Start interpreting VBT information with the goal of pulling out LVDS timings

for panel fitting.

1 files changed, 126 insertions, 0 deletions

diff --git a/src/i830_bios.c b/src/i830_bios.c
new file mode 100644
index 00000000..a5b7fcd7
--- /dev/null
+++ b/src/i830_bios.c
@@ -0,0 +1,126 @@
+/*
+ * Copyright © 2006 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Authors:
+ *    Eric Anholt <eric@anholt.net>
+ *
+ */
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "xf86.h"
+#include "xf86_ansic.h"
+#include "i830.h"
+#include "i830_bios.h"
+
+#define INTEL_BIOS_8(_addr)	(pI830->VBIOS[_addr])
+#define INTEL_BIOS_16(_addr)	(pI830->VBIOS[_addr] | \
+				 (pI830->VBIOS[_addr + 1] << 8))
+#define INTEL_BIOS_32(_addr)	(pI830->VBIOS[_addr] | \
+				 (pI830->VBIOS[_addr + 1] << 8) \
+				 (pI830->VBIOS[_addr + 2] << 16) \
+				 (pI830->VBIOS[_addr + 3] << 24))
+
+/* XXX */
+#define INTEL_VBIOS_SIZE (64 * 1024)
+
+/**
+ * Loads the Video BIOS and checks that the VBT exists.
+ *
+ * VBT existence is a sanity check that is relied on by other i830_bios.c code.
+ * Note that it would be better to use a BIOS call to get the VBT, as BIOSes may
+ * feed an updated VBT back through that, compared to what we'll fetch using
+ * this method of groping around in the BIOS data.
+ */
+static Bool
+i830GetBIOS(ScrnInfoPtr pScrn)
+{
+    I830Ptr pI830 = I830PTR(pScrn);
+    struct vbt_header *vbt;
+    int vbt_off;
+
+    if (pI830->VBIOS != NULL)
+	return TRUE;
+
+    pI830->VBIOS = xalloc(INTEL_VBIOS_SIZE);
+    if (pI830->VBIOS == NULL)
+	return FALSE;
+
+    if (pI830->pVbe != NULL) {
+	memcpy(pI830->VBIOS, (void *)(pI830->pVbe->pInt10->BIOSseg << 4),
+	       INTEL_VBIOS_SIZE);
+    } else {
+	xf86ReadPciBIOS(0, pI830->PciTag, 0, pI830->VBIOS, INTEL_VBIOS_SIZE);
+    }
+
+    vbt_off = INTEL_BIOS_16(0x1a);
+    if (vbt_off >= INTEL_VBIOS_SIZE) {
+	xf86DrvMsg(pScrn->scrnIndex, X_ERROR, "Bad VBT offset: 0x%x\n",
+		   vbt_off);
+	xfree(pI830->VBIOS);
+	return FALSE;
+    }
+
+    vbt = (struct vbt_header *)(pI830->VBIOS + vbt_off);
+
+    if (memcmp(vbt->signature, "$VBT", 4) != 0) {
+	xf86DrvMsg(pScrn->scrnIndex, X_ERROR, "Bad VBT signature\n");
+	xfree(pI830->VBIOS);
+	return FALSE;
+    }
+
+    return TRUE;
+}
+
+Bool
+i830GetLVDSInfoFromBIOS(ScrnInfoPtr pScrn)
+{
+    I830Ptr pI830 = I830PTR(pScrn);
+    struct vbt_header *vbt;
+    struct bdb_header *bdb;
+    int vbt_off, bdb_block_off, block_size;
+
+    if (!i830GetBIOS(pScrn))
+	return FALSE;
+
+    vbt_off = INTEL_BIOS_16(0x1a);
+    vbt = (struct vbt_header *)(pI830->VBIOS + vbt_off);
+    bdb = (struct bdb_header *)(pI830->VBIOS + vbt_off + vbt->bdb_offset);
+
+    if (memcmp(bdb->signature, "BIOS_DATA_BLOCK ", 16) != 0) {
+	xf86DrvMsg(pScrn->scrnIndex, X_ERROR, "Bad BDB signature\n");
+	return FALSE;
+    }
+
+    for (bdb_block_off = bdb->header_size; bdb_block_off < bdb->bdb_size;
+	 bdb_block_off += block_size)
+    {
+	int start = vbt_off + vbt->bdb_offset + bdb_block_off;
+	int id;
+
+	id = INTEL_BIOS_8(start);
+	block_size = INTEL_BIOS_16(start + 1) + 3;
+	xf86DrvMsg(pScrn->scrnIndex, X_INFO, "Found BDB block type %d\n", id);
+    }
+    return TRUE;
+}