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
 18#include "cm2xxx.h"
 19#include "cm3xxx.h"
 20#include "cm44xx.h"
 21#include "common.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}