[Nouveau] [RFC 10/16] drm/nouveau/timer: skip calibration on GK20A

[Alexandre Courbot]

GK20A's timer is directly attached to the system timer and cannot be
calibrated. Skip the calibration phase on that chip since the
corresponding registers do not exist.

Signed-off-by: Alexandre Courbot <acourbot at nvidia.com>
---
 drivers/gpu/drm/nouveau/core/subdev/timer/nv04.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/core/subdev/timer/nv04.c b/drivers/gpu/drm/nouveau/core/subdev/timer/nv04.c
index c0bdd10..822fe0d 100644
--- a/drivers/gpu/drm/nouveau/core/subdev/timer/nv04.c
+++ b/drivers/gpu/drm/nouveau/core/subdev/timer/nv04.c
@@ -185,6 +185,10 @@ nv04_timer_init(struct nouveau_object *object)
 	if (ret)
 		return ret;
 
+	/* gk20a does not have the calibration registers */
+	if (device->chipset == 0xea)
+		goto skip_clk_init;
+
 	/* aim for 31.25MHz, which gives us nanosecond timestamps */
 	d = 1000000 / 32;
 
@@ -235,20 +239,23 @@ nv04_timer_init(struct nouveau_object *object)
 		d >>= 1;
 	}
 
-	/* restore the time before suspend */
-	lo = priv->suspend_time;
-	hi = (priv->suspend_time >> 32);
-
 	nv_debug(priv, "input frequency : %dHz\n", f);
 	nv_debug(priv, "input multiplier: %d\n", m);
 	nv_debug(priv, "numerator       : 0x%08x\n", n);
 	nv_debug(priv, "denominator     : 0x%08x\n", d);
 	nv_debug(priv, "timer frequency : %dHz\n", (f * m) * d / n);
-	nv_debug(priv, "time low        : 0x%08x\n", lo);
-	nv_debug(priv, "time high       : 0x%08x\n", hi);
 
 	nv_wr32(priv, NV04_PTIMER_NUMERATOR, n);
 	nv_wr32(priv, NV04_PTIMER_DENOMINATOR, d);
+
+skip_clk_init:
+	/* restore the time before suspend */
+	lo = priv->suspend_time;
+	hi = (priv->suspend_time >> 32);
+
+	nv_debug(priv, "time low        : 0x%08x\n", lo);
+	nv_debug(priv, "time high       : 0x%08x\n", hi);
+
 	nv_wr32(priv, NV04_PTIMER_INTR_0, 0xffffffff);
 	nv_wr32(priv, NV04_PTIMER_INTR_EN_0, 0x00000000);
 	nv_wr32(priv, NV04_PTIMER_TIME_1, hi);
-- 
1.8.5.3