1 /*
2  * Copyright (c) 2014, NVIDIA CORPORATION. All rights reserved.
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 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
19  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
20  * DEALINGS IN THE SOFTWARE.
21  */
22 #include "priv.h"
23 
24 #include <subdev/clk.h>
25 #include <subdev/timer.h>
26 #include <subdev/volt.h>
27 
28 #define BUSY_SLOT	0
29 #define CLK_SLOT	7
30 
31 struct gk20a_pmu_dvfs_data {
32 	int p_load_target;
33 	int p_load_max;
34 	int p_smooth;
35 	unsigned int avg_load;
36 };
37 
38 struct gk20a_pmu {
39 	struct nvkm_pmu base;
40 	struct nvkm_alarm alarm;
41 	struct gk20a_pmu_dvfs_data *data;
42 };
43 
44 struct gk20a_pmu_dvfs_dev_status {
45 	unsigned long total;
46 	unsigned long busy;
47 	int cur_state;
48 };
49 
50 static int
51 gk20a_pmu_dvfs_target(struct gk20a_pmu *pmu, int *state)
52 {
53 	struct nvkm_clk *clk = nvkm_clk(pmu);
54 
55 	return nvkm_clk_astate(clk, *state, 0, false);
56 }
57 
58 static int
59 gk20a_pmu_dvfs_get_cur_state(struct gk20a_pmu *pmu, int *state)
60 {
61 	struct nvkm_clk *clk = nvkm_clk(pmu);
62 
63 	*state = clk->pstate;
64 	return 0;
65 }
66 
67 static int
68 gk20a_pmu_dvfs_get_target_state(struct gk20a_pmu *pmu,
69 				int *state, int load)
70 {
71 	struct gk20a_pmu_dvfs_data *data = pmu->data;
72 	struct nvkm_clk *clk = nvkm_clk(pmu);
73 	int cur_level, level;
74 
75 	/* For GK20A, the performance level is directly mapped to pstate */
76 	level = cur_level = clk->pstate;
77 
78 	if (load > data->p_load_max) {
79 		level = min(clk->state_nr - 1, level + (clk->state_nr / 3));
80 	} else {
81 		level += ((load - data->p_load_target) * 10 /
82 				data->p_load_target) / 2;
83 		level = max(0, level);
84 		level = min(clk->state_nr - 1, level);
85 	}
86 
87 	nv_trace(pmu, "cur level = %d, new level = %d\n", cur_level, level);
88 
89 	*state = level;
90 
91 	if (level == cur_level)
92 		return 0;
93 	else
94 		return 1;
95 }
96 
97 static int
98 gk20a_pmu_dvfs_get_dev_status(struct gk20a_pmu *pmu,
99 			      struct gk20a_pmu_dvfs_dev_status *status)
100 {
101 	status->busy = nv_rd32(pmu, 0x10a508 + (BUSY_SLOT * 0x10));
102 	status->total= nv_rd32(pmu, 0x10a508 + (CLK_SLOT * 0x10));
103 	return 0;
104 }
105 
106 static void
107 gk20a_pmu_dvfs_reset_dev_status(struct gk20a_pmu *pmu)
108 {
109 	nv_wr32(pmu, 0x10a508 + (BUSY_SLOT * 0x10), 0x80000000);
110 	nv_wr32(pmu, 0x10a508 + (CLK_SLOT * 0x10), 0x80000000);
111 }
112 
113 static void
114 gk20a_pmu_dvfs_work(struct nvkm_alarm *alarm)
115 {
116 	struct gk20a_pmu *pmu =
117 		container_of(alarm, struct gk20a_pmu, alarm);
118 	struct gk20a_pmu_dvfs_data *data = pmu->data;
119 	struct gk20a_pmu_dvfs_dev_status status;
120 	struct nvkm_clk *clk = nvkm_clk(pmu);
121 	struct nvkm_volt *volt = nvkm_volt(pmu);
122 	u32 utilization = 0;
123 	int state, ret;
124 
125 	/*
126 	 * The PMU is initialized before CLK and VOLT, so we have to make sure the
127 	 * CLK and VOLT are ready here.
128 	 */
129 	if (!clk || !volt)
130 		goto resched;
131 
132 	ret = gk20a_pmu_dvfs_get_dev_status(pmu, &status);
133 	if (ret) {
134 		nv_warn(pmu, "failed to get device status\n");
135 		goto resched;
136 	}
137 
138 	if (status.total)
139 		utilization = div_u64((u64)status.busy * 100, status.total);
140 
141 	data->avg_load = (data->p_smooth * data->avg_load) + utilization;
142 	data->avg_load /= data->p_smooth + 1;
143 	nv_trace(pmu, "utilization = %d %%, avg_load = %d %%\n",
144 			utilization, data->avg_load);
145 
146 	ret = gk20a_pmu_dvfs_get_cur_state(pmu, &state);
147 	if (ret) {
148 		nv_warn(pmu, "failed to get current state\n");
149 		goto resched;
150 	}
151 
152 	if (gk20a_pmu_dvfs_get_target_state(pmu, &state, data->avg_load)) {
153 		nv_trace(pmu, "set new state to %d\n", state);
154 		gk20a_pmu_dvfs_target(pmu, &state);
155 	}
156 
157 resched:
158 	gk20a_pmu_dvfs_reset_dev_status(pmu);
159 	nvkm_timer_alarm(pmu, 100000000, alarm);
160 }
161 
162 static int
163 gk20a_pmu_fini(struct nvkm_object *object, bool suspend)
164 {
165 	struct gk20a_pmu *pmu = (void *)object;
166 
167 	nvkm_timer_alarm_cancel(pmu, &pmu->alarm);
168 
169 	return nvkm_subdev_fini(&pmu->base.subdev, suspend);
170 }
171 
172 static int
173 gk20a_pmu_init(struct nvkm_object *object)
174 {
175 	struct gk20a_pmu *pmu = (void *)object;
176 	int ret;
177 
178 	ret = nvkm_subdev_init(&pmu->base.subdev);
179 	if (ret)
180 		return ret;
181 
182 	pmu->base.pgob = nvkm_pmu_pgob;
183 
184 	/* init pwr perf counter */
185 	nv_wr32(pmu, 0x10a504 + (BUSY_SLOT * 0x10), 0x00200001);
186 	nv_wr32(pmu, 0x10a50c + (BUSY_SLOT * 0x10), 0x00000002);
187 	nv_wr32(pmu, 0x10a50c + (CLK_SLOT * 0x10), 0x00000003);
188 
189 	nvkm_timer_alarm(pmu, 2000000000, &pmu->alarm);
190 	return ret;
191 }
192 
193 static struct gk20a_pmu_dvfs_data
194 gk20a_dvfs_data= {
195 	.p_load_target = 70,
196 	.p_load_max = 90,
197 	.p_smooth = 1,
198 };
199 
200 static int
201 gk20a_pmu_ctor(struct nvkm_object *parent, struct nvkm_object *engine,
202 	       struct nvkm_oclass *oclass, void *data, u32 size,
203 	       struct nvkm_object **pobject)
204 {
205 	struct gk20a_pmu *pmu;
206 	int ret;
207 
208 	ret = nvkm_pmu_create(parent, engine, oclass, &pmu);
209 	*pobject = nv_object(pmu);
210 	if (ret)
211 		return ret;
212 
213 	pmu->data = &gk20a_dvfs_data;
214 
215 	nvkm_alarm_init(&pmu->alarm, gk20a_pmu_dvfs_work);
216 	return 0;
217 }
218 
219 struct nvkm_oclass *
220 gk20a_pmu_oclass = &(struct nvkm_pmu_impl) {
221 	.base.handle = NV_SUBDEV(PMU, 0xea),
222 	.base.ofuncs = &(struct nvkm_ofuncs) {
223 		.ctor = gk20a_pmu_ctor,
224 		.dtor = _nvkm_pmu_dtor,
225 		.init = gk20a_pmu_init,
226 		.fini = gk20a_pmu_fini,
227 	},
228 }.base;
229