qcom-cpufreq-kryo.c
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2018, The Linux Foundation. All rights reserved.
*/
/*
* In Certain QCOM SoCs like apq8096 and msm8996 that have KRYO processors,
* the CPU frequency subset and voltage value of each OPP varies
* based on the silicon variant in use. Qualcomm Process Voltage Scaling Tables
* defines the voltage and frequency value based on the msm-id in SMEM
* and speedbin blown in the efuse combination.
* The qcom-cpufreq-kryo driver reads the msm-id and efuse value from the SoC
* to provide the OPP framework with required information.
* This is used to determine the voltage and frequency value for each OPP of
* operating-points-v2 table when it is parsed by the OPP framework.
*/
#include <linux/cpu.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/nvmem-consumer.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_opp.h>
#include <linux/slab.h>
#include <linux/soc/qcom/smem.h>
#define MSM_ID_SMEM 137
enum _msm_id {
MSM8996V3 = 0xF6ul,
APQ8096V3 = 0x123ul,
MSM8996SG = 0x131ul,
APQ8096SG = 0x138ul,
};
enum _msm8996_version {
MSM8996_V3,
MSM8996_SG,
NUM_OF_MSM8996_VERSIONS,
};
static struct platform_device *cpufreq_dt_pdev, *kryo_cpufreq_pdev;
static enum _msm8996_version qcom_cpufreq_kryo_get_msm_id(void)
{
size_t len;
u32 *msm_id;
enum _msm8996_version version;
msm_id = qcom_smem_get(QCOM_SMEM_HOST_ANY, MSM_ID_SMEM, &len);
if (IS_ERR(msm_id))
return NUM_OF_MSM8996_VERSIONS;
/* The first 4 bytes are format, next to them is the actual msm-id */
msm_id++;
switch ((enum _msm_id)*msm_id) {
case MSM8996V3:
case APQ8096V3:
version = MSM8996_V3;
break;
case MSM8996SG:
case APQ8096SG:
version = MSM8996_SG;
break;
default:
version = NUM_OF_MSM8996_VERSIONS;
}
return version;
}
static int qcom_cpufreq_kryo_probe(struct platform_device *pdev)
{
struct opp_table **opp_tables;
enum _msm8996_version msm8996_version;
struct nvmem_cell *speedbin_nvmem;
struct device_node *np;
struct device *cpu_dev;
unsigned cpu;
u8 *speedbin;
u32 versions;
size_t len;
int ret;
cpu_dev = get_cpu_device(0);
if (!cpu_dev)
return -ENODEV;
msm8996_version = qcom_cpufreq_kryo_get_msm_id();
if (NUM_OF_MSM8996_VERSIONS == msm8996_version) {
dev_err(cpu_dev, "Not Snapdragon 820/821!");
return -ENODEV;
}
np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
if (!np)
return -ENOENT;
ret = of_device_is_compatible(np, "operating-points-v2-kryo-cpu");
if (!ret) {
of_node_put(np);
return -ENOENT;
}
speedbin_nvmem = of_nvmem_cell_get(np, NULL);
of_node_put(np);
if (IS_ERR(speedbin_nvmem)) {
if (PTR_ERR(speedbin_nvmem) != -EPROBE_DEFER)
dev_err(cpu_dev, "Could not get nvmem cell: %ld\n",
PTR_ERR(speedbin_nvmem));
return PTR_ERR(speedbin_nvmem);
}
speedbin = nvmem_cell_read(speedbin_nvmem, &len);
nvmem_cell_put(speedbin_nvmem);
if (IS_ERR(speedbin))
return PTR_ERR(speedbin);
switch (msm8996_version) {
case MSM8996_V3:
versions = 1 << (unsigned int)(*speedbin);
break;
case MSM8996_SG:
versions = 1 << ((unsigned int)(*speedbin) + 4);
break;
default:
BUG();
break;
}
kfree(speedbin);
opp_tables = kcalloc(num_possible_cpus(), sizeof(*opp_tables), GFP_KERNEL);
if (!opp_tables)
return -ENOMEM;
for_each_possible_cpu(cpu) {
cpu_dev = get_cpu_device(cpu);
if (NULL == cpu_dev) {
ret = -ENODEV;
goto free_opp;
}
opp_tables[cpu] = dev_pm_opp_set_supported_hw(cpu_dev,
&versions, 1);
if (IS_ERR(opp_tables[cpu])) {
ret = PTR_ERR(opp_tables[cpu]);
dev_err(cpu_dev, "Failed to set supported hardware\n");
goto free_opp;
}
}
cpufreq_dt_pdev = platform_device_register_simple("cpufreq-dt", -1,
NULL, 0);
if (!IS_ERR(cpufreq_dt_pdev)) {
platform_set_drvdata(pdev, opp_tables);
return 0;
}
ret = PTR_ERR(cpufreq_dt_pdev);
dev_err(cpu_dev, "Failed to register platform device\n");
free_opp:
for_each_possible_cpu(cpu) {
if (IS_ERR_OR_NULL(opp_tables[cpu]))
break;
dev_pm_opp_put_supported_hw(opp_tables[cpu]);
}
kfree(opp_tables);
return ret;
}
static int qcom_cpufreq_kryo_remove(struct platform_device *pdev)
{
struct opp_table **opp_tables = platform_get_drvdata(pdev);
unsigned int cpu;
platform_device_unregister(cpufreq_dt_pdev);
for_each_possible_cpu(cpu)
dev_pm_opp_put_supported_hw(opp_tables[cpu]);
kfree(opp_tables);
return 0;
}
static struct platform_driver qcom_cpufreq_kryo_driver = {
.probe = qcom_cpufreq_kryo_probe,
.remove = qcom_cpufreq_kryo_remove,
.driver = {
.name = "qcom-cpufreq-kryo",
},
};
static const struct of_device_id qcom_cpufreq_kryo_match_list[] __initconst = {
{ .compatible = "qcom,apq8096", },
{ .compatible = "qcom,msm8996", },
{}
};
/*
* Since the driver depends on smem and nvmem drivers, which may
* return EPROBE_DEFER, all the real activity is done in the probe,
* which may be defered as well. The init here is only registering
* the driver and the platform device.
*/
static int __init qcom_cpufreq_kryo_init(void)
{
struct device_node *np = of_find_node_by_path("/");
const struct of_device_id *match;
int ret;
if (!np)
return -ENODEV;
match = of_match_node(qcom_cpufreq_kryo_match_list, np);
of_node_put(np);
if (!match)
return -ENODEV;
ret = platform_driver_register(&qcom_cpufreq_kryo_driver);
if (unlikely(ret < 0))
return ret;
kryo_cpufreq_pdev = platform_device_register_simple(
"qcom-cpufreq-kryo", -1, NULL, 0);
ret = PTR_ERR_OR_ZERO(kryo_cpufreq_pdev);
if (0 == ret)
return 0;
platform_driver_unregister(&qcom_cpufreq_kryo_driver);
return ret;
}
module_init(qcom_cpufreq_kryo_init);
static void __exit qcom_cpufreq_kryo_exit(void)
{
platform_device_unregister(kryo_cpufreq_pdev);
platform_driver_unregister(&qcom_cpufreq_kryo_driver);
}
module_exit(qcom_cpufreq_kryo_exit);
MODULE_DESCRIPTION("Qualcomm Technologies, Inc. Kryo CPUfreq driver");
MODULE_LICENSE("GPL v2");