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authorLinus Walleij <linus.walleij@linaro.org>2016-06-16 12:36:13 +0300
committerTomi Valkeinen <tomi.valkeinen@ti.com>2016-08-11 17:54:52 +0300
commitc38162be301d59278f568e0b34be31915b6fe3bb (patch)
tree8ec2788c7e44bf7cda5b2a4e7c4de8efec08c503 /drivers/video
parent1d1e56f4140d0af98f7c232fa315e010cd532ccc (diff)
downloadlinux-c38162be301d59278f568e0b34be31915b6fe3bb.tar.xz
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>
Diffstat (limited to 'drivers/video')
-rw-r--r--drivers/video/fbdev/Kconfig4
-rw-r--r--drivers/video/fbdev/amba-clcd.c40
2 files changed, 43 insertions, 1 deletions
diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
index 88b008fb8a4e..9b9a76b82c04 100644
--- a/drivers/video/fbdev/Kconfig
+++ b/drivers/video/fbdev/Kconfig
@@ -284,12 +284,14 @@ config FB_PM2_FIFO_DISCONNECT
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 9b158869cb89..52a33d3926ac 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 @@ static void clcdfb_disable(struct clcd_fb *fb)
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 @@ static void clcdfb_enable(struct clcd_fb *fb, u32 cntl)
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 @@ static int clcdfb_snprintf_mode(char *buf, int size, struct fb_videomode *mode)
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 @@ static int clcdfb_of_init_display(struct clcd_fb *fb)
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;