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  * Author: Sylwester Nawrocki <s.nawrocki@samsung.com>
   6  *
   7  * Samsung Exynos SoC Adaptive Supply Voltage support
   8  */
   9
  10 #include <linux/cpu.h>
  11 #include <linux/device.h>
  12 #include <linux/errno.h>
  13 #include <linux/init.h>
  14 #include <linux/mfd/syscon.h>
  15 #include <linux/module.h>
  16 #include <linux/of.h>
  17 #include <linux/of_device.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/pm_opp.h>
  20 #include <linux/regmap.h>
  21 #include <linux/soc/samsung/exynos-chipid.h>
  22
  23 #include "exynos-asv.h"
  24 #include "exynos5422-asv.h"
  25
  26 #define MHZ 1000000U
  27
  28 static int exynos_asv_update_cpu_opps(struct exynos_asv *asv,
  29                                       struct device *cpu)
  30 {
  31         struct exynos_asv_subsys *subsys = NULL;
  32         struct dev_pm_opp *opp;
  33         unsigned int opp_freq;
  34         int i;
  35
  36         for (i = 0; i < ARRAY_SIZE(asv->subsys); i++) {
  37                 if (of_device_is_compatible(cpu->of_node,
  38                                             asv->subsys[i].cpu_dt_compat)) {
  39                         subsys = &asv->subsys[i];
  40                         break;
  41                 }
  42         }
  43         if (!subsys)
  44                 return -EINVAL;
  45
  46         for (i = 0; i < subsys->table.num_rows; i++) {
  47                 unsigned int new_volt, volt;
  48                 int ret;
  49
  50                 opp_freq = exynos_asv_opp_get_frequency(subsys, i);
  51
  52                 opp = dev_pm_opp_find_freq_exact(cpu, opp_freq * MHZ, true);
  53                 if (IS_ERR(opp)) {
  54                         dev_info(asv->dev, "cpu%d opp%d, freq: %u missing\n",
  55                                  cpu->id, i, opp_freq);
  56
  57                         continue;
  58                 }
  59
  60                 volt = dev_pm_opp_get_voltage(opp);
  61                 new_volt = asv->opp_get_voltage(subsys, i, volt);
  62                 dev_pm_opp_put(opp);
  63
  64                 if (new_volt == volt)
  65                         continue;
  66
  67                 ret = dev_pm_opp_adjust_voltage(cpu, opp_freq * MHZ,
  68                                                 new_volt, new_volt, new_volt);
  69                 if (ret < 0)
  70                         dev_err(asv->dev,
  71                                 "Failed to adjust OPP %u Hz/%u uV for cpu%d\n",
  72                                 opp_freq, new_volt, cpu->id);
  73                 else
  74                         dev_dbg(asv->dev,
  75                                 "Adjusted OPP %u Hz/%u -> %u uV, cpu%d\n",
  76                                 opp_freq, volt, new_volt, cpu->id);
  77         }
  78
  79         return 0;
  80 }
  81
  82 static int exynos_asv_update_opps(struct exynos_asv *asv)
  83 {
  84         struct opp_table *last_opp_table = NULL;
  85         struct device *cpu;
  86         int ret, cpuid;
  87
  88         for_each_possible_cpu(cpuid) {
  89                 struct opp_table *opp_table;
  90
  91                 cpu = get_cpu_device(cpuid);
  92                 if (!cpu)
  93                         continue;
  94
  95                 opp_table = dev_pm_opp_get_opp_table(cpu);
  96                 if (IS_ERR(opp_table))
  97                         continue;
  98
  99                 if (!last_opp_table || opp_table != last_opp_table) {
 100                         last_opp_table = opp_table;
 101
 102                         ret = exynos_asv_update_cpu_opps(asv, cpu);
 103                         if (ret < 0)
 104                                 dev_err(asv->dev, "Couldn't udate OPPs for cpu%d\n",
 105                                         cpuid);
 106                 }
 107
 108                 dev_pm_opp_put_opp_table(opp_table);
 109         }
 110
 111         return  0;
 112 }
 113
 114 static int exynos_asv_probe(struct platform_device *pdev)
 115 {
 116         int (*probe_func)(struct exynos_asv *asv);
 117         struct exynos_asv *asv;
 118         struct device *cpu_dev;
 119         u32 product_id = 0;
 120         int ret, i;
 121
 122         cpu_dev = get_cpu_device(0);
 123         ret = dev_pm_opp_get_opp_count(cpu_dev);
 124         if (ret < 0)
 125                 return -EPROBE_DEFER;
 126
 127         asv = devm_kzalloc(&pdev->dev, sizeof(*asv), GFP_KERNEL);
 128         if (!asv)
 129                 return -ENOMEM;
 130
 131         asv->chipid_regmap = device_node_to_regmap(pdev->dev.of_node);
 132         if (IS_ERR(asv->chipid_regmap)) {
 133                 dev_err(&pdev->dev, "Could not find syscon regmap\n");
 134                 return PTR_ERR(asv->chipid_regmap);
 135         }
 136
 137         regmap_read(asv->chipid_regmap, EXYNOS_CHIPID_REG_PRO_ID, &product_id);
 138
 139         switch (product_id & EXYNOS_MASK) {
 140         case 0xE5422000:
 141                 probe_func = exynos5422_asv_init;
 142                 break;
 143         default:
 144                 return -ENODEV;
 145         }
 146
 147         ret = of_property_read_u32(pdev->dev.of_node, "samsung,asv-bin",
 148                                    &asv->of_bin);
 149         if (ret < 0)
 150                 asv->of_bin = -EINVAL;
 151
 152         asv->dev = &pdev->dev;
 153         dev_set_drvdata(&pdev->dev, asv);
 154
 155         for (i = 0; i < ARRAY_SIZE(asv->subsys); i++)
 156                 asv->subsys[i].asv = asv;
 157
 158         ret = probe_func(asv);
 159         if (ret < 0)
 160                 return ret;
 161
 162         return exynos_asv_update_opps(asv);
 163 }
 164
 165 static const struct of_device_id exynos_asv_of_device_ids[] = {
 166         { .compatible = "samsung,exynos4210-chipid" },
 167         {}
 168 };
 169
 170 static struct platform_driver exynos_asv_driver = {
 171         .driver = {
 172                 .name = "exynos-asv",
 173                 .of_match_table = exynos_asv_of_device_ids,
 174         },
 175         .probe  = exynos_asv_probe,
 176 };
 177 module_platform_driver(exynos_asv_driver);