path: root/drivers/video/s3c-fb.c

/* linux/drivers/video/s3c-fb.c
 *
 * Copyright 2008 Openmoko Inc.
 * Copyright 2008-2010 Simtec Electronics
 *      Ben Dooks <ben@simtec.co.uk>
 *      http://armlinux.simtec.co.uk/
 *
 * Samsung SoC Framebuffer driver
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
*/

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/clk.h>
#include <linux/fb.h>
#include <linux/io.h>

#include <mach/map.h>
#include <mach/regs-fb.h>
#include <plat/fb.h>

/* This driver will export a number of framebuffer interfaces depending
 * on the configuration passed in via the platform data. Each fb instance
 * maps to a hardware window. Currently there is no support for runtime
 * setting of the alpha-blending functions that each window has, so only
 * window 0 is actually useful.
 *
 * Window 0 is treated specially, it is used for the basis of the LCD
 * output timings and as the control for the output power-down state.
*/

/* note, the previous use of <mach/regs-fb.h> to get platform specific data
 * has been replaced by using the platform device name to pick the correct
 * configuration data for the system.
*/

#ifdef CONFIG_FB_S3C_DEBUG_REGWRITE
#undef writel
#define writel(v, r) do { \
	printk(KERN_DEBUG "%s: %08x => %p\n", __func__, (unsigned int)v, r); \
	__raw_writel(v, r); } while(0)
#endif /* FB_S3C_DEBUG_REGWRITE */

struct s3c_fb;

#define VALID_BPP(x) (1 << ((x) - 1))

/**
 * struct s3c_fb_variant - fb variant information
 * @nr_windows: The number of windows.
 * @palette: Address of palette memory, or 0 if none.
 */
struct s3c_fb_variant {
	unsigned short	nr_windows;
	unsigned short	palette[S3C_FB_MAX_WIN];
};

/**
 * struct s3c_fb_win_variant
 * @has_osd_c: Set if has OSD C register.
 * @has_osd_d: Set if has OSD D register.
 * @palette_sz: Size of palette in entries.
 * @palette_16bpp: Set if palette is 16bits wide.
 * @valid_bpp: 1 bit per BPP setting to show valid bits-per-pixel.
 *
 * valid_bpp bit x is set if (x+1)BPP is supported.
 */
struct s3c_fb_win_variant {
	unsigned int	has_osd_c:1;
	unsigned int	has_osd_d:1;
	unsigned int	palette_16bpp:1;
	unsigned short	palette_sz;
	u32		valid_bpp;
};

/**
 * struct s3c_fb_driverdata - per-device type driver data for init time.
 * @variant: The variant information for this driver.
 * @win: The window information for each window.
 */
struct s3c_fb_driverdata {
	struct s3c_fb_variant	variant;
	struct s3c_fb_win_variant *win[S3C_FB_MAX_WIN];
};

/**
 * struct s3c_fb_win - per window private data for each framebuffer.
 * @windata: The platform data supplied for the window configuration.
 * @parent: The hardware that this window is part of.
 * @fbinfo: Pointer pack to the framebuffer info for this window.
 * @varint: The variant information for this window.
 * @palette_buffer: Buffer/cache to hold palette entries.
 * @pseudo_palette: For use in TRUECOLOUR modes for entries 0..15/
 * @index: The window number of this window.
 * @palette: The bitfields for changing r/g/b into a hardware palette entry.
 */
struct s3c_fb_win {
	struct s3c_fb_pd_win	*windata;
	struct s3c_fb		*parent;
	struct fb_info		*fbinfo;
	struct s3c_fb_palette	 palette;
	struct s3c_fb_win_variant variant;

	u32			*palette_buffer;
	u32			 pseudo_palette[16];
	unsigned int		 index;
};

/**
 * struct s3c_fb - overall hardware state of the hardware
 * @dev: The device that we bound to, for printing, etc.
 * @regs_res: The resource we claimed for the IO registers.
 * @bus_clk: The clk (hclk) feeding our interface and possibly pixclk.
 * @regs: The mapped hardware registers.
 * @variant: Variant information for this hardware.
 * @enabled: A bitmask of enabled hardware windows.
 * @pdata: The platform configuration data passed with the device.
 * @windows: The hardware windows that have been claimed.
 */
struct s3c_fb {
	struct device		*dev;
	struct resource		*regs_res;
	struct clk		*bus_clk;
	void __iomem		*regs;
	struct s3c_fb_variant	 variant;

	unsigned char		 enabled;

	struct s3c_fb_platdata	*pdata;
	struct s3c_fb_win	*windows[S3C_FB_MAX_WIN];
};

/**
 * s3c_fb_validate_win_bpp - validate the bits-per-pixel for this mode.
 * @win: The device window.
 * @bpp: The bit depth.
 */
static bool s3c_fb_validate_win_bpp(struct s3c_fb_win *win, unsigned int bpp)
{
	return win->variant.valid_bpp & VALID_BPP(bpp);
}

/**
 * s3c_fb_check_var() - framebuffer layer request to verify a given mode.
 * @var: The screen information to verify.
 * @info: The framebuffer device.
 *
 * Framebuffer layer call to verify the given information and allow us to
 * update various information depending on the hardware capabilities.
 */
static int s3c_fb_check_var(struct fb_var_screeninfo *var,
			    struct fb_info *info)
{
	struct s3c_fb_win