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 struct platform_device *cpufreq_dt_pdev, *kryo_cpufreq_pdev;
  46
  47 static enum _msm8996_version qcom_cpufreq_kryo_get_msm_id(void)
  48 {
  49         size_t len;
  50         u32 *msm_id;
  51         enum _msm8996_version version;
  52
  53         msm_id = qcom_smem_get(QCOM_SMEM_HOST_ANY, MSM_ID_SMEM, &len);
  54         if (IS_ERR(msm_id))
  55                 return NUM_OF_MSM8996_VERSIONS;
  56
  57         /* The first 4 bytes are format, next to them is the actual msm-id */
  58         msm_id++;
  59
  60         switch ((enum _msm_id)*msm_id) {
  61         case MSM8996V3:
  62         case APQ8096V3:
  63                 version = MSM8996_V3;
  64                 break;
  65         case MSM8996SG:
  66         case APQ8096SG:
  67                 version = MSM8996_SG;
  68                 break;
  69         default:
  70                 version = NUM_OF_MSM8996_VERSIONS;
  71         }
  72
  73         return version;
  74 }
  75
  76 static int qcom_cpufreq_kryo_probe(struct platform_device *pdev)
  77 {
  78         struct opp_table **opp_tables;
  79         enum _msm8996_version msm8996_version;
  80         struct nvmem_cell *speedbin_nvmem;
  81         struct device_node *np;
  82         struct device *cpu_dev;
  83         unsigned cpu;
  84         u8 *speedbin;
  85         u32 versions;
  86         size_t len;
  87         int ret;
  88
  89         cpu_dev = get_cpu_device(0);
  90         if (!cpu_dev)
  91                 return -ENODEV;
  92
  93         msm8996_version = qcom_cpufreq_kryo_get_msm_id();
  94         if (NUM_OF_MSM8996_VERSIONS == msm8996_version) {
  95                 dev_err(cpu_dev, "Not Snapdragon 820/821!");
  96                 return -ENODEV;
  97         }
  98
  99         np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
 100         if (!np)
 101                 return -ENOENT;
 102
 103         ret = of_device_is_compatible(np, "operating-points-v2-kryo-cpu");
 104         if (!ret) {
 105                 of_node_put(np);
 106                 return -ENOENT;
 107         }
 108
 109         speedbin_nvmem = of_nvmem_cell_get(np, NULL);
 110         of_node_put(np);
 111         if (IS_ERR(speedbin_nvmem)) {
 112                 if (PTR_ERR(speedbin_nvmem) != -EPROBE_DEFER)
 113                         dev_err(cpu_dev, "Could not get nvmem cell: %ld\n",
 114                                 PTR_ERR(speedbin_nvmem));
 115                 return PTR_ERR(speedbin_nvmem);
 116         }
 117
 118         speedbin = nvmem_cell_read(speedbin_nvmem, &len);
 119         nvmem_cell_put(speedbin_nvmem);
 120         if (IS_ERR(speedbin))
 121                 return PTR_ERR(speedbin);
 122
 123         switch (msm8996_version) {
 124         case MSM8996_V3:
 125                 versions = 1 << (unsigned int)(*speedbin);
 126                 break;
 127         case MSM8996_SG:
 128                 versions = 1 << ((unsigned int)(*speedbin) + 4);
 129                 break;
 130         default:
 131                 BUG();
 132                 break;
 133         }
 134         kfree(speedbin);
 135
 136         opp_tables = kcalloc(num_possible_cpus(), sizeof(*opp_tables), GFP_KERNEL);
 137         if (!opp_tables)
 138                 return -ENOMEM;
 139
 140         for_each_possible_cpu(cpu) {
 141                 cpu_dev = get_cpu_device(cpu);
 142                 if (NULL == cpu_dev) {
 143                         ret = -ENODEV;
 144                         goto free_opp;
 145                 }
 146
 147                 opp_tables[cpu] = dev_pm_opp_set_supported_hw(cpu_dev,
 148                                                               &versions, 1);
 149                 if (IS_ERR(opp_tables[cpu])) {
 150                         ret = PTR_ERR(opp_tables[cpu]);
 151                         dev_err(cpu_dev, "Failed to set supported hardware\n");
 152                         goto free_opp;
 153                 }
 154         }
 155
 156         cpufreq_dt_pdev = platform_device_register_simple("cpufreq-dt", -1,
 157                                                           NULL, 0);
 158         if (!IS_ERR(cpufreq_dt_pdev)) {
 159                 platform_set_drvdata(pdev, opp_tables);
 160                 return 0;
 161         }
 162
 163         ret = PTR_ERR(cpufreq_dt_pdev);
 164         dev_err(cpu_dev, "Failed to register platform device\n");
 165
 166 free_opp:
 167         for_each_possible_cpu(cpu) {
 168                 if (IS_ERR_OR_NULL(opp_tables[cpu]))
 169                         break;
 170                 dev_pm_opp_put_supported_hw(opp_tables[cpu]);
 171         }
 172         kfree(opp_tables);
 173
 174         return ret;
 175 }
 176
 177 static int qcom_cpufreq_kryo_remove(struct platform_device *pdev)
 178 {
 179         struct opp_table **opp_tables = platform_get_drvdata(pdev);
 180         unsigned int cpu;
 181
 182         platform_device_unregister(cpufreq_dt_pdev);
 183
 184         for_each_possible_cpu(cpu)
 185                 dev_pm_opp_put_supported_hw(opp_tables[cpu]);
 186
 187         kfree(opp_tables);
 188
 189         return 0;
 190 }
 191
 192 static struct platform_driver qcom_cpufreq_kryo_driver = {
 193         .probe = qcom_cpufreq_kryo_probe,
 194         .remove = qcom_cpufreq_kryo_remove,
 195         .driver = {
 196                 .name = "qcom-cpufreq-kryo",
 197         },
 198 };
 199
 200 static const struct of_device_id qcom_cpufreq_kryo_match_list[] __initconst = {
 201         { .compatible = "qcom,apq8096", },
 202         { .compatible = "qcom,msm8996", },
 203         {}
 204 };
 205
 206 /*
 207  * Since the driver depends on smem and nvmem drivers, which may
 208  * return EPROBE_DEFER, all the real activity is done in the probe,
 209  * which may be defered as well. The init here is only registering
 210  * the driver and the platform device.
 211  */
 212 static int __init qcom_cpufreq_kryo_init(void)
 213 {
 214         struct device_node *np = of_find_node_by_path("/");
 215         const struct of_device_id *match;
 216         int ret;
 217
 218         if (!np)
 219                 return -ENODEV;
 220
 221         match = of_match_node(qcom_cpufreq_kryo_match_list, np);
 222         of_node_put(np);
 223         if (!match)
 224                 return -ENODEV;
 225
 226         ret = platform_driver_register(&qcom_cpufreq_kryo_driver);
 227         if (unlikely(ret < 0))
 228                 return ret;
 229
 230         kryo_cpufreq_pdev = platform_device_register_simple(
 231                 "qcom-cpufreq-kryo", -1, NULL, 0);
 232         ret = PTR_ERR_OR_ZERO(kryo_cpufreq_pdev);
 233         if (0 == ret)
 234                 return 0;
 235
 236         platform_driver_unregister(&qcom_cpufreq_kryo_driver);
 237         return ret;
 238 }
 239 module_init(qcom_cpufreq_kryo_init);
 240
 241 static void __exit qcom_cpufreq_kryo_exit(void)
 242 {
 243         platform_device_unregister(kryo_cpufreq_pdev);
 244         platform_driver_unregister(&qcom_cpufreq_kryo_driver);
 245 }
 246 module_exit(qcom_cpufreq_kryo_exit);
 247
 248 MODULE_DESCRIPTION("Qualcomm Technologies, Inc. Kryo CPUfreq driver");
 249 MODULE_LICENSE("GPL v2");