drivers/cpufreq/qcom-cpufreq-nvmem.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-nvmem 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/of_device.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/pm_domain.h>
  28 #include <linux/pm_opp.h>
  29 #include <linux/slab.h>
  30 #include <linux/soc/qcom/smem.h>
  31
  32 #define MSM_ID_SMEM     137
  33
  34 enum _msm_id {
  35         MSM8996V3 = 0xF6ul,
  36         APQ8096V3 = 0x123ul,
  37         MSM8996SG = 0x131ul,
  38         APQ8096SG = 0x138ul,
  39 };
  40
  41 enum _msm8996_version {
  42         MSM8996_V3,
  43         MSM8996_SG,
  44         NUM_OF_MSM8996_VERSIONS,
  45 };
  46
  47 struct qcom_cpufreq_drv;
  48
  49 struct qcom_cpufreq_match_data {
  50         int (*get_version)(struct device *cpu_dev,
  51                            struct nvmem_cell *speedbin_nvmem,
  52                            struct qcom_cpufreq_drv *drv);
  53         const char **genpd_names;
  54 };
  55
  56 struct qcom_cpufreq_drv {
  57         struct opp_table **opp_tables;
  58         struct opp_table **genpd_opp_tables;
  59         u32 versions;
  60         const struct qcom_cpufreq_match_data *data;
  61 };
  62
  63 static struct platform_device *cpufreq_dt_pdev, *cpufreq_pdev;
  64
  65 static enum _msm8996_version qcom_cpufreq_get_msm_id(void)
  66 {
  67         size_t len;
  68         u32 *msm_id;
  69         enum _msm8996_version version;
  70
  71         msm_id = qcom_smem_get(QCOM_SMEM_HOST_ANY, MSM_ID_SMEM, &len);
  72         if (IS_ERR(msm_id))
  73                 return NUM_OF_MSM8996_VERSIONS;
  74
  75         /* The first 4 bytes are format, next to them is the actual msm-id */
  76         msm_id++;
  77
  78         switch ((enum _msm_id)*msm_id) {
  79         case MSM8996V3:
  80         case APQ8096V3:
  81                 version = MSM8996_V3;
  82                 break;
  83         case MSM8996SG:
  84         case APQ8096SG:
  85                 version = MSM8996_SG;
  86                 break;
  87         default:
  88                 version = NUM_OF_MSM8996_VERSIONS;
  89         }
  90
  91         return version;
  92 }
  93
  94 static int qcom_cpufreq_kryo_name_version(struct device *cpu_dev,
  95                                           struct nvmem_cell *speedbin_nvmem,
  96                                           struct qcom_cpufreq_drv *drv)
  97 {
  98         size_t len;
  99         u8 *speedbin;
 100         enum _msm8996_version msm8996_version;
 101
 102         msm8996_version = qcom_cpufreq_get_msm_id();
 103         if (NUM_OF_MSM8996_VERSIONS == msm8996_version) {
 104                 dev_err(cpu_dev, "Not Snapdragon 820/821!");
 105                 return -ENODEV;
 106         }
 107
 108         speedbin = nvmem_cell_read(speedbin_nvmem, &len);
 109         if (IS_ERR(speedbin))
 110                 return PTR_ERR(speedbin);
 111
 112         switch (msm8996_version) {
 113         case MSM8996_V3:
 114                 drv->versions = 1 << (unsigned int)(*speedbin);
 115                 break;
 116         case MSM8996_SG:
 117                 drv->versions = 1 << ((unsigned int)(*speedbin) + 4);
 118                 break;
 119         default:
 120                 BUG();
 121                 break;
 122         }
 123
 124         kfree(speedbin);
 125         return 0;
 126 }
 127
 128 static const struct qcom_cpufreq_match_data match_data_kryo = {
 129         .get_version = qcom_cpufreq_kryo_name_version,
 130 };
 131
 132 static const char *qcs404_genpd_names[] = { "cpr", NULL };
 133
 134 static const struct qcom_cpufreq_match_data match_data_qcs404 = {
 135         .genpd_names = qcs404_genpd_names,
 136 };
 137
 138 static int qcom_cpufreq_probe(struct platform_device *pdev)
 139 {
 140         struct qcom_cpufreq_drv *drv;
 141         struct nvmem_cell *speedbin_nvmem;
 142         struct device_node *np;
 143         struct device *cpu_dev;
 144         unsigned cpu;
 145         const struct of_device_id *match;
 146         int ret;
 147
 148         cpu_dev = get_cpu_device(0);
 149         if (!cpu_dev)
 150                 return -ENODEV;
 151
 152         np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
 153         if (!np)
 154                 return -ENOENT;
 155
 156         ret = of_device_is_compatible(np, "operating-points-v2-kryo-cpu");
 157         if (!ret) {
 158                 of_node_put(np);
 159                 return -ENOENT;
 160         }
 161
 162         drv = kzalloc(sizeof(*drv), GFP_KERNEL);
 163         if (!drv)
 164                 return -ENOMEM;
 165
 166         match = pdev->dev.platform_data;
 167         drv->data = match->data;
 168         if (!drv->data) {
 169                 ret = -ENODEV;
 170                 goto free_drv;
 171         }
 172
 173         if (drv->data->get_version) {
 174                 speedbin_nvmem = of_nvmem_cell_get(np, NULL);
 175                 if (IS_ERR(speedbin_nvmem)) {
 176                         if (PTR_ERR(speedbin_nvmem) != -EPROBE_DEFER)
 177                                 dev_err(cpu_dev,
 178                                         "Could not get nvmem cell: %ld\n",
 179                                         PTR_ERR(speedbin_nvmem));
 180                         ret = PTR_ERR(speedbin_nvmem);
 181                         goto free_drv;
 182                 }
 183
 184                 ret = drv->data->get_version(cpu_dev, speedbin_nvmem, drv);
 185                 if (ret) {
 186                         nvmem_cell_put(speedbin_nvmem);
 187                         goto free_drv;
 188                 }
 189                 nvmem_cell_put(speedbin_nvmem);
 190         }
 191         of_node_put(np);
 192
 193         drv->opp_tables = kcalloc(num_possible_cpus(), sizeof(*drv->opp_tables),
 194                                   GFP_KERNEL);
 195         if (!drv->opp_tables) {
 196                 ret = -ENOMEM;
 197                 goto free_drv;
 198         }
 199
 200         drv->genpd_opp_tables = kcalloc(num_possible_cpus(),
 201                                         sizeof(*drv->genpd_opp_tables),
 202                                         GFP_KERNEL);
 203         if (!drv->genpd_opp_tables) {
 204                 ret = -ENOMEM;
 205                 goto free_opp;
 206         }
 207
 208         for_each_possible_cpu(cpu) {
 209                 cpu_dev = get_cpu_device(cpu);
 210                 if (NULL == cpu_dev) {
 211                         ret = -ENODEV;
 212                         goto free_genpd_opp;
 213                 }
 214
 215                 if (drv->data->get_version) {
 216                         drv->opp_tables[cpu] =
 217                                 dev_pm_opp_set_supported_hw(cpu_dev,
 218                                                             &drv->versions, 1);
 219                         if (IS_ERR(drv->opp_tables[cpu])) {
 220                                 ret = PTR_ERR(drv->opp_tables[cpu]);
 221                                 dev_err(cpu_dev,
 222                                         "Failed to set supported hardware\n");
 223                                 goto free_genpd_opp;
 224                         }
 225                 }
 226
 227                 if (drv->data->genpd_names) {
 228                         drv->genpd_opp_tables[cpu] =
 229                                 dev_pm_opp_attach_genpd(cpu_dev,
 230                                                         drv->data->genpd_names,
 231                                                         NULL);
 232                         if (IS_ERR(drv->genpd_opp_tables[cpu])) {
 233                                 ret = PTR_ERR(drv->genpd_opp_tables[cpu]);
 234                                 if (ret != -EPROBE_DEFER)
 235                                         dev_err(cpu_dev,
 236                                                 "Could not attach to pm_domain: %d\n",
 237                                                 ret);
 238                                 goto free_genpd_opp;
 239                         }
 240                 }
 241         }
 242
 243         cpufreq_dt_pdev = platform_device_register_simple("cpufreq-dt", -1,
 244                                                           NULL, 0);
 245         if (!IS_ERR(cpufreq_dt_pdev)) {
 246                 platform_set_drvdata(pdev, drv);
 247                 return 0;
 248         }
 249
 250         ret = PTR_ERR(cpufreq_dt_pdev);
 251         dev_err(cpu_dev, "Failed to register platform device\n");
 252
 253 free_genpd_opp:
 254         for_each_possible_cpu(cpu) {
 255                 if (IS_ERR_OR_NULL(drv->genpd_opp_tables[cpu]))
 256                         break;
 257                 dev_pm_opp_detach_genpd(drv->genpd_opp_tables[cpu]);
 258         }
 259         kfree(drv->genpd_opp_tables);
 260 free_opp:
 261         for_each_possible_cpu(cpu) {
 262                 if (IS_ERR_OR_NULL(drv->opp_tables[cpu]))
 263                         break;
 264                 dev_pm_opp_put_supported_hw(drv->opp_tables[cpu]);
 265         }
 266         kfree(drv->opp_tables);
 267 free_drv:
 268         kfree(drv);
 269
 270         return ret;
 271 }
 272
 273 static int qcom_cpufreq_remove(struct platform_device *pdev)
 274 {
 275         struct qcom_cpufreq_drv *drv = platform_get_drvdata(pdev);
 276         unsigned int cpu;
 277
 278         platform_device_unregister(cpufreq_dt_pdev);
 279
 280         for_each_possible_cpu(cpu) {
 281                 if (drv->opp_tables[cpu])
 282                         dev_pm_opp_put_supported_hw(drv->opp_tables[cpu]);
 283                 if (drv->genpd_opp_tables[cpu])
 284                         dev_pm_opp_detach_genpd(drv->genpd_opp_tables[cpu]);
 285         }
 286
 287         kfree(drv->opp_tables);
 288         kfree(drv->genpd_opp_tables);
 289         kfree(drv);
 290
 291         return 0;
 292 }
 293
 294 static struct platform_driver qcom_cpufreq_driver = {
 295         .probe = qcom_cpufreq_probe,
 296         .remove = qcom_cpufreq_remove,
 297         .driver = {
 298                 .name = "qcom-cpufreq-nvmem",
 299         },
 300 };
 301
 302 static const struct of_device_id qcom_cpufreq_match_list[] __initconst = {
 303         { .compatible = "qcom,apq8096", .data = &match_data_kryo },
 304         { .compatible = "qcom,msm8996", .data = &match_data_kryo },
 305         { .compatible = "qcom,qcs404", .data = &match_data_qcs404 },
 306         {},
 307 };
 308
 309 /*
 310  * Since the driver depends on smem and nvmem drivers, which may
 311  * return EPROBE_DEFER, all the real activity is done in the probe,
 312  * which may be defered as well. The init here is only registering
 313  * the driver and the platform device.
 314  */
 315 static int __init qcom_cpufreq_init(void)
 316 {
 317         struct device_node *np = of_find_node_by_path("/");
 318         const struct of_device_id *match;
 319         int ret;
 320
 321         if (!np)
 322                 return -ENODEV;
 323
 324         match = of_match_node(qcom_cpufreq_match_list, np);
 325         of_node_put(np);
 326         if (!match)
 327                 return -ENODEV;
 328
 329         ret = platform_driver_register(&qcom_cpufreq_driver);
 330         if (unlikely(ret < 0))
 331                 return ret;
 332
 333         cpufreq_pdev = platform_device_register_data(NULL, "qcom-cpufreq-nvmem",
 334                                                      -1, match, sizeof(*match));
 335         ret = PTR_ERR_OR_ZERO(cpufreq_pdev);
 336         if (0 == ret)
 337                 return 0;
 338
 339         platform_driver_unregister(&qcom_cpufreq_driver);
 340         return ret;
 341 }
 342 module_init(qcom_cpufreq_init);
 343
 344 static void __exit qcom_cpufreq_exit(void)
 345 {
 346         platform_device_unregister(cpufreq_pdev);
 347         platform_driver_unregister(&qcom_cpufreq_driver);
 348 }
 349 module_exit(qcom_cpufreq_exit);
 350
 351 MODULE_DESCRIPTION("Qualcomm Technologies, Inc. CPUfreq driver");
 352 MODULE_LICENSE("GPL v2");