diff options
| -rw-r--r-- | drivers/video/fbdev/tdfxfb.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/drivers/video/fbdev/tdfxfb.c b/drivers/video/fbdev/tdfxfb.c index 9a06cef75699..fad365c00628 100644 --- a/drivers/video/fbdev/tdfxfb.c +++ b/drivers/video/fbdev/tdfxfb.c @@ -71,6 +71,7 @@ #include <linux/string.h> #include <linux/mm.h> #include <linux/slab.h> +#include <linux/vmalloc.h> #include <linux/fb.h> #include <linux/init.h> #include <linux/pci.h> @@ -336,6 +337,83 @@ static u32 do_calc_pll(int freq, int *freq_out) return (n << 8) | (m << 2) | k; } +/* + * Convert a pllctrl register value back to a frequency in kHz. + * Formula from 3dfx documentation. + */ +static u32 tdfx_pll_to_khz(u32 pll) +{ + return (14318 * (((pll >> 8) & 0xff) + 2) / + (((pll >> 2) & 0x3f) + 2)) >> (pll & 3); +} + +/* Layout of the "OEM config" table in voodoo 3 BIOS */ +struct tdfx_bios_cfg { + __le32 pciinit0; /* 0x00 */ + __le32 miscinit0; /* 0x04 */ + __le32 miscinit1; /* 0x08 */ + __le32 draminit0; /* 0x0c */ + __le32 draminit1; /* 0x10 */ + __le32 agpinit0; /* 0x14 */ + __le32 pllctrl1; /* 0x18 - memory PLL */ + __le32 pllctrl2; /* 0x1c - graphics PLL */ + __le32 sgrammode; /* 0x20 - SGRAM/SDRAM mode register data */ +} __packed; + +#define TDFX_ROM_CFG_PTR 0x50 + +static bool tdfxfb_get_bios_cfg(struct pci_dev *pdev, + struct tdfx_bios_cfg *cfg) +{ + u16 romcfg, oemcfg; + void __iomem *rom; + size_t romsize; + u8 *image; + u32 khz; + + /* This only works for the Voodoo 3 for now */ + if (pdev->device != PCI_DEVICE_ID_3DFX_VOODOO3) + return false; + + rom = pci_map_rom(pdev, &romsize); + if (!rom || !romsize) + return false; + + image = vmalloc(romsize); + if (!image) { + pci_unmap_rom(pdev, rom); + return false; + } + memcpy_fromio(image, rom, romsize); + pci_unmap_rom(pdev, rom); + + /* ROM[0x50] -> ROM config table -> OEM config table */ + if (TDFX_ROM_CFG_PTR + 2 > romsize) + goto out; + romcfg = image[TDFX_ROM_CFG_PTR] | image[TDFX_ROM_CFG_PTR + 1] << 8; + if (romcfg == 0xffff || romcfg + 2 > romsize) + goto out; + oemcfg = image[romcfg] | image[romcfg + 1] << 8; + if (oemcfg == 0xffff || oemcfg + sizeof(*cfg) > romsize) + goto out; + memcpy(cfg, image + oemcfg, sizeof(*cfg)); + vfree(image); + + /* + * Make sure we didn't read garbage from the BIOS and will + * end up setting a frequency that explodes someone's expensive + * card. + */ + khz = tdfx_pll_to_khz(le32_to_cpu(cfg->pllctrl1)); + if (khz < 40000 || khz > 250000 || !le32_to_cpu(cfg->draminit0)) + return false; + return true; + +out: + vfree(image); + return false; +} + static void do_write_regs(struct fb_info *info, struct banshee_reg *reg) { struct tdfx_par *par = info->par; |