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, 525 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
new file mode 100644
index 000000000000..ccecfaf6307b
--- /dev/null
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -0,0 +1,525 @@
+/*
+ * Copyright © 2006-2007 Intel Corporation
+ * Copyright (c) 2006 Dave Airlie <airlied@linux.ie>
+ *
+ * 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>
+ *      Dave Airlie <airlied@linux.ie>
+ *      Jesse Barnes <jesse.barnes@intel.com>
+ */
+
+#include <linux/i2c.h>
+#include "drmP.h"
+#include "drm.h"
+#include "drm_crtc.h"
+#include "drm_edid.h"
+#include "intel_drv.h"
+#include "i915_drm.h"
+#include "i915_drv.h"
+
+/**
+ * Sets the backlight level.
+ *
+ * \param level backlight level, from 0 to intel_lvds_get_max_backlight().
+ */
+static void intel_lvds_set_backlight(struct drm_device *dev, int level)
+{
+        struct drm_i915_private *dev_priv = dev->dev_private;
+        u32 blc_pwm_ctl;
+
+        blc_pwm_ctl = I915_READ(BLC_PWM_CTL) & ~BACKLIGHT_DUTY_CYCLE_MASK;
+        I915_WRITE(BLC_PWM_CTL, (blc_pwm_ctl |
+                                 (level << BACKLIGHT_DUTY_CYCLE_SHIFT)));
+}
+
+/**
+ * Returns the maximum level of the backlight duty cycle field.
+ */
+static u32 intel_lvds_get_max_backlight(struct drm_device *dev)
+{
+        struct drm_i915_private *dev_priv = dev->dev_private;
+
+        return ((I915_READ(BLC_PWM_CTL) & BACKLIGHT_MODULATION_FREQ_MASK) >>
+                BACKLIGHT_MODULATION_FREQ_SHIFT) * 2;
+}
+
+/**
+ * Sets the power state for the panel.
+ */
+static void intel_lvds_set_power(struct drm_device *dev, bool on)
+{
+        struct drm_i915_private *dev_priv = dev->dev_private;
+        u32 pp_status;
+
+        if (on) {
+                I915_WRITE(PP_CONTROL, I915_READ(PP_CONTROL) |
+                           POWER_TARGET_ON);
+                do {
+                        pp_status = I915_READ(PP_STATUS);
+                } while ((pp_status & PP_ON) == 0);
+
+                intel_lvds_set_backlight(dev, dev_priv->backlight_duty_cycle);
+        } else {
+                intel_lvds_set_backlight(dev, 0);
+
+                I915_WRITE(PP_CONTROL, I915_READ(PP_CONTROL) &
+                           ~POWER_TARGET_ON);
+                do {
+                        pp_status = I915_READ(PP_STATUS);
+                } while (pp_status & PP_ON);
+        }
+}
+
+static void intel_lvds_dpms(struct drm_encoder *encoder, int mode)
+{
+        struct drm_device *dev = encoder->dev;
+
+        if (mode == DRM_MODE_DPMS_ON)
+                intel_lvds_set_power(dev, true);
+        else
+                intel_lvds_set_power(dev, false);
+
+        /* XXX: We never power down the LVDS pairs. */
+}
+
+static void intel_lvds_save(struct drm_connector *connector)
+{
+        struct drm_device *dev = connector->dev;
+        struct drm_i915_private *dev_priv = dev->dev_private;
+
+        dev_priv->savePP_ON = I915_READ(PP_ON_DELAYS);
+        dev_priv->savePP_OFF = I915_READ(PP_OFF_DELAYS);
+        dev_priv->savePP_CONTROL = I915_READ(PP_CONTROL);
+        dev_priv->savePP_DIVISOR = I915_READ(PP_DIVISOR);
+        dev_priv->saveBLC_PWM_CTL = I915_READ(BLC_PWM_CTL);
+        dev_priv->backlight_duty_cycle = (dev_priv->saveBLC_PWM_CTL &
+                                       BACKLIGHT_DUTY_CYCLE_MASK);
+
+        /*
+         * If the light is off at server startup, just make it full brightness
+         */
+        if (dev_priv->backlight_duty_cycle == 0)
+                dev_priv->backlight_duty_cycle =
+                        intel_lvds_get_max_backlight(dev);
+}
+
+static void intel_lvds_restore(struct drm_connector *connector)
+{
+        struct drm_device *dev = connector->dev;
+        struct drm_i915_private *dev_priv = dev->dev_private;
+
+        I915_WRITE(BLC_PWM_CTL, dev_priv->saveBLC_PWM_CTL);
+        I915_WRITE(PP_ON_DELAYS, dev_priv->savePP_ON);
+        I915_WRITE(PP_OFF_DELAYS, dev_priv->savePP_OFF);
+        I915_WRITE(PP_DIVISOR, dev_priv->savePP_DIVISOR);
+        I915_WRITE(PP_CONTROL, dev_priv->savePP_CONTROL);
+        if (dev_priv->savePP_CONTROL & POWER_TARGET_ON)
+                intel_lvds_set_power(dev, true);
+        else
+                intel_lvds_set_power(dev, false);
+}
+
+static int intel_lvds_mode_valid(struct drm_connector *connector,
+                                 struct drm_display_mode *mode)
+{
+        struct drm_device *dev = connector->dev;
+        struct drm_i915_private *dev_priv = dev->dev_private;
+        struct drm_display_mode *fixed_mode = dev_priv->panel_fixed_mode;
+
+        if (fixed_mode) {
+                if (mode->hdisplay > fixed_mode->hdisplay)
+                        return MODE_PANEL;
+                if (mode->vdisplay > fixed_mode->vdisplay)
+                        return MODE_PANEL;
+        }
+
+        return MODE_OK;
+}
+
+static bool intel_lvds_mode_fixup(struct drm_encoder *encoder,
+                                  struct drm_display_mode *mode,
+                                  struct drm_display_mode *adjusted_mode)
+{
+        struct drm_device *dev = encoder->dev;
+        struct drm_i915_private *dev_priv = dev->dev_private;
+        struct intel_crtc *intel_crtc = to_intel_crtc(encoder->crtc);
+        struct drm_encoder *tmp_encoder;
+
+        /* Should never happen!! */
+        if (!IS_I965G(dev) && intel_crtc->pipe == 0) {
+                printk(KERN_ERR "Can't support LVDS on pipe A\n");
+                return false;
+        }
+
+        /* Should never happen!! */
+        list_for_each_entry(tmp_encoder, &dev->mode_config.encoder_list, head) {
+                if (tmp_encoder != encoder && tmp_encoder->crtc == encoder->crtc) {
+                        printk(KERN_ERR "Can't enable LVDS and another "
+                               "encoder on the same pipe\n");
+                        return false;
+                }
+        }
+
+        /*
+         * If we have timings from the BIOS for the panel, put them in
+         * to the adjusted mode.  The CRTC will be set up for this mode,
+         * with the panel scaling set up to source from the H/VDisplay
+         * of the original mode.
+         */
+        if (dev_priv->panel_fixed_mode != NULL) {
+                adjusted_mode->hdisplay = dev_priv->panel_fixed_mode->hdisplay;
+                adjusted_mode->hsync_start =
+                        dev_priv->panel_fixed_mode->hsync_start;
+                adjusted_mode->hsync_end =
+                        dev_priv->panel_fixed_mode->hsync_end;
+                adjusted_mode->htotal = dev_priv->panel_fixed_mode->htotal;
+                adjusted_mode->vdisplay = dev_priv->panel_fixed_mode->vdisplay;
+                adjusted_mode->vsync_start =
+                        dev_priv->panel_fixed_mode->vsync_start;
+                adjusted_mode->vsync_end =
+                        dev_priv->panel_fixed_mode->vsync_end;
+                adjusted_mode->vtotal = dev_priv->panel_fixed_mode->vtotal;
+                adjusted_mode->clock = dev_priv->panel_fixed_mode->clock;
+                drm_mode_set_crtcinfo(adjusted_mode, CRTC_INTERLACE_HALVE_V);
+        }
+
+        /*
+         * XXX: It would be nice to support lower refresh rates on the
+         * panels to reduce power consumption, and perhaps match the
+         * user's requested refresh rate.
+         */
+
+        return true;
+}
+
+static void intel_lvds_prepare(struct drm_encoder *encoder)
+{
+        struct drm_device *dev = encoder->dev;
+        struct drm_i915_private *dev_priv = dev->dev_private;
+
+        dev_priv->saveBLC_PWM_CTL = I915_READ(BLC_PWM_CTL);
+        dev_priv->backlight_duty_cycle = (dev_priv->saveBLC_PWM_CTL &
+                                       BACKLIGHT_DUTY_CYCLE_MASK);
+
+        intel_lvds_set_power(dev, false);
+}
+
+static void intel_lvds_commit( struct drm_encoder *encoder)
+{
+        struct drm_device *dev = encoder->dev;
+        struct drm_i915_private *dev_priv = dev->dev_private;
+
+        if (dev_priv->backlight_duty_cycle == 0)
+                dev_priv->backlight_duty_cycle =
+                        intel_lvds_get_max_backlight(dev);
+
+        intel_lvds_set_power(dev, true);
+}
+
+static void intel_lvds_mode_set(struct drm_encoder *encoder,
+                                struct drm_display_mode *mode,
+                                struct drm_display_mode *adjusted_mode)
+{
+        struct drm_device *dev = encoder->dev;
+        struct drm_i915_private *dev_priv = dev->dev_private;
+        struct intel_crtc *intel_crtc = to_intel_crtc(encoder->crtc);
+        u32 pfit_control;
+
+        /*
+         * The LVDS pin pair will already have been turned on in the
+         * intel_crtc_mode_set since it has a large impact on the DPLL
+         * settings.
+         */
+
+        /*
+         * Enable automatic panel scaling so that non-native modes fill the
+         * screen.  Should be enabled before the pipe is enabled, according to
+         * register description and PRM.
+         */
+        if (mode->hdisplay != adjusted_mode->hdisplay ||
+            mode->vdisplay != adjusted_mode->vdisplay)
+                pfit_control = (PFIT_ENABLE | VERT_AUTO_SCALE |
+                                HORIZ_AUTO_SCALE | VERT_INTERP_BILINEAR |
+                                HORIZ_INTERP_BILINEAR);
+        else
+                pfit_control = 0;
+
+        if (!IS_I965G(dev)) {
+                if (dev_priv->panel_wants_dither)
+                        pfit_control |= PANEL_8TO6_DITHER_ENABLE;
+        }
+        else
+                pfit_control |= intel_crtc->pipe << PFIT_PIPE_SHIFT;
+
+        I915_WRITE(PFIT_CONTROL, pfit_control);
+}
+
+/**
+ * Detect the LVDS connection.
+ *
+ * This always returns CONNECTOR_STATUS_CONNECTED.  This connector should only have
+ * been set up if the LVDS was actually connected anyway.
+ */
+static enum drm_connector_status intel_lvds_detect(struct drm_connector *connector)
+{
+        return connector_status_connected;
+}
+
+/**
+ * Return the list of DDC modes if available, or the BIOS fixed mode otherwise.
+ */
+static int intel_lvds_get_modes(struct drm_connector *connector)
+{
+        struct drm_device *dev = connector->dev;
+        struct intel_output *intel_output = to_intel_output(connector);
+        struct drm_i915_private *dev_priv = dev->dev_private;
+        int ret = 0;
+
+        ret = intel_ddc_get_modes(intel_output);
+
+        if (ret)
+                return ret;
+
+        /* Didn't get an EDID, so
+         * Set wide sync ranges so we get all modes
+         * handed to valid_mode for checking
+         */
+        connector->display_info.min_vfreq = 0;
+        connector->display_info.max_vfreq = 200;
+        connector->display_info.min_hfreq = 0;
+        connector->display_info.max_hfreq = 200;
+
+        if (dev_priv->panel_fixed_mode != NULL) {
+                struct drm_display_mode *mode;
+
+                mutex_unlock(&dev->mode_config.mutex);
+                mode = drm_mode_duplicate(dev, dev_priv->panel_fixed_mode);
+                drm_mode_probed_add(connector, mode);
+                mutex_unlock(&dev->mode_config.mutex);
+
+                return 1;
+        }
+
+        return 0;
+}
+
+/**
+ * intel_lvds_destroy - unregister and free LVDS structures
+ * @connector: connector to free
+ *
+ * Unregister the DDC bus for this connector then free the driver private
+ * structure.
+ */
+static void intel_lvds_destroy(struct drm_connector *connector)
+{
+        struct intel_output *intel_output = to_intel_output(connector);
+
+        if (intel_output->ddc_bus)
+                intel_i2c_destroy(intel_output->ddc_bus);
+        drm_sysfs_connector_remove(connector);
+        drm_connector_cleanup(connector);
+        kfree(connector);
+}
+
+static const struct drm_encoder_helper_funcs intel_lvds_helper_funcs = {
+        .dpms = intel_lvds_dpms,
+        .mode_fixup = intel_lvds_mode_fixup,
+        .prepare = intel_lvds_prepare,
+        .mode_set = intel_lvds_mode_set,
+        .commit = intel_lvds_commit,
+};
+
+static const struct drm_connector_helper_funcs intel_lvds_connector_helper_funcs = {
+        .get_modes = intel_lvds_get_modes,
+        .mode_valid = intel_lvds_mode_valid,
+        .best_encoder = intel_best_encoder,
+};
+
+static const struct drm_connector_funcs intel_lvds_connector_funcs = {
+        .save = intel_lvds_save,
+        .restore = intel_lvds_restore,
+        .detect = intel_lvds_detect,
+        .fill_modes = drm_helper_probe_single_connector_modes,
+        .destroy = intel_lvds_destroy,
+};
+
+
+static void intel_lvds_enc_destroy(struct drm_encoder *encoder)
+{
+        drm_encoder_cleanup(encoder);
+}
+
+static const struct drm_encoder_funcs intel_lvds_enc_funcs = {
+        .destroy = intel_lvds_enc_destroy,
+};
+
+
+
+/**
+ * intel_lvds_init - setup LVDS connectors on this device
+ * @dev: drm device
+ *
+ * Create the connector, register the LVDS DDC bus, and try to figure out what
+ * modes we can display on the LVDS panel (if present).
+ */
+void intel_lvds_init(struct drm_device *dev)
+{
+        struct drm_i915_private *dev_priv = dev->dev_private;
+        struct intel_output *intel_output;
+        struct drm_connector *connector;
+        struct drm_encoder *encoder;
+        struct drm_display_mode *scan; /* *modes, *bios_mode; */
+        struct drm_crtc *crtc;
+        u32 lvds;
+        int pipe;
+
+        intel_output = kzalloc(sizeof(struct intel_output), GFP_KERNEL);
+        if (!intel_output) {
+                return;
+        }
+
+        connector = &intel_output->base;
+        encoder = &intel_output->enc;
+        drm_connector_init(dev, &intel_output->base, &intel_lvds_connector_funcs,
+                           DRM_MODE_CONNECTOR_LVDS);
+
+        drm_encoder_init(dev, &intel_output->enc, &intel_lvds_enc_funcs,
+                         DRM_MODE_ENCODER_LVDS);
+
+        drm_mode_connector_attach_encoder(&intel_output->base, &intel_output->enc);
+        intel_output->type = INTEL_OUTPUT_LVDS;
+
+        drm_encoder_helper_add(encoder, &intel_lvds_helper_funcs);
+        drm_connector_helper_add(connector, &intel_lvds_connector_helper_funcs);
+        connector->display_info.subpixel_order = SubPixelHorizontalRGB;
+        connector->interlace_allowed = false;
+        connector->doublescan_allowed = false;
+
+
+        /*
+         * LVDS discovery:
+         * 1) check for EDID on DDC
+         * 2) check for VBT data
+         * 3) check to see if LVDS is already on
+         *    if none of the above, no panel
+         * 4) make sure lid is open
+         *    if closed, act like it's not there for now
+         */
+
+        /* Set up the DDC bus. */
+        intel_output->ddc_bus = intel_i2c_create(dev, GPIOC, "LVDSDDC_C");
+        if (!intel_output->ddc_bus) {
+                dev_printk(KERN_ERR, &dev->pdev->dev, "DDC bus registration "
+                           "failed.\n");
+                goto failed;
+        }
+
+        /*
+         * Attempt to get the fixed panel mode from DDC.  Assume that the
+         * preferred mode is the right one.
+         */
+        intel_ddc_get_modes(intel_output);
+
+        list_for_each_entry(scan, &connector->probed_modes, head) {
+                mutex_lock(&dev->mode_config.mutex);
+                if (scan->type & DRM_MODE_TYPE_PREFERRED) {
+                        dev_priv->panel_fixed_mode =
+                                drm_mode_duplicate(dev, scan);
+                        mutex_unlock(&dev->mode_config.mutex);
+                        goto out; /* FIXME: check for quirks */
+                }
+                mutex_unlock(&dev->mode_config.mutex);
+        }
+
+        /* Failed to get EDID, what about VBT? */
+        if (dev_priv->vbt_mode) {
+                mutex_lock(&dev->mode_config.mutex);
+                dev_priv->panel_fixed_mode =
+                        drm_mode_duplicate(dev, dev_priv->vbt_mode);
+                mutex_unlock(&dev->mode_config.mutex);
+        }
+
+        /*
+         * If we didn't get EDID, try checking if the panel is already turned
+         * on.  If so, assume that whatever is currently programmed is the
+         * correct mode.
+         */
+        lvds = I915_READ(LVDS);
+        pipe = (lvds & LVDS_PIPEB_SELECT) ? 1 : 0;
+        crtc = intel_get_crtc_from_pipe(dev, pipe);
+
+        if (crtc && (lvds & LVDS_PORT_EN)) {
+                dev_priv->panel_fixed_mode = intel_crtc_mode_get(dev, crtc);
+                if (dev_priv->panel_fixed_mode) {
+                        dev_priv->panel_fixed_mode->type |=
+                                DRM_MODE_TYPE_PREFERRED;
+                        goto out; /* FIXME: check for quirks */
+                }
+        }
+
+        /* If we still don't have a mode after all that, give up. */
+        if (!dev_priv->panel_fixed_mode)
+                goto failed;
+
+        /* FIXME: detect aopen & mac mini type stuff automatically? */
+        /*
+         * Blacklist machines with BIOSes that list an LVDS panel without
+         * actually having one.
+         */
+        if (IS_I945GM(dev)) {
+                /* aopen mini pc */
+                if (dev->pdev->subsystem_vendor == 0xa0a0)
+                        goto failed;
+
+                if ((dev->pdev->subsystem_vendor == 0x8086) &&
+                    (dev->pdev->subsystem_device == 0x7270)) {
+                        /* It's a Mac Mini or Macbook Pro.
+                         *
+                         * Apple hardware is out to get us.  The macbook pro
+                         * has a real LVDS panel, but the mac mini does not,
+                         * and they have the same device IDs.  We'll
+                         * distinguish by panel size, on the assumption
+                         * that Apple isn't about to make any machines with an
+                         * 800x600 display.
+                         */
+
+                        if (dev_priv->panel_fixed_mode != NULL &&
+                            dev_priv->panel_fixed_mode->hdisplay == 800 &&
+                            dev_priv->panel_fixed_mode->vdisplay == 600) {
+                                DRM_DEBUG("Suspected Mac Mini, ignoring the LVDS\n");
+                                goto failed;
+                        }
+                }
+        }
+
+
+out:
+        drm_sysfs_connector_add(connector);
+        return;
+
+failed:
+        DRM_DEBUG("No LVDS modes found, disabling.\n");
+        if (intel_output->ddc_bus)
+                intel_i2c_destroy(intel_output->ddc_bus);
+        drm_connector_cleanup(connector);
+        kfree(connector);
+}