drivers/intel/gma: Add EDID retrieving functions.

Change-Id: I64f2fcc5ad52d6a0188d02b28769001ada718c4f
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/5278
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Tested-by: build bot (Jenkins)

src/drivers/intel/Makefile.inc

@@ -1 +1 @@
-subdirs-$(CONFIG_INTEL_DP) += gma
+subdirs-y += gma

src/drivers/intel/gma/Kconfig

@@ -28,3 +28,7 @@ config INTEL_DDI
 	default n
 	help
 	  helper functions for intel DDI operations
+
+config INTEL_EDID
+	bool
+	default n

src/drivers/intel/gma/Makefile.inc

@@ -19,4 +19,4 @@
 
 ramstage-$(CONFIG_INTEL_DP) += intel_dp.c drm_dp_helper.c
 ramstage-$(CONFIG_INTEL_DDI) += intel_ddi.c
-
+ramstage-$(CONFIG_INTEL_EDID) += edid.c

src/drivers/intel/gma/edid.c

@@ -0,0 +1,80 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2014 Vladimir Serbinenko <phcoder@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; version 2, or (at your option)
+ * any later verion of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+ * MA 02110-1301 USA
+ */
+
+#include <arch/io.h>
+#include <console/console.h>
+#include <delay.h>
+
+#include "i915_reg.h"
+#include "edid.h"
+
+static void wait_rdy(u32 mmio)
+{
+	unsigned try = 100;
+
+	while (try--) {
+		if (read32(mmio + 8) & (1 << 11))
+			return;
+		udelay(10);
+	}
+}
+
+void intel_gmbus_read_edid(u32 mmio, u8 bus, u8 slave, u8 *edid, u32 edid_size)
+{
+	int i;
+
+	slave &= 0x7f;
+	edid_size &= 0x1fc;
+
+	wait_rdy(mmio);
+	/* 100 KHz, hold 0ns,  */
+	write32(mmio + 4 * 0, bus);
+	wait_rdy(mmio);
+	/* Ensure index bits are disabled.  */
+	write32(mmio + 4 * 5, 0);
+	write32(mmio + 4 * 1, 0x46000000 | (slave << 1));
+	wait_rdy(mmio);
+	/* Ensure index bits are disabled.  */
+	write32(mmio + 4 * 5, 0);
+	write32(mmio + 4 * 1, 0x4a000001 | (slave << 1)
+		| (edid_size << 16));
+	for (i = 0; i < edid_size / 4; i++) {
+		u32 reg32;
+		wait_rdy(mmio);
+		reg32 = read32(mmio + 4 * 3);
+		edid[4 * i] = reg32 & 0xff;
+		edid[4 * i + 1] = (reg32 >> 8) & 0xff;
+		edid[4 * i + 2] = (reg32 >> 16) & 0xff;
+		edid[4 * i + 3] = (reg32 >> 24) & 0xff;
+	}
+	wait_rdy(mmio);
+	write32(mmio + 4 * 1, 0x4a800000 | (slave << 1));
+	wait_rdy(mmio);
+	write32(mmio + 4 * 0, 0x48000000);
+	write32(mmio + 4 * 2, 0x00008000);
+
+	printk (BIOS_SPEW, "EDID:\n");
+	for (i = 0; i < 128; i++) {
+		printk (BIOS_SPEW, "%02x ", edid[i]);
+		if ((i & 0xf) == 0xf)
+			printk (BIOS_SPEW, "\n");
+	}
+}

src/drivers/intel/gma/edid.h

@@ -0,0 +1 @@
+void intel_gmbus_read_edid(u32 gmbus_mmio, u8 bus, u8 slave, u8 *edid, u32 edid_size);