gma500: Add support for Cedarview

Again this is similar but has some differences so we have a set of plug in
support. This does make the driver bigger than is needed in some respects
but the tradeoff for maintainability is huge.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 721 insertions, 0 deletions

diff --git a/drivers/gpu/drm/gma500/cdv_intel_lvds.c b/drivers/gpu/drm/gma500/cdv_intel_lvds.c
new file mode 100644
index 000000000000..988b2d0acf43
--- /dev/null
+++ b/drivers/gpu/drm/gma500/cdv_intel_lvds.c
@@ -0,0 +1,721 @@
+/*
+ * Copyright © 2006-2011 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Authors:
+ *      Eric Anholt <eric@anholt.net>
+ *      Dave Airlie <airlied@linux.ie>
+ *      Jesse Barnes <jesse.barnes@intel.com>
+ */
+
+#include <linux/i2c.h>
+#include <linux/dmi.h>
+#include <drm/drmP.h>
+
+#include "intel_bios.h"
+#include "psb_drv.h"
+#include "psb_intel_drv.h"
+#include "psb_intel_reg.h"
+#include "power.h"
+#include <linux/pm_runtime.h>
+#include "cdv_device.h"
+
+/**
+ * LVDS I2C backlight control macros
+ */
+#define BRIGHTNESS_MAX_LEVEL 100
+#define BRIGHTNESS_MASK 0xFF
+#define BLC_I2C_TYPE    0x01
+#define BLC_PWM_TYPT    0x02
+
+#define BLC_POLARITY_NORMAL 0
+#define BLC_POLARITY_INVERSE 1
+
+#define PSB_BLC_MAX_PWM_REG_FREQ       (0xFFFE)
+#define PSB_BLC_MIN_PWM_REG_FREQ        (0x2)
+#define PSB_BLC_PWM_PRECISION_FACTOR    (10)
+#define PSB_BACKLIGHT_PWM_CTL_SHIFT     (16)
+#define PSB_BACKLIGHT_PWM_POLARITY_BIT_CLEAR (0xFFFE)
+
+struct cdv_intel_lvds_priv {
+        /**
+         * Saved LVDO output states
+         */
+        uint32_t savePP_ON;
+        uint32_t savePP_OFF;
+        uint32_t saveLVDS;
+        uint32_t savePP_CONTROL;
+        uint32_t savePP_CYCLE;
+        uint32_t savePFIT_CONTROL;
+        uint32_t savePFIT_PGM_RATIOS;
+        uint32_t saveBLC_PWM_CTL;
+};
+
+/*
+ * Returns the maximum level of the backlight duty cycle field.
+ */
+static u32 cdv_intel_lvds_get_max_backlight(struct drm_device *dev)
+{
+        struct drm_psb_private *dev_priv = dev->dev_private;
+        u32 retval;
+
+        if (gma_power_begin(dev, false)) {
+                retval = ((REG_READ(BLC_PWM_CTL) &
+                          BACKLIGHT_MODULATION_FREQ_MASK) >>
+                          BACKLIGHT_MODULATION_FREQ_SHIFT) * 2;
+
+                gma_power_end(dev);
+        } else
+                retval = ((dev_priv->saveBLC_PWM_CTL &
+                          BACKLIGHT_MODULATION_FREQ_MASK) >>
+                          BACKLIGHT_MODULATION_FREQ_SHIFT) * 2;
+
+        return retval;
+}
+
+/*
+ * Set LVDS backlight level by I2C command
+ */
+static int cdv_lvds_i2c_set_brightness(struct drm_device *dev,
+                                        unsigned int level)
+{
+        struct drm_psb_private *dev_priv = dev->dev_private;
+        struct psb_intel_i2c_chan *lvds_i2c_bus = dev_priv->lvds_i2c_bus;
+        u8 out_buf[2];
+        unsigned int blc_i2c_brightness;
+
+        struct i2c_msg msgs[] = {
+                {
+                        .addr = lvds_i2c_bus->slave_addr,
+                        .flags = 0,
+                        .len = 2,
+                        .buf = out_buf,
+                }
+        };
+
+        blc_i2c_brightness = BRIGHTNESS_MASK & ((unsigned int)level *
+                             BRIGHTNESS_MASK /
+                             BRIGHTNESS_MAX_LEVEL);
+
+        if (dev_priv->lvds_bl->pol == BLC_POLARITY_INVERSE)
+                blc_i2c_brightness = BRIGHTNESS_MASK - blc_i2c_brightness;
+
+        out_buf[0] = dev_priv->lvds_bl->brightnesscmd;
+        out_buf[1] = (u8)blc_i2c_brightness;
+
+        if (i2c_transfer(&lvds_i2c_bus->adapter, msgs, 1) == 1)
+                return 0;
+
+        DRM_ERROR("I2C transfer error\n");
+        return -1;
+}
+
+
+static int cdv_lvds_pwm_set_brightness(struct drm_device *dev, int level)
+{
+        struct drm_psb_private *dev_priv = dev->dev_private;
+
+        u32 max_pwm_blc;
+        u32 blc_pwm_duty_cycle;
+
+        max_pwm_blc = cdv_intel_lvds_get_max_backlight(dev);
+
+        /*BLC_PWM_CTL Should be initiated while backlight device init*/
+        BUG_ON((max_pwm_blc & PSB_BLC_MAX_PWM_REG_FREQ) == 0);
+
+        blc_pwm_duty_cycle = level * max_pwm_blc / BRIGHTNESS_MAX_LEVEL;
+
+        if (dev_priv->lvds_bl->pol == BLC_POLARITY_INVERSE)
+                blc_pwm_duty_cycle = max_pwm_blc - blc_pwm_duty_cycle;
+
+        blc_pwm_duty_cycle &= PSB_BACKLIGHT_PWM_POLARITY_BIT_CLEAR;
+        REG_WRITE(BLC_PWM_CTL,
+                  (max_pwm_blc << PSB_BACKLIGHT_PWM_CTL_SHIFT) |
+                  (blc_pwm_duty_cycle));
+
+        return 0;
+}
+
+/*
+ * Set LVDS backlight level either by I2C or PWM
+ */
+void cdv_intel_lvds_set_brightness(struct drm_device *dev, int level)
+{
+        struct drm_psb_private *dev_priv = dev->dev_private;
+
+        if (!dev_priv->lvds_bl) {
+                DRM_ERROR("NO LVDS Backlight Info\n");
+                return;
+        }
+
+        if (dev_priv->lvds_bl->type == BLC_I2C_TYPE)
+                cdv_lvds_i2c_set_brightness(dev, level);
+        else
+                cdv_lvds_pwm_set_brightness(dev, level);
+}
+
+/**
+ * Sets the backlight level.
+ *
+ * level backlight level, from 0 to cdv_intel_lvds_get_max_backlight().
+ */
+static void cdv_intel_lvds_set_backlight(struct drm_device *dev, int level)
+{
+        struct drm_psb_private *dev_priv = dev->dev_private;
+        u32 blc_pwm_ctl;
+
+        if (gma_power_begin(dev, false)) {
+                blc_pwm_ctl =
+                        REG_READ(BLC_PWM_CTL) & ~BACKLIGHT_DUTY_CYCLE_MASK;
+                REG_WRITE(BLC_PWM_CTL,
+                                (blc_pwm_ctl |
+                                (level << BACKLIGHT_DUTY_CYCLE_SHIFT)));
+                gma_power_end(dev);
+        } else {
+                blc_pwm_ctl = dev_priv->saveBLC_PWM_CTL &
+                                ~BACKLIGHT_DUTY_CYCLE_MASK;
+                dev_priv->saveBLC_PWM_CTL = (blc_pwm_ctl |
+                                        (level << BACKLIGHT_DUTY_CYCLE_SHIFT));
+        }
+}
+
+/**
+ * Sets the power state for the panel.
+ */
+static void cdv_intel_lvds_set_power(struct drm_device *dev,
+                                 struct psb_intel_output *output, bool on)
+{
+        u32 pp_status;
+
+        if (!gma_power_begin(dev, true))
+                return;
+
+        if (on) {
+                REG_WRITE(PP_CONTROL, REG_READ(PP_CONTROL) |
+                          POWER_TARGET_ON);
+                do {
+                        pp_status = REG_READ(PP_STATUS);
+                } while ((pp_status & PP_ON) == 0);
+
+                cdv_intel_lvds_set_backlight(dev,
+                                         output->
+                                         mode_dev->backlight_duty_cycle);
+        } else {
+                cdv_intel_lvds_set_backlight(dev, 0);
+
+                REG_WRITE(PP_CONTROL, REG_READ(PP_CONTROL) &
+                          ~POWER_TARGET_ON);
+                do {
+                        pp_status = REG_READ(PP_STATUS);
+                } while (pp_status & PP_ON);
+        }
+        gma_power_end(dev);
+}
+
+static void cdv_intel_lvds_encoder_dpms(struct drm_encoder *encoder, int mode)
+{
+        struct drm_device *dev = encoder->dev;
+        struct psb_intel_output *output = enc_to_psb_intel_output(encoder);
+        if (mode == DRM_MODE_DPMS_ON)
+                cdv_intel_lvds_set_power(dev, output, true);
+        else
+                cdv_intel_lvds_set_power(dev, output, false);
+        /* XXX: We never power down the LVDS pairs. */
+}
+
+static void cdv_intel_lvds_save(struct drm_connector *connector)
+{
+}
+
+static void cdv_intel_lvds_restore(struct drm_connector *connector)
+{
+}
+
+int cdv_intel_lvds_mode_valid(struct drm_connector *connector,
+                                 struct drm_display_mode *mode)
+{
+        struct psb_intel_output *psb_intel_output =
+                                to_psb_intel_output(connector);
+        struct drm_display_mode *fixed_mode =
+            psb_intel_output->mode_dev->panel_fixed_mode;
+
+        /* just in case */
+        if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
+                return MODE_NO_DBLESCAN;
+
+        /* just in case */
+        if (mode->flags & DRM_MODE_FLAG_INTERLACE)
+                return MODE_NO_INTERLACE;
+
+        if (fixed_mode) {
+                if (mode->hdisplay > fixed_mode->hdisplay)
+                        return MODE_PANEL;
+                if (mode->vdisplay > fixed_mode->vdisplay)
+                        return MODE_PANEL;
+        }
+        return MODE_OK;
+}
+
+bool cdv_intel_lvds_mode_fixup(struct drm_encoder *encoder,
+                                  struct drm_display_mode *mode,
+                                  struct drm_display_mode *adjusted_mode)
+{
+        struct psb_intel_mode_device *mode_dev =
+            enc_to_psb_intel_output(encoder)->mode_dev;
+        struct drm_device *dev = encoder->dev;
+        struct drm_encoder *tmp_encoder;
+        struct drm_display_mode *panel_fixed_mode = mode_dev->panel_fixed_mode;
+
+        /* 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 (panel_fixed_mode != NULL) {
+                adjusted_mode->hdisplay = panel_fixed_mode->hdisplay;
+                adjusted_mode->hsync_start = panel_fixed_mode->hsync_start;
+                adjusted_mode->hsync_end = panel_fixed_mode->hsync_end;
+                adjusted_mode->htotal = panel_fixed_mode->htotal;
+                adjusted_mode->vdisplay = panel_fixed_mode->vdisplay;
+                adjusted_mode->vsync_start = panel_fixed_mode->vsync_start;
+                adjusted_mode->vsync_end = panel_fixed_mode->vsync_end;
+                adjusted_mode->vtotal = panel_fixed_mode->vtotal;
+                adjusted_mode->clock = 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 cdv_intel_lvds_prepare(struct drm_encoder *encoder)
+{
+        struct drm_device *dev = encoder->dev;
+        struct psb_intel_output *output = enc_to_psb_intel_output(encoder);
+        struct psb_intel_mode_device *mode_dev = output->mode_dev;
+
+        if (!gma_power_begin(dev, true))
+                return;
+
+        mode_dev->saveBLC_PWM_CTL = REG_READ(BLC_PWM_CTL);
+        mode_dev->backlight_duty_cycle = (mode_dev->saveBLC_PWM_CTL &
+                                          BACKLIGHT_DUTY_CYCLE_MASK);
+
+        cdv_intel_lvds_set_power(dev, output, false);
+
+        gma_power_end(dev);
+}
+
+static void cdv_intel_lvds_commit(struct drm_encoder *encoder)
+{
+        struct drm_device *dev = encoder->dev;
+        struct psb_intel_output *output = enc_to_psb_intel_output(encoder);
+        struct psb_intel_mode_device *mode_dev = output->mode_dev;
+
+        if (mode_dev->backlight_duty_cycle == 0)
+                mode_dev->backlight_duty_cycle =
+                    cdv_intel_lvds_get_max_backlight(dev);
+
+        cdv_intel_lvds_set_power(dev, output, true);
+}
+
+static void cdv_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_psb_private *dev_priv = dev->dev_private;
+        u32 pfit_control;
+
+        /*
+         * The LVDS pin pair will already have been turned on in the
+         * cdv_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 (dev_priv->lvds_dither)
+                pfit_control |= PANEL_8TO6_DITHER_ENABLE;
+
+        REG_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 cdv_intel_lvds_detect(
+                                struct drm_connector *connector, bool force)
+{
+        return connector_status_connected;
+}
+
+/**
+ * Return the list of DDC modes if available, or the BIOS fixed mode otherwise.
+ */
+static int cdv_intel_lvds_get_modes(struct drm_connector *connector)
+{
+        struct drm_device *dev = connector->dev;
+        struct psb_intel_output *psb_intel_output =
+                                        to_psb_intel_output(connector);
+        struct psb_intel_mode_device *mode_dev =
+                                        psb_intel_output->mode_dev;
+        int ret;
+
+        ret = psb_intel_ddc_get_modes(psb_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 (mode_dev->panel_fixed_mode != NULL) {
+                struct drm_display_mode *mode =
+                    drm_mode_duplicate(dev, mode_dev->panel_fixed_mode);
+                drm_mode_probed_add(connector, mode);
+                return 1;
+        }
+
+        return 0;
+}
+
+/**
+ * cdv_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.
+ */
+void cdv_intel_lvds_destroy(struct drm_connector *connector)
+{
+        struct psb_intel_output *psb_intel_output =
+                                        to_psb_intel_output(connector);
+
+        if (psb_intel_output->ddc_bus)
+                psb_intel_i2c_destroy(psb_intel_output->ddc_bus);
+        drm_sysfs_connector_remove(connector);
+        drm_connector_cleanup(connector);
+        kfree(connector);
+}
+
+int cdv_intel_lvds_set_property(struct drm_connector *connector,
+                                       struct drm_property *property,
+                                       uint64_t value)
+{
+        struct drm_encoder *encoder = connector->encoder;
+
+        if (!strcmp(property->name, "scaling mode") && encoder) {
+                struct psb_intel_crtc *crtc =
+                                        to_psb_intel_crtc(encoder->crtc);
+                uint64_t curValue;
+
+                if (!crtc)
+                        return -1;
+
+                switch (value) {
+                case DRM_MODE_SCALE_FULLSCREEN:
+                        break;
+                case DRM_MODE_SCALE_NO_SCALE:
+                        break;
+                case DRM_MODE_SCALE_ASPECT:
+                        break;
+                default:
+                        return -1;
+                }
+
+                if (drm_connector_property_get_value(connector,
+                                                     property,
+                                                     &curValue))
+                        return -1;
+
+                if (curValue == value)
+                        return 0;
+
+                if (drm_connector_property_set_value(connector,
+                                                        property,
+                                                        value))
+                        return -1;
+
+                if (crtc->saved_mode.hdisplay != 0 &&
+                    crtc->saved_mode.vdisplay != 0) {
+                        if (!drm_crtc_helper_set_mode(encoder->crtc,
+                                                      &crtc->saved_mode,
+                                                      encoder->crtc->x,
+                                                      encoder->crtc->y,
+                                                      encoder->crtc->fb))
+                                return -1;
+                }
+        } else if (!strcmp(property->name, "backlight") && encoder) {
+                if (drm_connector_property_set_value(connector,
+                                                        property,
+                                                        value))
+                        return -1;
+                else {
+#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
+                        struct drm_psb_private *dev_priv =
+                                                encoder->dev->dev_private;
+                        struct backlight_device *bd =
+                                                dev_priv->backlight_device;
+                        bd->props.brightness = value;
+                        backlight_update_status(bd);
+#endif
+                }
+        } else if (!strcmp(property->name, "DPMS") && encoder) {
+                struct drm_encoder_helper_funcs *helpers =
+                                        encoder->helper_private;
+                helpers->dpms(encoder, value);
+        }
+        return 0;
+}
+
+static const struct drm_encoder_helper_funcs
+                                        cdv_intel_lvds_helper_funcs = {
+        .dpms = cdv_intel_lvds_encoder_dpms,
+        .mode_fixup = cdv_intel_lvds_mode_fixup,
+        .prepare = cdv_intel_lvds_prepare,
+        .mode_set = cdv_intel_lvds_mode_set,
+        .commit = cdv_intel_lvds_commit,
+};
+
+static const struct drm_connector_helper_funcs
+                                cdv_intel_lvds_connector_helper_funcs = {
+        .get_modes = cdv_intel_lvds_get_modes,
+        .mode_valid = cdv_intel_lvds_mode_valid,
+        .best_encoder = psb_intel_best_encoder,
+};
+
+static const struct drm_connector_funcs cdv_intel_lvds_connector_funcs = {
+        .dpms = drm_helper_connector_dpms,
+        .save = cdv_intel_lvds_save,
+        .restore = cdv_intel_lvds_restore,
+        .detect = cdv_intel_lvds_detect,
+        .fill_modes = drm_helper_probe_single_connector_modes,
+        .set_property = cdv_intel_lvds_set_property,
+        .destroy = cdv_intel_lvds_destroy,
+};
+
+
+static void cdv_intel_lvds_enc_destroy(struct drm_encoder *encoder)
+{
+        drm_encoder_cleanup(encoder);
+}
+
+const struct drm_encoder_funcs cdv_intel_lvds_enc_funcs = {
+        .destroy = cdv_intel_lvds_enc_destroy,
+};
+
+/**
+ * cdv_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 cdv_intel_lvds_init(struct drm_device *dev,
+                     struct psb_intel_mode_device *mode_dev)
+{
+        struct psb_intel_output *psb_intel_output;
+        struct cdv_intel_lvds_priv *lvds_priv;
+        struct drm_connector *connector;
+        struct drm_encoder *encoder;
+        struct drm_display_mode *scan;
+        struct drm_crtc *crtc;
+        struct drm_psb_private *dev_priv = dev->dev_private;
+        u32 lvds;
+        int pipe;
+
+        psb_intel_output = kzalloc(sizeof(struct psb_intel_output) +
+                        sizeof(struct cdv_intel_lvds_priv), GFP_KERNEL);
+        if (!psb_intel_output)
+                return;
+
+        lvds_priv = (struct cdv_intel_lvds_priv *)(psb_intel_output + 1);
+
+        psb_intel_output->dev_priv = lvds_priv;
+
+        psb_intel_output->mode_dev = mode_dev;
+        connector = &psb_intel_output->base;
+        encoder = &psb_intel_output->enc;
+
+
+        drm_connector_init(dev, &psb_intel_output->base,
+                           &cdv_intel_lvds_connector_funcs,
+                           DRM_MODE_CONNECTOR_LVDS);
+
+        drm_encoder_init(dev, &psb_intel_output->enc,
+                         &cdv_intel_lvds_enc_funcs,
+                         DRM_MODE_ENCODER_LVDS);
+
+
+        drm_mode_connector_attach_encoder(&psb_intel_output->base,
+                                          &psb_intel_output->enc);
+        psb_intel_output->type = INTEL_OUTPUT_LVDS;
+
+        drm_encoder_helper_add(encoder, &cdv_intel_lvds_helper_funcs);
+        drm_connector_helper_add(connector,
+                                 &cdv_intel_lvds_connector_helper_funcs);
+        connector->display_info.subpixel_order = SubPixelHorizontalRGB;
+        connector->interlace_allowed = false;
+        connector->doublescan_allowed = false;
+
+        /*Attach connector properties*/
+        drm_connector_attach_property(connector,
+                                      dev->mode_config.scaling_mode_property,
+                                      DRM_MODE_SCALE_FULLSCREEN);
+        drm_connector_attach_property(connector,
+                                      dev_priv->backlight_property,
+                                      BRIGHTNESS_MAX_LEVEL);
+
+        /**
+         * Set up I2C bus
+         * FIXME: distroy i2c_bus when exit
+         */
+        psb_intel_output->i2c_bus = psb_intel_i2c_create(dev,
+                                                         GPIOB,
+                                                         "LVDSBLC_B");
+        if (!psb_intel_output->i2c_bus) {
+                dev_printk(KERN_ERR,
+                        &dev->pdev->dev, "I2C bus registration failed.\n");
+                goto failed_blc_i2c;
+        }
+        psb_intel_output->i2c_bus->slave_addr = 0x2C;
+        dev_priv->lvds_i2c_bus =  psb_intel_output->i2c_bus;
+
+        /*
+         * 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. */
+        psb_intel_output->ddc_bus = psb_intel_i2c_create(dev,
+                                                         GPIOC,
+                                                         "LVDSDDC_C");
+        if (!psb_intel_output->ddc_bus) {
+                dev_printk(KERN_ERR, &dev->pdev->dev,
+                           "DDC bus registration " "failed.\n");
+                goto failed_ddc;
+        }
+
+        /*
+         * Attempt to get the fixed panel mode from DDC.  Assume that the
+         * preferred mode is the right one.
+         */
+        psb_intel_ddc_get_modes(psb_intel_output);
+        list_for_each_entry(scan, &connector->probed_modes, head) {
+                if (scan->type & DRM_MODE_TYPE_PREFERRED) {
+                        mode_dev->panel_fixed_mode =
+                            drm_mode_duplicate(dev, scan);
+                        goto out;       /* FIXME: check for quirks */
+                }
+        }
+
+        /* Failed to get EDID, what about VBT? do we need this?*/
+        if (dev_priv->lfp_lvds_vbt_mode) {
+                mode_dev->panel_fixed_mode =
+                        drm_mode_duplicate(dev, dev_priv->lfp_lvds_vbt_mode);
+                if (mode_dev->panel_fixed_mode) {
+                        mode_dev->panel_fixed_mode->type |=
+                                DRM_MODE_TYPE_PREFERRED;
+                        goto out;       /* FIXME: check for quirks */
+                }
+        }
+        /*
+         * 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 = REG_READ(LVDS);
+        pipe = (lvds & LVDS_PIPEB_SELECT) ? 1 : 0;
+        crtc = psb_intel_get_crtc_from_pipe(dev, pipe);
+
+        if (crtc && (lvds & LVDS_PORT_EN)) {
+                mode_dev->panel_fixed_mode =
+                    cdv_intel_crtc_mode_get(dev, crtc);
+                if (mode_dev->panel_fixed_mode) {
+                        mode_dev->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 (!mode_dev->panel_fixed_mode) {
+                DRM_DEBUG
+                        ("Found no modes on the lvds, ignoring the LVDS\n");
+                goto failed_find;
+        }
+
+out:
+        drm_sysfs_connector_add(connector);
+        return;
+
+failed_find:
+        printk(KERN_ERR "Failed find\n");
+        if (psb_intel_output->ddc_bus)
+                psb_intel_i2c_destroy(psb_intel_output->ddc_bus);
+failed_ddc:
+        printk(KERN_ERR "Failed DDC\n");
+        if (psb_intel_output->i2c_bus)
+                psb_intel_i2c_destroy(psb_intel_output->i2c_bus);
+failed_blc_i2c:
+        printk(KERN_ERR "Failed BLC\n");
+        drm_encoder_cleanup(encoder);
+        drm_connector_cleanup(connector);
+        kfree(connector);
+}