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, 193 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
new file mode 100644
index 000000000000..4ca82a025525
--- /dev/null
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -0,0 +1,193 @@
+/*
+ * 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>
+ *
+ */
+#include "drmP.h"
+#include "drm.h"
+#include "i915_drm.h"
+#include "i915_drv.h"
+#include "intel_bios.h"
+
+
+static void *
+find_section(struct bdb_header *bdb, int section_id)
+{
+        u8 *base = (u8 *)bdb;
+        int index = 0;
+        u16 total, current_size;
+        u8 current_id;
+
+        /* skip to first section */
+        index += bdb->header_size;
+        total = bdb->bdb_size;
+
+        /* walk the sections looking for section_id */
+        while (index < total) {
+                current_id = *(base + index);
+                index++;
+                current_size = *((u16 *)(base + index));
+                index += 2;
+                if (current_id == section_id)
+                        return base + index;
+                index += current_size;
+        }
+
+        return NULL;
+}
+
+/* Try to find panel data */
+static void
+parse_panel_data(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
+{
+        struct bdb_lvds_options *lvds_options;
+        struct bdb_lvds_lfp_data *lvds_lfp_data;
+        struct bdb_lvds_lfp_data_entry *entry;
+        struct lvds_dvo_timing *dvo_timing;
+        struct drm_display_mode *panel_fixed_mode;
+
+        /* Defaults if we can't find VBT info */
+        dev_priv->lvds_dither = 0;
+        dev_priv->lvds_vbt = 0;
+
+        lvds_options = find_section(bdb, BDB_LVDS_OPTIONS);
+        if (!lvds_options)
+                return;
+
+        dev_priv->lvds_dither = lvds_options->pixel_dither;
+        if (lvds_options->panel_type == 0xff)
+                return;
+
+        lvds_lfp_data = find_section(bdb, BDB_LVDS_LFP_DATA);
+        if (!lvds_lfp_data)
+                return;
+
+        dev_priv->lvds_vbt = 1;
+
+        entry = &lvds_lfp_data->data[lvds_options->panel_type];
+        dvo_timing = &entry->dvo_timing;
+
+        panel_fixed_mode = drm_calloc(1, sizeof(*panel_fixed_mode),
+                                      DRM_MEM_DRIVER);
+
+        panel_fixed_mode->hdisplay = (dvo_timing->hactive_hi << 8) |
+                dvo_timing->hactive_lo;
+        panel_fixed_mode->hsync_start = panel_fixed_mode->hdisplay +
+                ((dvo_timing->hsync_off_hi << 8) | dvo_timing->hsync_off_lo);
+        panel_fixed_mode->hsync_end = panel_fixed_mode->hsync_start +
+                dvo_timing->hsync_pulse_width;
+        panel_fixed_mode->htotal = panel_fixed_mode->hdisplay +
+                ((dvo_timing->hblank_hi << 8) | dvo_timing->hblank_lo);
+
+        panel_fixed_mode->vdisplay = (dvo_timing->vactive_hi << 8) |
+                dvo_timing->vactive_lo;
+        panel_fixed_mode->vsync_start = panel_fixed_mode->vdisplay +
+                dvo_timing->vsync_off;
+        panel_fixed_mode->vsync_end = panel_fixed_mode->vsync_start +
+                dvo_timing->vsync_pulse_width;
+        panel_fixed_mode->vtotal = panel_fixed_mode->vdisplay +
+                ((dvo_timing->vblank_hi << 8) | dvo_timing->vblank_lo);
+        panel_fixed_mode->clock = dvo_timing->clock * 10;
+        panel_fixed_mode->type = DRM_MODE_TYPE_PREFERRED;
+
+        drm_mode_set_name(panel_fixed_mode);
+
+        dev_priv->vbt_mode = panel_fixed_mode;
+
+        DRM_DEBUG("Found panel mode in BIOS VBT tables:\n");
+        drm_mode_debug_printmodeline(panel_fixed_mode);
+
+        return;
+}
+
+static void
+parse_general_features(struct drm_i915_private *dev_priv,
+                       struct bdb_header *bdb)
+{
+        struct bdb_general_features *general;
+
+        /* Set sensible defaults in case we can't find the general block */
+        dev_priv->int_tv_support = 1;
+        dev_priv->int_crt_support = 1;
+
+        general = find_section(bdb, BDB_GENERAL_FEATURES);
+        if (general) {
+                dev_priv->int_tv_support = general->int_tv_support;
+                dev_priv->int_crt_support = general->int_crt_support;
+        }
+}
+
+/**
+ * intel_init_bios - initialize VBIOS settings & find VBT
+ * @dev: DRM device
+ *
+ * Loads the Video BIOS and checks that the VBT exists.  Sets scratch registers
+ * to appropriate values.
+ *
+ * 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.
+ *
+ * Returns 0 on success, nonzero on failure.
+ */
+bool
+intel_init_bios(struct drm_device *dev)
+{
+        struct drm_i915_private *dev_priv = dev->dev_private;
+        struct pci_dev *pdev = dev->pdev;
+        struct vbt_header *vbt = NULL;
+        struct bdb_header *bdb;
+        u8 __iomem *bios;
+        size_t size;
+        int i;
+
+        bios = pci_map_rom(pdev, &size);
+        if (!bios)
+                return -1;
+
+        /* Scour memory looking for the VBT signature */
+        for (i = 0; i + 4 < size; i++) {
+                if (!memcmp(bios + i, "$VBT", 4)) {
+                        vbt = (struct vbt_header *)(bios + i);
+                        break;
+                }
+        }
+
+        if (!vbt) {
+                DRM_ERROR("VBT signature missing\n");
+                pci_unmap_rom(pdev, bios);
+                return -1;
+        }
+
+        bdb = (struct bdb_header *)(bios + i + vbt->bdb_offset);
+
+        /* Grab useful general definitions */
+        parse_general_features(dev_priv, bdb);
+        parse_panel_data(dev_priv, bdb);
+
+        pci_unmap_rom(pdev, bios);
+
+        return 0;
+}