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 /* Private functions */
96 * _omap_device_activate - increase device readiness
97 * @od: struct omap_device *
98 * @ignore_lat: increase to latency target (0) or full readiness (1)?
100 * Increase readiness of omap_device @od (thus decreasing device
101 * wakeup latency, but consuming more power). If @ignore_lat is
102 * IGNORE_WAKEUP_LAT, make the omap_device fully active. Otherwise,
103 * if @ignore_lat is USE_WAKEUP_LAT, and the device's maximum wakeup
104 * latency is greater than the requested maximum wakeup latency, step
105 * backwards in the omap_device_pm_latency table to ensure the
106 * device's maximum wakeup latency is less than or equal to the
107 * requested maximum wakeup latency. Returns 0.
109 static int _omap_device_activate(struct omap_device *od, u8 ignore_lat)
111 struct timespec a, b, c;
113 pr_debug("omap_device: %s: activating\n", od->pdev.name);
115 while (od->pm_lat_level > 0) {
116 struct omap_device_pm_latency *odpl;
117 unsigned long long act_lat = 0;
121 odpl = od->pm_lats + od->pm_lat_level;
124 (od->dev_wakeup_lat <= od->_dev_wakeup_lat_limit))
127 read_persistent_clock(&a);
129 /* XXX check return code */
130 odpl->activate_func(od);
132 read_persistent_clock(&b);
134 c = timespec_sub(b, a);
135 act_lat = timespec_to_ns(&c);
137 pr_debug("omap_device: %s: pm_lat %d: activate: elapsed time "
138 "%llu nsec\n", od->pdev.name, od->pm_lat_level,
141 WARN(act_lat > odpl->activate_lat, "omap_device: %s.%d: "
142 "activate step %d took longer than expected (%llu > %d)\n",
143 od->pdev.name, od->pdev.id, od->pm_lat_level,
144 act_lat, odpl->activate_lat);
146 od->dev_wakeup_lat -= odpl->activate_lat;
153 * _omap_device_deactivate - decrease device readiness
154 * @od: struct omap_device *
155 * @ignore_lat: decrease to latency target (0) or full inactivity (1)?
157 * Decrease readiness of omap_device @od (thus increasing device
158 * wakeup latency, but conserving power). If @ignore_lat is
159 * IGNORE_WAKEUP_LAT, make the omap_device fully inactive. Otherwise,
160 * if @ignore_lat is USE_WAKEUP_LAT, and the device's maximum wakeup
161 * latency is less than the requested maximum wakeup latency, step
162 * forwards in the omap_device_pm_latency table to ensure the device's
163 * maximum wakeup latency is less than or equal to the requested
164 * maximum wakeup latency. Returns 0.
166 static int _omap_device_deactivate(struct omap_device *od, u8 ignore_lat)
168 struct timespec a, b, c;
170 pr_debug("omap_device: %s: deactivating\n", od->pdev.name);
172 while (od->pm_lat_level < od->pm_lats_cnt) {
173 struct omap_device_pm_latency *odpl;
174 unsigned long long deact_lat = 0;
176 odpl = od->pm_lats + od->pm_lat_level;
179 ((od->dev_wakeup_lat + odpl->activate_lat) >
180 od->_dev_wakeup_lat_limit))
183 read_persistent_clock(&a);
185 /* XXX check return code */
186 odpl->deactivate_func(od);
188 read_persistent_clock(&b);
190 c = timespec_sub(b, a);
191 deact_lat = timespec_to_ns(&c);
193 pr_debug("omap_device: %s: pm_lat %d: deactivate: elapsed time "
194 "%llu nsec\n", od->pdev.name, od->pm_lat_level,
197 WARN(deact_lat > odpl->deactivate_lat, "omap_device: %s.%d: "
198 "deactivate step %d took longer than expected "
199 "(%llu > %d)\n", od->pdev.name, od->pdev.id,
200 od->pm_lat_level, deact_lat, odpl->deactivate_lat);
202 od->dev_wakeup_lat += odpl->activate_lat;
210 static inline struct omap_device *_find_by_pdev(struct platform_device *pdev)
212 return container_of(pdev, struct omap_device, pdev);
216 /* Public functions for use by core code */
219 * omap_device_count_resources - count number of struct resource entries needed
220 * @od: struct omap_device *
222 * Count the number of struct resource entries needed for this
223 * omap_device @od. Used by omap_device_build_ss() to determine how
224 * much memory to allocate before calling
225 * omap_device_fill_resources(). Returns the count.
227 int omap_device_count_resources(struct omap_device *od)
229 struct omap_hwmod *oh;
233 for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++)
234 c += omap_hwmod_count_resources(oh);
236 pr_debug("omap_device: %s: counted %d total resources across %d "
237 "hwmods\n", od->pdev.name, c, od->hwmods_cnt);
243 * omap_device_fill_resources - fill in array of struct resource
244 * @od: struct omap_device *
245 * @res: pointer to an array of struct resource to be filled in
247 * Populate one or more empty struct resource pointed to by @res with
248 * the resource data for this omap_device @od. Used by
249 * omap_device_build_ss() after calling omap_device_count_resources().
250 * Ideally this function would not be needed at all. If omap_device
251 * replaces platform_device, then we can specify our own
252 * get_resource()/ get_irq()/etc functions that use the underlying
253 * omap_hwmod information. Or if platform_device is extended to use
254 * subarchitecture-specific function pointers, the various
255 * platform_device functions can simply call omap_device internal
256 * functions to get device resources. Hacking around the existing
257 * platform_device code wastes memory. Returns 0.
259 int omap_device_fill_resources(struct omap_device *od, struct resource *res)
261 struct omap_hwmod *oh;
265 for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++) {
266 r = omap_hwmod_fill_resources(oh, res);
275 * omap_device_build - build and register an omap_device with one omap_hwmod
276 * @pdev_name: name of the platform_device driver to use
277 * @pdev_id: this platform_device's connection ID
278 * @oh: ptr to the single omap_hwmod that backs this omap_device
279 * @pdata: platform_data ptr to associate with the platform_device
280 * @pdata_len: amount of memory pointed to by @pdata
281 * @pm_lats: pointer to a omap_device_pm_latency array for this device
282 * @pm_lats_cnt: ARRAY_SIZE() of @pm_lats
284 * Convenience function for building and registering a single
285 * omap_device record, which in turn builds and registers a
286 * platform_device record. See omap_device_build_ss() for more
287 * information. Returns ERR_PTR(-EINVAL) if @oh is NULL; otherwise,
288 * passes along the return value of omap_device_build_ss().
290 struct omap_device *omap_device_build(const char *pdev_name, int pdev_id,
291 struct omap_hwmod *oh, void *pdata,
293 struct omap_device_pm_latency *pm_lats,
296 struct omap_hwmod *ohs[] = { oh };
299 return ERR_PTR(-EINVAL);
301 return omap_device_build_ss(pdev_name, pdev_id, ohs, 1, pdata,
302 pdata_len, pm_lats, pm_lats_cnt);
306 * omap_device_build_ss - build and register an omap_device with multiple hwmods
307 * @pdev_name: name of the platform_device driver to use
308 * @pdev_id: this platform_device's connection ID
309 * @oh: ptr to the single omap_hwmod that backs this omap_device
310 * @pdata: platform_data ptr to associate with the platform_device
311 * @pdata_len: amount of memory pointed to by @pdata
312 * @pm_lats: pointer to a omap_device_pm_latency array for this device
313 * @pm_lats_cnt: ARRAY_SIZE() of @pm_lats
315 * Convenience function for building and registering an omap_device
316 * subsystem record. Subsystem records consist of multiple
317 * omap_hwmods. This function in turn builds and registers a
318 * platform_device record. Returns an ERR_PTR() on error, or passes
319 * along the return value of omap_device_register().
321 struct omap_device *omap_device_build_ss(const char *pdev_name, int pdev_id,
322 struct omap_hwmod **ohs, int oh_cnt,
323 void *pdata, int pdata_len,
324 struct omap_device_pm_latency *pm_lats,
328 struct omap_device *od;
330 struct resource *res = NULL;
332 struct omap_hwmod **hwmods;
334 if (!ohs || oh_cnt == 0 || !pdev_name)
335 return ERR_PTR(-EINVAL);
337 if (!pdata && pdata_len > 0)
338 return ERR_PTR(-EINVAL);
340 pr_debug("omap_device: %s: building with %d hwmods\n", pdev_name,
343 od = kzalloc(sizeof(struct omap_device), GFP_KERNEL);
345 return ERR_PTR(-ENOMEM);
347 od->hwmods_cnt = oh_cnt;
349 hwmods = kzalloc(sizeof(struct omap_hwmod *) * oh_cnt,
354 memcpy(hwmods, ohs, sizeof(struct omap_hwmod *) * oh_cnt);
357 pdev_name2 = kzalloc(strlen(pdev_name) + 1, GFP_KERNEL);
360 strcpy(pdev_name2, pdev_name);
362 od->pdev.name = pdev_name2;
363 od->pdev.id = pdev_id;
365 res_count = omap_device_count_resources(od);
367 res = kzalloc(sizeof(struct resource) * res_count, GFP_KERNEL);
371 omap_device_fill_resources(od, res);
373 od->pdev.num_resources = res_count;
374 od->pdev.resource = res;
376 platform_device_add_data(&od->pdev, pdata, pdata_len);
378 od->pm_lats = pm_lats;
379 od->pm_lats_cnt = pm_lats_cnt;
381 ret = omap_device_register(od);
396 pr_err("omap_device: %s: build failed (%d)\n", pdev_name, ret);
402 * omap_device_register - register an omap_device with one omap_hwmod
403 * @od: struct omap_device * to register
405 * Register the omap_device structure. This currently just calls
406 * platform_device_register() on the underlying platform_device.
407 * Returns the return value of platform_device_register().
409 int omap_device_register(struct omap_device *od)
411 pr_debug("omap_device: %s: registering\n", od->pdev.name);
413 return platform_device_register(&od->pdev);
417 /* Public functions for use by device drivers through struct platform_data */
420 * omap_device_enable - fully activate an omap_device
421 * @od: struct omap_device * to activate
423 * Do whatever is necessary for the hwmods underlying omap_device @od
424 * to be accessible and ready to operate. This generally involves
425 * enabling clocks, setting SYSCONFIG registers; and in the future may
426 * involve remuxing pins. Device drivers should call this function
427 * (through platform_data function pointers) where they would normally
428 * enable clocks, etc. Returns -EINVAL if called when the omap_device
429 * is already enabled, or passes along the return value of
430 * _omap_device_activate().
432 int omap_device_enable(struct platform_device *pdev)
435 struct omap_device *od;
437 od = _find_by_pdev(pdev);
439 if (od->_state == OMAP_DEVICE_STATE_ENABLED) {
440 WARN(1, "omap_device: %s.%d: omap_device_enable() called from "
441 "invalid state\n", od->pdev.name, od->pdev.id);
445 /* Enable everything if we're enabling this device from scratch */
446 if (od->_state == OMAP_DEVICE_STATE_UNKNOWN)
447 od->pm_lat_level = od->pm_lats_cnt;
449 ret = _omap_device_activate(od, IGNORE_WAKEUP_LAT);
451 od->dev_wakeup_lat = 0;
452 od->_dev_wakeup_lat_limit = UINT_MAX;
453 od->_state = OMAP_DEVICE_STATE_ENABLED;
459 * omap_device_idle - idle an omap_device
460 * @od: struct omap_device * to idle
462 * Idle omap_device @od by calling as many .deactivate_func() entries
463 * in the omap_device's pm_lats table as is possible without exceeding
464 * the device's maximum wakeup latency limit, pm_lat_limit. Device
465 * drivers should call this function (through platform_data function
466 * pointers) where they would normally disable clocks after operations
467 * complete, etc.. Returns -EINVAL if the omap_device is not
468 * currently enabled, or passes along the return value of
469 * _omap_device_deactivate().
471 int omap_device_idle(struct platform_device *pdev)
474 struct omap_device *od;
476 od = _find_by_pdev(pdev);
478 if (od->_state != OMAP_DEVICE_STATE_ENABLED) {
479 WARN(1, "omap_device: %s.%d: omap_device_idle() called from "
480 "invalid state\n", od->pdev.name, od->pdev.id);
484 ret = _omap_device_deactivate(od, USE_WAKEUP_LAT);
486 od->_state = OMAP_DEVICE_STATE_IDLE;
492 * omap_device_shutdown - shut down an omap_device
493 * @od: struct omap_device * to shut down
495 * Shut down omap_device @od by calling all .deactivate_func() entries
496 * in the omap_device's pm_lats table and then shutting down all of
497 * the underlying omap_hwmods. Used when a device is being "removed"
498 * or a device driver is being unloaded. Returns -EINVAL if the
499 * omap_device is not currently enabled or idle, or passes along the
500 * return value of _omap_device_deactivate().
502 int omap_device_shutdown(struct platform_device *pdev)
505 struct omap_device *od;
506 struct omap_hwmod *oh;
508 od = _find_by_pdev(pdev);
510 if (od->_state != OMAP_DEVICE_STATE_ENABLED &&
511 od->_state != OMAP_DEVICE_STATE_IDLE) {
512 WARN(1, "omap_device: %s.%d: omap_device_shutdown() called "
513 "from invalid state\n", od->pdev.name, od->pdev.id);
517 ret = _omap_device_deactivate(od, IGNORE_WAKEUP_LAT);
519 for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++)
520 omap_hwmod_shutdown(oh);
522 od->_state = OMAP_DEVICE_STATE_SHUTDOWN;
528 * omap_device_align_pm_lat - activate/deactivate device to match wakeup lat lim
529 * @od: struct omap_device *
531 * When a device's maximum wakeup latency limit changes, call some of
532 * the .activate_func or .deactivate_func function pointers in the
533 * omap_device's pm_lats array to ensure that the device's maximum
534 * wakeup latency is less than or equal to the new latency limit.
535 * Intended to be called by OMAP PM code whenever a device's maximum
536 * wakeup latency limit changes (e.g., via
537 * omap_pm_set_dev_wakeup_lat()). Returns 0 if nothing needs to be
538 * done (e.g., if the omap_device is not currently idle, or if the
539 * wakeup latency is already current with the new limit) or passes
540 * along the return value of _omap_device_deactivate() or
541 * _omap_device_activate().
543 int omap_device_align_pm_lat(struct platform_device *pdev,
544 u32 new_wakeup_lat_limit)
547 struct omap_device *od;
549 od = _find_by_pdev(pdev);
551 if (new_wakeup_lat_limit == od->dev_wakeup_lat)
554 od->_dev_wakeup_lat_limit = new_wakeup_lat_limit;
556 if (od->_state != OMAP_DEVICE_STATE_IDLE)
558 else if (new_wakeup_lat_limit > od->dev_wakeup_lat)
559 ret = _omap_device_deactivate(od, USE_WAKEUP_LAT);
560 else if (new_wakeup_lat_limit < od->dev_wakeup_lat)
561 ret = _omap_device_activate(od, USE_WAKEUP_LAT);
567 * omap_device_get_pwrdm - return the powerdomain * associated with @od
568 * @od: struct omap_device *
570 * Return the powerdomain associated with the first underlying
571 * omap_hwmod for this omap_device. Intended for use by core OMAP PM
572 * code. Returns NULL on error or a struct powerdomain * upon
575 struct powerdomain *omap_device_get_pwrdm(struct omap_device *od)
578 * XXX Assumes that all omap_hwmod powerdomains are identical.
579 * This may not necessarily be true. There should be a sanity
580 * check in here to WARN() if any difference appears.
585 return omap_hwmod_get_pwrdm(od->hwmods[0]);
589 * Public functions intended for use in omap_device_pm_latency
590 * .activate_func and .deactivate_func function pointers
594 * omap_device_enable_hwmods - call omap_hwmod_enable() on all hwmods
595 * @od: struct omap_device *od
597 * Enable all underlying hwmods. Returns 0.
599 int omap_device_enable_hwmods(struct omap_device *od)
601 struct omap_hwmod *oh;
604 for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++)
605 omap_hwmod_enable(oh);
607 /* XXX pass along return value here? */
612 * omap_device_idle_hwmods - call omap_hwmod_idle() on all hwmods
613 * @od: struct omap_device *od
615 * Idle all underlying hwmods. Returns 0.
617 int omap_device_idle_hwmods(struct omap_device *od)
619 struct omap_hwmod *oh;
622 for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++)
625 /* XXX pass along return value here? */
630 * omap_device_disable_clocks - disable all main and interface clocks
631 * @od: struct omap_device *od
633 * Disable the main functional clock and interface clock for all of the
634 * omap_hwmods associated with the omap_device. Returns 0.
636 int omap_device_disable_clocks(struct omap_device *od)
638 struct omap_hwmod *oh;
641 for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++)
642 omap_hwmod_disable_clocks(oh);
644 /* XXX pass along return value here? */
649 * omap_device_enable_clocks - enable all main and interface clocks
650 * @od: struct omap_device *od
652 * Enable the main functional clock and interface clock for all of the
653 * omap_hwmods associated with the omap_device. Returns 0.
655 int omap_device_enable_clocks(struct omap_device *od)
657 struct omap_hwmod *oh;
660 for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++)
661 omap_hwmod_enable_clocks(oh);
663 /* XXX pass along return value here? */