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| 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"); |
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