| /* |
| * OMAP2/3 clockdomain framework functions |
| * |
| * Copyright (C) 2008 Texas Instruments, Inc. |
| * Copyright (C) 2008 Nokia Corporation |
| * |
| * Written by Paul Walmsley and Jouni Högander |
| * |
| * 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. |
| */ |
| #ifdef CONFIG_OMAP_DEBUG_CLOCKDOMAIN |
| # define DEBUG |
| #endif |
| |
| #include <linux/module.h> |
| #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/io.h> |
| |
| #include <linux/bitops.h> |
| |
| #include <mach/clock.h> |
| |
| #include "prm.h" |
| #include "prm-regbits-24xx.h" |
| #include "cm.h" |
| |
| #include <mach/powerdomain.h> |
| #include <mach/clockdomain.h> |
| |
| /* clkdm_list contains all registered struct clockdomains */ |
| static LIST_HEAD(clkdm_list); |
| |
| /* clkdm_mutex protects clkdm_list add and del ops */ |
| static DEFINE_MUTEX(clkdm_mutex); |
| |
| /* array of powerdomain deps to be added/removed when clkdm in hwsup mode */ |
| static struct clkdm_pwrdm_autodep *autodeps; |
| |
| |
| /* Private functions */ |
| |
| /* |
| * _autodep_lookup - resolve autodep pwrdm names to pwrdm pointers; store |
| * @autodep: struct clkdm_pwrdm_autodep * to resolve |
| * |
| * Resolve autodep powerdomain names to powerdomain pointers via |
| * pwrdm_lookup() and store the pointers in the autodep structure. An |
| * "autodep" is a powerdomain 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. |
| */ |
| static void _autodep_lookup(struct clkdm_pwrdm_autodep *autodep) |
| { |
| struct powerdomain *pwrdm; |
| |
| if (!autodep) |
| return; |
| |
| if (!omap_chip_is(autodep->omap_chip)) |
| return; |
| |
| pwrdm = pwrdm_lookup(autodep->pwrdm_name); |
| if (!pwrdm) { |
| pr_debug("clockdomain: _autodep_lookup: powerdomain %s " |
| "does not exist\n", autodep->pwrdm_name); |
| WARN_ON(1); |
| return; |
| } |
| autodep->pwrdm = pwrdm; |
| |
| return; |
| } |
| |
| /* |
| * _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. |
| */ |
| static void _clkdm_add_autodeps(struct clockdomain *clkdm) |
| { |
| struct clkdm_pwrdm_autodep *autodep; |
| |
| for (autodep = autodeps; autodep->pwrdm_name; autodep++) { |
| if (!autodep->pwrdm) |
| continue; |
| |
| pr_debug("clockdomain: adding %s sleepdep/wkdep for " |
| "pwrdm %s\n", autodep->pwrdm_name, |
| clkdm->pwrdm->name); |
| |
| pwrdm_add_sleepdep(clkdm->pwrdm, autodep->pwrdm); |
| pwrdm_add_wkdep(clkdm->pwrdm, autodep->pwrdm); |
| } |
| } |
| |
| /* |
| * _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. |
| */ |
| static void _clkdm_del_autodeps(struct clockdomain *clkdm) |
| { |
| struct clkdm_pwrdm_autodep *autodep; |
| |
| for (autodep = autodeps; autodep->pwrdm_name; autodep++) { |
| if (!autodep->pwrdm) |
| continue; |
| |
| pr_debug("clockdomain: removing %s sleepdep/wkdep for " |
| "pwrdm %s\n", autodep->pwrdm_name, |
| clkdm->pwrdm->name); |
| |
| pwrdm_del_sleepdep(clkdm->pwrdm, autodep->pwrdm); |
| pwrdm_del_wkdep(clkdm->pwrdm, autodep->pwrdm); |
| } |
| } |
| |
| |
| 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; |
| } |
| |
| |
| /* 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 |
| * |
| * Set up internal state. If a pointer to an array of clockdomains |
| * 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-powerdomain autodependencies was |
| * provided, register those. No return value. |
| */ |
| void clkdm_init(struct clockdomain **clkdms, |
| struct clkdm_pwrdm_autodep *init_autodeps) |
| { |
| struct clockdomain **c = NULL; |
| struct clkdm_pwrdm_autodep *autodep = NULL; |
| |
| if (clkdms) |
| for (c = clkdms; *c; c++) |
| clkdm_register(*c); |
| |
| autodeps = init_autodeps; |
| if (autodeps) |
| for (autodep = autodeps; autodep->pwrdm_name; autodep++) |
| _autodep_lookup(autodep); |
| } |
| |
| /** |
| * 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. |
| */ |
| int clkdm_register(struct clockdomain *clkdm) |
| { |
| int ret = -EINVAL; |
| 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_debug("clockdomain: clkdm_register %s: powerdomain %s " |
| "does not exist\n", clkdm->name, clkdm->pwrdm_name); |
| return -EINVAL; |
| } |
| clkdm->pwrdm = pwrdm; |
| |
| mutex_lock(&clkdm_mutex); |
| /* Verify that the clockdomain is not already registered */ |
| if (_clkdm_lookup(clkdm->name)) { |
| ret = -EEXIST; |
| goto cr_unlock; |
| }; |
| |
| list_add(&clkdm->node, &clkdm_list); |
| |
| pr_debug("clockdomain: registered %s\n", clkdm->name); |
| ret = 0; |
| |
| cr_unlock: |
| mutex_unlock(&clkdm_mutex); |
| |
| return ret; |
| } |
| |
| /** |
| * clkdm_unregister - unregister a clockdomain |
| * @clkdm: struct clockdomain * to unregister |
| * |
| * Removes a clockdomain from the internal clockdomain list. Returns |
| * -EINVAL if clkdm argument is NULL. |
| */ |
| int clkdm_unregister(struct clockdomain *clkdm) |
| { |
| if (!clkdm) |
| return -EINVAL; |
| |
| mutex_lock(&clkdm_mutex); |
| list_del(&clkdm->node); |
| mutex_unlock(&clkdm_mutex); |
| |
| pr_debug("clockdomain: unregistered %s\n", clkdm->name); |
| |
| return 0; |
| } |
| |
| /** |
| * clkdm_lookup - look up a clockdomain by name, return a pointer |
| * @name: name of clockdomain |
| * |
| * Find a registered clockdomain by its 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; |
| |
| mutex_lock(&clkdm_mutex); |
| list_for_each_entry(temp_clkdm, &clkdm_list, node) { |
| if (!strcmp(name, temp_clkdm->name)) { |
| clkdm = temp_clkdm; |
| break; |
| } |
| } |
| mutex_unlock(&clkdm_mutex); |
| |
| return clkdm; |
| } |
| |
| /** |
| * clkdm_for_each - call function on each registered clockdomain |
| * @fn: callback function * |
| * |
| * Call the supplied function for each registered clockdomain. |
| * The callback function 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)) |
| { |
| struct clockdomain *clkdm; |
| int ret = 0; |
| |
| if (!fn) |
| return -EINVAL; |
| |
| mutex_lock(&clkdm_mutex); |
| list_for_each_entry(clkdm, &clkdm_list, node) { |
| ret = (*fn)(clkdm); |
| if (ret) |
| break; |
| } |
| mutex_unlock(&clkdm_mutex); |
| |
| return ret; |
| } |
| |
| |
| /* Hardware clockdomain control */ |
| |
| /** |
| * omap2_clkdm_clktrctrl_read - read the clkdm's current state transition mode |
| * @clk: struct clk * of a clockdomain |
| * |
| * Return the clockdomain's current state transition mode from the |
| * corresponding domain CM_CLKSTCTRL register. Returns -EINVAL if clk |
| * is NULL or the current mode upon success. |
| */ |
| static int omap2_clkdm_clktrctrl_read(struct clockdomain *clkdm) |
| { |
| u32 v; |
| |
| if (!clkdm) |
| return -EINVAL; |
| |
| v = cm_read_mod_reg(clkdm->pwrdm->prcm_offs, CM_CLKSTCTRL); |
| v &= clkdm->clktrctrl_mask; |
| v >>= __ffs(clkdm->clktrctrl_mask); |
| |
| return v; |
| } |
| |
| /** |
| * omap2_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 clk is NULL or if |
| * clockdomain does not support software-initiated sleep; 0 upon |
| * success. |
| */ |
| int omap2_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; |
| } |
| |
| pr_debug("clockdomain: forcing sleep on %s\n", clkdm->name); |
| |
| if (cpu_is_omap24xx()) { |
| |
| cm_set_mod_reg_bits(OMAP24XX_FORCESTATE, |
| clkdm->pwrdm->prcm_offs, PM_PWSTCTRL); |
| |
| } else if (cpu_is_omap34xx()) { |
| |
| u32 v = (OMAP34XX_CLKSTCTRL_FORCE_SLEEP << |
| __ffs(clkdm->clktrctrl_mask)); |
| |
| cm_rmw_mod_reg_bits(clkdm->clktrctrl_mask, v, |
| clkdm->pwrdm->prcm_offs, CM_CLKSTCTRL); |
| |
| } else { |
| BUG(); |
| }; |
| |
| return 0; |
| } |
| |
| /** |
| * omap2_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 omap2_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; |
| } |
| |
| pr_debug("clockdomain: forcing wakeup on %s\n", clkdm->name); |
| |
| if (cpu_is_omap24xx()) { |
| |
| cm_clear_mod_reg_bits(OMAP24XX_FORCESTATE, |
| clkdm->pwrdm->prcm_offs, PM_PWSTCTRL); |
| |
| } else if (cpu_is_omap34xx()) { |
| |
| u32 v = (OMAP34XX_CLKSTCTRL_FORCE_WAKEUP << |
| __ffs(clkdm->clktrctrl_mask)); |
| |
| cm_rmw_mod_reg_bits(clkdm->clktrctrl_mask, v, |
| clkdm->pwrdm->prcm_offs, CM_CLKSTCTRL); |
| |
| } else { |
| BUG(); |
| }; |
| |
| return 0; |
| } |
| |
| /** |
| * omap2_clkdm_allow_idle - enable hwsup idle transitions for clkdm |
| * @clkdm: struct clockdomain * |
| * |
| * Allow the hardware to automatically switch the clockdomain 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 omap2_clkdm_allow_idle(struct clockdomain *clkdm) |
| { |
| u32 v; |
| |
| 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; |
| } |
| |
| pr_debug("clockdomain: enabling automatic idle transitions for %s\n", |
| clkdm->name); |
| |
| if (atomic_read(&clkdm->usecount) > 0) |
| _clkdm_add_autodeps(clkdm); |
| |
| if (cpu_is_omap24xx()) |
| v = OMAP24XX_CLKSTCTRL_ENABLE_AUTO; |
| else if (cpu_is_omap34xx()) |
| v = OMAP34XX_CLKSTCTRL_ENABLE_AUTO; |
| else |
| BUG(); |
| |
| |
| cm_rmw_mod_reg_bits(clkdm->clktrctrl_mask, |
| v << __ffs(clkdm->clktrctrl_mask), |
| clkdm->pwrdm->prcm_offs, |
| CM_CLKSTCTRL); |
| } |
| |
| /** |
| * omap2_clkdm_deny_idle - disable hwsup idle transitions for clkdm |
| * @clkdm: struct clockdomain * |
| * |
| * Prevent the hardware from automatically switching the clockdomain |
| * 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 omap2_clkdm_deny_idle(struct clockdomain *clkdm) |
| { |
| u32 v; |
| |
| 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; |
| } |
| |
| pr_debug("clockdomain: disabling automatic idle transitions for %s\n", |
| clkdm->name); |
| |
| if (cpu_is_omap24xx()) |
| v = OMAP24XX_CLKSTCTRL_DISABLE_AUTO; |
| else if (cpu_is_omap34xx()) |
| v = OMAP34XX_CLKSTCTRL_DISABLE_AUTO; |
| else |
| BUG(); |
| |
| cm_rmw_mod_reg_bits(clkdm->clktrctrl_mask, |
| v << __ffs(clkdm->clktrctrl_mask), |
| clkdm->pwrdm->prcm_offs, CM_CLKSTCTRL); |
| |
| if (atomic_read(&clkdm->usecount) > 0) |
| _clkdm_del_autodeps(clkdm); |
| } |
| |
| |
| /* Clockdomain-to-clock framework interface code */ |
| |
| /** |
| * omap2_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 this clockdomain 'clkdm' and ensure that |
| * it is awake. 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 omap2_clkdm_clk_enable(struct clockdomain *clkdm, struct clk *clk) |
| { |
| int v; |
| |
| /* |
| * XXX Rewrite this code to maintain a list of enabled |
| * downstream clocks for debugging purposes? |
| */ |
| |
| if (!clkdm || !clk) |
| 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); |
| |
| v = omap2_clkdm_clktrctrl_read(clkdm); |
| |
| if ((cpu_is_omap34xx() && v == OMAP34XX_CLKSTCTRL_ENABLE_AUTO) || |
| (cpu_is_omap24xx() && v == OMAP24XX_CLKSTCTRL_ENABLE_AUTO)) |
| _clkdm_add_autodeps(clkdm); |
| else |
| omap2_clkdm_wakeup(clkdm); |
| |
| return 0; |
| } |
| |
| /** |
| * omap2_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'. Intended to be |
| * called by clk_disable() code. If the usecount goes to 0, put the |
| * clockdomain to sleep (software-supervised mode) or remove the |
| * clkdm-pwrdm 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 omap2_clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk) |
| { |
| int v; |
| |
| /* |
| * XXX Rewrite this code to maintain a list of enabled |
| * downstream clocks for debugging purposes? |
| */ |
| |
| if (!clkdm || !clk) |
| 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); |
| |
| v = omap2_clkdm_clktrctrl_read(clkdm); |
| |
| if ((cpu_is_omap34xx() && v == OMAP34XX_CLKSTCTRL_ENABLE_AUTO) || |
| (cpu_is_omap24xx() && v == OMAP24XX_CLKSTCTRL_ENABLE_AUTO)) |
| _clkdm_del_autodeps(clkdm); |
| else |
| omap2_clkdm_sleep(clkdm); |
| |
| return 0; |
| } |
| |