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- // SPDX-License-Identifier: GPL-2.0-only
- /*
- * linux/arch/arm/common/amba.c
- *
- * Copyright (C) 2003 Deep Blue Solutions Ltd, All Rights Reserved.
- */
- #include <linux/module.h>
- #include <linux/init.h>
- #include <linux/device.h>
- #include <linux/string.h>
- #include <linux/slab.h>
- #include <linux/io.h>
- #include <linux/pm.h>
- #include <linux/pm_runtime.h>
- #include <linux/pm_domain.h>
- #include <linux/amba/bus.h>
- #include <linux/sizes.h>
- #include <linux/limits.h>
- #include <linux/clk/clk-conf.h>
- #include <linux/platform_device.h>
- #include <linux/reset.h>
- #include <linux/of_irq.h>
- #include <linux/of_device.h>
- #include <linux/acpi.h>
- #include <linux/iommu.h>
- #include <linux/dma-map-ops.h>
- #define to_amba_driver(d) container_of(d, struct amba_driver, drv)
- /* called on periphid match and class 0x9 coresight device. */
- static int
- amba_cs_uci_id_match(const struct amba_id *table, struct amba_device *dev)
- {
- int ret = 0;
- struct amba_cs_uci_id *uci;
- uci = table->data;
- /* no table data or zero mask - return match on periphid */
- if (!uci || (uci->devarch_mask == 0))
- return 1;
- /* test against read devtype and masked devarch value */
- ret = (dev->uci.devtype == uci->devtype) &&
- ((dev->uci.devarch & uci->devarch_mask) == uci->devarch);
- return ret;
- }
- static const struct amba_id *
- amba_lookup(const struct amba_id *table, struct amba_device *dev)
- {
- while (table->mask) {
- if (((dev->periphid & table->mask) == table->id) &&
- ((dev->cid != CORESIGHT_CID) ||
- (amba_cs_uci_id_match(table, dev))))
- return table;
- table++;
- }
- return NULL;
- }
- static int amba_get_enable_pclk(struct amba_device *pcdev)
- {
- int ret;
- pcdev->pclk = clk_get(&pcdev->dev, "apb_pclk");
- if (IS_ERR(pcdev->pclk))
- return PTR_ERR(pcdev->pclk);
- ret = clk_prepare_enable(pcdev->pclk);
- if (ret)
- clk_put(pcdev->pclk);
- return ret;
- }
- static void amba_put_disable_pclk(struct amba_device *pcdev)
- {
- clk_disable_unprepare(pcdev->pclk);
- clk_put(pcdev->pclk);
- }
- static ssize_t driver_override_show(struct device *_dev,
- struct device_attribute *attr, char *buf)
- {
- struct amba_device *dev = to_amba_device(_dev);
- ssize_t len;
- device_lock(_dev);
- len = sprintf(buf, "%s\n", dev->driver_override);
- device_unlock(_dev);
- return len;
- }
- static ssize_t driver_override_store(struct device *_dev,
- struct device_attribute *attr,
- const char *buf, size_t count)
- {
- struct amba_device *dev = to_amba_device(_dev);
- int ret;
- ret = driver_set_override(_dev, &dev->driver_override, buf, count);
- if (ret)
- return ret;
- return count;
- }
- static DEVICE_ATTR_RW(driver_override);
- #define amba_attr_func(name,fmt,arg...) \
- static ssize_t name##_show(struct device *_dev, \
- struct device_attribute *attr, char *buf) \
- { \
- struct amba_device *dev = to_amba_device(_dev); \
- return sprintf(buf, fmt, arg); \
- } \
- static DEVICE_ATTR_RO(name)
- amba_attr_func(id, "%08x\n", dev->periphid);
- amba_attr_func(resource, "\t%016llx\t%016llx\t%016lx\n",
- (unsigned long long)dev->res.start, (unsigned long long)dev->res.end,
- dev->res.flags);
- static struct attribute *amba_dev_attrs[] = {
- &dev_attr_id.attr,
- &dev_attr_resource.attr,
- &dev_attr_driver_override.attr,
- NULL,
- };
- ATTRIBUTE_GROUPS(amba_dev);
- static int amba_read_periphid(struct amba_device *dev)
- {
- struct reset_control *rstc;
- u32 size, pid, cid;
- void __iomem *tmp;
- int i, ret;
- ret = dev_pm_domain_attach(&dev->dev, true);
- if (ret) {
- dev_dbg(&dev->dev, "can't get PM domain: %d\n", ret);
- goto err_out;
- }
- ret = amba_get_enable_pclk(dev);
- if (ret) {
- dev_dbg(&dev->dev, "can't get pclk: %d\n", ret);
- goto err_pm;
- }
- /*
- * Find reset control(s) of the amba bus and de-assert them.
- */
- rstc = of_reset_control_array_get_optional_shared(dev->dev.of_node);
- if (IS_ERR(rstc)) {
- ret = PTR_ERR(rstc);
- if (ret != -EPROBE_DEFER)
- dev_err(&dev->dev, "can't get reset: %d\n", ret);
- goto err_clk;
- }
- reset_control_deassert(rstc);
- reset_control_put(rstc);
- size = resource_size(&dev->res);
- tmp = ioremap(dev->res.start, size);
- if (!tmp) {
- ret = -ENOMEM;
- goto err_clk;
- }
- /*
- * Read pid and cid based on size of resource
- * they are located at end of region
- */
- for (pid = 0, i = 0; i < 4; i++)
- pid |= (readl(tmp + size - 0x20 + 4 * i) & 255) << (i * 8);
- for (cid = 0, i = 0; i < 4; i++)
- cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) << (i * 8);
- if (cid == CORESIGHT_CID) {
- /* set the base to the start of the last 4k block */
- void __iomem *csbase = tmp + size - 4096;
- dev->uci.devarch = readl(csbase + UCI_REG_DEVARCH_OFFSET);
- dev->uci.devtype = readl(csbase + UCI_REG_DEVTYPE_OFFSET) & 0xff;
- }
- if (cid == AMBA_CID || cid == CORESIGHT_CID) {
- dev->periphid = pid;
- dev->cid = cid;
- }
- if (!dev->periphid)
- ret = -ENODEV;
- iounmap(tmp);
- err_clk:
- amba_put_disable_pclk(dev);
- err_pm:
- dev_pm_domain_detach(&dev->dev, true);
- err_out:
- return ret;
- }
- static int amba_match(struct device *dev, struct device_driver *drv)
- {
- struct amba_device *pcdev = to_amba_device(dev);
- struct amba_driver *pcdrv = to_amba_driver(drv);
- mutex_lock(&pcdev->periphid_lock);
- if (!pcdev->periphid) {
- int ret = amba_read_periphid(pcdev);
- /*
- * Returning any error other than -EPROBE_DEFER from bus match
- * can cause driver registration failure. So, if there's a
- * permanent failure in reading pid and cid, simply map it to
- * -EPROBE_DEFER.
- */
- if (ret) {
- mutex_unlock(&pcdev->periphid_lock);
- return -EPROBE_DEFER;
- }
- dev_set_uevent_suppress(dev, false);
- kobject_uevent(&dev->kobj, KOBJ_ADD);
- }
- mutex_unlock(&pcdev->periphid_lock);
- /* When driver_override is set, only bind to the matching driver */
- if (pcdev->driver_override)
- return !strcmp(pcdev->driver_override, drv->name);
- return amba_lookup(pcdrv->id_table, pcdev) != NULL;
- }
- static int amba_uevent(struct device *dev, struct kobj_uevent_env *env)
- {
- struct amba_device *pcdev = to_amba_device(dev);
- int retval = 0;
- retval = add_uevent_var(env, "AMBA_ID=%08x", pcdev->periphid);
- if (retval)
- return retval;
- retval = add_uevent_var(env, "MODALIAS=amba:d%08X", pcdev->periphid);
- return retval;
- }
- static int of_amba_device_decode_irq(struct amba_device *dev)
- {
- struct device_node *node = dev->dev.of_node;
- int i, irq = 0;
- if (IS_ENABLED(CONFIG_OF_IRQ) && node) {
- /* Decode the IRQs and address ranges */
- for (i = 0; i < AMBA_NR_IRQS; i++) {
- irq = of_irq_get(node, i);
- if (irq < 0) {
- if (irq == -EPROBE_DEFER)
- return irq;
- irq = 0;
- }
- dev->irq[i] = irq;
- }
- }
- return 0;
- }
- /*
- * These are the device model conversion veneers; they convert the
- * device model structures to our more specific structures.
- */
- static int amba_probe(struct device *dev)
- {
- struct amba_device *pcdev = to_amba_device(dev);
- struct amba_driver *pcdrv = to_amba_driver(dev->driver);
- const struct amba_id *id = amba_lookup(pcdrv->id_table, pcdev);
- int ret;
- do {
- ret = of_amba_device_decode_irq(pcdev);
- if (ret)
- break;
- ret = of_clk_set_defaults(dev->of_node, false);
- if (ret < 0)
- break;
- ret = dev_pm_domain_attach(dev, true);
- if (ret)
- break;
- ret = amba_get_enable_pclk(pcdev);
- if (ret) {
- dev_pm_domain_detach(dev, true);
- break;
- }
- pm_runtime_get_noresume(dev);
- pm_runtime_set_active(dev);
- pm_runtime_enable(dev);
- ret = pcdrv->probe(pcdev, id);
- if (ret == 0)
- break;
- pm_runtime_disable(dev);
- pm_runtime_set_suspended(dev);
- pm_runtime_put_noidle(dev);
- amba_put_disable_pclk(pcdev);
- dev_pm_domain_detach(dev, true);
- } while (0);
- return ret;
- }
- static void amba_remove(struct device *dev)
- {
- struct amba_device *pcdev = to_amba_device(dev);
- struct amba_driver *drv = to_amba_driver(dev->driver);
- pm_runtime_get_sync(dev);
- if (drv->remove)
- drv->remove(pcdev);
- pm_runtime_put_noidle(dev);
- /* Undo the runtime PM settings in amba_probe() */
- pm_runtime_disable(dev);
- pm_runtime_set_suspended(dev);
- pm_runtime_put_noidle(dev);
- amba_put_disable_pclk(pcdev);
- dev_pm_domain_detach(dev, true);
- }
- static void amba_shutdown(struct device *dev)
- {
- struct amba_driver *drv;
- if (!dev->driver)
- return;
- drv = to_amba_driver(dev->driver);
- if (drv->shutdown)
- drv->shutdown(to_amba_device(dev));
- }
- static int amba_dma_configure(struct device *dev)
- {
- struct amba_driver *drv = to_amba_driver(dev->driver);
- enum dev_dma_attr attr;
- int ret = 0;
- if (dev->of_node) {
- ret = of_dma_configure(dev, dev->of_node, true);
- } else if (has_acpi_companion(dev)) {
- attr = acpi_get_dma_attr(to_acpi_device_node(dev->fwnode));
- ret = acpi_dma_configure(dev, attr);
- }
- if (!ret && !drv->driver_managed_dma) {
- ret = iommu_device_use_default_domain(dev);
- if (ret)
- arch_teardown_dma_ops(dev);
- }
- return ret;
- }
- static void amba_dma_cleanup(struct device *dev)
- {
- struct amba_driver *drv = to_amba_driver(dev->driver);
- if (!drv->driver_managed_dma)
- iommu_device_unuse_default_domain(dev);
- }
- #ifdef CONFIG_PM
- /*
- * Hooks to provide runtime PM of the pclk (bus clock). It is safe to
- * enable/disable the bus clock at runtime PM suspend/resume as this
- * does not result in loss of context.
- */
- static int amba_pm_runtime_suspend(struct device *dev)
- {
- struct amba_device *pcdev = to_amba_device(dev);
- int ret = pm_generic_runtime_suspend(dev);
- if (ret == 0 && dev->driver) {
- if (pm_runtime_is_irq_safe(dev))
- clk_disable(pcdev->pclk);
- else
- clk_disable_unprepare(pcdev->pclk);
- }
- return ret;
- }
- static int amba_pm_runtime_resume(struct device *dev)
- {
- struct amba_device *pcdev = to_amba_device(dev);
- int ret;
- if (dev->driver) {
- if (pm_runtime_is_irq_safe(dev))
- ret = clk_enable(pcdev->pclk);
- else
- ret = clk_prepare_enable(pcdev->pclk);
- /* Failure is probably fatal to the system, but... */
- if (ret)
- return ret;
- }
- return pm_generic_runtime_resume(dev);
- }
- #endif /* CONFIG_PM */
- static const struct dev_pm_ops amba_pm = {
- .suspend = pm_generic_suspend,
- .resume = pm_generic_resume,
- .freeze = pm_generic_freeze,
- .thaw = pm_generic_thaw,
- .poweroff = pm_generic_poweroff,
- .restore = pm_generic_restore,
- SET_RUNTIME_PM_OPS(
- amba_pm_runtime_suspend,
- amba_pm_runtime_resume,
- NULL
- )
- };
- /*
- * Primecells are part of the Advanced Microcontroller Bus Architecture,
- * so we call the bus "amba".
- * DMA configuration for platform and AMBA bus is same. So here we reuse
- * platform's DMA config routine.
- */
- struct bus_type amba_bustype = {
- .name = "amba",
- .dev_groups = amba_dev_groups,
- .match = amba_match,
- .uevent = amba_uevent,
- .probe = amba_probe,
- .remove = amba_remove,
- .shutdown = amba_shutdown,
- .dma_configure = amba_dma_configure,
- .dma_cleanup = amba_dma_cleanup,
- .pm = &amba_pm,
- };
- EXPORT_SYMBOL_GPL(amba_bustype);
- static int __init amba_init(void)
- {
- return bus_register(&amba_bustype);
- }
- postcore_initcall(amba_init);
- static int amba_proxy_probe(struct amba_device *adev,
- const struct amba_id *id)
- {
- WARN(1, "Stub driver should never match any device.\n");
- return -ENODEV;
- }
- static const struct amba_id amba_stub_drv_ids[] = {
- { 0, 0 },
- };
- static struct amba_driver amba_proxy_drv = {
- .drv = {
- .name = "amba-proxy",
- },
- .probe = amba_proxy_probe,
- .id_table = amba_stub_drv_ids,
- };
- static int __init amba_stub_drv_init(void)
- {
- if (!IS_ENABLED(CONFIG_MODULES))
- return 0;
- /*
- * The amba_match() function will get called only if there is at least
- * one amba driver registered. If all amba drivers are modules and are
- * only loaded based on uevents, then we'll hit a chicken-and-egg
- * situation where amba_match() is waiting on drivers and drivers are
- * waiting on amba_match(). So, register a stub driver to make sure
- * amba_match() is called even if no amba driver has been registered.
- */
- return amba_driver_register(&amba_proxy_drv);
- }
- late_initcall_sync(amba_stub_drv_init);
- /**
- * amba_driver_register - register an AMBA device driver
- * @drv: amba device driver structure
- *
- * Register an AMBA device driver with the Linux device model
- * core. If devices pre-exist, the drivers probe function will
- * be called.
- */
- int amba_driver_register(struct amba_driver *drv)
- {
- if (!drv->probe)
- return -EINVAL;
- drv->drv.bus = &amba_bustype;
- return driver_register(&drv->drv);
- }
- EXPORT_SYMBOL(amba_driver_register);
- /**
- * amba_driver_unregister - remove an AMBA device driver
- * @drv: AMBA device driver structure to remove
- *
- * Unregister an AMBA device driver from the Linux device
- * model. The device model will call the drivers remove function
- * for each device the device driver is currently handling.
- */
- void amba_driver_unregister(struct amba_driver *drv)
- {
- driver_unregister(&drv->drv);
- }
- EXPORT_SYMBOL(amba_driver_unregister);
- static void amba_device_release(struct device *dev)
- {
- struct amba_device *d = to_amba_device(dev);
- of_node_put(d->dev.of_node);
- if (d->res.parent)
- release_resource(&d->res);
- mutex_destroy(&d->periphid_lock);
- kfree(d);
- }
- /**
- * amba_device_add - add a previously allocated AMBA device structure
- * @dev: AMBA device allocated by amba_device_alloc
- * @parent: resource parent for this devices resources
- *
- * Claim the resource, and read the device cell ID if not already
- * initialized. Register the AMBA device with the Linux device
- * manager.
- */
- int amba_device_add(struct amba_device *dev, struct resource *parent)
- {
- int ret;
- ret = request_resource(parent, &dev->res);
- if (ret)
- return ret;
- /* If primecell ID isn't hard-coded, figure it out */
- if (!dev->periphid) {
- /*
- * AMBA device uevents require reading its pid and cid
- * registers. To do this, the device must be on, clocked and
- * out of reset. However in some cases those resources might
- * not yet be available. If that's the case, we suppress the
- * generation of uevents until we can read the pid and cid
- * registers. See also amba_match().
- */
- if (amba_read_periphid(dev))
- dev_set_uevent_suppress(&dev->dev, true);
- }
- ret = device_add(&dev->dev);
- if (ret)
- release_resource(&dev->res);
- return ret;
- }
- EXPORT_SYMBOL_GPL(amba_device_add);
- static void amba_device_initialize(struct amba_device *dev, const char *name)
- {
- device_initialize(&dev->dev);
- if (name)
- dev_set_name(&dev->dev, "%s", name);
- dev->dev.release = amba_device_release;
- dev->dev.bus = &amba_bustype;
- dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
- dev->dev.dma_parms = &dev->dma_parms;
- dev->res.name = dev_name(&dev->dev);
- mutex_init(&dev->periphid_lock);
- }
- /**
- * amba_device_alloc - allocate an AMBA device
- * @name: sysfs name of the AMBA device
- * @base: base of AMBA device
- * @size: size of AMBA device
- *
- * Allocate and initialize an AMBA device structure. Returns %NULL
- * on failure.
- */
- struct amba_device *amba_device_alloc(const char *name, resource_size_t base,
- size_t size)
- {
- struct amba_device *dev;
- dev = kzalloc(sizeof(*dev), GFP_KERNEL);
- if (dev) {
- amba_device_initialize(dev, name);
- dev->res.start = base;
- dev->res.end = base + size - 1;
- dev->res.flags = IORESOURCE_MEM;
- }
- return dev;
- }
- EXPORT_SYMBOL_GPL(amba_device_alloc);
- /**
- * amba_device_register - register an AMBA device
- * @dev: AMBA device to register
- * @parent: parent memory resource
- *
- * Setup the AMBA device, reading the cell ID if present.
- * Claim the resource, and register the AMBA device with
- * the Linux device manager.
- */
- int amba_device_register(struct amba_device *dev, struct resource *parent)
- {
- amba_device_initialize(dev, dev->dev.init_name);
- dev->dev.init_name = NULL;
- return amba_device_add(dev, parent);
- }
- EXPORT_SYMBOL(amba_device_register);
- /**
- * amba_device_put - put an AMBA device
- * @dev: AMBA device to put
- */
- void amba_device_put(struct amba_device *dev)
- {
- put_device(&dev->dev);
- }
- EXPORT_SYMBOL_GPL(amba_device_put);
- /**
- * amba_device_unregister - unregister an AMBA device
- * @dev: AMBA device to remove
- *
- * Remove the specified AMBA device from the Linux device
- * manager. All files associated with this object will be
- * destroyed, and device drivers notified that the device has
- * been removed. The AMBA device's resources including
- * the amba_device structure will be freed once all
- * references to it have been dropped.
- */
- void amba_device_unregister(struct amba_device *dev)
- {
- device_unregister(&dev->dev);
- }
- EXPORT_SYMBOL(amba_device_unregister);
- /**
- * amba_request_regions - request all mem regions associated with device
- * @dev: amba_device structure for device
- * @name: name, or NULL to use driver name
- */
- int amba_request_regions(struct amba_device *dev, const char *name)
- {
- int ret = 0;
- u32 size;
- if (!name)
- name = dev->dev.driver->name;
- size = resource_size(&dev->res);
- if (!request_mem_region(dev->res.start, size, name))
- ret = -EBUSY;
- return ret;
- }
- EXPORT_SYMBOL(amba_request_regions);
- /**
- * amba_release_regions - release mem regions associated with device
- * @dev: amba_device structure for device
- *
- * Release regions claimed by a successful call to amba_request_regions.
- */
- void amba_release_regions(struct amba_device *dev)
- {
- u32 size;
- size = resource_size(&dev->res);
- release_mem_region(dev->res.start, size);
- }
- EXPORT_SYMBOL(amba_release_regions);
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