drivers/gfx/generic: Add support for gpio based EPS
Add support to control EPS via a PCH gpio
Change-Id: I6f570fd43e1649fb23255b0890e01086e34f844a
Signed-off-by: Rajat Jain <rajatja@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/39154
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Mathew King <mathewk@chromium.org>
diff --git a/src/drivers/gfx/generic/generic.c b/src/drivers/gfx/generic/generic.c
index 8488040..0b3fcca 100644
--- a/src/drivers/gfx/generic/generic.c
+++ b/src/drivers/gfx/generic/generic.c
@@ -24,6 +24,11 @@
#define ACPI_DSM_PRIVACY_SCREEN_UUID "C7033113-8720-4CEB-9090-9D52B3E52D73"
+#define ACPI_METHOD_EPS_PRESENT "EPSP"
+#define ACPI_METHOD_EPS_STATE "EPSS"
+#define ACPI_METHOD_EPS_ENABLE "EPSE"
+#define ACPI_METHOD_EPS_DISABLE "EPSD"
+
static void privacy_screen_detect_cb(void *arg)
{
struct drivers_gfx_generic_privacy_screen_config *config = arg;
@@ -62,6 +67,52 @@
privacy_screen_disable_cb,
};
+static void privacy_gpio_acpigen(struct acpi_gpio *gpio)
+{
+ /* EPS Present */
+ acpigen_write_method(ACPI_METHOD_EPS_PRESENT, 0);
+ acpigen_write_return_byte(1);
+ acpigen_pop_len();
+
+ /* EPS State */
+ acpigen_write_method(ACPI_METHOD_EPS_STATE, 0);
+ acpigen_get_rx_gpio(gpio);
+ acpigen_emit_byte(RETURN_OP);
+ acpigen_emit_byte(LOCAL0_OP);
+ acpigen_pop_len();
+
+ /* EPS Enable */
+ acpigen_write_method(ACPI_METHOD_EPS_ENABLE, 0);
+ acpigen_enable_tx_gpio(gpio);
+ acpigen_pop_len();
+
+ /* EPS Disable */
+ acpigen_write_method(ACPI_METHOD_EPS_DISABLE, 0);
+ acpigen_disable_tx_gpio(gpio);
+ acpigen_pop_len();
+}
+
+static void gfx_fill_privacy_screen_dsm(
+ struct drivers_gfx_generic_privacy_screen_config *privacy)
+{
+ if (!privacy->enabled)
+ return;
+
+ /* Populate ACPI methods, if EPS controlled via gpio */
+ if (privacy->gpio.pin_count == 1) {
+ privacy_gpio_acpigen(&privacy->gpio);
+ privacy->detect_function = ACPI_METHOD_EPS_PRESENT;
+ privacy->status_function = ACPI_METHOD_EPS_STATE;
+ privacy->enable_function = ACPI_METHOD_EPS_ENABLE;
+ privacy->disable_function = ACPI_METHOD_EPS_DISABLE;
+ }
+
+ acpigen_write_dsm(ACPI_DSM_PRIVACY_SCREEN_UUID,
+ privacy_screen_callbacks,
+ ARRAY_SIZE(privacy_screen_callbacks),
+ privacy);
+}
+
static void gfx_fill_ssdt_generator(struct device *dev)
{
size_t i;
@@ -69,7 +120,7 @@
const char *scope = acpi_device_scope(dev);
- if (!scope)
+ if (!scope || !dev->enabled)
return;
acpigen_write_scope(scope);
@@ -85,17 +136,9 @@
for (i = 0; i < config->device_count; i++) {
acpigen_write_device(config->device[i].name);
-
acpigen_write_name_integer("_ADR", config->device[i].addr);
acpigen_write_name_integer("_STA", 0xF);
-
- if (config->device[i].privacy.enabled) {
- acpigen_write_dsm(ACPI_DSM_PRIVACY_SCREEN_UUID,
- privacy_screen_callbacks,
- ARRAY_SIZE(privacy_screen_callbacks),
- &config->device[i].privacy);
- }
-
+ gfx_fill_privacy_screen_dsm(&config->device[i].privacy);
acpigen_pop_len(); /* Device */
}
acpigen_pop_len(); /* Scope */
@@ -117,7 +160,7 @@
{
struct drivers_gfx_generic_config *config = dev->chip_info;
- if (!config)
+ if (!config || !dev->enabled)
return;
dev->ops = &gfx_ops;
@@ -127,3 +170,14 @@
CHIP_NAME("Generic Graphics Device")
.enable_dev = gfx_enable
};
+
+struct device *find_gfx_dev(void)
+{
+ struct device *dev;
+
+ for (dev = all_devices; dev; dev = dev->next) {
+ if (dev->chip_ops && dev->chip_ops == &drivers_gfx_generic_ops)
+ return dev;
+ }
+ return NULL;
+}