// SPDX-License-Identifier: GPL-2.0-only /* * Match running platform with pre-defined OPP values for CPUFreq * * Author: Ajit Pal Singh * Lee Jones * * Copyright (C) 2015 STMicroelectronics (R&D) Limited */ #include #include #include #include #include #include #include #include #define VERSION_ELEMENTS 3 #define MAX_PCODE_NAME_LEN 16 #define VERSION_SHIFT 28 #define HW_INFO_INDEX 1 #define MAJOR_ID_INDEX 1 #define MINOR_ID_INDEX 2 /* * Only match on "suitable for ALL versions" entries * * This will be used with the BIT() macro. It sets the * top bit of a 32bit value and is equal to 0x80000000. */ #define DEFAULT_VERSION 31 enum { PCODE = 0, SUBSTRATE, DVFS_MAX_REGFIELDS, }; /** * struct sti_cpufreq_ddata - ST CPUFreq Driver Data * * @cpu: CPU's OF node * @syscfg_eng: Engineering Syscon register map * @syscfg: Syscon register map */ static struct sti_cpufreq_ddata { struct device *cpu; struct regmap *syscfg_eng; struct regmap *syscfg; } ddata; static int sti_cpufreq_fetch_major(void) { struct device_node *np = ddata.cpu->of_node; struct device *dev = ddata.cpu; unsigned int major_offset; unsigned int socid; int ret; ret = of_property_read_u32_index(np, "st,syscfg", MAJOR_ID_INDEX, &major_offset); if (ret) { dev_err(dev, "No major number offset provided in %pOF [%d]\n", np, ret); return ret; } ret = regmap_read(ddata.syscfg, major_offset, &socid); if (ret) { dev_err(dev, "Failed to read major number from syscon [%d]\n", ret); return ret; } return ((socid >> VERSION_SHIFT) & 0xf) + 1; } static int sti_cpufreq_fetch_minor(void) { struct device *dev = ddata.cpu; struct device_node *np = dev->of_node; unsigned int minor_offset; unsigned int minid; int ret; ret = of_property_read_u32_index(np, "st,syscfg-eng", MINOR_ID_INDEX, &minor_offset); if (ret) { dev_err(dev, "No minor number offset provided %pOF [%d]\n", np, ret); return ret; } ret = regmap_read(ddata.syscfg_eng, minor_offset, &minid); if (ret) { dev_err(dev, "Failed to read the minor number from syscon [%d]\n", ret); return ret; } return minid & 0xf; } static int sti_cpufreq_fetch_regmap_field(const struct reg_field *reg_fields, int hw_info_offset, int field) { struct regmap_field *regmap_field; struct reg_field reg_field = reg_fields[field]; struct device *dev = ddata.cpu; unsigned int value; int ret; reg_field.reg = hw_info_offset; regmap_field = devm_regmap_field_alloc(dev, ddata.syscfg_eng, reg_field); if (IS_ERR(regmap_field)) { dev_err(dev, "Failed to allocate reg field\n"); return PTR_ERR(regmap_field); } ret = regmap_field_read(regmap_field, &value); if (ret) { dev_err(dev, "Failed to read %s code\n", field ? "SUBSTRATE" : "PCODE"); return ret; } return value; } static const struct reg_field sti_stih407_dvfs_regfields[DVFS_MAX_REGFIELDS] = { [PCODE] = REG_FIELD(0, 16, 19), [SUBSTRATE] = REG_FIELD(0, 0, 2), }; static const struct reg_field *sti_cpufreq_match(void) { if (of_machine_is_compatible("st,stih407") || of_machine_is_compatible("st,stih410") || of_machine_is_compatible("st,stih418")) return sti_stih407_dvfs_regfields; return NULL; } static int sti_cpufreq_set_opp_info(void) { struct device *dev = ddata.cpu; struct device_node *np = dev->of_node; const struct reg_field *reg_fields; unsigned int hw_info_offset; unsigned int version[VERSION_ELEMENTS]; int pcode, substrate, major, minor; int opp_token, ret; char name[MAX_PCODE_NAME_LEN]; struct dev_pm_opp_config config = { .supported_hw = version, .supported_hw_count = ARRAY_SIZE(version), .prop_name = name, }; reg_fields = sti_cpufreq_match(); if (!reg_fields) { dev_err(dev, "This SoC doesn't support voltage scaling\n"); return -ENODEV; } ret = of_property_read_u32_index(np, "st,syscfg-eng", HW_INFO_INDEX, &hw_info_offset); if (ret) { dev_warn(dev, "Failed to read HW info offset from DT\n"); substrate = DEFAULT_VERSION; pcode = 0; goto use_defaults; } pcode = sti_cpufreq_fetch_regmap_field(reg_fields, hw_info_offset, PCODE); if (pcode < 0) { dev_warn(dev, "Failed to obtain process code\n"); /* Use default pcode */ pcode = 0; } substrate = sti_cpufreq_fetch_regmap_field(reg_fields, hw_info_offset, SUBSTRATE); if (substrate) { dev_warn(dev, "Failed to obtain substrate code\n"); /* Use default substrate */ substrate = DEFAULT_VERSION; } use_defaults: major = sti_cpufreq_fetch_major(); if (major < 0) { dev_err(dev, "Failed to obtain major version\n"); /* Use default major number */ major = DEFAULT_VERSION; } minor = sti_cpufreq_fetch_minor(); if (minor < 0) { dev_err(dev, "Failed to obtain minor version\n"); /* Use default minor number */ minor = DEFAULT_VERSION; } snprintf(name, MAX_PCODE_NAME_LEN, "pcode%d", pcode); version[0] = BIT(major); version[1] = BIT(minor); version[2] = BIT(substrate); opp_token = dev_pm_opp_set_config(dev, &config); if (opp_token < 0) { dev_err(dev, "Failed to set OPP config\n"); return opp_token; } dev_dbg(dev, "pcode: %d major: %d minor: %d substrate: %d\n", pcode, major, minor, substrate); dev_dbg(dev, "version[0]: %x version[1]: %x version[2]: %x\n", version[0], version[1], version[2]); return 0; } static int sti_cpufreq_fetch_syscon_registers(void) { struct device *dev = ddata.cpu; struct device_node *np = dev->of_node; ddata.syscfg = syscon_regmap_lookup_by_phandle(np, "st,syscfg"); if (IS_ERR(ddata.syscfg)) { dev_err(dev, "\"st,syscfg\" not supplied\n"); return PTR_ERR(ddata.syscfg); } ddata.syscfg_eng = syscon_regmap_lookup_by_phandle(np, "st,syscfg-eng"); if (IS_ERR(ddata.syscfg_eng)) { dev_err(dev, "\"st,syscfg-eng\" not supplied\n"); return PTR_ERR(ddata.syscfg_eng); } return 0; } static int __init sti_cpufreq_init(void) { int ret; if ((!of_machine_is_compatible("st,stih407")) && (!of_machine_is_compatible("st,stih410")) && (!of_machine_is_compatible("st,stih418"))) return -ENODEV; ddata.cpu = get_cpu_device(0); if (!ddata.cpu) { dev_err(ddata.cpu, "Failed to get device for CPU0\n"); goto skip_voltage_scaling; } if (!of_property_present(ddata.cpu->of_node, "operating-points-v2")) { dev_err(ddata.cpu, "OPP-v2 not supported\n"); goto skip_voltage_scaling; } ret = sti_cpufreq_fetch_syscon_registers(); if (ret) goto skip_voltage_scaling; ret = sti_cpufreq_set_opp_info(); if (!ret) goto register_cpufreq_dt; skip_voltage_scaling: dev_err(ddata.cpu, "Not doing voltage scaling\n"); register_cpufreq_dt: platform_device_register_simple("cpufreq-dt", -1, NULL, 0); return 0; } module_init(sti_cpufreq_init); static const struct of_device_id __maybe_unused sti_cpufreq_of_match[] = { { .compatible = "st,stih407" }, { .compatible = "st,stih410" }, { .compatible = "st,stih418" }, { }, }; MODULE_DEVICE_TABLE(of, sti_cpufreq_of_match); MODULE_DESCRIPTION("STMicroelectronics CPUFreq/OPP driver"); MODULE_AUTHOR("Ajitpal Singh "); MODULE_AUTHOR("Lee Jones "); MODULE_LICENSE("GPL v2");