drm/i915: Support for ns2501-DVO

This patch adds support for the ns2501 DVO, found in some older Fujitsu/Siemens Labtops.
It is in the state of "works for me".
Includes now proper DPMS support. Includes switching between resolutions -
from 640x480 to 1024x768.
Currently assumes that the native display resolution is 1024x768.

The ns2501 seems to be rather critical - if the output PLL is not
running, the chip doesn't seem to be clocked and then doesn't react
on i2c messages. Thus, a quick'n-dirty trick ensures that the DVO
is active before submitting any i2c messages to it. This is
probably to be reviewed.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=17902
Signed-off-by: Thomas Richter <thor@math.tu-berlin.de>
[danvet: fixup whitespace fail.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 9 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/intel_dvo.c b/drivers/gpu/drm/i915/intel_dvo.c
index 556cf6bf2a55..03dfdff8e003 100644
--- a/drivers/gpu/drm/i915/intel_dvo.c
+++ b/drivers/gpu/drm/i915/intel_dvo.c
@@ -37,6 +37,7 @@
 #define SIL164_ADDR     0x38
 #define CH7xxx_ADDR     0x76
 #define TFP410_ADDR     0x38
+#define NS2501_ADDR     0x38
 
 static const struct intel_dvo_device intel_dvo_devices[] = {
         {
@@ -74,7 +75,14 @@ static const struct intel_dvo_device intel_dvo_devices[] = {
                 .slave_addr = 0x75,
                 .gpio = GMBUS_PORT_DPB,
                 .dev_ops = &ch7017_ops,
-        }
+        },
+        {
+                .type = INTEL_DVO_CHIP_TMDS,
+                .name = "ns2501",
+                .dvo_reg = DVOC,
+                .slave_addr = NS2501_ADDR,
+                .dev_ops = &ns2501_ops,
+       }
 };
 
 struct intel_dvo {