drm/nv40/pm: convert to new pwm hooks, also fixing pwm type detection

A NV49 appeared a while back that was using the "nv41 style" pwm registers,
rather than the "nv40 style" ones my board is using.  This disproves the
previous theory that the pwm controller choice is chipset-specific.

So, after looking at a bunch of vbios images it appears that the next viable
theory is that we should select the pwm controller to use based on the gpio
line the fan is tied to, just like we do on nv50.

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

drivers/gpu/drm/nouveau/nv40_pm.c

@@ -348,54 +348,46 @@ resume:
 }
 
 int
-nv40_pm_fanspeed_get(struct drm_device *dev)
+nv40_pm_pwm_get(struct drm_device *dev, struct dcb_gpio_entry *gpio,
+		u32 *divs, u32 *duty)
 {
-	u32 reg = nv_rd32(dev, 0x0010f0);
-	if (reg & 0x80000000) {
-		u32 duty = (reg & 0x7fff0000) >> 16;
-		u32 divs = (reg & 0x00007fff);
-		if (divs && divs >= duty)
-			return ((divs - duty) * 100) / divs;
+	if (gpio->line == 2) {
+		u32 reg = nv_rd32(dev, 0x0010f0);
+		if (reg & 0x80000000) {
+			*duty = (reg & 0x7fff0000) >> 16;
+			*divs = (reg & 0x00007fff);
+			return 0;
+		}
+	} else
+	if (gpio->line == 9) {
+		u32 reg = nv_rd32(dev, 0x0015f4);
+		if (reg & 0x80000000) {
+			*divs = nv_rd32(dev, 0x0015f8);
+			*duty = (reg & 0x7fffffff);
+			return 0;
+		}
+	} else {
+		NV_ERROR(dev, "unknown pwm ctrl for gpio %d\n", gpio->line);
+		return -ENODEV;
 	}
 
-	return 100;
+	return -EINVAL;
 }
 
 int
-nv40_pm_fanspeed_set(struct drm_device *dev, int percent)
+nv40_pm_pwm_set(struct drm_device *dev, struct dcb_gpio_entry *gpio,
+		u32 divs, u32 duty)
 {
-	struct drm_nouveau_private *dev_priv = dev->dev_private;
-	struct nouveau_pm_engine *pm = &dev_priv->engine.pm;
-	u32 divs = pm->pwm_divisor;
-	u32 duty = ((100 - percent) * divs) / 100;
-
-	nv_wr32(dev, 0x0010f0, 0x80000000 | (duty << 16) | divs);
-	return 0;
-}
-
-int
-nv41_pm_fanspeed_get(struct drm_device *dev)
-{
-	u32 reg = nv_rd32(dev, 0x0015f4);
-	if (reg & 0x80000000) {
-		u32 divs = nv_rd32(dev, 0x0015f8);
-		u32 duty = (reg & 0x7fffffff);
-		if (divs && divs >= duty)
-			return ((divs - duty) * 100) / divs;
+	if (gpio->line == 2) {
+		nv_wr32(dev, 0x0010f0, 0x80000000 | (duty << 16) | divs);
+	} else
+	if (gpio->line == 9) {
+		nv_wr32(dev, 0x0015f8, divs);
+		nv_wr32(dev, 0x0015f4, duty | 0x80000000);
+	} else {
+		NV_ERROR(dev, "unknown pwm ctrl for gpio %d\n", gpio->line);
+		return -ENODEV;
 	}
 
-	return 100;
-}
-
-int
-nv41_pm_fanspeed_set(struct drm_device *dev, int percent)
-{
-	struct drm_nouveau_private *dev_priv = dev->dev_private;
-	struct nouveau_pm_engine *pm = &dev_priv->engine.pm;
-	u32 divs = pm->pwm_divisor;
-	u32 duty = ((100 - percent) * divs) / 100;
-
-	nv_wr32(dev, 0x0015f8, divs);
-	nv_wr32(dev, 0x0015f4, duty | 0x80000000);
 	return 0;
 }