drm/nouveau/therm: calculate the pwm divisor on nv50+

v2: Martin Peres <martin.peres@labri.fr>
- fixed unintentional use of floating point

Signed-off-by: Martin Peres <martin.peres@labri.fr>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

3 files changed, 37 insertions, 4 deletions

diff --git a/drivers/gpu/drm/nouveau/core/subdev/therm/fan.c b/drivers/gpu/drm/nouveau/core/subdev/therm/fan.c
index b7339b52559e..409b95d5b679 100644
--- a/drivers/gpu/drm/nouveau/core/subdev/therm/fan.c
+++ b/drivers/gpu/drm/nouveau/core/subdev/therm/fan.c
@@ -81,10 +81,10 @@ nouveau_therm_fan_set(struct nouveau_therm *therm, int percent)
         if (ret == 0) {
                 divs = priv->bios_perf_fan.pwm_divisor;
                 if (priv->bios_fan.pwm_freq) {
-                        /*XXX: PNVIO clock more than likely... */
-                        divs = 135000 /priv->bios_fan.pwm_freq;
-                        if (nv_device(therm)->chipset < 0xa3)
-                                divs /= 4;
+                        divs = 1;
+                        if (priv->fan.pwm_clock)
+                                divs = priv->fan.pwm_clock(therm);
+                        divs /= priv->bios_fan.pwm_freq;
                 }
 
                 duty = ((divs * percent) + 99) / 100;
@@ -163,6 +163,11 @@ nouveau_therm_fan_safety_checks(struct nouveau_therm *therm)
                 priv->bios_fan.min_duty = priv->bios_fan.max_duty;
 }
 
+int nouveau_fan_pwm_clock_dummy(struct nouveau_therm *therm)
+{
+        return 1;
+}
+
 int
 nouveau_therm_fan_ctor(struct nouveau_therm *therm)
 {
diff --git a/drivers/gpu/drm/nouveau/core/subdev/therm/nv50.c b/drivers/gpu/drm/nouveau/core/subdev/therm/nv50.c
index f7f51f35d18b..de7dc20ed436 100644
--- a/drivers/gpu/drm/nouveau/core/subdev/therm/nv50.c
+++ b/drivers/gpu/drm/nouveau/core/subdev/therm/nv50.c
@@ -80,6 +80,32 @@ nv50_fan_pwm_set(struct nouveau_therm *therm, int line, u32 divs, u32 duty)
 }
 
 int
+nv50_fan_pwm_clock(struct nouveau_therm *therm)
+{
+        int chipset = nv_device(therm)->chipset;
+        int crystal = nv_device(therm)->crystal;
+        int pwm_clock;
+
+        /* determine the PWM source clock */
+        if (chipset > 0x50 && chipset < 0x94) {
+                u8 pwm_div = nv_rd32(therm, 0x410c);
+                if (nv_rd32(therm, 0xc040) & 0x800000) {
+                        /* Use the HOST clock (100 MHz)
+                        * Where does this constant(2.4) comes from? */
+                        pwm_clock = (100000000 >> pwm_div) / 10 / 24;
+                } else {
+                        /* Where does this constant(20) comes from? */
+                        pwm_clock = (crystal * 1000) >> pwm_div;
+                        pwm_clock /= 20;
+                }
+        } else {
+                pwm_clock = (crystal * 1000) / 20;
+        }
+
+        return pwm_clock;
+}
+
+int
 nv50_temp_get(struct nouveau_therm *therm)
 {
         return nv_rd32(therm, 0x20400);
@@ -107,6 +133,7 @@ nv50_therm_ctor(struct nouveau_object *parent,
 
         priv->fan.pwm_get = nv50_fan_pwm_get;
         priv->fan.pwm_set = nv50_fan_pwm_set;
+        priv->fan.pwm_clock = nv50_fan_pwm_clock;
 
         therm->temp_get = nv50_temp_get;
         therm->fan_get = nouveau_therm_fan_get;
diff --git a/drivers/gpu/drm/nouveau/core/subdev/therm/priv.h b/drivers/gpu/drm/nouveau/core/subdev/therm/priv.h
index b7207b4524f6..c53eb5396972 100644
--- a/drivers/gpu/drm/nouveau/core/subdev/therm/priv.h
+++ b/drivers/gpu/drm/nouveau/core/subdev/therm/priv.h
@@ -42,6 +42,7 @@ struct nouveau_therm_priv {
 
                 int (*pwm_get)(struct nouveau_therm *, int line, u32*, u32*);
                 int (*pwm_set)(struct nouveau_therm *, int line, u32, u32);
+                int (*pwm_clock)(struct nouveau_therm *);
         } fan;
 
         /* ic */