2 * linux/arch/arm/common/amba.c
4 * Copyright (C) 2003 Deep Blue Solutions Ltd, All Rights Reserved.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/device.h>
13 #include <linux/string.h>
14 #include <linux/slab.h>
17 #include <linux/pm_runtime.h>
18 #include <linux/amba/bus.h>
21 #include <asm/sizes.h>
23 #define to_amba_driver(d) container_of(d, struct amba_driver, drv)
25 static const struct amba_id *
26 amba_lookup(const struct amba_id *table, struct amba_device *dev)
31 ret = (dev->periphid & table->mask) == table->id;
37 return ret ? table : NULL;
40 static int amba_match(struct device *dev, struct device_driver *drv)
42 struct amba_device *pcdev = to_amba_device(dev);
43 struct amba_driver *pcdrv = to_amba_driver(drv);
45 return amba_lookup(pcdrv->id_table, pcdev) != NULL;
49 static int amba_uevent(struct device *dev, struct kobj_uevent_env *env)
51 struct amba_device *pcdev = to_amba_device(dev);
54 retval = add_uevent_var(env, "AMBA_ID=%08x", pcdev->periphid);
58 retval = add_uevent_var(env, "MODALIAS=amba:d%08X", pcdev->periphid);
62 #define amba_uevent NULL
65 #define amba_attr_func(name,fmt,arg...) \
66 static ssize_t name##_show(struct device *_dev, \
67 struct device_attribute *attr, char *buf) \
69 struct amba_device *dev = to_amba_device(_dev); \
70 return sprintf(buf, fmt, arg); \
73 #define amba_attr(name,fmt,arg...) \
74 amba_attr_func(name,fmt,arg) \
75 static DEVICE_ATTR(name, S_IRUGO, name##_show, NULL)
77 amba_attr_func(id, "%08x\n", dev->periphid);
78 amba_attr(irq0, "%u\n", dev->irq[0]);
79 amba_attr(irq1, "%u\n", dev->irq[1]);
80 amba_attr_func(resource, "\t%016llx\t%016llx\t%016lx\n",
81 (unsigned long long)dev->res.start, (unsigned long long)dev->res.end,
84 static struct device_attribute amba_dev_attrs[] = {
90 #ifdef CONFIG_PM_SLEEP
92 static int amba_legacy_suspend(struct device *dev, pm_message_t mesg)
94 struct amba_driver *adrv = to_amba_driver(dev->driver);
95 struct amba_device *adev = to_amba_device(dev);
98 if (dev->driver && adrv->suspend)
99 ret = adrv->suspend(adev, mesg);
104 static int amba_legacy_resume(struct device *dev)
106 struct amba_driver *adrv = to_amba_driver(dev->driver);
107 struct amba_device *adev = to_amba_device(dev);
110 if (dev->driver && adrv->resume)
111 ret = adrv->resume(adev);
116 #endif /* CONFIG_PM_SLEEP */
118 #ifdef CONFIG_SUSPEND
120 static int amba_pm_suspend(struct device *dev)
122 struct device_driver *drv = dev->driver;
129 if (drv->pm->suspend)
130 ret = drv->pm->suspend(dev);
132 ret = amba_legacy_suspend(dev, PMSG_SUSPEND);
138 static int amba_pm_resume(struct device *dev)
140 struct device_driver *drv = dev->driver;
148 ret = drv->pm->resume(dev);
150 ret = amba_legacy_resume(dev);
156 #else /* !CONFIG_SUSPEND */
158 #define amba_pm_suspend NULL
159 #define amba_pm_resume NULL
161 #endif /* !CONFIG_SUSPEND */
163 #ifdef CONFIG_HIBERNATE_CALLBACKS
165 static int amba_pm_freeze(struct device *dev)
167 struct device_driver *drv = dev->driver;
175 ret = drv->pm->freeze(dev);
177 ret = amba_legacy_suspend(dev, PMSG_FREEZE);
183 static int amba_pm_thaw(struct device *dev)
185 struct device_driver *drv = dev->driver;
193 ret = drv->pm->thaw(dev);
195 ret = amba_legacy_resume(dev);
201 static int amba_pm_poweroff(struct device *dev)
203 struct device_driver *drv = dev->driver;
210 if (drv->pm->poweroff)
211 ret = drv->pm->poweroff(dev);
213 ret = amba_legacy_suspend(dev, PMSG_HIBERNATE);
219 static int amba_pm_restore(struct device *dev)
221 struct device_driver *drv = dev->driver;
228 if (drv->pm->restore)
229 ret = drv->pm->restore(dev);
231 ret = amba_legacy_resume(dev);
237 #else /* !CONFIG_HIBERNATE_CALLBACKS */
239 #define amba_pm_freeze NULL
240 #define amba_pm_thaw NULL
241 #define amba_pm_poweroff NULL
242 #define amba_pm_restore NULL
244 #endif /* !CONFIG_HIBERNATE_CALLBACKS */
246 #ifdef CONFIG_PM_RUNTIME
248 * Hooks to provide runtime PM of the pclk (bus clock). It is safe to
249 * enable/disable the bus clock at runtime PM suspend/resume as this
250 * does not result in loss of context. However, disabling vcore power
251 * would do, so we leave that to the driver.
253 static int amba_pm_runtime_suspend(struct device *dev)
255 struct amba_device *pcdev = to_amba_device(dev);
256 int ret = pm_generic_runtime_suspend(dev);
258 if (ret == 0 && dev->driver)
259 clk_disable(pcdev->pclk);
264 static int amba_pm_runtime_resume(struct device *dev)
266 struct amba_device *pcdev = to_amba_device(dev);
270 ret = clk_enable(pcdev->pclk);
271 /* Failure is probably fatal to the system, but... */
276 return pm_generic_runtime_resume(dev);
282 static const struct dev_pm_ops amba_pm = {
283 .suspend = amba_pm_suspend,
284 .resume = amba_pm_resume,
285 .freeze = amba_pm_freeze,
286 .thaw = amba_pm_thaw,
287 .poweroff = amba_pm_poweroff,
288 .restore = amba_pm_restore,
290 amba_pm_runtime_suspend,
291 amba_pm_runtime_resume,
292 pm_generic_runtime_idle
296 #define AMBA_PM (&amba_pm)
298 #else /* !CONFIG_PM */
302 #endif /* !CONFIG_PM */
305 * Primecells are part of the Advanced Microcontroller Bus Architecture,
306 * so we call the bus "amba".
308 struct bus_type amba_bustype = {
310 .dev_attrs = amba_dev_attrs,
312 .uevent = amba_uevent,
316 static int __init amba_init(void)
318 return bus_register(&amba_bustype);
321 postcore_initcall(amba_init);
323 static int amba_get_enable_pclk(struct amba_device *pcdev)
325 struct clk *pclk = clk_get(&pcdev->dev, "apb_pclk");
331 return PTR_ERR(pclk);
333 ret = clk_prepare(pclk);
339 ret = clk_enable(pclk);
348 static void amba_put_disable_pclk(struct amba_device *pcdev)
350 struct clk *pclk = pcdev->pclk;
357 static int amba_get_enable_vcore(struct amba_device *pcdev)
359 struct regulator *vcore = regulator_get(&pcdev->dev, "vcore");
362 pcdev->vcore = vcore;
365 /* It is OK not to supply a vcore regulator */
366 if (PTR_ERR(vcore) == -ENODEV)
368 return PTR_ERR(vcore);
371 ret = regulator_enable(vcore);
373 regulator_put(vcore);
374 pcdev->vcore = ERR_PTR(-ENODEV);
380 static void amba_put_disable_vcore(struct amba_device *pcdev)
382 struct regulator *vcore = pcdev->vcore;
384 if (!IS_ERR(vcore)) {
385 regulator_disable(vcore);
386 regulator_put(vcore);
391 * These are the device model conversion veneers; they convert the
392 * device model structures to our more specific structures.
394 static int amba_probe(struct device *dev)
396 struct amba_device *pcdev = to_amba_device(dev);
397 struct amba_driver *pcdrv = to_amba_driver(dev->driver);
398 const struct amba_id *id = amba_lookup(pcdrv->id_table, pcdev);
402 ret = amba_get_enable_vcore(pcdev);
406 ret = amba_get_enable_pclk(pcdev);
410 pm_runtime_get_noresume(dev);
411 pm_runtime_set_active(dev);
412 pm_runtime_enable(dev);
414 ret = pcdrv->probe(pcdev, id);
418 pm_runtime_disable(dev);
419 pm_runtime_set_suspended(dev);
420 pm_runtime_put_noidle(dev);
422 amba_put_disable_pclk(pcdev);
423 amba_put_disable_vcore(pcdev);
429 static int amba_remove(struct device *dev)
431 struct amba_device *pcdev = to_amba_device(dev);
432 struct amba_driver *drv = to_amba_driver(dev->driver);
435 pm_runtime_get_sync(dev);
436 ret = drv->remove(pcdev);
437 pm_runtime_put_noidle(dev);
439 /* Undo the runtime PM settings in amba_probe() */
440 pm_runtime_disable(dev);
441 pm_runtime_set_suspended(dev);
442 pm_runtime_put_noidle(dev);
444 amba_put_disable_pclk(pcdev);
445 amba_put_disable_vcore(pcdev);
450 static void amba_shutdown(struct device *dev)
452 struct amba_driver *drv = to_amba_driver(dev->driver);
453 drv->shutdown(to_amba_device(dev));
457 * amba_driver_register - register an AMBA device driver
458 * @drv: amba device driver structure
460 * Register an AMBA device driver with the Linux device model
461 * core. If devices pre-exist, the drivers probe function will
464 int amba_driver_register(struct amba_driver *drv)
466 drv->drv.bus = &amba_bustype;
468 #define SETFN(fn) if (drv->fn) drv->drv.fn = amba_##fn
473 return driver_register(&drv->drv);
477 * amba_driver_unregister - remove an AMBA device driver
478 * @drv: AMBA device driver structure to remove
480 * Unregister an AMBA device driver from the Linux device
481 * model. The device model will call the drivers remove function
482 * for each device the device driver is currently handling.
484 void amba_driver_unregister(struct amba_driver *drv)
486 driver_unregister(&drv->drv);
490 static void amba_device_release(struct device *dev)
492 struct amba_device *d = to_amba_device(dev);
495 release_resource(&d->res);
500 * amba_device_register - register an AMBA device
501 * @dev: AMBA device to register
502 * @parent: parent memory resource
504 * Setup the AMBA device, reading the cell ID if present.
505 * Claim the resource, and register the AMBA device with
506 * the Linux device manager.
508 int amba_device_register(struct amba_device *dev, struct resource *parent)
514 device_initialize(&dev->dev);
517 * Copy from device_add
519 if (dev->dev.init_name) {
520 dev_set_name(&dev->dev, "%s", dev->dev.init_name);
521 dev->dev.init_name = NULL;
524 dev->dev.release = amba_device_release;
525 dev->dev.bus = &amba_bustype;
526 dev->dev.dma_mask = &dev->dma_mask;
527 dev->res.name = dev_name(&dev->dev);
529 if (!dev->dev.coherent_dma_mask && dev->dma_mask)
530 dev_warn(&dev->dev, "coherent dma mask is unset\n");
532 ret = request_resource(parent, &dev->res);
536 /* Hard-coded primecell ID instead of plug-n-play */
537 if (dev->periphid != 0)
541 * Dynamically calculate the size of the resource
542 * and use this for iomap
544 size = resource_size(&dev->res);
545 tmp = ioremap(dev->res.start, size);
551 ret = amba_get_enable_pclk(dev);
556 * Read pid and cid based on size of resource
557 * they are located at end of region
559 for (pid = 0, i = 0; i < 4; i++)
560 pid |= (readl(tmp + size - 0x20 + 4 * i) & 255) <<
562 for (cid = 0, i = 0; i < 4; i++)
563 cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) <<
566 amba_put_disable_pclk(dev);
581 ret = device_add(&dev->dev);
585 if (dev->irq[0] != NO_IRQ)
586 ret = device_create_file(&dev->dev, &dev_attr_irq0);
587 if (ret == 0 && dev->irq[1] != NO_IRQ)
588 ret = device_create_file(&dev->dev, &dev_attr_irq1);
592 device_unregister(&dev->dev);
595 release_resource(&dev->res);
601 * amba_device_unregister - unregister an AMBA device
602 * @dev: AMBA device to remove
604 * Remove the specified AMBA device from the Linux device
605 * manager. All files associated with this object will be
606 * destroyed, and device drivers notified that the device has
607 * been removed. The AMBA device's resources including
608 * the amba_device structure will be freed once all
609 * references to it have been dropped.
611 void amba_device_unregister(struct amba_device *dev)
613 device_unregister(&dev->dev);
618 struct amba_device *dev;
619 struct device *parent;
625 static int amba_find_match(struct device *dev, void *data)
627 struct find_data *d = data;
628 struct amba_device *pcdev = to_amba_device(dev);
631 r = (pcdev->periphid & d->mask) == d->id;
633 r &= d->parent == dev->parent;
635 r &= strcmp(dev_name(dev), d->busid) == 0;
646 * amba_find_device - locate an AMBA device given a bus id
647 * @busid: bus id for device (or NULL)
648 * @parent: parent device (or NULL)
649 * @id: peripheral ID (or 0)
650 * @mask: peripheral ID mask (or 0)
652 * Return the AMBA device corresponding to the supplied parameters.
653 * If no device matches, returns NULL.
655 * NOTE: When a valid device is found, its refcount is
656 * incremented, and must be decremented before the returned
660 amba_find_device(const char *busid, struct device *parent, unsigned int id,
663 struct find_data data;
666 data.parent = parent;
671 bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match);
677 * amba_request_regions - request all mem regions associated with device
678 * @dev: amba_device structure for device
679 * @name: name, or NULL to use driver name
681 int amba_request_regions(struct amba_device *dev, const char *name)
687 name = dev->dev.driver->name;
689 size = resource_size(&dev->res);
691 if (!request_mem_region(dev->res.start, size, name))
698 * amba_release_regions - release mem regions associated with device
699 * @dev: amba_device structure for device
701 * Release regions claimed by a successful call to amba_request_regions.
703 void amba_release_regions(struct amba_device *dev)
707 size = resource_size(&dev->res);
708 release_mem_region(dev->res.start, size);
711 EXPORT_SYMBOL(amba_driver_register);
712 EXPORT_SYMBOL(amba_driver_unregister);
713 EXPORT_SYMBOL(amba_device_register);
714 EXPORT_SYMBOL(amba_device_unregister);
715 EXPORT_SYMBOL(amba_find_device);
716 EXPORT_SYMBOL(amba_request_regions);
717 EXPORT_SYMBOL(amba_release_regions);