drm/nv50/pm: add support for pwm fan control

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

1 files changed, 74 insertions, 0 deletions

diff --git a/drivers/gpu/drm/nouveau/nv50_pm.c b/drivers/gpu/drm/nouveau/nv50_pm.c
index 3d5a86b98282..713c718206e3 100644
--- a/drivers/gpu/drm/nouveau/nv50_pm.c
+++ b/drivers/gpu/drm/nouveau/nv50_pm.c
@@ -144,3 +144,77 @@ nv50_pm_clock_set(struct drm_device *dev, void *pre_state)
         kfree(state);
 }
 
+struct pwm_info {
+        int id;
+        int invert;
+        u8  tag;
+        u32 ctrl;
+        int line;
+};
+
+static int
+nv50_pm_fanspeed_pwm(struct drm_device *dev, struct pwm_info *pwm)
+{
+        struct dcb_gpio_entry *gpio;
+
+        gpio = nouveau_bios_gpio_entry(dev, 0x09);
+        if (gpio) {
+                pwm->tag = gpio->tag;
+                pwm->id = (gpio->line == 9) ? 1 : 0;
+                pwm->invert = gpio->state[0] & 1;
+                pwm->ctrl = (gpio->line < 16) ? 0xe100 : 0xe28c;
+                pwm->line = (gpio->line & 0xf);
+                return 0;
+        }
+
+        return -ENOENT;
+}
+
+int
+nv50_pm_fanspeed_get(struct drm_device *dev)
+{
+        struct drm_nouveau_private *dev_priv = dev->dev_private;
+        struct nouveau_gpio_engine *pgpio = &dev_priv->engine.gpio;
+        struct pwm_info pwm;
+        int ret;
+
+        ret = nv50_pm_fanspeed_pwm(dev, &pwm);
+        if (ret)
+                return ret;
+
+        if (nv_rd32(dev, pwm.ctrl) & (0x00000001 << pwm.line)) {
+                u32 divs = nv_rd32(dev, 0x00e114 + (pwm.id * 8));
+                u32 duty = nv_rd32(dev, 0x00e118 + (pwm.id * 8));
+                if (divs) {
+                        divs = max(divs, duty);
+                        if (pwm.invert)
+                                duty = divs - duty;
+                        return (duty * 100) / divs;
+                }
+
+                return 0;
+        }
+
+        return pgpio->get(dev, pwm.tag) * 100;
+}
+
+int
+nv50_pm_fanspeed_set(struct drm_device *dev, int percent)
+{
+        struct pwm_info pwm;
+        u32 divs, duty;
+        int ret;
+
+        ret = nv50_pm_fanspeed_pwm(dev, &pwm);
+        if (ret)
+                return ret;
+
+        divs = nv_rd32(dev, 0x00e114 + (pwm.id * 8));
+        duty = ((divs * percent) + 99) / 100;
+        if (pwm.invert)
+                duty = divs - duty;
+
+        nv_mask(dev, pwm.ctrl, 0x00010001 << pwm.line, 0x00000001 << pwm.line);
+        nv_wr32(dev, 0x00e118 + (pwm.id * 8), 0x80000000 | duty);
+        return 0;
+}