1ce26c5bbSMyungJoo Ham /* 2ce26c5bbSMyungJoo Ham * linux/drivers/devfreq/governor_powersave.c 3ce26c5bbSMyungJoo Ham * 4ce26c5bbSMyungJoo Ham * Copyright (C) 2011 Samsung Electronics 5ce26c5bbSMyungJoo Ham * MyungJoo Ham <myungjoo.ham@samsung.com> 6ce26c5bbSMyungJoo Ham * 7ce26c5bbSMyungJoo Ham * This program is free software; you can redistribute it and/or modify 8ce26c5bbSMyungJoo Ham * it under the terms of the GNU General Public License version 2 as 9ce26c5bbSMyungJoo Ham * published by the Free Software Foundation. 10ce26c5bbSMyungJoo Ham */ 11ce26c5bbSMyungJoo Ham 12ce26c5bbSMyungJoo Ham #include <linux/devfreq.h> 13eff607fdSNishanth Menon #include <linux/module.h> 140b7c328fSXiaoguang Chen #include "governor.h" 15ce26c5bbSMyungJoo Ham 16ce26c5bbSMyungJoo Ham static int devfreq_powersave_func(struct devfreq *df, 17ce26c5bbSMyungJoo Ham unsigned long *freq) 18ce26c5bbSMyungJoo Ham { 19ce26c5bbSMyungJoo Ham /* 20ce26c5bbSMyungJoo Ham * target callback should be able to get ceiling value as 21ce26c5bbSMyungJoo Ham * said in devfreq.h 22ce26c5bbSMyungJoo Ham */ 23*6ff66e2aSMatthias Kaehlcke *freq = DEVFREQ_MIN_FREQ; 24ce26c5bbSMyungJoo Ham return 0; 25ce26c5bbSMyungJoo Ham } 26ce26c5bbSMyungJoo Ham 277e6fdd4bSRajagopal Venkat static int devfreq_powersave_handler(struct devfreq *devfreq, 287e6fdd4bSRajagopal Venkat unsigned int event, void *data) 290b7c328fSXiaoguang Chen { 307e6fdd4bSRajagopal Venkat int ret = 0; 317e6fdd4bSRajagopal Venkat 327e6fdd4bSRajagopal Venkat if (event == DEVFREQ_GOV_START) { 337e6fdd4bSRajagopal Venkat mutex_lock(&devfreq->lock); 347e6fdd4bSRajagopal Venkat ret = update_devfreq(devfreq); 357e6fdd4bSRajagopal Venkat mutex_unlock(&devfreq->lock); 367e6fdd4bSRajagopal Venkat } 377e6fdd4bSRajagopal Venkat 387e6fdd4bSRajagopal Venkat return ret; 390b7c328fSXiaoguang Chen } 400b7c328fSXiaoguang Chen 411b5c1be2SNishanth Menon static struct devfreq_governor devfreq_powersave = { 42aa7c352fSChanwoo Choi .name = DEVFREQ_GOV_POWERSAVE, 43ce26c5bbSMyungJoo Ham .get_target_freq = devfreq_powersave_func, 447e6fdd4bSRajagopal Venkat .event_handler = devfreq_powersave_handler, 45ce26c5bbSMyungJoo Ham }; 4683116e66SNishanth Menon 4783116e66SNishanth Menon static int __init devfreq_powersave_init(void) 4883116e66SNishanth Menon { 4983116e66SNishanth Menon return devfreq_add_governor(&devfreq_powersave); 5083116e66SNishanth Menon } 5183116e66SNishanth Menon subsys_initcall(devfreq_powersave_init); 5283116e66SNishanth Menon 5383116e66SNishanth Menon static void __exit devfreq_powersave_exit(void) 5483116e66SNishanth Menon { 5583116e66SNishanth Menon int ret; 5683116e66SNishanth Menon 5783116e66SNishanth Menon ret = devfreq_remove_governor(&devfreq_powersave); 5883116e66SNishanth Menon if (ret) 5983116e66SNishanth Menon pr_err("%s: failed remove governor %d\n", __func__, ret); 6083116e66SNishanth Menon 6183116e66SNishanth Menon return; 6283116e66SNishanth Menon } 6383116e66SNishanth Menon module_exit(devfreq_powersave_exit); 64eff607fdSNishanth Menon MODULE_LICENSE("GPL"); 65