Legacy backlight changes:

  - add support for 965GM
  - make sure legacy enabled systems don't reduce the range of backlight values we can present to the user

3 files changed, 61 insertions, 26 deletions

diff --git a/src/i810_reg.h b/src/i810_reg.h
index 248df049..d1fed22c 100644
--- a/src/i810_reg.h
+++ b/src/i810_reg.h
@@ -822,6 +822,7 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 # define PP_SEQUENCE_MASK			0x30000000
 
 #define PP_CONTROL	0x61204
+# define POWER_DOWN_ON_RESET			(1 << 1)
 # define POWER_TARGET_ON			(1 << 0)
 
 #define LVDSPP_ON       0x61208
@@ -1066,6 +1067,7 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 #define BLC_PWM_CTL		0x61254
 #define BACKLIGHT_MODULATION_FREQ_SHIFT		(17)
+#define BACKLIGHT_MODULATION_FREQ_SHIFT2	(16)
 /**
  * This is the most significant 15 bits of the number of backlight cycles in a
  * complete cycle of the modulated backlight control.
@@ -1073,7 +1075,9 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  * The actual value is this field multiplied by two.
  */
 #define BACKLIGHT_MODULATION_FREQ_MASK		(0x7fff << 17)
+#define BACKLIGHT_MODULATION_FREQ_MASK2		(0xffff << 16)
 #define BLM_LEGACY_MODE				(1 << 16)
+
 /**
  * This is the number of cycles out of the backlight modulation cycle for which
  * the backlight is on.
@@ -1084,6 +1088,10 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define BACKLIGHT_DUTY_CYCLE_SHIFT		(0)
 #define BACKLIGHT_DUTY_CYCLE_MASK		(0xffff)
 
+/* On 965+ backlight control is in another register */
+#define BLC_PWM_CTL2			0x61250
+#define 	BLM_LEGACY_MODE2	(1 << 30)
+
 #define BLM_CTL			0x61260
 #define BLM_THRESHOLD_0		0x61270
 #define BLM_THRESHOLD_1		0x61274
diff --git a/src/i830.h b/src/i830.h
index bf072a16..a8de0e6c 100644
--- a/src/i830.h
+++ b/src/i830.h
@@ -532,6 +532,7 @@ typedef struct _I830Rec {
    CARD32 savePaletteB[256];
    CARD32 saveSWF[17];
    CARD32 saveBLC_PWM_CTL;
+   CARD32 saveBLC_PWM_CTL2;
    CARD32 saveFBC_CFB_BASE;
    CARD32 saveFBC_LL_BASE;
    CARD32 saveFBC_CONTROL2;
diff --git a/src/i830_lvds.c b/src/i830_lvds.c
index 246008ba..18e5c2b3 100644
--- a/src/i830_lvds.c
+++ b/src/i830_lvds.c
@@ -46,6 +46,30 @@ struct i830_lvds_priv {
     int		    backlight_duty_cycle;
 };
 
+/**
+ * Use legacy backlight controls?
+ *
+ * \param pI830 device in question
+ *
+ * Returns TRUE if legacy backlight should be used, false otherwise.
+ */
+static int
+i830_lvds_backlight_legacy(I830Ptr pI830)
+{
+    CARD32 blc_pwm_ctl, blc_pwm_ctl2;
+
+    /* 965GM+ change the location of the legacy control bit */
+    if (IS_I965GM(pI830)) {
+	blc_pwm_ctl2 = INREG(BLC_PWM_CTL2);
+	if (blc_pwm_ctl2 & BLM_LEGACY_MODE2)
+	    return TRUE;
+    } else {
+	blc_pwm_ctl = INREG(BLC_PWM_CTL);
+	if (blc_pwm_ctl & BLM_LEGACY_MODE)
+	    return TRUE;
+    }
+    return FALSE;
+}
 
 /**
  * Sets the backlight level.
@@ -59,18 +83,12 @@ i830_lvds_set_backlight(xf86OutputPtr output, int level)
     I830Ptr pI830 = I830PTR(pScrn);
     CARD32 blc_pwm_ctl;
 
+    if (i830_lvds_backlight_legacy(pI830))
+	pciWriteByte(pI830->PciTag, LEGACY_BACKLIGHT_BRIGHTNESS, 0xfe);
+
     blc_pwm_ctl = INREG(BLC_PWM_CTL);
-    if (blc_pwm_ctl & BLM_LEGACY_MODE)
-    {
-	pciWriteByte (pI830->PciTag, 
-		      LEGACY_BACKLIGHT_BRIGHTNESS,
-		      level & 0xff);
-    }
-    else
-    {
-	blc_pwm_ctl &= ~BACKLIGHT_DUTY_CYCLE_MASK;
-	OUTREG(BLC_PWM_CTL, blc_pwm_ctl | (level << BACKLIGHT_DUTY_CYCLE_SHIFT));
-    }
+    blc_pwm_ctl &= ~BACKLIGHT_DUTY_CYCLE_MASK;
+    OUTREG(BLC_PWM_CTL, blc_pwm_ctl | (level << BACKLIGHT_DUTY_CYCLE_SHIFT));
 }
 
 /**
@@ -82,12 +100,24 @@ i830_lvds_get_max_backlight(xf86OutputPtr output)
     ScrnInfoPtr pScrn = output->scrn;
     I830Ptr	pI830 = I830PTR(pScrn);
     CARD32	pwm_ctl = INREG(BLC_PWM_CTL);
+    CARD32	val;
+
+    if (IS_I965GM(pI830)) {
+	val = ((pwm_ctl & BACKLIGHT_MODULATION_FREQ_MASK2) >>
+	       BACKLIGHT_MODULATION_FREQ_SHIFT2);
+    } else {
+	val = ((pwm_ctl & BACKLIGHT_MODULATION_FREQ_MASK) >>
+	       BACKLIGHT_MODULATION_FREQ_SHIFT) * 2;
+    }
     
-    if (pwm_ctl & BLM_LEGACY_MODE)
-	return 0xff;
-    else
-	return ((pwm_ctl & BACKLIGHT_MODULATION_FREQ_MASK) >>
-		BACKLIGHT_MODULATION_FREQ_SHIFT) * 2;
+    /*
+     * In legacy control mode, backlight value is calculated:
+     * if (LBB[7:0] != 0xff)
+     *     backlight = BLC_PWM_CTL[15:0] *  BPC[7:0]
+     * else
+     *     backlight = BLC_PWM_CTL[15:0]
+     */
+    return val;
 }
 
 /**
@@ -138,21 +168,15 @@ i830_lvds_save (xf86OutputPtr output)
     ScrnInfoPtr		    pScrn = output->scrn;
     I830Ptr		    pI830 = I830PTR(pScrn);
 
+    if (IS_I965GM(pI830))
+	pI830->saveBLC_PWM_CTL2 = INREG(BLC_PWM_CTL2);
     pI830->savePP_ON = INREG(LVDSPP_ON);
     pI830->savePP_OFF = INREG(LVDSPP_OFF);
     pI830->savePP_CONTROL = INREG(PP_CONTROL);
     pI830->savePP_CYCLE = INREG(PP_CYCLE);
     pI830->saveBLC_PWM_CTL = INREG(BLC_PWM_CTL);
-    if (pI830->saveBLC_PWM_CTL & BLM_LEGACY_MODE)
-    {
-	dev_priv->backlight_duty_cycle = pciReadByte (pI830->PciTag,
-						      LEGACY_BACKLIGHT_BRIGHTNESS);
-    }
-    else
-    {
-	dev_priv->backlight_duty_cycle = (pI830->saveBLC_PWM_CTL &
-					  BACKLIGHT_DUTY_CYCLE_MASK);
-    }
+    dev_priv->backlight_duty_cycle = (pI830->saveBLC_PWM_CTL &
+				      BACKLIGHT_DUTY_CYCLE_MASK);
 
     /*
      * If the light is off at server startup, just make it full brightness
@@ -167,6 +191,8 @@ i830_lvds_restore(xf86OutputPtr output)
     ScrnInfoPtr	pScrn = output->scrn;
     I830Ptr	pI830 = I830PTR(pScrn);
 
+    if (IS_I965GM(pI830))
+	OUTREG(BLC_PWM_CTL2, pI830->saveBLC_PWM_CTL2);
     OUTREG(BLC_PWM_CTL, pI830->saveBLC_PWM_CTL);
     OUTREG(LVDSPP_ON, pI830->savePP_ON);
     OUTREG(LVDSPP_OFF, pI830->savePP_OFF);