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