From: Rob Clark robdclark@chromium.org
On snapdragon aarch64 laptops, a 'UEFIDisplayInfo' variable is provided to communicate some information about the display. Crutially it has the panel-id, so the appropriate panel driver can be selected. Read this out and stash in /chosen/panel-id so that display driver can use it to pick the appropriate panel.
Signed-off-by: Rob Clark robdclark@chromium.org --- drivers/firmware/efi/libstub/arm-stub.c | 49 +++++++++++++++++++++++++ drivers/firmware/efi/libstub/efistub.h | 2 + drivers/firmware/efi/libstub/fdt.c | 9 +++++ 3 files changed, 60 insertions(+)
diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c index 04e6ecd72cd9..999813252e0d 100644 --- a/drivers/firmware/efi/libstub/arm-stub.c +++ b/drivers/firmware/efi/libstub/arm-stub.c @@ -69,6 +69,53 @@ static struct screen_info *setup_graphics(efi_system_table_t *sys_table_arg) return si; }
+/* + * We (at least currently) don't care about most of the fields, just + * panel_id: + */ +struct mdp_disp_info { + u32 version_info; + u32 pad0[9]; + u32 panel_id; + u32 pad1[17]; +}; + +#define MDP_DISP_INFO_VERSION_MAGIC 0xaa + +static void get_panel_id(efi_system_table_t *sys_table_arg, + unsigned long fdt_addr) +{ + efi_guid_t gop_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID; + efi_status_t status; + struct mdp_disp_info *disp_info; + unsigned long size = 0; + + status = efi_call_runtime(get_variable, L"UEFIDisplayInfo", + &gop_proto, NULL, &size, NULL); + if (status == EFI_NOT_FOUND) + return; + + status = efi_call_early(allocate_pool, EFI_LOADER_DATA, size, + (void **)&disp_info); + if (status != EFI_SUCCESS) + return; + + status = efi_call_runtime(get_variable, L"UEFIDisplayInfo", + &gop_proto, NULL, &size, disp_info); + if (status != EFI_SUCCESS) + goto cleanup; + + if ((disp_info->version_info >> 16) != MDP_DISP_INFO_VERSION_MAGIC) + goto cleanup; + + efi_printk(sys_table_arg, "found a panel-id!\n"); + + set_chosen_panel_id(fdt_addr, disp_info->panel_id); + +cleanup: + efi_call_early(free_pool, disp_info); +} + void install_memreserve_table(efi_system_table_t *sys_table_arg) { struct linux_efi_memreserve *rsv; @@ -229,6 +276,8 @@ unsigned long efi_entry(void *handle, efi_system_table_t *sys_table, if (!fdt_addr) pr_efi(sys_table, "Generating empty DTB\n");
+ get_panel_id(sys_table, fdt_addr); + status = handle_cmdline_files(sys_table, image, cmdline_ptr, "initrd=", efi_get_max_initrd_addr(dram_base, *image_addr), diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h index 1b1dfcaa6fb9..8832cb9a7a40 100644 --- a/drivers/firmware/efi/libstub/efistub.h +++ b/drivers/firmware/efi/libstub/efistub.h @@ -39,6 +39,8 @@ void efi_char16_printk(efi_system_table_t *, efi_char16_t *);
unsigned long get_dram_base(efi_system_table_t *sys_table_arg);
+void set_chosen_panel_id(unsigned long fdt_addr, unsigned panel_id); + efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table, void *handle, unsigned long *new_fdt_addr, diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c index 5440ba17a1c5..cb6ea160a40a 100644 --- a/drivers/firmware/efi/libstub/fdt.c +++ b/drivers/firmware/efi/libstub/fdt.c @@ -200,6 +200,15 @@ static efi_status_t update_fdt_memmap(void *fdt, struct efi_boot_memmap *map) return EFI_SUCCESS; }
+void set_chosen_panel_id(unsigned long fdt_addr, unsigned panel_id) +{ + void *fdt = (void *)fdt_addr; + int node = fdt_subnode_offset(fdt, 0, "chosen"); + u32 fdt_val32 = cpu_to_fdt32(panel_id); + + fdt_setprop_var(fdt, node, "panel-id", fdt_val32); +} + #ifndef EFI_FDT_ALIGN # define EFI_FDT_ALIGN EFI_PAGE_SIZE #endif