arch/arm/mach-pxa/mfp-pxa3xx.c

   1 /*
   2  * linux/arch/arm/mach-pxa/mfp.c
   3  *
   4  * PXA3xx Multi-Function Pin Support
   5  *
   6  * Copyright (C) 2007 Marvell Internation Ltd.
   7  *
   8  * 2007-08-21: eric miao <eric.miao@marvell.com>
   9  *             initial version
  10  *
  11  *  This program is free software; you can redistribute it and/or modify
  12  *  it under the terms of the GNU General Public License version 2 as
  13  *  published by the Free Software Foundation.
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/kernel.h>
  18 #include <linux/init.h>
  19 #include <linux/io.h>
  20 #include <linux/sysdev.h>
  21
  22 #include <mach/hardware.h>
  23 #include <mach/mfp-pxa3xx.h>
  24 #include <mach/pxa3xx-regs.h>
  25
  26 #ifdef CONFIG_PM
  27 /*
  28  * Configure the MFPs appropriately for suspend/resume.
  29  * FIXME: this should probably depend on which system state we're
  30  * entering - for instance, we might not want to place MFP pins in
  31  * a pull-down mode if they're an active low chip select, and we're
  32  * just entering standby.
  33  */
  34 static int pxa3xx_mfp_suspend(struct sys_device *d, pm_message_t state)
  35 {
  36         mfp_config_lpm();
  37         return 0;
  38 }
  39
  40 static int pxa3xx_mfp_resume(struct sys_device *d)
  41 {
  42         mfp_config_run();
  43
  44         /* clear RDH bit when MFP settings are restored
  45          *
  46          * NOTE: the last 3 bits DxS are write-1-to-clear so carefully
  47          * preserve them here in case they will be referenced later
  48          */
  49         ASCR &= ~(ASCR_RDH | ASCR_D1S | ASCR_D2S | ASCR_D3S);
  50         return 0;
  51 }
  52 #else
  53 #define pxa3xx_mfp_suspend      NULL
  54 #define pxa3xx_mfp_resume       NULL
  55 #endif
  56
  57 struct sysdev_class pxa3xx_mfp_sysclass = {
  58         .name           = "mfp",
  59         .suspend        = pxa3xx_mfp_suspend,
  60         .resume         = pxa3xx_mfp_resume,
  61 };
  62
  63 static int __init mfp_init_devicefs(void)
  64 {
  65         if (cpu_is_pxa3xx())
  66                 return sysdev_class_register(&pxa3xx_mfp_sysclass);
  67
  68         return 0;
  69 }
  70 postcore_initcall(mfp_init_devicefs);