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}