ep93xx: Use ioremap for backlight driver
The ep93xx backlight driver uses a single register within the
framebuffer's register space. Currently the backlight driver uses a
static IO mapping for the register since the memory cannot be
requested by both drivers.
Convert the static mapping to use ioremap so that we can remove the
dependency on mach/hardware.h. To do so, we need remove the
request_mem_region from both the backlight and framebuffer drivers,
since whichever driver is loaded second will fail with -EBUSY
otherwise.
A proper fix is still required, and a FIXME comment has been added to
both drivers.
Signed-off-by: Ryan Mallon <rmallon@gmail.com>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Cc: Mika Westerberg <mika.westerberg@iki.fi>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
diff --git a/arch/arm/mach-ep93xx/core.c b/arch/arm/mach-ep93xx/core.c
index b5c1dae..c73e299 100644
--- a/arch/arm/mach-ep93xx/core.c
+++ b/arch/arm/mach-ep93xx/core.c
@@ -682,9 +682,19 @@
.resource = ep93xx_fb_resource,
};
+/* The backlight use a single register in the framebuffer's register space */
+#define EP93XX_RASTER_REG_BRIGHTNESS 0x20
+
+static struct resource ep93xx_bl_resources[] = {
+ DEFINE_RES_MEM(EP93XX_RASTER_PHYS_BASE +
+ EP93XX_RASTER_REG_BRIGHTNESS, 0x04),
+};
+
static struct platform_device ep93xx_bl_device = {
.name = "ep93xx-bl",
.id = -1,
+ .num_resources = ARRAY_SIZE(ep93xx_bl_resources),
+ .resource = ep93xx_bl_resources,
};
/**
diff --git a/drivers/video/backlight/ep93xx_bl.c b/drivers/video/backlight/ep93xx_bl.c
index b62b8b9..08214e1 100644
--- a/drivers/video/backlight/ep93xx_bl.c
+++ b/drivers/video/backlight/ep93xx_bl.c
@@ -17,11 +17,6 @@
#include <linux/fb.h>
#include <linux/backlight.h>
-#include <mach/hardware.h>
-
-#define EP93XX_RASTER_REG(x) (EP93XX_RASTER_BASE + (x))
-#define EP93XX_RASTER_BRIGHTNESS EP93XX_RASTER_REG(0x20)
-
#define EP93XX_MAX_COUNT 255
#define EP93XX_MAX_BRIGHT 255
#define EP93XX_DEF_BRIGHT 128
@@ -35,7 +30,7 @@
{
struct ep93xxbl *ep93xxbl = bl_get_data(bl);
- __raw_writel((brightness << 8) | EP93XX_MAX_COUNT, ep93xxbl->mmio);
+ writel((brightness << 8) | EP93XX_MAX_COUNT, ep93xxbl->mmio);
ep93xxbl->brightness = brightness;
@@ -70,21 +65,29 @@
struct ep93xxbl *ep93xxbl;
struct backlight_device *bl;
struct backlight_properties props;
+ struct resource *res;
ep93xxbl = devm_kzalloc(&dev->dev, sizeof(*ep93xxbl), GFP_KERNEL);
if (!ep93xxbl)
return -ENOMEM;
+ res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -ENXIO;
+
/*
- * This register is located in the range already ioremap'ed by
- * the framebuffer driver. A MFD driver seems a bit of overkill
- * to handle this so use the static I/O mapping; this address
- * is already virtual.
+ * FIXME - We don't do a request_mem_region here because we are
+ * sharing the register space with the framebuffer driver (see
+ * drivers/video/ep93xx-fb.c) and doing so will cause the second
+ * loaded driver to return -EBUSY.
*
* NOTE: No locking is required; the framebuffer does not touch
* this register.
*/
- ep93xxbl->mmio = EP93XX_RASTER_BRIGHTNESS;
+ ep93xxbl->mmio = devm_ioremap(&dev->dev, res->start,
+ resource_size(res));
+ if (!ep93xxbl->mmio)
+ return -ENXIO;
memset(&props, 0, sizeof(struct backlight_properties));
props.type = BACKLIGHT_RAW;
diff --git a/drivers/video/ep93xx-fb.c b/drivers/video/ep93xx-fb.c
index 2e830ec5..f8babbe 100644
--- a/drivers/video/ep93xx-fb.c
+++ b/drivers/video/ep93xx-fb.c
@@ -519,12 +519,15 @@
goto failed;
}
- res = request_mem_region(res->start, resource_size(res), pdev->name);
- if (!res) {
- err = -EBUSY;
- goto failed;
- }
-
+ /*
+ * FIXME - We don't do a request_mem_region here because we are
+ * sharing the register space with the backlight driver (see
+ * drivers/video/backlight/ep93xx_bl.c) and doing so will cause
+ * the second loaded driver to return -EBUSY.
+ *
+ * NOTE: No locking is required; the backlight does not touch
+ * any of the framebuffer registers.
+ */
fbi->res = res;
fbi->mmio_base = ioremap(res->start, resource_size(res));
if (!fbi->mmio_base) {
@@ -586,8 +589,6 @@
clk_put(fbi->clk);
if (fbi->mmio_base)
iounmap(fbi->mmio_base);
- if (fbi->res)
- release_mem_region(fbi->res->start, resource_size(fbi->res));
ep93xxfb_dealloc_videomem(info);
if (&info->cmap)
fb_dealloc_cmap(&info->cmap);
@@ -608,7 +609,6 @@
clk_disable(fbi->clk);
clk_put(fbi->clk);
iounmap(fbi->mmio_base);
- release_mem_region(fbi->res->start, resource_size(fbi->res));
ep93xxfb_dealloc_videomem(info);
fb_dealloc_cmap(&info->cmap);