drm/nouveau/mxm: implement ROM shadow method

Untested, -ENOHW.

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

diff --git a/drivers/gpu/drm/nouveau/nouveau_mxm.c b/drivers/gpu/drm/nouveau/nouveau_mxm.c
index 840c88f..8bccddf 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_mxm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_mxm.c
@@ -471,8 +471,47 @@ mxm_dcb_sanitise(struct drm_device *dev)
 }
 
 static bool
+mxm_shadow_rom_fetch(struct nouveau_i2c_chan *i2c, u8 addr,
+                    u8 offset, u8 size, u8 *data)
+{
+       struct i2c_msg msgs[] = {
+               { .addr = addr, .flags = 0, .len = 1, .buf = &offset },
+               { .addr = addr, .flags = I2C_M_RD, .len = size, .buf = data, },
+       };
+
+       return i2c_transfer(&i2c->adapter, msgs, 2) == 2;
+}
+
+static bool
 mxm_shadow_rom(struct drm_device *dev, u8 version)
 {
+       struct drm_nouveau_private *dev_priv = dev->dev_private;
+       struct nouveau_i2c_chan *i2c = NULL;
+       u8 i2cidx, mxms[6], addr, size;
+
+       i2cidx = mxm_ddc_map(dev, 1 /* LVDS_DDC */) & 0x0f;
+       if (i2cidx < 0x0f)
+               i2c = nouveau_i2c_find(dev, i2cidx);
+       if (!i2c)
+               return false;
+
+       addr = 0x54;
+       if (!mxm_shadow_rom_fetch(i2c, addr, 0, 6, mxms)) {
+               addr = 0x56;
+               if (!mxm_shadow_rom_fetch(i2c, addr, 0, 6, mxms))
+                       return false;
+       }
+
+       dev_priv->mxms = mxms;
+       size = mxms_headerlen(dev) + mxms_structlen(dev);
+       dev_priv->mxms = kmalloc(size, GFP_KERNEL);
+
+       if (dev_priv->mxms &&
+           mxm_shadow_rom_fetch(i2c, addr, 0, size, dev_priv->mxms))
+               return true;
+
+       kfree(dev_priv->mxms);
+       dev_priv->mxms = NULL;
        return false;
 }