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/slab.h>
83 #include <linux/err.h>
86 #include <plat/omap_device.h>
87 #include <plat/omap_hwmod.h>
89 /* These parameters are passed to _omap_device_{de,}activate() */
90 #define USE_WAKEUP_LAT 0
91 #define IGNORE_WAKEUP_LAT 1
94 #define OMAP_DEVICE_MAGIC 0xf00dcafe
96 /* Private functions */
99 * _omap_device_activate - increase device readiness
100 * @od: struct omap_device *
101 * @ignore_lat: increase to latency target (0) or full readiness (1)?
103 * Increase readiness of omap_device @od (thus decreasing device
104 * wakeup latency, but consuming more power). If @ignore_lat is
105 * IGNORE_WAKEUP_LAT, make the omap_device fully active. Otherwise,
106 * if @ignore_lat is USE_WAKEUP_LAT, and the device's maximum wakeup
107 * latency is greater than the requested maximum wakeup latency, step
108 * backwards in the omap_device_pm_latency table to ensure the
109 * device's maximum wakeup latency is less than or equal to the
110 * requested maximum wakeup latency. Returns 0.
112 static int _omap_device_activate(struct omap_device
*od
, u8 ignore_lat
)
114 struct timespec a
, b
, c
;
116 pr_debug("omap_device: %s: activating\n", od
->pdev
.name
);
118 while (od
->pm_lat_level
> 0) {
119 struct omap_device_pm_latency
*odpl
;
120 unsigned long long act_lat
= 0;
124 odpl
= od
->pm_lats
+ od
->pm_lat_level
;
127 (od
->dev_wakeup_lat
<= od
->_dev_wakeup_lat_limit
))
130 read_persistent_clock(&a
);
132 /* XXX check return code */
133 odpl
->activate_func(od
);
135 read_persistent_clock(&b
);
137 c
= timespec_sub(b
, a
);
138 act_lat
= timespec_to_ns(&c
);
140 pr_debug("omap_device: %s: pm_lat %d: activate: elapsed time "
141 "%llu nsec\n", od
->pdev
.name
, od
->pm_lat_level
,
144 if (act_lat
> odpl
->activate_lat
) {
145 odpl
->activate_lat_worst
= act_lat
;
146 if (odpl
->flags
& OMAP_DEVICE_LATENCY_AUTO_ADJUST
) {
147 odpl
->activate_lat
= act_lat
;
148 pr_warning("omap_device: %s.%d: new worst case "
149 "activate latency %d: %llu\n",
150 od
->pdev
.name
, od
->pdev
.id
,
151 od
->pm_lat_level
, act_lat
);
153 pr_warning("omap_device: %s.%d: activate "
154 "latency %d higher than exptected. "
156 od
->pdev
.name
, od
->pdev
.id
,
157 od
->pm_lat_level
, act_lat
,
161 od
->dev_wakeup_lat
-= odpl
->activate_lat
;
168 * _omap_device_deactivate - decrease device readiness
169 * @od: struct omap_device *
170 * @ignore_lat: decrease to latency target (0) or full inactivity (1)?
172 * Decrease readiness of omap_device @od (thus increasing device
173 * wakeup latency, but conserving power). If @ignore_lat is
174 * IGNORE_WAKEUP_LAT, make the omap_device fully inactive. Otherwise,
175 * if @ignore_lat is USE_WAKEUP_LAT, and the device's maximum wakeup
176 * latency is less than the requested maximum wakeup latency, step
177 * forwards in the omap_device_pm_latency table to ensure the device's
178 * maximum wakeup latency is less than or equal to the requested
179 * maximum wakeup latency. Returns 0.
181 static int _omap_device_deactivate(struct omap_device
*od
, u8 ignore_lat
)
183 struct timespec a
, b
, c
;
185 pr_debug("omap_device: %s: deactivating\n", od
->pdev
.name
);
187 while (od
->pm_lat_level
< od
->pm_lats_cnt
) {
188 struct omap_device_pm_latency
*odpl
;
189 unsigned long long deact_lat
= 0;
191 odpl
= od
->pm_lats
+ od
->pm_lat_level
;
194 ((od
->dev_wakeup_lat
+ odpl
->activate_lat
) >
195 od
->_dev_wakeup_lat_limit
))
198 read_persistent_clock(&a
);
200 /* XXX check return code */
201 odpl
->deactivate_func(od
);
203 read_persistent_clock(&b
);
205 c
= timespec_sub(b
, a
);
206 deact_lat
= timespec_to_ns(&c
);
208 pr_debug("omap_device: %s: pm_lat %d: deactivate: elapsed time "
209 "%llu nsec\n", od
->pdev
.name
, od
->pm_lat_level
,
212 if (deact_lat
> odpl
->deactivate_lat
) {
213 odpl
->deactivate_lat_worst
= deact_lat
;
214 if (odpl
->flags
& OMAP_DEVICE_LATENCY_AUTO_ADJUST
) {
215 odpl
->deactivate_lat
= deact_lat
;
216 pr_warning("omap_device: %s.%d: new worst case "
217 "deactivate latency %d: %llu\n",
218 od
->pdev
.name
, od
->pdev
.id
,
219 od
->pm_lat_level
, deact_lat
);
221 pr_warning("omap_device: %s.%d: deactivate "
222 "latency %d higher than exptected. "
224 od
->pdev
.name
, od
->pdev
.id
,
225 od
->pm_lat_level
, deact_lat
,
226 odpl
->deactivate_lat
);
230 od
->dev_wakeup_lat
+= odpl
->activate_lat
;
238 static inline struct omap_device
*_find_by_pdev(struct platform_device
*pdev
)
240 return container_of(pdev
, struct omap_device
, pdev
);
244 /* Public functions for use by core code */
247 * omap_device_count_resources - count number of struct resource entries needed
248 * @od: struct omap_device *
250 * Count the number of struct resource entries needed for this
251 * omap_device @od. Used by omap_device_build_ss() to determine how
252 * much memory to allocate before calling
253 * omap_device_fill_resources(). Returns the count.
255 int omap_device_count_resources(struct omap_device
*od
)
257 struct omap_hwmod
*oh
;
261 for (i
= 0, oh
= *od
->hwmods
; i
< od
->hwmods_cnt
; i
++, oh
++)
262 c
+= omap_hwmod_count_resources(oh
);
264 pr_debug("omap_device: %s: counted %d total resources across %d "
265 "hwmods\n", od
->pdev
.name
, c
, od
->hwmods_cnt
);
271 * omap_device_fill_resources - fill in array of struct resource
272 * @od: struct omap_device *
273 * @res: pointer to an array of struct resource to be filled in
275 * Populate one or more empty struct resource pointed to by @res with
276 * the resource data for this omap_device @od. Used by
277 * omap_device_build_ss() after calling omap_device_count_resources().
278 * Ideally this function would not be needed at all. If omap_device
279 * replaces platform_device, then we can specify our own
280 * get_resource()/ get_irq()/etc functions that use the underlying
281 * omap_hwmod information. Or if platform_device is extended to use
282 * subarchitecture-specific function pointers, the various
283 * platform_device functions can simply call omap_device internal
284 * functions to get device resources. Hacking around the existing
285 * platform_device code wastes memory. Returns 0.
287 int omap_device_fill_resources(struct omap_device
*od
, struct resource
*res
)
289 struct omap_hwmod
*oh
;
293 for (i
= 0, oh
= *od
->hwmods
; i
< od
->hwmods_cnt
; i
++, oh
++) {
294 r
= omap_hwmod_fill_resources(oh
, res
);
303 * omap_device_build - build and register an omap_device with one omap_hwmod
304 * @pdev_name: name of the platform_device driver to use
305 * @pdev_id: this platform_device's connection ID
306 * @oh: ptr to the single omap_hwmod that backs this omap_device
307 * @pdata: platform_data ptr to associate with the platform_device
308 * @pdata_len: amount of memory pointed to by @pdata
309 * @pm_lats: pointer to a omap_device_pm_latency array for this device
310 * @pm_lats_cnt: ARRAY_SIZE() of @pm_lats
311 * @is_early_device: should the device be registered as an early device or not
313 * Convenience function for building and registering a single
314 * omap_device record, which in turn builds and registers a
315 * platform_device record. See omap_device_build_ss() for more
316 * information. Returns ERR_PTR(-EINVAL) if @oh is NULL; otherwise,
317 * passes along the return value of omap_device_build_ss().
319 struct omap_device
*omap_device_build(const char *pdev_name
, int pdev_id
,
320 struct omap_hwmod
*oh
, void *pdata
,
322 struct omap_device_pm_latency
*pm_lats
,
323 int pm_lats_cnt
, int is_early_device
)
325 struct omap_hwmod
*ohs
[] = { oh
};
328 return ERR_PTR(-EINVAL
);
330 return omap_device_build_ss(pdev_name
, pdev_id
, ohs
, 1, pdata
,
331 pdata_len
, pm_lats
, pm_lats_cnt
,
336 * omap_device_build_ss - build and register an omap_device with multiple hwmods
337 * @pdev_name: name of the platform_device driver to use
338 * @pdev_id: this platform_device's connection ID
339 * @oh: ptr to the single omap_hwmod that backs this omap_device
340 * @pdata: platform_data ptr to associate with the platform_device
341 * @pdata_len: amount of memory pointed to by @pdata
342 * @pm_lats: pointer to a omap_device_pm_latency array for this device
343 * @pm_lats_cnt: ARRAY_SIZE() of @pm_lats
344 * @is_early_device: should the device be registered as an early device or not
346 * Convenience function for building and registering an omap_device
347 * subsystem record. Subsystem records consist of multiple
348 * omap_hwmods. This function in turn builds and registers a
349 * platform_device record. Returns an ERR_PTR() on error, or passes
350 * along the return value of omap_device_register().
352 struct omap_device
*omap_device_build_ss(const char *pdev_name
, int pdev_id
,
353 struct omap_hwmod
**ohs
, int oh_cnt
,
354 void *pdata
, int pdata_len
,
355 struct omap_device_pm_latency
*pm_lats
,
356 int pm_lats_cnt
, int is_early_device
)
359 struct omap_device
*od
;
361 struct resource
*res
= NULL
;
363 struct omap_hwmod
**hwmods
;
365 if (!ohs
|| oh_cnt
== 0 || !pdev_name
)
366 return ERR_PTR(-EINVAL
);
368 if (!pdata
&& pdata_len
> 0)
369 return ERR_PTR(-EINVAL
);
371 pr_debug("omap_device: %s: building with %d hwmods\n", pdev_name
,
374 od
= kzalloc(sizeof(struct omap_device
), GFP_KERNEL
);
376 return ERR_PTR(-ENOMEM
);
378 od
->hwmods_cnt
= oh_cnt
;
380 hwmods
= kzalloc(sizeof(struct omap_hwmod
*) * oh_cnt
,
385 memcpy(hwmods
, ohs
, sizeof(struct omap_hwmod
*) * oh_cnt
);
388 pdev_name2
= kzalloc(strlen(pdev_name
) + 1, GFP_KERNEL
);
391 strcpy(pdev_name2
, pdev_name
);
393 od
->pdev
.name
= pdev_name2
;
394 od
->pdev
.id
= pdev_id
;
396 res_count
= omap_device_count_resources(od
);
398 res
= kzalloc(sizeof(struct resource
) * res_count
, GFP_KERNEL
);
402 omap_device_fill_resources(od
, res
);
404 od
->pdev
.num_resources
= res_count
;
405 od
->pdev
.resource
= res
;
407 platform_device_add_data(&od
->pdev
, pdata
, pdata_len
);
409 od
->pm_lats
= pm_lats
;
410 od
->pm_lats_cnt
= pm_lats_cnt
;
412 od
->magic
= OMAP_DEVICE_MAGIC
;
415 ret
= omap_early_device_register(od
);
417 ret
= omap_device_register(od
);
433 pr_err("omap_device: %s: build failed (%d)\n", pdev_name
, ret
);
439 * omap_early_device_register - register an omap_device as an early platform
441 * @od: struct omap_device * to register
443 * Register the omap_device structure. This currently just calls
444 * platform_early_add_device() on the underlying platform_device.
445 * Returns 0 by default.
447 int omap_early_device_register(struct omap_device
*od
)
449 struct platform_device
*devices
[1];
451 devices
[0] = &(od
->pdev
);
452 early_platform_add_devices(devices
, 1);
457 * omap_device_register - register an omap_device with one omap_hwmod
458 * @od: struct omap_device * to register
460 * Register the omap_device structure. This currently just calls
461 * platform_device_register() on the underlying platform_device.
462 * Returns the return value of platform_device_register().
464 int omap_device_register(struct omap_device
*od
)
466 pr_debug("omap_device: %s: registering\n", od
->pdev
.name
);
468 return platform_device_register(&od
->pdev
);
472 /* Public functions for use by device drivers through struct platform_data */
475 * omap_device_enable - fully activate an omap_device
476 * @od: struct omap_device * to activate
478 * Do whatever is necessary for the hwmods underlying omap_device @od
479 * to be accessible and ready to operate. This generally involves
480 * enabling clocks, setting SYSCONFIG registers; and in the future may
481 * involve remuxing pins. Device drivers should call this function
482 * (through platform_data function pointers) where they would normally
483 * enable clocks, etc. Returns -EINVAL if called when the omap_device
484 * is already enabled, or passes along the return value of
485 * _omap_device_activate().
487 int omap_device_enable(struct platform_device
*pdev
)
490 struct omap_device
*od
;
492 od
= _find_by_pdev(pdev
);
494 if (od
->_state
== OMAP_DEVICE_STATE_ENABLED
) {
495 WARN(1, "omap_device: %s.%d: %s() called from invalid state %d\n",
496 od
->pdev
.name
, od
->pdev
.id
, __func__
, od
->_state
);
500 /* Enable everything if we're enabling this device from scratch */
501 if (od
->_state
== OMAP_DEVICE_STATE_UNKNOWN
)
502 od
->pm_lat_level
= od
->pm_lats_cnt
;
504 ret
= _omap_device_activate(od
, IGNORE_WAKEUP_LAT
);
506 od
->dev_wakeup_lat
= 0;
507 od
->_dev_wakeup_lat_limit
= UINT_MAX
;
508 od
->_state
= OMAP_DEVICE_STATE_ENABLED
;
514 * omap_device_idle - idle an omap_device
515 * @od: struct omap_device * to idle
517 * Idle omap_device @od by calling as many .deactivate_func() entries
518 * in the omap_device's pm_lats table as is possible without exceeding
519 * the device's maximum wakeup latency limit, pm_lat_limit. Device
520 * drivers should call this function (through platform_data function
521 * pointers) where they would normally disable clocks after operations
522 * complete, etc.. Returns -EINVAL if the omap_device is not
523 * currently enabled, or passes along the return value of
524 * _omap_device_deactivate().
526 int omap_device_idle(struct platform_device
*pdev
)
529 struct omap_device
*od
;
531 od
= _find_by_pdev(pdev
);
533 if (od
->_state
!= OMAP_DEVICE_STATE_ENABLED
) {
534 WARN(1, "omap_device: %s.%d: %s() called from invalid state %d\n",
535 od
->pdev
.name
, od
->pdev
.id
, __func__
, od
->_state
);
539 ret
= _omap_device_deactivate(od
, USE_WAKEUP_LAT
);
541 od
->_state
= OMAP_DEVICE_STATE_IDLE
;
547 * omap_device_shutdown - shut down an omap_device
548 * @od: struct omap_device * to shut down
550 * Shut down omap_device @od by calling all .deactivate_func() entries
551 * in the omap_device's pm_lats table and then shutting down all of
552 * the underlying omap_hwmods. Used when a device is being "removed"
553 * or a device driver is being unloaded. Returns -EINVAL if the
554 * omap_device is not currently enabled or idle, or passes along the
555 * return value of _omap_device_deactivate().
557 int omap_device_shutdown(struct platform_device
*pdev
)
560 struct omap_device
*od
;
561 struct omap_hwmod
*oh
;
563 od
= _find_by_pdev(pdev
);
565 if (od
->_state
!= OMAP_DEVICE_STATE_ENABLED
&&
566 od
->_state
!= OMAP_DEVICE_STATE_IDLE
) {
567 WARN(1, "omap_device: %s.%d: %s() called from invalid state %d\n",
568 od
->pdev
.name
, od
->pdev
.id
, __func__
, od
->_state
);
572 ret
= _omap_device_deactivate(od
, IGNORE_WAKEUP_LAT
);
574 for (i
= 0, oh
= *od
->hwmods
; i
< od
->hwmods_cnt
; i
++, oh
++)
575 omap_hwmod_shutdown(oh
);
577 od
->_state
= OMAP_DEVICE_STATE_SHUTDOWN
;
583 * omap_device_align_pm_lat - activate/deactivate device to match wakeup lat lim
584 * @od: struct omap_device *
586 * When a device's maximum wakeup latency limit changes, call some of
587 * the .activate_func or .deactivate_func function pointers in the
588 * omap_device's pm_lats array to ensure that the device's maximum
589 * wakeup latency is less than or equal to the new latency limit.
590 * Intended to be called by OMAP PM code whenever a device's maximum
591 * wakeup latency limit changes (e.g., via
592 * omap_pm_set_dev_wakeup_lat()). Returns 0 if nothing needs to be
593 * done (e.g., if the omap_device is not currently idle, or if the
594 * wakeup latency is already current with the new limit) or passes
595 * along the return value of _omap_device_deactivate() or
596 * _omap_device_activate().
598 int omap_device_align_pm_lat(struct platform_device
*pdev
,
599 u32 new_wakeup_lat_limit
)
602 struct omap_device
*od
;
604 od
= _find_by_pdev(pdev
);
606 if (new_wakeup_lat_limit
== od
->dev_wakeup_lat
)
609 od
->_dev_wakeup_lat_limit
= new_wakeup_lat_limit
;
611 if (od
->_state
!= OMAP_DEVICE_STATE_IDLE
)
613 else if (new_wakeup_lat_limit
> od
->dev_wakeup_lat
)
614 ret
= _omap_device_deactivate(od
, USE_WAKEUP_LAT
);
615 else if (new_wakeup_lat_limit
< od
->dev_wakeup_lat
)
616 ret
= _omap_device_activate(od
, USE_WAKEUP_LAT
);
622 * omap_device_is_valid - Check if pointer is a valid omap_device
623 * @od: struct omap_device *
625 * Return whether struct omap_device pointer @od points to a valid
628 bool omap_device_is_valid(struct omap_device
*od
)
630 return (od
&& od
->magic
== OMAP_DEVICE_MAGIC
);
634 * omap_device_get_pwrdm - return the powerdomain * associated with @od
635 * @od: struct omap_device *
637 * Return the powerdomain associated with the first underlying
638 * omap_hwmod for this omap_device. Intended for use by core OMAP PM
639 * code. Returns NULL on error or a struct powerdomain * upon
642 struct powerdomain
*omap_device_get_pwrdm(struct omap_device
*od
)
645 * XXX Assumes that all omap_hwmod powerdomains are identical.
646 * This may not necessarily be true. There should be a sanity
647 * check in here to WARN() if any difference appears.
652 return omap_hwmod_get_pwrdm(od
->hwmods
[0]);
656 * Public functions intended for use in omap_device_pm_latency
657 * .activate_func and .deactivate_func function pointers
661 * omap_device_enable_hwmods - call omap_hwmod_enable() on all hwmods
662 * @od: struct omap_device *od
664 * Enable all underlying hwmods. Returns 0.
666 int omap_device_enable_hwmods(struct omap_device
*od
)
668 struct omap_hwmod
*oh
;
671 for (i
= 0, oh
= *od
->hwmods
; i
< od
->hwmods_cnt
; i
++, oh
++)
672 omap_hwmod_enable(oh
);
674 /* XXX pass along return value here? */
679 * omap_device_idle_hwmods - call omap_hwmod_idle() on all hwmods
680 * @od: struct omap_device *od
682 * Idle all underlying hwmods. Returns 0.
684 int omap_device_idle_hwmods(struct omap_device
*od
)
686 struct omap_hwmod
*oh
;
689 for (i
= 0, oh
= *od
->hwmods
; i
< od
->hwmods_cnt
; i
++, oh
++)
692 /* XXX pass along return value here? */
697 * omap_device_disable_clocks - disable all main and interface clocks
698 * @od: struct omap_device *od
700 * Disable the main functional clock and interface clock for all of the
701 * omap_hwmods associated with the omap_device. Returns 0.
703 int omap_device_disable_clocks(struct omap_device
*od
)
705 struct omap_hwmod
*oh
;
708 for (i
= 0, oh
= *od
->hwmods
; i
< od
->hwmods_cnt
; i
++, oh
++)
709 omap_hwmod_disable_clocks(oh
);
711 /* XXX pass along return value here? */
716 * omap_device_enable_clocks - enable all main and interface clocks
717 * @od: struct omap_device *od
719 * Enable the main functional clock and interface clock for all of the
720 * omap_hwmods associated with the omap_device. Returns 0.
722 int omap_device_enable_clocks(struct omap_device
*od
)
724 struct omap_hwmod
*oh
;
727 for (i
= 0, oh
= *od
->hwmods
; i
< od
->hwmods_cnt
; i
++, oh
++)
728 omap_hwmod_enable_clocks(oh
);
730 /* XXX pass along return value here? */