drm/nouveau: determine timing crystal freq from straps

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

diff --git a/drivers/gpu/drm/nouveau/nouveau_drv.h b/drivers/gpu/drm/nouveau/nouveau_drv.h
index c5993aa..92c414a 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_drv.h
+++ b/drivers/gpu/drm/nouveau/nouveau_drv.h
@@ -680,6 +680,7 @@ struct drm_nouveau_private {
        /* exact chipset, derived from NV_PMC_BOOT_0 */
        int chipset;
        int flags;
+       u32 crystal;
 
        void __iomem *mmio;
 

diff --git a/drivers/gpu/drm/nouveau/nouveau_state.c b/drivers/gpu/drm/nouveau/nouveau_state.c
index f104725..baaecf1 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_state.c
+++ b/drivers/gpu/drm/nouveau/nouveau_state.c
@@ -984,7 +984,7 @@ static int nouveau_remove_conflicting_drivers(struct drm_device *dev)
 int nouveau_load(struct drm_device *dev, unsigned long flags)
 {
        struct drm_nouveau_private *dev_priv;
-       uint32_t reg0;
+       uint32_t reg0, strap;
        resource_size_t mmio_start_offs;
        int ret;
 
@@ -1074,6 +1074,23 @@ int nouveau_load(struct drm_device *dev, unsigned long flags)
        NV_INFO(dev, "Detected an NV%2x generation card (0x%08x)\n",
                dev_priv->card_type, reg0);
 
+       /* determine frequency of timing crystal */
+       strap = nv_rd32(dev, 0x101000);
+       if ( dev_priv->chipset < 0x17 ||
+           (dev_priv->chipset >= 0x20 && dev_priv->chipset <= 0x25))
+               strap &= 0x00000040;
+       else
+               strap &= 0x00400040;
+
+       switch (strap) {
+       case 0x00000000: dev_priv->crystal = 13500; break;
+       case 0x00000040: dev_priv->crystal = 14318; break;
+       case 0x00400000: dev_priv->crystal = 27000; break;
+       case 0x00400040: dev_priv->crystal = 25000; break;
+       }
+
+       NV_DEBUG(dev, "crystal freq: %dKHz\n", dev_priv->crystal);
+
        /* Determine whether we'll attempt acceleration or not, some
         * cards are disabled by default here due to them being known
         * non-functional, or never been tested due to lack of hw.