arch/arm/mach-omap2/cm.c

   1 /*
   2  * OMAP2/3 CM module functions
   3  *
   4  * Copyright (C) 2009 Nokia Corporation
   5  * Paul Walmsley
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/types.h>
  15 #include <linux/delay.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/list.h>
  18 #include <linux/errno.h>
  19 #include <linux/err.h>
  20 #include <linux/io.h>
  21
  22 #include <asm/atomic.h>
  23
  24 #include <plat/common.h>
  25
  26 #include "cm.h"
  27 #include "cm-regbits-24xx.h"
  28 #include "cm-regbits-34xx.h"
  29
  30 static const u8 cm_idlest_offs[] = {
  31         CM_IDLEST1, CM_IDLEST2, OMAP2430_CM_IDLEST3
  32 };
  33
  34 /**
  35  * omap2_cm_wait_idlest_ready - wait for a module to leave idle or standby
  36  * @prcm_mod: PRCM module offset
  37  * @idlest_id: CM_IDLESTx register ID (i.e., x = 1, 2, 3)
  38  * @idlest_shift: shift of the bit in the CM_IDLEST* register to check
  39  *
  40  * XXX document
  41  */
  42 int omap2_cm_wait_module_ready(s16 prcm_mod, u8 idlest_id, u8 idlest_shift)
  43 {
  44         int ena = 0, i = 0;
  45         u8 cm_idlest_reg;
  46         u32 mask;
  47
  48         if (!idlest_id || (idlest_id > ARRAY_SIZE(cm_idlest_offs)))
  49                 return -EINVAL;
  50
  51         cm_idlest_reg = cm_idlest_offs[idlest_id - 1];
  52
  53         mask = 1 << idlest_shift;
  54
  55         if (cpu_is_omap24xx())
  56                 ena = mask;
  57         else if (cpu_is_omap34xx())
  58                 ena = 0;
  59         else
  60                 BUG();
  61
  62         /* XXX should be OMAP2 CM */
  63         omap_test_timeout(((cm_read_mod_reg(prcm_mod, cm_idlest_reg) & mask) == ena),
  64                           MAX_MODULE_READY_TIME, i);
  65
  66         return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY;
  67 }
  68