drm/nouveau/volt: add GM20B driver

Add basic GM20B volt driver that reuses the GK20A logic.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/include/nvkm/subdev/volt.h

@@ -20,4 +20,5 @@ int nvkm_volt_set_id(struct nvkm_volt *, u8 id, int condition);
 int nv40_volt_new(struct nvkm_device *, int, struct nvkm_volt **);
 int gk104_volt_new(struct nvkm_device *, int, struct nvkm_volt **);
 int gk20a_volt_new(struct nvkm_device *, int, struct nvkm_volt **);
+int gm20b_volt_new(struct nvkm_device *, int, struct nvkm_volt **);
 #endif

drivers/gpu/drm/nouveau/nvkm/engine/device/base.c

@@ -2093,6 +2093,7 @@ nv12b_chipset = {
 	.secboot = gm20b_secboot_new,
 	.timer = gk20a_timer_new,
 	.ce[2] = gm200_ce_new,
+	.volt = gm20b_volt_new,
 	.dma = gf119_dma_new,
 	.fifo = gm20b_fifo_new,
 	.gr = gm20b_gr_new,

drivers/gpu/drm/nouveau/nvkm/subdev/volt/Kbuild

@@ -3,3 +3,4 @@ nvkm-y += nvkm/subdev/volt/gpio.o
 nvkm-y += nvkm/subdev/volt/nv40.o
 nvkm-y += nvkm/subdev/volt/gk104.o
 nvkm-y += nvkm/subdev/volt/gk20a.o
+nvkm-y += nvkm/subdev/volt/gm20b.o

drivers/gpu/drm/nouveau/nvkm/subdev/volt/gm20b.c

+/*
+ * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include "priv.h"
+#include "gk20a.h"
+
+#include <core/tegra.h>
+
+const struct cvb_coef gm20b_cvb_coef[] = {
+	/* KHz,             c0,      c1,   c2 */
+	/*  76800 */ { 1786666,  -85625, 1632 },
+	/* 153600 */ { 1846729,  -87525, 1632 },
+	/* 230400 */ { 1910480,  -89425, 1632 },
+	/* 307200 */ { 1977920,  -91325, 1632 },
+	/* 384000 */ { 2049049,  -93215, 1632 },
+	/* 460800 */ { 2122872,  -95095, 1632 },
+	/* 537600 */ { 2201331,  -96985, 1632 },
+	/* 614400 */ { 2283479,  -98885, 1632 },
+	/* 691200 */ { 2369315, -100785, 1632 },
+	/* 768000 */ { 2458841, -102685, 1632 },
+	/* 844800 */ { 2550821, -104555, 1632 },
+	/* 921600 */ { 2647676, -106455, 1632 },
+};
+
+int
+gm20b_volt_new(struct nvkm_device *device, int index, struct nvkm_volt **pvolt)
+{
+	struct gk20a_volt *volt;
+
+	volt = kzalloc(sizeof(*volt), GFP_KERNEL);
+	if (!volt)
+		return -ENOMEM;
+	*pvolt = &volt->base;
+
+	return _gk20a_volt_ctor(device, index, gm20b_cvb_coef,
+				ARRAY_SIZE(gm20b_cvb_coef), volt);
+}