[safe/jmp/linux-2.6] / arch / arm / mach-omap2 / omap_hwmod.c

/*
 * omap_hwmod implementation for OMAP2/3/4
 *
 * Copyright (C) 2009 Nokia Corporation
 * Paul Walmsley
 * With fixes and testing from Kevin Hilman
 *
 * Created in collaboration with (alphabetical order): Benoit Cousson,
 * Kevin Hilman, Tony Lindgren, Rajendra Nayak, Vikram Pandita, Sakari
 * Poussa, Anand Sawant, Santosh Shilimkar, Richard Woodruff
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This code manages "OMAP modules" (on-chip devices) and their
 * integration with Linux device driver and bus code.
 *
 * References:
 * - OMAP2420 Multimedia Processor Silicon Revision 2.1.1, 2.2 (SWPU064)
 * - OMAP2430 Multimedia Device POP Silicon Revision 2.1 (SWPU090)
 * - OMAP34xx Multimedia Device Silicon Revision 3.1 (SWPU108)
 * - OMAP4430 Multimedia Device Silicon Revision 1.0 (SWPU140)
 * - Open Core Protocol Specification 2.2
 *
 * To do:
 * - pin mux handling
 * - handle IO mapping
 * - bus throughput & module latency measurement code
 *
 * XXX add tests at the beginning of each function to ensure the hwmod is
 * in the appropriate state
 * XXX error return values should be checked to ensure that they are
 * appropriate
 */
#undef DEBUG

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/bootmem.h>

#include <plat/common.h>
#include <plat/cpu.h>
#include <plat/clockdomain.h>
#include <plat/powerdomain.h>
#include <plat/clock.h>
#include <plat/omap_hwmod.h>

#include "cm.h"

/* Maximum microseconds to wait for OMAP module to reset */
#define MAX_MODULE_RESET_WAIT           10000

/* Name of the OMAP hwmod for the MPU */
#define MPU_INITIATOR_NAME              "mpu_hwmod"

/* omap_hwmod_list contains all registered struct omap_hwmods */
static LIST_HEAD(omap_hwmod_list);

static DEFINE_MUTEX(omap_hwmod_mutex);

/* mpu_oh: used to add/remove MPU initiator from sleepdep list */
static struct omap_hwmod *mpu_oh;

/* inited: 0 if omap_hwmod_init() has not yet been called; 1 otherwise */
static u8 inited;


/* Private functions */

/**
 * _update_sysc_cache - return the module OCP_SYSCONFIG register, keep copy
 * @oh: struct omap_hwmod *
 *
 * Load the current value of the hwmod OCP_SYSCONFIG register into the
 * struct omap_hwmod for later use.  Returns -EINVAL if the hwmod has no
 * OCP_SYSCONFIG register or 0 upon success.
 */
static int _update_sysc_cache(struct omap_hwmod *oh)
{
        if (!oh->sysconfig) {
                WARN(!oh->sysconfig, "omap_hwmod: %s: cannot read "
                     "OCP_SYSCONFIG: not defined on hwmod\n", oh->name);
                return -EINVAL;
        }

        /* XXX ensure module interface clock is up */

        oh->_sysc_cache = omap_hwmod_readl(oh, oh->sysconfig->sysc_offs);

        oh->_int_flags |= _HWMOD_SYSCONFIG_LOADED;

        return 0;
}

/**
 * _write_sysconfig - write a value to the module's OCP_SYSCONFIG register
 * @v: OCP_SYSCONFIG value to write
 * @oh: struct omap_hwmod *
 *
 * Write @v into the module OCP_SYSCONFIG register, if it has one.  No
 * return value.
 */
static void _write_sysconfig(u32 v, struct omap_hwmod *oh)
{
        if (!oh->sysconfig) {
                WARN(!oh->sysconfig, "omap_hwmod: %s: cannot write "
                     "OCP_SYSCONFIG: not defined on hwmod\n", oh->name);
                return;
        }

        /* XXX ensure module interface clock is up */

        if (oh->_sysc_cache != v) {
                oh->_sysc_cache = v;
                omap_hwmod_writel(v, oh, oh->sysconfig->sysc_offs);
        }
}

/**
 * _set_master_standbymode: set the OCP_SYSCONFIG MIDLEMODE field in @v
 * @oh: struct omap_hwmod *
 * @standbymode: MIDLEMODE field bits
 * @v: pointer to register contents to modify
 *
 * Update the master standby mode bits in @v to be @standbymode for
 * the @oh hwmod.  Does not write to the hardware.  Returns -EINVAL
 * upon error or 0 upon success.
 */
static int _set_master_standbymode(struct omap_hwmod *oh, u8 standbymode,
                                   u32 *v)
{
        if (!oh->sysconfig ||
            !(oh->sysconfig->sysc_flags & SYSC_HAS_MIDLEMODE))
                return -EINVAL;

        *v &= ~SYSC_MIDLEMODE_MASK;
        *v |= __ffs(standbymode) << SYSC_MIDLEMODE_SHIFT;

        return 0;
}

/**
 * _set_slave_idlemode: set the OCP_SYSCONFIG SIDLEMODE field in @v
 * @oh: struct omap_hwmod *
 * @idlemode: SIDLEMODE field bits
 * @v: pointer to register contents to modify
 *
 * Update the slave idle mode bits in @v to be @idlemode for the @oh
 * hwmod.  Does not write to the hardware.  Returns -EINVAL upon error
 * or 0 upon success.
 */
static int _set_slave_idlemode(struct omap_hwmod *oh, u8 idlemode, u32 *v)
{
        if (!oh->sysconfig ||
            !(oh->sysconfig->sysc_flags & SYSC_HAS_SIDLEMODE))
                return -EINVAL;

        *v &= ~SYSC_SIDLEMODE_MASK;
        *v |= __ffs(idlemode) << SYSC_SIDLEMODE_SHIFT;

        return 0;
}

/**
 * _set_clockactivity: set OCP_SYSCONFIG.CLOCKACTIVITY bits in @v
 * @oh: struct omap_hwmod *
 * @clockact: CLOCKACTIVITY field bits
 * @v: pointer to register contents to modify
 *
 * Update the clockactivity mode bits in @v to be @clockact for the
 * @oh hwmod.  Used for additional powersaving on some modules.  Does
 * not write to the hardware.  Returns -EINVAL upon error or 0 upon
 * success.
 */
static int _set_clockactivity(struct omap_hwmod *oh, u8 clockact, u32 *v)
{
        if (!oh->sysconfig ||
            !(oh->sysconfig->sysc_flags & SYSC_HAS_CLOCKACTIVITY))
                return -EINVAL;

        *v &= ~SYSC_CLOCKACTIVITY_MASK;
        *v |= clockact << SYSC_CLOCKACTIVITY_SHIFT;

        return 0;
}

/**
 * _set_softreset: set OCP_SYSCONFIG.CLOCKACTIVITY bits in @v
 * @oh: struct omap_hwmod *
 * @v: pointer to register contents to modify
 *
 * Set the SOFTRESET bit in @v for hwmod @oh.  Returns -EINVAL upon
 * error or 0 upon success.
 */
static int _set_softreset(struct omap_hwmod *oh, u32 *v)
{
        if (!oh->sysconfig ||
            !(oh->sysconfig->sysc_flags & SYSC_HAS_SOFTRESET))
                return -EINVAL;

        *v |= SYSC_SOFTRESET_MASK;

        return 0;
}

/**
 * _enable_wakeup: set OCP_SYSCONFIG.ENAWAKEUP bit in the hardware
 * @oh: struct omap_hwmod *
 *
 * Allow the hardware module @oh to send wakeups.  Returns -EINVAL
 * upon error or 0 upon success.
 */
static int _enable_wakeup(struct omap_hwmod *oh)
{
        u32 v;

        if (!oh->sysconfig ||
            !(oh->sysconfig->sysc_flags & SYSC_HAS_ENAWAKEUP))
                return -EINVAL;

        v = oh->_sysc_cache;
        v |= SYSC_ENAWAKEUP_MASK;
        _write_sysconfig(v, oh);

        /* XXX test pwrdm_get_wken for this hwmod's subsystem */

        oh->_int_flags |= _HWMOD_WAKEUP_ENABLED;

        return 0;
}

/**
 * _disable_wakeup: clear OCP_SYSCONFIG.ENAWAKEUP bit in the hardware
 * @oh: struct omap_hwmod *
 *
 * Prevent the hardware module @oh to send wakeups.  Returns -EINVAL
 * upon error or 0 upon success.
 */
static int _disable_wakeup(struct omap_hwmod *oh)
{
        u32 v;

        if (!oh->sysconfig ||
            !(oh->sysconfig->sysc_flags & SYSC_HAS_ENAWAKEUP))
                return -EINVAL;

        v = oh->_sysc_cache;
        v &= ~SYSC_ENAWAKEUP_MASK;
        _write_sysconfig(v, oh);

        /* XXX test pwrdm_get_wken for this hwmod's subsystem */

        oh->_int_flags &= ~_HWMOD_WAKEUP_ENABLED;

        return 0;
}

/**
 * _add_initiator_dep: prevent @oh from smart-idling while @init_oh is active
 * @oh: struct omap_hwmod *
 *
 * Prevent the hardware module @oh from entering idle while the
 * hardare module initiator @init_oh is active.  Useful when a module
 * will be accessed by a particular initiator (e.g., if a module will
 * be accessed by the IVA, there should be a sleepdep between the IVA
 * initiator and the module).  Only applies to modules in smart-idle
 * mode.  Returns -EINVAL upon error or passes along
 * pwrdm_add_sleepdep() value upon success.
 */
static int _add_initiator_dep(struct omap_hwmod *oh, struct omap_hwmod *init_oh)
{
        if (!oh->_clk)
                return -EINVAL;

        return pwrdm_add_sleepdep(oh->_clk->clkdm->pwrdm.ptr,
                                  init_oh->_clk->clkdm->pwrdm.ptr);
}

/**
 * _del_initiator_dep: allow @oh to smart-idle even if @init_oh is active
 * @oh: struct omap_hwmod *
 *
 * Allow the hardware module @oh to enter idle while the hardare
 * module initiator @init_oh is active.  Useful when a module will not
 * be accessed by a particular initiator (e.g., if a module will not
 * be accessed by the IVA, there should be no sleepdep between the IVA
 * initiator and the module).  Only applies to modules in smart-idle
 * mode.  Returns -EINVAL upon error or passes along
 * pwrdm_add_sleepdep() value upon success.
 */
static int _del_initiator_dep(struct omap_hwmod *oh, struct omap_hwmod *init_oh)
{
        if (!oh->_clk)
                return -EINVAL;

        return pwrdm_del_sleepdep(oh->_clk->clkdm->pwrdm.ptr,
                                  init_oh->_clk->clkdm->pwrdm.ptr);
}

/**
 * _init_main_clk - get a struct clk * for the the hwmod's main functional clk
 * @oh: struct omap_hwmod *
 *
 * Called from _init_clocks().  Populates the @oh _clk (main
 * functional clock pointer) if a main_clk is present.  Returns 0 on
 * success or -EINVAL on error.
 */
static int _init_main_clk(struct omap_hwmod *oh)
{
        struct clk *c;
        int ret = 0;

        if (!oh->clkdev_con_id)
                return 0;

        c = clk_get_sys(oh->clkdev_dev_id, oh->clkdev_con_id);
        WARN(IS_ERR(c), "omap_hwmod: %s: cannot clk_get main_clk %s.%s\n",
             oh->name, oh->clkdev_dev_id, oh->clkdev_con_id);
        if (IS_ERR(c))
                ret = -EINVAL;
        oh->_clk = c;

        return ret;
}

/**
 * _init_interface_clk - get a struct clk * for the the hwmod's interface clks
 * @oh: struct omap_hwmod *
 *
 * Called from _init_clocks().  Populates the @oh OCP slave interface
 * clock pointers.  Returns 0 on success or -EINVAL on error.
 */
static int _init_interface_clks(struct omap_hwmod *oh)
{
        struct omap_hwmod_ocp_if *os;
        struct clk *c;
        int i;
        int ret = 0;

        if (oh->slaves_cnt == 0)
                return 0;

        for (i = 0, os = *oh->slaves; i < oh->slaves_cnt; i++, os++) {
                if (!os->clkdev_con_id)
                        continue;

                c = clk_get_sys(os->clkdev_dev_id, os->clkdev_con_id);
                WARN(IS_ERR(c), "omap_hwmod: %s: cannot clk_get "
                     "interface_clk %s.%s\n", oh->name,
                     os->clkdev_dev_id, os->clkdev_con_id);
                if (IS_ERR(c))
                        ret = -EINVAL;
                os->_clk = c;
        }

        return ret;
}

/**
 * _init_opt_clk - get a struct clk * for the the hwmod's optional clocks
 * @oh: struct omap_hwmod *
 *
 * Called from _init_clocks().  Populates the @oh omap_hwmod_opt_clk
 * clock pointers.  Returns 0 on success or -EINVAL on error.
 */
static int _init_opt_clks(struct omap_hwmod *oh)
{
        struct omap_hwmod_opt_clk *oc;
        struct clk *c;
        int i;
        int ret = 0;

        for (i = oh->opt_clks_cnt, oc = oh->opt_clks; i > 0; i--, oc++) {
                c = clk_get_sys(oc->clkdev_dev_id, oc->clkdev_con_id);
                WARN(IS_ERR(c), "omap_hwmod: %s: cannot clk_get opt_clk "
                     "%s.%s\n", oh->name, oc->clkdev_dev_id,
                     oc->clkdev_con_id);
                if (IS_ERR(c))
                        ret = -EINVAL;
                oc->_clk = c;
        }

        return ret;
}

/**
 * _enable_clocks - enable hwmod main clock and interface clocks
 * @oh: struct omap_hwmod *
 *
 * Enables all clocks necessary for register reads and writes to succeed
 * on the hwmod @oh.  Returns 0.
 */
static int _enable_clocks(struct omap_hwmod *oh)
{
        struct omap_hwmod_ocp_if *os;
        int i;

        pr_debug("omap_hwmod: %s: enabling clocks\n", oh->name);

        if (oh->_clk && !IS_ERR(oh->_clk))
                clk_enable(oh->_clk);

        if (oh->slaves_cnt > 0) {
                for (i = 0, os = *oh->slaves; i < oh->slaves_cnt; i++, os++) {
                        struct clk *c = os->_clk;

                        if (c && !IS_ERR(c) && (os->flags & OCPIF_SWSUP_IDLE))
                                clk_enable(c);
                }
        }

        /* The opt clocks are controlled by the device driver. */

        return 0;
}

/**
 * _disable_clocks - disable hwmod main clock and interface clocks
 * @oh: struct omap_hwmod *
 *
 * Disables the hwmod @oh main functional and interface clocks.  Returns 0.
 */
static int _disable_clocks(struct omap_hwmod *oh)
{
        struct omap_hwmod_ocp_if *os;
        int i;

        pr_debug("omap_hwmod: %s: disabling clocks\n", oh->name);

        if (oh->_clk && !IS_ERR(oh->_clk))
                clk_disable(oh->_clk);

        if (oh->slaves_cnt > 0) {
                for (i = 0, os = *oh->slaves; i < oh->slaves_cnt; i++, os++) {
                        struct clk *c = os->_clk;

                        if (c && !IS_ERR(c) && (os->flags & OCPIF_SWSUP_IDLE))
                                clk_disable(c);
                }
        }

        /* The opt clocks are controlled by the device driver. */

        return 0;
}

/**
 * _find_mpu_port_index - find hwmod OCP slave port ID intended for MPU use
 * @oh: struct omap_hwmod *
 *
 * Returns the array index of the OCP slave port that the MPU
 * addresses the device on, or -EINVAL upon error or not found.
 */
static int _find_mpu_port_index(struct omap_hwmod *oh)
{
        struct omap_hwmod_ocp_if *os;
        int i;
        int found = 0;

        if (!oh || oh->slaves_cnt == 0)
                return -EINVAL;

        for (i = 0, os = *oh->slaves; i < oh->slaves_cnt; i++, os++) {
                if (os->user & OCP_USER_MPU) {
                        found = 1;
                        break;
                }
        }

        if (found)
                pr_debug("omap_hwmod: %s: MPU OCP slave port ID  %d\n",
                         oh->name, i);
        else
                pr_debug("omap_hwmod: %s: no MPU OCP slave port found\n",
                         oh->name);

        return (found) ? i : -EINVAL;
}

/**
 * _find_mpu_rt_base - find hwmod register target base addr accessible by MPU
 * @oh: struct omap_hwmod *
 *
 * Return the virtual address of the base of the register target of
 * device @oh, or NULL on error.
 */
static void __iomem *_find_mpu_rt_base(struct omap_hwmod *oh, u8 index)
{
        struct omap_hwmod_ocp_if *os;
        struct omap_hwmod_addr_space *mem;
        int i;
        int found = 0;
        void __iomem *va_start;

        if (!oh || oh->slaves_cnt == 0)
                return NULL;

        os = *oh->slaves + index;

        for (i = 0, mem = os->addr; i < os->addr_cnt; i++, mem++) {
                if (mem->flags & ADDR_TYPE_RT) {
                        found = 1;
                        break;
                }
        }

        if (found) {
                va_start = ioremap(mem->pa_start, mem->pa_end - mem->pa_start);
                if (!va_start) {
                        pr_err("omap_hwmod: %s: Could not ioremap\n", oh->name);
                        return NULL;
                }
                pr_debug("omap_hwmod: %s: MPU register target at va %p\n",
                         oh->name, va_start);
        } else {
                pr_debug("omap_hwmod: %s: no MPU register target found\n",
                         oh->name);
        }

        return (found) ? va_start : NULL;
}

/**
 * _sysc_enable - try to bring a module out of idle via OCP_SYSCONFIG
 * @oh: struct omap_hwmod *
 *
 * If module is marked as SWSUP_SIDLE, force the module out of slave
 * idle; otherwise, configure it for smart-idle.  If module is marked
 * as SWSUP_MSUSPEND, force the module out of master standby;
 * otherwise, configure it for smart-standby.  No return value.
 */
static void _sysc_enable(struct omap_hwmod *oh)
{
        u8 idlemode;
        u32 v;

        if (!oh->sysconfig)
                return;

        v = oh->_sysc_cache;

        if (oh->sysconfig->sysc_flags & SYSC_HAS_SIDLEMODE) {
                idlemode = (oh->flags & HWMOD_SWSUP_SIDLE) ?
                        HWMOD_IDLEMODE_NO : HWMOD_IDLEMODE_SMART;
                _set_slave_idlemode(oh, idlemode, &v);
        }

        if (oh->sysconfig->sysc_flags & SYSC_HAS_MIDLEMODE) {
                idlemode = (oh->flags & HWMOD_SWSUP_MSTANDBY) ?
                        HWMOD_IDLEMODE_NO : HWMOD_IDLEMODE_SMART;
                _set_master_standbymode(oh, idlemode, &v);
        }

        /* XXX OCP AUTOIDLE bit? */

        if (oh->flags & HWMOD_SET_DEFAULT_CLOCKACT &&
            oh->sysconfig->sysc_flags & SYSC_HAS_CLOCKACTIVITY)
                _set_clockactivity(oh, oh->sysconfig->clockact, &v);

        _write_sysconfig(v, oh);
}

/**
 * _sysc_idle - try to put a module into idle via OCP_SYSCONFIG
 * @oh: struct omap_hwmod *
 *
 * If module is marked as SWSUP_SIDLE, force the module into slave
 * idle; otherwise, configure it for smart-idle.  If module is marked
 * as SWSUP_MSUSPEND, force the module into master standby; otherwise,
 * configure it for smart-standby.  No return value.
 */
static void _sysc_idle(struct omap_hwmod *oh)
{
        u8 idlemode;
        u32 v;

        if (!oh->sysconfig)
                return;

        v = oh->_sysc_cache;

        if (oh->sysconfig->sysc_flags & SYSC_HAS_SIDLEMODE) {
                idlemode = (oh->flags & HWMOD_SWSUP_SIDLE) ?
                        HWMOD_IDLEMODE_FORCE : HWMOD_IDLEMODE_SMART;
                _set_slave_idlemode(oh, idlemode, &v);
        }

        if (oh->sysconfig->sysc_flags & SYSC_HAS_MIDLEMODE) {
                idlemode = (oh->flags & HWMOD_SWSUP_MSTANDBY) ?
                        HWMOD_IDLEMODE_FORCE : HWMOD_IDLEMODE_SMART;
                _set_master_standbymode(oh, idlemode, &v);
        }

        _write_sysconfig(v, oh);
}

/**
 * _sysc_shutdown - force a module into idle via OCP_SYSCONFIG
 * @oh: struct omap_hwmod *
 *
 * Force the module into slave idle and master suspend. No return
 * value.
 */
static void _sysc_shutdown(struct omap_hwmod *oh)
{
        u32 v;

        if (!oh->sysconfig)
                return;

        v = oh->_sysc_cache;

        if (oh->sysconfig->sysc_flags & SYSC_HAS_SIDLEMODE)
                _set_slave_idlemode(oh, HWMOD_IDLEMODE_FORCE, &v);

        if (oh->sysconfig->sysc_flags & SYSC_HAS_MIDLEMODE)
                _set_master_standbymode(oh, HWMOD_IDLEMODE_FORCE, &v);

        /* XXX clear OCP AUTOIDLE bit? */

        _write_sysconfig(v, oh);
}

/**
 * _lookup - find an omap_hwmod by name
 * @name: find an omap_hwmod by name
 *
 * Return a pointer to an omap_hwmod by name, or NULL if not found.
 * Caller must hold omap_hwmod_mutex.
 */
static struct omap_hwmod *_lookup(const char *name)
{
        struct omap_hwmod *oh, *temp_oh;

        oh = NULL;

        list_for_each_entry(temp_oh, &omap_hwmod_list, node) {
                if (!strcmp(name, temp_oh->name)) {
                        oh = temp_oh;
                        break;
                }
        }

        return oh;
}

/**
 * _init_clocks - clk_get() all clocks associated with this hwmod
 * @oh: struct omap_hwmod *
 *
 * Called by omap_hwmod_late_init() (after omap2_clk_init()).
 * Resolves all clock names embedded in the hwmod.  Must be called
 * with omap_hwmod_mutex held.  Returns -EINVAL if the omap_hwmod
 * has not yet been registered or if the clocks have already been
 * initialized, 0 on success, or a non-zero error on failure.
 */
static int _init_clocks(struct omap_hwmod *oh)
{
        int ret = 0;

        if (!oh || (oh->_state != _HWMOD_STATE_REGISTERED))
                return -EINVAL;

        pr_debug("omap_hwmod: %s: looking up clocks\n", oh->name);

        ret |= _init_main_clk(oh);
        ret |= _init_interface_clks(oh);
        ret |= _init_opt_clks(oh);

        oh->_state = _HWMOD_STATE_CLKS_INITED;

        return ret;
}

/**
 * _wait_target_ready - wait for a module to leave slave idle
 * @oh: struct omap_hwmod *
 *
 * Wait for a module @oh to leave slave idle.  Returns 0 if the module
 * does not have an IDLEST bit or if the module successfully leaves
 * slave idle; otherwise, pass along the return value of the
 * appropriate *_cm_wait_module_ready() function.
 */
static int _wait_target_ready(struct omap_hwmod *oh)
{
        struct omap_hwmod_ocp_if *os;
        int ret;

        if (!oh)
                return -EINVAL;

        if (oh->_int_flags & _HWMOD_NO_MPU_PORT)
                return 0;

        os = *oh->slaves + oh->_mpu_port_index;

        if (!(os->flags & OCPIF_HAS_IDLEST))
                return 0;

        /* XXX check module SIDLEMODE */

        /* XXX check clock enable states */

        if (cpu_is_omap24xx() || cpu_is_omap34xx()) {
                ret = omap2_cm_wait_module_ready(oh->prcm.omap2.module_offs,
                                                 oh->prcm.omap2.idlest_reg_id,
                                                 oh->prcm.omap2.idlest_idle_bit);
#if 0
        } else if (cpu_is_omap44xx()) {
                ret = omap4_cm_wait_module_ready(oh->prcm.omap4.module_offs,
                                                 oh->prcm.omap4.device_offs);
#endif
        } else {
                BUG();
        };

        return ret;
}

/**
 * _reset - reset an omap_hwmod
 * @oh: struct omap_hwmod *
 *
 * Resets an omap_hwmod @oh via the OCP_SYSCONFIG bit.  hwmod must be
 * enabled for this to work.  Must be called with omap_hwmod_mutex
 * held.  Returns -EINVAL if the hwmod cannot be reset this way or if
 * the hwmod is in the wrong state, -ETIMEDOUT if the module did not
 * reset in time, or 0 upon success.
 */
static int _reset(struct omap_hwmod *oh)
{
        u32 r, v;
        int c = 0;

        if (!oh->sysconfig ||
            !(oh->sysconfig->sysc_flags & SYSC_HAS_SOFTRESET) ||
            (oh->sysconfig->sysc_flags & SYSS_MISSING))
                return -EINVAL;

        /* clocks must be on for this operation */
        if (oh->_state != _HWMOD_STATE_ENABLED) {
                WARN(1, "omap_hwmod: %s: reset can only be entered from "
                     "enabled state\n", oh->name);
                return -EINVAL;
        }

        pr_debug("omap_hwmod: %s: resetting\n", oh->name);

        v = oh->_sysc_cache;
        r = _set_softreset(oh, &v);
        if (r)
                return r;
        _write_sysconfig(v, oh);

        omap_test_timeout((omap_hwmod_readl(oh, oh->sysconfig->syss_offs) &
                           SYSS_RESETDONE_MASK),
                          MAX_MODULE_RESET_WAIT, c);

        if (c == MAX_MODULE_RESET_WAIT)
                WARN(1, "omap_hwmod: %s: failed to reset in %d usec\n",
                     oh->name, MAX_MODULE_RESET_WAIT);
        else
                pr_debug("omap_hwmod: %s: reset in %d usec\n", oh->name, c);

        /*
         * XXX add _HWMOD_STATE_WEDGED for modules that don't come back from
         * _wait_target_ready() or _reset()
         */

        return (c == MAX_MODULE_RESET_WAIT) ? -ETIMEDOUT : 0;
}

/**
 * _enable - enable an omap_hwmod
 * @oh: struct omap_hwmod *
 *
 * Enables an omap_hwmod @oh such that the MPU can access the hwmod's
 * register target.  Must be called with omap_hwmod_mutex held.
 * Returns -EINVAL if the hwmod is in the wrong state or passes along
 * the return value of _wait_target_ready().
 */
static int _enable(struct omap_hwmod *oh)
{
        int r;

        if (oh->_state != _HWMOD_STATE_INITIALIZED &&
            oh->_state != _HWMOD_STATE_IDLE &&
            oh->_state != _HWMOD_STATE_DISABLED) {
                WARN(1, "omap_hwmod: %s: enabled state can only be entered "
                     "from initialized, idle, or disabled state\n", oh->name);
                return -EINVAL;
        }

        pr_debug("omap_hwmod: %s: enabling\n", oh->name);

        /* XXX mux balls */

        _add_initiator_dep(oh, mpu_oh);
        _enable_clocks(oh);

        if (oh->sysconfig) {
                if (!(oh->_int_flags & _HWMOD_SYSCONFIG_LOADED))
                        _update_sysc_cache(oh);
                _sysc_enable(oh);
        }

        r = _wait_target_ready(oh);
        if (!r)
                oh->_state = _HWMOD_STATE_ENABLED;

        return r;
}

/**
 * _idle - idle an omap_hwmod
 * @oh: struct omap_hwmod *
 *
 * Idles an omap_hwmod @oh.  This should be called once the hwmod has
 * no further work.  Returns -EINVAL if the hwmod is in the wrong
 * state or returns 0.
 */
static int _idle(struct omap_hwmod *oh)
{
        if (oh->_state != _HWMOD_STATE_ENABLED) {
                WARN(1, "omap_hwmod: %s: idle state can only be entered from "
                     "enabled state\n", oh->name);
                return -EINVAL;
        }

        pr_debug("omap_hwmod: %s: idling\n", oh->name);

        if (oh->sysconfig)
                _sysc_idle(oh);
        _del_initiator_dep(oh, mpu_oh);
        _disable_clocks(oh);

        oh->_state = _HWMOD_STATE_IDLE;

        return 0;
}

/**
 * _shutdown - shutdown an omap_hwmod
 * @oh: struct omap_hwmod *
 *
 * Shut down an omap_hwmod @oh.  This should be called when the driver
 * used for the hwmod is removed or unloaded or if the driver is not
 * used by the system.  Returns -EINVAL if the hwmod is in the wrong
 * state or returns 0.
 */
static int _shutdown(struct omap_hwmod *oh)
{
        if (oh->_state != _HWMOD_STATE_IDLE &&
            oh->_state != _HWMOD_STATE_ENABLED) {
                WARN(1, "omap_hwmod: %s: disabled state can only be entered "
                     "from idle, or enabled state\n", oh->name);
                return -EINVAL;
        }

        pr_debug("omap_hwmod: %s: disabling\n", oh->name);

        if (oh->sysconfig)
                _sysc_shutdown(oh);
        _del_initiator_dep(oh, mpu_oh);
        /* XXX what about the other system initiators here? DMA, tesla, d2d */
        _disable_clocks(oh);
        /* XXX Should this code also force-disable the optional clocks? */

        /* XXX mux any associated balls to safe mode */

        oh->_state = _HWMOD_STATE_DISABLED;

        return 0;
}

/**
 * _write_clockact_lock - set the module's clockactivity bits
 * @oh: struct omap_hwmod *
 * @clockact: CLOCKACTIVITY field bits
 *
 * Writes the CLOCKACTIVITY bits @clockact to the hwmod @oh
 * OCP_SYSCONFIG register.  Returns -EINVAL if the hwmod is in the
 * wrong state or returns 0.
 */
static int _write_clockact_lock(struct omap_hwmod *oh, u8 clockact)
{
        u32 v;

        if (!oh->sysconfig ||
            !(oh->sysconfig->sysc_flags & SYSC_HAS_CLOCKACTIVITY))
                return -EINVAL;

        mutex_lock(&omap_hwmod_mutex);
        v = oh->_sysc_cache;
        _set_clockactivity(oh, clockact, &v);
        _write_sysconfig(v, oh);
        mutex_unlock(&omap_hwmod_mutex);

        return 0;
}


/**
 * _setup - do initial configuration of omap_hwmod
 * @oh: struct omap_hwmod *
 *
 * Writes the CLOCKACTIVITY bits @clockact to the hwmod @oh
 * OCP_SYSCONFIG register.  Must be called with omap_hwmod_mutex
 * held.  Returns -EINVAL if the hwmod is in the wrong state or returns
 * 0.
 */
static int _setup(struct omap_hwmod *oh)
{
        struct omap_hwmod_ocp_if *os;
        int i;

        if (!oh)
                return -EINVAL;

        /* Set iclk autoidle mode */
        if (oh->slaves_cnt > 0) {
                for (i = 0, os = *oh->slaves; i < oh->slaves_cnt; i++, os++) {
                        struct clk *c = os->_clk;

                        if (!c || IS_ERR(c))
                                continue;

                        if (os->flags & OCPIF_SWSUP_IDLE) {
                                /* XXX omap_iclk_deny_idle(c); */
                        } else {
                                /* XXX omap_iclk_allow_idle(c); */
                                clk_enable(c);
                        }
                }
        }

        oh->_state = _HWMOD_STATE_INITIALIZED;

        _enable(oh);

        if (!(oh->flags & HWMOD_INIT_NO_RESET)) {
                /*
                 * XXX Do the OCP_SYSCONFIG bits need to be
                 * reprogrammed after a reset?  If not, then this can
                 * be removed.  If they do, then probably the
                 * _enable() function should be split to avoid the
                 * rewrite of the OCP_SYSCONFIG register.
                 */
                if (oh->sysconfig) {
                        _update_sysc_cache(oh);
                        _sysc_enable(oh);
                }
        }

        if (!(oh->flags & HWMOD_INIT_NO_IDLE))
                _idle(oh);

        return 0;
}



/* Public functions */

u32 omap_hwmod_readl(struct omap_hwmod *oh, u16 reg_offs)
{
        return __raw_readl(oh->_rt_va + reg_offs);
}

void omap_hwmod_writel(u32 v, struct omap_hwmod *oh, u16 reg_offs)
{
        __raw_writel(v, oh->_rt_va + reg_offs);
}

/**
 * omap_hwmod_register - register a struct omap_hwmod
 * @oh: struct omap_hwmod *
 *
 * Registers the omap_hwmod @oh.  Returns -EEXIST if an omap_hwmod already
 * has been registered by the same name; -EINVAL if the omap_hwmod is in the
 * wrong state, or 0 on success.
 *
 * XXX The data should be copied into bootmem, so the original data
 * should be marked __initdata and freed after init.  This would allow
 * unneeded omap_hwmods to be freed on multi-OMAP configurations.  Note
 * that the copy process would be relatively complex due to the large number
 * of substructures.
 */
int omap_hwmod_register(struct omap_hwmod *oh)
{
        int ret, ms_id;

        if (!oh || (oh->_state != _HWMOD_STATE_UNKNOWN))
                return -EINVAL;

        mutex_lock(&omap_hwmod_mutex);

        pr_debug("omap_hwmod: %s: registering\n", oh->name);

        if (_lookup(oh->name)) {
                ret = -EEXIST;
                goto ohr_unlock;
        }

        ms_id = _find_mpu_port_index(oh);
        if (!IS_ERR_VALUE(ms_id)) {
                oh->_mpu_port_index = ms_id;
                oh->_rt_va = _find_mpu_rt_base(oh, oh->_mpu_port_index);
        } else {
                oh->_int_flags |= _HWMOD_NO_MPU_PORT;
        }

        list_add_tail(&oh->node, &omap_hwmod_list);

        oh->_state = _HWMOD_STATE_REGISTERED;

        ret = 0;

ohr_unlock:
        mutex_unlock(&omap_hwmod_mutex);
        return ret;
}

/**
 * omap_hwmod_lookup - look up a registered omap_hwmod by name
 * @name: name of the omap_hwmod to look up
 *
 * Given a @name of an omap_hwmod, return a pointer to the registered
 * struct omap_hwmod *, or NULL upon error.
 */
struct omap_hwmod *omap_hwmod_lookup(const char *name)
{
        struct omap_hwmod *oh;

        if (!name)
                return NULL;

        mutex_lock(&omap_hwmod_mutex);
        oh = _lookup(name);
        mutex_unlock(&omap_hwmod_mutex);

        return oh;
}

/**
 * omap_hwmod_for_each - call function for each registered omap_hwmod
 * @fn: pointer to a callback function
 *
 * Call @fn for each registered omap_hwmod, passing @data to each
 * function.  @fn must return 0 for success or any other value for
 * failure.  If @fn returns non-zero, the iteration across omap_hwmods
 * will stop and the non-zero return value will be passed to the
 * caller of omap_hwmod_for_each().  @fn is called with
 * omap_hwmod_for_each() held.
 */
int omap_hwmod_for_each(int (*fn)(struct omap_hwmod *oh))
{
        struct omap_hwmod *temp_oh;
        int ret;

        if (!fn)
                return -EINVAL;

        mutex_lock(&omap_hwmod_mutex);
        list_for_each_entry(temp_oh, &omap_hwmod_list, node) {
                ret = (*fn)(temp_oh);
                if (ret)
                        break;
        }
        mutex_unlock(&omap_hwmod_mutex);

        return ret;
}


/**
 * omap_hwmod_init - init omap_hwmod code and register hwmods
 * @ohs: pointer to an array of omap_hwmods to register
 *
 * Intended to be called early in boot before the clock framework is
 * initialized.  If @ohs is not null, will register all omap_hwmods
 * listed in @ohs that are valid for this chip.  Returns -EINVAL if
 * omap_hwmod_init() has already been called or 0 otherwise.
 */
int omap_hwmod_init(struct omap_hwmod **ohs)
{
        struct omap_hwmod *oh;
        int r;

        if (inited)
                return -EINVAL;

        inited = 1;

        if (!ohs)
                return 0;

        oh = *ohs;
        while (oh) {
                if (omap_chip_is(oh->omap_chip)) {
                        r = omap_hwmod_register(oh);
                        WARN(r, "omap_hwmod: %s: omap_hwmod_register returned "
                             "%d\n", oh->name, r);
                }
                oh = *++ohs;
        }

        return 0;
}

/**
 * omap_hwmod_late_init - do some post-clock framework initialization
 *
 * Must be called after omap2_clk_init().  Resolves the struct clk names
 * to struct clk pointers for each registered omap_hwmod.  Also calls
 * _setup() on each hwmod.  Returns 0.
 */
int omap_hwmod_late_init(void)
{
        int r;

        /* XXX check return value */
        r = omap_hwmod_for_each(_init_clocks);
        WARN(r, "omap_hwmod: omap_hwmod_late_init(): _init_clocks failed\n");

        mpu_oh = omap_hwmod_lookup(MPU_INITIATOR_NAME);
        WARN(!mpu_oh, "omap_hwmod: could not find MPU initiator hwmod %s\n",
             MPU_INITIATOR_NAME);

        omap_hwmod_for_each(_setup);

        return 0;
}

/**
 * omap_hwmod_unregister - unregister an omap_hwmod
 * @oh: struct omap_hwmod *
 *
 * Unregisters a previously-registered omap_hwmod @oh.  There's probably
 * no use case for this, so it is likely to be removed in a later version.
 *
 * XXX Free all of the bootmem-allocated structures here when that is
 * implemented.  Make it clear that core code is the only code that is
 * expected to unregister modules.
 */
int omap_hwmod_unregister(struct omap_hwmod *oh)
{
        if (!oh)
                return -EINVAL;

        pr_debug("omap_hwmod: %s: unregistering\n", oh->name);

        mutex_lock(&omap_hwmod_mutex);
        iounmap(oh->_rt_va);
        list_del(&oh->node);
        mutex_unlock(&omap_hwmod_mutex);

        return 0;
}

/**
 * omap_hwmod_enable - enable an omap_hwmod
 * @oh: struct omap_hwmod *
 *
 * Enable an omap_hwomd @oh.  Intended to be called by omap_device_enable().
 * Returns -EINVAL on error or passes along the return value from _enable().
 */
int omap_hwmod_enable(struct omap_hwmod *oh)
{
        int r;

        if (!oh)
                return -EINVAL;

        mutex_lock(&omap_hwmod_mutex);
        r = _enable(oh);
        mutex_unlock(&omap_hwmod_mutex);

        return r;
}

/**
 * omap_hwmod_idle - idle an omap_hwmod
 * @oh: struct omap_hwmod *
 *
 * Idle an omap_hwomd @oh.  Intended to be called by omap_device_idle().
 * Returns -EINVAL on error or passes along the return value from _idle().
 */
int omap_hwmod_idle(struct omap_hwmod *oh)
{
        if (!oh)
                return -EINVAL;

        mutex_lock(&omap_hwmod_mutex);
        _idle(oh);
        mutex_unlock(&omap_hwmod_mutex);

        return 0;
}

/**
 * omap_hwmod_shutdown - shutdown an omap_hwmod
 * @oh: struct omap_hwmod *
 *
 * Shutdown an omap_hwomd @oh.  Intended to be called by
 * omap_device_shutdown().  Returns -EINVAL on error or passes along
 * the return value from _shutdown().
 */
int omap_hwmod_shutdown(struct omap_hwmod *oh)
{
        if (!oh)
                return -EINVAL;

        mutex_lock(&omap_hwmod_mutex);
        _shutdown(oh);
        mutex_unlock(&omap_hwmod_mutex);

        return 0;
}

/**
 * omap_hwmod_enable_clocks - enable main_clk, all interface clocks
 * @oh: struct omap_hwmod *oh
 *
 * Intended to be called by the omap_device code.
 */
int omap_hwmod_enable_clocks(struct omap_hwmod *oh)
{
        mutex_lock(&omap_hwmod_mutex);
        _enable_clocks(oh);
        mutex_unlock(&omap_hwmod_mutex);

        return 0;
}

/**
 * omap_hwmod_disable_clocks - disable main_clk, all interface clocks
 * @oh: struct omap_hwmod *oh
 *
 * Intended to be called by the omap_device code.
 */
int omap_hwmod_disable_clocks(struct omap_hwmod *oh)
{
        mutex_lock(&omap_hwmod_mutex);
        _disable_clocks(oh);
        mutex_unlock(&omap_hwmod_mutex);

        return 0;
}

/**
 * omap_hwmod_ocp_barrier - wait for posted writes against the hwmod to complete
 * @oh: struct omap_hwmod *oh
 *
 * Intended to be called by drivers and core code when all posted
 * writes to a device must complete before continuing further
 * execution (for example, after clearing some device IRQSTATUS
 * register bits)
 *
 * XXX what about targets with multiple OCP threads?
 */
void omap_hwmod_ocp_barrier(struct omap_hwmod *oh)
{
        BUG_ON(!oh);

        if (!oh->sysconfig || !oh->sysconfig->sysc_flags) {
                WARN(1, "omap_device: %s: OCP barrier impossible due to "
                      "device configuration\n", oh->name);
                return;
        }

        /*
         * Forces posted writes to complete on the OCP thread handling
         * register writes
         */
        omap_hwmod_readl(oh, oh->sysconfig->sysc_offs);
}

/**
 * omap_hwmod_reset - reset the hwmod
 * @oh: struct omap_hwmod *
 *
 * Under some conditions, a driver may wish to reset the entire device.
 * Called from omap_device code.  Returns -EINVAL on error or passes along
 * the return value from _reset()/_enable().
 */
int omap_hwmod_reset(struct omap_hwmod *oh)
{
        int r;

        if (!oh || !(oh->_state & _HWMOD_STATE_ENABLED))
                return -EINVAL;

        mutex_lock(&omap_hwmod_mutex);
        r = _reset(oh);
        if (!r)
                r = _enable(oh);
        mutex_unlock(&omap_hwmod_mutex);

        return r;
}

/**
 * omap_hwmod_count_resources - count number of struct resources needed by hwmod
 * @oh: struct omap_hwmod *
 * @res: pointer to the first element of an array of struct resource to fill
 *
 * Count the number of struct resource array elements necessary to
 * contain omap_hwmod @oh resources.  Intended to be called by code
 * that registers omap_devices.  Intended to be used to determine the
 * size of a dynamically-allocated struct resource array, before
 * calling omap_hwmod_fill_resources().  Returns the number of struct
 * resource array elements needed.
 *
 * XXX This code is not optimized.  It could attempt to merge adjacent
 * resource IDs.
 *
 */
int omap_hwmod_count_resources(struct omap_hwmod *oh)
{
        int ret, i;

        ret = oh->mpu_irqs_cnt + oh->sdma_chs_cnt;

        for (i = 0; i < oh->slaves_cnt; i++)
                ret += (*oh->slaves + i)->addr_cnt;

        return ret;
}

/**
 * omap_hwmod_fill_resources - fill struct resource array with hwmod data
 * @oh: struct omap_hwmod *
 * @res: pointer to the first element of an array of struct resource to fill
 *
 * Fill the struct resource array @res with resource data from the
 * omap_hwmod @oh.  Intended to be called by code that registers
 * omap_devices.  See also omap_hwmod_count_resources().  Returns the
 * number of array elements filled.
 */
int omap_hwmod_fill_resources(struct omap_hwmod *oh, struct resource *res)
{
        int i, j;
        int r = 0;

        /* For each IRQ, DMA, memory area, fill in array.*/

        for (i = 0; i < oh->mpu_irqs_cnt; i++) {
                (res + r)->start = *(oh->mpu_irqs + i);
                (res + r)->end = *(oh->mpu_irqs + i);
                (res + r)->flags = IORESOURCE_IRQ;
                r++;
        }

        for (i = 0; i < oh->sdma_chs_cnt; i++) {
                (res + r)->name = (oh->sdma_chs + i)->name;
                (res + r)->start = (oh->sdma_chs + i)->dma_ch;
                (res + r)->end = (oh->sdma_chs + i)->dma_ch;
                (res + r)->flags = IORESOURCE_DMA;
                r++;
        }

        for (i = 0; i < oh->slaves_cnt; i++) {
                struct omap_hwmod_ocp_if *os;

                os = *oh->slaves + i;

                for (j = 0; j < os->addr_cnt; j++) {
                        (res + r)->start = (os->addr + j)->pa_start;
                        (res + r)->end = (os->addr + j)->pa_end;
                        (res + r)->flags = IORESOURCE_MEM;
                        r++;
                }
        }

        return r;
}

/**
 * omap_hwmod_get_pwrdm - return pointer to this module's main powerdomain
 * @oh: struct omap_hwmod *
 *
 * Return the powerdomain pointer associated with the OMAP module
 * @oh's main clock.  If @oh does not have a main clk, return the
 * powerdomain associated with the interface clock associated with the
 * module's MPU port. (XXX Perhaps this should use the SDMA port
 * instead?)  Returns NULL on error, or a struct powerdomain * on
 * success.
 */
struct powerdomain *omap_hwmod_get_pwrdm(struct omap_hwmod *oh)
{
        struct clk *c;

        if (!oh)
                return NULL;

        if (oh->_clk) {
                c = oh->_clk;
        } else {
                if (oh->_int_flags & _HWMOD_NO_MPU_PORT)
                        return NULL;
                c = oh->slaves[oh->_mpu_port_index]->_clk;
        }

        return c->clkdm->pwrdm.ptr;

}

/**
 * omap_hwmod_add_initiator_dep - add sleepdep from @init_oh to @oh
 * @oh: struct omap_hwmod *
 * @init_oh: struct omap_hwmod * (initiator)
 *
 * Add a sleep dependency between the initiator @init_oh and @oh.
 * Intended to be called by DSP/Bridge code via platform_data for the
 * DSP case; and by the DMA code in the sDMA case.  DMA code, *Bridge
 * code needs to add/del initiator dependencies dynamically
 * before/after accessing a device.  Returns the return value from
 * _add_initiator_dep().
 *
 * XXX Keep a usecount in the clockdomain code
 */
int omap_hwmod_add_initiator_dep(struct omap_hwmod *oh,
                                 struct omap_hwmod *init_oh)
{
        return _add_initiator_dep(oh, init_oh);
}

/*
 * XXX what about functions for drivers to save/restore ocp_sysconfig
 * for context save/restore operations?
 */

/**
 * omap_hwmod_del_initiator_dep - remove sleepdep from @init_oh to @oh
 * @oh: struct omap_hwmod *
 * @init_oh: struct omap_hwmod * (initiator)
 *
 * Remove a sleep dependency between the initiator @init_oh and @oh.
 * Intended to be called by DSP/Bridge code via platform_data for the
 * DSP case; and by the DMA code in the sDMA case.  DMA code, *Bridge
 * code needs to add/del initiator dependencies dynamically
 * before/after accessing a device.  Returns the return value from
 * _del_initiator_dep().
 *
 * XXX Keep a usecount in the clockdomain code
 */
int omap_hwmod_del_initiator_dep(struct omap_hwmod *oh,
                                 struct omap_hwmod *init_oh)
{
        return _del_initiator_dep(oh, init_oh);
}

/**
 * omap_hwmod_set_clockact_none - set clockactivity test to BOTH
 * @oh: struct omap_hwmod *
 *
 * On some modules, this function can affect the wakeup latency vs.
 * power consumption balance.  Intended to be called by the
 * omap_device layer.  Passes along the return value from
 * _write_clockact_lock().
 */
int omap_hwmod_set_clockact_both(struct omap_hwmod *oh)
{
        return _write_clockact_lock(oh, CLOCKACT_TEST_BOTH);
}

/**
 * omap_hwmod_set_clockact_none - set clockactivity test to MAIN
 * @oh: struct omap_hwmod *
 *
 * On some modules, this function can affect the wakeup latency vs.
 * power consumption balance.  Intended to be called by the
 * omap_device layer.  Passes along the return value from
 * _write_clockact_lock().
 */
int omap_hwmod_set_clockact_main(struct omap_hwmod *oh)
{
        return _write_clockact_lock(oh, CLOCKACT_TEST_MAIN);
}

/**
 * omap_hwmod_set_clockact_none - set clockactivity test to ICLK
 * @oh: struct omap_hwmod *
 *
 * On some modules, this function can affect the wakeup latency vs.
 * power consumption balance.  Intended to be called by the
 * omap_device layer.  Passes along the return value from
 * _write_clockact_lock().
 */
int omap_hwmod_set_clockact_iclk(struct omap_hwmod *oh)
{
        return _write_clockact_lock(oh, CLOCKACT_TEST_ICLK);
}

/**
 * omap_hwmod_set_clockact_none - set clockactivity test to NONE
 * @oh: struct omap_hwmod *
 *
 * On some modules, this function can affect the wakeup latency vs.
 * power consumption balance.  Intended to be called by the
 * omap_device layer.  Passes along the return value from
 * _write_clockact_lock().
 */
int omap_hwmod_set_clockact_none(struct omap_hwmod *oh)
{
        return _write_clockact_lock(oh, CLOCKACT_TEST_NONE);
}

/**
 * omap_hwmod_enable_wakeup - allow device to wake up the system
 * @oh: struct omap_hwmod *
 *
 * Sets the module OCP socket ENAWAKEUP bit to allow the module to
 * send wakeups to the PRCM.  Eventually this should sets PRCM wakeup
 * registers to cause the PRCM to receive wakeup events from the
 * module.  Does not set any wakeup routing registers beyond this
 * point - if the module is to wake up any other module or subsystem,
 * that must be set separately.  Called by omap_device code.  Returns
 * -EINVAL on error or 0 upon success.
 */
int omap_hwmod_enable_wakeup(struct omap_hwmod *oh)
{
        if (!oh->sysconfig ||
            !(oh->sysconfig->sysc_flags & SYSC_HAS_ENAWAKEUP))
                return -EINVAL;

        mutex_lock(&omap_hwmod_mutex);
        _enable_wakeup(oh);
        mutex_unlock(&omap_hwmod_mutex);

        return 0;
}

/**
 * omap_hwmod_disable_wakeup - prevent device from waking the system
 * @oh: struct omap_hwmod *
 *
 * Clears the module OCP socket ENAWAKEUP bit to prevent the module
 * from sending wakeups to the PRCM.  Eventually this should clear
 * PRCM wakeup registers to cause the PRCM to ignore wakeup events
 * from the module.  Does not set any wakeup routing registers beyond
 * this point - if the module is to wake up any other module or
 * subsystem, that must be set separately.  Called by omap_device
 * code.  Returns -EINVAL on error or 0 upon success.
 */
int omap_hwmod_disable_wakeup(struct omap_hwmod *oh)
{
        if (!oh->sysconfig ||
            !(oh->sysconfig->sysc_flags & SYSC_HAS_ENAWAKEUP))
                return -EINVAL;

        mutex_lock(&omap_hwmod_mutex);
        _disable_wakeup(oh);
        mutex_unlock(&omap_hwmod_mutex);

        return 0;
}