1 files changed, 51 insertions, 0 deletions

diff --git a/drivers/gpu/drm/nouveau/nv04_timer.c b/drivers/gpu/drm/nouveau/nv04_timer.c
new file mode 100644
index 00000000000..1d09ddd5739
--- /dev/null
+++ b/drivers/gpu/drm/nouveau/nv04_timer.c
@@ -0,0 +1,51 @@
+#include "drmP.h"
+#include "drm.h"
+#include "nouveau_drv.h"
+#include "nouveau_drm.h"
+
+int
+nv04_timer_init(struct drm_device *dev)
+{
+        nv_wr32(dev, NV04_PTIMER_INTR_EN_0, 0x00000000);
+        nv_wr32(dev, NV04_PTIMER_INTR_0, 0xFFFFFFFF);
+
+        /* Just use the pre-existing values when possible for now; these regs
+         * are not written in nv (driver writer missed a /4 on the address), and
+         * writing 8 and 3 to the correct regs breaks the timings on the LVDS
+         * hardware sequencing microcode.
+         * A correct solution (involving calculations with the GPU PLL) can
+         * be done when kernel modesetting lands
+         */
+        if (!nv_rd32(dev, NV04_PTIMER_NUMERATOR) ||
+                                !nv_rd32(dev, NV04_PTIMER_DENOMINATOR)) {
+                nv_wr32(dev, NV04_PTIMER_NUMERATOR, 0x00000008);
+                nv_wr32(dev, NV04_PTIMER_DENOMINATOR, 0x00000003);
+        }
+
+        return 0;
+}
+
+uint64_t
+nv04_timer_read(struct drm_device *dev)
+{
+        uint32_t low;
+        /* From kmmio dumps on nv28 this looks like how the blob does this.
+         * It reads the high dword twice, before and after.
+         * The only explanation seems to be that the 64-bit timer counter
+         * advances between high and low dword reads and may corrupt the
+         * result. Not confirmed.
+         */
+        uint32_t high2 = nv_rd32(dev, NV04_PTIMER_TIME_1);
+        uint32_t high1;
+        do {
+                high1 = high2;
+                low = nv_rd32(dev, NV04_PTIMER_TIME_0);
+                high2 = nv_rd32(dev, NV04_PTIMER_TIME_1);
+        } while (high1 != high2);
+        return (((uint64_t)high2) << 32) | (uint64_t)low;
+}
+
+void
+nv04_timer_takedown(struct drm_device *dev)
+{
+}