drm/i915/dvo/ch7xxx: Fix suspend/resume

Poke a few more bits into the ch7xxx to make
it output a picture after being reset during S3.

In particular we need to set the input buffer select (IBS),
and enable VGA vsync output on the BCO pin. Selecting
VGA hsync on the c/h sync pin doesn't actually seem necessary
on my ADD card at least, but the BIOS selects it so why not.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221122120825.26338-2-ville.syrjala@linux.intel.com
Acked-by: Jani Nikula <jani.nikula@intel.com>

diff --git a/drivers/gpu/drm/i915/display/dvo_ch7xxx.c b/drivers/gpu/drm/i915/display/dvo_ch7xxx.c
index 54f58ba44b9f0d21e40acf9b8f131e6d9bf1f429..6d948520e9a6c22f7f611e1cb6dd27eb7ede5c2f 100644 (file)
--- a/drivers/gpu/drm/i915/display/dvo_ch7xxx.c
+++ b/drivers/gpu/drm/i915/display/dvo_ch7xxx.c
@@ -50,15 +50,26 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define CH7xxx_INPUT_CLOCK     0x1d
 #define CH7xxx_GPIO            0x1e
 #define CH7xxx_GPIO_HPIR       (1<<3)
-#define CH7xxx_IDF             0x1f
 
+#define CH7xxx_IDF             0x1f
+#define CH7xxx_IDF_IBS         (1<<7)
+#define CH7xxx_IDF_DES         (1<<6)
 #define CH7xxx_IDF_HSP         (1<<3)
 #define CH7xxx_IDF_VSP         (1<<4)
 
 #define CH7xxx_CONNECTION_DETECT 0x20
 #define CH7xxx_CDET_DVI                (1<<5)
 
-#define CH7301_DAC_CNTL                0x21
+#define CH7xxx_DAC_CNTL                0x21
+#define CH7xxx_SYNCO_MASK      (3 << 3)
+#define CH7xxx_SYNCO_VGA_HSYNC (1 << 3)
+
+#define CH7xxx_CLOCK_OUTPUT    0x22
+#define CH7xxx_BCOEN           (1 << 4)
+#define CH7xxx_BCOP            (1 << 3)
+#define CH7xxx_BCO_MASK                (7 << 0)
+#define CH7xxx_BCO_VGA_VSYNC   (6 << 0)
+
 #define CH7301_HOTPLUG         0x23
 #define CH7xxx_TCTL            0x31
 #define CH7xxx_TVCO            0x32
@@ -301,6 +312,8 @@ static void ch7xxx_mode_set(struct intel_dvo_device *dvo,
 
        ch7xxx_readb(dvo, CH7xxx_IDF, &idf);
 
+       idf |= CH7xxx_IDF_IBS;
+
        idf &= ~(CH7xxx_IDF_HSP | CH7xxx_IDF_VSP);
        if (mode->flags & DRM_MODE_FLAG_PHSYNC)
                idf |= CH7xxx_IDF_HSP;
@@ -309,6 +322,11 @@ static void ch7xxx_mode_set(struct intel_dvo_device *dvo,
                idf |= CH7xxx_IDF_VSP;
 
        ch7xxx_writeb(dvo, CH7xxx_IDF, idf);
+
+       ch7xxx_writeb(dvo, CH7xxx_DAC_CNTL,
+                     CH7xxx_SYNCO_VGA_HSYNC);
+       ch7xxx_writeb(dvo, CH7xxx_CLOCK_OUTPUT,
+                     CH7xxx_BCOEN | CH7xxx_BCO_VGA_VSYNC);
 }
 
 /* set the CH7xxx power state */