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

source code of linux/drivers/soc/samsung/exynos-asv.c