/*
 * 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>
 *      Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
 */

#include <drm/drmP.h>
#include "gma_display.h"
#include "psb_intel_drv.h"
#include "psb_intel_reg.h"
#include "psb_drv.h"
#include "framebuffer.h"

/**
 * Returns whether any output on the specified pipe is of the specified type
 */
bool gma_pipe_has_type(struct drm_crtc *crtc, int type)
{
        struct drm_device *dev = crtc->dev;
        struct drm_mode_config *mode_config = &dev->mode_config;
        struct drm_connector *l_entry;

        list_for_each_entry(l_entry, &mode_config->connector_list, head) {
                if (l_entry->encoder && l_entry->encoder->crtc == crtc) {
                        struct gma_encoder *gma_encoder =
                                                gma_attached_encoder(l_entry);
                        if (gma_encoder->type == type)
                                return true;
                }
        }

        return false;
}

void gma_wait_for_vblank(struct drm_device *dev)
{
        /* Wait for 20ms, i.e. one cycle at 50hz. */
        mdelay(20);
}

int gma_pipe_set_base(struct drm_crtc *crtc, int x, int y,
                      struct drm_framebuffer *old_fb)
{
        struct drm_device *dev = crtc->dev;
        struct drm_psb_private *dev_priv = dev->dev_private;
        struct gma_crtc *gma_crtc = to_gma_crtc(crtc);
        struct drm_framebuffer *fb = crtc->primary->fb;
        struct psb_framebuffer *psbfb = to_psb_fb(fb);
        int pipe = gma_crtc->pipe;
        const struct psb_offset *map = &dev_priv->regmap[pipe];
        unsigned long start, offset;
        u32 dspcntr;
        int ret = 0;

        if (!gma_power_begin(dev, true))
                return 0;

        /* no fb bound */
        if (!fb) {
                dev_err(dev->dev, "No FB bound\n");
                goto gma_pipe_cleaner;
        }

        /* We are displaying this buffer, make sure it is actually loaded
           into the GTT */
        ret = psb_gtt_pin(psbfb->gtt);
        if (ret < 0)
                goto gma_pipe_set_base_exit;
        start = psbfb->gtt->offset;
        offset = y * fb->pitches[0] + x * fb->format->cpp[0];

        REG_WRITE(map->stride, fb->pitches[0]);

        dspcntr = REG_READ(map->cntr);
        dspcntr &= ~DISPPLANE_PIXFORMAT_MASK;

        switch (fb->format->cpp[0] * 8) {
        case 8:
                dspcntr |= DISPPLANE_8BPP;
                break;
        case 16:
                if (fb->format->depth == 15)
                        dspcntr |= DISPPLANE_15_16BPP;
                else
                        dspcntr |= DISPPLANE_16BPP;
                break;
        case 24:
        case 32:
                dspcntr |= DISPPLANE_32BPP_NO_ALPHA;
                break;
        default:
                dev_err(dev->dev, "Unknown color depth\n");
                ret = -EINVAL;
                goto gma_pipe_set_base_exit;
        }
        REG_WRITE(map->cntr, dspcntr);

        dev_dbg(dev->dev,
                "Writing base %08lX %08lX %d %d\n", start, offset, x, y);

        /* FIXME: Investigate whether this really is the base for psb and why
                  the linear offset is named base for the other chips. map->surf
                  should be the base and map->linoff the offset for all chips */
        if (IS_PSB(dev)) {
                REG_WRITE(map->base, offset + start);
                REG_READ(map->base);
        } else {
                REG_WRITE(map->base, offset);
                REG_READ(map->base);
                REG_WRITE(map->surf, start);
                REG_READ(map->surf);
        }

gma_pipe_cleaner:
        /* If there was a previous display we can now unpin it */
        if (old_fb)
                psb_gtt_unpin(to_psb_fb(old_fb)->gtt);

gma_pipe_set_base_exit:
        gma_power_end(dev);
        return ret;
}

/* Loads the palette/gamma unit for the CRTC with the prepared values */
void gma_crtc_load_lut(struct drm_crtc *crtc)
{
        struct drm_device *dev = crtc->dev;
        struct drm_psb_private *dev_priv = dev->dev_private;
        struct gma_crtc *gma_crtc = to_gma_crtc(crtc);
        const struct psb_offset *map = &dev_priv->regmap[gma_crtc->pipe];
        int palreg = map->palette;
        u16 *r, *g, *b;
        int i;

        /* The clocks have to be on to load the palette. */
        if (!crtc->enabled)
                return;

        r = crtc->gamma_store;
        g = r + crtc->gamma_size;
        b = g + crtc->gamma_size;

        if (gma_power_begin(dev, false)) {
                for (i = 0; i < 256; i++) {
                        REG_WRITE(palreg + 4 * i,
                                  (((*r++ >> 8) + gma_crtc->lut_adj[i]) << 16) |
                                  (((*g++ >> 8) + gma_crtc->lut_adj[i]) << 8) |
                                  ((*b++ >> 8) + gma_crtc->lut_adj[i]));
                }
                gma_power_end(dev);
        } else {
                for (i = 0; i < 256; i++) {
                        /* FIXME: Why pipe[0] and not pipe[..._crtc->pipe]? */
                        dev_priv->regs.pipe[0].palette[i] =
                                (((*r++ >> 8) + gma_crtc->lut_adj[i]) << 16) |
                                (((*g++ >> 8) + gma_crtc->lut_adj[i]) << 8) |
                                ((*b++ >> 8) + gma_crtc->lut_adj[i]);
                }

        }
}

int gma_crtc_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green, u16 *blue,
                       u32 size,
                       struct drm_modeset_acquire_ctx *ctx)
{
        gma_crtc_load_lut(crtc);

        return 0;
}

/**
 * Sets the power management mode of the pipe and plane.
 *
 * This code should probably grow support for turning the cursor off and back
 * on appropriately at the same time as we're turning the pipe off/on.
 */
void gma_crtc_dpms(struct drm_crtc *crtc, int mode)
{
        struct drm_device *dev = crtc->dev;
        struct drm_psb_private *dev_priv = dev->dev_private;
        struct gma_crtc *gma_crtc = to_gma_crtc(crtc);
        int pipe = gma_crtc->pipe;
        const struct psb_offset *map = &dev_priv->regmap[pipe];
        u32 temp;

        /* XXX: When our outputs are all unaware of DPMS modes other than off
         * and on, we should map those modes to DRM_MODE_DPMS_OFF in the CRTC.
         */

        if (IS_CDV(dev))
                dev_priv->ops->disable_sr(dev);

        switch (mode) {
        case DRM_MODE_DPMS_ON:
        case DRM_MODE_DPMS_STANDBY:
        case DRM_MODE_DPMS_SUSPEND:
                if (gma_crtc->active)
                        break;

                gma_crtc->active = true;

                /* Enable the DPLL */
                temp = REG_READ(map->dpll);
                if ((temp & DPLL_VCO_ENABLE) == 0) {
                        REG_WRITE(map->dpll, temp);
                        REG_READ(map->dpll);
                        /* Wait for the clocks to stabilize. */
                        udelay(150);
                        REG_WRITE(map->dpll, temp | DPLL_VCO_ENABLE);
                        REG_READ(map->dpll);
                        /* Wait for the clocks to stabilize. */
                        udelay(150);
                        REG_WRITE(map->dpll, temp | DPLL_VCO_ENABLE);
                        REG_READ(map->dpll);
                        /* Wait for the clocks to stabilize. */
                        udelay(150);
                }

                /* Enable the plane */
                temp = REG_READ(map->cntr);
                if ((temp & DISPLAY_PLANE_ENABLE) == 0) {
                        REG_WRITE(map->cntr,
                                  temp | DISPLAY_PLANE_ENABLE);
                        /* Flush the plane changes */
                        REG_WRITE(map->base, REG_READ(map->base));
                }

                udelay(150);

                /* Enable the pipe */
                temp = REG_READ(map->conf);
                if ((temp & PIPEACONF_ENABLE) == 0)
                        REG_WRITE(map->conf, temp | PIPEACONF_ENABLE);

                temp = REG_READ(map->status);
                temp &= ~(0xFFFF);
                temp |= PIPE_FIFO_UNDERRUN;
                REG_WRITE(map->status, temp);
                REG_READ(map->status);

                gma_crtc_load_lut(crtc);

                /* Give the overlay scaler a chance to enable
                 * if it's on this pipe */
                /* psb_intel_crtc_dpms_video(crtc, true); TODO */
                break;
        case DRM_MODE_DPMS_OFF:
                if (!gma_crtc->active)
                        break;

                gma_crtc->active = false;

                /* Give the overlay scaler a chance to disable
                 * if it's on this pipe */
                /* psb_intel_crtc_dpms_video(crtc, FALSE); TODO */

                /* Disable the VGA plane that we never use */
                REG_WRITE(VGACNTRL, VGA_DISP_DISABLE);

                /* Turn off vblank interrupts */
                drm_crtc_vblank_off(crtc);

                /* Wait for vblank for the disable to take effect */
                gma_wait_for_vblank(dev);

                /* Disable plane */
                temp = REG_READ(map->cntr);
                if ((temp & DISPLAY_PLANE_ENABLE) != 0) {
                        REG_WRITE(map->cntr,
                                  temp & ~DISPLAY_PLANE_ENABLE);
                        /* Flush the plane changes */
                        REG_WRITE(map->base, REG_READ(map->base));
                        REG_READ(map->base);
                }

                /* Disable pipe */
                temp = REG_READ(map->conf);
                if ((temp & PIPEACONF_ENABLE) != 0) {
                        REG_WRITE(map->conf, temp & ~PIPEACONF_ENABLE);
                        REG_READ(map->conf);
                }

                /* Wait for vblank for the disable to take effect. */
                gma_wait_for_vblank(dev);

                udelay(150);

                /* Disable DPLL */
                temp = REG_READ(map->dpll);
                if ((temp & DPLL_VCO_ENABLE) != 0) {
                        REG_WRITE(map->dpll, temp & ~DPLL_VCO_ENABLE);
                        REG_READ(map->dpll);
                }

                /* Wait for the clocks to turn off. */
                udelay(150);
                break;
        }

        if (IS_CDV(dev))
                dev_priv->ops->update_wm(dev, crtc);

        /* Set FIFO watermarks */
        REG_WRITE(DSPARB, 0x3F3E);
}

int gma_crtc_cursor_set(struct drm_crtc *crtc,
                        struct drm_file *file_priv,
                        uint32_t handle,
                        uint32_t width, uint32_t height)
{
        struct drm_device *dev = crtc->dev;
        struct drm_psb_private *dev_priv = dev->dev_private;
        struct gma_crtc *gma_crtc = to_gma_crtc(crtc);
        int pipe = gma_crtc->pipe;
        uint32_t control = (pipe == 0) ? CURACNTR : CURBCNTR;
        uint32_t base = (pipe == 0) ? CURABASE : CURBBASE;
        uint32_t temp;
        size_t addr = 0;
        struct gtt_range *gt;
        struct gtt_range *cursor_gt = gma_crtc->cursor_gt;
        struct drm_gem_object *obj;
        void *tmp_dst, *tmp_src;
        int ret = 0, i, cursor_pages;

        /* If we didn't get a handle then turn the cursor off */
        if (!handle) {
                temp = CURSOR_MODE_DISABLE;
                if (gma_power_begin(dev, false)) {
                        REG_WRITE(control, temp);
                        REG_WRITE(base, 0);
                        gma_power_end(dev);
                }

                /* Unpin the old GEM object */
                if (gma_crtc->cursor_obj) {
                        gt = container_of(gma_crtc->cursor_obj,
                                          struct gtt_range, gem);
                        psb_gtt_unpin(gt);
                        drm_gem_object_unreference_unlocked(gma_crtc->cursor_obj);
                        gma_crtc->cursor_obj = NULL;
                }
                return 0;
        }

        /* Currently we only support 64x64 cursors */
        if (width != 64 || height != 64) {
                dev_dbg(dev->dev, "We currently only support 64x64 cursors\n");
                return -EINVAL;
        }

        obj = drm_gem_object_lookup(file_priv, handle);
        if (!obj) {
                ret = -ENOENT;
                goto unlock;
        }

        if (obj->size < width * height * 4) {
                dev_dbg(dev->dev, "Buffer is too small\n");
                ret = -ENOMEM;
                goto unref_cursor;
        }

        gt = container_of(obj, struct gtt_range, gem);

        /* Pin the memory into the GTT */
        ret = psb_gtt_pin(gt);
        if (ret) {
                dev_err(dev->dev, "Can not pin down handle 0x%x\n", handle);
                goto unref_cursor;
        }

        if (dev_priv->ops->cursor_needs_phys) {
                if (cursor_gt == NULL) {
                        dev_err(dev->dev, "No hardware cursor mem available");
                        ret = -ENOMEM;
                        goto unref_cursor;
                }

                /* Prevent overflow */
                if (gt->npage > 4)
                        cursor_pages = 4;
                else
                        cursor_pages = gt->npage;

                /* Copy the cursor to cursor mem */
                tmp_dst = dev_priv->vram_addr + cursor_gt->offset;
                for (i = 0; i < cursor_pages; i++) {
                        tmp_src = kmap(gt->pages[i]);
                        memcpy(tmp_dst, tmp_src, PAGE_SIZE);
                        kunmap(gt->pages[i]);
                        tmp_dst += PAGE_SIZE;
                }

                addr = gma_crtc->cursor_addr;
        } else {
                addr = gt->offset;
                gma_crtc->cursor_addr = addr;
        }

        temp = 0;
        /* set the pipe for the cursor */
        temp |= (pipe << 28);
        temp |= CURSOR_MODE_64_ARGB_AX | MCURSOR_GAMMA_ENABLE;

        if (gma_power_begin(dev, false)) {
                REG_WRITE(control, temp);
                REG_WRITE(base, addr);
                gma_power_end(dev);
        }

        /* unpin the old bo */
        if (gma_crtc->cursor_obj) {
                gt = container_of(gma_crtc->cursor_obj, struct gtt_range, gem);
                psb_gtt_unpin(gt);
                drm_gem_object_unreference_unlocked(gma_crtc->cursor_obj);
        }

        gma_crtc->cursor_obj = obj;
unlock:
        return ret;

unref_cursor:
        drm_gem_object_unreference_unlocked(obj);
        return ret;
}

int gma_crtc_cursor_move(struct drm_crtc *crtc, int x, int y)
{
        struct drm_device *dev = crtc->dev;
        struct gma_crtc *gma_crtc = to_gma_crtc(crtc);
        int pipe = gma_crtc->pipe;
        uint32_t temp = 0;
        uint32_t addr;

        if (x < 0) {
                temp |= (CURSOR_POS_SIGN << CURSOR_X_SHIFT);
                x = -x;
        }
        if (y < 0) {
                temp |= (CURSOR_POS_SIGN << CURSOR_Y_SHIFT);
                y = -y;
        }

        temp |= ((x & CURSOR_POS_MASK) << CURSOR_X_SHIFT);
        temp |= ((y & CURSOR_POS_MASK) << CURSOR_Y_SHIFT);

        addr = gma_crtc->cursor_addr;

        if (gma_power_begin(dev, false)) {
                REG_WRITE((pipe == 0) ? CURAPOS : CURBPOS, temp);
                REG_WRITE((pipe == 0) ? CURABASE : CURBBASE, addr);
                gma_power_end(dev);
        }
        return 0;
}

void gma_crtc_prepare(struct drm_crtc *crtc)
{
        const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
        crtc_funcs->dpms(crtc, DRM_MODE_DPMS_OFF);
}

void gma_crtc_commit(struct drm_crtc *crtc)
{
        const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
        crtc_funcs->dpms(crtc, DRM_MODE_DPMS_ON);
}

void gma_crtc_disable(struct drm_crtc *crtc)
{
        struct gtt_range *gt;
        const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;

        crtc_funcs->dpms(crtc, DRM_MODE_DPMS_OFF);

        if (crtc->primary->fb) {
                gt = to_psb_fb(crtc->primary->fb)->gtt;
                psb_gtt_unpin(gt);
        }
}

void gma_crtc_destroy(struct drm_crtc *crtc)
{
        struct gma_crtc *gma_crtc = to_gma_crtc(crtc);

        kfree(gma_crtc->crtc_state);
        drm_crtc_cleanup(crtc);
        kfree(gma_crtc);
}

int gma_crtc_set_config(struct drm_mode_set *set,
                        struct drm_modeset_acquire_ctx *ctx)
{
        struct drm_device *dev = set->crtc->dev;
        struct drm_psb_private *dev_priv = dev->dev_private;
        int ret;

        if (!dev_priv->rpm_enabled)
                return drm_crtc_helper_set_config(set, ctx);

        pm_runtime_forbid(&dev->pdev->dev);
        ret = drm_crtc_helper_set_config(set, ctx);
        pm_runtime_allow(&dev->pdev->dev);

        return ret;
}

/**
 * Save HW states of given crtc
 */
void gma_crtc_save(struct drm_crtc *crtc)
{
        struct drm_device *dev = crtc->dev;
        struct drm_psb_private *dev_priv = dev->dev_private;
        struct gma_crtc *gma_crtc = to_gma_crtc(crtc);
        struct psb_intel_crtc_state *crtc_state = gma_crtc->crtc_state;
        const struct psb_offset *map = &dev_priv->regmap[gma_crtc->pipe];
        uint32_t palette_reg;
        int i;

        if (!crtc_state) {
                dev_err(dev->dev, "No CRTC state found\n");
                return;
        }

        crtc_state->saveDSPCNTR = REG_READ(map->cntr);
        crtc_state->savePIPECONF = REG_READ(map->conf);
        crtc_state->savePIPESRC = REG_READ(map->src);
        crtc_state->saveFP0 = REG_READ(map->fp0);
        crtc_state->saveFP1 = REG_READ(map->fp1);
        crtc_state->saveDPLL = REG_READ(map->dpll);
        crtc_state->saveHTOTAL = REG_READ(map->htotal);
        crtc_state->saveHBLANK = REG_READ(map->hblank);
        crtc_state->saveHSYNC = REG_READ(map->hsync);
        crtc_state->saveVTOTAL = REG_READ(map->vtotal);
        crtc_state->saveVBLANK = REG_READ(map->vblank);
        crtc_state->saveVSYNC = REG_READ(map->vsync);
        crtc_state->saveDSPSTRIDE = REG_READ(map->stride);

        /* NOTE: DSPSIZE DSPPOS only for psb */
        crtc_state->saveDSPSIZE = REG_READ(map->size);
        crtc_state->saveDSPPOS = REG_READ(map->pos);

        crtc_state->saveDSPBASE = REG_READ(map->base);

        palette_reg = map->palette;
        for (i = 0; i < 256; ++i)
                crtc_state->savePalette[i] = REG_READ(palette_reg + (i << 2));
}

/**
 * Restore HW states of given crtc
 */
void gma_crtc_restore(struct drm_crtc *crtc)
{
        struct drm_device *dev = crtc->dev;
        struct drm_psb_private *dev_priv = dev->dev_private;
        struct gma_crtc *gma_crtc =  to_gma_crtc(crtc);
        struct psb_intel_crtc_state *crtc_state = gma_crtc->crtc_state;
        const struct psb_offset *map = &dev_priv->regmap[gma_crtc->pipe];
        uint32_t palette_reg;
        int i;

        if (!crtc_state) {
                dev_err(dev->dev, "No crtc state\n");
                return;
        }

        if (crtc_state->saveDPLL & DPLL_VCO_ENABLE) {
                REG_WRITE(map->dpll,
                        crtc_state->saveDPLL & ~DPLL_VCO_ENABLE);
                REG_READ(map->dpll);
                udelay(150);
        }

        REG_WRITE(map->fp0, crtc_state->saveFP0);
        REG_READ(map->fp0);

        REG_WRITE(map->fp1, crtc_state->saveFP1);
        REG_READ(map->fp1);

        REG_WRITE(map->dpll, crtc_state->saveDPLL);
        REG_READ(map->dpll);
        udelay(150);

        REG_WRITE(map->htotal, crtc_state->saveHTOTAL);
        REG_WRITE(map->hblank, crtc_state->saveHBLANK);
        REG_WRITE(map->hsync, crtc_state->saveHSYNC);
        REG_WRITE(map->vtotal, crtc_state->saveVTOTAL);
        REG_WRITE(map->vblank, crtc_state->saveVBLANK);
        REG_WRITE(map->vsync, crtc_state->saveVSYNC);
        REG_WRITE(map->stride, crtc_state->saveDSPSTRIDE);

        REG_WRITE(map->size, crtc_state->saveDSPSIZE);
        REG_WRITE(map->pos, crtc_state->saveDSPPOS);

        REG_WRITE(map->src, crtc_state->savePIPESRC);
        REG_WRITE(map->base, crtc_state->saveDSPBASE);
        REG_WRITE(map->conf, crtc_state->savePIPECONF);

        gma_wait_for_vblank(dev);

        REG_WRITE(map->cntr, crtc_state->saveDSPCNTR);
        REG_WRITE(map->base, crtc_state->saveDSPBASE);

        gma_wait_for_vblank(dev);

        palette_reg = map->palette;
        for (i = 0; i < 256; ++i)
                REG_WRITE(palette_reg + (i << 2), crtc_state->savePalette[i]);
}

void gma_encoder_prepare(struct drm_encoder *encoder)
{
        const struct drm_encoder_helper_funcs *encoder_funcs =
            encoder->helper_private;
        /* lvds has its own version of prepare see psb_intel_lvds_prepare */
        encoder_funcs->dpms(encoder, DRM_MODE_DPMS_OFF);
}

void gma_encoder_commit(struct drm_encoder *encoder)
{
        const struct drm_encoder_helper_funcs *encoder_funcs =
            encoder->helper_private;
        /* lvds has its own version of commit see psb_intel_lvds_commit */
        encoder_funcs->dpms(encoder, DRM_MODE_DPMS_ON);
}

void gma_encoder_destroy(struct drm_encoder *encoder)
{
        struct gma_encoder *intel_encoder = to_gma_encoder(encoder);

        drm_encoder_cleanup(encoder);
        kfree(intel_encoder);
}

/* Currently there is only a 1:1 mapping of encoders and connectors */
struct drm_encoder *gma_best_encoder(struct drm_connector *connector)
{
        struct gma_encoder *gma_encoder = gma_attached_encoder(connector);

        return &gma_encoder->base;
}

void gma_connector_attach_encoder(struct gma_connector *connector,
                                  struct gma_encoder *encoder)
{
        connector->encoder = encoder;
        drm_mode_connector_attach_encoder(&connector->base,
                                          &encoder->base);
}

#define GMA_PLL_INVALID(s) { /* DRM_ERROR(s); */ return false; }

bool gma_pll_is_valid(struct drm_crtc *crtc,
                      const struct gma_limit_t *limit,
                      struct gma_clock_t *clock)
{
        if (clock->p1 < limit->p1.min || limit->p1.max < clock->p1)
                GMA_PLL_INVALID("p1 out of range");
        if (clock->p < limit->p.min || limit->p.max < clock->p)
                GMA_PLL_INVALID("p out of range");
        if (clock->m2 < limit->m2.min || limit->m2.max < clock->m2)
                GMA_PLL_INVALID("m2 out of range");
        if (clock->m1 < limit->m1.min || limit->m1.max < clock->m1)
                GMA_PLL_INVALID("m1 out of range");
        /* On CDV m1 is always 0 */
        if (clock->m1 <= clock->m2 && clock->m1 != 0)
                GMA_PLL_INVALID("m1 <= m2 && m1 != 0");
        if (clock->m < limit->m.min || limit->m.max < clock->m)
                GMA_PLL_INVALID("m out of range");
        if (clock->n < limit->n.min || limit->n.max < clock->n)
                GMA_PLL_INVALID("n out of range");
        if (clock->vco < limit->vco.min || limit->vco.max < clock->vco)
                GMA_PLL_INVALID("vco out of range");
        /* XXX: We may need to be checking "Dot clock"
         * depending on the multiplier, connector, etc.,
         * rather than just a single range.
         */
        if (clock->dot < limit->dot.min || limit->dot.max < clock->dot)
                GMA_PLL_INVALID("dot out of range");

        return true;
}

bool gma_find_best_pll(const struct gma_limit_t *limit,
                       struct drm_crtc *crtc, int target, int refclk,
                       struct gma_clock_t *best_clock)
{
        struct drm_device *dev = crtc->dev;
        const struct gma_clock_funcs *clock_funcs =
                                                to_gma_crtc(crtc)->clock_funcs;
        struct gma_clock_t clock;
        int err = target;

        if (gma_pipe_has_type(crtc, INTEL_OUTPUT_LVDS) &&
            (REG_READ(LVDS) & LVDS_PORT_EN) != 0) {
                /*
                 * For LVDS, if the panel is on, just rely on its current
                 * settings for dual-channel.  We haven't figured out how to
                 * reliably set up different single/dual channel state, if we
                 * even can.
                 */
                if ((REG_READ(LVDS) & LVDS_CLKB_POWER_MASK) ==
                    LVDS_CLKB_POWER_UP)
                        clock.p2 = limit->p2.p2_fast;
                else
                        clock.p2 = limit->p2.p2_slow;
        } else {
                if (target < limit->p2.dot_limit)
                        clock.p2 = limit->p2.p2_slow;
                else
                        clock.p2 = limit->p2.p2_fast;
        }

        memset(best_clock, 0, sizeof(*best_clock));

        /* m1 is always 0 on CDV so the outmost loop will run just once */
        for (clock.m1 = limit->m1.min; clock.m1 <= limit->m1.max; clock.m1++) {
                for (clock.m2 = limit->m2.min;
                     (clock.m2 < clock.m1 || clock.m1 == 0) &&
                      clock.m2 <= limit->m2.max; clock.m2++) {
                        for (clock.n = limit->n.min;
                             clock.n <= limit->n.max; clock.n++) {
                                for (clock.p1 = limit->p1.min;
                                     clock.p1 <= limit->p1.max;
                                     clock.p1++) {
                                        int this_err;

                                        clock_funcs->clock(refclk, &clock);

                                        if (!clock_funcs->pll_is_valid(crtc,
                                                                limit, &clock))
                                                continue;

                                        this_err = abs(clock.dot - target);
                                        if (this_err < err) {
                                                *best_clock = clock;
                                                err = this_err;
                                        }
                                }
                        }
                }
        }

        return err != target;
}