DRM: add mode setting support

Add mode setting support to the DRM layer.

This is a fairly big chunk of work that allows DRM drivers to provide
full output control and configuration capabilities to userspace.  It was
motivated by several factors:
  - the fb layer's APIs aren't suited for anything but simple
    configurations
  - coordination between the fb layer, DRM layer, and various userspace
    drivers is poor to non-existent (radeonfb excepted)
  - user level mode setting drivers makes displaying panic & oops
    messages more difficult
  - suspend/resume of graphics state is possible in many more
    configurations with kernel level support

This commit just adds the core DRM part of the mode setting APIs.
Driver specific commits using these new structure and APIs will follow.

Co-authors: Jesse Barnes <jbarnes@virtuousgeek.org>, Jakob Bornecrantz <jakob@tungstengraphics.com>
Contributors: Alan Hourihane <alanh@tungstengraphics.com>, Maarten Maathuis <madman2003@gmail.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, 576 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
new file mode 100644
index 00000000000..c9b80fdd463
--- /dev/null
+++ b/drivers/gpu/drm/drm_modes.c
@@ -0,0 +1,576 @@
+/*
+ * The list_sort function is (presumably) licensed under the GPL (see the
+ * top level "COPYING" file for details).
+ *
+ * The remainder of this file is:
+ *
+ * Copyright © 1997-2003 by The XFree86 Project, Inc.
+ * Copyright © 2007 Dave Airlie
+ * Copyright © 2007-2008 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 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 COPYRIGHT HOLDER(S) OR AUTHOR(S) 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.
+ *
+ * Except as contained in this notice, the name of the copyright holder(s)
+ * and author(s) shall not be used in advertising or otherwise to promote
+ * the sale, use or other dealings in this Software without prior written
+ * authorization from the copyright holder(s) and author(s).
+ */
+
+#include <linux/list.h>
+#include "drmP.h"
+#include "drm.h"
+#include "drm_crtc.h"
+
+/**
+ * drm_mode_debug_printmodeline - debug print a mode
+ * @dev: DRM device
+ * @mode: mode to print
+ *
+ * LOCKING:
+ * None.
+ *
+ * Describe @mode using DRM_DEBUG.
+ */
+void drm_mode_debug_printmodeline(struct drm_display_mode *mode)
+{
+	DRM_DEBUG("Modeline %d:\"%s\" %d %d %d %d %d %d %d %d %d %d 0x%x 0x%x\n",
+		  mode->base.id, mode->name, mode->vrefresh, mode->clock,
+		  mode->hdisplay, mode->hsync_start,
+		  mode->hsync_end, mode->htotal,
+		  mode->vdisplay, mode->vsync_start,
+		  mode->vsync_end, mode->vtotal, mode->type, mode->flags);
+}
+EXPORT_SYMBOL(drm_mode_debug_printmodeline);
+
+/**
+ * drm_mode_set_name - set the name on a mode
+ * @mode: name will be set in this mode
+ *
+ * LOCKING:
+ * None.
+ *
+ * Set the name of @mode to a standard format.
+ */
+void drm_mode_set_name(struct drm_display_mode *mode)
+{
+	snprintf(mode->name, DRM_DISPLAY_MODE_LEN, "%dx%d", mode->hdisplay,
+		 mode->vdisplay);
+}
+EXPORT_SYMBOL(drm_mode_set_name);
+
+/**
+ * drm_mode_list_concat - move modes from one list to another
+ * @head: source list
+ * @new: dst list
+ *
+ * LOCKING:
+ * Caller must ensure both lists are locked.
+ *
+ * Move all the modes from @head to @new.
+ */
+void drm_mode_list_concat(struct list_head *head, struct list_head *new)
+{
+
+	struct list_head *entry, *tmp;
+
+	list_for_each_safe(entry, tmp, head) {
+		list_move_tail(entry, new);
+	}
+}
+EXPORT_SYMBOL(drm_mode_list_concat);
+
+/**
+ * drm_mode_width - get the width of a mode
+ * @mode: mode
+ *
+ * LOCKING:
+ * None.
+ *
+ * Return @mode's width (hdisplay) value.
+ *
+ * FIXME: is this needed?
+ *
+ * RETURNS:
+ * @mode->hdisplay
+ */
+int drm_mode_width(struct drm_display_mode *mode)
+{
+	return mode->hdisplay;
+
+}
+EXPORT_SYMBOL(drm_mode_width);
+
+/**
+ * drm_mode_height - get the height of a mode
+ * @mode: mode
+ *
+ * LOCKING:
+ * None.
+ *
+ * Return @mode's height (vdisplay) value.
+ *
+ * FIXME: is this needed?
+ *
+ * RETURNS:
+ * @mode->vdisplay
+ */
+int drm_mode_height(struct drm_display_mode *mode)
+{
+	return mode->vdisplay;
+}
+EXPORT_SYMBOL(drm_mode_height);
+
+/**
+ * drm_mode_vrefresh - get the vrefresh of a mode
+ * @mode: mode
+ *
+ * LOCKING:
+ * None.
+ *
+ * Return @mode's vrefresh rate or calculate it if necessary.
+ *
+ * FIXME: why is this needed?  shouldn't vrefresh be set already?
+ *
+ * RETURNS:
+ * Vertical refresh rate of @mode x 1000. For precision reasons.
+ */
+int drm_mode_vrefresh(struct drm_display_mode *mode)
+{
+	int refresh = 0;
+	unsigned int calc_val;
+
+	if (mode->vrefresh > 0)
+		refresh = mode->vrefresh;
+	else if (mode->htotal > 0 && mode->vtotal > 0) {
+		/* work out vrefresh the value will be x1000 */
+		calc_val = (mode->clock * 1000);
+
+		calc_val /= mode->htotal;
+		calc_val *= 1000;
+		calc_val /= mode->vtotal;
+
+		refresh = calc_val;
+		if (mode->flags & DRM_MODE_FLAG_INTERLACE)
+			refresh *= 2;
+		if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
+			refresh /= 2;
+		if (mode->vscan > 1)
+			refresh /= mode->vscan;
+	}
+	return refresh;
+}
+EXPORT_SYMBOL(drm_mode_vrefresh);
+
+/**
+ * drm_mode_set_crtcinfo - set CRTC modesetting parameters
+ * @p: mode
+ * @adjust_flags: unused? (FIXME)
+ *
+ * LOCKING:
+ * None.
+ *
+ * Setup the CRTC modesetting parameters for @p, adjusting if necessary.
+ */
+void drm_mode_set_crtcinfo(struct drm_display_mode *p, int adjust_flags)
+{
+	if ((p == NULL) || ((p->type & DRM_MODE_TYPE_CRTC_C) == DRM_MODE_TYPE_BUILTIN))
+		return;
+
+	p->crtc_hdisplay = p->hdisplay;
+	p->crtc_hsync_start = p->hsync_start;
+	p->crtc_hsync_end = p->hsync_end;
+	p->crtc_htotal = p->htotal;
+	p->crtc_hskew = p->hskew;
+	p->crtc_vdisplay = p->vdisplay;
+	p->crtc_vsync_start = p->vsync_start;
+	p->crtc_vsync_end = p->vsync_end;
+	p->crtc_vtotal = p->vtotal;
+
+	if (p->flags & DRM_MODE_FLAG_INTERLACE) {
+		if (adjust_flags & CRTC_INTERLACE_HALVE_V) {
+			p->crtc_vdisplay /= 2;
+			p->crtc_vsync_start /= 2;
+			p->crtc_vsync_end /= 2;
+			p->crtc_vtotal /= 2;
+		}
+
+		p->crtc_vtotal |= 1;
+	}
+
+	if (p->flags & DRM_MODE_FLAG_DBLSCAN) {
+		p->crtc_vdisplay *= 2;
+		p->crtc_vsync_start *= 2;
+		p->crtc_vsync_end *= 2;
+		p->crtc_vtotal *= 2;
+	}
+
+	if (p->vscan > 1) {
+		p->crtc_vdisplay *= p->vscan;
+		p->crtc_vsync_start *= p->vscan;
+		p->crtc_vsync_end *= p->vscan;
+		p->crtc_vtotal *= p->vscan;
+	}
+
+	p->crtc_vblank_start = min(p->crtc_vsync_start, p->crtc_vdisplay);
+	p->crtc_vblank_end = max(p->crtc_vsync_end, p->crtc_vtotal);
+	p->crtc_hblank_start = min(p->crtc_hsync_start, p->crtc_hdisplay);
+	p->crtc_hblank_end = max(p->crtc_hsync_end, p->crtc_htotal);
+
+	p->crtc_hadjusted = false;
+	p->crtc_vadjusted = false;
+}
+EXPORT_SYMBOL(drm_mode_set_crtcinfo);
+
+
+/**
+ * drm_mode_duplicate - allocate and duplicate an existing mode
+ * @m: mode to duplicate
+ *
+ * LOCKING:
+ * None.
+ *
+ * Just allocate a new mode, copy the existing mode into it, and return
+ * a pointer to it.  Used to create new instances of established modes.
+ */
+struct drm_display_mode *drm_mode_duplicate(struct drm_device *dev,
+					    struct drm_display_mode *mode)
+{
+	struct drm_display_mode *nmode;
+	int new_id;
+
+	nmode = drm_mode_create(dev);
+	if (!nmode)
+		return NULL;
+
+	new_id = nmode->base.id;
+	*nmode = *mode;
+	nmode->base.id = new_id;
+	INIT_LIST_HEAD(&nmode->head);
+	return nmode;
+}
+EXPORT_SYMBOL(drm_mode_duplicate);
+
+/**
+ * drm_mode_equal - test modes for equality
+ * @mode1: first mode
+ * @mode2: second mode
+ *
+ * LOCKING:
+ * None.
+ *
+ * Check to see if @mode1 and @mode2 are equivalent.
+ *
+ * RETURNS:
+ * True if the modes are equal, false otherwise.
+ */
+bool drm_mode_equal(struct drm_display_mode *mode1, struct drm_display_mode *mode2)
+{
+	/* do clock check convert to PICOS so fb modes get matched
+	 * the same */
+	if (mode1->clock && mode2->clock) {
+		if (KHZ2PICOS(mode1->clock) != KHZ2PICOS(mode2->clock))
+			return false;
+	} else if (mode1->clock != mode2->clock)
+		return false;
+
+	if (mode1->hdisplay == mode2->hdisplay &&
+	    mode1->hsync_start == mode2->hsync_start &&
+	    mode1->hsync_end == mode2->hsync_end &&
+	    mode1->htotal == mode2->htotal &&
+	    mode1->hskew == mode2->hskew &&
+	    mode1->vdisplay == mode2->vdisplay &&
+	    mode1->vsync_start == mode2->vsync_start &&
+	    mode1->vsync_end == mode2->vsync_end &&
+	    mode1->vtotal == mode2->vtotal &&
+	    mode1->vscan == mode2->vscan &&
+	    mode1->flags == mode2->flags)
+		return true;
+
+	return false;
+}
+EXPORT_SYMBOL(drm_mode_equal);
+
+/**
+ * drm_mode_validate_size - make sure modes adhere to size constraints
+ * @dev: DRM device
+ * @mode_list: list of modes to check
+ * @maxX: maximum width
+ * @maxY: maximum height
+ * @maxPitch: max pitch
+ *
+ * LOCKING:
+ * Caller must hold a lock protecting @mode_list.
+ *
+ * The DRM device (@dev) has size and pitch limits.  Here we validate the
+ * modes we probed for @dev against those limits and set their status as
+ * necessary.
+ */
+void drm_mode_validate_size(struct drm_device *dev,
+			    struct list_head *mode_list,
+			    int maxX, int maxY, int maxPitch)
+{
+	struct drm_display_mode *mode;
+
+	list_for_each_entry(mode, mode_list, head) {
+		if (maxPitch > 0 && mode->hdisplay > maxPitch)
+			mode->status = MODE_BAD_WIDTH;
+
+		if (maxX > 0 && mode->hdisplay > maxX)
+			mode->status = MODE_VIRTUAL_X;
+
+		if (maxY > 0 && mode->vdisplay > maxY)
+			mode->status = MODE_VIRTUAL_Y;
+	}
+}
+EXPORT_SYMBOL(drm_mode_validate_size);
+
+/**
+ * drm_mode_validate_clocks - validate modes against clock limits
+ * @dev: DRM device
+ * @mode_list: list of modes to check
+ * @min: minimum clock rate array
+ * @max: maximum clock rate array
+ * @n_ranges: number of clock ranges (size of arrays)
+ *
+ * LOCKING:
+ * Caller must hold a lock protecting @mode_list.
+ *
+ * Some code may need to check a mode list against the clock limits of the
+ * device in question.  This function walks the mode list, testing to make
+ * sure each mode falls within a given range (defined by @min and @max
+ * arrays) and sets @mode->status as needed.
+ */
+void drm_mode_validate_clocks(struct drm_device *dev,
+			      struct list_head *mode_list,
+			      int *min, int *max, int n_ranges)
+{
+	struct drm_display_mode *mode;
+	int i;
+
+	list_for_each_entry(mode, mode_list, head) {
+		bool good = false;
+		for (i = 0; i < n_ranges; i++) {
+			if (mode->clock >= min[i] && mode->clock <= max[i]) {
+				good = true;
+				break;
+			}
+		}
+		if (!good)
+			mode->status = MODE_CLOCK_RANGE;
+	}
+}
+EXPORT_SYMBOL(drm_mode_validate_clocks);
+
+/**
+ * drm_mode_prune_invalid - remove invalid modes from mode list
+ * @dev: DRM device
+ * @mode_list: list of modes to check
+ * @verbose: be verbose about it
+ *
+ * LOCKING:
+ * Caller must hold a lock protecting @mode_list.
+ *
+ * Once mode list generation is complete, a caller can use this routine to
+ * remove invalid modes from a mode list.  If any of the modes have a
+ * status other than %MODE_OK, they are removed from @mode_list and freed.
+ */
+void drm_mode_prune_invalid(struct drm_device *dev,
+			    struct list_head *mode_list, bool verbose)
+{
+	struct drm_display_mode *mode, *t;
+
+	list_for_each_entry_safe(mode, t, mode_list, head) {
+		if (mode->status != MODE_OK) {
+			list_del(&mode->head);
+			if (verbose) {
+				drm_mode_debug_printmodeline(mode);
+				DRM_DEBUG("Not using %s mode %d\n", mode->name, mode->status);
+			}
+			drm_mode_destroy(dev, mode);
+		}
+	}
+}
+EXPORT_SYMBOL(drm_mode_prune_invalid);
+
+/**
+ * drm_mode_compare - compare modes for favorability
+ * @lh_a: list_head for first mode
+ * @lh_b: list_head for second mode
+ *
+ * LOCKING:
+ * None.
+ *
+ * Compare two modes, given by @lh_a and @lh_b, returning a value indicating
+ * which is better.
+ *
+ * RETURNS:
+ * Negative if @lh_a is better than @lh_b, zero if they're equivalent, or
+ * positive if @lh_b is better than @lh_a.
+ */
+static int drm_mode_compare(struct list_head *lh_a, struct list_head *lh_b)
+{
+	struct drm_display_mode *a = list_entry(lh_a, struct drm_display_mode, head);
+	struct drm_display_mode *b = list_entry(lh_b, struct drm_display_mode, head);
+	int diff;
+
+	diff = ((b->type & DRM_MODE_TYPE_PREFERRED) != 0) -
+		((a->type & DRM_MODE_TYPE_PREFERRED) != 0);
+	if (diff)
+		return diff;
+	diff = b->hdisplay * b->vdisplay - a->hdisplay * a->vdisplay;
+	if (diff)
+		return diff;
+	diff = b->clock - a->clock;
+	return diff;
+}
+
+/* FIXME: what we don't have a list sort function? */
+/* list sort from Mark J Roberts (mjr@znex.org) */
+void list_sort(struct list_head *head,
+	       int (*cmp)(struct list_head *a, struct list_head *b))
+{
+	struct list_head *p, *q, *e, *list, *tail, *oldhead;
+	int insize, nmerges, psize, qsize, i;
+
+	list = head->next;
+	list_del(head);
+	insize = 1;
+	for (;;) {
+		p = oldhead = list;
+		list = tail = NULL;
+		nmerges = 0;
+
+		while (p) {
+			nmerges++;
+			q = p;
+			psize = 0;
+			for (i = 0; i < insize; i++) {
+				psize++;
+				q = q->next == oldhead ? NULL : q->next;
+				if (!q)
+					break;
+			}
+
+			qsize = insize;
+			while (psize > 0 || (qsize > 0 && q)) {
+				if (!psize) {
+					e = q;
+					q = q->next;
+					qsize--;
+					if (q == oldhead)
+						q = NULL;
+				} else if (!qsize || !q) {
+					e = p;
+					p = p->next;
+					psize--;
+					if (p == oldhead)
+						p = NULL;
+				} else if (cmp(p, q) <= 0) {
+					e = p;
+					p = p->next;
+					psize--;
+					if (p == oldhead)
+						p = NULL;
+				} else {
+					e = q;
+					q = q->next;
+					qsize--;
+					if (q == oldhead)
+						q = NULL;
+				}
+				if (tail)
+					tail->next = e;
+				else
+					list = e;
+				e->prev = tail;
+				tail = e;
+			}
+			p = q;
+		}
+
+		tail->next = list;
+		list->prev = tail;
+
+		if (nmerges <= 1)
+			break;
+
+		insize *= 2;
+	}
+
+	head->next = list;
+	head->prev = list->prev;
+	list->prev->next = head;
+	list->prev = head;
+}
+
+/**
+ * drm_mode_sort - sort mode list
+ * @mode_list: list to sort
+ *
+ * LOCKING:
+ * Caller must hold a lock protecting @mode_list.
+ *
+ * Sort @mode_list by favorability, putting good modes first.
+ */
+void drm_mode_sort(struct list_head *mode_list)
+{
+	list_sort(mode_list, drm_mode_compare);
+}
+EXPORT_SYMBOL(drm_mode_sort);
+
+/**
+ * drm_mode_connector_list_update - update the mode list for the connector
+ * @connector: the connector to update
+ *
+ * LOCKING:
+ * Caller must hold a lock protecting @mode_list.
+ *
+ * This moves the modes from the @connector probed_modes list
+ * to the actual mode list. It compares the probed mode against the current
+ * list and only adds different modes. All modes unverified after this point
+ * will be removed by the prune invalid modes.
+ */
+void drm_mode_connector_list_update(struct drm_connector *connector)
+{
+	struct drm_display_mode *mode;
+	struct drm_display_mode *pmode, *pt;
+	int found_it;
+
+	list_for_each_entry_safe(pmode, pt, &connector->probed_modes,
+				 head) {
+		found_it = 0;
+		/* go through current modes checking for the new probed mode */
+		list_for_each_entry(mode, &connector->modes, head) {
+			if (drm_mode_equal(pmode, mode)) {
+				found_it = 1;
+				/* if equal delete the probed mode */
+				mode->status = pmode->status;
+				list_del(&pmode->head);
+				drm_mode_destroy(connector->dev, pmode);
+				break;
+			}
+		}
+
+		if (!found_it) {
+			list_move_tail(&pmode->head, &connector->modes);
+		}
+	}
+}
+EXPORT_SYMBOL(drm_mode_connector_list_update);