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git.proxmox.com Git - mirror_ubuntu-jammy-kernel.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_get_enable_pclk(struct amba_device
*pcdev
)
63 pcdev
->pclk
= clk_get(&pcdev
->dev
, "apb_pclk");
64 if (IS_ERR(pcdev
->pclk
))
65 return PTR_ERR(pcdev
->pclk
);
67 ret
= clk_prepare_enable(pcdev
->pclk
);
74 static void amba_put_disable_pclk(struct amba_device
*pcdev
)
76 clk_disable_unprepare(pcdev
->pclk
);
81 static ssize_t
driver_override_show(struct device
*_dev
,
82 struct device_attribute
*attr
, char *buf
)
84 struct amba_device
*dev
= to_amba_device(_dev
);
88 len
= sprintf(buf
, "%s\n", dev
->driver_override
);
93 static ssize_t
driver_override_store(struct device
*_dev
,
94 struct device_attribute
*attr
,
95 const char *buf
, size_t count
)
97 struct amba_device
*dev
= to_amba_device(_dev
);
98 char *driver_override
, *old
, *cp
;
100 /* We need to keep extra room for a newline */
101 if (count
>= (PAGE_SIZE
- 1))
104 driver_override
= kstrndup(buf
, count
, GFP_KERNEL
);
105 if (!driver_override
)
108 cp
= strchr(driver_override
, '\n');
113 old
= dev
->driver_override
;
114 if (strlen(driver_override
)) {
115 dev
->driver_override
= driver_override
;
117 kfree(driver_override
);
118 dev
->driver_override
= NULL
;
126 static DEVICE_ATTR_RW(driver_override
);
128 #define amba_attr_func(name,fmt,arg...) \
129 static ssize_t name##_show(struct device *_dev, \
130 struct device_attribute *attr, char *buf) \
132 struct amba_device *dev = to_amba_device(_dev); \
133 return sprintf(buf, fmt, arg); \
135 static DEVICE_ATTR_RO(name)
137 amba_attr_func(id
, "%08x\n", dev
->periphid
);
138 amba_attr_func(irq0
, "%u\n", dev
->irq
[0]);
139 amba_attr_func(irq1
, "%u\n", dev
->irq
[1]);
140 amba_attr_func(resource
, "\t%016llx\t%016llx\t%016lx\n",
141 (unsigned long long)dev
->res
.start
, (unsigned long long)dev
->res
.end
,
144 static struct attribute
*amba_dev_attrs
[] = {
146 &dev_attr_resource
.attr
,
147 &dev_attr_driver_override
.attr
,
150 ATTRIBUTE_GROUPS(amba_dev
);
152 static int amba_match(struct device
*dev
, struct device_driver
*drv
)
154 struct amba_device
*pcdev
= to_amba_device(dev
);
155 struct amba_driver
*pcdrv
= to_amba_driver(drv
);
157 /* When driver_override is set, only bind to the matching driver */
158 if (pcdev
->driver_override
)
159 return !strcmp(pcdev
->driver_override
, drv
->name
);
161 return amba_lookup(pcdrv
->id_table
, pcdev
) != NULL
;
164 static int amba_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
166 struct amba_device
*pcdev
= to_amba_device(dev
);
169 retval
= add_uevent_var(env
, "AMBA_ID=%08x", pcdev
->periphid
);
173 retval
= add_uevent_var(env
, "MODALIAS=amba:d%08X", pcdev
->periphid
);
178 * These are the device model conversion veneers; they convert the
179 * device model structures to our more specific structures.
181 static int amba_probe(struct device
*dev
)
183 struct amba_device
*pcdev
= to_amba_device(dev
);
184 struct amba_driver
*pcdrv
= to_amba_driver(dev
->driver
);
185 const struct amba_id
*id
= amba_lookup(pcdrv
->id_table
, pcdev
);
189 ret
= of_clk_set_defaults(dev
->of_node
, false);
193 ret
= dev_pm_domain_attach(dev
, true);
197 ret
= amba_get_enable_pclk(pcdev
);
199 dev_pm_domain_detach(dev
, true);
203 pm_runtime_get_noresume(dev
);
204 pm_runtime_set_active(dev
);
205 pm_runtime_enable(dev
);
207 ret
= pcdrv
->probe(pcdev
, id
);
211 pm_runtime_disable(dev
);
212 pm_runtime_set_suspended(dev
);
213 pm_runtime_put_noidle(dev
);
215 amba_put_disable_pclk(pcdev
);
216 dev_pm_domain_detach(dev
, true);
222 static void amba_remove(struct device
*dev
)
224 struct amba_device
*pcdev
= to_amba_device(dev
);
225 struct amba_driver
*drv
= to_amba_driver(dev
->driver
);
227 pm_runtime_get_sync(dev
);
230 pm_runtime_put_noidle(dev
);
232 /* Undo the runtime PM settings in amba_probe() */
233 pm_runtime_disable(dev
);
234 pm_runtime_set_suspended(dev
);
235 pm_runtime_put_noidle(dev
);
237 amba_put_disable_pclk(pcdev
);
238 dev_pm_domain_detach(dev
, true);
241 static void amba_shutdown(struct device
*dev
)
243 struct amba_driver
*drv
;
248 drv
= to_amba_driver(dev
->driver
);
250 drv
->shutdown(to_amba_device(dev
));
255 * Hooks to provide runtime PM of the pclk (bus clock). It is safe to
256 * enable/disable the bus clock at runtime PM suspend/resume as this
257 * does not result in loss of context.
259 static int amba_pm_runtime_suspend(struct device
*dev
)
261 struct amba_device
*pcdev
= to_amba_device(dev
);
262 int ret
= pm_generic_runtime_suspend(dev
);
264 if (ret
== 0 && dev
->driver
) {
265 if (pm_runtime_is_irq_safe(dev
))
266 clk_disable(pcdev
->pclk
);
268 clk_disable_unprepare(pcdev
->pclk
);
274 static int amba_pm_runtime_resume(struct device
*dev
)
276 struct amba_device
*pcdev
= to_amba_device(dev
);
280 if (pm_runtime_is_irq_safe(dev
))
281 ret
= clk_enable(pcdev
->pclk
);
283 ret
= clk_prepare_enable(pcdev
->pclk
);
284 /* Failure is probably fatal to the system, but... */
289 return pm_generic_runtime_resume(dev
);
291 #endif /* CONFIG_PM */
293 static const struct dev_pm_ops amba_pm
= {
294 .suspend
= pm_generic_suspend
,
295 .resume
= pm_generic_resume
,
296 .freeze
= pm_generic_freeze
,
297 .thaw
= pm_generic_thaw
,
298 .poweroff
= pm_generic_poweroff
,
299 .restore
= pm_generic_restore
,
301 amba_pm_runtime_suspend
,
302 amba_pm_runtime_resume
,
308 * Primecells are part of the Advanced Microcontroller Bus Architecture,
309 * so we call the bus "amba".
310 * DMA configuration for platform and AMBA bus is same. So here we reuse
311 * platform's DMA config routine.
313 struct bus_type amba_bustype
= {
315 .dev_groups
= amba_dev_groups
,
317 .uevent
= amba_uevent
,
319 .remove
= amba_remove
,
320 .shutdown
= amba_shutdown
,
321 .dma_configure
= platform_dma_configure
,
324 EXPORT_SYMBOL_GPL(amba_bustype
);
326 static int __init
amba_init(void)
328 return bus_register(&amba_bustype
);
331 postcore_initcall(amba_init
);
334 * amba_driver_register - register an AMBA device driver
335 * @drv: amba device driver structure
337 * Register an AMBA device driver with the Linux device model
338 * core. If devices pre-exist, the drivers probe function will
341 int amba_driver_register(struct amba_driver
*drv
)
346 drv
->drv
.bus
= &amba_bustype
;
348 return driver_register(&drv
->drv
);
352 * amba_driver_unregister - remove an AMBA device driver
353 * @drv: AMBA device driver structure to remove
355 * Unregister an AMBA device driver from the Linux device
356 * model. The device model will call the drivers remove function
357 * for each device the device driver is currently handling.
359 void amba_driver_unregister(struct amba_driver
*drv
)
361 driver_unregister(&drv
->drv
);
365 static void amba_device_release(struct device
*dev
)
367 struct amba_device
*d
= to_amba_device(dev
);
370 release_resource(&d
->res
);
374 static int amba_device_try_add(struct amba_device
*dev
, struct resource
*parent
)
380 ret
= request_resource(parent
, &dev
->res
);
384 /* Hard-coded primecell ID instead of plug-n-play */
385 if (dev
->periphid
!= 0)
389 * Dynamically calculate the size of the resource
390 * and use this for iomap
392 size
= resource_size(&dev
->res
);
393 tmp
= ioremap(dev
->res
.start
, size
);
399 ret
= dev_pm_domain_attach(&dev
->dev
, true);
405 ret
= amba_get_enable_pclk(dev
);
408 struct reset_control
*rstc
;
411 * Find reset control(s) of the amba bus and de-assert them.
413 rstc
= of_reset_control_array_get_optional_shared(dev
->dev
.of_node
);
416 if (ret
!= -EPROBE_DEFER
)
417 dev_err(&dev
->dev
, "can't get reset: %d\n",
421 reset_control_deassert(rstc
);
422 reset_control_put(rstc
);
425 * Read pid and cid based on size of resource
426 * they are located at end of region
428 for (pid
= 0, i
= 0; i
< 4; i
++)
429 pid
|= (readl(tmp
+ size
- 0x20 + 4 * i
) & 255) <<
431 for (cid
= 0, i
= 0; i
< 4; i
++)
432 cid
|= (readl(tmp
+ size
- 0x10 + 4 * i
) & 255) <<
435 if (cid
== CORESIGHT_CID
) {
436 /* set the base to the start of the last 4k block */
437 void __iomem
*csbase
= tmp
+ size
- 4096;
440 readl(csbase
+ UCI_REG_DEVARCH_OFFSET
);
442 readl(csbase
+ UCI_REG_DEVTYPE_OFFSET
) & 0xff;
445 amba_put_disable_pclk(dev
);
447 if (cid
== AMBA_CID
|| cid
== CORESIGHT_CID
) {
457 dev_pm_domain_detach(&dev
->dev
, true);
463 ret
= device_add(&dev
->dev
);
468 ret
= device_create_file(&dev
->dev
, &dev_attr_irq0
);
469 if (ret
== 0 && dev
->irq
[1])
470 ret
= device_create_file(&dev
->dev
, &dev_attr_irq1
);
474 device_unregister(&dev
->dev
);
477 release_resource(&dev
->res
);
482 amba_put_disable_pclk(dev
);
484 dev_pm_domain_detach(&dev
->dev
, true);
489 * Registration of AMBA device require reading its pid and cid registers.
490 * To do this, the device must be turned on (if it is a part of power domain)
491 * and have clocks enabled. However in some cases those resources might not be
492 * yet available. Returning EPROBE_DEFER is not a solution in such case,
493 * because callers don't handle this special error code. Instead such devices
494 * are added to the special list and their registration is retried from
495 * periodic worker, until all resources are available and registration succeeds.
497 struct deferred_device
{
498 struct amba_device
*dev
;
499 struct resource
*parent
;
500 struct list_head node
;
503 static LIST_HEAD(deferred_devices
);
504 static DEFINE_MUTEX(deferred_devices_lock
);
506 static void amba_deferred_retry_func(struct work_struct
*dummy
);
507 static DECLARE_DELAYED_WORK(deferred_retry_work
, amba_deferred_retry_func
);
509 #define DEFERRED_DEVICE_TIMEOUT (msecs_to_jiffies(5 * 1000))
511 static int amba_deferred_retry(void)
513 struct deferred_device
*ddev
, *tmp
;
515 mutex_lock(&deferred_devices_lock
);
517 list_for_each_entry_safe(ddev
, tmp
, &deferred_devices
, node
) {
518 int ret
= amba_device_try_add(ddev
->dev
, ddev
->parent
);
520 if (ret
== -EPROBE_DEFER
)
523 list_del_init(&ddev
->node
);
527 mutex_unlock(&deferred_devices_lock
);
531 late_initcall(amba_deferred_retry
);
533 static void amba_deferred_retry_func(struct work_struct
*dummy
)
535 amba_deferred_retry();
537 if (!list_empty(&deferred_devices
))
538 schedule_delayed_work(&deferred_retry_work
,
539 DEFERRED_DEVICE_TIMEOUT
);
543 * amba_device_add - add a previously allocated AMBA device structure
544 * @dev: AMBA device allocated by amba_device_alloc
545 * @parent: resource parent for this devices resources
547 * Claim the resource, and read the device cell ID if not already
548 * initialized. Register the AMBA device with the Linux device
551 int amba_device_add(struct amba_device
*dev
, struct resource
*parent
)
553 int ret
= amba_device_try_add(dev
, parent
);
555 if (ret
== -EPROBE_DEFER
) {
556 struct deferred_device
*ddev
;
558 ddev
= kmalloc(sizeof(*ddev
), GFP_KERNEL
);
563 ddev
->parent
= parent
;
566 mutex_lock(&deferred_devices_lock
);
568 if (list_empty(&deferred_devices
))
569 schedule_delayed_work(&deferred_retry_work
,
570 DEFERRED_DEVICE_TIMEOUT
);
571 list_add_tail(&ddev
->node
, &deferred_devices
);
573 mutex_unlock(&deferred_devices_lock
);
577 EXPORT_SYMBOL_GPL(amba_device_add
);
579 static struct amba_device
*
580 amba_aphb_device_add(struct device
*parent
, const char *name
,
581 resource_size_t base
, size_t size
, int irq1
, int irq2
,
582 void *pdata
, unsigned int periphid
, u64 dma_mask
,
583 struct resource
*resbase
)
585 struct amba_device
*dev
;
588 dev
= amba_device_alloc(name
, base
, size
);
590 return ERR_PTR(-ENOMEM
);
592 dev
->dev
.coherent_dma_mask
= dma_mask
;
595 dev
->periphid
= periphid
;
596 dev
->dev
.platform_data
= pdata
;
597 dev
->dev
.parent
= parent
;
599 ret
= amba_device_add(dev
, resbase
);
601 amba_device_put(dev
);
609 amba_apb_device_add(struct device
*parent
, const char *name
,
610 resource_size_t base
, size_t size
, int irq1
, int irq2
,
611 void *pdata
, unsigned int periphid
)
613 return amba_aphb_device_add(parent
, name
, base
, size
, irq1
, irq2
, pdata
,
614 periphid
, 0, &iomem_resource
);
616 EXPORT_SYMBOL_GPL(amba_apb_device_add
);
619 amba_ahb_device_add(struct device
*parent
, const char *name
,
620 resource_size_t base
, size_t size
, int irq1
, int irq2
,
621 void *pdata
, unsigned int periphid
)
623 return amba_aphb_device_add(parent
, name
, base
, size
, irq1
, irq2
, pdata
,
624 periphid
, ~0ULL, &iomem_resource
);
626 EXPORT_SYMBOL_GPL(amba_ahb_device_add
);
629 amba_apb_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
, 0, resbase
);
637 EXPORT_SYMBOL_GPL(amba_apb_device_add_res
);
640 amba_ahb_device_add_res(struct device
*parent
, const char *name
,
641 resource_size_t base
, size_t size
, int irq1
,
642 int irq2
, void *pdata
, unsigned int periphid
,
643 struct resource
*resbase
)
645 return amba_aphb_device_add(parent
, name
, base
, size
, irq1
, irq2
, pdata
,
646 periphid
, ~0ULL, resbase
);
648 EXPORT_SYMBOL_GPL(amba_ahb_device_add_res
);
651 static void amba_device_initialize(struct amba_device
*dev
, const char *name
)
653 device_initialize(&dev
->dev
);
655 dev_set_name(&dev
->dev
, "%s", name
);
656 dev
->dev
.release
= amba_device_release
;
657 dev
->dev
.bus
= &amba_bustype
;
658 dev
->dev
.dma_mask
= &dev
->dev
.coherent_dma_mask
;
659 dev
->dev
.dma_parms
= &dev
->dma_parms
;
660 dev
->res
.name
= dev_name(&dev
->dev
);
664 * amba_device_alloc - allocate an AMBA device
665 * @name: sysfs name of the AMBA device
666 * @base: base of AMBA device
667 * @size: size of AMBA device
669 * Allocate and initialize an AMBA device structure. Returns %NULL
672 struct amba_device
*amba_device_alloc(const char *name
, resource_size_t base
,
675 struct amba_device
*dev
;
677 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
679 amba_device_initialize(dev
, name
);
680 dev
->res
.start
= base
;
681 dev
->res
.end
= base
+ size
- 1;
682 dev
->res
.flags
= IORESOURCE_MEM
;
687 EXPORT_SYMBOL_GPL(amba_device_alloc
);
690 * amba_device_register - register an AMBA device
691 * @dev: AMBA device to register
692 * @parent: parent memory resource
694 * Setup the AMBA device, reading the cell ID if present.
695 * Claim the resource, and register the AMBA device with
696 * the Linux device manager.
698 int amba_device_register(struct amba_device
*dev
, struct resource
*parent
)
700 amba_device_initialize(dev
, dev
->dev
.init_name
);
701 dev
->dev
.init_name
= NULL
;
703 return amba_device_add(dev
, parent
);
707 * amba_device_put - put an AMBA device
708 * @dev: AMBA device to put
710 void amba_device_put(struct amba_device
*dev
)
712 put_device(&dev
->dev
);
714 EXPORT_SYMBOL_GPL(amba_device_put
);
717 * amba_device_unregister - unregister an AMBA device
718 * @dev: AMBA device to remove
720 * Remove the specified AMBA device from the Linux device
721 * manager. All files associated with this object will be
722 * destroyed, and device drivers notified that the device has
723 * been removed. The AMBA device's resources including
724 * the amba_device structure will be freed once all
725 * references to it have been dropped.
727 void amba_device_unregister(struct amba_device
*dev
)
729 device_unregister(&dev
->dev
);
734 struct amba_device
*dev
;
735 struct device
*parent
;
741 static int amba_find_match(struct device
*dev
, void *data
)
743 struct find_data
*d
= data
;
744 struct amba_device
*pcdev
= to_amba_device(dev
);
747 r
= (pcdev
->periphid
& d
->mask
) == d
->id
;
749 r
&= d
->parent
== dev
->parent
;
751 r
&= strcmp(dev_name(dev
), d
->busid
) == 0;
762 * amba_find_device - locate an AMBA device given a bus id
763 * @busid: bus id for device (or NULL)
764 * @parent: parent device (or NULL)
765 * @id: peripheral ID (or 0)
766 * @mask: peripheral ID mask (or 0)
768 * Return the AMBA device corresponding to the supplied parameters.
769 * If no device matches, returns NULL.
771 * NOTE: When a valid device is found, its refcount is
772 * incremented, and must be decremented before the returned
776 amba_find_device(const char *busid
, struct device
*parent
, unsigned int id
,
779 struct find_data data
;
782 data
.parent
= parent
;
787 bus_for_each_dev(&amba_bustype
, NULL
, &data
, amba_find_match
);
793 * amba_request_regions - request all mem regions associated with device
794 * @dev: amba_device structure for device
795 * @name: name, or NULL to use driver name
797 int amba_request_regions(struct amba_device
*dev
, const char *name
)
803 name
= dev
->dev
.driver
->name
;
805 size
= resource_size(&dev
->res
);
807 if (!request_mem_region(dev
->res
.start
, size
, name
))
814 * amba_release_regions - release mem regions associated with device
815 * @dev: amba_device structure for device
817 * Release regions claimed by a successful call to amba_request_regions.
819 void amba_release_regions(struct amba_device
*dev
)
823 size
= resource_size(&dev
->res
);
824 release_mem_region(dev
->res
.start
, size
);
827 EXPORT_SYMBOL(amba_driver_register
);
828 EXPORT_SYMBOL(amba_driver_unregister
);
829 EXPORT_SYMBOL(amba_device_register
);
830 EXPORT_SYMBOL(amba_device_unregister
);
831 EXPORT_SYMBOL(amba_find_device
);
832 EXPORT_SYMBOL(amba_request_regions
);
833 EXPORT_SYMBOL(amba_release_regions
);