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// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/drivers/video/ep93xx-fb.c
*
* Framebuffer support for the EP93xx series.
*
* Copyright (C) 2007 Bluewater Systems Ltd
* Author: Ryan Mallon
*
* Copyright (c) 2009 H Hartley Sweeten <hsweeten@visionengravers.com>
*
* Based on the Cirrus Logic ep93xxfb driver, and various other ep93xxfb
* drivers.
*/
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/fb.h>
#include <linux/io.h>
#include <linux/platform_data/video-ep93xx.h>
/* Vertical Frame Timing Registers */
#define EP93XXFB_VLINES_TOTAL 0x0000 /* SW locked */
#define EP93XXFB_VSYNC 0x0004 /* SW locked */
#define EP93XXFB_VACTIVE 0x0008 /* SW locked */
#define EP93XXFB_VBLANK 0x0228 /* SW locked */
#define EP93XXFB_VCLK 0x000c /* SW locked */
/* Horizontal Frame Timing Registers */
#define EP93XXFB_HCLKS_TOTAL 0x0010 /* SW locked */
#define EP93XXFB_HSYNC 0x0014 /* SW locked */
#define EP93XXFB_HACTIVE 0x0018 /* SW locked */
#define EP93XXFB_HBLANK 0x022c /* SW locked */
#define EP93XXFB_HCLK 0x001c /* SW locked */
/* Frame Buffer Memory Configuration Registers */
#define EP93XXFB_SCREEN_PAGE 0x0028
#define EP93XXFB_SCREEN_HPAGE 0x002c
#define EP93XXFB_SCREEN_LINES 0x0030
#define EP93XXFB_LINE_LENGTH 0x0034
#define EP93XXFB_VLINE_STEP 0x0038
#define EP93XXFB_LINE_CARRY 0x003c /* SW locked */
#define EP93XXFB_EOL_OFFSET 0x0230
/* Other Video Registers */
#define EP93XXFB_BRIGHTNESS 0x0020
#define EP93XXFB_ATTRIBS 0x0024 /* SW locked */
#define EP93XXFB_SWLOCK 0x007c /* SW locked */
#define EP93XXFB_AC_RATE 0x0214
#define EP93XXFB_FIFO_LEVEL 0x0234
#define EP93XXFB_PIXELMODE 0x0054
#define EP93XXFB_PIXELMODE_32BPP (0x7 << 0)
#define EP93XXFB_PIXELMODE_24BPP (0x6 << 0)
#define EP93XXFB_PIXELMODE_16BPP (0x4 << 0)
#define EP93XXFB_PIXELMODE_8BPP (0x2 << 0)
#define EP93XXFB_PIXELMODE_SHIFT_1P_24B (0x0 << 3)
#define EP93XXFB_PIXELMODE_SHIFT_1P_18B (0x1 << 3)
#define EP93XXFB_PIXELMODE_COLOR_LUT (0x0 << 10)
#define EP93XXFB_PIXELMODE_COLOR_888 (0x4 << 10)
#define EP93XXFB_PIXELMODE_COLOR_555 (0x5 << 10)
#define EP93XXFB_PARL_IF_OUT 0x0058
#define EP93XXFB_PARL_IF_IN 0x005c
/* Blink Control Registers */
#define EP93XXFB_BLINK_RATE 0x0040
#define EP93XXFB_BLINK_MASK 0x0044
#define EP93XXFB_BLINK_PATTRN 0x0048
#define EP93XXFB_PATTRN_MASK 0x004c
#define EP93XXFB_BKGRND_OFFSET 0x0050
/* Hardware Cursor Registers */
#define EP93XXFB_CURSOR_ADR_START 0x0060
#define EP93XXFB_CURSOR_ADR_RESET 0x0064
#define EP93XXFB_CURSOR_SIZE 0x0068
#define EP93XXFB_CURSOR_COLOR1 0x006c
#define EP93XXFB_CURSOR_COLOR2 0x0070
#define EP93XXFB_CURSOR_BLINK_COLOR1 0x021c
#define EP93XXFB_CURSOR_BLINK_COLOR2 0x0220
#define EP93XXFB_CURSOR_XY_LOC 0x0074
#define EP93XXFB_CURSOR_DSCAN_HY_LOC 0x0078
#define EP93XXFB_CURSOR_BLINK_RATE_CTRL 0x0224
/* LUT Registers */
#define EP93XXFB_GRY_SCL_LUTR 0x0080
#define EP93XXFB_GRY_SCL_LUTG 0x0280
#define EP93XXFB_GRY_SCL_LUTB 0x0300
#define EP93XXFB_LUT_SW_CONTROL 0x0218
#define EP93XXFB_LUT_SW_CONTROL_SWTCH (1 << 0)
#define EP93XXFB_LUT_SW_CONTROL_SSTAT (1 << 1)
#define EP93XXFB_COLOR_LUT 0x0400
/* Video Signature Registers */
#define EP93XXFB_VID_SIG_RSLT_VAL 0x0200
#define EP93XXFB_VID_SIG_CTRL 0x0204
#define EP93XXFB_VSIG 0x0208
#define EP93XXFB_HSIG 0x020c
#define EP93XXFB_SIG_CLR_STR 0x0210
/* Minimum / Maximum resolutions supported */
#define EP93XXFB_MIN_XRES 64
#define EP93XXFB_MIN_YRES 64
#define EP93XXFB_MAX_XRES 1024
#define EP93XXFB_MAX_YRES 768
struct ep93xx_fbi {
struct ep93xxfb_mach_info *mach_info;
struct clk *clk;
struct resource *res;
void __iomem *mmio_base;
unsigned int pseudo_palette[256];
};
static int check_screenpage_bug = 1;
module_param(check_screenpage_bug, int, 0644);
MODULE_PARM_DESC(check_screenpage_bug,
"Check for bit 27 screen page bug. Default = 1");
static inline unsigned int ep93xxfb_readl(struct ep93xx_fbi *fbi,
unsigned int off)
{
return __raw_readl(fbi->mmio_base + off);
}
static inline void ep93xxfb_writel(struct ep93xx_fbi *fbi,
unsigned int val, unsigned int off)
{
__raw_writel(val, fbi->mmio_base + off);
}
/*
* Write to one of the locked raster registers.
*/
static inline void ep93xxfb_out_locked(struct ep93xx_fbi *fbi,
unsigned int val, unsigned int reg)
{
/*
* We don't need a lock or delay here since the raster register
* block will remain unlocked until the next access.
*/
ep93xxfb_writel(fbi, 0xaa, EP93XXFB_SWLOCK);
ep93xxfb_writel(fbi, val, reg);
}
static void ep93xxfb_set_video_attribs(struct fb_info *info)
{
struct ep93xx_fbi *fbi = info->par;
unsigned int attribs;
attribs = EP93XXFB_ENABLE;
attribs |= fbi->mach_info->flags;
ep93xxfb_out_locked(fbi, attribs, EP93XXFB_ATTRIBS);
}
static int ep93xxfb_set_pixelmode(struct fb_info *info)
{
struct ep93xx_fbi *fbi = info->par;
unsigned int val;
info->var.transp.offset = 0;
info->var.transp.length = 0;
switch (info->var.bits_per_pixel) {
case 8:
val = EP93XXFB_PIXELMODE_8BPP | EP93XXFB_PIXELMODE_COLOR_LUT |
EP93XXFB_PIXELMODE_SHIFT_1P_18B;
info->var.red.offset = 0;
info->var.red.length = 8;
info->var.green.offset = 0;
info->var.green.length = 8;
info->var.blue.offset = 0;
info->var.blue.length = 8;
info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
break;
case 16:
val = EP93XXFB_PIXELMODE_16BPP | EP93XXFB_PIXELMODE_COLOR_555 |
EP93XXFB_PIXELMODE_SHIFT_1P_18B;
info->var.red.offset = 11;
info->var.red.length = 5;
info->var.green.offset = 5;
info->var.green.length = 6;
info->var.blue.offset = 0;
info->var.blue.length = 5;
info->fix.visual = FB_VISUAL_TRUECOLOR;
break;
case 24:
val = EP93XXFB_PIXELMODE_24BPP | EP93XXFB_PIXELMODE_COLOR_888 |
EP93XXFB_PIXELMODE_SHIFT_1P_24B;
info->var.red.offset = 16;
info->var.red.length = 8;
info->var.green.offset = 8;
info->var.green.length = 8;
info->var.blue.offset = 0;
info->var.blue.length = 8;
info->fix.visual = FB_VISUAL_TRUECOLOR;
break;
case 32:
val = EP93XXFB_PIXELMODE_32BPP | EP93XXFB_PIXELMODE_COLOR_888 |
EP93XXFB_PIXELMODE_SHIFT_1P_24B;
info->var.red.offset = 16;
info->var.red.length = 8;
info->var.green.offset = 8;
info->var.green.length = 8;
info->var.blue.offset = 0;
info->var.blue.length = 8;
info->fix.visual = FB_VISUAL_TRUECOLOR;
break;
default:
return -EINVAL;
}
ep93xxfb_writel(fbi, val, EP93XXFB_PIXELMODE);
return 0;
}
static void ep93xxfb_set_timing(struct fb_info *info)
{
struct ep93xx_fbi *fbi = info->par;
unsigned int vlines_total, hclks_total, start, stop;
vlines_total = info->var.yres + info->var.upper_margin +
info->var.lower_margin + info->var.vsync_len - 1;
hclks_total = info->var.xres + info->var.left_margin +
info->var.right_margin + info->var.hsync_len - 1;
ep93xxfb_out_locked(fbi, vlines_total, EP93XXFB_VLINES_TOTAL);
ep93xxfb_out_locked(fbi, hclks_total, EP93XXFB_HCLKS_TOTAL);
start = vlines_total;
stop = vlines_total - info->var.vsync_len;
ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_VSYNC);
start = vlines_total - info->var.vsync_len - info->var.upper_margin;
stop = info->var.lower_margin - 1;
ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_VBLANK);
ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_VACTIVE);
start = vlines_total;
stop = vlines_total + 1;
ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_VCLK);
start = hclks_total;
stop = hclks_total - info->var.hsync_len;
ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_HSYNC);
start = hclks_total - info->var.hsync_len - info->var.left_margin;
stop = info->var.right_margin - 1;
ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_HBLANK);
ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_HACTIVE);
start = hclks_total;
stop = hclks_total;
ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_HCLK);
ep93xxfb_out_locked(fbi, 0x0, EP93XXFB_LINE_CARRY);
}
static int ep93xxfb_set_par(struct fb_info *info)
{
struct ep93xx_fbi *fbi = info->par;
clk_set_rate(fbi->clk, 1000 * PICOS2KHZ(info->var.pixclock));
ep93xxfb_set_timing(info);
info->fix.line_length = info->var.xres_virtual *
info->var.bits_per_pixel / 8;
ep93xxfb_writel(fbi, info->fix.smem_start, EP93XXFB_SCREEN_PAGE);
ep93xxfb_writel(fbi, info->var.yres - 1, EP93XXFB_SCREEN_LINES);
ep93xxfb_writel(fbi, ((info->var.xres * info->var.bits_per_pixel)
/ 32) - 1, EP93XXFB_LINE_LENGTH);
ep93xxfb_writel(fbi, info->fix.line_length / 4, EP93XXFB_VLINE_STEP);
ep93xxfb_set_video_attribs(info);
return 0;
}
static int ep93xxfb_check_var(struct fb_var_screeninfo *var,
struct fb_info *info)
{
int err;
err = ep93xxfb_set_pixelmode(info);
if (err)
return err;
var->xres = max_t(unsigned int, var->xres, EP93XXFB_MIN_XRES);
var->xres = min_t(unsigned int, var->xres, EP93XXFB_MAX_XRES);
var->xres_virtual = max(var->xres_virtual, var->xres);
var->yres = max_t(unsigned int, var->yres, EP93XXFB_MIN_YRES);
var->yres = min_t(unsigned int, var->yres, EP93XXFB_MAX_YRES);
var->yres_virtual = max(var->yres_virtual, var->yres);
return 0;
}
static int ep93xxfb_mmap(struct fb_info *info, struct vm_area_struct *vma)
{
unsigned int offset = vma->vm_pgoff << PAGE_SHIFT;
if (offset < info->fix.smem_len) {
return dma_mmap_wc(info->dev, vma, info->screen_base,
info->fix.smem_start, info->fix.smem_len);
}
return -EINVAL;
}
static int ep93xxfb_blank(int blank_mode, struct fb_info *info)
{
struct ep93xx_fbi *fbi = info->par;
unsigned int attribs = ep93xxfb_readl(fbi, EP93XXFB_ATTRIBS);
if (blank_mode) {
if (fbi->mach_info->blank)
fbi->mach_info->blank(blank_mode, info);
ep93xxfb_out_locked(fbi, attribs & ~EP93XXFB_ENABLE,
EP93XXFB_ATTRIBS);
clk_disable(fbi->clk);
} else {
clk_enable(fbi->clk);
ep93xxfb_out_locked(fbi, attribs | EP93XXFB_ENABLE,
EP93XXFB_ATTRIBS);
if (fbi->mach_info->blank)
fbi->mach_info->blank(blank_mode, info);
}
return 0;
}
static inline int ep93xxfb_convert_color(int val, int width)
{
return ((val << width) + 0x7fff - val) >> 16;
}
static int ep93xxfb_setcolreg(unsigned int regno, unsigned int red,
unsigned int green, unsigned int blue,
unsigned int transp, struct fb_info *info)
{
struct ep93xx_fbi *fbi = info->par;
unsigned int *pal = info->pseudo_palette;
unsigned int ctrl, i, rgb, lut_current, lut_stat;
switch (info->fix.visual) {
case FB_VISUAL_PSEUDOCOLOR:
if (regno > 255)
return 1;
rgb = ((red & 0xff00) << 8) | (green & 0xff00) |
((blue & 0xff00) >> 8);
pal[regno] = rgb;
ep93xxfb_writel(fbi, rgb, (EP93XXFB_COLOR_LUT + (regno << 2)));
ctrl = ep93xxfb_readl(fbi, EP93XXFB_LUT_SW_CONTROL);
lut_stat = !!(ctrl & EP93XXFB_LUT_SW_CONTROL_SSTAT);
lut_current = !!(ctrl & EP93XXFB_LUT_SW_CONTROL_SWTCH);
if (lut_stat == lut_current) {
for (i = 0; i < 256; i++) {
ep93xxfb_writel(fbi, pal[i],
EP93XXFB_COLOR_LUT + (i << 2));
}
ep93xxfb_writel(fbi,
ctrl ^ EP93XXFB_LUT_SW_CONTROL_SWTCH,
EP93XXFB_LUT_SW_CONTROL);
}
break;
case FB_VISUAL_TRUECOLOR:
if (regno > 16)
return 1;
red = ep93xxfb_convert_color(red, info->var.red.length);
green = ep93xxfb_convert_color(green, info->var.green.length);
blue = ep93xxfb_convert_color(blue, info->var.blue.length);
transp = ep93xxfb_convert_color(transp,
info->var.transp.length);
pal[regno] = (red << info->var.red.offset) |
(green << info->var.green.offset) |
(blue << info->var.blue.offset) |
(transp << info->var.transp.offset);
break;
default:
return 1;
}
return 0;
}
static const struct fb_ops ep93xxfb_ops = {
.owner = THIS_MODULE,
.fb_check_var = ep93xxfb_check_var,
.fb_set_par = ep93xxfb_set_par,
.fb_blank = ep93xxfb_blank,
.fb_fillrect = cfb_fillrect,
.fb_copyarea = cfb_copyarea,
.fb_imageblit = cfb_imageblit,
.fb_setcolreg = ep93xxfb_setcolreg,
.fb_mmap = ep93xxfb_mmap,
};
static int ep93xxfb_alloc_videomem(struct fb_info *info)
{
char __iomem *virt_addr;
dma_addr_t phys_addr;
unsigned int fb_size;
/* Maximum 16bpp -> used memory is maximum x*y*2 bytes */
fb_size = EP93XXFB_MAX_XRES * EP93XXFB_MAX_YRES * 2;
virt_addr = dma_alloc_wc(info->dev, fb_size, &phys_addr, GFP_KERNEL);
if (!virt_addr)
return -ENOMEM;
/*
* There is a bug in the ep93xx framebuffer which causes problems
* if bit 27 of the physical address is set.
* See: http://marc.info/?l=linux-arm-kernel&m=110061245502000&w=2
* There does not seem to be any official errata for this, but I
* have confirmed the problem exists on my hardware (ep9315) at
* least.
*/
if (check_screenpage_bug && phys_addr & (1 << 27)) {
dev_err(info->dev, "ep93xx framebuffer bug. phys addr (0x%x) "
"has bit 27 set: cannot init framebuffer\n",
phys_addr);
dma_free_coherent(info->dev, fb_size, virt_addr, phys_addr);
return -ENOMEM;
}
info->fix.smem_start = phys_addr;
info->fix.smem_len = fb_size;
info->screen_base = virt_addr;
return 0;
}
static void ep93xxfb_dealloc_videomem(struct fb_info *info)
{
if (info->screen_base)
dma_free_coherent(info->dev, info->fix.smem_len,
info->screen_base, info->fix.smem_start);
}
static int ep93xxfb_probe(struct platform_device *pdev)
{
struct ep93xxfb_mach_info *mach_info = dev_get_platdata(&pdev->dev);
struct fb_info *info;
struct ep93xx_fbi *fbi;
struct resource *res;
char *video_mode;
int err;
if (!mach_info)
return -EINVAL;
info = framebuffer_alloc(sizeof(struct ep93xx_fbi), &pdev->dev);
if (!info)
return -ENOMEM;
info->dev = &pdev->dev;
platform_set_drvdata(pdev, info);
fbi = info->par;
fbi->mach_info = mach_info;
err = fb_alloc_cmap(&info->cmap, 256, 0);
if (err)
goto failed_cmap;
err = ep93xxfb_alloc_videomem(info);
if (err)
goto failed_videomem;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
err = -ENXIO;
goto failed_resource;
}
/*
* 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 = devm_ioremap(&pdev->dev, res->start,
resource_size(res));
if (!fbi->mmio_base) {
err = -ENXIO;
goto failed_resource;
}
strcpy(info->fix.id, pdev->name);
info->fbops = &ep93xxfb_ops;
info->fix.type = FB_TYPE_PACKED_PIXELS;
info->fix.accel = FB_ACCEL_NONE;
info->var.activate = FB_ACTIVATE_NOW;
info->var.vmode = FB_VMODE_NONINTERLACED;
info->flags = FBINFO_DEFAULT;
info->node = -1;
info->state = FBINFO_STATE_RUNNING;
info->pseudo_palette = &fbi->pseudo_palette;
fb_get_options("ep93xx-fb", &video_mode);
err = fb_find_mode(&info->var, info, video_mode,
NULL, 0, NULL, 16);
if (err == 0) {
dev_err(info->dev, "No suitable video mode found\n");
err = -EINVAL;
goto failed_resource;
}
if (mach_info->setup) {
err = mach_info->setup(pdev);
if (err)
goto failed_resource;
}
err = ep93xxfb_check_var(&info->var, info);
if (err)
goto failed_check;
fbi->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(fbi->clk)) {
err = PTR_ERR(fbi->clk);
fbi->clk = NULL;
goto failed_check;
}
ep93xxfb_set_par(info);
clk_enable(fbi->clk);
err = register_framebuffer(info);
if (err)
goto failed_check;
dev_info(info->dev, "registered. Mode = %dx%d-%d\n",
info->var.xres, info->var.yres, info->var.bits_per_pixel);
return 0;
failed_check:
if (fbi->mach_info->teardown)
fbi->mach_info->teardown(pdev);
failed_resource:
ep93xxfb_dealloc_videomem(info);
failed_videomem:
fb_dealloc_cmap(&info->cmap);
failed_cmap:
kfree(info);
return err;
}
static int ep93xxfb_remove(struct platform_device *pdev)
{
struct fb_info *info = platform_get_drvdata(pdev);
struct ep93xx_fbi *fbi = info->par;
unregister_framebuffer(info);
clk_disable(fbi->clk);
ep93xxfb_dealloc_videomem(info);
fb_dealloc_cmap(&info->cmap);
if (fbi->mach_info->teardown)
fbi->mach_info->teardown(pdev);
kfree(info);
return 0;
}
static struct platform_driver ep93xxfb_driver = {
.probe = ep93xxfb_probe,
.remove = ep93xxfb_remove,
.driver = {
.name = "ep93xx-fb",
},
};
module_platform_driver(ep93xxfb_driver);
MODULE_DESCRIPTION("EP93XX Framebuffer Driver");
MODULE_ALIAS("platform:ep93xx-fb");
MODULE_AUTHOR("Ryan Mallon, "
"H Hartley Sweeten <hsweeten@visionengravers.com");
MODULE_LICENSE("GPL");