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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/amba/bus.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/amba/bus.c')
-rw-r--r-- | drivers/amba/bus.c | 702 |
1 files changed, 702 insertions, 0 deletions
diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c new file mode 100644 index 000000000..0aa2d3111 --- /dev/null +++ b/drivers/amba/bus.c @@ -0,0 +1,702 @@ +// 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); |