1*d2912cb1SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 2ce26c5bbSMyungJoo Ham /* 3ce26c5bbSMyungJoo Ham * linux/drivers/devfreq/governor_powersave.c 4ce26c5bbSMyungJoo Ham * 5ce26c5bbSMyungJoo Ham * Copyright (C) 2011 Samsung Electronics 6ce26c5bbSMyungJoo Ham * MyungJoo Ham <myungjoo.ham@samsung.com> 7ce26c5bbSMyungJoo Ham */ 8ce26c5bbSMyungJoo Ham 9ce26c5bbSMyungJoo Ham #include <linux/devfreq.h> 10eff607fdSNishanth Menon #include <linux/module.h> 110b7c328fSXiaoguang Chen #include "governor.h" 12ce26c5bbSMyungJoo Ham 13ce26c5bbSMyungJoo Ham static int devfreq_powersave_func(struct devfreq *df, 14ce26c5bbSMyungJoo Ham unsigned long *freq) 15ce26c5bbSMyungJoo Ham { 16ce26c5bbSMyungJoo Ham /* 17ce26c5bbSMyungJoo Ham * target callback should be able to get ceiling value as 18ce26c5bbSMyungJoo Ham * said in devfreq.h 19ce26c5bbSMyungJoo Ham */ 206ff66e2aSMatthias Kaehlcke *freq = DEVFREQ_MIN_FREQ; 21ce26c5bbSMyungJoo Ham return 0; 22ce26c5bbSMyungJoo Ham } 23ce26c5bbSMyungJoo Ham 247e6fdd4bSRajagopal Venkat static int devfreq_powersave_handler(struct devfreq *devfreq, 257e6fdd4bSRajagopal Venkat unsigned int event, void *data) 260b7c328fSXiaoguang Chen { 277e6fdd4bSRajagopal Venkat int ret = 0; 287e6fdd4bSRajagopal Venkat 297e6fdd4bSRajagopal Venkat if (event == DEVFREQ_GOV_START) { 307e6fdd4bSRajagopal Venkat mutex_lock(&devfreq->lock); 317e6fdd4bSRajagopal Venkat ret = update_devfreq(devfreq); 327e6fdd4bSRajagopal Venkat mutex_unlock(&devfreq->lock); 337e6fdd4bSRajagopal Venkat } 347e6fdd4bSRajagopal Venkat 357e6fdd4bSRajagopal Venkat return ret; 360b7c328fSXiaoguang Chen } 370b7c328fSXiaoguang Chen 381b5c1be2SNishanth Menon static struct devfreq_governor devfreq_powersave = { 39aa7c352fSChanwoo Choi .name = DEVFREQ_GOV_POWERSAVE, 40ce26c5bbSMyungJoo Ham .get_target_freq = devfreq_powersave_func, 417e6fdd4bSRajagopal Venkat .event_handler = devfreq_powersave_handler, 42ce26c5bbSMyungJoo Ham }; 4383116e66SNishanth Menon 4483116e66SNishanth Menon static int __init devfreq_powersave_init(void) 4583116e66SNishanth Menon { 4683116e66SNishanth Menon return devfreq_add_governor(&devfreq_powersave); 4783116e66SNishanth Menon } 4883116e66SNishanth Menon subsys_initcall(devfreq_powersave_init); 4983116e66SNishanth Menon 5083116e66SNishanth Menon static void __exit devfreq_powersave_exit(void) 5183116e66SNishanth Menon { 5283116e66SNishanth Menon int ret; 5383116e66SNishanth Menon 5483116e66SNishanth Menon ret = devfreq_remove_governor(&devfreq_powersave); 5583116e66SNishanth Menon if (ret) 5683116e66SNishanth Menon pr_err("%s: failed remove governor %d\n", __func__, ret); 5783116e66SNishanth Menon 5883116e66SNishanth Menon return; 5983116e66SNishanth Menon } 6083116e66SNishanth Menon module_exit(devfreq_powersave_exit); 61eff607fdSNishanth Menon MODULE_LICENSE("GPL"); 62