alistair23-linux/drivers/cpufreq/arm_big_little_dt.c
Linus Torvalds e6b5be2be4 Driver core patches for 3.19-rc1
Here's the set of driver core patches for 3.19-rc1.
 
 They are dominated by the removal of the .owner field in platform
 drivers.  They touch a lot of files, but they are "simple" changes, just
 removing a line in a structure.
 
 Other than that, a few minor driver core and debugfs changes.  There are
 some ath9k patches coming in through this tree that have been acked by
 the wireless maintainers as they relied on the debugfs changes.
 
 Everything has been in linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core update from Greg KH:
 "Here's the set of driver core patches for 3.19-rc1.

  They are dominated by the removal of the .owner field in platform
  drivers.  They touch a lot of files, but they are "simple" changes,
  just removing a line in a structure.

  Other than that, a few minor driver core and debugfs changes.  There
  are some ath9k patches coming in through this tree that have been
  acked by the wireless maintainers as they relied on the debugfs
  changes.

  Everything has been in linux-next for a while"

* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
  Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
  fs: debugfs: add forward declaration for struct device type
  firmware class: Deletion of an unnecessary check before the function call "vunmap"
  firmware loader: fix hung task warning dump
  devcoredump: provide a one-way disable function
  device: Add dev_<level>_once variants
  ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
  ath: use seq_file api for ath9k debugfs files
  debugfs: add helper function to create device related seq_file
  drivers/base: cacheinfo: remove noisy error boot message
  Revert "core: platform: add warning if driver has no owner"
  drivers: base: support cpu cache information interface to userspace via sysfs
  drivers: base: add cpu_device_create to support per-cpu devices
  topology: replace custom attribute macros with standard DEVICE_ATTR*
  cpumask: factor out show_cpumap into separate helper function
  driver core: Fix unbalanced device reference in drivers_probe
  driver core: fix race with userland in device_add()
  sysfs/kernfs: make read requests on pre-alloc files use the buffer.
  sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
  fs: sysfs: return EGBIG on write if offset is larger than file size
  ...
2014-12-14 16:10:09 -08:00

118 lines
2.9 KiB
C

/*
* Generic big.LITTLE CPUFreq Interface driver
*
* It provides necessary ops to arm_big_little cpufreq driver and gets
* Frequency information from Device Tree. Freq table in DT must be in KHz.
*
* Copyright (C) 2013 Linaro.
* Viresh Kumar <viresh.kumar@linaro.org>
*
* 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.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/cpufreq.h>
#include <linux/device.h>
#include <linux/export.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/pm_opp.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/types.h>
#include "arm_big_little.h"
/* get cpu node with valid operating-points */
static struct device_node *get_cpu_node_with_valid_op(int cpu)
{
struct device_node *np = of_cpu_device_node_get(cpu);
if (!of_get_property(np, "operating-points", NULL)) {
of_node_put(np);
np = NULL;
}
return np;
}
static int dt_init_opp_table(struct device *cpu_dev)
{
struct device_node *np;
int ret;
np = of_node_get(cpu_dev->of_node);
if (!np) {
pr_err("failed to find cpu%d node\n", cpu_dev->id);
return -ENOENT;
}
ret = of_init_opp_table(cpu_dev);
of_node_put(np);
return ret;
}
static int dt_get_transition_latency(struct device *cpu_dev)
{
struct device_node *np;
u32 transition_latency = CPUFREQ_ETERNAL;
np = of_node_get(cpu_dev->of_node);
if (!np) {
pr_info("Failed to find cpu node. Use CPUFREQ_ETERNAL transition latency\n");
return CPUFREQ_ETERNAL;
}
of_property_read_u32(np, "clock-latency", &transition_latency);
of_node_put(np);
pr_debug("%s: clock-latency: %d\n", __func__, transition_latency);
return transition_latency;
}
static struct cpufreq_arm_bL_ops dt_bL_ops = {
.name = "dt-bl",
.get_transition_latency = dt_get_transition_latency,
.init_opp_table = dt_init_opp_table,
.free_opp_table = of_free_opp_table,
};
static int generic_bL_probe(struct platform_device *pdev)
{
struct device_node *np;
np = get_cpu_node_with_valid_op(0);
if (!np)
return -ENODEV;
of_node_put(np);
return bL_cpufreq_register(&dt_bL_ops);
}
static int generic_bL_remove(struct platform_device *pdev)
{
bL_cpufreq_unregister(&dt_bL_ops);
return 0;
}
static struct platform_driver generic_bL_platdrv = {
.driver = {
.name = "arm-bL-cpufreq-dt",
},
.probe = generic_bL_probe,
.remove = generic_bL_remove,
};
module_platform_driver(generic_bL_platdrv);
MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
MODULE_DESCRIPTION("Generic ARM big LITTLE cpufreq driver via DT");
MODULE_LICENSE("GPL v2");