LXR linux/arch/arm/mach-omap2/cm

   1/*
   2 * OMAP2+ common Clock Management (CM) IP block functions
   3 *
   4 * Copyright (C) 2012 Texas Instruments, Inc.
   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 * XXX This code should eventually be moved to a CM driver.
  12 */
  13
  14#include <linux/kernel.h>
  15#include <linux/init.h>
  16#include <linux/errno.h>
  17#include <linux/bug.h>
  18
  19#include "cm2xxx.h"
  20#include "cm3xxx.h"
  21#include "cm44xx.h"
  22
  23/*
  24 * cm_ll_data: function pointers to SoC-specific implementations of
  25 * common CM functions
  26 */
  27static struct cm_ll_data null_cm_ll_data;
  28static struct cm_ll_data *cm_ll_data = &null_cm_ll_data;
  29
  30/* cm_base: base virtual address of the CM IP block */
  31void __iomem *cm_base;
  32
  33/* cm2_base: base virtual address of the CM2 IP block (OMAP44xx only) */
  34void __iomem *cm2_base;
  35
  36/**
  37 * omap2_set_globals_cm - set the CM/CM2 base addresses (for early use)
  38 * @cm: CM base virtual address
  39 * @cm2: CM2 base virtual address (if present on the booted SoC)
  40 *
  41 * XXX Will be replaced when the PRM/CM drivers are completed.
  42 */
  43void __init omap2_set_globals_cm(void __iomem *cm, void __iomem *cm2)
  44{
  45        cm_base = cm;
  46        cm2_base = cm2;
  47}
  48
  49/**
  50 * cm_split_idlest_reg - split CM_IDLEST reg addr into its components
  51 * @idlest_reg: CM_IDLEST* virtual address
  52 * @prcm_inst: pointer to an s16 to return the PRCM instance offset
  53 * @idlest_reg_id: pointer to a u8 to return the CM_IDLESTx register ID
  54 *
  55 * Given an absolute CM_IDLEST register address @idlest_reg, passes
  56 * the PRCM instance offset and IDLEST register ID back to the caller
  57 * via the @prcm_inst and @idlest_reg_id.  Returns -EINVAL upon error,
  58 * or 0 upon success.  XXX This function is only needed until absolute
  59 * register addresses are removed from the OMAP struct clk records.
  60 */
  61int cm_split_idlest_reg(void __iomem *idlest_reg, s16 *prcm_inst,
  62                        u8 *idlest_reg_id)
  63{
  64        if (!cm_ll_data->split_idlest_reg) {
  65                WARN_ONCE(1, "cm: %s: no low-level function defined\n",
  66                          __func__);
  67                return -EINVAL;
  68        }
  69
  70        return cm_ll_data->split_idlest_reg(idlest_reg, prcm_inst,
  71                                           idlest_reg_id);
  72}
  73
  74/**
  75 * cm_wait_module_ready - wait for a module to leave idle or standby
  76 * @prcm_mod: PRCM module offset
  77 * @idlest_id: CM_IDLESTx register ID (i.e., x = 1, 2, 3)
  78 * @idlest_shift: shift of the bit in the CM_IDLEST* register to check
  79 *
  80 * Wait for the PRCM to indicate that the module identified by
  81 * (@prcm_mod, @idlest_id, @idlest_shift) is clocked.  Return 0 upon
  82 * success, -EBUSY if the module doesn't enable in time, or -EINVAL if
  83 * no per-SoC wait_module_ready() function pointer has been registered
  84 * or if the idlest register is unknown on the SoC.
  85 */
  86int cm_wait_module_ready(s16 prcm_mod, u8 idlest_id, u8 idlest_shift)
  87{
  88        if (!cm_ll_data->wait_module_ready) {
  89                WARN_ONCE(1, "cm: %s: no low-level function defined\n",
  90                          __func__);
  91                return -EINVAL;
  92        }
  93
  94        return cm_ll_data->wait_module_ready(prcm_mod, idlest_id, idlest_shift);
  95}
  96
  97/**
  98 * cm_register - register per-SoC low-level data with the CM
  99 * @cld: low-level per-SoC OMAP CM data & function pointers to register
 100 *
 101 * Register per-SoC low-level OMAP CM data and function pointers with
 102 * the OMAP CM common interface.  The caller must keep the data
 103 * pointed to by @cld valid until it calls cm_unregister() and
 104 * it returns successfully.  Returns 0 upon success, -EINVAL if @cld
 105 * is NULL, or -EEXIST if cm_register() has already been called
 106 * without an intervening cm_unregister().
 107 */
 108int cm_register(struct cm_ll_data *cld)
 109{
 110        if (!cld)
 111                return -EINVAL;
 112
 113        if (cm_ll_data != &null_cm_ll_data)
 114                return -EEXIST;
 115
 116        cm_ll_data = cld;
 117
 118        return 0;
 119}
 120
 121/**
 122 * cm_unregister - unregister per-SoC low-level data & function pointers
 123 * @cld: low-level per-SoC OMAP CM data & function pointers to unregister
 124 *
 125 * Unregister per-SoC low-level OMAP CM data and function pointers
 126 * that were previously registered with cm_register().  The
 127 * caller may not destroy any of the data pointed to by @cld until
 128 * this function returns successfully.  Returns 0 upon success, or
 129 * -EINVAL if @cld is NULL or if @cld does not match the struct
 130 * cm_ll_data * previously registered by cm_register().
 131 */
 132int cm_unregister(struct cm_ll_data *cld)
 133{
 134        if (!cld || cm_ll_data != cld)
 135                return -EINVAL;
 136
 137        cm_ll_data = &null_cm_ll_data;
 138
 139        return 0;
 140}
 141