From: Ryan Mallon Date: Sun, 22 Jan 2012 09:31:32 +0000 (+1100) Subject: ep93xx: Use ioremap for backlight driver X-Git-Tag: firefly_0821_release~3680^2~3252^2^2~7 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=0fd1958050e92c859152e775e548284582335d25;p=firefly-linux-kernel-4.4.55.git 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 Suggested-by: Arnd Bergmann Cc: Mika Westerberg Cc: Richard Purdie Cc: Florian Tobias Schandinat Acked-by: Arnd Bergmann Acked-by: H Hartley Sweeten --- diff --git a/arch/arm/mach-ep93xx/core.c b/arch/arm/mach-ep93xx/core.c index b5c1dae8327f..c73e299b08a5 100644 --- a/arch/arm/mach-ep93xx/core.c +++ b/arch/arm/mach-ep93xx/core.c @@ -682,9 +682,19 @@ static struct platform_device ep93xx_fb_device = { .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 b62b8b9063b5..08214e1f0958 100644 --- a/drivers/video/backlight/ep93xx_bl.c +++ b/drivers/video/backlight/ep93xx_bl.c @@ -17,11 +17,6 @@ #include #include -#include - -#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 @@ static int ep93xxbl_set(struct backlight_device *bl, int brightness) { 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 @@ static int __init ep93xxbl_probe(struct platform_device *dev) 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 2e830ec52a5a..f8babbeee275 100644 --- a/drivers/video/ep93xx-fb.c +++ b/drivers/video/ep93xx-fb.c @@ -519,12 +519,15 @@ static int __devinit ep93xxfb_probe(struct platform_device *pdev) 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 @@ failed: 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 @@ static int __devexit ep93xxfb_remove(struct platform_device *pdev) 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);