DRM: i915: add mode setting support

This commit adds i915 driver support for the DRM mode setting APIs.
Currently, VGA, LVDS, SDVO DVI & VGA, TV and DVO LVDS outputs are
supported.  HDMI, DisplayPort and additional SDVO output support will
follow.

Support for the mode setting code is controlled by the new 'modeset'
module option.  A new config option, CONFIG_DRM_I915_KMS controls the
default behavior, and whether a PCI ID list is built into the module for
use by user level module utilities.

Note that if mode setting is enabled, user level drivers that access
display registers directly or that don't use the kernel graphics memory
manager will likely corrupt kernel graphics memory, disrupt output
configuration (possibly leading to hangs and/or blank displays), and
prevent panic/oops messages from appearing.  So use caution when
enabling this code; be sure your user level code supports the new
interfaces.

A new SysRq key, 'g', provides emergency support for switching back to
the kernel's framebuffer console; which is useful for testing.

Co-authors: Dave Airlie <airlied@linux.ie>, Hong Liu <hong.liu@intel.com>

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 83 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_modes.c b/drivers/gpu/drm/i915/intel_modes.c
new file mode 100644
index 00000000000..e42019e5d66
--- /dev/null
+++ b/drivers/gpu/drm/i915/intel_modes.c
@@ -0,0 +1,83 @@
+/*
+ * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
+ * Copyright (c) 2007 Intel Corporation
+ *   Jesse Barnes <jesse.barnes@intel.com>
+ *
+ * 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.
+ */
+
+#include <linux/i2c.h>
+#include <linux/fb.h>
+#include "drmP.h"
+#include "intel_drv.h"
+
+/**
+ * intel_ddc_probe
+ *
+ */
+bool intel_ddc_probe(struct intel_output *intel_output)
+{
+	u8 out_buf[] = { 0x0, 0x0};
+	u8 buf[2];
+	int ret;
+	struct i2c_msg msgs[] = {
+		{
+			.addr = 0x50,
+			.flags = 0,
+			.len = 1,
+			.buf = out_buf,
+		},
+		{
+			.addr = 0x50,
+			.flags = I2C_M_RD,
+			.len = 1,
+			.buf = buf,
+		}
+	};
+
+	ret = i2c_transfer(&intel_output->ddc_bus->adapter, msgs, 2);
+	if (ret == 2)
+		return true;
+
+	return false;
+}
+
+/**
+ * intel_ddc_get_modes - get modelist from monitor
+ * @connector: DRM connector device to use
+ *
+ * Fetch the EDID information from @connector using the DDC bus.
+ */
+int intel_ddc_get_modes(struct intel_output *intel_output)
+{
+	struct edid *edid;
+	int ret = 0;
+
+	edid = drm_get_edid(&intel_output->base,
+			    &intel_output->ddc_bus->adapter);
+	if (edid) {
+		drm_mode_connector_update_edid_property(&intel_output->base,
+							edid);
+		ret = drm_add_edid_modes(&intel_output->base, edid);
+		kfree(edid);
+	}
+
+	return ret;
+}