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, 151 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/dvo.h b/drivers/gpu/drm/i915/dvo.h
new file mode 100644
index 0000000..e80866c
--- /dev/null
+++ b/drivers/gpu/drm/i915/dvo.h
@@ -0,0 +1,151 @@
+/*
+ * Copyright © 2006 Eric Anholt
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting documentation, and
+ * that the name of the copyright holders not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission.  The copyright holders make no representations
+ * about the suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ */
+
+#ifndef _INTEL_DVO_H
+#define _INTEL_DVO_H
+
+#include <linux/i2c.h>
+#include "drmP.h"
+#include "drm.h"
+#include "drm_crtc.h"
+#include "intel_drv.h"
+
+struct intel_dvo_device {
+	char *name;
+	int type;
+	/* DVOA/B/C output register */
+	u32 dvo_reg;
+	/* GPIO register used for i2c bus to control this device */
+	u32 gpio;
+	int slave_addr;
+	struct intel_i2c_chan *i2c_bus;
+
+	const struct intel_dvo_dev_ops *dev_ops;
+	void *dev_priv;
+
+	struct drm_display_mode *panel_fixed_mode;
+	bool panel_wants_dither;
+};
+
+struct intel_dvo_dev_ops {
+	/*
+	 * Initialize the device at startup time.
+	 * Returns NULL if the device does not exist.
+	 */
+	bool (*init)(struct intel_dvo_device *dvo,
+		     struct intel_i2c_chan *i2cbus);
+
+	/*
+	 * Called to allow the output a chance to create properties after the
+	 * RandR objects have been created.
+	 */
+	void (*create_resources)(struct intel_dvo_device *dvo);
+
+	/*
+	 * Turn on/off output or set intermediate power levels if available.
+	 *
+	 * Unsupported intermediate modes drop to the lower power setting.
+	 * If the  mode is DPMSModeOff, the output must be disabled,
+	 * as the DPLL may be disabled afterwards.
+	 */
+	void (*dpms)(struct intel_dvo_device *dvo, int mode);
+
+	/*
+	 * Saves the output's state for restoration on VT switch.
+	 */
+	void (*save)(struct intel_dvo_device *dvo);
+
+	/*
+	 * Restore's the output's state at VT switch.
+	 */
+	void (*restore)(struct intel_dvo_device *dvo);
+
+	/*
+	 * Callback for testing a video mode for a given output.
+	 *
+	 * This function should only check for cases where a mode can't
+	 * be supported on the output specifically, and not represent
+	 * generic CRTC limitations.
+	 *
+	 * \return MODE_OK if the mode is valid, or another MODE_* otherwise.
+	 */
+	int (*mode_valid)(struct intel_dvo_device *dvo,
+			  struct drm_display_mode *mode);
+
+	/*
+	 * Callback to adjust the mode to be set in the CRTC.
+	 *
+	 * This allows an output to adjust the clock or even the entire set of
+	 * timings, which is used for panels with fixed timings or for
+	 * buses with clock limitations.
+	 */
+	bool (*mode_fixup)(struct intel_dvo_device *dvo,
+			   struct drm_display_mode *mode,
+			   struct drm_display_mode *adjusted_mode);
+
+	/*
+	 * Callback for preparing mode changes on an output
+	 */
+	void (*prepare)(struct intel_dvo_device *dvo);
+
+	/*
+	 * Callback for committing mode changes on an output
+	 */
+	void (*commit)(struct intel_dvo_device *dvo);
+
+	/*
+	 * Callback for setting up a video mode after fixups have been made.
+	 *
+	 * This is only called while the output is disabled.  The dpms callback
+	 * must be all that's necessary for the output, to turn the output on
+	 * after this function is called.
+	 */
+	void (*mode_set)(struct intel_dvo_device *dvo,
+			 struct drm_display_mode *mode,
+			 struct drm_display_mode *adjusted_mode);
+
+	/*
+	 * Probe for a connected output, and return detect_status.
+	 */
+	enum drm_connector_status (*detect)(struct intel_dvo_device *dvo);
+
+	/**
+	 * Query the device for the modes it provides.
+	 *
+	 * This function may also update MonInfo, mm_width, and mm_height.
+	 *
+	 * \return singly-linked list of modes or NULL if no modes found.
+	 */
+	struct drm_display_mode *(*get_modes)(struct intel_dvo_device *dvo);
+
+	/**
+	 * Clean up driver-specific bits of the output
+	 */
+	void (*destroy) (struct intel_dvo_device *dvo);
+
+	/**
+	 * Debugging hook to dump device registers to log file
+	 */
+	void (*dump_regs)(struct intel_dvo_device *dvo);
+};
+
+#endif /* _INTEL_DVO_H */