@@ -216,6 +216,16 @@ config ARM_SPEAR_CPUFREQ
help
This adds the CPUFreq driver support for SPEAr SOCs.
+config ARM_STI_CPUFREQ
+ tristate "STi CPUFreq support"
+ depends on SOC_STIH407
+ help
+ This driver uses the generic OPP framework to match the running
+ platform with a predefined set of suitable values. If not provided
+ we will fall-back so safe-values contained in Device Tree. Enable
+ this config option if you wish to add CPUFreq support for STi based
+ SoCs.
+
config ARM_TEGRA20_CPUFREQ
bool "Tegra20 CPUFreq support"
depends on ARCH_TEGRA
@@ -73,6 +73,7 @@ obj-$(CONFIG_ARM_SA1100_CPUFREQ) += sa1100-cpufreq.o
obj-$(CONFIG_ARM_SA1110_CPUFREQ) += sa1110-cpufreq.o
obj-$(CONFIG_ARM_SCPI_CPUFREQ) += scpi-cpufreq.o
obj-$(CONFIG_ARM_SPEAR_CPUFREQ) += spear-cpufreq.o
+obj-$(CONFIG_ARM_STI_CPUFREQ) += sti-cpufreq.o
obj-$(CONFIG_ARM_TEGRA20_CPUFREQ) += tegra20-cpufreq.o
obj-$(CONFIG_ARM_TEGRA124_CPUFREQ) += tegra124-cpufreq.o
obj-$(CONFIG_ARM_VEXPRESS_SPC_CPUFREQ) += vexpress-spc-cpufreq.o
new file mode 100644
@@ -0,0 +1,294 @@
+/*
+ * Match running platform with pre-defined OPP values for CPUFreq
+ *
+ * Author: Ajit Pal Singh <ajitpal.singh@st.com>
+ * Lee Jones <lee.jones@linaro.org>
+ *
+ * Copyright (C) 2015 STMicroelectronics (R&D) Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the version 2 of the GNU General Public License as
+ * published by the Free Software Foundation
+ */
+
+#include <linux/cpu.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/pm_opp.h>
+#include <linux/regmap.h>
+
+#define VERSION_ELEMENTS 3
+#define MAX_PCODE_NAME_LEN 7
+
+#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,
+};
+
+/**
+ * ST CPUFreq Driver Data
+ *
+ * @cpu_node CPU's OF node
+ * @syscfg_eng Engineering Syscon register map
+ * @regmap 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 %s [%d]\n",
+ np->full_name, 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 %s [%d]\n",
+ np->full_name, 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"))
+ 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 ret;
+ char name[MAX_PCODE_NAME_LEN];
+
+ reg_fields = sti_cpufreq_match();
+ if (!reg_fields) {
+ dev_err(dev, "This SoC doesn't support voltage scaling");
+ 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);
+
+ ret = dev_pm_opp_set_prop_name(dev, name);
+ if (ret) {
+ dev_err(dev, "Failed to set prop name\n");
+ return ret;
+ }
+
+ version[0] = BIT(major);
+ version[1] = BIT(minor);
+ version[2] = BIT(substrate);
+
+ ret = dev_pm_opp_set_supported_hw(dev, version, VERSION_ELEMENTS);
+ if (ret) {
+ dev_err(dev, "Failed to set supported hardware\n");
+ return ret;
+ }
+
+ 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_regsiters(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 sti_cpufreq_init(void)
+{
+ int ret;
+
+ 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_get_property(ddata.cpu->of_node, "operating-points-v2", NULL)) {
+ dev_err(ddata.cpu, "OPP-v2 not supported\n");
+ goto skip_voltage_scaling;
+ }
+
+ ret = sti_cpufreq_fetch_syscon_regsiters();
+ 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);
+
+MODULE_DESCRIPTION("STMicroelectronics CPUFreq/OPP driver");
+MODULE_AUTHOR("Ajitpal Singh <ajitpal.singh@st.com>");
+MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org>");
+MODULE_LICENSE("GPL v2");