]>
git.ipfire.org Git - thirdparty/linux.git/blob - drivers/amba/bus.c
1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/arch/arm/common/amba.c
5 * Copyright (C) 2003 Deep Blue Solutions Ltd, All Rights Reserved.
7 #include <linux/module.h>
8 #include <linux/init.h>
9 #include <linux/device.h>
10 #include <linux/string.h>
11 #include <linux/slab.h>
14 #include <linux/pm_runtime.h>
15 #include <linux/pm_domain.h>
16 #include <linux/amba/bus.h>
17 #include <linux/sizes.h>
18 #include <linux/limits.h>
19 #include <linux/clk/clk-conf.h>
20 #include <linux/platform_device.h>
21 #include <linux/reset.h>
25 #define to_amba_driver(d) container_of(d, struct amba_driver, drv)
27 /* called on periphid match and class 0x9 coresight device. */
29 amba_cs_uci_id_match(const struct amba_id
*table
, struct amba_device
*dev
)
32 struct amba_cs_uci_id
*uci
;
36 /* no table data or zero mask - return match on periphid */
37 if (!uci
|| (uci
->devarch_mask
== 0))
40 /* test against read devtype and masked devarch value */
41 ret
= (dev
->uci
.devtype
== uci
->devtype
) &&
42 ((dev
->uci
.devarch
& uci
->devarch_mask
) == uci
->devarch
);
46 static const struct amba_id
*
47 amba_lookup(const struct amba_id
*table
, struct amba_device
*dev
)
50 if (((dev
->periphid
& table
->mask
) == table
->id
) &&
51 ((dev
->cid
!= CORESIGHT_CID
) ||
52 (amba_cs_uci_id_match(table
, dev
))))
59 static int amba_match(struct device
*dev
, struct device_driver
*drv
)
61 struct amba_device
*pcdev
= to_amba_device(dev
);
62 struct amba_driver
*pcdrv
= to_amba_driver(drv
);
64 /* When driver_override is set, only bind to the matching driver */
65 if (pcdev
->driver_override
)
66 return !strcmp(pcdev
->driver_override
, drv
->name
);
68 return amba_lookup(pcdrv
->id_table
, pcdev
) != NULL
;
71 static int amba_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
73 struct amba_device
*pcdev
= to_amba_device(dev
);
76 retval
= add_uevent_var(env
, "AMBA_ID=%08x", pcdev
->periphid
);
80 retval
= add_uevent_var(env
, "MODALIAS=amba:d%08X", pcdev
->periphid
);
84 static ssize_t
driver_override_show(struct device
*_dev
,
85 struct device_attribute
*attr
, char *buf
)
87 struct amba_device
*dev
= to_amba_device(_dev
);
91 len
= sprintf(buf
, "%s\n", dev
->driver_override
);
96 static ssize_t
driver_override_store(struct device
*_dev
,
97 struct device_attribute
*attr
,
98 const char *buf
, size_t count
)
100 struct amba_device
*dev
= to_amba_device(_dev
);
101 char *driver_override
, *old
, *cp
;
103 /* We need to keep extra room for a newline */
104 if (count
>= (PAGE_SIZE
- 1))
107 driver_override
= kstrndup(buf
, count
, GFP_KERNEL
);
108 if (!driver_override
)
111 cp
= strchr(driver_override
, '\n');
116 old
= dev
->driver_override
;
117 if (strlen(driver_override
)) {
118 dev
->driver_override
= driver_override
;
120 kfree(driver_override
);
121 dev
->driver_override
= NULL
;
129 static DEVICE_ATTR_RW(driver_override
);
131 #define amba_attr_func(name,fmt,arg...) \
132 static ssize_t name##_show(struct device *_dev, \
133 struct device_attribute *attr, char *buf) \
135 struct amba_device *dev = to_amba_device(_dev); \
136 return sprintf(buf, fmt, arg); \
138 static DEVICE_ATTR_RO(name)
140 amba_attr_func(id
, "%08x\n", dev
->periphid
);
141 amba_attr_func(irq0
, "%u\n", dev
->irq
[0]);
142 amba_attr_func(irq1
, "%u\n", dev
->irq
[1]);
143 amba_attr_func(resource
, "\t%016llx\t%016llx\t%016lx\n",
144 (unsigned long long)dev
->res
.start
, (unsigned long long)dev
->res
.end
,
147 static struct attribute
*amba_dev_attrs
[] = {
149 &dev_attr_resource
.attr
,
150 &dev_attr_driver_override
.attr
,
153 ATTRIBUTE_GROUPS(amba_dev
);
157 * Hooks to provide runtime PM of the pclk (bus clock). It is safe to
158 * enable/disable the bus clock at runtime PM suspend/resume as this
159 * does not result in loss of context.
161 static int amba_pm_runtime_suspend(struct device
*dev
)
163 struct amba_device
*pcdev
= to_amba_device(dev
);
164 int ret
= pm_generic_runtime_suspend(dev
);
166 if (ret
== 0 && dev
->driver
) {
167 if (pm_runtime_is_irq_safe(dev
))
168 clk_disable(pcdev
->pclk
);
170 clk_disable_unprepare(pcdev
->pclk
);
176 static int amba_pm_runtime_resume(struct device
*dev
)
178 struct amba_device
*pcdev
= to_amba_device(dev
);
182 if (pm_runtime_is_irq_safe(dev
))
183 ret
= clk_enable(pcdev
->pclk
);
185 ret
= clk_prepare_enable(pcdev
->pclk
);
186 /* Failure is probably fatal to the system, but... */
191 return pm_generic_runtime_resume(dev
);
193 #endif /* CONFIG_PM */
195 static const struct dev_pm_ops amba_pm
= {
196 .suspend
= pm_generic_suspend
,
197 .resume
= pm_generic_resume
,
198 .freeze
= pm_generic_freeze
,
199 .thaw
= pm_generic_thaw
,
200 .poweroff
= pm_generic_poweroff
,
201 .restore
= pm_generic_restore
,
203 amba_pm_runtime_suspend
,
204 amba_pm_runtime_resume
,
210 * Primecells are part of the Advanced Microcontroller Bus Architecture,
211 * so we call the bus "amba".
212 * DMA configuration for platform and AMBA bus is same. So here we reuse
213 * platform's DMA config routine.
215 struct bus_type amba_bustype
= {
217 .dev_groups
= amba_dev_groups
,
219 .uevent
= amba_uevent
,
220 .dma_configure
= platform_dma_configure
,
223 EXPORT_SYMBOL_GPL(amba_bustype
);
225 static int __init
amba_init(void)
227 return bus_register(&amba_bustype
);
230 postcore_initcall(amba_init
);
232 static int amba_get_enable_pclk(struct amba_device
*pcdev
)
236 pcdev
->pclk
= clk_get(&pcdev
->dev
, "apb_pclk");
237 if (IS_ERR(pcdev
->pclk
))
238 return PTR_ERR(pcdev
->pclk
);
240 ret
= clk_prepare_enable(pcdev
->pclk
);
242 clk_put(pcdev
->pclk
);
247 static void amba_put_disable_pclk(struct amba_device
*pcdev
)
249 clk_disable_unprepare(pcdev
->pclk
);
250 clk_put(pcdev
->pclk
);
254 * These are the device model conversion veneers; they convert the
255 * device model structures to our more specific structures.
257 static int amba_probe(struct device
*dev
)
259 struct amba_device
*pcdev
= to_amba_device(dev
);
260 struct amba_driver
*pcdrv
= to_amba_driver(dev
->driver
);
261 const struct amba_id
*id
= amba_lookup(pcdrv
->id_table
, pcdev
);
265 ret
= of_clk_set_defaults(dev
->of_node
, false);
269 ret
= dev_pm_domain_attach(dev
, true);
273 ret
= amba_get_enable_pclk(pcdev
);
275 dev_pm_domain_detach(dev
, true);
279 pm_runtime_get_noresume(dev
);
280 pm_runtime_set_active(dev
);
281 pm_runtime_enable(dev
);
283 ret
= pcdrv
->probe(pcdev
, id
);
287 pm_runtime_disable(dev
);
288 pm_runtime_set_suspended(dev
);
289 pm_runtime_put_noidle(dev
);
291 amba_put_disable_pclk(pcdev
);
292 dev_pm_domain_detach(dev
, true);
298 static int amba_remove(struct device
*dev
)
300 struct amba_device
*pcdev
= to_amba_device(dev
);
301 struct amba_driver
*drv
= to_amba_driver(dev
->driver
);
304 pm_runtime_get_sync(dev
);
305 ret
= drv
->remove(pcdev
);
306 pm_runtime_put_noidle(dev
);
308 /* Undo the runtime PM settings in amba_probe() */
309 pm_runtime_disable(dev
);
310 pm_runtime_set_suspended(dev
);
311 pm_runtime_put_noidle(dev
);
313 amba_put_disable_pclk(pcdev
);
314 dev_pm_domain_detach(dev
, true);
319 static void amba_shutdown(struct device
*dev
)
321 struct amba_driver
*drv
= to_amba_driver(dev
->driver
);
322 drv
->shutdown(to_amba_device(dev
));
326 * amba_driver_register - register an AMBA device driver
327 * @drv: amba device driver structure
329 * Register an AMBA device driver with the Linux device model
330 * core. If devices pre-exist, the drivers probe function will
333 int amba_driver_register(struct amba_driver
*drv
)
335 drv
->drv
.bus
= &amba_bustype
;
337 #define SETFN(fn) if (drv->fn) drv->drv.fn = amba_##fn
342 return driver_register(&drv
->drv
);
346 * amba_driver_unregister - remove an AMBA device driver
347 * @drv: AMBA device driver structure to remove
349 * Unregister an AMBA device driver from the Linux device
350 * model. The device model will call the drivers remove function
351 * for each device the device driver is currently handling.
353 void amba_driver_unregister(struct amba_driver
*drv
)
355 driver_unregister(&drv
->drv
);
359 static void amba_device_release(struct device
*dev
)
361 struct amba_device
*d
= to_amba_device(dev
);
364 release_resource(&d
->res
);
368 static int amba_device_try_add(struct amba_device
*dev
, struct resource
*parent
)
374 WARN_ON(dev
->irq
[0] == (unsigned int)-1);
375 WARN_ON(dev
->irq
[1] == (unsigned int)-1);
377 ret
= request_resource(parent
, &dev
->res
);
381 /* Hard-coded primecell ID instead of plug-n-play */
382 if (dev
->periphid
!= 0)
386 * Dynamically calculate the size of the resource
387 * and use this for iomap
389 size
= resource_size(&dev
->res
);
390 tmp
= ioremap(dev
->res
.start
, size
);
396 ret
= dev_pm_domain_attach(&dev
->dev
, true);
402 ret
= amba_get_enable_pclk(dev
);
405 struct reset_control
*rstc
;
408 * Find reset control(s) of the amba bus and de-assert them.
410 rstc
= of_reset_control_array_get_optional_shared(dev
->dev
.of_node
);
413 if (ret
!= -EPROBE_DEFER
)
414 dev_err(&dev
->dev
, "can't get reset: %d\n",
418 reset_control_deassert(rstc
);
419 reset_control_put(rstc
);
422 * Read pid and cid based on size of resource
423 * they are located at end of region
425 for (pid
= 0, i
= 0; i
< 4; i
++)
426 pid
|= (readl(tmp
+ size
- 0x20 + 4 * i
) & 255) <<
428 for (cid
= 0, i
= 0; i
< 4; i
++)
429 cid
|= (readl(tmp
+ size
- 0x10 + 4 * i
) & 255) <<
432 if (cid
== CORESIGHT_CID
) {
433 /* set the base to the start of the last 4k block */
434 void __iomem
*csbase
= tmp
+ size
- 4096;
437 readl(csbase
+ UCI_REG_DEVARCH_OFFSET
);
439 readl(csbase
+ UCI_REG_DEVTYPE_OFFSET
) & 0xff;
442 amba_put_disable_pclk(dev
);
444 if (cid
== AMBA_CID
|| cid
== CORESIGHT_CID
) {
454 dev_pm_domain_detach(&dev
->dev
, true);
460 ret
= device_add(&dev
->dev
);
465 ret
= device_create_file(&dev
->dev
, &dev_attr_irq0
);
466 if (ret
== 0 && dev
->irq
[1])
467 ret
= device_create_file(&dev
->dev
, &dev_attr_irq1
);
471 device_unregister(&dev
->dev
);
474 release_resource(&dev
->res
);
479 amba_put_disable_pclk(dev
);
481 dev_pm_domain_detach(&dev
->dev
, true);
486 * Registration of AMBA device require reading its pid and cid registers.
487 * To do this, the device must be turned on (if it is a part of power domain)
488 * and have clocks enabled. However in some cases those resources might not be
489 * yet available. Returning EPROBE_DEFER is not a solution in such case,
490 * because callers don't handle this special error code. Instead such devices
491 * are added to the special list and their registration is retried from
492 * periodic worker, until all resources are available and registration succeeds.
494 struct deferred_device
{
495 struct amba_device
*dev
;
496 struct resource
*parent
;
497 struct list_head node
;
500 static LIST_HEAD(deferred_devices
);
501 static DEFINE_MUTEX(deferred_devices_lock
);
503 static void amba_deferred_retry_func(struct work_struct
*dummy
);
504 static DECLARE_DELAYED_WORK(deferred_retry_work
, amba_deferred_retry_func
);
506 #define DEFERRED_DEVICE_TIMEOUT (msecs_to_jiffies(5 * 1000))
508 static void amba_deferred_retry_func(struct work_struct
*dummy
)
510 struct deferred_device
*ddev
, *tmp
;
512 mutex_lock(&deferred_devices_lock
);
514 list_for_each_entry_safe(ddev
, tmp
, &deferred_devices
, node
) {
515 int ret
= amba_device_try_add(ddev
->dev
, ddev
->parent
);
517 if (ret
== -EPROBE_DEFER
)
520 list_del_init(&ddev
->node
);
524 if (!list_empty(&deferred_devices
))
525 schedule_delayed_work(&deferred_retry_work
,
526 DEFERRED_DEVICE_TIMEOUT
);
528 mutex_unlock(&deferred_devices_lock
);
532 * amba_device_add - add a previously allocated AMBA device structure
533 * @dev: AMBA device allocated by amba_device_alloc
534 * @parent: resource parent for this devices resources
536 * Claim the resource, and read the device cell ID if not already
537 * initialized. Register the AMBA device with the Linux device
540 int amba_device_add(struct amba_device
*dev
, struct resource
*parent
)
542 int ret
= amba_device_try_add(dev
, parent
);
544 if (ret
== -EPROBE_DEFER
) {
545 struct deferred_device
*ddev
;
547 ddev
= kmalloc(sizeof(*ddev
), GFP_KERNEL
);
552 ddev
->parent
= parent
;
555 mutex_lock(&deferred_devices_lock
);
557 if (list_empty(&deferred_devices
))
558 schedule_delayed_work(&deferred_retry_work
,
559 DEFERRED_DEVICE_TIMEOUT
);
560 list_add_tail(&ddev
->node
, &deferred_devices
);
562 mutex_unlock(&deferred_devices_lock
);
566 EXPORT_SYMBOL_GPL(amba_device_add
);
568 static struct amba_device
*
569 amba_aphb_device_add(struct device
*parent
, const char *name
,
570 resource_size_t base
, size_t size
, int irq1
, int irq2
,
571 void *pdata
, unsigned int periphid
, u64 dma_mask
,
572 struct resource
*resbase
)
574 struct amba_device
*dev
;
577 dev
= amba_device_alloc(name
, base
, size
);
579 return ERR_PTR(-ENOMEM
);
581 dev
->dev
.coherent_dma_mask
= dma_mask
;
584 dev
->periphid
= periphid
;
585 dev
->dev
.platform_data
= pdata
;
586 dev
->dev
.parent
= parent
;
588 ret
= amba_device_add(dev
, resbase
);
590 amba_device_put(dev
);
598 amba_apb_device_add(struct device
*parent
, const char *name
,
599 resource_size_t base
, size_t size
, int irq1
, int irq2
,
600 void *pdata
, unsigned int periphid
)
602 return amba_aphb_device_add(parent
, name
, base
, size
, irq1
, irq2
, pdata
,
603 periphid
, 0, &iomem_resource
);
605 EXPORT_SYMBOL_GPL(amba_apb_device_add
);
608 amba_ahb_device_add(struct device
*parent
, const char *name
,
609 resource_size_t base
, size_t size
, int irq1
, int irq2
,
610 void *pdata
, unsigned int periphid
)
612 return amba_aphb_device_add(parent
, name
, base
, size
, irq1
, irq2
, pdata
,
613 periphid
, ~0ULL, &iomem_resource
);
615 EXPORT_SYMBOL_GPL(amba_ahb_device_add
);
618 amba_apb_device_add_res(struct device
*parent
, const char *name
,
619 resource_size_t base
, size_t size
, int irq1
,
620 int irq2
, void *pdata
, unsigned int periphid
,
621 struct resource
*resbase
)
623 return amba_aphb_device_add(parent
, name
, base
, size
, irq1
, irq2
, pdata
,
624 periphid
, 0, resbase
);
626 EXPORT_SYMBOL_GPL(amba_apb_device_add_res
);
629 amba_ahb_device_add_res(struct device
*parent
, const char *name
,
630 resource_size_t base
, size_t size
, int irq1
,
631 int irq2
, void *pdata
, unsigned int periphid
,
632 struct resource
*resbase
)
634 return amba_aphb_device_add(parent
, name
, base
, size
, irq1
, irq2
, pdata
,
635 periphid
, ~0ULL, resbase
);
637 EXPORT_SYMBOL_GPL(amba_ahb_device_add_res
);
640 static void amba_device_initialize(struct amba_device
*dev
, const char *name
)
642 device_initialize(&dev
->dev
);
644 dev_set_name(&dev
->dev
, "%s", name
);
645 dev
->dev
.release
= amba_device_release
;
646 dev
->dev
.bus
= &amba_bustype
;
647 dev
->dev
.dma_mask
= &dev
->dev
.coherent_dma_mask
;
648 dev
->dev
.dma_parms
= &dev
->dma_parms
;
649 dev
->res
.name
= dev_name(&dev
->dev
);
653 * amba_device_alloc - allocate an AMBA device
654 * @name: sysfs name of the AMBA device
655 * @base: base of AMBA device
656 * @size: size of AMBA device
658 * Allocate and initialize an AMBA device structure. Returns %NULL
661 struct amba_device
*amba_device_alloc(const char *name
, resource_size_t base
,
664 struct amba_device
*dev
;
666 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
668 amba_device_initialize(dev
, name
);
669 dev
->res
.start
= base
;
670 dev
->res
.end
= base
+ size
- 1;
671 dev
->res
.flags
= IORESOURCE_MEM
;
676 EXPORT_SYMBOL_GPL(amba_device_alloc
);
679 * amba_device_register - register an AMBA device
680 * @dev: AMBA device to register
681 * @parent: parent memory resource
683 * Setup the AMBA device, reading the cell ID if present.
684 * Claim the resource, and register the AMBA device with
685 * the Linux device manager.
687 int amba_device_register(struct amba_device
*dev
, struct resource
*parent
)
689 amba_device_initialize(dev
, dev
->dev
.init_name
);
690 dev
->dev
.init_name
= NULL
;
692 return amba_device_add(dev
, parent
);
696 * amba_device_put - put an AMBA device
697 * @dev: AMBA device to put
699 void amba_device_put(struct amba_device
*dev
)
701 put_device(&dev
->dev
);
703 EXPORT_SYMBOL_GPL(amba_device_put
);
706 * amba_device_unregister - unregister an AMBA device
707 * @dev: AMBA device to remove
709 * Remove the specified AMBA device from the Linux device
710 * manager. All files associated with this object will be
711 * destroyed, and device drivers notified that the device has
712 * been removed. The AMBA device's resources including
713 * the amba_device structure will be freed once all
714 * references to it have been dropped.
716 void amba_device_unregister(struct amba_device
*dev
)
718 device_unregister(&dev
->dev
);
723 struct amba_device
*dev
;
724 struct device
*parent
;
730 static int amba_find_match(struct device
*dev
, void *data
)
732 struct find_data
*d
= data
;
733 struct amba_device
*pcdev
= to_amba_device(dev
);
736 r
= (pcdev
->periphid
& d
->mask
) == d
->id
;
738 r
&= d
->parent
== dev
->parent
;
740 r
&= strcmp(dev_name(dev
), d
->busid
) == 0;
751 * amba_find_device - locate an AMBA device given a bus id
752 * @busid: bus id for device (or NULL)
753 * @parent: parent device (or NULL)
754 * @id: peripheral ID (or 0)
755 * @mask: peripheral ID mask (or 0)
757 * Return the AMBA device corresponding to the supplied parameters.
758 * If no device matches, returns NULL.
760 * NOTE: When a valid device is found, its refcount is
761 * incremented, and must be decremented before the returned
765 amba_find_device(const char *busid
, struct device
*parent
, unsigned int id
,
768 struct find_data data
;
771 data
.parent
= parent
;
776 bus_for_each_dev(&amba_bustype
, NULL
, &data
, amba_find_match
);
782 * amba_request_regions - request all mem regions associated with device
783 * @dev: amba_device structure for device
784 * @name: name, or NULL to use driver name
786 int amba_request_regions(struct amba_device
*dev
, const char *name
)
792 name
= dev
->dev
.driver
->name
;
794 size
= resource_size(&dev
->res
);
796 if (!request_mem_region(dev
->res
.start
, size
, name
))
803 * amba_release_regions - release mem regions associated with device
804 * @dev: amba_device structure for device
806 * Release regions claimed by a successful call to amba_request_regions.
808 void amba_release_regions(struct amba_device
*dev
)
812 size
= resource_size(&dev
->res
);
813 release_mem_region(dev
->res
.start
, size
);
816 EXPORT_SYMBOL(amba_driver_register
);
817 EXPORT_SYMBOL(amba_driver_unregister
);
818 EXPORT_SYMBOL(amba_device_register
);
819 EXPORT_SYMBOL(amba_device_unregister
);
820 EXPORT_SYMBOL(amba_find_device
);
821 EXPORT_SYMBOL(amba_request_regions
);
822 EXPORT_SYMBOL(amba_release_regions
);