drivers/cpufreq/qcom-cpufreq-kryo.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2018, The Linux Foundation. All rights reserved.
   4  */
   5
   6 /*
   7  * In Certain QCOM SoCs like apq8096 and msm8996 that have KRYO processors,
   8  * the CPU frequency subset and voltage value of each OPP varies
   9  * based on the silicon variant in use. Qualcomm Process Voltage Scaling Tables
  10  * defines the voltage and frequency value based on the msm-id in SMEM
  11  * and speedbin blown in the efuse combination.
  12  * The qcom-cpufreq-kryo driver reads the msm-id and efuse value from the SoC
  13  * to provide the OPP framework with required information.
  14  * This is used to determine the voltage and frequency value for each OPP of
  15  * operating-points-v2 table when it is parsed by the OPP framework.
  16  */
  17
  18 #include <linux/cpu.h>
  19 #include <linux/err.h>
  20 #include <linux/init.h>
  21 #include <linux/kernel.h>
  22 #include <linux/module.h>
  23 #include <linux/nvmem-consumer.h>
  24 #include <linux/of.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/pm_opp.h>
  27 #include <linux/slab.h>
  28 #include <linux/soc/qcom/smem.h>
  29
  30 #define MSM_ID_SMEM     137
  31
  32 enum _msm_id {
  33         MSM8996V3 = 0xF6ul,
  34         APQ8096V3 = 0x123ul,
  35         MSM8996SG = 0x131ul,
  36         APQ8096SG = 0x138ul,
  37 };
  38
  39 enum _msm8996_version {
  40         MSM8996_V3,
  41         MSM8996_SG,
  42         NUM_OF_MSM8996_VERSIONS,
  43 };
  44
  45 static enum _msm8996_version __init qcom_cpufreq_kryo_get_msm_id(void)
  46 {
  47         size_t len;
  48         u32 *msm_id;
  49         enum _msm8996_version version;
  50
  51         msm_id = qcom_smem_get(QCOM_SMEM_HOST_ANY, MSM_ID_SMEM, &len);
  52         if (IS_ERR(msm_id))
  53                 return NUM_OF_MSM8996_VERSIONS;
  54
  55         /* The first 4 bytes are format, next to them is the actual msm-id */
  56         msm_id++;
  57
  58         switch ((enum _msm_id)*msm_id) {
  59         case MSM8996V3:
  60         case APQ8096V3:
  61                 version = MSM8996_V3;
  62                 break;
  63         case MSM8996SG:
  64         case APQ8096SG:
  65                 version = MSM8996_SG;
  66                 break;
  67         default:
  68                 version = NUM_OF_MSM8996_VERSIONS;
  69         }
  70
  71         return version;
  72 }
  73
  74 static int qcom_cpufreq_kryo_probe(struct platform_device *pdev)
  75 {
  76         struct opp_table *opp_tables[NR_CPUS] = {0};
  77         struct platform_device *cpufreq_dt_pdev;
  78         enum _msm8996_version msm8996_version;
  79         struct nvmem_cell *speedbin_nvmem;
  80         struct device_node *np;
  81         struct device *cpu_dev;
  82         unsigned cpu;
  83         u8 *speedbin;
  84         u32 versions;
  85         size_t len;
  86         int ret;
  87
  88         cpu_dev = get_cpu_device(0);
  89         if (NULL == cpu_dev)
  90                 ret = -ENODEV;
  91
  92         msm8996_version = qcom_cpufreq_kryo_get_msm_id();
  93         if (NUM_OF_MSM8996_VERSIONS == msm8996_version) {
  94                 dev_err(cpu_dev, "Not Snapdragon 820/821!");
  95                 return -ENODEV;
  96         }
  97
  98         np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
  99         if (IS_ERR(np))
 100                 return PTR_ERR(np);
 101
 102         ret = of_device_is_compatible(np, "operating-points-v2-kryo-cpu");
 103         if (!ret) {
 104                 of_node_put(np);
 105                 return -ENOENT;
 106         }
 107
 108         speedbin_nvmem = of_nvmem_cell_get(np, NULL);
 109         of_node_put(np);
 110         if (IS_ERR(speedbin_nvmem)) {
 111                 dev_err(cpu_dev, "Could not get nvmem cell: %ld\n",
 112                         PTR_ERR(speedbin_nvmem));
 113                 return PTR_ERR(speedbin_nvmem);
 114         }
 115
 116         speedbin = nvmem_cell_read(speedbin_nvmem, &len);
 117         nvmem_cell_put(speedbin_nvmem);
 118
 119         switch (msm8996_version) {
 120         case MSM8996_V3:
 121                 versions = 1 << (unsigned int)(*speedbin);
 122                 break;
 123         case MSM8996_SG:
 124                 versions = 1 << ((unsigned int)(*speedbin) + 4);
 125                 break;
 126         default:
 127                 BUG();
 128                 break;
 129         }
 130
 131         for_each_possible_cpu(cpu) {
 132                 cpu_dev = get_cpu_device(cpu);
 133                 if (NULL == cpu_dev) {
 134                         ret = -ENODEV;
 135                         goto free_opp;
 136                 }
 137
 138                 opp_tables[cpu] = dev_pm_opp_set_supported_hw(cpu_dev,
 139                                                               &versions, 1);
 140                 if (IS_ERR(opp_tables[cpu])) {
 141                         ret = PTR_ERR(opp_tables[cpu]);
 142                         dev_err(cpu_dev, "Failed to set supported hardware\n");
 143                         goto free_opp;
 144                 }
 145         }
 146
 147         cpufreq_dt_pdev = platform_device_register_simple("cpufreq-dt", -1,
 148                                                           NULL, 0);
 149         if (!IS_ERR(cpufreq_dt_pdev))
 150                 return 0;
 151
 152         ret = PTR_ERR(cpufreq_dt_pdev);
 153         dev_err(cpu_dev, "Failed to register platform device\n");
 154
 155 free_opp:
 156         for_each_possible_cpu(cpu) {
 157                 if (IS_ERR_OR_NULL(opp_tables[cpu]))
 158                         break;
 159                 dev_pm_opp_put_supported_hw(opp_tables[cpu]);
 160         }
 161
 162         return ret;
 163 }
 164
 165 static struct platform_driver qcom_cpufreq_kryo_driver = {
 166         .probe = qcom_cpufreq_kryo_probe,
 167         .driver = {
 168                 .name = "qcom-cpufreq-kryo",
 169         },
 170 };
 171
 172 static const struct of_device_id qcom_cpufreq_kryo_match_list[] __initconst = {
 173         { .compatible = "qcom,apq8096", },
 174         { .compatible = "qcom,msm8996", },
 175 };
 176
 177 /*
 178  * Since the driver depends on smem and nvmem drivers, which may
 179  * return EPROBE_DEFER, all the real activity is done in the probe,
 180  * which may be defered as well. The init here is only registering
 181  * the driver and the platform device.
 182  */
 183 static int __init qcom_cpufreq_kryo_init(void)
 184 {
 185         struct device_node *np = of_find_node_by_path("/");
 186         const struct of_device_id *match;
 187         int ret;
 188
 189         if (!np)
 190                 return -ENODEV;
 191
 192         match = of_match_node(qcom_cpufreq_kryo_match_list, np);
 193         of_node_put(np);
 194         if (!match)
 195                 return -ENODEV;
 196
 197         ret = platform_driver_register(&qcom_cpufreq_kryo_driver);
 198         if (unlikely(ret < 0))
 199                 return ret;
 200
 201         ret = PTR_ERR_OR_ZERO(platform_device_register_simple(
 202                 "qcom-cpufreq-kryo", -1, NULL, 0));
 203         if (0 == ret)
 204                 return 0;
 205
 206         platform_driver_unregister(&qcom_cpufreq_kryo_driver);
 207         return ret;
 208 }
 209 module_init(qcom_cpufreq_kryo_init);
 210
 211 MODULE_DESCRIPTION("Qualcomm Technologies, Inc. Kryo CPUfreq driver");
 212 MODULE_LICENSE("GPL v2");