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/pm_domain.h>
19 #include <linux/amba/bus.h>
20 #include <linux/sizes.h>
21 #include <linux/limits.h>
22 #include <linux/clk/clk-conf.h>
23 #include <linux/platform_device.h>
27 #define to_amba_driver(d) container_of(d, struct amba_driver, drv)
29 /* called on periphid match and class 0x9 coresight device. */
31 amba_cs_uci_id_match(const struct amba_id *table, struct amba_device *dev)
34 struct amba_cs_uci_id *uci;
38 /* no table data or zero mask - return match on periphid */
39 if (!uci || (uci->devarch_mask == 0))
42 /* test against read devtype and masked devarch value */
43 ret = (dev->uci.devtype == uci->devtype) &&
44 ((dev->uci.devarch & uci->devarch_mask) == uci->devarch);
48 static const struct amba_id *
49 amba_lookup(const struct amba_id *table, struct amba_device *dev)
52 if (((dev->periphid & table->mask) == table->id) &&
53 ((dev->cid != CORESIGHT_CID) ||
54 (amba_cs_uci_id_match(table, dev))))
61 static int amba_match(struct device *dev, struct device_driver *drv)
63 struct amba_device *pcdev = to_amba_device(dev);
64 struct amba_driver *pcdrv = to_amba_driver(drv);
66 /* When driver_override is set, only bind to the matching driver */
67 if (pcdev->driver_override)
68 return !strcmp(pcdev->driver_override, drv->name);
70 return amba_lookup(pcdrv->id_table, pcdev) != NULL;
73 static int amba_uevent(struct device *dev, struct kobj_uevent_env *env)
75 struct amba_device *pcdev = to_amba_device(dev);
78 retval = add_uevent_var(env, "AMBA_ID=%08x", pcdev->periphid);
82 retval = add_uevent_var(env, "MODALIAS=amba:d%08X", pcdev->periphid);
86 static ssize_t driver_override_show(struct device *_dev,
87 struct device_attribute *attr, char *buf)
89 struct amba_device *dev = to_amba_device(_dev);
93 len = sprintf(buf, "%s\n", dev->driver_override);
98 static ssize_t driver_override_store(struct device *_dev,
99 struct device_attribute *attr,
100 const char *buf, size_t count)
102 struct amba_device *dev = to_amba_device(_dev);
103 char *driver_override, *old, *cp;
105 /* We need to keep extra room for a newline */
106 if (count >= (PAGE_SIZE - 1))
109 driver_override = kstrndup(buf, count, GFP_KERNEL);
110 if (!driver_override)
113 cp = strchr(driver_override, '\n');
118 old = dev->driver_override;
119 if (strlen(driver_override)) {
120 dev->driver_override = driver_override;
122 kfree(driver_override);
123 dev->driver_override = NULL;
131 static DEVICE_ATTR_RW(driver_override);
133 #define amba_attr_func(name,fmt,arg...) \
134 static ssize_t name##_show(struct device *_dev, \
135 struct device_attribute *attr, char *buf) \
137 struct amba_device *dev = to_amba_device(_dev); \
138 return sprintf(buf, fmt, arg); \
140 static DEVICE_ATTR_RO(name)
142 amba_attr_func(id, "%08x\n", dev->periphid);
143 amba_attr_func(irq0, "%u\n", dev->irq[0]);
144 amba_attr_func(irq1, "%u\n", dev->irq[1]);
145 amba_attr_func(resource, "\t%016llx\t%016llx\t%016lx\n",
146 (unsigned long long)dev->res.start, (unsigned long long)dev->res.end,
149 static struct attribute *amba_dev_attrs[] = {
151 &dev_attr_resource.attr,
152 &dev_attr_driver_override.attr,
155 ATTRIBUTE_GROUPS(amba_dev);
159 * Hooks to provide runtime PM of the pclk (bus clock). It is safe to
160 * enable/disable the bus clock at runtime PM suspend/resume as this
161 * does not result in loss of context.
163 static int amba_pm_runtime_suspend(struct device *dev)
165 struct amba_device *pcdev = to_amba_device(dev);
166 int ret = pm_generic_runtime_suspend(dev);
168 if (ret == 0 && dev->driver) {
169 if (pm_runtime_is_irq_safe(dev))
170 clk_disable(pcdev->pclk);
172 clk_disable_unprepare(pcdev->pclk);
178 static int amba_pm_runtime_resume(struct device *dev)
180 struct amba_device *pcdev = to_amba_device(dev);
184 if (pm_runtime_is_irq_safe(dev))
185 ret = clk_enable(pcdev->pclk);
187 ret = clk_prepare_enable(pcdev->pclk);
188 /* Failure is probably fatal to the system, but... */
193 return pm_generic_runtime_resume(dev);
195 #endif /* CONFIG_PM */
197 static const struct dev_pm_ops amba_pm = {
198 .suspend = pm_generic_suspend,
199 .resume = pm_generic_resume,
200 .freeze = pm_generic_freeze,
201 .thaw = pm_generic_thaw,
202 .poweroff = pm_generic_poweroff,
203 .restore = pm_generic_restore,
205 amba_pm_runtime_suspend,
206 amba_pm_runtime_resume,
212 * Primecells are part of the Advanced Microcontroller Bus Architecture,
213 * so we call the bus "amba".
214 * DMA configuration for platform and AMBA bus is same. So here we reuse
215 * platform's DMA config routine.
217 struct bus_type amba_bustype = {
219 .dev_groups = amba_dev_groups,
221 .uevent = amba_uevent,
222 .dma_configure = platform_dma_configure,
225 EXPORT_SYMBOL_GPL(amba_bustype);
227 static int __init amba_init(void)
229 return bus_register(&amba_bustype);
232 postcore_initcall(amba_init);
234 static int amba_get_enable_pclk(struct amba_device *pcdev)
238 pcdev->pclk = clk_get(&pcdev->dev, "apb_pclk");
239 if (IS_ERR(pcdev->pclk))
240 return PTR_ERR(pcdev->pclk);
242 ret = clk_prepare_enable(pcdev->pclk);
244 clk_put(pcdev->pclk);
249 static void amba_put_disable_pclk(struct amba_device *pcdev)
251 clk_disable_unprepare(pcdev->pclk);
252 clk_put(pcdev->pclk);
256 * These are the device model conversion veneers; they convert the
257 * device model structures to our more specific structures.
259 static int amba_probe(struct device *dev)
261 struct amba_device *pcdev = to_amba_device(dev);
262 struct amba_driver *pcdrv = to_amba_driver(dev->driver);
263 const struct amba_id *id = amba_lookup(pcdrv->id_table, pcdev);
267 ret = of_clk_set_defaults(dev->of_node, false);
271 ret = dev_pm_domain_attach(dev, true);
275 ret = amba_get_enable_pclk(pcdev);
277 dev_pm_domain_detach(dev, true);
281 pm_runtime_get_noresume(dev);
282 pm_runtime_set_active(dev);
283 pm_runtime_enable(dev);
285 ret = pcdrv->probe(pcdev, id);
289 pm_runtime_disable(dev);
290 pm_runtime_set_suspended(dev);
291 pm_runtime_put_noidle(dev);
293 amba_put_disable_pclk(pcdev);
294 dev_pm_domain_detach(dev, true);
300 static int amba_remove(struct device *dev)
302 struct amba_device *pcdev = to_amba_device(dev);
303 struct amba_driver *drv = to_amba_driver(dev->driver);
306 pm_runtime_get_sync(dev);
307 ret = drv->remove(pcdev);
308 pm_runtime_put_noidle(dev);
310 /* Undo the runtime PM settings in amba_probe() */
311 pm_runtime_disable(dev);
312 pm_runtime_set_suspended(dev);
313 pm_runtime_put_noidle(dev);
315 amba_put_disable_pclk(pcdev);
316 dev_pm_domain_detach(dev, true);
321 static void amba_shutdown(struct device *dev)
323 struct amba_driver *drv = to_amba_driver(dev->driver);
324 drv->shutdown(to_amba_device(dev));
328 * amba_driver_register - register an AMBA device driver
329 * @drv: amba device driver structure
331 * Register an AMBA device driver with the Linux device model
332 * core. If devices pre-exist, the drivers probe function will
335 int amba_driver_register(struct amba_driver *drv)
337 drv->drv.bus = &amba_bustype;
339 #define SETFN(fn) if (drv->fn) drv->drv.fn = amba_##fn
344 return driver_register(&drv->drv);
348 * amba_driver_unregister - remove an AMBA device driver
349 * @drv: AMBA device driver structure to remove
351 * Unregister an AMBA device driver from the Linux device
352 * model. The device model will call the drivers remove function
353 * for each device the device driver is currently handling.
355 void amba_driver_unregister(struct amba_driver *drv)
357 driver_unregister(&drv->drv);
361 static void amba_device_release(struct device *dev)
363 struct amba_device *d = to_amba_device(dev);
366 release_resource(&d->res);
370 static int amba_device_try_add(struct amba_device *dev, struct resource *parent)
376 WARN_ON(dev->irq[0] == (unsigned int)-1);
377 WARN_ON(dev->irq[1] == (unsigned int)-1);
379 ret = request_resource(parent, &dev->res);
383 /* Hard-coded primecell ID instead of plug-n-play */
384 if (dev->periphid != 0)
388 * Dynamically calculate the size of the resource
389 * and use this for iomap
391 size = resource_size(&dev->res);
392 tmp = ioremap(dev->res.start, size);
398 ret = dev_pm_domain_attach(&dev->dev, true);
404 ret = amba_get_enable_pclk(dev);
409 * Read pid and cid based on size of resource
410 * they are located at end of region
412 for (pid = 0, i = 0; i < 4; i++)
413 pid |= (readl(tmp + size - 0x20 + 4 * i) & 255) <<
415 for (cid = 0, i = 0; i < 4; i++)
416 cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) <<
419 if (cid == CORESIGHT_CID) {
420 /* set the base to the start of the last 4k block */
421 void __iomem *csbase = tmp + size - 4096;
424 readl(csbase + UCI_REG_DEVARCH_OFFSET);
426 readl(csbase + UCI_REG_DEVTYPE_OFFSET) & 0xff;
429 amba_put_disable_pclk(dev);
431 if (cid == AMBA_CID || cid == CORESIGHT_CID) {
441 dev_pm_domain_detach(&dev->dev, true);
447 ret = device_add(&dev->dev);
452 ret = device_create_file(&dev->dev, &dev_attr_irq0);
453 if (ret == 0 && dev->irq[1])
454 ret = device_create_file(&dev->dev, &dev_attr_irq1);
458 device_unregister(&dev->dev);
461 release_resource(&dev->res);
467 * Registration of AMBA device require reading its pid and cid registers.
468 * To do this, the device must be turned on (if it is a part of power domain)
469 * and have clocks enabled. However in some cases those resources might not be
470 * yet available. Returning EPROBE_DEFER is not a solution in such case,
471 * because callers don't handle this special error code. Instead such devices
472 * are added to the special list and their registration is retried from
473 * periodic worker, until all resources are available and registration succeeds.
475 struct deferred_device {
476 struct amba_device *dev;
477 struct resource *parent;
478 struct list_head node;
481 static LIST_HEAD(deferred_devices);
482 static DEFINE_MUTEX(deferred_devices_lock);
484 static void amba_deferred_retry_func(struct work_struct *dummy);
485 static DECLARE_DELAYED_WORK(deferred_retry_work, amba_deferred_retry_func);
487 #define DEFERRED_DEVICE_TIMEOUT (msecs_to_jiffies(5 * 1000))
489 static void amba_deferred_retry_func(struct work_struct *dummy)
491 struct deferred_device *ddev, *tmp;
493 mutex_lock(&deferred_devices_lock);
495 list_for_each_entry_safe(ddev, tmp, &deferred_devices, node) {
496 int ret = amba_device_try_add(ddev->dev, ddev->parent);
498 if (ret == -EPROBE_DEFER)
501 list_del_init(&ddev->node);
505 if (!list_empty(&deferred_devices))
506 schedule_delayed_work(&deferred_retry_work,
507 DEFERRED_DEVICE_TIMEOUT);
509 mutex_unlock(&deferred_devices_lock);
513 * amba_device_add - add a previously allocated AMBA device structure
514 * @dev: AMBA device allocated by amba_device_alloc
515 * @parent: resource parent for this devices resources
517 * Claim the resource, and read the device cell ID if not already
518 * initialized. Register the AMBA device with the Linux device
521 int amba_device_add(struct amba_device *dev, struct resource *parent)
523 int ret = amba_device_try_add(dev, parent);
525 if (ret == -EPROBE_DEFER) {
526 struct deferred_device *ddev;
528 ddev = kmalloc(sizeof(*ddev), GFP_KERNEL);
533 ddev->parent = parent;
536 mutex_lock(&deferred_devices_lock);
538 if (list_empty(&deferred_devices))
539 schedule_delayed_work(&deferred_retry_work,
540 DEFERRED_DEVICE_TIMEOUT);
541 list_add_tail(&ddev->node, &deferred_devices);
543 mutex_unlock(&deferred_devices_lock);
547 EXPORT_SYMBOL_GPL(amba_device_add);
549 static struct amba_device *
550 amba_aphb_device_add(struct device *parent, const char *name,
551 resource_size_t base, size_t size, int irq1, int irq2,
552 void *pdata, unsigned int periphid, u64 dma_mask,
553 struct resource *resbase)
555 struct amba_device *dev;
558 dev = amba_device_alloc(name, base, size);
560 return ERR_PTR(-ENOMEM);
562 dev->dev.coherent_dma_mask = dma_mask;
565 dev->periphid = periphid;
566 dev->dev.platform_data = pdata;
567 dev->dev.parent = parent;
569 ret = amba_device_add(dev, resbase);
571 amba_device_put(dev);
579 amba_apb_device_add(struct device *parent, const char *name,
580 resource_size_t base, size_t size, int irq1, int irq2,
581 void *pdata, unsigned int periphid)
583 return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata,
584 periphid, 0, &iomem_resource);
586 EXPORT_SYMBOL_GPL(amba_apb_device_add);
589 amba_ahb_device_add(struct device *parent, const char *name,
590 resource_size_t base, size_t size, int irq1, int irq2,
591 void *pdata, unsigned int periphid)
593 return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata,
594 periphid, ~0ULL, &iomem_resource);
596 EXPORT_SYMBOL_GPL(amba_ahb_device_add);
599 amba_apb_device_add_res(struct device *parent, const char *name,
600 resource_size_t base, size_t size, int irq1,
601 int irq2, void *pdata, unsigned int periphid,
602 struct resource *resbase)
604 return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata,
605 periphid, 0, resbase);
607 EXPORT_SYMBOL_GPL(amba_apb_device_add_res);
610 amba_ahb_device_add_res(struct device *parent, const char *name,
611 resource_size_t base, size_t size, int irq1,
612 int irq2, void *pdata, unsigned int periphid,
613 struct resource *resbase)
615 return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata,
616 periphid, ~0ULL, resbase);
618 EXPORT_SYMBOL_GPL(amba_ahb_device_add_res);
621 static void amba_device_initialize(struct amba_device *dev, const char *name)
623 device_initialize(&dev->dev);
625 dev_set_name(&dev->dev, "%s", name);
626 dev->dev.release = amba_device_release;
627 dev->dev.bus = &amba_bustype;
628 dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
629 dev->res.name = dev_name(&dev->dev);
633 * amba_device_alloc - allocate an AMBA device
634 * @name: sysfs name of the AMBA device
635 * @base: base of AMBA device
636 * @size: size of AMBA device
638 * Allocate and initialize an AMBA device structure. Returns %NULL
641 struct amba_device *amba_device_alloc(const char *name, resource_size_t base,
644 struct amba_device *dev;
646 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
648 amba_device_initialize(dev, name);
649 dev->res.start = base;
650 dev->res.end = base + size - 1;
651 dev->res.flags = IORESOURCE_MEM;
656 EXPORT_SYMBOL_GPL(amba_device_alloc);
659 * amba_device_register - register an AMBA device
660 * @dev: AMBA device to register
661 * @parent: parent memory resource
663 * Setup the AMBA device, reading the cell ID if present.
664 * Claim the resource, and register the AMBA device with
665 * the Linux device manager.
667 int amba_device_register(struct amba_device *dev, struct resource *parent)
669 amba_device_initialize(dev, dev->dev.init_name);
670 dev->dev.init_name = NULL;
672 return amba_device_add(dev, parent);
676 * amba_device_put - put an AMBA device
677 * @dev: AMBA device to put
679 void amba_device_put(struct amba_device *dev)
681 put_device(&dev->dev);
683 EXPORT_SYMBOL_GPL(amba_device_put);
686 * amba_device_unregister - unregister an AMBA device
687 * @dev: AMBA device to remove
689 * Remove the specified AMBA device from the Linux device
690 * manager. All files associated with this object will be
691 * destroyed, and device drivers notified that the device has
692 * been removed. The AMBA device's resources including
693 * the amba_device structure will be freed once all
694 * references to it have been dropped.
696 void amba_device_unregister(struct amba_device *dev)
698 device_unregister(&dev->dev);
703 struct amba_device *dev;
704 struct device *parent;
710 static int amba_find_match(struct device *dev, void *data)
712 struct find_data *d = data;
713 struct amba_device *pcdev = to_amba_device(dev);
716 r = (pcdev->periphid & d->mask) == d->id;
718 r &= d->parent == dev->parent;
720 r &= strcmp(dev_name(dev), d->busid) == 0;
731 * amba_find_device - locate an AMBA device given a bus id
732 * @busid: bus id for device (or NULL)
733 * @parent: parent device (or NULL)
734 * @id: peripheral ID (or 0)
735 * @mask: peripheral ID mask (or 0)
737 * Return the AMBA device corresponding to the supplied parameters.
738 * If no device matches, returns NULL.
740 * NOTE: When a valid device is found, its refcount is
741 * incremented, and must be decremented before the returned
745 amba_find_device(const char *busid, struct device *parent, unsigned int id,
748 struct find_data data;
751 data.parent = parent;
756 bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match);
762 * amba_request_regions - request all mem regions associated with device
763 * @dev: amba_device structure for device
764 * @name: name, or NULL to use driver name
766 int amba_request_regions(struct amba_device *dev, const char *name)
772 name = dev->dev.driver->name;
774 size = resource_size(&dev->res);
776 if (!request_mem_region(dev->res.start, size, name))
783 * amba_release_regions - release mem regions associated with device
784 * @dev: amba_device structure for device
786 * Release regions claimed by a successful call to amba_request_regions.
788 void amba_release_regions(struct amba_device *dev)
792 size = resource_size(&dev->res);
793 release_mem_region(dev->res.start, size);
796 EXPORT_SYMBOL(amba_driver_register);
797 EXPORT_SYMBOL(amba_driver_unregister);
798 EXPORT_SYMBOL(amba_device_register);
799 EXPORT_SYMBOL(amba_device_unregister);
800 EXPORT_SYMBOL(amba_find_device);
801 EXPORT_SYMBOL(amba_request_regions);
802 EXPORT_SYMBOL(amba_release_regions);