lib: Add support for off-mode charging splash screen

Introduce the infrastructure required to display an off-mode charging
notification. This is used when a device boots due to power cable
insertion but should remain in a charging state rather than booting
the full operating system.

Changes:
- Add BOOTSPLASH_OFF_MODE_CHARGING to bootsplash_type.
- Define platform_is_off_mode_charging_active() with a weak inline
  fallback to allow platforms to signal off-mode charging status.
- Update bmp_logo.c to recognize "off_mode_charging.bmp" and select
  it as the active logo type when charging is active.
- Modify render_bmp.c to handle layout and rendering for the charging
  logo, including support for footer text if enabled.
- Ensure the rendering flow bails out early after displaying the
  charging notification to prevent standard OS boot splash.

BUG=b:473480933
TEST=Able to build google/fatcat.

Change-Id: Ief4c65eaf0178ff3d736363c3e56acfe1adba14a
Signed-off-by: Subrata Banik <subratabanik@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/91106
Reviewed-by: Kapil Porwal <kapilporwal@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/include/bootsplash.h

@@ -13,6 +13,8 @@ enum bootsplash_type {
 	BOOTSPLASH_CENTER,
 	/* Indicates an optional OEM defined bootsplash logo for footer of the splash screen. */
 	BOOTSPLASH_FOOTER,
+	/* Indicates a off-mode charging bootsplash logo. */
+	BOOTSPLASH_OFF_MODE_CHARGING,
 
 	/* It's used to determine the total number of bootsplash types. */
 	BOOTSPLASH_MAX_NUM,
@@ -171,6 +173,29 @@ bool platform_is_low_battery_shutdown_needed(void);
 static inline bool platform_is_low_battery_shutdown_needed(void) { return false; }
 #endif
 
+/*
+ * Platform specific callbacks for off-mode bootsplash handling.
+ *
+ * These callbacks allow the platform to determine if the device
+ * has booted in off-mode charging to render the appropriate user
+ * notification.
+ */
+#if CONFIG(PLATFORM_HAS_OFF_MODE_CHARGING_INDICATOR)
+/*
+ * platform_is_off_mode_charging_active - Check if off-mode charging is required.
+ *
+ * Returns true if the system should stay in a "charging splash" state
+ * instead of performing a full OS boot or a complete power-off.
+ */
+bool platform_is_off_mode_charging_active(void);
+#else
+/* Inline fallback for platforms without off-mode charging support */
+static inline bool platform_is_off_mode_charging_active(void)
+{
+	return false;
+}
+#endif
+
 /*
  * VGA Mode 12h (640x480 with 16 colors):
  * As per page 13 of https://www.phatcode.net/res/221/files/vbe20.pdf

src/lib/bmp_logo.c

@@ -13,7 +13,8 @@ static const struct cbmem_entry *logo_entry;
 static const char *bootsplash_list[BOOTSPLASH_MAX_NUM] = {
 	[BOOTSPLASH_LOW_BATTERY] = "low_battery.bmp",
 	[BOOTSPLASH_CENTER] = "logo.bmp",
-	[BOOTSPLASH_FOOTER] = "footer_logo.bmp"
+	[BOOTSPLASH_FOOTER] = "footer_logo.bmp",
+	[BOOTSPLASH_OFF_MODE_CHARGING] = "off_mode_charging.bmp"
 };
 
 /*
@@ -60,6 +61,9 @@ void *bmp_load_logo(size_t *logo_size)
 	if (platform_is_low_battery_shutdown_needed())
 		type = BOOTSPLASH_LOW_BATTERY;
 
+	if (platform_is_off_mode_charging_active())
+		type = BOOTSPLASH_OFF_MODE_CHARGING;
+
 	return bmp_load_logo_by_type(type, logo_size);
 }
 

src/lib/render_bmp.c

@@ -576,7 +576,8 @@ static void get_logo_layout(
 	if (!config || !logo_halignment || !logo_valignment || !logo_bottom_margin)
 		return;
 
-	if (logo_type == BOOTSPLASH_LOW_BATTERY || logo_type == BOOTSPLASH_CENTER) {
+	if (logo_type == BOOTSPLASH_LOW_BATTERY || logo_type == BOOTSPLASH_CENTER ||
+			logo_type == BOOTSPLASH_OFF_MODE_CHARGING) {
 		*logo_halignment = config->halignment;
 		*logo_valignment = config->valignment;
 		/* Override logo alignment if the default screen orientation is not normal */
@@ -710,6 +711,16 @@ void render_logo_to_framebuffer(struct logo_config *config)
 		return;
 	}
 
+	/*
+	 * If the device has booted due to cable power insertion aka off-mode then display
+	 * off-mode charging user notification and bail out early.
+	 */
+	if (platform_is_off_mode_charging_active()) {
+		if (load_and_render_logo_to_framebuffer(BOOTSPLASH_OFF_MODE_CHARGING, config) != 0)
+			printk(BIOS_ERR, "%s: Failed to render off-mode charging logo.\n", __func__);
+		return;
+	}
+
 	/* Render the main logo */
 	if (load_and_render_logo_to_framebuffer(BOOTSPLASH_CENTER, config) != 0) {
 		printk(BIOS_ERR, "%s: Failed to render main splash screen logo.\n", __func__);