2 * omap_device implementation
4 * Copyright (C) 2009 Nokia Corporation
7 * Developed in collaboration with (alphabetical order): Benoit
8 * Cousson, Kevin Hilman, Tony Lindgren, Rajendra Nayak, Vikram
9 * Pandita, Sakari Poussa, Anand Sawant, Santosh Shilimkar, Richard
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
16 * This code provides a consistent interface for OMAP device drivers
17 * to control power management and interconnect properties of their
20 * In the medium- to long-term, this code should either be
21 * a) implemented via arch-specific pointers in platform_data
23 * b) implemented as a proper omap_bus/omap_device in Linux, no more
24 * platform_data func pointers
27 * Guidelines for usage by driver authors:
29 * 1. These functions are intended to be used by device drivers via
30 * function pointers in struct platform_data. As an example,
31 * omap_device_enable() should be passed to the driver as
33 * struct foo_driver_platform_data {
35 * int (*device_enable)(struct platform_device *pdev);
39 * Note that the generic "device_enable" name is used, rather than
40 * "omap_device_enable". This is so other architectures can pass in their
41 * own enable/disable functions here.
43 * This should be populated during device setup:
46 * pdata->device_enable = omap_device_enable;
49 * 2. Drivers should first check to ensure the function pointer is not null
50 * before calling it, as in:
52 * if (pdata->device_enable)
53 * pdata->device_enable(pdev);
55 * This allows other architectures that don't use similar device_enable()/
56 * device_shutdown() functions to execute normally.
60 * Suggested usage by device drivers:
62 * During device initialization:
66 * (save remaining device context if necessary)
69 * During device resume:
71 * (restore context if necessary)
73 * During device shutdown:
75 * (device must be reinitialized at this point to use it again)
80 #include <linux/kernel.h>
81 #include <linux/platform_device.h>
82 #include <linux/err.h>
85 #include <plat/omap_device.h>
86 #include <plat/omap_hwmod.h>
88 /* These parameters are passed to _omap_device_{de,}activate() */
89 #define USE_WAKEUP_LAT 0
90 #define IGNORE_WAKEUP_LAT 1
93 #define OMAP_DEVICE_MAGIC 0xf00dcafe
95 /* Private functions */
98 * _omap_device_activate - increase device readiness
99 * @od: struct omap_device *
100 * @ignore_lat: increase to latency target (0) or full readiness (1)?
102 * Increase readiness of omap_device @od (thus decreasing device
103 * wakeup latency, but consuming more power). If @ignore_lat is
104 * IGNORE_WAKEUP_LAT, make the omap_device fully active. Otherwise,
105 * if @ignore_lat is USE_WAKEUP_LAT, and the device's maximum wakeup
106 * latency is greater than the requested maximum wakeup latency, step
107 * backwards in the omap_device_pm_latency table to ensure the
108 * device's maximum wakeup latency is less than or equal to the
109 * requested maximum wakeup latency. Returns 0.
111 static int _omap_device_activate(struct omap_device *od, u8 ignore_lat)
113 struct timespec a, b, c;
115 pr_debug("omap_device: %s: activating\n", od->pdev.name);
117 while (od->pm_lat_level > 0) {
118 struct omap_device_pm_latency *odpl;
119 unsigned long long act_lat = 0;
123 odpl = od->pm_lats + od->pm_lat_level;
126 (od->dev_wakeup_lat <= od->_dev_wakeup_lat_limit))
129 read_persistent_clock(&a);
131 /* XXX check return code */
132 odpl->activate_func(od);
134 read_persistent_clock(&b);
136 c = timespec_sub(b, a);
137 act_lat = timespec_to_ns(&c);
139 pr_debug("omap_device: %s: pm_lat %d: activate: elapsed time "
140 "%llu nsec\n", od->pdev.name, od->pm_lat_level,
143 if (act_lat > odpl->activate_lat) {
144 odpl->activate_lat_worst = act_lat;
145 if (odpl->flags & OMAP_DEVICE_LATENCY_AUTO_ADJUST) {
146 odpl->activate_lat = act_lat;
147 pr_warning("omap_device: %s.%d: new worst case "
148 "activate latency %d: %llu\n",
149 od->pdev.name, od->pdev.id,
150 od->pm_lat_level, act_lat);
152 pr_warning("omap_device: %s.%d: activate "
153 "latency %d higher than exptected. "
155 od->pdev.name, od->pdev.id,
156 od->pm_lat_level, act_lat,
160 od->dev_wakeup_lat -= odpl->activate_lat;
167 * _omap_device_deactivate - decrease device readiness
168 * @od: struct omap_device *
169 * @ignore_lat: decrease to latency target (0) or full inactivity (1)?
171 * Decrease readiness of omap_device @od (thus increasing device
172 * wakeup latency, but conserving power). If @ignore_lat is
173 * IGNORE_WAKEUP_LAT, make the omap_device fully inactive. Otherwise,
174 * if @ignore_lat is USE_WAKEUP_LAT, and the device's maximum wakeup
175 * latency is less than the requested maximum wakeup latency, step
176 * forwards in the omap_device_pm_latency table to ensure the device's
177 * maximum wakeup latency is less than or equal to the requested
178 * maximum wakeup latency. Returns 0.
180 static int _omap_device_deactivate(struct omap_device *od, u8 ignore_lat)
182 struct timespec a, b, c;
184 pr_debug("omap_device: %s: deactivating\n", od->pdev.name);
186 while (od->pm_lat_level < od->pm_lats_cnt) {
187 struct omap_device_pm_latency *odpl;
188 unsigned long long deact_lat = 0;
190 odpl = od->pm_lats + od->pm_lat_level;
193 ((od->dev_wakeup_lat + odpl->activate_lat) >
194 od->_dev_wakeup_lat_limit))
197 read_persistent_clock(&a);
199 /* XXX check return code */
200 odpl->deactivate_func(od);
202 read_persistent_clock(&b);
204 c = timespec_sub(b, a);
205 deact_lat = timespec_to_ns(&c);
207 pr_debug("omap_device: %s: pm_lat %d: deactivate: elapsed time "
208 "%llu nsec\n", od->pdev.name, od->pm_lat_level,
211 if (deact_lat > odpl->deactivate_lat) {
212 odpl->deactivate_lat_worst = deact_lat;
213 if (odpl->flags & OMAP_DEVICE_LATENCY_AUTO_ADJUST) {
214 odpl->deactivate_lat = deact_lat;
215 pr_warning("omap_device: %s.%d: new worst case "
216 "deactivate latency %d: %llu\n",
217 od->pdev.name, od->pdev.id,
218 od->pm_lat_level, deact_lat);
220 pr_warning("omap_device: %s.%d: deactivate "
221 "latency %d higher than exptected. "
223 od->pdev.name, od->pdev.id,
224 od->pm_lat_level, deact_lat,
225 odpl->deactivate_lat);
229 od->dev_wakeup_lat += odpl->activate_lat;
237 static inline struct omap_device *_find_by_pdev(struct platform_device *pdev)
239 return container_of(pdev, struct omap_device, pdev);
243 /* Public functions for use by core code */
246 * omap_device_count_resources - count number of struct resource entries needed
247 * @od: struct omap_device *
249 * Count the number of struct resource entries needed for this
250 * omap_device @od. Used by omap_device_build_ss() to determine how
251 * much memory to allocate before calling
252 * omap_device_fill_resources(). Returns the count.
254 int omap_device_count_resources(struct omap_device *od)
256 struct omap_hwmod *oh;
260 for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++)
261 c += omap_hwmod_count_resources(oh);
263 pr_debug("omap_device: %s: counted %d total resources across %d "
264 "hwmods\n", od->pdev.name, c, od->hwmods_cnt);
270 * omap_device_fill_resources - fill in array of struct resource
271 * @od: struct omap_device *
272 * @res: pointer to an array of struct resource to be filled in
274 * Populate one or more empty struct resource pointed to by @res with
275 * the resource data for this omap_device @od. Used by
276 * omap_device_build_ss() after calling omap_device_count_resources().
277 * Ideally this function would not be needed at all. If omap_device
278 * replaces platform_device, then we can specify our own
279 * get_resource()/ get_irq()/etc functions that use the underlying
280 * omap_hwmod information. Or if platform_device is extended to use
281 * subarchitecture-specific function pointers, the various
282 * platform_device functions can simply call omap_device internal
283 * functions to get device resources. Hacking around the existing
284 * platform_device code wastes memory. Returns 0.
286 int omap_device_fill_resources(struct omap_device *od, struct resource *res)
288 struct omap_hwmod *oh;
292 for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++) {
293 r = omap_hwmod_fill_resources(oh, res);
302 * omap_device_build - build and register an omap_device with one omap_hwmod
303 * @pdev_name: name of the platform_device driver to use
304 * @pdev_id: this platform_device's connection ID
305 * @oh: ptr to the single omap_hwmod that backs this omap_device
306 * @pdata: platform_data ptr to associate with the platform_device
307 * @pdata_len: amount of memory pointed to by @pdata
308 * @pm_lats: pointer to a omap_device_pm_latency array for this device
309 * @pm_lats_cnt: ARRAY_SIZE() of @pm_lats
311 * Convenience function for building and registering a single
312 * omap_device record, which in turn builds and registers a
313 * platform_device record. See omap_device_build_ss() for more
314 * information. Returns ERR_PTR(-EINVAL) if @oh is NULL; otherwise,
315 * passes along the return value of omap_device_build_ss().
317 struct omap_device *omap_device_build(const char *pdev_name, int pdev_id,
318 struct omap_hwmod *oh, void *pdata,
320 struct omap_device_pm_latency *pm_lats,
323 struct omap_hwmod *ohs[] = { oh };
326 return ERR_PTR(-EINVAL);
328 return omap_device_build_ss(pdev_name, pdev_id, ohs, 1, pdata,
329 pdata_len, pm_lats, pm_lats_cnt);
333 * omap_device_build_ss - build and register an omap_device with multiple hwmods
334 * @pdev_name: name of the platform_device driver to use
335 * @pdev_id: this platform_device's connection ID
336 * @oh: ptr to the single omap_hwmod that backs this omap_device
337 * @pdata: platform_data ptr to associate with the platform_device
338 * @pdata_len: amount of memory pointed to by @pdata
339 * @pm_lats: pointer to a omap_device_pm_latency array for this device
340 * @pm_lats_cnt: ARRAY_SIZE() of @pm_lats
342 * Convenience function for building and registering an omap_device
343 * subsystem record. Subsystem records consist of multiple
344 * omap_hwmods. This function in turn builds and registers a
345 * platform_device record. Returns an ERR_PTR() on error, or passes
346 * along the return value of omap_device_register().
348 struct omap_device *omap_device_build_ss(const char *pdev_name, int pdev_id,
349 struct omap_hwmod **ohs, int oh_cnt,
350 void *pdata, int pdata_len,
351 struct omap_device_pm_latency *pm_lats,
355 struct omap_device *od;
357 struct resource *res = NULL;
359 struct omap_hwmod **hwmods;
361 if (!ohs || oh_cnt == 0 || !pdev_name)
362 return ERR_PTR(-EINVAL);
364 if (!pdata && pdata_len > 0)
365 return ERR_PTR(-EINVAL);
367 pr_debug("omap_device: %s: building with %d hwmods\n", pdev_name,
370 od = kzalloc(sizeof(struct omap_device), GFP_KERNEL);
372 return ERR_PTR(-ENOMEM);
374 od->hwmods_cnt = oh_cnt;
376 hwmods = kzalloc(sizeof(struct omap_hwmod *) * oh_cnt,
381 memcpy(hwmods, ohs, sizeof(struct omap_hwmod *) * oh_cnt);
384 pdev_name2 = kzalloc(strlen(pdev_name) + 1, GFP_KERNEL);
387 strcpy(pdev_name2, pdev_name);
389 od->pdev.name = pdev_name2;
390 od->pdev.id = pdev_id;
392 res_count = omap_device_count_resources(od);
394 res = kzalloc(sizeof(struct resource) * res_count, GFP_KERNEL);
398 omap_device_fill_resources(od, res);
400 od->pdev.num_resources = res_count;
401 od->pdev.resource = res;
403 platform_device_add_data(&od->pdev, pdata, pdata_len);
405 od->pm_lats = pm_lats;
406 od->pm_lats_cnt = pm_lats_cnt;
408 od->magic = OMAP_DEVICE_MAGIC;
410 ret = omap_device_register(od);
425 pr_err("omap_device: %s: build failed (%d)\n", pdev_name, ret);
431 * omap_device_register - register an omap_device with one omap_hwmod
432 * @od: struct omap_device * to register
434 * Register the omap_device structure. This currently just calls
435 * platform_device_register() on the underlying platform_device.
436 * Returns the return value of platform_device_register().
438 int omap_device_register(struct omap_device *od)
440 pr_debug("omap_device: %s: registering\n", od->pdev.name);
442 return platform_device_register(&od->pdev);
446 /* Public functions for use by device drivers through struct platform_data */
449 * omap_device_enable - fully activate an omap_device
450 * @od: struct omap_device * to activate
452 * Do whatever is necessary for the hwmods underlying omap_device @od
453 * to be accessible and ready to operate. This generally involves
454 * enabling clocks, setting SYSCONFIG registers; and in the future may
455 * involve remuxing pins. Device drivers should call this function
456 * (through platform_data function pointers) where they would normally
457 * enable clocks, etc. Returns -EINVAL if called when the omap_device
458 * is already enabled, or passes along the return value of
459 * _omap_device_activate().
461 int omap_device_enable(struct platform_device *pdev)
464 struct omap_device *od;
466 od = _find_by_pdev(pdev);
468 if (od->_state == OMAP_DEVICE_STATE_ENABLED) {
469 WARN(1, "omap_device: %s.%d: %s() called from invalid state %d\n",
470 od->pdev.name, od->pdev.id, __func__, od->_state);
474 /* Enable everything if we're enabling this device from scratch */
475 if (od->_state == OMAP_DEVICE_STATE_UNKNOWN)
476 od->pm_lat_level = od->pm_lats_cnt;
478 ret = _omap_device_activate(od, IGNORE_WAKEUP_LAT);
480 od->dev_wakeup_lat = 0;
481 od->_dev_wakeup_lat_limit = UINT_MAX;
482 od->_state = OMAP_DEVICE_STATE_ENABLED;
488 * omap_device_idle - idle an omap_device
489 * @od: struct omap_device * to idle
491 * Idle omap_device @od by calling as many .deactivate_func() entries
492 * in the omap_device's pm_lats table as is possible without exceeding
493 * the device's maximum wakeup latency limit, pm_lat_limit. Device
494 * drivers should call this function (through platform_data function
495 * pointers) where they would normally disable clocks after operations
496 * complete, etc.. Returns -EINVAL if the omap_device is not
497 * currently enabled, or passes along the return value of
498 * _omap_device_deactivate().
500 int omap_device_idle(struct platform_device *pdev)
503 struct omap_device *od;
505 od = _find_by_pdev(pdev);
507 if (od->_state != OMAP_DEVICE_STATE_ENABLED) {
508 WARN(1, "omap_device: %s.%d: %s() called from invalid state %d\n",
509 od->pdev.name, od->pdev.id, __func__, od->_state);
513 ret = _omap_device_deactivate(od, USE_WAKEUP_LAT);
515 od->_state = OMAP_DEVICE_STATE_IDLE;
521 * omap_device_shutdown - shut down an omap_device
522 * @od: struct omap_device * to shut down
524 * Shut down omap_device @od by calling all .deactivate_func() entries
525 * in the omap_device's pm_lats table and then shutting down all of
526 * the underlying omap_hwmods. Used when a device is being "removed"
527 * or a device driver is being unloaded. Returns -EINVAL if the
528 * omap_device is not currently enabled or idle, or passes along the
529 * return value of _omap_device_deactivate().
531 int omap_device_shutdown(struct platform_device *pdev)
534 struct omap_device *od;
535 struct omap_hwmod *oh;
537 od = _find_by_pdev(pdev);
539 if (od->_state != OMAP_DEVICE_STATE_ENABLED &&
540 od->_state != OMAP_DEVICE_STATE_IDLE) {
541 WARN(1, "omap_device: %s.%d: %s() called from invalid state %d\n",
542 od->pdev.name, od->pdev.id, __func__, od->_state);
546 ret = _omap_device_deactivate(od, IGNORE_WAKEUP_LAT);
548 for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++)
549 omap_hwmod_shutdown(oh);
551 od->_state = OMAP_DEVICE_STATE_SHUTDOWN;
557 * omap_device_align_pm_lat - activate/deactivate device to match wakeup lat lim
558 * @od: struct omap_device *
560 * When a device's maximum wakeup latency limit changes, call some of
561 * the .activate_func or .deactivate_func function pointers in the
562 * omap_device's pm_lats array to ensure that the device's maximum
563 * wakeup latency is less than or equal to the new latency limit.
564 * Intended to be called by OMAP PM code whenever a device's maximum
565 * wakeup latency limit changes (e.g., via
566 * omap_pm_set_dev_wakeup_lat()). Returns 0 if nothing needs to be
567 * done (e.g., if the omap_device is not currently idle, or if the
568 * wakeup latency is already current with the new limit) or passes
569 * along the return value of _omap_device_deactivate() or
570 * _omap_device_activate().
572 int omap_device_align_pm_lat(struct platform_device *pdev,
573 u32 new_wakeup_lat_limit)
576 struct omap_device *od;
578 od = _find_by_pdev(pdev);
580 if (new_wakeup_lat_limit == od->dev_wakeup_lat)
583 od->_dev_wakeup_lat_limit = new_wakeup_lat_limit;
585 if (od->_state != OMAP_DEVICE_STATE_IDLE)
587 else if (new_wakeup_lat_limit > od->dev_wakeup_lat)
588 ret = _omap_device_deactivate(od, USE_WAKEUP_LAT);
589 else if (new_wakeup_lat_limit < od->dev_wakeup_lat)
590 ret = _omap_device_activate(od, USE_WAKEUP_LAT);
596 * omap_device_is_valid - Check if pointer is a valid omap_device
597 * @od: struct omap_device *
599 * Return whether struct omap_device pointer @od points to a valid
602 bool omap_device_is_valid(struct omap_device *od)
604 return (od && od->magic == OMAP_DEVICE_MAGIC);
608 * omap_device_get_pwrdm - return the powerdomain * associated with @od
609 * @od: struct omap_device *
611 * Return the powerdomain associated with the first underlying
612 * omap_hwmod for this omap_device. Intended for use by core OMAP PM
613 * code. Returns NULL on error or a struct powerdomain * upon
616 struct powerdomain *omap_device_get_pwrdm(struct omap_device *od)
619 * XXX Assumes that all omap_hwmod powerdomains are identical.
620 * This may not necessarily be true. There should be a sanity
621 * check in here to WARN() if any difference appears.
626 return omap_hwmod_get_pwrdm(od->hwmods[0]);
630 * Public functions intended for use in omap_device_pm_latency
631 * .activate_func and .deactivate_func function pointers
635 * omap_device_enable_hwmods - call omap_hwmod_enable() on all hwmods
636 * @od: struct omap_device *od
638 * Enable all underlying hwmods. Returns 0.
640 int omap_device_enable_hwmods(struct omap_device *od)
642 struct omap_hwmod *oh;
645 for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++)
646 omap_hwmod_enable(oh);
648 /* XXX pass along return value here? */
653 * omap_device_idle_hwmods - call omap_hwmod_idle() on all hwmods
654 * @od: struct omap_device *od
656 * Idle all underlying hwmods. Returns 0.
658 int omap_device_idle_hwmods(struct omap_device *od)
660 struct omap_hwmod *oh;
663 for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++)
666 /* XXX pass along return value here? */
671 * omap_device_disable_clocks - disable all main and interface clocks
672 * @od: struct omap_device *od
674 * Disable the main functional clock and interface clock for all of the
675 * omap_hwmods associated with the omap_device. Returns 0.
677 int omap_device_disable_clocks(struct omap_device *od)
679 struct omap_hwmod *oh;
682 for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++)
683 omap_hwmod_disable_clocks(oh);
685 /* XXX pass along return value here? */
690 * omap_device_enable_clocks - enable all main and interface clocks
691 * @od: struct omap_device *od
693 * Enable the main functional clock and interface clock for all of the
694 * omap_hwmods associated with the omap_device. Returns 0.
696 int omap_device_enable_clocks(struct omap_device *od)
698 struct omap_hwmod *oh;
701 for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++)
702 omap_hwmod_enable_clocks(oh);
704 /* XXX pass along return value here? */