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

From: Daniel Thompson
Date: Thu Mar 08 2018 - 12:51:44 EST


On 08/03/18 17:29, Andrey Smirnov wrote:
On Thu, Mar 8, 2018 at 8:58 AM, Daniel Thompson
<daniel.thompson@xxxxxxxxxx> 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@xxxxxxxxxx>
Cc: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
Cc: Jingoo Han <jingoohan1@xxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: Chris Healy <cphealy@xxxxxxxxx>
Cc: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
Cc: Aleksander Morgado <aleksander@xxxxxxxxxxxxx>
Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
---
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@xxxxxxxxxx>


Daniel.