summaryrefslogtreecommitdiff
path: root/drivers/cpufreq/cpufreq_opp.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2014-06-08 11:31:16 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-06-08 11:31:16 -0700
commit3f17ea6dea8ba5668873afa54628a91aaa3fb1c0 (patch)
treeafbeb2accd4c2199ddd705ae943995b143a0af02 /drivers/cpufreq/cpufreq_opp.c
parent1860e379875dfe7271c649058aeddffe5afd9d0d (diff)
parent1a5700bc2d10cd379a795fd2bb377a190af5acd4 (diff)
Merge branch 'next' (accumulated 3.16 merge window patches) into master
Now that 3.15 is released, this merges the 'next' branch into 'master', bringing us to the normal situation where my 'master' branch is the merge window. * accumulated work in next: (6809 commits) ufs: sb mutex merge + mutex_destroy powerpc: update comments for generic idle conversion cris: update comments for generic idle conversion idle: remove cpu_idle() forward declarations nbd: zero from and len fields in NBD_CMD_DISCONNECT. mm: convert some level-less printks to pr_* MAINTAINERS: adi-buildroot-devel is moderated MAINTAINERS: add linux-api for review of API/ABI changes mm/kmemleak-test.c: use pr_fmt for logging fs/dlm/debug_fs.c: replace seq_printf by seq_puts fs/dlm/lockspace.c: convert simple_str to kstr fs/dlm/config.c: convert simple_str to kstr mm: mark remap_file_pages() syscall as deprecated mm: memcontrol: remove unnecessary memcg argument from soft limit functions mm: memcontrol: clean up memcg zoneinfo lookup mm/memblock.c: call kmemleak directly from memblock_(alloc|free) mm/mempool.c: update the kmemleak stack trace for mempool allocations lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations mm: introduce kmemleak_update_trace() mm/kmemleak.c: use %u to print ->checksum ...
Diffstat (limited to 'drivers/cpufreq/cpufreq_opp.c')
-rw-r--r--drivers/cpufreq/cpufreq_opp.c110
1 files changed, 110 insertions, 0 deletions
diff --git a/drivers/cpufreq/cpufreq_opp.c b/drivers/cpufreq/cpufreq_opp.c
new file mode 100644
index 000000000000..c0c6f4a4eccf
--- /dev/null
+++ b/drivers/cpufreq/cpufreq_opp.c
@@ -0,0 +1,110 @@
+/*
+ * Generic OPP helper interface for CPUFreq drivers
+ *
+ * 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.
+ */
+#include <linux/cpufreq.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/pm_opp.h>
+#include <linux/rcupdate.h>
+#include <linux/slab.h>
+
+/**
+ * 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 list 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 device_opp 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 = kzalloc(sizeof(*freq_table) * (max_opps + 1), GFP_KERNEL);
+ 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;
+ }
+
+ 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);