Hi,
On 5/12/24 9:35 PM, Andy Shevchenko wrote:
> On Sun, May 12, 2024 at 7:24 PM Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
>>
>> Dell All In One (AIO) models released after 2017 use a backlight controller
>> board connected to an UART.
>>
>> In DSDT this uart port will be defined as:
>>
>> Name (_HID, "DELL0501")
>> Name (_CID, EisaId ("PNP0501")
>>
>> Instead of having a separate ACPI device with an UartSerialBusV2() resource
>> to model the backlight-controller, which would be the standard way to do
>> this.
>>
>> The acpi_quirk_skip_serdev_enumeration() has special handling for this
>> and it will make the serial port code create a serdev controller device
>> for the UART instead of a /dev/ttyS0 char-dev. It will also create
>> a dell-uart-backlight driver platform device for this driver to bind too.
>>
>> This new kernel module contains 2 drivers for this:
>>
>> 1. A simple platform driver which creates the actual serdev device
>> (with the serdev controller device as parent)
>>
>> 2. A serdev driver for the created serdev device which exports
>> the backlight functionality uses a standard backlight class device.
>
> ...
>
>> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>
> How is this being used?
#include "../serdev_helpers.h"
uses this.
>
> ...
>
>> +#include <linux/acpi.h>
>
> + array_size.h
>
>> +#include <linux/backlight.h>
>> +#include <linux/delay.h>
>
> + device.h // devm_kzalloc(), dev_err() et al.
>
> + err.h
>
>> +#include <linux/module.h>
>> +#include <linux/mutex.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/serdev.h>
>
> + string.h
> + types.h
>
>> +#include <linux/wait.h>
Ack, all includes added, thanks.
<snip>
>> +static int dell_uart_update_status(struct backlight_device *bd)
>> +{
>> + struct dell_uart_backlight *dell_bl = bl_get_data(bd);
>> + int ret;
>> +
>> + ret = dell_uart_set_brightness(dell_bl, bd->props.brightness);
>> + if (ret)
>> + return ret;
>> +
>> + if (bd->props.power != dell_uart_get_bl_power(dell_bl))
>> + ret = dell_uart_set_bl_power(dell_bl, bd->props.power);
>
> return ...;
>
>> + return ret;
>
> return 0;
>
> ?
Ack, fixed for v2.
Regards,
Hans
