// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Driver for Aeroflex Gaisler SVGACTRL framebuffer device.
*
* 2011 (c) Aeroflex Gaisler AB
*
* Full documentation of the core can be found here:
* https://www.gaisler.com/products/grlib/grip.pdf
*
* Contributors: Kristoffer Glembo <[email protected]>
*/
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/of.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/mm.h>
#include <linux/fb.h>
#include <linux/io.h>
struct grvga_regs {
u32 status; /* 0x00 */
u32 video_length; /* 0x04 */
u32 front_porch; /* 0x08 */
u32 sync_length; /* 0x0C */
u32 line_length; /* 0x10 */
u32 fb_pos; /* 0x14 */
u32 clk_vector[4]; /* 0x18 */
u32 clut; /* 0x20 */
};
struct grvga_par {
struct grvga_regs *regs;
u32 color_palette[16]; /* 16 entry pseudo palette used by fbcon in true color mode */
int clk_sel;
int fb_alloced; /* = 1 if framebuffer is allocated in main memory */
};
static const struct fb_videomode grvga_modedb[] = {
{
/* 640x480 @ 60 Hz */
NULL, 60, 640, 480, 40000, 48, 16, 39, 11, 96, 2,
0, FB_VMODE_NONINTERLACED
}, {
/* 800x600 @ 60 Hz */
NULL, 60, 800, 600, 25000, 88, 40, 23, 1, 128, 4,
0, FB_VMODE_NONINTERLACED
}, {
/* 800x600 @ 72 Hz */
NULL, 72, 800, 600, 20000, 64, 56, 23, 37, 120, 6,
0, FB_VMODE_NONINTERLACED
}, {
/* 1024x768 @ 60 Hz */
NULL, 60, 1024, 768, 15385, 160, 24, 29, 3, 136, 6,
0, FB_VMODE_NONINTERLACED
}
};
static const struct fb_fix_screeninfo grvga_fix = {
.id = "AG SVGACTRL",
.type = FB_TYPE_PACKED_PIXELS,
.visual = FB_VISUAL_PSEUDOCOLOR,
.xpanstep = 0,
.ypanstep = 1,
.ywrapstep = 0,
.accel = FB_ACCEL_NONE,
};
static int grvga_check_var(struct fb_var_screeninfo *var,
struct fb_info *info)
{
struct grvga_par *par = info->par;
int i;
if (!var->xres)
var->xres = 1;
if (!var->yres)
var->yres = 1;
if (var->bits_per_pixel <= 8)
var->bits_per_pixel = 8;
else if (var->bits_per_pixel <= 16)
var->bits_per_pixel = 16;
else if (var->bits_per_pixel <= 24)
var->bits_per_pixel = 24;
else if (var->bits_per_pixel <= 32)
var->bits_per_pixel = 32;
else
return -EINVAL;
var->xres_virtual = var->xres;
var->yres_virtual = 2*var->yres;
if (info->fix.smem_len) {
if ((var->yres_virtual*var->xres_virtual*var->bits_per_pixel/8) > info->fix.smem_len)
return -ENOMEM;
}
/* Which clocks that are available can be read out in these registers */
for (i = 0; i <= 3 ; i++) {
if (var->pixclock == par->regs->clk_vector[i])
break;
}
if (i <= 3)
par->clk_sel = i;
else
return -EINVAL;
switch (info->var.bits_per_pixel) {
case 8:
var->red = (struct fb_bitfield) {0, 8, 0}; /* offset, length, msb-right */
var->green = (struct fb_bitfield) {0, 8, 0};
var->blue = (struct fb_bitfield) {0, 8, 0};
var->transp = (struct fb_bitfield) {0, 0, 0};
break;
case 16:
var->red = (struct fb_bitfield) {11, 5, 0};
var->green = (struct fb_bitfield) {5, 6, 0};
var->blue = (struct fb_bitfield) {0, 5, 0};
var->transp = (struct fb_bitfield) {0, 0, 0};
break;
case 24:
case 32:
var->red = (struct fb_bitfield) {16, 8, 0};
var->green = (struct fb_bitfield) {8, 8, 0};
var->blue = (struct fb_bitfield) {0, 8, 0};
var->transp = (struct fb_bitfield) {24, 8, 0};
break;
default:
return -EINVAL;
}
return 0;
}
static int grvga_set_par(struct fb_info *info)
{
u32 func = 0;
struct grvga_par *par = info->par;
__raw_writel(((info->var.yres - 1) << 16) | (info->var.xres - 1),
&par->regs->video_length);
__raw_writel((info->var.lower_margin << 16) | (info->var.right_margin),
&par->regs->front_porch);
__raw_writel((info->var.vsync_len << 16) | (info->var.hsync_len),
&par->regs->sync_length);
__raw_writel(((info->var.yres + info->var.lower_margin + info->var.upper_margin + info->var.vsync_len - 1) << 16) |
(info->var.xres + info->var.right_margin + info->var.left_margin + info->var.hsync_len - 1),
&par->regs->line_length);
switch (info->var.bits_per_pixel) {
case 8:
info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
func = 1;
break;
case 16:
info->fix.visual = FB_VISUAL_TRUECOLOR;
func = 2;
break;
case 24:
case 32:
info->fix.visual = FB_VISUAL_TRUECOLOR;
func = 3;
break;
default:
return -EINVAL;
}
__raw_writel((par->clk_sel << 6) | (func << 4) | 1,
&par->regs->status);
info->fix.line_length = (info->var.xres_virtual*info->var.bits_per_pixel)/8;
return 0;
}
static int grvga_setcolreg(unsigned regno, unsigned red, unsigned green, unsigned blue, unsigned transp, struct fb_info *info)
{
struct grvga_par *par;
par = info->par;
if (regno >= 256) /* Size of CLUT */
return -EINVAL;
if (info->var.grayscale) {
/* grayscale = 0.30*R + 0.59*G + 0.11*B */
red = green = blue = (red * 77 + green * 151 + blue * 28) >> 8;
}
#define CNVT_TOHW(val, width) ((((val)<<(width))+0x7FFF-(val))>>16)
red = CNVT_TOHW(red, info->var.red.length);
green = CNVT_TOHW(green, info->var.green.length);
blue = CNVT_TOHW(blue, info->var.blue.length);
transp = CNVT_TOHW(transp, info->var.transp.length);
#undef CNVT_TOHW
/* In PSEUDOCOLOR we use the hardware CLUT */
if (info->fix.visual == FB_VISUAL_PSEUDOCOLOR)
__raw_writel((regno << 24) | (red << 16) | (green << 8) | blue,
&par->regs->clut);
/* Truecolor uses the pseudo palette */
else if (info->fix.visual == FB_VISUAL_TRUECOLOR) {
u32 v;
if (regno >= 16)
return -EINVAL;
v = (red << info->var.red.offset) |
(green << info->var.green.offset) |
(blue << info->var.blue.offset) |
(transp << info->var.transp.offset);
((u32 *) (info->pseudo_palette))[regno] = v;
}
return 0;
}
static int grvga_pan_display(struct fb_var_screeninfo *var,
struct fb_info *info)
{
struct grvga_par *par = info->par;
struct fb_fix_screeninfo *fix = &info->fix;
u32 base_addr;
if (var->xoffset != 0)
return -EINVAL;
base_addr = fix->smem_start + (var->yoffset * fix->line_length);
base_addr &= ~3UL;
/* Set framebuffer base address */
__raw_writel(base_addr,
&par->regs->fb_pos);
return 0;
}
static const struct fb_ops grvga_ops = {
.owner = THIS_MODULE,
FB_DEFAULT_IOMEM_OPS,
.fb_check_var = grvga_check_var,
.fb_set_par = grvga_set_par,
.fb_setcolreg = grvga_setcolreg,
.fb_pan_display = grvga_pan_display,
};
static int grvga_parse_custom(char *options,
struct fb_var_screeninfo *screendata)
{
char *this_opt;
int count = 0;
if (!options || !*options)
return -1;
while ((this_opt = strsep(&options, " ")) != NULL) {
if (!*this_opt)
continue;
switch (count) {
case 0:
screendata->pixclock = simple_strtoul(this_opt, NULL, 0);
count++;
break;
case 1:
screendata->xres = screendata->xres_virtual = simple_strtoul(this_opt, NULL, 0);
count++;
break;
case 2:
screendata->right_margin = simple_strtoul(this_opt, NULL, 0);
count++;
break;
case 3:
screendata->hsync_len = simple_strtoul(this_opt, NULL, 0);
count++;
break;
case 4:
screendata->left_margin = simple_strtoul(this_opt, NULL, 0);
count++;
break;
case 5:
screendata->yres = screendata->yres_virtual = simple_strtoul(this_opt, NULL, 0);
count++;
break;
case 6:
screendata->lower_margin = simple_strtoul(this_opt, NULL, 0);
count++;
break;
case 7:
screendata->vsync_len = simple_strtoul(this_opt, NULL, 0);
count++;
break;
case 8:
screendata->upper_margin = simple_strtoul(this_opt, NULL, 0);
count++;
break;
case 9:
screendata->bits_per_pixel = simple_strtoul(this_opt, NULL, 0);
count++;
break;
default:
return -1;
}
}
screendata->activate = FB_ACTIVATE_NOW;
screendata->vmode = FB_VMODE_NONINTERLACED;
return 0;
}
static int grvga_probe(struct platform_device *dev)
{
struct fb_info *info;
int retval = -ENOMEM;
unsigned long virtual_start;
unsigned long grvga_fix_addr = 0;
unsigned long physical_start = 0;
unsigned long grvga_mem_size = 0;
struct grvga_par *par = NULL;
char *options = NULL, *mode_opt = NULL;
info = framebuffer_alloc(sizeof(struct grvga_par), &dev->dev);
if (!info)
return -ENOMEM;
/* Expecting: "grvga: modestring, [addr:<framebuffer physical address>], [size:<framebuffer size>]
*
* If modestring is custom:<custom mode string> we parse the string which then contains all videoparameters
* If address is left out, we allocate memory,
* if size is left out we only allocate enough to support the given mode.
*/
if (fb_get_options("grvga", &options)) {
retval = -ENODEV;
goto free_fb;
}
if (!options || !*options)
options = "640x480-8@60";
while (1) {
char *this_opt = strsep(&options, ",");
if (!this_opt)
break;
if (!strncmp(this_opt, "custom", 6)) {
if (grvga_parse_custom(this_opt, &info->var) < 0) {
dev_err(&dev->dev, "Failed to parse custom mode (%s).\n", this_opt);
retval = -EINVAL;
goto free_fb;
}
} else if (!strncmp(this_opt, "addr", 4))
grvga_fix_addr = simple_strtoul(this_opt + 5, NULL, 16);
else if (!strncmp(this_opt, "size", 4))
grvga_mem_size = simple_strtoul(this_opt + 5, NULL, 0);
else
mode_opt = this_opt;
}
par = info->par;
info->fbops = &grvga_ops;
info->fix = grvga_fix;
info->pseudo_palette = par->color_palette;
info->flags = FBINFO_PARTIAL_PAN_OK | FBINFO_HWACCEL_YPAN;
info->fix.smem_len = grvga_mem_size;
if (!devm_request_mem_region(&dev->dev, dev->resource[0].start,
resource_size(&dev->resource[0]), "grlib-svgactrl regs")) {
dev_err(&dev->dev, "registers already mapped\n");
retval = -EBUSY;
goto free_fb;
}
par->regs = of_ioremap(&dev->resource[0], 0,
resource_size(&dev->resource[0]),
"grlib-svgactrl regs");
if (!par->regs) {
dev_err(&dev->dev, "failed to map registers\n");
retval = -ENOMEM;
goto free_fb;
}
retval = fb_alloc_cmap(&info->cmap, 256, 0);
if (retval < 0) {
dev_err(&dev->dev, "failed to allocate mem with fb_alloc_cmap\n");
retval = -ENOMEM;
goto unmap_regs;
}
if (mode_opt) {
retval = fb_find_mode(&info->var, info, mode_opt,
grvga_modedb, sizeof(grvga_modedb), &grvga_modedb[0], 8);
if (!retval || retval == 4) {
retval = -EINVAL;
goto dealloc_cmap;
}
}
if (!grvga_mem_size)
grvga_mem_size = info->var.xres_virtual * info->var.yres_virtual * info->var.bits_per_pixel/8;
if (grvga_fix_addr) {
/* Got framebuffer base address from argument list */
physical_start = grvga_fix_addr;
if (!devm_request_mem_region(&dev->dev, physical_start,
grvga_mem_size, dev->name)) {
dev_err(&dev->dev, "failed to request memory region\n");
retval = -ENOMEM;
goto dealloc_cmap;
}
virtual_start = (unsigned long) ioremap(physical_start, grvga_mem_size);
if (!virtual_start) {
dev_err(&dev->dev, "error mapping framebuffer memory\n");
retval = -ENOMEM;
goto dealloc_cmap;
}
} else { /* Allocate frambuffer memory */
unsigned long page;
virtual_start = (unsigned long) __get_free_pages(GFP_DMA,
get_order(grvga_mem_size));
if (!virtual_start) {
dev_err(&dev->dev,
"unable to allocate framebuffer memory (%lu bytes)\n",
grvga_mem_size);
retval = -ENOMEM;
goto dealloc_cmap;
}
physical_start = dma_map_single(&dev->dev, (void *)virtual_start, grvga_mem_size, DMA_TO_DEVICE);
/* Set page reserved so that mmap will work. This is necessary
* since we'll be remapping normal memory.
*/
for (page = virtual_start;
page < PAGE_ALIGN(virtual_start + grvga_mem_size);
page += PAGE_SIZE) {
SetPageReserved(virt_to_page(page));
}
par->fb_alloced = 1;
}
memset((unsigned long *) virtual_start, 0, grvga_mem_size);
info->screen_base = (char __iomem *) virtual_start;
info->fix.smem_start = physical_start;
info->fix.smem_len = grvga_mem_size;
dev_set_drvdata(&dev->dev, info);
dev_info(&dev->dev,
"Aeroflex Gaisler framebuffer device (fb%d), %dx%d-%d, using %luK of video memory @ %p\n",
info->node, info->var.xres, info->var.yres, info->var.bits_per_pixel,
grvga_mem_size >> 10, info->screen_base);
retval = register_framebuffer(info);
if (retval < 0) {
dev_err(&dev->dev, "failed to register framebuffer\n");
goto free_mem;
}
__raw_writel(physical_start, &par->regs->fb_pos);
__raw_writel(__raw_readl(&par->regs->status) | 1, /* Enable framebuffer */
&par->regs->status);
return 0;
free_mem:
if (grvga_fix_addr)
iounmap((void *)virtual_start);
else
kfree((void *)virtual_start);
dealloc_cmap:
fb_dealloc_cmap(&info->cmap);
unmap_regs:
of_iounmap(&dev->resource[0], par->regs,
resource_size(&dev->resource[0]));
free_fb:
framebuffer_release(info);
return retval;
}
static void grvga_remove(struct platform_device *device)
{
struct fb_info *info = dev_get_drvdata(&device->dev);
struct grvga_par *par;
if (info) {
par = info->par;
unregister_framebuffer(info);
fb_dealloc_cmap(&info->cmap);
of_iounmap(&device->resource[0], par->regs,
resource_size(&device->resource[0]));
if (!par->fb_alloced)
iounmap(info->screen_base);
else
kfree((void *)info->screen_base);
framebuffer_release(info);
}
}
static struct of_device_id svgactrl_of_match[] = {
{
.name = "GAISLER_SVGACTRL",
},
{
.name = "01_063",
},
{},
};
MODULE_DEVICE_TABLE(of, svgactrl_of_match);
static struct platform_driver grvga_driver = {
.driver = {
.name = "grlib-svgactrl",
.of_match_table = svgactrl_of_match,
},
.probe = grvga_probe,
.remove_new = grvga_remove,
};
module_platform_driver(grvga_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Aeroflex Gaisler");
MODULE_DESCRIPTION("Aeroflex Gaisler framebuffer device driver");
Codebase Browser
linux