diff options
Diffstat (limited to 'drivers/base/power/opp/of.c')
| -rw-r--r-- | drivers/base/power/opp/of.c | 591 |
1 files changed, 591 insertions, 0 deletions
diff --git a/drivers/base/power/opp/of.c b/drivers/base/power/opp/of.c new file mode 100644 index 000000000000..94d2010558e3 --- /dev/null +++ b/drivers/base/power/opp/of.c @@ -0,0 +1,591 @@ +/* + * Generic OPP OF helpers + * + * Copyright (C) 2009-2010 Texas Instruments Incorporated. + * Nishanth Menon + * Romit Dasgupta + * Kevin Hilman + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/cpu.h> +#include <linux/errno.h> +#include <linux/device.h> +#include <linux/of.h> +#include <linux/export.h> + +#include "opp.h" + +static struct opp_table *_managed_opp(const struct device_node *np) +{ + struct opp_table *opp_table; + + list_for_each_entry_rcu(opp_table, &opp_tables, node) { + if (opp_table->np == np) { + /* + * Multiple devices can point to the same OPP table and + * so will have same node-pointer, np. + * + * But the OPPs will be considered as shared only if the + * OPP table contains a "opp-shared" property. + */ + return opp_table->shared_opp ? opp_table : NULL; + } + } + + return NULL; +} + +void _of_init_opp_table(struct opp_table *opp_table, struct device *dev) +{ + struct device_node *np; + + /* + * Only required for backward compatibility with v1 bindings, but isn't + * harmful for other cases. And so we do it unconditionally. + */ + np = of_node_get(dev->of_node); + if (np) { + u32 val; + + if (!of_property_read_u32(np, "clock-latency", &val)) + opp_table->clock_latency_ns_max = val; + of_property_read_u32(np, "voltage-tolerance", + &opp_table->voltage_tolerance_v1); + of_node_put(np); + } +} + +static bool _opp_is_supported(struct device *dev, struct opp_table *opp_table, + struct device_node *np) +{ + unsigned int count = opp_table->supported_hw_count; + u32 version; + int ret; + + if (!opp_table->supported_hw) + return true; + + while (count--) { + ret = of_property_read_u32_index(np, "opp-supported-hw", count, + &version); + if (ret) { + dev_warn(dev, "%s: failed to read opp-supported-hw property at index %d: %d\n", + __func__, count, ret); + return false; + } + + /* Both of these are bitwise masks of the versions */ + if (!(version & opp_table->supported_hw[count])) + return false; + } + + return true; +} + +/* TODO: Support multiple regulators */ +static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev, + struct opp_table *opp_table) +{ + u32 microvolt[3] = {0}; + u32 val; + int count, ret; + struct property *prop = NULL; + char name[NAME_MAX]; + + /* Search for "opp-microvolt-<name>" */ + if (opp_table->prop_name) { + snprintf(name, sizeof(name), "opp-microvolt-%s", + opp_table->prop_name); + prop = of_find_property(opp->np, name, NULL); + } + + if (!prop) { + /* Search for "opp-microvolt" */ + sprintf(name, "opp-microvolt"); + prop = of_find_property(opp->np, name, NULL); + + /* Missing property isn't a problem, but an invalid entry is */ + if (!prop) + return 0; + } + + count = of_property_count_u32_elems(opp->np, name); + if (count < 0) { + dev_err(dev, "%s: Invalid %s property (%d)\n", + __func__, name, count); + return count; + } + + /* There can be one or three elements here */ + if (count != 1 && count != 3) { + dev_err(dev, "%s: Invalid number of elements in %s property (%d)\n", + __func__, name, count); + return -EINVAL; + } + + ret = of_property_read_u32_array(opp->np, name, microvolt, count); + if (ret) { + dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret); + return -EINVAL; + } + + opp->u_volt = microvolt[0]; + + if (count == 1) { + opp->u_volt_min = opp->u_volt; + opp->u_volt_max = opp->u_volt; + } else { + opp->u_volt_min = microvolt[1]; + opp->u_volt_max = microvolt[2]; + } + + /* Search for "opp-microamp-<name>" */ + prop = NULL; + if (opp_table->prop_name) { + snprintf(name, sizeof(name), "opp-microamp-%s", + opp_table->prop_name); + prop = of_find_property(opp->np, name, NULL); + } + + if (!prop) { + /* Search for "opp-microamp" */ + sprintf(name, "opp-microamp"); + prop = of_find_property(opp->np, name, NULL); + } + + if (prop && !of_property_read_u32(opp->np, name, &val)) + opp->u_amp = val; + + return 0; +} + +/** + * dev_pm_opp_of_remove_table() - Free OPP table entries created from static DT + * entries + * @dev: device pointer used to lookup OPP table. + * + * Free OPPs created using static entries present in DT. + * + * Locking: The internal opp_table and opp structures are RCU protected. + * Hence this function indirectly uses RCU updater strategy with mutex locks + * to keep the integrity of the internal data structures. Callers should ensure + * that this function is *NOT* called under RCU protection or in contexts where + * mutex cannot be locked. + */ +void dev_pm_opp_of_remove_table(struct device *dev) +{ + _dev_pm_opp_remove_table(dev, false); +} +EXPORT_SYMBOL_GPL(dev_pm_opp_of_remove_table); + +/* Returns opp descriptor node for a device, caller must do of_node_put() */ +struct device_node *_of_get_opp_desc_node(struct device *dev) +{ + /* + * TODO: Support for multiple OPP tables. + * + * There should be only ONE phandle present in "operating-points-v2" + * property. + */ + + return of_parse_phandle(dev->of_node, "operating-points-v2", 0); +} + +/** + * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings) + * @dev: device for which we do this operation + * @np: device node + * + * This function adds an opp definition to the opp table and returns status. The + * opp can be controlled using dev_pm_opp_enable/disable functions and may be + * removed by dev_pm_opp_remove. + * + * Locking: The internal opp_table and opp structures are RCU protected. + * Hence this function internally uses RCU updater strategy with mutex locks + * to keep the integrity of the internal data structures. Callers should ensure + * that this function is *NOT* called under RCU protection or in contexts where + * mutex cannot be locked. + * + * Return: + * 0 On success OR + * Duplicate OPPs (both freq and volt are same) and opp->available + * -EEXIST Freq are same and volt are different OR + * Duplicate OPPs (both freq and volt are same) and !opp->available + * -ENOMEM Memory allocation failure + * -EINVAL Failed parsing the OPP node + */ +static int _opp_add_static_v2(struct device *dev, struct device_node *np) +{ + struct opp_table *opp_table; + struct dev_pm_opp *new_opp; + u64 rate; + u32 val; + int ret; + + /* Hold our table modification lock here */ + mutex_lock(&opp_table_lock); + + new_opp = _allocate_opp(dev, &opp_table); + if (!new_opp) { + ret = -ENOMEM; + goto unlock; + } + + ret = of_property_read_u64(np, "opp-hz", &rate); + if (ret < 0) { + dev_err(dev, "%s: opp-hz not found\n", __func__); + goto free_opp; + } + + /* Check if the OPP supports hardware's hierarchy of versions or not */ + if (!_opp_is_supported(dev, opp_table, np)) { + dev_dbg(dev, "OPP not supported by hardware: %llu\n", rate); + goto free_opp; + } + + /* + * Rate is defined as an unsigned long in clk API, and so casting + * explicitly to its type. Must be fixed once rate is 64 bit + * guaranteed in clk API. + */ + new_opp->rate = (unsigned long)rate; + new_opp->turbo = of_property_read_bool(np, "turbo-mode"); + + new_opp->np = np; + new_opp->dynamic = false; + new_opp->available = true; + + if (!of_property_read_u32(np, "clock-latency-ns", &val)) + new_opp->clock_latency_ns = val; + + ret = opp_parse_supplies(new_opp, dev, opp_table); + if (ret) + goto free_opp; + + ret = _opp_add(dev, new_opp, opp_table); + if (ret) + goto free_opp; + + /* OPP to select on device suspend */ + if (of_property_read_bool(np, "opp-suspend")) { + if (opp_table->suspend_opp) { + dev_warn(dev, "%s: Multiple suspend OPPs found (%lu %lu)\n", + __func__, opp_table->suspend_opp->rate, + new_opp->rate); + } else { + new_opp->suspend = true; + opp_table->suspend_opp = new_opp; + } + } + + if (new_opp->clock_latency_ns > opp_table->clock_latency_ns_max) + opp_table->clock_latency_ns_max = new_opp->clock_latency_ns; + + mutex_unlock(&opp_table_lock); + + pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu latency:%lu\n", + __func__, new_opp->turbo, new_opp->rate, new_opp->u_volt, + new_opp->u_volt_min, new_opp->u_volt_max, + new_opp->clock_latency_ns); + + /* + * Notify the changes in the availability of the operable + * frequency/voltage list. + */ + srcu_notifier_call_chain(&opp_table->srcu_head, OPP_EVENT_ADD, new_opp); + return 0; + +free_opp: + _opp_remove(opp_table, new_opp, false); +unlock: + mutex_unlock(&opp_table_lock); + return ret; +} + +/* Initializes OPP tables based on new bindings */ +static int _of_add_opp_table_v2(struct device *dev, struct device_node *opp_np) +{ + struct device_node *np; + struct opp_table *opp_table; + int ret = 0, count = 0; + + mutex_lock(&opp_table_lock); + + opp_table = _managed_opp(opp_np); + if (opp_table) { + /* OPPs are already managed */ + if (!_add_opp_dev(dev, opp_table)) + ret = -ENOMEM; + mutex_unlock(&opp_table_lock); + return ret; + } + mutex_unlock(&opp_table_lock); + + /* We have opp-table node now, iterate over it and add OPPs */ + for_each_available_child_of_node(opp_np, np) { + count++; + + ret = _opp_add_static_v2(dev, np); + if (ret) { + dev_err(dev, "%s: Failed to add OPP, %d\n", __func__, + ret); + goto free_table; + } + } + + /* There should be one of more OPP defined */ + if (WARN_ON(!count)) + return -ENOENT; + + mutex_lock(&opp_table_lock); + + opp_table = _find_opp_table(dev); + if (WARN_ON(IS_ERR(opp_table))) { + ret = PTR_ERR(opp_table); + mutex_unlock(&opp_table_lock); + goto free_table; + } + + opp_table->np = opp_np; + opp_table->shared_opp = of_property_read_bool(opp_np, "opp-shared"); + + mutex_unlock(&opp_table_lock); + + return 0; + +free_table: + dev_pm_opp_of_remove_table(dev); + + return ret; +} + +/* Initializes OPP tables based on old-deprecated bindings */ +static int _of_add_opp_table_v1(struct device *dev) +{ + const struct property *prop; + const __be32 *val; + int nr; + + prop = of_find_property(dev->of_node, "operating-points", NULL); + if (!prop) + return -ENODEV; + if (!prop->value) + return -ENODATA; + + /* + * Each OPP is a set of tuples consisting of frequency and + * voltage like <freq-kHz vol-uV>. + */ + nr = prop->length / sizeof(u32); + if (nr % 2) { + dev_err(dev, "%s: Invalid OPP table\n", __func__); + return -EINVAL; + } + + val = prop->value; + while (nr) { + unsigned long freq = be32_to_cpup(val++) * 1000; + unsigned long volt = be32_to_cpup(val++); + + if (_opp_add_v1(dev, freq, volt, false)) + dev_warn(dev, "%s: Failed to add OPP %ld\n", + __func__, freq); + nr -= 2; + } + + return 0; +} + +/** + * dev_pm_opp_of_add_table() - Initialize opp table from device tree + * @dev: device pointer used to lookup OPP table. + * + * Register the initial OPP table with the OPP library for given device. + * + * Locking: The internal opp_table and opp structures are RCU protected. + * Hence this function indirectly uses RCU updater strategy with mutex locks + * to keep the integrity of the internal data structures. Callers should ensure + * that this function is *NOT* called under RCU protection or in contexts where + * mutex cannot be locked. + * + * Return: + * 0 On success OR + * Duplicate OPPs (both freq and volt are same) and opp->available + * -EEXIST Freq are same and volt are different OR + * Duplicate OPPs (both freq and volt are same) and !opp->available + * -ENOMEM Memory allocation failure + * -ENODEV when 'operating-points' property is not found or is invalid data + * in device node. + * -ENODATA when empty 'operating-points' property is found + * -EINVAL when invalid entries are found in opp-v2 table + */ +int dev_pm_opp_of_add_table(struct device *dev) +{ + struct device_node *opp_np; + int ret; + + /* + * OPPs have two version of bindings now. The older one is deprecated, + * try for the new binding first. + */ + opp_np = _of_get_opp_desc_node(dev); + if (!opp_np) { + /* + * Try old-deprecated bindings for backward compatibility with + * older dtbs. + */ + return _of_add_opp_table_v1(dev); + } + + ret = _of_add_opp_table_v2(dev, opp_np); + of_node_put(opp_np); + + return ret; +} +EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table); + +/* CPU device specific helpers */ + +/** + * dev_pm_opp_of_cpumask_remove_table() - Removes OPP table for @cpumask + * @cpumask: cpumask for which OPP table needs to be removed + * + * This removes the OPP tables for CPUs present in the @cpumask. + * This should be used only to remove static entries created from DT. + * + * Locking: The internal opp_table and opp structures are RCU protected. + * Hence this function internally uses RCU updater strategy with mutex locks + * to keep the integrity of the internal data structures. Callers should ensure + * that this function is *NOT* called under RCU protection or in contexts where + * mutex cannot be locked. + */ +void dev_pm_opp_of_cpumask_remove_table(const struct cpumask *cpumask) +{ + _dev_pm_opp_cpumask_remove_table(cpumask, true); +} +EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_remove_table); + +/** + * dev_pm_opp_of_cpumask_add_table() - Adds OPP table for @cpumask + * @cpumask: cpumask for which OPP table needs to be added. + * + * This adds the OPP tables for CPUs present in the @cpumask. + * + * Locking: The internal opp_table and opp structures are RCU protected. + * Hence this function internally uses RCU updater strategy with mutex locks + * to keep the integrity of the internal data structures. Callers should ensure + * that this function is *NOT* called under RCU protection or in contexts where + * mutex cannot be locked. + */ +int dev_pm_opp_of_cpumask_add_table(const struct cpumask *cpumask) +{ + struct device *cpu_dev; + int cpu, ret = 0; + + WARN_ON(cpumask_empty(cpumask)); + + for_each_cpu(cpu, cpumask) { + cpu_dev = get_cpu_device(cpu); + if (!cpu_dev) { + pr_err("%s: failed to get cpu%d device\n", __func__, + cpu); + continue; + } + + ret = dev_pm_opp_of_add_table(cpu_dev); + if (ret) { + pr_err("%s: couldn't find opp table for cpu:%d, %d\n", + __func__, cpu, ret); + + /* Free all other OPPs */ + dev_pm_opp_of_cpumask_remove_table(cpumask); + break; + } + } + + return ret; +} +EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_add_table); + +/* + * Works only for OPP v2 bindings. + * + * Returns -ENOENT if operating-points-v2 bindings aren't supported. + */ +/** + * dev_pm_opp_of_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with + * @cpu_dev using operating-points-v2 + * bindings. + * + * @cpu_dev: CPU device for which we do this operation + * @cpumask: cpumask to update with information of sharing CPUs + * + * This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev. + * + * Returns -ENOENT if operating-points-v2 isn't present for @cpu_dev. + * + * Locking: The internal opp_table and opp structures are RCU protected. + * Hence this function internally uses RCU updater strategy with mutex locks + * to keep the integrity of the internal data structures. Callers should ensure + * that this function is *NOT* called under RCU protection or in contexts where + * mutex cannot be locked. + */ +int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev, + struct cpumask *cpumask) +{ + struct device_node *np, *tmp_np; + struct device *tcpu_dev; + int cpu, ret = 0; + + /* Get OPP descriptor node */ + np = _of_get_opp_desc_node(cpu_dev); + if (!np) { + dev_dbg(cpu_dev, "%s: Couldn't find cpu_dev node.\n", __func__); + return -ENOENT; + } + + cpumask_set_cpu(cpu_dev->id, cpumask); + + /* OPPs are shared ? */ + if (!of_property_read_bool(np, "opp-shared")) + goto put_cpu_node; + + for_each_possible_cpu(cpu) { + if (cpu == cpu_dev->id) + continue; + + tcpu_dev = get_cpu_device(cpu); + if (!tcpu_dev) { + dev_err(cpu_dev, "%s: failed to get cpu%d device\n", + __func__, cpu); + ret = -ENODEV; + goto put_cpu_node; + } + + /* Get OPP descriptor node */ + tmp_np = _of_get_opp_desc_node(tcpu_dev); + if (!tmp_np) { + dev_err(tcpu_dev, "%s: Couldn't find tcpu_dev node.\n", + __func__); + ret = -ENOENT; + goto put_cpu_node; + } + + /* CPUs are sharing opp node */ + if (np == tmp_np) + cpumask_set_cpu(cpu, cpumask); + + of_node_put(tmp_np); + } + +put_cpu_node: + of_node_put(np); + return ret; +} +EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_sharing_cpus); |