+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * drivers/thermal/clock_cooling.c
- *
- * Copyright (C) 2014 Eduardo Valentin <edubezval@gmail.com>
- *
- * Copyright (C) 2013 Texas Instruments Inc.
- * Contact: Eduardo Valentin <eduardo.valentin@ti.com>
- *
- * Highly based on cpufreq_cooling.c.
- * Copyright (C) 2012 Samsung Electronics Co., Ltd(http://www.samsung.com)
- * Copyright (C) 2012 Amit Daniel <amit.kachhap@linaro.org>
- */
-#include <linux/clk.h>
-#include <linux/clock_cooling.h>
-#include <linux/cpufreq.h>
-#include <linux/device.h>
-#include <linux/err.h>
-#include <linux/export.h>
-#include <linux/idr.h>
-#include <linux/mutex.h>
-#include <linux/pm_opp.h>
-#include <linux/slab.h>
-#include <linux/thermal.h>
-
-/**
- * struct clock_cooling_device - data for cooling device with clock
- * @id: unique integer value corresponding to each clock_cooling_device
- * registered.
- * @dev: struct device pointer to the device being used to cool off using
- * clock frequencies.
- * @cdev: thermal_cooling_device pointer to keep track of the
- * registered cooling device.
- * @clk_rate_change_nb: reference to notifier block used to receive clock
- * rate changes.
- * @freq_table: frequency table used to keep track of available frequencies.
- * @clock_state: integer value representing the current state of clock
- * cooling devices.
- * @clock_val: integer value representing the absolute value of the clipped
- * frequency.
- * @clk: struct clk reference used to enforce clock limits.
- * @lock: mutex lock to protect this struct.
- *
- * This structure is required for keeping information of each
- * clock_cooling_device registered. In order to prevent corruption of this a
- * mutex @lock is used.
- */
-struct clock_cooling_device {
- int id;
- struct device *dev;
- struct thermal_cooling_device *cdev;
- struct notifier_block clk_rate_change_nb;
- struct cpufreq_frequency_table *freq_table;
- unsigned long clock_state;
- unsigned long clock_val;
- struct clk *clk;
- struct mutex lock; /* lock to protect the content of this struct */
-};
-#define to_clock_cooling_device(x) \
- container_of(x, struct clock_cooling_device, clk_rate_change_nb)
-static DEFINE_IDA(clock_ida);
-
-/* Below code defines functions to be used for clock as cooling device */
-
-enum clock_cooling_property {
- GET_LEVEL,
- GET_FREQ,
- GET_MAXL,
-};
-
-/**
- * clock_cooling_get_property - fetch a property of interest for a give cpu.
- * @ccdev: clock cooling device reference
- * @input: query parameter
- * @output: query return
- * @property: type of query (frequency, level, max level)
- *
- * This is the common function to
- * 1. get maximum clock cooling states
- * 2. translate frequency to cooling state
- * 3. translate cooling state to frequency
- * Note that the code may be not in good shape
- * but it is written in this way in order to:
- * a) reduce duplicate code as most of the code can be shared.
- * b) make sure the logic is consistent when translating between
- * cooling states and frequencies.
- *
- * Return: 0 on success, -EINVAL when invalid parameters are passed.
- */
-static int clock_cooling_get_property(struct clock_cooling_device *ccdev,
- unsigned long input,
- unsigned long *output,
- enum clock_cooling_property property)
-{
- int i;
- unsigned long max_level = 0, level = 0;
- unsigned int freq = CPUFREQ_ENTRY_INVALID;
- int descend = -1;
- struct cpufreq_frequency_table *pos, *table = ccdev->freq_table;
-
- if (!output)
- return -EINVAL;
-
- if (!table)
- return -EINVAL;
-
- cpufreq_for_each_valid_entry(pos, table) {
- /* ignore duplicate entry */
- if (freq == pos->frequency)
- continue;
-
- /* get the frequency order */
- if (freq != CPUFREQ_ENTRY_INVALID && descend == -1)
- descend = freq > pos->frequency;
-
- freq = pos->frequency;
- max_level++;
- }
-
- /* No valid cpu frequency entry */
- if (max_level == 0)
- return -EINVAL;
-
- /* max_level is an index, not a counter */
- max_level--;
-
- /* get max level */
- if (property == GET_MAXL) {
- *output = max_level;
- return 0;
- }
-
- if (property == GET_FREQ)
- level = descend ? input : (max_level - input);
-
- i = 0;
- cpufreq_for_each_valid_entry(pos, table) {
- /* ignore duplicate entry */
- if (freq == pos->frequency)
- continue;
-
- /* now we have a valid frequency entry */
- freq = pos->frequency;
-
- if (property == GET_LEVEL && (unsigned int)input == freq) {
- /* get level by frequency */
- *output = descend ? i : (max_level - i);
- return 0;
- }
- if (property == GET_FREQ && level == i) {
- /* get frequency by level */
- *output = freq;
- return 0;
- }
- i++;
- }
-
- return -EINVAL;
-}
-
-/**
- * clock_cooling_get_level - return the cooling level of given clock cooling.
- * @cdev: reference of a thermal cooling device of used as clock cooling device
- * @freq: the frequency of interest
- *
- * This function will match the cooling level corresponding to the
- * requested @freq and return it.
- *
- * Return: The matched cooling level on success or THERMAL_CSTATE_INVALID
- * otherwise.
- */
-unsigned long clock_cooling_get_level(struct thermal_cooling_device *cdev,
- unsigned long freq)
-{
- struct clock_cooling_device *ccdev = cdev->devdata;
- unsigned long val;
-
- if (clock_cooling_get_property(ccdev, (unsigned long)freq, &val,
- GET_LEVEL))
- return THERMAL_CSTATE_INVALID;
-
- return val;
-}
-EXPORT_SYMBOL_GPL(clock_cooling_get_level);
-
-/**
- * clock_cooling_get_frequency - get the absolute value of frequency from level.
- * @ccdev: clock cooling device reference
- * @level: cooling level
- *
- * This function matches cooling level with frequency. Based on a cooling level
- * of frequency, equals cooling state of cpu cooling device, it will return
- * the corresponding frequency.
- * e.g level=0 --> 1st MAX FREQ, level=1 ---> 2nd MAX FREQ, .... etc
- *
- * Return: 0 on error, the corresponding frequency otherwise.
- */
-static unsigned long
-clock_cooling_get_frequency(struct clock_cooling_device *ccdev,
- unsigned long level)
-{
- int ret = 0;
- unsigned long freq;
-
- ret = clock_cooling_get_property(ccdev, level, &freq, GET_FREQ);
- if (ret)
- return 0;
-
- return freq;
-}
-
-/**
- * clock_cooling_apply - function to apply frequency clipping.
- * @ccdev: clock_cooling_device pointer containing frequency clipping data.
- * @cooling_state: value of the cooling state.
- *
- * Function used to make sure the clock layer is aware of current thermal
- * limits. The limits are applied by updating the clock rate in case it is
- * higher than the corresponding frequency based on the requested cooling_state.
- *
- * Return: 0 on success, an error code otherwise (-EINVAL in case wrong
- * cooling state).
- */
-static int clock_cooling_apply(struct clock_cooling_device *ccdev,
- unsigned long cooling_state)
-{
- unsigned long clip_freq, cur_freq;
- int ret = 0;
-
- /* Here we write the clipping */
- /* Check if the old cooling action is same as new cooling action */
- if (ccdev->clock_state == cooling_state)
- return 0;
-
- clip_freq = clock_cooling_get_frequency(ccdev, cooling_state);
- if (!clip_freq)
- return -EINVAL;
-
- cur_freq = clk_get_rate(ccdev->clk);
-
- mutex_lock(&ccdev->lock);
- ccdev->clock_state = cooling_state;
- ccdev->clock_val = clip_freq;
- /* enforce clock level */
- if (cur_freq > clip_freq)
- ret = clk_set_rate(ccdev->clk, clip_freq);
- mutex_unlock(&ccdev->lock);
-
- return ret;
-}
-
-/**
- * clock_cooling_clock_notifier - notifier callback on clock rate changes.
- * @nb: struct notifier_block * with callback info.
- * @event: value showing clock event for which this function invoked.
- * @data: callback-specific data
- *
- * Callback to hijack the notification on clock transition.
- * Every time there is a clock change, we intercept all pre change events
- * and block the transition in case the new rate infringes thermal limits.
- *
- * Return: NOTIFY_DONE (success) or NOTIFY_BAD (new_rate > thermal limit).
- */
-static int clock_cooling_clock_notifier(struct notifier_block *nb,
- unsigned long event, void *data)
-{
- struct clk_notifier_data *ndata = data;
- struct clock_cooling_device *ccdev = to_clock_cooling_device(nb);
-
- switch (event) {
- case PRE_RATE_CHANGE:
- /*
- * checks on current state
- * TODO: current method is not best we can find as it
- * allows possibly voltage transitions, in case DVFS
- * layer is also hijacking clock pre notifications.
- */
- if (ndata->new_rate > ccdev->clock_val)
- return NOTIFY_BAD;
- /* fall through */
- case POST_RATE_CHANGE:
- case ABORT_RATE_CHANGE:
- default:
- return NOTIFY_DONE;
- }
-}
-
-/* clock cooling device thermal callback functions are defined below */
-
-/**
- * clock_cooling_get_max_state - callback function to get the max cooling state.
- * @cdev: thermal cooling device pointer.
- * @state: fill this variable with the max cooling state.
- *
- * Callback for the thermal cooling device to return the clock
- * max cooling state.
- *
- * Return: 0 on success, an error code otherwise.
- */
-static int clock_cooling_get_max_state(struct thermal_cooling_device *cdev,
- unsigned long *state)
-{
- struct clock_cooling_device *ccdev = cdev->devdata;
- unsigned long count = 0;
- int ret;
-
- ret = clock_cooling_get_property(ccdev, 0, &count, GET_MAXL);
- if (!ret)
- *state = count;
-
- return ret;
-}
-
-/**
- * clock_cooling_get_cur_state - function to get the current cooling state.
- * @cdev: thermal cooling device pointer.
- * @state: fill this variable with the current cooling state.
- *
- * Callback for the thermal cooling device to return the clock
- * current cooling state.
- *
- * Return: 0 (success)
- */
-static int clock_cooling_get_cur_state(struct thermal_cooling_device *cdev,
- unsigned long *state)
-{
- struct clock_cooling_device *ccdev = cdev->devdata;
-
- *state = ccdev->clock_state;
-
- return 0;
-}
-
-/**
- * clock_cooling_set_cur_state - function to set the current cooling state.
- * @cdev: thermal cooling device pointer.
- * @state: set this variable to the current cooling state.
- *
- * Callback for the thermal cooling device to change the clock cooling
- * current cooling state.
- *
- * Return: 0 on success, an error code otherwise.
- */
-static int clock_cooling_set_cur_state(struct thermal_cooling_device *cdev,
- unsigned long state)
-{
- struct clock_cooling_device *clock_device = cdev->devdata;
-
- return clock_cooling_apply(clock_device, state);
-}
-
-/* Bind clock callbacks to thermal cooling device ops */
-static struct thermal_cooling_device_ops const clock_cooling_ops = {
- .get_max_state = clock_cooling_get_max_state,
- .get_cur_state = clock_cooling_get_cur_state,
- .set_cur_state = clock_cooling_set_cur_state,
-};
-
-/**
- * clock_cooling_register - function to create clock cooling device.
- * @dev: struct device pointer to the device used as clock cooling device.
- * @clock_name: string containing the clock used as cooling mechanism.
- *
- * This interface function registers the clock cooling device with the name
- * "thermal-clock-%x". The cooling device is based on clock frequencies.
- * The struct device is assumed to be capable of DVFS transitions.
- * The OPP layer is used to fetch and fill the available frequencies for
- * the referred device. The ordered frequency table is used to control
- * the clock cooling device cooling states and to limit clock transitions
- * based on the cooling state requested by the thermal framework.
- *
- * Return: a valid struct thermal_cooling_device pointer on success,
- * on failure, it returns a corresponding ERR_PTR().
- */
-struct thermal_cooling_device *
-clock_cooling_register(struct device *dev, const char *clock_name)
-{
- struct thermal_cooling_device *cdev;
- struct clock_cooling_device *ccdev = NULL;
- char dev_name[THERMAL_NAME_LENGTH];
- int ret = 0;
-
- ccdev = devm_kzalloc(dev, sizeof(*ccdev), GFP_KERNEL);
- if (!ccdev)
- return ERR_PTR(-ENOMEM);
-
- mutex_init(&ccdev->lock);
- ccdev->dev = dev;
- ccdev->clk = devm_clk_get(dev, clock_name);
- if (IS_ERR(ccdev->clk))
- return ERR_CAST(ccdev->clk);
-
- ret = ida_simple_get(&clock_ida, 0, 0, GFP_KERNEL);
- if (ret < 0)
- return ERR_PTR(ret);
- ccdev->id = ret;
-
- snprintf(dev_name, sizeof(dev_name), "thermal-clock-%d", ccdev->id);
-
- cdev = thermal_cooling_device_register(dev_name, ccdev,
- &clock_cooling_ops);
- if (IS_ERR(cdev)) {
- ida_simple_remove(&clock_ida, ccdev->id);
- return ERR_PTR(-EINVAL);
- }
- ccdev->cdev = cdev;
- ccdev->clk_rate_change_nb.notifier_call = clock_cooling_clock_notifier;
-
- /* Assuming someone has already filled the opp table for this device */
- ret = dev_pm_opp_init_cpufreq_table(dev, &ccdev->freq_table);
- if (ret) {
- ida_simple_remove(&clock_ida, ccdev->id);
- return ERR_PTR(ret);
- }
- ccdev->clock_state = 0;
- ccdev->clock_val = clock_cooling_get_frequency(ccdev, 0);
-
- clk_notifier_register(ccdev->clk, &ccdev->clk_rate_change_nb);
-
- return cdev;
-}
-EXPORT_SYMBOL_GPL(clock_cooling_register);
-
-/**
- * clock_cooling_unregister - function to remove clock cooling device.
- * @cdev: thermal cooling device pointer.
- *
- * This interface function unregisters the "thermal-clock-%x" cooling device.
- */
-void clock_cooling_unregister(struct thermal_cooling_device *cdev)
-{
- struct clock_cooling_device *ccdev;
-
- if (!cdev)
- return;
-
- ccdev = cdev->devdata;
-
- clk_notifier_unregister(ccdev->clk, &ccdev->clk_rate_change_nb);
- dev_pm_opp_free_cpufreq_table(ccdev->dev, &ccdev->freq_table);
-
- thermal_cooling_device_unregister(ccdev->cdev);
- ida_simple_remove(&clock_ida, ccdev->id);
-}
-EXPORT_SYMBOL_GPL(clock_cooling_unregister);
projects / linux-2.6-microblaze.git / commitdiff