drivers/soc/samsung/exynos-asv.c

   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
  25 static 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
  79 static 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
 111 int 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 }