diff options
Diffstat (limited to 'drivers/video/screen_info_generic.c')
| -rw-r--r-- | drivers/video/screen_info_generic.c | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/drivers/video/screen_info_generic.c b/drivers/video/screen_info_generic.c new file mode 100644 index 000000000000..900e9386eceb --- /dev/null +++ b/drivers/video/screen_info_generic.c @@ -0,0 +1,182 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/export.h> +#include <linux/ioport.h> +#include <linux/screen_info.h> +#include <linux/string.h> + +static void resource_init_named(struct resource *r, + resource_size_t start, resource_size_t size, + const char *name, unsigned int flags) +{ + memset(r, 0, sizeof(*r)); + + r->start = start; + r->end = start + size - 1; + r->name = name; + r->flags = flags; +} + +static void resource_init_io_named(struct resource *r, + resource_size_t start, resource_size_t size, + const char *name) +{ + resource_init_named(r, start, size, name, IORESOURCE_IO); +} + +static void resource_init_mem_named(struct resource *r, + resource_size_t start, resource_size_t size, + const char *name) +{ + resource_init_named(r, start, size, name, IORESOURCE_MEM); +} + +static inline bool __screen_info_has_ega_gfx(unsigned int mode) +{ + switch (mode) { + case 0x0d: /* 320x200-4 */ + case 0x0e: /* 640x200-4 */ + case 0x0f: /* 640x350-1 */ + case 0x10: /* 640x350-4 */ + return true; + default: + return false; + } +} + +static inline bool __screen_info_has_vga_gfx(unsigned int mode) +{ + switch (mode) { + case 0x10: /* 640x480-1 */ + case 0x12: /* 640x480-4 */ + case 0x13: /* 320-200-8 */ + case 0x6a: /* 800x600-4 (VESA) */ + return true; + default: + return __screen_info_has_ega_gfx(mode); + } +} + +/** + * screen_info_resources() - Get resources from screen_info structure + * @si: the screen_info + * @r: pointer to an array of resource structures + * @num: number of elements in @r: + * + * Returns: + * The number of resources stored in @r on success, or a negative errno code otherwise. + * + * A call to screen_info_resources() returns the resources consumed by the + * screen_info's device or framebuffer. The result is stored in the caller-supplied + * array @r with up to @num elements. The function returns the number of + * initialized elements. + */ +ssize_t screen_info_resources(const struct screen_info *si, struct resource *r, size_t num) +{ + struct resource *pos = r; + unsigned int type = screen_info_video_type(si); + u64 base, size; + + switch (type) { + case VIDEO_TYPE_MDA: + if (num > 0) + resource_init_io_named(pos++, 0x3b0, 12, "mda"); + if (num > 1) + resource_init_io_named(pos++, 0x3bf, 0x01, "mda"); + if (num > 2) + resource_init_mem_named(pos++, 0xb0000, 0x2000, "mda"); + break; + case VIDEO_TYPE_CGA: + if (num > 0) + resource_init_io_named(pos++, 0x3d4, 0x02, "cga"); + if (num > 1) + resource_init_mem_named(pos++, 0xb8000, 0x2000, "cga"); + break; + case VIDEO_TYPE_EGAM: + if (num > 0) + resource_init_io_named(pos++, 0x3bf, 0x10, "ega"); + if (num > 1) + resource_init_mem_named(pos++, 0xb0000, 0x8000, "ega"); + break; + case VIDEO_TYPE_EGAC: + if (num > 0) + resource_init_io_named(pos++, 0x3c0, 0x20, "ega"); + if (num > 1) { + if (__screen_info_has_ega_gfx(si->orig_video_mode)) + resource_init_mem_named(pos++, 0xa0000, 0x10000, "ega"); + else + resource_init_mem_named(pos++, 0xb8000, 0x8000, "ega"); + } + break; + case VIDEO_TYPE_VGAC: + if (num > 0) + resource_init_io_named(pos++, 0x3c0, 0x20, "vga+"); + if (num > 1) { + if (__screen_info_has_vga_gfx(si->orig_video_mode)) + resource_init_mem_named(pos++, 0xa0000, 0x10000, "vga+"); + else + resource_init_mem_named(pos++, 0xb8000, 0x8000, "vga+"); + } + break; + case VIDEO_TYPE_VLFB: + case VIDEO_TYPE_EFI: + base = __screen_info_lfb_base(si); + if (!base) + break; + size = __screen_info_lfb_size(si, type); + if (!size) + break; + if (num > 0) + resource_init_mem_named(pos++, base, size, "lfb"); + break; + case VIDEO_TYPE_PICA_S3: + case VIDEO_TYPE_MIPS_G364: + case VIDEO_TYPE_SGI: + case VIDEO_TYPE_TGAC: + case VIDEO_TYPE_SUN: + case VIDEO_TYPE_SUNPCI: + case VIDEO_TYPE_PMAC: + default: + /* not supported */ + return -EINVAL; + } + + return pos - r; +} +EXPORT_SYMBOL(screen_info_resources); + +/* + * The meaning of depth and bpp for direct-color formats is + * inconsistent: + * + * - DRM format info specifies depth as the number of color + * bits; including alpha, but not including filler bits. + * - Linux' EFI platform code computes lfb_depth from the + * individual color channels, including the reserved bits. + * - VBE 1.1 defines lfb_depth for XRGB1555 as 16, but later + * versions use 15. + * - On the kernel command line, 'bpp' of 32 is usually + * XRGB8888 including the filler bits, but 15 is XRGB1555 + * not including the filler bit. + * + * It is not easily possible to fix this in struct screen_info, + * as this could break UAPI. The best solution is to compute + * bits_per_pixel from the color bits, reserved bits and + * reported lfb_depth, whichever is highest. + */ + +u32 __screen_info_lfb_bits_per_pixel(const struct screen_info *si) +{ + u32 bits_per_pixel = si->lfb_depth; + + if (bits_per_pixel > 8) { + bits_per_pixel = max(max3(si->red_size + si->red_pos, + si->green_size + si->green_pos, + si->blue_size + si->blue_pos), + si->rsvd_size + si->rsvd_pos); + bits_per_pixel = max_t(u32, bits_per_pixel, si->lfb_depth); + } + + return bits_per_pixel; +} +EXPORT_SYMBOL(__screen_info_lfb_bits_per_pixel); |