1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2019 Samsung Electronics Co., Ltd.
4 * http://www.samsung.com/
5 * Copyright (c) 2020 Krzysztof Kozlowski <krzk@kernel.org>
6 * Author: Sylwester Nawrocki <s.nawrocki@samsung.com>
7 * Author: Krzysztof Kozlowski <krzk@kernel.org>
8 *
9 * Samsung Exynos SoC Adaptive Supply Voltage support
10 */
11
12 #include <linux/array_size.h>
13 #include <linux/cpu.h>
14 #include <linux/device.h>
15 #include <linux/energy_model.h>
16 #include <linux/errno.h>
17 #include <linux/of.h>
18 #include <linux/pm_opp.h>
19 #include <linux/regmap.h>
20 #include <linux/soc/samsung/exynos-chipid.h>
21
22 #include "exynos-asv.h"
23 #include "exynos5422-asv.h"
24
25 #define MHZ 1000000U
26
exynos_asv_update_cpu_opps(struct exynos_asv * asv,struct device * cpu)27 static int exynos_asv_update_cpu_opps(struct exynos_asv *asv,
28 struct device *cpu)
29 {
30 struct exynos_asv_subsys *subsys = NULL;
31 struct dev_pm_opp *opp;
32 unsigned int opp_freq;
33 int i;
34
35 for (i = 0; i < ARRAY_SIZE(asv->subsys); i++) {
36 if (of_device_is_compatible(cpu->of_node,
37 asv->subsys[i].cpu_dt_compat)) {
38 subsys = &asv->subsys[i];
39 break;
40 }
41 }
42 if (!subsys)
43 return -EINVAL;
44
45 for (i = 0; i < subsys->table.num_rows; i++) {
46 unsigned int new_volt, volt;
47 int ret;
48
49 opp_freq = exynos_asv_opp_get_frequency(subsys, i);
50
51 opp = dev_pm_opp_find_freq_exact(cpu, opp_freq * MHZ, true);
52 if (IS_ERR(opp)) {
53 dev_info(asv->dev, "cpu%d opp%d, freq: %u missing\n",
54 cpu->id, i, opp_freq);
55
56 continue;
57 }
58
59 volt = dev_pm_opp_get_voltage(opp);
60 new_volt = asv->opp_get_voltage(subsys, i, volt);
61 dev_pm_opp_put(opp);
62
63 if (new_volt == volt)
64 continue;
65
66 ret = dev_pm_opp_adjust_voltage(cpu, opp_freq * MHZ,
67 new_volt, new_volt, new_volt);
68 if (ret < 0)
69 dev_err(asv->dev,
70 "Failed to adjust OPP %u Hz/%u uV for cpu%d\n",
71 opp_freq, new_volt, cpu->id);
72 else
73 dev_dbg(asv->dev,
74 "Adjusted OPP %u Hz/%u -> %u uV, cpu%d\n",
75 opp_freq, volt, new_volt, cpu->id);
76 }
77
78 return 0;
79 }
80
exynos_asv_update_opps(struct exynos_asv * asv)81 static int exynos_asv_update_opps(struct exynos_asv *asv)
82 {
83 struct opp_table *last_opp_table = NULL;
84 struct device *cpu;
85 int ret, cpuid;
86
87 for_each_possible_cpu(cpuid) {
88 struct opp_table *opp_table;
89
90 cpu = get_cpu_device(cpuid);
91 if (!cpu)
92 continue;
93
94 opp_table = dev_pm_opp_get_opp_table(cpu);
95 if (IS_ERR(opp_table))
96 continue;
97
98 if (!last_opp_table || opp_table != last_opp_table) {
99 last_opp_table = opp_table;
100
101 ret = exynos_asv_update_cpu_opps(asv, cpu);
102 if (!ret) {
103 /*
104 * Update EM power values since OPP
105 * voltage values may have changed.
106 */
107 em_dev_update_chip_binning(cpu);
108 } else {
109 dev_err(asv->dev, "Couldn't udate OPPs for cpu%d\n",
110 cpuid);
111 }
112 }
113
114 dev_pm_opp_put_opp_table(opp_table);
115 }
116
117 return 0;
118 }
119
exynos_asv_init(struct device * dev,struct regmap * regmap)120 int exynos_asv_init(struct device *dev, struct regmap *regmap)
121 {
122 int (*probe_func)(struct exynos_asv *asv);
123 struct exynos_asv *asv;
124 struct device *cpu_dev;
125 u32 product_id = 0;
126 int ret, i;
127
128 asv = devm_kzalloc(dev, sizeof(*asv), GFP_KERNEL);
129 if (!asv)
130 return -ENOMEM;
131
132 asv->chipid_regmap = regmap;
133 asv->dev = dev;
134 ret = regmap_read(asv->chipid_regmap, EXYNOS_CHIPID_REG_PRO_ID,
135 &product_id);
136 if (ret < 0) {
137 dev_err(dev, "Cannot read revision from ChipID: %d\n", ret);
138 return -ENODEV;
139 }
140
141 switch (product_id & EXYNOS_MASK) {
142 case 0xE5422000:
143 probe_func = exynos5422_asv_init;
144 break;
145 default:
146 dev_dbg(dev, "No ASV support for this SoC\n");
147 devm_kfree(dev, asv);
148 return 0;
149 }
150
151 cpu_dev = get_cpu_device(0);
152 ret = dev_pm_opp_get_opp_count(cpu_dev);
153 if (ret < 0)
154 return -EPROBE_DEFER;
155
156 ret = of_property_read_u32(dev->of_node, "samsung,asv-bin",
157 &asv->of_bin);
158 if (ret < 0)
159 asv->of_bin = -EINVAL;
160
161 for (i = 0; i < ARRAY_SIZE(asv->subsys); i++)
162 asv->subsys[i].asv = asv;
163
164 ret = probe_func(asv);
165 if (ret < 0)
166 return ret;
167
168 return exynos_asv_update_opps(asv);
169 }
170