>         keypad->dev->close = ht16k33_keypad_stop;
>
> -       if (!of_get_property(node, "linux,no-autorepeat", NULL))
> +       if (!device_property_present(dev, "linux,no-autorepeat"))

If it's boolean property one may use device_property_read_bool()...

>                 __set_bit(EV_REP, keypad->dev->evbit);

...or put it as a parameter to __assign_bit(), for example.

>
> -       err = of_property_read_u32(node, "debounce-delay-ms",
> -                                  &keypad->debounce_ms);
> +       err = device_property_read_u32(dev, "debounce-delay-ms",
> +                                      &keypad->debounce_ms);
>         if (err) {
>                 dev_err(dev, "key debounce delay not specified\n");
>                 return err;
> @@ -620,8 +617,8 @@ static int ht16k33_fbdev_probe(struct device *dev, struct ht16k33_priv *priv,
>                 goto err_fbdev_buffer;
>         }
>
> -       err = of_property_read_u32(dev->of_node, "refresh-rate-hz",
> -                                  &fbdev->refresh_rate);
> +       err = device_property_read_u32(dev, "refresh-rate-hz",
> +                                      &fbdev->refresh_rate);
>         if (err) {
>                 dev_err(dev, "refresh rate not specified\n");
>                 goto err_fbdev_info;
> @@ -727,8 +724,8 @@ static int ht16k33_probe(struct i2c_client *client)
>         if (err)
>                 return err;
>
> -       err = of_property_read_u32(dev->of_node, "default-brightness-level",
> -                                  &dft_brightness);
> +       err = device_property_read_u32(dev, "default-brightness-level",
> +                                      &dft_brightness);
>         if (err) {
>                 dft_brightness = MAX_BRIGHTNESS;
>         } else if (dft_brightness > MAX_BRIGHTNESS) {
> @@ -816,7 +813,7 @@ static struct i2c_driver ht16k33_driver = {
>         .remove         = ht16k33_remove,
>         .driver         = {
>                 .name           = DRIVER_NAME,
> -               .of_match_table = of_match_ptr(ht16k33_of_match),
> +               .of_match_table = ht16k33_of_match,
>         },
>         .id_table = ht16k33_i2c_match,
>  };
> --
> 2.25.1
>


-- 
With Best Regards,
Andy Shevchenko