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(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, i);
48
49		opp = dev_pm_opp_find_freq_exact(cpu, opp_freq * MHZ, true);
50		if (IS_ERR(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(cpu, opp_freq * MHZ,
65						new_volt, new_volt, 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(cpuid);
89		if (!cpu)
90			continue;
91
92		opp_table = dev_pm_opp_get_opp_table(cpu);
93		if (IS_ERR(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, sizeof(*asv), GFP_KERNEL);
120	if (!asv)
121		return -ENOMEM;
122
123	asv->chipid_regmap = regmap;
124	asv->dev = dev;
125	ret = regmap_read(asv->chipid_regmap, EXYNOS_CHIPID_REG_PRO_ID,
126			  &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, asv);
139		return 0;
140	}
141
142	cpu_dev = get_cpu_device(0);
143	ret = dev_pm_opp_get_opp_count(cpu_dev);
144	if (ret < 0)
145		return -EPROBE_DEFER;
146
147	ret = of_property_read_u32(dev->of_node, "samsung,asv-bin",
148				   &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