1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
|
From 944b041c91f1e1cd762c39c1222f078550149486 Mon Sep 17 00:00:00 2001
From: Jia-Wei Chang <jia-wei.chang@mediatek.com>
Date: Thu, 5 May 2022 19:52:20 +0800
Subject: [PATCH 10/21] cpufreq: mediatek: Refine
mtk_cpufreq_voltage_tracking()
Because the difference of sram and proc should in a range of min_volt_shift
and max_volt_shift. We need to adjust the sram and proc step by step.
We replace VOLT_TOL (voltage tolerance) with the platform data and update the
logic to determine the voltage boundary and invoking regulator_set_voltage.
- Use 'sram_min_volt' and 'sram_max_volt' to determine the voltage boundary
of sram regulator.
- Use (sram_min_volt - min_volt_shift) and 'proc_max_volt' to determine the
voltage boundary of vproc regulator.
Moreover, to prevent infinite loop when tracking voltage, we calculate the
maximum value for each platform data.
We assume min voltage is 0 and tracking target voltage using
min_volt_shift for each iteration.
The retry_max is 3 times of expeted iteration count.
Signed-off-by: Jia-Wei Chang <jia-wei.chang@mediatek.com>
Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
drivers/cpufreq/mediatek-cpufreq.c | 147 ++++++++++-------------------
1 file changed, 51 insertions(+), 96 deletions(-)
--- a/drivers/cpufreq/mediatek-cpufreq.c
+++ b/drivers/cpufreq/mediatek-cpufreq.c
@@ -8,6 +8,7 @@
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/cpumask.h>
+#include <linux/minmax.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
@@ -15,8 +16,6 @@
#include <linux/pm_opp.h>
#include <linux/regulator/consumer.h>
-#define VOLT_TOL (10000)
-
struct mtk_cpufreq_platform_data {
int min_volt_shift;
int max_volt_shift;
@@ -48,6 +47,7 @@ struct mtk_cpu_dvfs_info {
bool need_voltage_tracking;
int pre_vproc;
const struct mtk_cpufreq_platform_data *soc_data;
+ int vtrack_max;
};
static struct platform_device *cpufreq_pdev;
@@ -73,6 +73,7 @@ static int mtk_cpufreq_voltage_tracking(
struct regulator *proc_reg = info->proc_reg;
struct regulator *sram_reg = info->sram_reg;
int pre_vproc, pre_vsram, new_vsram, vsram, vproc, ret;
+ int retry = info->vtrack_max;
pre_vproc = regulator_get_voltage(proc_reg);
if (pre_vproc < 0) {
@@ -80,91 +81,44 @@ static int mtk_cpufreq_voltage_tracking(
"invalid Vproc value: %d\n", pre_vproc);
return pre_vproc;
}
- /* Vsram should not exceed the maximum allowed voltage of SoC. */
- new_vsram = min(new_vproc + soc_data->min_volt_shift,
- soc_data->sram_max_volt);
-
- if (pre_vproc < new_vproc) {
- /*
- * When scaling up voltages, Vsram and Vproc scale up step
- * by step. At each step, set Vsram to (Vproc + 200mV) first,
- * then set Vproc to (Vsram - 100mV).
- * Keep doing it until Vsram and Vproc hit target voltages.
- */
- do {
- pre_vsram = regulator_get_voltage(sram_reg);
- if (pre_vsram < 0) {
- dev_err(info->cpu_dev,
- "invalid Vsram value: %d\n", pre_vsram);
- return pre_vsram;
- }
- pre_vproc = regulator_get_voltage(proc_reg);
- if (pre_vproc < 0) {
- dev_err(info->cpu_dev,
- "invalid Vproc value: %d\n", pre_vproc);
- return pre_vproc;
- }
- vsram = min(new_vsram,
- pre_vproc + soc_data->min_volt_shift);
+ pre_vsram = regulator_get_voltage(sram_reg);
+ if (pre_vsram < 0) {
+ dev_err(info->cpu_dev, "invalid Vsram value: %d\n", pre_vsram);
+ return pre_vsram;
+ }
- if (vsram + VOLT_TOL >= soc_data->sram_max_volt) {
- vsram = soc_data->sram_max_volt;
+ new_vsram = clamp(new_vproc + soc_data->min_volt_shift,
+ soc_data->sram_min_volt, soc_data->sram_max_volt);
+
+ do {
+ if (pre_vproc <= new_vproc) {
+ vsram = clamp(pre_vproc + soc_data->max_volt_shift,
+ soc_data->sram_min_volt, new_vsram);
+ ret = regulator_set_voltage(sram_reg, vsram,
+ soc_data->sram_max_volt);
- /*
- * If the target Vsram hits the maximum voltage,
- * try to set the exact voltage value first.
- */
- ret = regulator_set_voltage(sram_reg, vsram,
- vsram);
- if (ret)
- ret = regulator_set_voltage(sram_reg,
- vsram - VOLT_TOL,
- vsram);
+ if (ret)
+ return ret;
+ if (vsram == soc_data->sram_max_volt ||
+ new_vsram == soc_data->sram_min_volt)
vproc = new_vproc;
- } else {
- ret = regulator_set_voltage(sram_reg, vsram,
- vsram + VOLT_TOL);
-
+ else
vproc = vsram - soc_data->min_volt_shift;
- }
- if (ret)
- return ret;
ret = regulator_set_voltage(proc_reg, vproc,
- vproc + VOLT_TOL);
+ soc_data->proc_max_volt);
if (ret) {
regulator_set_voltage(sram_reg, pre_vsram,
- pre_vsram);
+ soc_data->sram_max_volt);
return ret;
}
- } while (vproc < new_vproc || vsram < new_vsram);
- } else if (pre_vproc > new_vproc) {
- /*
- * When scaling down voltages, Vsram and Vproc scale down step
- * by step. At each step, set Vproc to (Vsram - 200mV) first,
- * then set Vproc to (Vproc + 100mV).
- * Keep doing it until Vsram and Vproc hit target voltages.
- */
- do {
- pre_vproc = regulator_get_voltage(proc_reg);
- if (pre_vproc < 0) {
- dev_err(info->cpu_dev,
- "invalid Vproc value: %d\n", pre_vproc);
- return pre_vproc;
- }
- pre_vsram = regulator_get_voltage(sram_reg);
- if (pre_vsram < 0) {
- dev_err(info->cpu_dev,
- "invalid Vsram value: %d\n", pre_vsram);
- return pre_vsram;
- }
-
+ } else if (pre_vproc > new_vproc) {
vproc = max(new_vproc,
pre_vsram - soc_data->max_volt_shift);
ret = regulator_set_voltage(proc_reg, vproc,
- vproc + VOLT_TOL);
+ soc_data->proc_max_volt);
if (ret)
return ret;
@@ -174,32 +128,24 @@ static int mtk_cpufreq_voltage_tracking(
vsram = max(new_vsram,
vproc + soc_data->min_volt_shift);
- if (vsram + VOLT_TOL >= soc_data->sram_max_volt) {
- vsram = soc_data->sram_max_volt;
-
- /*
- * If the target Vsram hits the maximum voltage,
- * try to set the exact voltage value first.
- */
- ret = regulator_set_voltage(sram_reg, vsram,
- vsram);
- if (ret)
- ret = regulator_set_voltage(sram_reg,
- vsram - VOLT_TOL,
- vsram);
- } else {
- ret = regulator_set_voltage(sram_reg, vsram,
- vsram + VOLT_TOL);
- }
-
+ ret = regulator_set_voltage(sram_reg, vsram,
+ soc_data->sram_max_volt);
if (ret) {
regulator_set_voltage(proc_reg, pre_vproc,
- pre_vproc);
+ soc_data->proc_max_volt);
return ret;
}
- } while (vproc > new_vproc + VOLT_TOL ||
- vsram > new_vsram + VOLT_TOL);
- }
+ }
+
+ pre_vproc = vproc;
+ pre_vsram = vsram;
+
+ if (--retry < 0) {
+ dev_err(info->cpu_dev,
+ "over loop count, failed to set voltage\n");
+ return -EINVAL;
+ }
+ } while (vproc != new_vproc || vsram != new_vsram);
return 0;
}
@@ -261,8 +207,8 @@ static int mtk_cpufreq_set_target(struct
* If the new voltage or the intermediate voltage is higher than the
* current voltage, scale up voltage first.
*/
- target_vproc = (inter_vproc > vproc) ? inter_vproc : vproc;
- if (pre_vproc < target_vproc) {
+ target_vproc = max(inter_vproc, vproc);
+ if (pre_vproc <= target_vproc) {
ret = mtk_cpufreq_set_voltage(info, target_vproc);
if (ret) {
dev_err(cpu_dev,
@@ -417,6 +363,15 @@ static int mtk_cpu_dvfs_info_init(struct
*/
info->need_voltage_tracking = (info->sram_reg != NULL);
+ /*
+ * We assume min voltage is 0 and tracking target voltage using
+ * min_volt_shift for each iteration.
+ * The vtrack_max is 3 times of expeted iteration count.
+ */
+ info->vtrack_max = 3 * DIV_ROUND_UP(max(info->soc_data->sram_max_volt,
+ info->soc_data->proc_max_volt),
+ info->soc_data->min_volt_shift);
+
return 0;
out_disable_inter_clock:
|
