Re: [PATCH 1/2] backlight: Add RAVE SP backlight driver

[Daniel Thompson <daniel.thompson@linaro.org>]

On 08/03/18 17:29, Andrey Smirnov wrote:
> On Thu, Mar 8, 2018 at 8:58 AM, Daniel Thompson
> <daniel.thompson@linaro.org> wrote:
>> On 07/03/18 02:40, Andrey Smirnov wrote:
>>>
>>> This driver provides access to RAVE SP backlight control
>>> functionality.
>>>
>>> Cc: Lee Jones <lee.jones@linaro.org>
>>> Cc: Daniel Thompson <daniel.thompson@linaro.org>
>>> Cc: Jingoo Han <jingoohan1@gmail.com>
>>> Cc: linux-kernel@vger.kernel.org
>>> Cc: Chris Healy <cphealy@gmail.com>
>>> Cc: Lucas Stach <l.stach@pengutronix.de>
>>> Cc: Aleksander Morgado <aleksander@aleksander.es>
>>> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
>>> ---
>>>    drivers/video/backlight/Kconfig             |  6 +++
>>>    drivers/video/backlight/Makefile            |  1 +
>>>    drivers/video/backlight/rave-sp-backlight.c | 82
>>> +++++++++++++++++++++++++++++
>>>    include/linux/mfd/rave-sp.h                 |  1 +
>>>    4 files changed, 90 insertions(+)
>>>    create mode 100644 drivers/video/backlight/rave-sp-backlight.c
>>>
>>> diff --git a/drivers/video/backlight/Kconfig
>>> b/drivers/video/backlight/Kconfig
>>> index 4e1d2ad50ba1..5d2d0d7e8100 100644
>>> --- a/drivers/video/backlight/Kconfig
>>> +++ b/drivers/video/backlight/Kconfig
>>> @@ -467,6 +467,12 @@ config BACKLIGHT_ARCXCNN
>>>            If you have an ARCxCnnnn family backlight say Y to enable
>>>            the backlight driver.
>>>    +config BACKLIGHT_RAVE_SP
>>> +       tristate "RAVE SP Backlight driver"
>>> +       depends on RAVE_SP_CORE
>>> +       help
>>> +         Support for backlight control on RAVE SP device.
>>> +
>>>    endif # BACKLIGHT_CLASS_DEVICE
>>>      endif # BACKLIGHT_LCD_SUPPORT
>>> diff --git a/drivers/video/backlight/Makefile
>>> b/drivers/video/backlight/Makefile
>>> index 5e28f01c8391..19da71d518bf 100644
>>> --- a/drivers/video/backlight/Makefile
>>> +++ b/drivers/video/backlight/Makefile
>>> @@ -57,3 +57,4 @@ obj-$(CONFIG_BACKLIGHT_TOSA)          += tosa_bl.o
>>>    obj-$(CONFIG_BACKLIGHT_TPS65217)      += tps65217_bl.o
>>>    obj-$(CONFIG_BACKLIGHT_WM831X)                += wm831x_bl.o
>>>    obj-$(CONFIG_BACKLIGHT_ARCXCNN)       += arcxcnn_bl.o
>>> +obj-$(CONFIG_BACKLIGHT_RAVE_SP)                += rave-sp-backlight.o
>>> diff --git a/drivers/video/backlight/rave-sp-backlight.c
>>> b/drivers/video/backlight/rave-sp-backlight.c
>>> new file mode 100644
>>> index 000000000000..62836ba561db
>>> --- /dev/null
>>> +++ b/drivers/video/backlight/rave-sp-backlight.c
>>> @@ -0,0 +1,82 @@
>>> +// SPDX-License-Identifier: GPL-2.0+
>>> +
>>> +/*
>>> + * LCD Backlight driver for RAVE SP
>>> + *
>>> + * Copyright (C) 2018 Zodiac Inflight Innovations
>>> + *
>>> + */
>>> +
>>> +#include <linux/backlight.h>
>>> +#include <linux/kernel.h>
>>> +#include <linux/module.h>
>>> +#include <linux/mfd/rave-sp.h>
>>> +#include <linux/platform_device.h>
>>> +
>>> +#define        RAVE_SP_BACKLIGHT_LCD_EN        BIT(7)
>>> +
>>> +static int rave_sp_backlight_update_status(struct backlight_device *bd)
>>> +{
>>> +       const struct backlight_properties *p = &bd->props;
>>> +       const u8 intensity =
>>> +               (p->power == FB_BLANK_UNBLANK) ? p->brightness : 0;
>>> +       struct rave_sp *sp = dev_get_drvdata(&bd->dev);
>>> +       u8 cmd[] = {
>>> +               [0] = RAVE_SP_CMD_SET_BACKLIGHT,
>>> +               [1] = 0,
>>> +               [2] = intensity ? RAVE_SP_BACKLIGHT_LCD_EN | intensity :
>>> 0,
>>> +               [3] = 0,
>>> +               [4] = 0,
>>> +       };
>>> +
>>> +       return rave_sp_exec(sp, cmd, sizeof(cmd), NULL, 0);
>>> +}
>>> +
>>> +static const struct backlight_ops rave_sp_backlight_ops = {
>>> +       .options        = BL_CORE_SUSPENDRESUME,
>>> +       .update_status  = rave_sp_backlight_update_status,
>>> +};
>>> +
>>> +static struct backlight_properties rave_sp_backlight_props = {
>>> +       .type           = BACKLIGHT_FIRMWARE,
>>
>>
>> I would have thought BACKLIGHT_PLATFORM would be more suitable here.
>> BACKLIGHT_FIRMWARE is used for things like the ACPI backlight driver.
>>
>> Why did you select this one?
>>
> 
> Good point and I don't think I have any justification to choose
> FIRMWARE over PLATFORM, will fix in v2.

Thanks. With that fixed:

Acked-by: Daniel Thompson <daniel.thompson@linaro.org>


Daniel.