1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (c) 2018, The Linux Foundation. All rights reserved.
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.
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>
25 #include <linux/platform_device.h>
26 #include <linux/pm_opp.h>
27 #include <linux/slab.h>
28 #include <linux/soc/qcom/smem.h>
30 #define MSM_ID_SMEM 137
39 enum _msm8996_version {
42 NUM_OF_MSM8996_VERSIONS,
45 static enum _msm8996_version __init qcom_cpufreq_kryo_get_msm_id(void)
49 enum _msm8996_version version;
51 msm_id = qcom_smem_get(QCOM_SMEM_HOST_ANY, MSM_ID_SMEM, &len);
53 return NUM_OF_MSM8996_VERSIONS;
55 /* The first 4 bytes are format, next to them is the actual msm-id */
58 switch ((enum _msm_id)*msm_id) {
68 version = NUM_OF_MSM8996_VERSIONS;
74 static int qcom_cpufreq_kryo_probe(struct platform_device *pdev)
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;
88 cpu_dev = get_cpu_device(0);
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!");
98 np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
102 ret = of_device_is_compatible(np, "operating-points-v2-kryo-cpu");
108 speedbin_nvmem = of_nvmem_cell_get(np, NULL);
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);
116 speedbin = nvmem_cell_read(speedbin_nvmem, &len);
117 nvmem_cell_put(speedbin_nvmem);
119 switch (msm8996_version) {
121 versions = 1 << (unsigned int)(*speedbin);
124 versions = 1 << ((unsigned int)(*speedbin) + 4);
131 for_each_possible_cpu(cpu) {
132 cpu_dev = get_cpu_device(cpu);
133 if (NULL == cpu_dev) {
138 opp_tables[cpu] = dev_pm_opp_set_supported_hw(cpu_dev,
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");
147 cpufreq_dt_pdev = platform_device_register_simple("cpufreq-dt", -1,
149 if (!IS_ERR(cpufreq_dt_pdev))
152 ret = PTR_ERR(cpufreq_dt_pdev);
153 dev_err(cpu_dev, "Failed to register platform device\n");
156 for_each_possible_cpu(cpu) {
157 if (IS_ERR_OR_NULL(opp_tables[cpu]))
159 dev_pm_opp_put_supported_hw(opp_tables[cpu]);
165 static struct platform_driver qcom_cpufreq_kryo_driver = {
166 .probe = qcom_cpufreq_kryo_probe,
168 .name = "qcom-cpufreq-kryo",
172 static const struct of_device_id qcom_cpufreq_kryo_match_list[] __initconst = {
173 { .compatible = "qcom,apq8096", },
174 { .compatible = "qcom,msm8996", },
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.
183 static int __init qcom_cpufreq_kryo_init(void)
185 struct device_node *np = of_find_node_by_path("/");
186 const struct of_device_id *match;
192 match = of_match_node(qcom_cpufreq_kryo_match_list, np);
197 ret = platform_driver_register(&qcom_cpufreq_kryo_driver);
198 if (unlikely(ret < 0))
201 ret = PTR_ERR_OR_ZERO(platform_device_register_simple(
202 "qcom-cpufreq-kryo", -1, NULL, 0));
206 platform_driver_unregister(&qcom_cpufreq_kryo_driver);
209 module_init(qcom_cpufreq_kryo_init);
211 MODULE_DESCRIPTION("Qualcomm Technologies, Inc. Kryo CPUfreq driver");
212 MODULE_LICENSE("GPL v2");