diff options
Diffstat (limited to 'arch/arm/mach-omap2/clockdomain.c')
| -rw-r--r-- | arch/arm/mach-omap2/clockdomain.c | 890 |
1 files changed, 890 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/clockdomain.c b/arch/arm/mach-omap2/clockdomain.c new file mode 100644 index 00000000..6cb6c032 --- /dev/null +++ b/arch/arm/mach-omap2/clockdomain.c @@ -0,0 +1,890 @@ +/* + * OMAP2/3/4 clockdomain framework functions + * + * Copyright (C) 2008-2010 Texas Instruments, Inc. + * Copyright (C) 2008-2010 Nokia Corporation + * + * Written by Paul Walmsley and Jouni Högander + * Added OMAP4 specific support by Abhijit Pagare <abhijitpagare@ti.com> + * + * 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. + */ +#undef DEBUG + +#include <linux/kernel.h> +#include <linux/device.h> +#include <linux/list.h> +#include <linux/errno.h> +#include <linux/delay.h> +#include <linux/clk.h> +#include <linux/limits.h> +#include <linux/err.h> + +#include <linux/io.h> + +#include <linux/bitops.h> + +#include <plat/clock.h> +#include "clockdomain.h" + +/* clkdm_list contains all registered struct clockdomains */ +static LIST_HEAD(clkdm_list); + +/* array of clockdomain deps to be added/removed when clkdm in hwsup mode */ +static struct clkdm_autodep *autodeps; + +static struct clkdm_ops *arch_clkdm; + +/* Private functions */ + +static struct clockdomain *_clkdm_lookup(const char *name) +{ + struct clockdomain *clkdm, *temp_clkdm; + + if (!name) + return NULL; + + clkdm = NULL; + + list_for_each_entry(temp_clkdm, &clkdm_list, node) { + if (!strcmp(name, temp_clkdm->name)) { + clkdm = temp_clkdm; + break; + } + } + + return clkdm; +} + +/** + * _clkdm_register - register a clockdomain + * @clkdm: struct clockdomain * to register + * + * Adds a clockdomain to the internal clockdomain list. + * Returns -EINVAL if given a null pointer, -EEXIST if a clockdomain is + * already registered by the provided name, or 0 upon success. + */ +static int _clkdm_register(struct clockdomain *clkdm) +{ + struct powerdomain *pwrdm; + + if (!clkdm || !clkdm->name) + return -EINVAL; + + if (!omap_chip_is(clkdm->omap_chip)) + return -EINVAL; + + pwrdm = pwrdm_lookup(clkdm->pwrdm.name); + if (!pwrdm) { + pr_err("clockdomain: %s: powerdomain %s does not exist\n", + clkdm->name, clkdm->pwrdm.name); + return -EINVAL; + } + clkdm->pwrdm.ptr = pwrdm; + + /* Verify that the clockdomain is not already registered */ + if (_clkdm_lookup(clkdm->name)) + return -EEXIST; + + list_add(&clkdm->node, &clkdm_list); + + pwrdm_add_clkdm(pwrdm, clkdm); + + pr_debug("clockdomain: registered %s\n", clkdm->name); + + return 0; +} + +/* _clkdm_deps_lookup - look up the specified clockdomain in a clkdm list */ +static struct clkdm_dep *_clkdm_deps_lookup(struct clockdomain *clkdm, + struct clkdm_dep *deps) +{ + struct clkdm_dep *cd; + + if (!clkdm || !deps || !omap_chip_is(clkdm->omap_chip)) + return ERR_PTR(-EINVAL); + + for (cd = deps; cd->clkdm_name; cd++) { + if (!omap_chip_is(cd->omap_chip)) + continue; + + if (!cd->clkdm && cd->clkdm_name) + cd->clkdm = _clkdm_lookup(cd->clkdm_name); + + if (cd->clkdm == clkdm) + break; + } + + if (!cd->clkdm_name) + return ERR_PTR(-ENOENT); + + return cd; +} + +/* + * _autodep_lookup - resolve autodep clkdm names to clkdm pointers; store + * @autodep: struct clkdm_autodep * to resolve + * + * Resolve autodep clockdomain names to clockdomain pointers via + * clkdm_lookup() and store the pointers in the autodep structure. An + * "autodep" is a clockdomain sleep/wakeup dependency that is + * automatically added and removed whenever clocks in the associated + * clockdomain are enabled or disabled (respectively) when the + * clockdomain is in hardware-supervised mode. Meant to be called + * once at clockdomain layer initialization, since these should remain + * fixed for a particular architecture. No return value. + * + * XXX autodeps are deprecated and should be removed at the earliest + * opportunity + */ +static void _autodep_lookup(struct clkdm_autodep *autodep) +{ + struct clockdomain *clkdm; + + if (!autodep) + return; + + if (!omap_chip_is(autodep->omap_chip)) + return; + + clkdm = clkdm_lookup(autodep->clkdm.name); + if (!clkdm) { + pr_err("clockdomain: autodeps: clockdomain %s does not exist\n", + autodep->clkdm.name); + clkdm = ERR_PTR(-ENOENT); + } + autodep->clkdm.ptr = clkdm; +} + +/* + * _clkdm_add_autodeps - add auto sleepdeps/wkdeps to clkdm upon clock enable + * @clkdm: struct clockdomain * + * + * Add the "autodep" sleep & wakeup dependencies to clockdomain 'clkdm' + * in hardware-supervised mode. Meant to be called from clock framework + * when a clock inside clockdomain 'clkdm' is enabled. No return value. + * + * XXX autodeps are deprecated and should be removed at the earliest + * opportunity + */ +void _clkdm_add_autodeps(struct clockdomain *clkdm) +{ + struct clkdm_autodep *autodep; + + if (!autodeps || clkdm->flags & CLKDM_NO_AUTODEPS) + return; + + for (autodep = autodeps; autodep->clkdm.ptr; autodep++) { + if (IS_ERR(autodep->clkdm.ptr)) + continue; + + if (!omap_chip_is(autodep->omap_chip)) + continue; + + pr_debug("clockdomain: adding %s sleepdep/wkdep for " + "clkdm %s\n", autodep->clkdm.ptr->name, + clkdm->name); + + clkdm_add_sleepdep(clkdm, autodep->clkdm.ptr); + clkdm_add_wkdep(clkdm, autodep->clkdm.ptr); + } +} + +/* + * _clkdm_add_autodeps - remove auto sleepdeps/wkdeps from clkdm + * @clkdm: struct clockdomain * + * + * Remove the "autodep" sleep & wakeup dependencies from clockdomain 'clkdm' + * in hardware-supervised mode. Meant to be called from clock framework + * when a clock inside clockdomain 'clkdm' is disabled. No return value. + * + * XXX autodeps are deprecated and should be removed at the earliest + * opportunity + */ +void _clkdm_del_autodeps(struct clockdomain *clkdm) +{ + struct clkdm_autodep *autodep; + + if (!autodeps || clkdm->flags & CLKDM_NO_AUTODEPS) + return; + + for (autodep = autodeps; autodep->clkdm.ptr; autodep++) { + if (IS_ERR(autodep->clkdm.ptr)) + continue; + + if (!omap_chip_is(autodep->omap_chip)) + continue; + + pr_debug("clockdomain: removing %s sleepdep/wkdep for " + "clkdm %s\n", autodep->clkdm.ptr->name, + clkdm->name); + + clkdm_del_sleepdep(clkdm, autodep->clkdm.ptr); + clkdm_del_wkdep(clkdm, autodep->clkdm.ptr); + } +} + +/** + * _resolve_clkdm_deps() - resolve clkdm_names in @clkdm_deps to clkdms + * @clkdm: clockdomain that we are resolving dependencies for + * @clkdm_deps: ptr to array of struct clkdm_deps to resolve + * + * Iterates through @clkdm_deps, looking up the struct clockdomain named by + * clkdm_name and storing the clockdomain pointer in the struct clkdm_dep. + * No return value. + */ +static void _resolve_clkdm_deps(struct clockdomain *clkdm, + struct clkdm_dep *clkdm_deps) +{ + struct clkdm_dep *cd; + + for (cd = clkdm_deps; cd && cd->clkdm_name; cd++) { + if (!omap_chip_is(cd->omap_chip)) + continue; + if (cd->clkdm) + continue; + cd->clkdm = _clkdm_lookup(cd->clkdm_name); + + WARN(!cd->clkdm, "clockdomain: %s: could not find clkdm %s while resolving dependencies - should never happen", + clkdm->name, cd->clkdm_name); + } +} + +/* Public functions */ + +/** + * clkdm_init - set up the clockdomain layer + * @clkdms: optional pointer to an array of clockdomains to register + * @init_autodeps: optional pointer to an array of autodeps to register + * @custom_funcs: func pointers for arch specific implementations + * + * Set up internal state. If a pointer to an array of clockdomains + * @clkdms was supplied, loop through the list of clockdomains, + * register all that are available on the current platform. Similarly, + * if a pointer to an array of clockdomain autodependencies + * @init_autodeps was provided, register those. No return value. + */ +void clkdm_init(struct clockdomain **clkdms, + struct clkdm_autodep *init_autodeps, + struct clkdm_ops *custom_funcs) +{ + struct clockdomain **c = NULL; + struct clockdomain *clkdm; + struct clkdm_autodep *autodep = NULL; + + if (!custom_funcs) + WARN(1, "No custom clkdm functions registered\n"); + else + arch_clkdm = custom_funcs; + + if (clkdms) + for (c = clkdms; *c; c++) + _clkdm_register(*c); + + autodeps = init_autodeps; + if (autodeps) + for (autodep = autodeps; autodep->clkdm.ptr; autodep++) + _autodep_lookup(autodep); + + /* + * Put all clockdomains into software-supervised mode; PM code + * should later enable hardware-supervised mode as appropriate + */ + list_for_each_entry(clkdm, &clkdm_list, node) { + if (clkdm->flags & CLKDM_CAN_FORCE_WAKEUP) + clkdm_wakeup(clkdm); + else if (clkdm->flags & CLKDM_CAN_DISABLE_AUTO) + clkdm_deny_idle(clkdm); + + _resolve_clkdm_deps(clkdm, clkdm->wkdep_srcs); + clkdm_clear_all_wkdeps(clkdm); + + _resolve_clkdm_deps(clkdm, clkdm->sleepdep_srcs); + clkdm_clear_all_sleepdeps(clkdm); + } +} + +/** + * clkdm_lookup - look up a clockdomain by name, return a pointer + * @name: name of clockdomain + * + * Find a registered clockdomain by its name @name. Returns a pointer + * to the struct clockdomain if found, or NULL otherwise. + */ +struct clockdomain *clkdm_lookup(const char *name) +{ + struct clockdomain *clkdm, *temp_clkdm; + + if (!name) + return NULL; + + clkdm = NULL; + + list_for_each_entry(temp_clkdm, &clkdm_list, node) { + if (!strcmp(name, temp_clkdm->name)) { + clkdm = temp_clkdm; + break; + } + } + + return clkdm; +} + +/** + * clkdm_for_each - call function on each registered clockdomain + * @fn: callback function * + * + * Call the supplied function @fn for each registered clockdomain. + * The callback function @fn can return anything but 0 to bail + * out early from the iterator. The callback function is called with + * the clkdm_mutex held, so no clockdomain structure manipulation + * functions should be called from the callback, although hardware + * clockdomain control functions are fine. Returns the last return + * value of the callback function, which should be 0 for success or + * anything else to indicate failure; or -EINVAL if the function pointer + * is null. + */ +int clkdm_for_each(int (*fn)(struct clockdomain *clkdm, void *user), + void *user) +{ + struct clockdomain *clkdm; + int ret = 0; + + if (!fn) + return -EINVAL; + + list_for_each_entry(clkdm, &clkdm_list, node) { + ret = (*fn)(clkdm, user); + if (ret) + break; + } + + return ret; +} + + +/** + * clkdm_get_pwrdm - return a ptr to the pwrdm that this clkdm resides in + * @clkdm: struct clockdomain * + * + * Return a pointer to the struct powerdomain that the specified clockdomain + * @clkdm exists in, or returns NULL if @clkdm is NULL. + */ +struct powerdomain *clkdm_get_pwrdm(struct clockdomain *clkdm) +{ + if (!clkdm) + return NULL; + + return clkdm->pwrdm.ptr; +} + + +/* Hardware clockdomain control */ + +/** + * clkdm_add_wkdep - add a wakeup dependency from clkdm2 to clkdm1 + * @clkdm1: wake this struct clockdomain * up (dependent) + * @clkdm2: when this struct clockdomain * wakes up (source) + * + * When the clockdomain represented by @clkdm2 wakes up, wake up + * @clkdm1. Implemented in hardware on the OMAP, this feature is + * designed to reduce wakeup latency of the dependent clockdomain @clkdm1. + * Returns -EINVAL if presented with invalid clockdomain pointers, + * -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or 0 upon + * success. + */ +int clkdm_add_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2) +{ + struct clkdm_dep *cd; + int ret = 0; + + if (!clkdm1 || !clkdm2) + return -EINVAL; + + cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs); + if (IS_ERR(cd)) + ret = PTR_ERR(cd); + + if (!arch_clkdm || !arch_clkdm->clkdm_add_wkdep) + ret = -EINVAL; + + if (ret) { + pr_debug("clockdomain: hardware cannot set/clear wake up of " + "%s when %s wakes up\n", clkdm1->name, clkdm2->name); + return ret; + } + + if (atomic_inc_return(&cd->wkdep_usecount) == 1) { + pr_debug("clockdomain: hardware will wake up %s when %s wakes " + "up\n", clkdm1->name, clkdm2->name); + + ret = arch_clkdm->clkdm_add_wkdep(clkdm1, clkdm2); + } + + return ret; +} + +/** + * clkdm_del_wkdep - remove a wakeup dependency from clkdm2 to clkdm1 + * @clkdm1: wake this struct clockdomain * up (dependent) + * @clkdm2: when this struct clockdomain * wakes up (source) + * + * Remove a wakeup dependency causing @clkdm1 to wake up when @clkdm2 + * wakes up. Returns -EINVAL if presented with invalid clockdomain + * pointers, -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or + * 0 upon success. + */ +int clkdm_del_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2) +{ + struct clkdm_dep *cd; + int ret = 0; + + if (!clkdm1 || !clkdm2) + return -EINVAL; + + cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs); + if (IS_ERR(cd)) + ret = PTR_ERR(cd); + + if (!arch_clkdm || !arch_clkdm->clkdm_del_wkdep) + ret = -EINVAL; + + if (ret) { + pr_debug("clockdomain: hardware cannot set/clear wake up of " + "%s when %s wakes up\n", clkdm1->name, clkdm2->name); + return ret; + } + + if (atomic_dec_return(&cd->wkdep_usecount) == 0) { + pr_debug("clockdomain: hardware will no longer wake up %s " + "after %s wakes up\n", clkdm1->name, clkdm2->name); + + ret = arch_clkdm->clkdm_del_wkdep(clkdm1, clkdm2); + } + + return ret; +} + +/** + * clkdm_read_wkdep - read wakeup dependency state from clkdm2 to clkdm1 + * @clkdm1: wake this struct clockdomain * up (dependent) + * @clkdm2: when this struct clockdomain * wakes up (source) + * + * Return 1 if a hardware wakeup dependency exists wherein @clkdm1 will be + * awoken when @clkdm2 wakes up; 0 if dependency is not set; -EINVAL + * if either clockdomain pointer is invalid; or -ENOENT if the hardware + * is incapable. + * + * REVISIT: Currently this function only represents software-controllable + * wakeup dependencies. Wakeup dependencies fixed in hardware are not + * yet handled here. + */ +int clkdm_read_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2) +{ + struct clkdm_dep *cd; + int ret = 0; + + if (!clkdm1 || !clkdm2) + return -EINVAL; + + cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs); + if (IS_ERR(cd)) + ret = PTR_ERR(cd); + + if (!arch_clkdm || !arch_clkdm->clkdm_read_wkdep) + ret = -EINVAL; + + if (ret) { + pr_debug("clockdomain: hardware cannot set/clear wake up of " + "%s when %s wakes up\n", clkdm1->name, clkdm2->name); + return ret; + } + + /* XXX It's faster to return the atomic wkdep_usecount */ + return arch_clkdm->clkdm_read_wkdep(clkdm1, clkdm2); +} + +/** + * clkdm_clear_all_wkdeps - remove all wakeup dependencies from target clkdm + * @clkdm: struct clockdomain * to remove all wakeup dependencies from + * + * Remove all inter-clockdomain wakeup dependencies that could cause + * @clkdm to wake. Intended to be used during boot to initialize the + * PRCM to a known state, after all clockdomains are put into swsup idle + * and woken up. Returns -EINVAL if @clkdm pointer is invalid, or + * 0 upon success. + */ +int clkdm_clear_all_wkdeps(struct clockdomain *clkdm) +{ + if (!clkdm) + return -EINVAL; + + if (!arch_clkdm || !arch_clkdm->clkdm_clear_all_wkdeps) + return -EINVAL; + + return arch_clkdm->clkdm_clear_all_wkdeps(clkdm); +} + +/** + * clkdm_add_sleepdep - add a sleep dependency from clkdm2 to clkdm1 + * @clkdm1: prevent this struct clockdomain * from sleeping (dependent) + * @clkdm2: when this struct clockdomain * is active (source) + * + * Prevent @clkdm1 from automatically going inactive (and then to + * retention or off) if @clkdm2 is active. Returns -EINVAL if + * presented with invalid clockdomain pointers or called on a machine + * that does not support software-configurable hardware sleep + * dependencies, -ENOENT if the specified dependency cannot be set in + * hardware, or 0 upon success. + */ +int clkdm_add_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2) +{ + struct clkdm_dep *cd; + int ret = 0; + + if (!clkdm1 || !clkdm2) + return -EINVAL; + + cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs); + if (IS_ERR(cd)) + ret = PTR_ERR(cd); + + if (!arch_clkdm || !arch_clkdm->clkdm_add_sleepdep) + ret = -EINVAL; + + if (ret) { + pr_debug("clockdomain: hardware cannot set/clear sleep " + "dependency affecting %s from %s\n", clkdm1->name, + clkdm2->name); + return ret; + } + + if (atomic_inc_return(&cd->sleepdep_usecount) == 1) { + pr_debug("clockdomain: will prevent %s from sleeping if %s " + "is active\n", clkdm1->name, clkdm2->name); + + ret = arch_clkdm->clkdm_add_sleepdep(clkdm1, clkdm2); + } + + return ret; +} + +/** + * clkdm_del_sleepdep - remove a sleep dependency from clkdm2 to clkdm1 + * @clkdm1: prevent this struct clockdomain * from sleeping (dependent) + * @clkdm2: when this struct clockdomain * is active (source) + * + * Allow @clkdm1 to automatically go inactive (and then to retention or + * off), independent of the activity state of @clkdm2. Returns -EINVAL + * if presented with invalid clockdomain pointers or called on a machine + * that does not support software-configurable hardware sleep dependencies, + * -ENOENT if the specified dependency cannot be cleared in hardware, or + * 0 upon success. + */ +int clkdm_del_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2) +{ + struct clkdm_dep *cd; + int ret = 0; + + if (!clkdm1 || !clkdm2) + return -EINVAL; + + cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs); + if (IS_ERR(cd)) + ret = PTR_ERR(cd); + + if (!arch_clkdm || !arch_clkdm->clkdm_del_sleepdep) + ret = -EINVAL; + + if (ret) { + pr_debug("clockdomain: hardware cannot set/clear sleep " + "dependency affecting %s from %s\n", clkdm1->name, + clkdm2->name); + return ret; + } + + if (atomic_dec_return(&cd->sleepdep_usecount) == 0) { + pr_debug("clockdomain: will no longer prevent %s from " + "sleeping if %s is active\n", clkdm1->name, + clkdm2->name); + + ret = arch_clkdm->clkdm_del_sleepdep(clkdm1, clkdm2); + } + + return ret; +} + +/** + * clkdm_read_sleepdep - read sleep dependency state from clkdm2 to clkdm1 + * @clkdm1: prevent this struct clockdomain * from sleeping (dependent) + * @clkdm2: when this struct clockdomain * is active (source) + * + * Return 1 if a hardware sleep dependency exists wherein @clkdm1 will + * not be allowed to automatically go inactive if @clkdm2 is active; + * 0 if @clkdm1's automatic power state inactivity transition is independent + * of @clkdm2's; -EINVAL if either clockdomain pointer is invalid or called + * on a machine that does not support software-configurable hardware sleep + * dependencies; or -ENOENT if the hardware is incapable. + * + * REVISIT: Currently this function only represents software-controllable + * sleep dependencies. Sleep dependencies fixed in hardware are not + * yet handled here. + */ +int clkdm_read_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2) +{ + struct clkdm_dep *cd; + int ret = 0; + + if (!clkdm1 || !clkdm2) + return -EINVAL; + + cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs); + if (IS_ERR(cd)) + ret = PTR_ERR(cd); + + if (!arch_clkdm || !arch_clkdm->clkdm_read_sleepdep) + ret = -EINVAL; + + if (ret) { + pr_debug("clockdomain: hardware cannot set/clear sleep " + "dependency affecting %s from %s\n", clkdm1->name, + clkdm2->name); + return ret; + } + + /* XXX It's faster to return the atomic sleepdep_usecount */ + return arch_clkdm->clkdm_read_sleepdep(clkdm1, clkdm2); +} + +/** + * clkdm_clear_all_sleepdeps - remove all sleep dependencies from target clkdm + * @clkdm: struct clockdomain * to remove all sleep dependencies from + * + * Remove all inter-clockdomain sleep dependencies that could prevent + * @clkdm from idling. Intended to be used during boot to initialize the + * PRCM to a known state, after all clockdomains are put into swsup idle + * and woken up. Returns -EINVAL if @clkdm pointer is invalid, or + * 0 upon success. + */ +int clkdm_clear_all_sleepdeps(struct clockdomain *clkdm) +{ + if (!clkdm) + return -EINVAL; + + if (!arch_clkdm || !arch_clkdm->clkdm_clear_all_sleepdeps) + return -EINVAL; + + return arch_clkdm->clkdm_clear_all_sleepdeps(clkdm); +} + +/** + * clkdm_sleep - force clockdomain sleep transition + * @clkdm: struct clockdomain * + * + * Instruct the CM to force a sleep transition on the specified + * clockdomain @clkdm. Returns -EINVAL if @clkdm is NULL or if + * clockdomain does not support software-initiated sleep; 0 upon + * success. + */ +int clkdm_sleep(struct clockdomain *clkdm) +{ + if (!clkdm) + return -EINVAL; + + if (!(clkdm->flags & CLKDM_CAN_FORCE_SLEEP)) { + pr_debug("clockdomain: %s does not support forcing " + "sleep via software\n", clkdm->name); + return -EINVAL; + } + + if (!arch_clkdm || !arch_clkdm->clkdm_sleep) + return -EINVAL; + + pr_debug("clockdomain: forcing sleep on %s\n", clkdm->name); + + return arch_clkdm->clkdm_sleep(clkdm); +} + +/** + * clkdm_wakeup - force clockdomain wakeup transition + * @clkdm: struct clockdomain * + * + * Instruct the CM to force a wakeup transition on the specified + * clockdomain @clkdm. Returns -EINVAL if @clkdm is NULL or if the + * clockdomain does not support software-controlled wakeup; 0 upon + * success. + */ +int clkdm_wakeup(struct clockdomain *clkdm) +{ + if (!clkdm) + return -EINVAL; + + if (!(clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)) { + pr_debug("clockdomain: %s does not support forcing " + "wakeup via software\n", clkdm->name); + return -EINVAL; + } + + if (!arch_clkdm || !arch_clkdm->clkdm_wakeup) + return -EINVAL; + + pr_debug("clockdomain: forcing wakeup on %s\n", clkdm->name); + + return arch_clkdm->clkdm_wakeup(clkdm); +} + +/** + * clkdm_allow_idle - enable hwsup idle transitions for clkdm + * @clkdm: struct clockdomain * + * + * Allow the hardware to automatically switch the clockdomain @clkdm into + * active or idle states, as needed by downstream clocks. If the + * clockdomain has any downstream clocks enabled in the clock + * framework, wkdep/sleepdep autodependencies are added; this is so + * device drivers can read and write to the device. No return value. + */ +void clkdm_allow_idle(struct clockdomain *clkdm) +{ + if (!clkdm) + return; + + if (!(clkdm->flags & CLKDM_CAN_ENABLE_AUTO)) { + pr_debug("clock: automatic idle transitions cannot be enabled " + "on clockdomain %s\n", clkdm->name); + return; + } + + if (!arch_clkdm || !arch_clkdm->clkdm_allow_idle) + return; + + pr_debug("clockdomain: enabling automatic idle transitions for %s\n", + clkdm->name); + + arch_clkdm->clkdm_allow_idle(clkdm); + pwrdm_clkdm_state_switch(clkdm); +} + +/** + * clkdm_deny_idle - disable hwsup idle transitions for clkdm + * @clkdm: struct clockdomain * + * + * Prevent the hardware from automatically switching the clockdomain + * @clkdm into inactive or idle states. If the clockdomain has + * downstream clocks enabled in the clock framework, wkdep/sleepdep + * autodependencies are removed. No return value. + */ +void clkdm_deny_idle(struct clockdomain *clkdm) +{ + if (!clkdm) + return; + + if (!(clkdm->flags & CLKDM_CAN_DISABLE_AUTO)) { + pr_debug("clockdomain: automatic idle transitions cannot be " + "disabled on %s\n", clkdm->name); + return; + } + + if (!arch_clkdm || !arch_clkdm->clkdm_deny_idle) + return; + + pr_debug("clockdomain: disabling automatic idle transitions for %s\n", + clkdm->name); + + arch_clkdm->clkdm_deny_idle(clkdm); +} + + +/* Clockdomain-to-clock framework interface code */ + +/** + * clkdm_clk_enable - add an enabled downstream clock to this clkdm + * @clkdm: struct clockdomain * + * @clk: struct clk * of the enabled downstream clock + * + * Increment the usecount of the clockdomain @clkdm and ensure that it + * is awake before @clk is enabled. Intended to be called by + * clk_enable() code. If the clockdomain is in software-supervised + * idle mode, force the clockdomain to wake. If the clockdomain is in + * hardware-supervised idle mode, add clkdm-pwrdm autodependencies, to + * ensure that devices in the clockdomain can be read from/written to + * by on-chip processors. Returns -EINVAL if passed null pointers; + * returns 0 upon success or if the clockdomain is in hwsup idle mode. + */ +int clkdm_clk_enable(struct clockdomain *clkdm, struct clk *clk) +{ + /* + * XXX Rewrite this code to maintain a list of enabled + * downstream clocks for debugging purposes? + */ + + if (!clkdm || !clk) + return -EINVAL; + + if (!arch_clkdm || !arch_clkdm->clkdm_clk_enable) + return -EINVAL; + + if (atomic_inc_return(&clkdm->usecount) > 1) + return 0; + + /* Clockdomain now has one enabled downstream clock */ + + pr_debug("clockdomain: clkdm %s: clk %s now enabled\n", clkdm->name, + clk->name); + + arch_clkdm->clkdm_clk_enable(clkdm); + pwrdm_wait_transition(clkdm->pwrdm.ptr); + pwrdm_clkdm_state_switch(clkdm); + + return 0; +} + +/** + * clkdm_clk_disable - remove an enabled downstream clock from this clkdm + * @clkdm: struct clockdomain * + * @clk: struct clk * of the disabled downstream clock + * + * Decrement the usecount of this clockdomain @clkdm when @clk is + * disabled. Intended to be called by clk_disable() code. If the + * clockdomain usecount goes to 0, put the clockdomain to sleep + * (software-supervised mode) or remove the clkdm autodependencies + * (hardware-supervised mode). Returns -EINVAL if passed null + * pointers; -ERANGE if the @clkdm usecount underflows and debugging + * is enabled; or returns 0 upon success or if the clockdomain is in + * hwsup idle mode. + */ +int clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk) +{ + /* + * XXX Rewrite this code to maintain a list of enabled + * downstream clocks for debugging purposes? + */ + + if (!clkdm || !clk) + return -EINVAL; + + if (!arch_clkdm || !arch_clkdm->clkdm_clk_disable) + return -EINVAL; + +#ifdef DEBUG + if (atomic_read(&clkdm->usecount) == 0) { + WARN_ON(1); /* underflow */ + return -ERANGE; + } +#endif + + if (atomic_dec_return(&clkdm->usecount) > 0) + return 0; + + /* All downstream clocks of this clockdomain are now disabled */ + + pr_debug("clockdomain: clkdm %s: clk %s now disabled\n", clkdm->name, + clk->name); + + arch_clkdm->clkdm_clk_disable(clkdm); + pwrdm_clkdm_state_switch(clkdm); + + return 0; +} + |