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authorAaron Durbin <adurbin@chromium.org>2020-08-20 10:15:06 -0600
committerAaron Durbin <adurbin@chromium.org>2020-08-21 16:19:37 +0000
commit77a062e98cce6eb3f23c4aa12e7d6131cd2cf77b (patch)
tree10978b3e1afddb71497b586b5f3e36b610d411a7 /src
parent80bc09156445f1d759cf330d94800be30f70e940 (diff)
downloadcoreboot-77a062e98cce6eb3f23c4aa12e7d6131cd2cf77b.tar.xz
soc/amd/common: add rudimentary ATIF support
The Linux kenerl driver for AMD gpu currently has a floor value of 12 for brightness settings (AMDGPU_DM_DEFAULT_MIN_BACKLIGHT). AMD indicates they did this because they were concerned with certain panels flickering at lower backlight values. However, for unaffected panels it's desirable to be able to have the panel "turn off" at the lowest backlight setting. The only way to do that is to provide ATIF bindings that indicate backlight range. Option SOC_AMD_COMMON_BLOCK_GRAPHICS_ATIF is added to provide a full range for the backlight setting. If needed, this path can be built upon for fuller support, but for the time being this is the only thing necessary to make the backlight be full range. BUG=b:163583825 Change-Id: If76801a8daf6a5e56ba7d118956f3ebce74e567a Signed-off-by: Aaron Durbin <adurbin@chromium.org> Reviewed-on: https://review.coreboot.org/c/coreboot/+/44642 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Furquan Shaikh <furquan@google.com>
Diffstat (limited to 'src')
-rw-r--r--src/soc/amd/common/block/graphics/Kconfig8
-rw-r--r--src/soc/amd/common/block/graphics/graphics.c101
2 files changed, 109 insertions, 0 deletions
diff --git a/src/soc/amd/common/block/graphics/Kconfig b/src/soc/amd/common/block/graphics/Kconfig
index 8aa2a20a3c..4cda353c5f 100644
--- a/src/soc/amd/common/block/graphics/Kconfig
+++ b/src/soc/amd/common/block/graphics/Kconfig
@@ -3,3 +3,11 @@ config SOC_AMD_COMMON_BLOCK_GRAPHICS
default n
help
Select this option to use AMD common graphics driver support.
+
+config SOC_AMD_COMMON_BLOCK_GRAPHICS_ATIF
+ bool
+ depends on SOC_AMD_COMMON_BLOCK_GRAPHICS
+ help
+ Select this option to provide ATIF method with display brightness querying.
+ Currently, the exported values only open up 0-255 as the brightness range for
+ the display.
diff --git a/src/soc/amd/common/block/graphics/graphics.c b/src/soc/amd/common/block/graphics/graphics.c
index 466a91c666..24cabfe454 100644
--- a/src/soc/amd/common/block/graphics/graphics.c
+++ b/src/soc/amd/common/block/graphics/graphics.c
@@ -1,13 +1,114 @@
/* SPDX-License-Identifier: GPL-2.0-or-later */
#include <acpi/acpi_device.h>
+#include <acpi/acpigen.h>
#include <device/pci.h>
#include <device/pci_ids.h>
+#define ATIF_FUNCTION_VERIFY_INTERFACE 0x0
+struct atif_verify_interface_output {
+ uint16_t size; /* Size of this object, including size field */
+ uint16_t version;
+ uint32_t supported_notifications;
+ uint32_t supported_functions; /* Bit n set if function n+1 supported. */
+};
+
+#define ATIF_FUNCTION_QUERY_BRIGHTNESS_TRANSFER_CHARACTERISTICS 0x10
+# define ATIF_QBTC_REQUEST_LCD1 0
+/* error codes */
+# define ATIF_QBTC_ERROR_CODE_SUCCESS 0
+# define ATIF_QBTC_ERROR_CODE_FAILURE 1
+# define ATIF_QBTC_ERROR_CODE_DEVICE_NOT_SUPPORTED 2
+struct atif_brightness_input {
+ uint16_t size;
+ /* ATIF doc indicates this field is a word, but the kernel drivers uses a byte. */
+ uint8_t requested_display;
+};
+struct atif_brightness_output {
+ uint16_t size; /* Size of this object, including size field. */
+ uint16_t flags; /* Currently all reserved. */
+ uint8_t error_code;
+ /* default brightness fields currently ignored by Linux driver. */
+ uint8_t default_brightness_ac; /* Percentage brightness when connected to AC. */
+ uint8_t default_brightness_dc; /* Percentage brightness when connected to DC. */
+ /* The following 2 fields are the only ones honored by Linux driver currently. */
+ uint8_t min_input_signal_level; /* 0-255 corresponding to 0% */
+ uint8_t max_input_signal_level; /* 0-255 corresponding to 100% */
+ /* Array of data points consisting of:
+ * { uint8_t luminance_level; (percent)
+ * uint8_t input_signal_level; (0-255 in value) }
+ * Linux ignores these fields so no support currently. */
+ uint8_t count_data_points; /* Count of data points. */
+};
+
+static void generate_atif(const struct device *dev)
+{
+ struct atif_verify_interface_output verify_output = {
+ .size = sizeof(verify_output),
+ .version = 1,
+ .supported_functions =
+ BIT(ATIF_FUNCTION_QUERY_BRIGHTNESS_TRANSFER_CHARACTERISTICS - 1),
+ };
+ struct atif_brightness_output brightness_error = {
+ .size = sizeof(brightness_error),
+ .error_code = ATIF_QBTC_ERROR_CODE_DEVICE_NOT_SUPPORTED,
+ };
+ struct atif_brightness_output brightness_out = {
+ .size = sizeof(brightness_out),
+ .error_code = ATIF_QBTC_ERROR_CODE_SUCCESS,
+ .min_input_signal_level = 0,
+ .max_input_signal_level = 255,
+ };
+
+ /* Scope (\_SB.PCI0.PBRA.IGFX) */
+ acpigen_write_scope(acpi_device_path(dev));
+ /* Method (ATIF, 2, NotSerialized) */
+ acpigen_write_method("ATIF", 2);
+ /* ToInteger (Arg0, Local0) */
+ acpigen_write_to_integer(ARG0_OP, LOCAL0_OP);
+
+ /* If ((Local0 == Zero)) */
+ acpigen_write_if_lequal_op_int(LOCAL0_OP, ATIF_FUNCTION_VERIFY_INTERFACE);
+ /* Return (Buffer (0x0C) { ... } */
+ acpigen_write_return_byte_buffer((uint8_t *)(void *)&verify_output,
+ sizeof(verify_output));
+ acpigen_pop_len(); /* if (LEqual(Local0, 0) */
+
+ /* ElseIf ((Local0 == 0x10)) */
+ acpigen_write_else();
+ acpigen_write_if_lequal_op_int(LOCAL0_OP,
+ ATIF_FUNCTION_QUERY_BRIGHTNESS_TRANSFER_CHARACTERISTICS);
+ /* CreateByteField (Arg1, 0x02, DISP) */
+ acpigen_write_create_byte_field(ARG1_OP,
+ offsetof(struct atif_brightness_input, requested_display), "DISP");
+ /* ToInteger (DISP, Local1) */
+ acpigen_write_to_integer_from_namestring("DISP", LOCAL1_OP);
+ /* If ((Local1 == Zero)) */
+ acpigen_write_if_lequal_op_int(LOCAL1_OP, ATIF_QBTC_REQUEST_LCD1);
+ /* Return (Buffer (0x0A) { ... } */
+ acpigen_write_return_byte_buffer((uint8_t *)(void *)&brightness_out,
+ sizeof(brightness_out));
+ acpigen_pop_len(); /* if (LEqual(Local2, ATIF_QBTC_REQUEST_LCD1) */
+ /* Else */
+ acpigen_write_else();
+ /* Return (Buffer (0x0A) */
+ acpigen_write_return_byte_buffer((uint8_t *)(void *)&brightness_error,
+ sizeof(brightness_error));
+ acpigen_pop_len(); /* else */
+
+ acpigen_pop_len(); /* if (LEqual(Local0, 0x10) */
+ acpigen_pop_len(); /* else */
+
+ acpigen_pop_len(); /* Method */
+ acpigen_pop_len(); /* Scope */
+}
+
static void graphics_fill_ssdt(const struct device *dev)
{
acpi_device_write_pci_dev(dev);
pci_rom_ssdt(dev);
+ if (CONFIG(SOC_AMD_COMMON_BLOCK_GRAPHICS_ATIF))
+ generate_atif(dev);
}
static const char *graphics_acpi_name(const struct device *dev)