]>
git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - drivers/amba/bus.c
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>
26 #define to_amba_driver(d) container_of(d, struct amba_driver, drv)
28 static const struct amba_id
*
29 amba_lookup(const struct amba_id
*table
, struct amba_device
*dev
)
34 ret
= (dev
->periphid
& table
->mask
) == table
->id
;
40 return ret
? table
: NULL
;
43 static int amba_match(struct device
*dev
, struct device_driver
*drv
)
45 struct amba_device
*pcdev
= to_amba_device(dev
);
46 struct amba_driver
*pcdrv
= to_amba_driver(drv
);
48 /* When driver_override is set, only bind to the matching driver */
49 if (pcdev
->driver_override
)
50 return !strcmp(pcdev
->driver_override
, drv
->name
);
52 return amba_lookup(pcdrv
->id_table
, pcdev
) != NULL
;
55 static int amba_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
57 struct amba_device
*pcdev
= to_amba_device(dev
);
60 retval
= add_uevent_var(env
, "AMBA_ID=%08x", pcdev
->periphid
);
64 retval
= add_uevent_var(env
, "MODALIAS=amba:d%08X", pcdev
->periphid
);
68 static ssize_t
driver_override_show(struct device
*_dev
,
69 struct device_attribute
*attr
, char *buf
)
71 struct amba_device
*dev
= to_amba_device(_dev
);
73 if (!dev
->driver_override
)
76 return sprintf(buf
, "%s\n", dev
->driver_override
);
79 static ssize_t
driver_override_store(struct device
*_dev
,
80 struct device_attribute
*attr
,
81 const char *buf
, size_t count
)
83 struct amba_device
*dev
= to_amba_device(_dev
);
84 char *driver_override
, *old
= dev
->driver_override
, *cp
;
89 driver_override
= kstrndup(buf
, count
, GFP_KERNEL
);
93 cp
= strchr(driver_override
, '\n');
97 if (strlen(driver_override
)) {
98 dev
->driver_override
= driver_override
;
100 kfree(driver_override
);
101 dev
->driver_override
= NULL
;
108 static DEVICE_ATTR_RW(driver_override
);
110 #define amba_attr_func(name,fmt,arg...) \
111 static ssize_t name##_show(struct device *_dev, \
112 struct device_attribute *attr, char *buf) \
114 struct amba_device *dev = to_amba_device(_dev); \
115 return sprintf(buf, fmt, arg); \
117 static DEVICE_ATTR_RO(name)
119 amba_attr_func(id
, "%08x\n", dev
->periphid
);
120 amba_attr_func(irq0
, "%u\n", dev
->irq
[0]);
121 amba_attr_func(irq1
, "%u\n", dev
->irq
[1]);
122 amba_attr_func(resource
, "\t%016llx\t%016llx\t%016lx\n",
123 (unsigned long long)dev
->res
.start
, (unsigned long long)dev
->res
.end
,
126 static struct attribute
*amba_dev_attrs
[] = {
128 &dev_attr_resource
.attr
,
129 &dev_attr_driver_override
.attr
,
132 ATTRIBUTE_GROUPS(amba_dev
);
136 * Hooks to provide runtime PM of the pclk (bus clock). It is safe to
137 * enable/disable the bus clock at runtime PM suspend/resume as this
138 * does not result in loss of context.
140 static int amba_pm_runtime_suspend(struct device
*dev
)
142 struct amba_device
*pcdev
= to_amba_device(dev
);
143 int ret
= pm_generic_runtime_suspend(dev
);
145 if (ret
== 0 && dev
->driver
) {
146 if (pm_runtime_is_irq_safe(dev
))
147 clk_disable(pcdev
->pclk
);
149 clk_disable_unprepare(pcdev
->pclk
);
155 static int amba_pm_runtime_resume(struct device
*dev
)
157 struct amba_device
*pcdev
= to_amba_device(dev
);
161 if (pm_runtime_is_irq_safe(dev
))
162 ret
= clk_enable(pcdev
->pclk
);
164 ret
= clk_prepare_enable(pcdev
->pclk
);
165 /* Failure is probably fatal to the system, but... */
170 return pm_generic_runtime_resume(dev
);
172 #endif /* CONFIG_PM */
174 static const struct dev_pm_ops amba_pm
= {
175 .suspend
= pm_generic_suspend
,
176 .resume
= pm_generic_resume
,
177 .freeze
= pm_generic_freeze
,
178 .thaw
= pm_generic_thaw
,
179 .poweroff
= pm_generic_poweroff
,
180 .restore
= pm_generic_restore
,
182 amba_pm_runtime_suspend
,
183 amba_pm_runtime_resume
,
189 * Primecells are part of the Advanced Microcontroller Bus Architecture,
190 * so we call the bus "amba".
192 struct bus_type amba_bustype
= {
194 .dev_groups
= amba_dev_groups
,
196 .uevent
= amba_uevent
,
200 static int __init
amba_init(void)
202 return bus_register(&amba_bustype
);
205 postcore_initcall(amba_init
);
207 static int amba_get_enable_pclk(struct amba_device
*pcdev
)
211 pcdev
->pclk
= clk_get(&pcdev
->dev
, "apb_pclk");
212 if (IS_ERR(pcdev
->pclk
))
213 return PTR_ERR(pcdev
->pclk
);
215 ret
= clk_prepare_enable(pcdev
->pclk
);
217 clk_put(pcdev
->pclk
);
222 static void amba_put_disable_pclk(struct amba_device
*pcdev
)
224 clk_disable_unprepare(pcdev
->pclk
);
225 clk_put(pcdev
->pclk
);
229 * These are the device model conversion veneers; they convert the
230 * device model structures to our more specific structures.
232 static int amba_probe(struct device
*dev
)
234 struct amba_device
*pcdev
= to_amba_device(dev
);
235 struct amba_driver
*pcdrv
= to_amba_driver(dev
->driver
);
236 const struct amba_id
*id
= amba_lookup(pcdrv
->id_table
, pcdev
);
240 ret
= of_clk_set_defaults(dev
->of_node
, false);
244 ret
= dev_pm_domain_attach(dev
, true);
245 if (ret
== -EPROBE_DEFER
)
248 ret
= amba_get_enable_pclk(pcdev
);
250 dev_pm_domain_detach(dev
, true);
254 pm_runtime_get_noresume(dev
);
255 pm_runtime_set_active(dev
);
256 pm_runtime_enable(dev
);
258 ret
= pcdrv
->probe(pcdev
, id
);
262 pm_runtime_disable(dev
);
263 pm_runtime_set_suspended(dev
);
264 pm_runtime_put_noidle(dev
);
266 amba_put_disable_pclk(pcdev
);
267 dev_pm_domain_detach(dev
, true);
273 static int amba_remove(struct device
*dev
)
275 struct amba_device
*pcdev
= to_amba_device(dev
);
276 struct amba_driver
*drv
= to_amba_driver(dev
->driver
);
279 pm_runtime_get_sync(dev
);
280 ret
= drv
->remove(pcdev
);
281 pm_runtime_put_noidle(dev
);
283 /* Undo the runtime PM settings in amba_probe() */
284 pm_runtime_disable(dev
);
285 pm_runtime_set_suspended(dev
);
286 pm_runtime_put_noidle(dev
);
288 amba_put_disable_pclk(pcdev
);
289 dev_pm_domain_detach(dev
, true);
294 static void amba_shutdown(struct device
*dev
)
296 struct amba_driver
*drv
= to_amba_driver(dev
->driver
);
297 drv
->shutdown(to_amba_device(dev
));
301 * amba_driver_register - register an AMBA device driver
302 * @drv: amba device driver structure
304 * Register an AMBA device driver with the Linux device model
305 * core. If devices pre-exist, the drivers probe function will
308 int amba_driver_register(struct amba_driver
*drv
)
310 drv
->drv
.bus
= &amba_bustype
;
312 #define SETFN(fn) if (drv->fn) drv->drv.fn = amba_##fn
317 return driver_register(&drv
->drv
);
321 * amba_driver_unregister - remove an AMBA device driver
322 * @drv: AMBA device driver structure to remove
324 * Unregister an AMBA device driver from the Linux device
325 * model. The device model will call the drivers remove function
326 * for each device the device driver is currently handling.
328 void amba_driver_unregister(struct amba_driver
*drv
)
330 driver_unregister(&drv
->drv
);
334 static void amba_device_release(struct device
*dev
)
336 struct amba_device
*d
= to_amba_device(dev
);
339 release_resource(&d
->res
);
343 static int amba_device_try_add(struct amba_device
*dev
, struct resource
*parent
)
349 WARN_ON(dev
->irq
[0] == (unsigned int)-1);
350 WARN_ON(dev
->irq
[1] == (unsigned int)-1);
352 ret
= request_resource(parent
, &dev
->res
);
356 /* Hard-coded primecell ID instead of plug-n-play */
357 if (dev
->periphid
!= 0)
361 * Dynamically calculate the size of the resource
362 * and use this for iomap
364 size
= resource_size(&dev
->res
);
365 tmp
= ioremap(dev
->res
.start
, size
);
371 ret
= dev_pm_domain_attach(&dev
->dev
, true);
372 if (ret
== -EPROBE_DEFER
) {
377 ret
= amba_get_enable_pclk(dev
);
382 * Read pid and cid based on size of resource
383 * they are located at end of region
385 for (pid
= 0, i
= 0; i
< 4; i
++)
386 pid
|= (readl(tmp
+ size
- 0x20 + 4 * i
) & 255) <<
388 for (cid
= 0, i
= 0; i
< 4; i
++)
389 cid
|= (readl(tmp
+ size
- 0x10 + 4 * i
) & 255) <<
392 amba_put_disable_pclk(dev
);
394 if (cid
== AMBA_CID
|| cid
== CORESIGHT_CID
)
402 dev_pm_domain_detach(&dev
->dev
, true);
408 ret
= device_add(&dev
->dev
);
413 ret
= device_create_file(&dev
->dev
, &dev_attr_irq0
);
414 if (ret
== 0 && dev
->irq
[1])
415 ret
= device_create_file(&dev
->dev
, &dev_attr_irq1
);
419 device_unregister(&dev
->dev
);
422 release_resource(&dev
->res
);
428 * Registration of AMBA device require reading its pid and cid registers.
429 * To do this, the device must be turned on (if it is a part of power domain)
430 * and have clocks enabled. However in some cases those resources might not be
431 * yet available. Returning EPROBE_DEFER is not a solution in such case,
432 * because callers don't handle this special error code. Instead such devices
433 * are added to the special list and their registration is retried from
434 * periodic worker, until all resources are available and registration succeeds.
436 struct deferred_device
{
437 struct amba_device
*dev
;
438 struct resource
*parent
;
439 struct list_head node
;
442 static LIST_HEAD(deferred_devices
);
443 static DEFINE_MUTEX(deferred_devices_lock
);
445 static void amba_deferred_retry_func(struct work_struct
*dummy
);
446 static DECLARE_DELAYED_WORK(deferred_retry_work
, amba_deferred_retry_func
);
448 #define DEFERRED_DEVICE_TIMEOUT (msecs_to_jiffies(5 * 1000))
450 static void amba_deferred_retry_func(struct work_struct
*dummy
)
452 struct deferred_device
*ddev
, *tmp
;
454 mutex_lock(&deferred_devices_lock
);
456 list_for_each_entry_safe(ddev
, tmp
, &deferred_devices
, node
) {
457 int ret
= amba_device_try_add(ddev
->dev
, ddev
->parent
);
459 if (ret
== -EPROBE_DEFER
)
462 list_del_init(&ddev
->node
);
466 if (!list_empty(&deferred_devices
))
467 schedule_delayed_work(&deferred_retry_work
,
468 DEFERRED_DEVICE_TIMEOUT
);
470 mutex_unlock(&deferred_devices_lock
);
474 * amba_device_add - add a previously allocated AMBA device structure
475 * @dev: AMBA device allocated by amba_device_alloc
476 * @parent: resource parent for this devices resources
478 * Claim the resource, and read the device cell ID if not already
479 * initialized. Register the AMBA device with the Linux device
482 int amba_device_add(struct amba_device
*dev
, struct resource
*parent
)
484 int ret
= amba_device_try_add(dev
, parent
);
486 if (ret
== -EPROBE_DEFER
) {
487 struct deferred_device
*ddev
;
489 ddev
= kmalloc(sizeof(*ddev
), GFP_KERNEL
);
494 ddev
->parent
= parent
;
497 mutex_lock(&deferred_devices_lock
);
499 if (list_empty(&deferred_devices
))
500 schedule_delayed_work(&deferred_retry_work
,
501 DEFERRED_DEVICE_TIMEOUT
);
502 list_add_tail(&ddev
->node
, &deferred_devices
);
504 mutex_unlock(&deferred_devices_lock
);
508 EXPORT_SYMBOL_GPL(amba_device_add
);
510 static struct amba_device
*
511 amba_aphb_device_add(struct device
*parent
, const char *name
,
512 resource_size_t base
, size_t size
, int irq1
, int irq2
,
513 void *pdata
, unsigned int periphid
, u64 dma_mask
,
514 struct resource
*resbase
)
516 struct amba_device
*dev
;
519 dev
= amba_device_alloc(name
, base
, size
);
521 return ERR_PTR(-ENOMEM
);
523 dev
->dev
.coherent_dma_mask
= dma_mask
;
526 dev
->periphid
= periphid
;
527 dev
->dev
.platform_data
= pdata
;
528 dev
->dev
.parent
= parent
;
530 ret
= amba_device_add(dev
, resbase
);
532 amba_device_put(dev
);
540 amba_apb_device_add(struct device
*parent
, const char *name
,
541 resource_size_t base
, size_t size
, int irq1
, int irq2
,
542 void *pdata
, unsigned int periphid
)
544 return amba_aphb_device_add(parent
, name
, base
, size
, irq1
, irq2
, pdata
,
545 periphid
, 0, &iomem_resource
);
547 EXPORT_SYMBOL_GPL(amba_apb_device_add
);
550 amba_ahb_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
)
554 return amba_aphb_device_add(parent
, name
, base
, size
, irq1
, irq2
, pdata
,
555 periphid
, ~0ULL, &iomem_resource
);
557 EXPORT_SYMBOL_GPL(amba_ahb_device_add
);
560 amba_apb_device_add_res(struct device
*parent
, const char *name
,
561 resource_size_t base
, size_t size
, int irq1
,
562 int irq2
, void *pdata
, unsigned int periphid
,
563 struct resource
*resbase
)
565 return amba_aphb_device_add(parent
, name
, base
, size
, irq1
, irq2
, pdata
,
566 periphid
, 0, resbase
);
568 EXPORT_SYMBOL_GPL(amba_apb_device_add_res
);
571 amba_ahb_device_add_res(struct device
*parent
, const char *name
,
572 resource_size_t base
, size_t size
, int irq1
,
573 int irq2
, void *pdata
, unsigned int periphid
,
574 struct resource
*resbase
)
576 return amba_aphb_device_add(parent
, name
, base
, size
, irq1
, irq2
, pdata
,
577 periphid
, ~0ULL, resbase
);
579 EXPORT_SYMBOL_GPL(amba_ahb_device_add_res
);
582 static void amba_device_initialize(struct amba_device
*dev
, const char *name
)
584 device_initialize(&dev
->dev
);
586 dev_set_name(&dev
->dev
, "%s", name
);
587 dev
->dev
.release
= amba_device_release
;
588 dev
->dev
.bus
= &amba_bustype
;
589 dev
->dev
.dma_mask
= &dev
->dev
.coherent_dma_mask
;
590 dev
->res
.name
= dev_name(&dev
->dev
);
594 * amba_device_alloc - allocate an AMBA device
595 * @name: sysfs name of the AMBA device
596 * @base: base of AMBA device
597 * @size: size of AMBA device
599 * Allocate and initialize an AMBA device structure. Returns %NULL
602 struct amba_device
*amba_device_alloc(const char *name
, resource_size_t base
,
605 struct amba_device
*dev
;
607 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
609 amba_device_initialize(dev
, name
);
610 dev
->res
.start
= base
;
611 dev
->res
.end
= base
+ size
- 1;
612 dev
->res
.flags
= IORESOURCE_MEM
;
617 EXPORT_SYMBOL_GPL(amba_device_alloc
);
620 * amba_device_register - register an AMBA device
621 * @dev: AMBA device to register
622 * @parent: parent memory resource
624 * Setup the AMBA device, reading the cell ID if present.
625 * Claim the resource, and register the AMBA device with
626 * the Linux device manager.
628 int amba_device_register(struct amba_device
*dev
, struct resource
*parent
)
630 amba_device_initialize(dev
, dev
->dev
.init_name
);
631 dev
->dev
.init_name
= NULL
;
633 return amba_device_add(dev
, parent
);
637 * amba_device_put - put an AMBA device
638 * @dev: AMBA device to put
640 void amba_device_put(struct amba_device
*dev
)
642 put_device(&dev
->dev
);
644 EXPORT_SYMBOL_GPL(amba_device_put
);
647 * amba_device_unregister - unregister an AMBA device
648 * @dev: AMBA device to remove
650 * Remove the specified AMBA device from the Linux device
651 * manager. All files associated with this object will be
652 * destroyed, and device drivers notified that the device has
653 * been removed. The AMBA device's resources including
654 * the amba_device structure will be freed once all
655 * references to it have been dropped.
657 void amba_device_unregister(struct amba_device
*dev
)
659 device_unregister(&dev
->dev
);
664 struct amba_device
*dev
;
665 struct device
*parent
;
671 static int amba_find_match(struct device
*dev
, void *data
)
673 struct find_data
*d
= data
;
674 struct amba_device
*pcdev
= to_amba_device(dev
);
677 r
= (pcdev
->periphid
& d
->mask
) == d
->id
;
679 r
&= d
->parent
== dev
->parent
;
681 r
&= strcmp(dev_name(dev
), d
->busid
) == 0;
692 * amba_find_device - locate an AMBA device given a bus id
693 * @busid: bus id for device (or NULL)
694 * @parent: parent device (or NULL)
695 * @id: peripheral ID (or 0)
696 * @mask: peripheral ID mask (or 0)
698 * Return the AMBA device corresponding to the supplied parameters.
699 * If no device matches, returns NULL.
701 * NOTE: When a valid device is found, its refcount is
702 * incremented, and must be decremented before the returned
706 amba_find_device(const char *busid
, struct device
*parent
, unsigned int id
,
709 struct find_data data
;
712 data
.parent
= parent
;
717 bus_for_each_dev(&amba_bustype
, NULL
, &data
, amba_find_match
);
723 * amba_request_regions - request all mem regions associated with device
724 * @dev: amba_device structure for device
725 * @name: name, or NULL to use driver name
727 int amba_request_regions(struct amba_device
*dev
, const char *name
)
733 name
= dev
->dev
.driver
->name
;
735 size
= resource_size(&dev
->res
);
737 if (!request_mem_region(dev
->res
.start
, size
, name
))
744 * amba_release_regions - release mem regions associated with device
745 * @dev: amba_device structure for device
747 * Release regions claimed by a successful call to amba_request_regions.
749 void amba_release_regions(struct amba_device
*dev
)
753 size
= resource_size(&dev
->res
);
754 release_mem_region(dev
->res
.start
, size
);
757 EXPORT_SYMBOL(amba_driver_register
);
758 EXPORT_SYMBOL(amba_driver_unregister
);
759 EXPORT_SYMBOL(amba_device_register
);
760 EXPORT_SYMBOL(amba_device_unregister
);
761 EXPORT_SYMBOL(amba_find_device
);
762 EXPORT_SYMBOL(amba_request_regions
);
763 EXPORT_SYMBOL(amba_release_regions
);