video: ARM CLCD: backlight support for OF
If the device is probed from device tree, we can support
backlight. This is used with some systems such as the
ST Microelectronics Nomadik.
We have to add HAS_IOMEM to the dependencies of CLCD since
the backlight class device will now be selected, and if it
gets selected on an arch that does not have IOMEM,
compilation will fail.
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
index 88b008f..9b9a76b 100644
--- a/drivers/video/fbdev/Kconfig
+++ b/drivers/video/fbdev/Kconfig
@@ -284,12 +284,14 @@
config FB_ARMCLCD
tristate "ARM PrimeCell PL110 support"
depends on ARM || ARM64 || COMPILE_TEST
- depends on FB && ARM_AMBA
+ depends on FB && ARM_AMBA && HAS_IOMEM
select FB_CFB_FILLRECT
select FB_CFB_COPYAREA
select FB_CFB_IMAGEBLIT
select FB_MODE_HELPERS if OF
select VIDEOMODE_HELPERS if OF
+ select BACKLIGHT_LCD_SUPPORT if OF
+ select BACKLIGHT_CLASS_DEVICE if OF
help
This framebuffer device driver is for the ARM PrimeCell PL110
Colour LCD controller. ARM PrimeCells provide the building
diff --git a/drivers/video/fbdev/amba-clcd.c b/drivers/video/fbdev/amba-clcd.c
index 9b15886..52a33d3 100644
--- a/drivers/video/fbdev/amba-clcd.c
+++ b/drivers/video/fbdev/amba-clcd.c
@@ -30,6 +30,7 @@
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_graph.h>
+#include <linux/backlight.h>
#include <video/display_timing.h>
#include <video/of_display_timing.h>
#include <video/videomode.h>
@@ -71,6 +72,11 @@
if (fb->board->disable)
fb->board->disable(fb);
+ if (fb->panel->backlight) {
+ fb->panel->backlight->props.power = FB_BLANK_POWERDOWN;
+ backlight_update_status(fb->panel->backlight);
+ }
+
val = readl(fb->regs + fb->off_cntl);
if (val & CNTL_LCDPWR) {
val &= ~CNTL_LCDPWR;
@@ -117,6 +123,14 @@
writel(cntl, fb->regs + fb->off_cntl);
/*
+ * Turn on backlight
+ */
+ if (fb->panel->backlight) {
+ fb->panel->backlight->props.power = FB_BLANK_UNBLANK;
+ backlight_update_status(fb->panel->backlight);
+ }
+
+ /*
* finally, enable the interface.
*/
if (fb->board->enable)
@@ -576,6 +590,28 @@
mode->refresh);
}
+static int clcdfb_of_get_backlight(struct device_node *endpoint,
+ struct clcd_panel *clcd_panel)
+{
+ struct device_node *panel;
+ struct device_node *backlight;
+
+ panel = of_graph_get_remote_port_parent(endpoint);
+ if (!panel)
+ return -ENODEV;
+
+ /* Look up the optional backlight phandle */
+ backlight = of_parse_phandle(panel, "backlight", 0);
+ if (backlight) {
+ clcd_panel->backlight = of_find_backlight_by_node(backlight);
+ of_node_put(backlight);
+
+ if (!clcd_panel->backlight)
+ return -EPROBE_DEFER;
+ }
+ return 0;
+}
+
static int clcdfb_of_get_mode(struct device *dev, struct device_node *endpoint,
struct fb_videomode *mode)
{
@@ -662,6 +698,10 @@
if (!endpoint)
return -ENODEV;
+ err = clcdfb_of_get_backlight(endpoint, fb->panel);
+ if (err)
+ return err;
+
err = clcdfb_of_get_mode(&fb->dev->dev, endpoint, &fb->panel->mode);
if (err)
return err;
diff --git a/include/linux/amba/clcd.h b/include/linux/amba/clcd.h
index e82e3ee..e64c1cc 100644
--- a/include/linux/amba/clcd.h
+++ b/include/linux/amba/clcd.h
@@ -93,6 +93,8 @@
CLCD_CAP_ALL = CLCD_CAP_BGR | CLCD_CAP_RGB,
};
+struct backlight_device;
+
struct clcd_panel {
struct fb_videomode mode;
signed short width; /* width in mm */
@@ -105,6 +107,7 @@
fixedtimings:1,
grayscale:1;
unsigned int connector;
+ struct backlight_device *backlight;
};
struct clcd_regs {