diff options
Diffstat (limited to 'arch/arm/plat-omap/omap_device.c')
| -rw-r--r-- | arch/arm/plat-omap/omap_device.c | 687 |
1 files changed, 687 insertions, 0 deletions
diff --git a/arch/arm/plat-omap/omap_device.c b/arch/arm/plat-omap/omap_device.c new file mode 100644 index 000000000000..2c409fc6dd21 --- /dev/null +++ b/arch/arm/plat-omap/omap_device.c @@ -0,0 +1,687 @@ +/* + * omap_device implementation + * + * Copyright (C) 2009 Nokia Corporation + * Paul Walmsley + * + * Developed 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 provides a consistent interface for OMAP device drivers + * to control power management and interconnect properties of their + * devices. + * + * In the medium- to long-term, this code should either be + * a) implemented via arch-specific pointers in platform_data + * or + * b) implemented as a proper omap_bus/omap_device in Linux, no more + * platform_data func pointers + * + * + * Guidelines for usage by driver authors: + * + * 1. These functions are intended to be used by device drivers via + * function pointers in struct platform_data. As an example, + * omap_device_enable() should be passed to the driver as + * + * struct foo_driver_platform_data { + * ... + * int (*device_enable)(struct platform_device *pdev); + * ... + * } + * + * Note that the generic "device_enable" name is used, rather than + * "omap_device_enable". This is so other architectures can pass in their + * own enable/disable functions here. + * + * This should be populated during device setup: + * + * ... + * pdata->device_enable = omap_device_enable; + * ... + * + * 2. Drivers should first check to ensure the function pointer is not null + * before calling it, as in: + * + * if (pdata->device_enable) + * pdata->device_enable(pdev); + * + * This allows other architectures that don't use similar device_enable()/ + * device_shutdown() functions to execute normally. + * + * ... + * + * Suggested usage by device drivers: + * + * During device initialization: + * device_enable() + * + * During device idle: + * (save remaining device context if necessary) + * device_idle(); + * + * During device resume: + * device_enable(); + * (restore context if necessary) + * + * During device shutdown: + * device_shutdown() + * (device must be reinitialized at this point to use it again) + * + */ +#undef DEBUG + +#include <linux/kernel.h> +#include <linux/platform_device.h> +#include <linux/err.h> +#include <linux/io.h> + +#include <mach/omap_device.h> +#include <mach/omap_hwmod.h> + +/* These parameters are passed to _omap_device_{de,}activate() */ +#define USE_WAKEUP_LAT 0 +#define IGNORE_WAKEUP_LAT 1 + +/* XXX this should be moved into a separate file */ +#if defined(CONFIG_ARCH_OMAP2420) +# define OMAP_32KSYNCT_BASE 0x48004000 +#elif defined(CONFIG_ARCH_OMAP2430) +# define OMAP_32KSYNCT_BASE 0x49020000 +#elif defined(CONFIG_ARCH_OMAP3430) +# define OMAP_32KSYNCT_BASE 0x48320000 +#else +# error Unknown OMAP device +#endif + +/* Private functions */ + +/** + * _read_32ksynct - read the OMAP 32K sync timer + * + * Returns the current value of the 32KiHz synchronization counter. + * XXX this should be generalized to simply read the system clocksource. + * XXX this should be moved to a separate synctimer32k.c file + */ +static u32 _read_32ksynct(void) +{ + if (!cpu_class_is_omap2()) + BUG(); + + return __raw_readl(OMAP2_IO_ADDRESS(OMAP_32KSYNCT_BASE + 0x010)); +} + +/** + * _omap_device_activate - increase device readiness + * @od: struct omap_device * + * @ignore_lat: increase to latency target (0) or full readiness (1)? + * + * Increase readiness of omap_device @od (thus decreasing device + * wakeup latency, but consuming more power). If @ignore_lat is + * IGNORE_WAKEUP_LAT, make the omap_device fully active. Otherwise, + * if @ignore_lat is USE_WAKEUP_LAT, and the device's maximum wakeup + * latency is greater than the requested maximum wakeup latency, step + * backwards in the omap_device_pm_latency table to ensure the + * device's maximum wakeup latency is less than or equal to the + * requested maximum wakeup latency. Returns 0. + */ +static int _omap_device_activate(struct omap_device *od, u8 ignore_lat) +{ + u32 a, b; + + pr_debug("omap_device: %s: activating\n", od->pdev.name); + + while (od->pm_lat_level > 0) { + struct omap_device_pm_latency *odpl; + int act_lat = 0; + + od->pm_lat_level--; + + odpl = od->pm_lats + od->pm_lat_level; + + if (!ignore_lat && + (od->dev_wakeup_lat <= od->_dev_wakeup_lat_limit)) + break; + + a = _read_32ksynct(); + + /* XXX check return code */ + odpl->activate_func(od); + + b = _read_32ksynct(); + + act_lat = (b - a) >> 15; /* 32KiHz cycles to microseconds */ + + pr_debug("omap_device: %s: pm_lat %d: activate: elapsed time " + "%d usec\n", od->pdev.name, od->pm_lat_level, act_lat); + + WARN(act_lat > odpl->activate_lat, "omap_device: %s.%d: " + "activate step %d took longer than expected (%d > %d)\n", + od->pdev.name, od->pdev.id, od->pm_lat_level, + act_lat, odpl->activate_lat); + + od->dev_wakeup_lat -= odpl->activate_lat; + } + + return 0; +} + +/** + * _omap_device_deactivate - decrease device readiness + * @od: struct omap_device * + * @ignore_lat: decrease to latency target (0) or full inactivity (1)? + * + * Decrease readiness of omap_device @od (thus increasing device + * wakeup latency, but conserving power). If @ignore_lat is + * IGNORE_WAKEUP_LAT, make the omap_device fully inactive. Otherwise, + * if @ignore_lat is USE_WAKEUP_LAT, and the device's maximum wakeup + * latency is less than the requested maximum wakeup latency, step + * forwards in the omap_device_pm_latency table to ensure the device's + * maximum wakeup latency is less than or equal to the requested + * maximum wakeup latency. Returns 0. + */ +static int _omap_device_deactivate(struct omap_device *od, u8 ignore_lat) +{ + u32 a, b; + + pr_debug("omap_device: %s: deactivating\n", od->pdev.name); + + while (od->pm_lat_level < od->pm_lats_cnt) { + struct omap_device_pm_latency *odpl; + int deact_lat = 0; + + odpl = od->pm_lats + od->pm_lat_level; + + if (!ignore_lat && + ((od->dev_wakeup_lat + odpl->activate_lat) > + od->_dev_wakeup_lat_limit)) + break; + + a = _read_32ksynct(); + + /* XXX check return code */ + odpl->deactivate_func(od); + + b = _read_32ksynct(); + + deact_lat = (b - a) >> 15; /* 32KiHz cycles to microseconds */ + + pr_debug("omap_device: %s: pm_lat %d: deactivate: elapsed time " + "%d usec\n", od->pdev.name, od->pm_lat_level, + deact_lat); + + WARN(deact_lat > odpl->deactivate_lat, "omap_device: %s.%d: " + "deactivate step %d took longer than expected (%d > %d)\n", + od->pdev.name, od->pdev.id, od->pm_lat_level, + deact_lat, odpl->deactivate_lat); + + od->dev_wakeup_lat += odpl->activate_lat; + + od->pm_lat_level++; + } + + return 0; +} + +static inline struct omap_device *_find_by_pdev(struct platform_device *pdev) +{ + return container_of(pdev, struct omap_device, pdev); +} + + +/* Public functions for use by core code */ + +/** + * omap_device_count_resources - count number of struct resource entries needed + * @od: struct omap_device * + * + * Count the number of struct resource entries needed for this + * omap_device @od. Used by omap_device_build_ss() to determine how + * much memory to allocate before calling + * omap_device_fill_resources(). Returns the count. + */ +int omap_device_count_resources(struct omap_device *od) +{ + struct omap_hwmod *oh; + int c = 0; + int i; + + for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++) + c += omap_hwmod_count_resources(oh); + + pr_debug("omap_device: %s: counted %d total resources across %d " + "hwmods\n", od->pdev.name, c, od->hwmods_cnt); + + return c; +} + +/** + * omap_device_fill_resources - fill in array of struct resource + * @od: struct omap_device * + * @res: pointer to an array of struct resource to be filled in + * + * Populate one or more empty struct resource pointed to by @res with + * the resource data for this omap_device @od. Used by + * omap_device_build_ss() after calling omap_device_count_resources(). + * Ideally this function would not be needed at all. If omap_device + * replaces platform_device, then we can specify our own + * get_resource()/ get_irq()/etc functions that use the underlying + * omap_hwmod information. Or if platform_device is extended to use + * subarchitecture-specific function pointers, the various + * platform_device functions can simply call omap_device internal + * functions to get device resources. Hacking around the existing + * platform_device code wastes memory. Returns 0. + */ +int omap_device_fill_resources(struct omap_device *od, struct resource *res) +{ + struct omap_hwmod *oh; + int c = 0; + int i, r; + + for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++) { + r = omap_hwmod_fill_resources(oh, res); + res += r; + c += r; + } + + return 0; +} + +/** + * omap_device_build - build and register an omap_device with one omap_hwmod + * @pdev_name: name of the platform_device driver to use + * @pdev_id: this platform_device's connection ID + * @oh: ptr to the single omap_hwmod that backs this omap_device + * @pdata: platform_data ptr to associate with the platform_device + * @pdata_len: amount of memory pointed to by @pdata + * @pm_lats: pointer to a omap_device_pm_latency array for this device + * @pm_lats_cnt: ARRAY_SIZE() of @pm_lats + * + * Convenience function for building and registering a single + * omap_device record, which in turn builds and registers a + * platform_device record. See omap_device_build_ss() for more + * information. Returns ERR_PTR(-EINVAL) if @oh is NULL; otherwise, + * passes along the return value of omap_device_build_ss(). + */ +struct omap_device *omap_device_build(const char *pdev_name, int pdev_id, + struct omap_hwmod *oh, void *pdata, + int pdata_len, + struct omap_device_pm_latency *pm_lats, + int pm_lats_cnt) +{ + struct omap_hwmod *ohs[] = { oh }; + + if (!oh) + return ERR_PTR(-EINVAL); + + return omap_device_build_ss(pdev_name, pdev_id, ohs, 1, pdata, + pdata_len, pm_lats, pm_lats_cnt); +} + +/** + * omap_device_build_ss - build and register an omap_device with multiple hwmods + * @pdev_name: name of the platform_device driver to use + * @pdev_id: this platform_device's connection ID + * @oh: ptr to the single omap_hwmod that backs this omap_device + * @pdata: platform_data ptr to associate with the platform_device + * @pdata_len: amount of memory pointed to by @pdata + * @pm_lats: pointer to a omap_device_pm_latency array for this device + * @pm_lats_cnt: ARRAY_SIZE() of @pm_lats + * + * Convenience function for building and registering an omap_device + * subsystem record. Subsystem records consist of multiple + * omap_hwmods. This function in turn builds and registers a + * platform_device record. Returns an ERR_PTR() on error, or passes + * along the return value of omap_device_register(). + */ +struct omap_device *omap_device_build_ss(const char *pdev_name, int pdev_id, + struct omap_hwmod **ohs, int oh_cnt, + void *pdata, int pdata_len, + struct omap_device_pm_latency *pm_lats, + int pm_lats_cnt) +{ + int ret = -ENOMEM; + struct omap_device *od; + char *pdev_name2; + struct resource *res = NULL; + int res_count; + struct omap_hwmod **hwmods; + + if (!ohs || oh_cnt == 0 || !pdev_name) + return ERR_PTR(-EINVAL); + + if (!pdata && pdata_len > 0) + return ERR_PTR(-EINVAL); + + pr_debug("omap_device: %s: building with %d hwmods\n", pdev_name, + oh_cnt); + + od = kzalloc(sizeof(struct omap_device), GFP_KERNEL); + if (!od) + return ERR_PTR(-ENOMEM); + + od->hwmods_cnt = oh_cnt; + + hwmods = kzalloc(sizeof(struct omap_hwmod *) * oh_cnt, + GFP_KERNEL); + if (!hwmods) + goto odbs_exit1; + + memcpy(hwmods, ohs, sizeof(struct omap_hwmod *) * oh_cnt); + od->hwmods = hwmods; + + pdev_name2 = kzalloc(strlen(pdev_name) + 1, GFP_KERNEL); + if (!pdev_name2) + goto odbs_exit2; + strcpy(pdev_name2, pdev_name); + + od->pdev.name = pdev_name2; + od->pdev.id = pdev_id; + + res_count = omap_device_count_resources(od); + if (res_count > 0) { + res = kzalloc(sizeof(struct resource) * res_count, GFP_KERNEL); + if (!res) + goto odbs_exit3; + } + omap_device_fill_resources(od, res); + + od->pdev.num_resources = res_count; + od->pdev.resource = res; + + platform_device_add_data(&od->pdev, pdata, pdata_len); + + od->pm_lats = pm_lats; + od->pm_lats_cnt = pm_lats_cnt; + + ret = omap_device_register(od); + if (ret) + goto odbs_exit4; + + return od; + +odbs_exit4: + kfree(res); +odbs_exit3: + kfree(pdev_name2); +odbs_exit2: + kfree(hwmods); +odbs_exit1: + kfree(od); + + pr_err("omap_device: %s: build failed (%d)\n", pdev_name, ret); + + return ERR_PTR(ret); +} + +/** + * omap_device_register - register an omap_device with one omap_hwmod + * @od: struct omap_device * to register + * + * Register the omap_device structure. This currently just calls + * platform_device_register() on the underlying platform_device. + * Returns the return value of platform_device_register(). + */ +int omap_device_register(struct omap_device *od) +{ + pr_debug("omap_device: %s: registering\n", od->pdev.name); + + return platform_device_register(&od->pdev); +} + + +/* Public functions for use by device drivers through struct platform_data */ + +/** + * omap_device_enable - fully activate an omap_device + * @od: struct omap_device * to activate + * + * Do whatever is necessary for the hwmods underlying omap_device @od + * to be accessible and ready to operate. This generally involves + * enabling clocks, setting SYSCONFIG registers; and in the future may + * involve remuxing pins. Device drivers should call this function + * (through platform_data function pointers) where they would normally + * enable clocks, etc. Returns -EINVAL if called when the omap_device + * is already enabled, or passes along the return value of + * _omap_device_activate(). + */ +int omap_device_enable(struct platform_device *pdev) +{ + int ret; + struct omap_device *od; + + od = _find_by_pdev(pdev); + + if (od->_state == OMAP_DEVICE_STATE_ENABLED) { + WARN(1, "omap_device: %s.%d: omap_device_enable() called from " + "invalid state\n", od->pdev.name, od->pdev.id); + return -EINVAL; + } + + /* Enable everything if we're enabling this device from scratch */ + if (od->_state == OMAP_DEVICE_STATE_UNKNOWN) + od->pm_lat_level = od->pm_lats_cnt; + + ret = _omap_device_activate(od, IGNORE_WAKEUP_LAT); + + od->dev_wakeup_lat = 0; + od->_dev_wakeup_lat_limit = INT_MAX; + od->_state = OMAP_DEVICE_STATE_ENABLED; + + return ret; +} + +/** + * omap_device_idle - idle an omap_device + * @od: struct omap_device * to idle + * + * Idle omap_device @od by calling as many .deactivate_func() entries + * in the omap_device's pm_lats table as is possible without exceeding + * the device's maximum wakeup latency limit, pm_lat_limit. Device + * drivers should call this function (through platform_data function + * pointers) where they would normally disable clocks after operations + * complete, etc.. Returns -EINVAL if the omap_device is not + * currently enabled, or passes along the return value of + * _omap_device_deactivate(). + */ +int omap_device_idle(struct platform_device *pdev) +{ + int ret; + struct omap_device *od; + + od = _find_by_pdev(pdev); + + if (od->_state != OMAP_DEVICE_STATE_ENABLED) { + WARN(1, "omap_device: %s.%d: omap_device_idle() called from " + "invalid state\n", od->pdev.name, od->pdev.id); + return -EINVAL; + } + + ret = _omap_device_deactivate(od, USE_WAKEUP_LAT); + + od->_state = OMAP_DEVICE_STATE_IDLE; + + return ret; +} + +/** + * omap_device_shutdown - shut down an omap_device + * @od: struct omap_device * to shut down + * + * Shut down omap_device @od by calling all .deactivate_func() entries + * in the omap_device's pm_lats table and then shutting down all of + * the underlying omap_hwmods. Used when a device is being "removed" + * or a device driver is being unloaded. Returns -EINVAL if the + * omap_device is not currently enabled or idle, or passes along the + * return value of _omap_device_deactivate(). + */ +int omap_device_shutdown(struct platform_device *pdev) +{ + int ret, i; + struct omap_device *od; + struct omap_hwmod *oh; + + od = _find_by_pdev(pdev); + + if (od->_state != OMAP_DEVICE_STATE_ENABLED && + od->_state != OMAP_DEVICE_STATE_IDLE) { + WARN(1, "omap_device: %s.%d: omap_device_shutdown() called " + "from invalid state\n", od->pdev.name, od->pdev.id); + return -EINVAL; + } + + ret = _omap_device_deactivate(od, IGNORE_WAKEUP_LAT); + + for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++) + omap_hwmod_shutdown(oh); + + od->_state = OMAP_DEVICE_STATE_SHUTDOWN; + + return ret; +} + +/** + * omap_device_align_pm_lat - activate/deactivate device to match wakeup lat lim + * @od: struct omap_device * + * + * When a device's maximum wakeup latency limit changes, call some of + * the .activate_func or .deactivate_func function pointers in the + * omap_device's pm_lats array to ensure that the device's maximum + * wakeup latency is less than or equal to the new latency limit. + * Intended to be called by OMAP PM code whenever a device's maximum + * wakeup latency limit changes (e.g., via + * omap_pm_set_dev_wakeup_lat()). Returns 0 if nothing needs to be + * done (e.g., if the omap_device is not currently idle, or if the + * wakeup latency is already current with the new limit) or passes + * along the return value of _omap_device_deactivate() or + * _omap_device_activate(). + */ +int omap_device_align_pm_lat(struct platform_device *pdev, + u32 new_wakeup_lat_limit) +{ + int ret = -EINVAL; + struct omap_device *od; + + od = _find_by_pdev(pdev); + + if (new_wakeup_lat_limit == od->dev_wakeup_lat) + return 0; + + od->_dev_wakeup_lat_limit = new_wakeup_lat_limit; + + if (od->_state != OMAP_DEVICE_STATE_IDLE) + return 0; + else if (new_wakeup_lat_limit > od->dev_wakeup_lat) + ret = _omap_device_deactivate(od, USE_WAKEUP_LAT); + else if (new_wakeup_lat_limit < od->dev_wakeup_lat) + ret = _omap_device_activate(od, USE_WAKEUP_LAT); + + return ret; +} + +/** + * omap_device_get_pwrdm - return the powerdomain * associated with @od + * @od: struct omap_device * + * + * Return the powerdomain associated with the first underlying + * omap_hwmod for this omap_device. Intended for use by core OMAP PM + * code. Returns NULL on error or a struct powerdomain * upon + * success. + */ +struct powerdomain *omap_device_get_pwrdm(struct omap_device *od) +{ + /* + * XXX Assumes that all omap_hwmod powerdomains are identical. + * This may not necessarily be true. There should be a sanity + * check in here to WARN() if any difference appears. + */ + if (!od->hwmods_cnt) + return NULL; + + return omap_hwmod_get_pwrdm(od->hwmods[0]); +} + +/* + * Public functions intended for use in omap_device_pm_latency + * .activate_func and .deactivate_func function pointers + */ + +/** + * omap_device_enable_hwmods - call omap_hwmod_enable() on all hwmods + * @od: struct omap_device *od + * + * Enable all underlying hwmods. Returns 0. + */ +int omap_device_enable_hwmods(struct omap_device *od) +{ + struct omap_hwmod *oh; + int i; + + for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++) + omap_hwmod_enable(oh); + + /* XXX pass along return value here? */ + return 0; +} + +/** + * omap_device_idle_hwmods - call omap_hwmod_idle() on all hwmods + * @od: struct omap_device *od + * + * Idle all underlying hwmods. Returns 0. + */ +int omap_device_idle_hwmods(struct omap_device *od) +{ + struct omap_hwmod *oh; + int i; + + for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++) + omap_hwmod_idle(oh); + + /* XXX pass along return value here? */ + return 0; +} + +/** + * omap_device_disable_clocks - disable all main and interface clocks + * @od: struct omap_device *od + * + * Disable the main functional clock and interface clock for all of the + * omap_hwmods associated with the omap_device. Returns 0. + */ +int omap_device_disable_clocks(struct omap_device *od) +{ + struct omap_hwmod *oh; + int i; + + for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++) + omap_hwmod_disable_clocks(oh); + + /* XXX pass along return value here? */ + return 0; +} + +/** + * omap_device_enable_clocks - enable all main and interface clocks + * @od: struct omap_device *od + * + * Enable the main functional clock and interface clock for all of the + * omap_hwmods associated with the omap_device. Returns 0. + */ +int omap_device_enable_clocks(struct omap_device *od) +{ + struct omap_hwmod *oh; + int i; + + for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++) + omap_hwmod_enable_clocks(oh); + + /* XXX pass along return value here? */ + return 0; +} |