1 /* 2 * Copyright 2012 Red Hat Inc. 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice shall be included in 12 * all copies or substantial portions of the Software. 13 * 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR 18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 20 * OTHER DEALINGS IN THE SOFTWARE. 21 * 22 * Authors: Ben Skeggs 23 */ 24 #include "priv.h" 25 #include "regsnv04.h" 26 27 static void 28 nv41_timer_init(struct nvkm_timer *tmr) 29 { 30 struct nvkm_subdev *subdev = &tmr->subdev; 31 struct nvkm_device *device = subdev->device; 32 u32 f = device->crystal; 33 u32 m = 1, n, d; 34 35 /* aim for 31.25MHz, which gives us nanosecond timestamps */ 36 d = 1000000 / 32; 37 n = f; 38 39 while (n < (d * 2)) { 40 n += (n / m); 41 m++; 42 } 43 44 /* reduce ratio to acceptable values */ 45 while (((n % 5) == 0) && ((d % 5) == 0)) { 46 n /= 5; 47 d /= 5; 48 } 49 50 while (((n % 2) == 0) && ((d % 2) == 0)) { 51 n /= 2; 52 d /= 2; 53 } 54 55 while (n > 0xffff || d > 0xffff) { 56 n >>= 1; 57 d >>= 1; 58 } 59 60 nvkm_debug(subdev, "input frequency : %dHz\n", f); 61 nvkm_debug(subdev, "input multiplier: %d\n", m); 62 nvkm_debug(subdev, "numerator : %08x\n", n); 63 nvkm_debug(subdev, "denominator : %08x\n", d); 64 nvkm_debug(subdev, "timer frequency : %dHz\n", (f * m) * d / n); 65 66 nvkm_wr32(device, 0x009220, m - 1); 67 nvkm_wr32(device, NV04_PTIMER_NUMERATOR, n); 68 nvkm_wr32(device, NV04_PTIMER_DENOMINATOR, d); 69 } 70 71 static const struct nvkm_timer_func 72 nv41_timer = { 73 .init = nv41_timer_init, 74 .intr = nv04_timer_intr, 75 .read = nv04_timer_read, 76 .time = nv04_timer_time, 77 .alarm_init = nv04_timer_alarm_init, 78 .alarm_fini = nv04_timer_alarm_fini, 79 }; 80 81 int 82 nv41_timer_new(struct nvkm_device *device, enum nvkm_subdev_type type, int inst, 83 struct nvkm_timer **ptmr) 84 { 85 return nvkm_timer_new_(&nv41_timer, device, type, inst, ptmr); 86 } 87