diff options
Diffstat (limited to 'drivers/base/power/opp/cpu.c')
| -rw-r--r-- | drivers/base/power/opp/cpu.c | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/drivers/base/power/opp/cpu.c b/drivers/base/power/opp/cpu.c new file mode 100644 index 000000000000..ba2bdbd932ef --- /dev/null +++ b/drivers/base/power/opp/cpu.c @@ -0,0 +1,271 @@ +/* + * Generic OPP helper interface for CPU device + * + * Copyright (C) 2009-2014 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/cpufreq.h> +#include <linux/err.h> +#include <linux/errno.h> +#include <linux/export.h> +#include <linux/of.h> +#include <linux/slab.h> + +#include "opp.h" + +#ifdef CONFIG_CPU_FREQ + +/** + * dev_pm_opp_init_cpufreq_table() - create a cpufreq table for a device + * @dev: device for which we do this operation + * @table: Cpufreq table returned back to caller + * + * Generate a cpufreq table for a provided device- this assumes that the + * opp table is already initialized and ready for usage. + * + * This function allocates required memory for the cpufreq table. It is + * expected that the caller does the required maintenance such as freeing + * the table as required. + * + * Returns -EINVAL for bad pointers, -ENODEV if the device is not found, -ENOMEM + * if no memory available for the operation (table is not populated), returns 0 + * if successful and table is populated. + * + * WARNING: It is important for the callers to ensure refreshing their copy of + * the table if any of the mentioned functions have been invoked in the interim. + * + * Locking: The internal opp_table and opp structures are RCU protected. + * Since we just use the regular accessor functions to access the internal data + * structures, we use RCU read lock inside this function. As a result, users of + * this function DONOT need to use explicit locks for invoking. + */ +int dev_pm_opp_init_cpufreq_table(struct device *dev, + struct cpufreq_frequency_table **table) +{ + struct dev_pm_opp *opp; + struct cpufreq_frequency_table *freq_table = NULL; + int i, max_opps, ret = 0; + unsigned long rate; + + rcu_read_lock(); + + max_opps = dev_pm_opp_get_opp_count(dev); + if (max_opps <= 0) { + ret = max_opps ? max_opps : -ENODATA; + goto out; + } + + freq_table = kcalloc((max_opps + 1), sizeof(*freq_table), GFP_ATOMIC); + if (!freq_table) { + ret = -ENOMEM; + goto out; + } + + for (i = 0, rate = 0; i < max_opps; i++, rate++) { + /* find next rate */ + opp = dev_pm_opp_find_freq_ceil(dev, &rate); + if (IS_ERR(opp)) { + ret = PTR_ERR(opp); + goto out; + } + freq_table[i].driver_data = i; + freq_table[i].frequency = rate / 1000; + + /* Is Boost/turbo opp ? */ + if (dev_pm_opp_is_turbo(opp)) + freq_table[i].flags = CPUFREQ_BOOST_FREQ; + } + + freq_table[i].driver_data = i; + freq_table[i].frequency = CPUFREQ_TABLE_END; + + *table = &freq_table[0]; + +out: + rcu_read_unlock(); + if (ret) + kfree(freq_table); + + return ret; +} +EXPORT_SYMBOL_GPL(dev_pm_opp_init_cpufreq_table); + +/** + * dev_pm_opp_free_cpufreq_table() - free the cpufreq table + * @dev: device for which we do this operation + * @table: table to free + * + * Free up the table allocated by dev_pm_opp_init_cpufreq_table + */ +void dev_pm_opp_free_cpufreq_table(struct device *dev, + struct cpufreq_frequency_table **table) +{ + if (!table) + return; + + kfree(*table); + *table = NULL; +} +EXPORT_SYMBOL_GPL(dev_pm_opp_free_cpufreq_table); +#endif /* CONFIG_CPU_FREQ */ + +/* Required only for V1 bindings, as v2 can manage it from DT itself */ +int dev_pm_opp_set_sharing_cpus(struct device *cpu_dev, cpumask_var_t cpumask) +{ + struct opp_device *opp_dev; + struct opp_table *opp_table; + struct device *dev; + int cpu, ret = 0; + + mutex_lock(&opp_table_lock); + + opp_table = _find_opp_table(cpu_dev); + if (IS_ERR(opp_table)) { + ret = -EINVAL; + goto unlock; + } + + for_each_cpu(cpu, cpumask) { + if (cpu == cpu_dev->id) + continue; + + dev = get_cpu_device(cpu); + if (!dev) { + dev_err(cpu_dev, "%s: failed to get cpu%d device\n", + __func__, cpu); + continue; + } + + opp_dev = _add_opp_dev(dev, opp_table); + if (!opp_dev) { + dev_err(dev, "%s: failed to add opp-dev for cpu%d device\n", + __func__, cpu); + continue; + } + } +unlock: + mutex_unlock(&opp_table_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(dev_pm_opp_set_sharing_cpus); + +#ifdef CONFIG_OF +void dev_pm_opp_of_cpumask_remove_table(cpumask_var_t cpumask) +{ + struct device *cpu_dev; + int cpu; + + 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; + } + + dev_pm_opp_of_remove_table(cpu_dev); + } +} +EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_remove_table); + +int dev_pm_opp_of_cpumask_add_table(cpumask_var_t 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. + */ +int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev, cpumask_var_t 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); +#endif |