mb/google/geralt: Put MIPI panel data in panel_geralt.c

There are eDP and MIPI panels supported in geralt. We put the panels'
specified functions - `power_on()` and `configure_panel_backlight()` in
panel_geralt.c. Also provide the common interface `get_active_panel()`
in panel.c to generalize the display initialization. Since each board
may support a different set of MIPI panels, we put the MIPI data in a
separate file panel_geralt.c.

BUG=b:244208960
TEST=emerge-geralt coreboot

Change-Id: Ie928759e020a916f29f0364201a3cf202dc512c3
Signed-off-by: Bo-Chen Chen <rex-bc.chen@mediatek.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/70404
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Yidi Lin <yidilin@google.com>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
diff --git a/src/mainboard/google/geralt/panel.c b/src/mainboard/google/geralt/panel.c
new file mode 100644
index 0000000..b551943
--- /dev/null
+++ b/src/mainboard/google/geralt/panel.c
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <boardid.h>
+#include <cbfs.h>
+#include <console/console.h>
+#include <edid.h>
+#include <gpio.h>
+#include <soc/gpio_common.h>
+#include <string.h>
+
+#include "gpio.h"
+#include "panel.h"
+
+static void get_mipi_cmd_from_cbfs(struct panel_description *desc)
+{
+	/*
+	 * The CBFS file name is panel-{MANUFACTURER}-${PANEL_NAME}, where MANUFACTURER is 3
+	 * characters and PANEL_NAME is usually 13 characters.
+	 */
+	char cbfs_name[64];
+	static union {
+		u8 raw[4 * 1024];  /* Most panels only need < 2K. */
+		struct panel_serializable_data s;
+	} buffer;
+
+	if (!desc->name) {
+		printk(BIOS_ERR, "Missing panel CBFS file name.\n");
+		return;
+	}
+
+	snprintf(cbfs_name, sizeof(cbfs_name), "panel-%s", desc->name);
+	if (cbfs_load(cbfs_name, buffer.raw, sizeof(buffer)))
+		desc->s = &buffer.s;
+	else
+		printk(BIOS_ERR, "Missing %s in CBFS.\n", cbfs_name);
+}
+
+struct panel_description *get_active_panel(void)
+{
+	uint32_t active_panel_id = panel_id();
+
+	struct panel_description *panel = get_panel_description(active_panel_id);
+	if (!panel || panel->disp_path == DISP_PATH_NONE) {
+		printk(BIOS_ERR, "%s: Panel %u is not supported.\n", __func__, active_panel_id);
+		return NULL;
+	}
+
+	/* For eDP, we will get edid after eDP initialization is done, so we return directly. */
+	if (panel->disp_path == DISP_PATH_EDP) {
+		printk(BIOS_INFO, "%s: Use eDP as the display\n", __func__);
+		return panel;
+	}
+
+	/* We need to find init cmds for MIPI panel from CBFS */
+	get_mipi_cmd_from_cbfs(panel);
+	assert(panel->s);
+
+	const struct edid *edid = &panel->s->edid;
+	const char *name = edid->ascii_string;
+	if (name[0] == '\0') {
+		name = "unknown name";
+		printk(BIOS_INFO, "%s: Found ID %u: '%s %s' %dx%d@%dHz\n", __func__,
+		       active_panel_id, edid->manufacturer_name, name, edid->mode.ha,
+		       edid->mode.va, edid->mode.refresh);
+	}
+	return panel;
+}