/*
* 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/slab.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.
*/
if (opp_table->shared_opp == OPP_TABLE_ACCESS_SHARED)
return opp_table;
return 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) {
/*
* In the case that no supported_hw has been set by the
* platform but there is an opp-supported-hw value set for
* an OPP then the OPP should not be enabled as there is
* no way to see if the hardware supports it.
*/
if (of_find_property(np, "opp-supported-hw", NULL))
return false;
else
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;
}
static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
struct opp_table *opp_table)
{
u32 *microvolt, *microamp = NULL;
int supplies, vcount, icount, ret, i, j;
struct property *prop = NULL;
char name[NAME_MAX];
supplies = opp_table->regulator_count ? opp_table->regulator_count : 1;
/* 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;
}
vcount = of_property_count_u32_elems(opp->np, name);
if (vcount < 0) {
dev_err(dev, "%s: Invalid %s property (%d)\n",
__func__, name, vcount);
return vcount;
}
/* There can be one or three elements per supply */
if (vcount != supplies && vcount != supplies * 3) {
dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
__func__, name, vcount, supplies);
return -EINVAL;
}
microvolt = kmalloc_array(vcount, sizeof(*microvolt), GFP_KERNEL);
if (!microvolt)
return -ENOMEM;
ret = of_property_read_u32_array(opp->np, name, microvolt, vcount);
if (ret) {
dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret);
ret = -EINVAL;
goto free_microvolt;
}
/* 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) {
icount = of_property_count_u32_elems(opp->np, name);
if (icount < 0) {
dev_err(dev, "%s: Invalid %s property (%d)\n", __func__,
name, icount);
ret = icount;
goto free_microvolt;
}
if (icount != supplies) {
dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
__func__, name, icount, supplies);
ret = -EINVAL;
goto free_microvolt;
}
microamp = kmalloc_array(icount, sizeof(*microamp), GFP_KERNEL);
if (!microamp) {
ret = -EINVAL;
goto free_microvolt;
}
ret = of_property_read_u32_array(opp->np, name, microamp,
icount);
if (ret) {
dev_err(dev, "%s: error parsing %s: %d\n", __func__,
name, ret);
ret = -EINVAL;
goto free_microamp;
}
}
for (i = 0, j = 0; i < supplies; i++) {
opp->supplies[i].u_volt = microvolt[j++];
if (vcount == supplies) {
opp->supplies[i].u_volt_min = opp->supplies[i].u_volt;
opp->supplies[i].u_volt_max = opp->supplies[i].u_volt;
} else {
opp->supplies[i].u_volt_min = microvolt[j++];
opp->supplies[i].u_volt_max = microvolt[j++];
}
if (microamp)
opp->supplies[i].u_amp = microamp[i];
}
free_microamp:
kfree(microamp);
free_microvolt:
kfree(microvolt);
return ret;
}
/**
* 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() */
static 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->supplies[0].u_volt, new_opp->supplies[0].u_volt_min,
new_opp->supplies[0].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;
if (of_property_read_bool(opp_np, "opp-shared"))
opp_table->shared_opp = OPP_TABLE_ACCESS_SHARED;
else
opp_table->shared_opp = OPP_TABLE_ACCESS_EXCLUSIVE;
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 opp 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 opp 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);
