arch/arm/mach-omap2/prcm.c

   1 /*
   2  * linux/arch/arm/mach-omap2/prcm.c
   3  *
   4  * OMAP 24xx Power Reset and Clock Management (PRCM) functions
   5  *
   6  * Copyright (C) 2005 Nokia Corporation
   7  *
   8  * Written by Tony Lindgren <tony.lindgren@nokia.com>
   9  *
  10  * Some pieces of code Copyright (C) 2005 Texas Instruments, Inc.
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License version 2 as
  14  * published by the Free Software Foundation.
  15  */
  16 #include <linux/module.h>
  17 #include <linux/init.h>
  18 #include <linux/clk.h>
  19 #include <linux/io.h>
  20
  21 #include <asm/arch/common.h>
  22 #include <asm/arch/prcm.h>
  23
  24 #include "clock.h"
  25 #include "prm.h"
  26 #include "prm-regbits-24xx.h"
  27
  28 static void __iomem *prm_base;
  29 static void __iomem *cm_base;
  30
  31 u32 omap_prcm_get_reset_sources(void)
  32 {
  33         /* XXX This presumably needs modification for 34XX */
  34         return prm_read_mod_reg(WKUP_MOD, RM_RSTST) & 0x7f;
  35 }
  36 EXPORT_SYMBOL(omap_prcm_get_reset_sources);
  37
  38 /* Resets clock rates and reboots the system. Only called from system.h */
  39 void omap_prcm_arch_reset(char mode)
  40 {
  41         s16 prcm_offs;
  42         omap2_clk_prepare_for_reboot();
  43
  44         if (cpu_is_omap24xx())
  45                 prcm_offs = WKUP_MOD;
  46         else if (cpu_is_omap34xx())
  47                 prcm_offs = OMAP3430_GR_MOD;
  48         else
  49                 WARN_ON(1);
  50
  51         prm_set_mod_reg_bits(OMAP_RST_DPLL3, prcm_offs, RM_RSTCTRL);
  52 }
  53
  54 static inline u32 __omap_prcm_read(void __iomem *base, s16 module, u16 reg)
  55 {
  56         BUG_ON(!base);
  57         return __raw_readl(base + module + reg);
  58 }
  59
  60 static inline void __omap_prcm_write(u32 value, void __iomem *base,
  61                                                 s16 module, u16 reg)
  62 {
  63         BUG_ON(!base);
  64         __raw_writel(value, base + module + reg);
  65 }
  66
  67 /* Read a register in a PRM module */
  68 u32 prm_read_mod_reg(s16 module, u16 idx)
  69 {
  70         return __omap_prcm_read(prm_base, module, idx);
  71 }
  72 EXPORT_SYMBOL(prm_read_mod_reg);
  73
  74 /* Write into a register in a PRM module */
  75 void prm_write_mod_reg(u32 val, s16 module, u16 idx)
  76 {
  77         __omap_prcm_write(val, prm_base, module, idx);
  78 }
  79 EXPORT_SYMBOL(prm_write_mod_reg);
  80
  81 /* Read-modify-write a register in a PRM module. Caller must lock */
  82 u32 prm_rmw_mod_reg_bits(u32 mask, u32 bits, s16 module, s16 idx)
  83 {
  84         u32 v;
  85
  86         v = prm_read_mod_reg(module, idx);
  87         v &= ~mask;
  88         v |= bits;
  89         prm_write_mod_reg(v, module, idx);
  90
  91         return v;
  92 }
  93 EXPORT_SYMBOL(prm_rmw_mod_reg_bits);
  94
  95 /* Read a register in a CM module */
  96 u32 cm_read_mod_reg(s16 module, u16 idx)
  97 {
  98         return __omap_prcm_read(cm_base, module, idx);
  99 }
 100 EXPORT_SYMBOL(cm_read_mod_reg);
 101
 102 /* Write into a register in a CM module */
 103 void cm_write_mod_reg(u32 val, s16 module, u16 idx)
 104 {
 105         __omap_prcm_write(val, cm_base, module, idx);
 106 }
 107 EXPORT_SYMBOL(cm_write_mod_reg);
 108
 109 /* Read-modify-write a register in a CM module. Caller must lock */
 110 u32 cm_rmw_mod_reg_bits(u32 mask, u32 bits, s16 module, s16 idx)
 111 {
 112         u32 v;
 113
 114         v = cm_read_mod_reg(module, idx);
 115         v &= ~mask;
 116         v |= bits;
 117         cm_write_mod_reg(v, module, idx);
 118
 119         return v;
 120 }
 121 EXPORT_SYMBOL(cm_rmw_mod_reg_bits);
 122
 123 void __init omap2_set_globals_prcm(struct omap_globals *omap2_globals)
 124 {
 125         prm_base = omap2_globals->prm;
 126         cm_base = omap2_globals->cm;
 127 }