drivers/i2c/chips/twl4030-poweroff.c

   1 /*
   2  * linux/drivers/i2c/chips/twl4030_poweroff.c
   3  *
   4  * Power off device
   5  *
   6  * Copyright (C) 2008 Nokia Corporation
   7  *
   8  * Written by Peter De Schrijver <peter.de-schrijver@nokia.com>
   9  *
  10  * This file is subject to the terms and conditions of the GNU General
  11  * Public License. See the file "COPYING" in the main directory of this
  12  * archive for more details.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  22  */
  23
  24 #include <linux/module.h>
  25 #include <linux/pm.h>
  26 #include <linux/i2c/twl4030.h>
  27
  28 #define PWR_P1_SW_EVENTS        0x10
  29 #define PWR_DEVOFF      (1<<0)
  30
  31 static void twl4030_poweroff(void)
  32 {
  33         u8 val;
  34         int err;
  35
  36         err = twl4030_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &val,
  37                                   PWR_P1_SW_EVENTS);
  38         if (err) {
  39                 printk(KERN_WARNING "I2C error %d while reading TWL4030"
  40                                         "PM_MASTER P1_SW_EVENTS\n", err);
  41                 return ;
  42         }
  43
  44         val |= PWR_DEVOFF;
  45
  46         err = twl4030_i2c_write_u8(TWL4030_MODULE_PM_MASTER, val,
  47                                    PWR_P1_SW_EVENTS);
  48
  49         if (err) {
  50                 printk(KERN_WARNING "I2C error %d while writing TWL4030"
  51                                         "PM_MASTER P1_SW_EVENTS\n", err);
  52                 return ;
  53         }
  54
  55         return;
  56 }
  57
  58 static int __init twl4030_poweroff_init(void)
  59 {
  60         pm_power_off = twl4030_poweroff;
  61
  62         return 0;
  63 }
  64
  65 static void __exit twl4030_poweroff_exit(void)
  66 {
  67         pm_power_off = NULL;
  68 }
  69
  70 module_init(twl4030_poweroff_init);
  71 module_exit(twl4030_poweroff_exit);
  72
  73 MODULE_DESCRIPTION("Triton2 device power off");
  74 MODULE_LICENSE("GPL");
  75 MODULE_AUTHOR("Peter De Schrijver");