diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/amba/bus.c | 774 |
1 files changed, 774 insertions, 0 deletions
diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c new file mode 100644 index 000000000..e1992f361 --- /dev/null +++ b/drivers/amba/bus.c @@ -0,0 +1,774 @@ +/* + * linux/arch/arm/common/amba.c + * + * Copyright (C) 2003 Deep Blue Solutions Ltd, All Rights Reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#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 <asm/irq.h> + +#define to_amba_driver(d) container_of(d, struct amba_driver, drv) + +static const struct amba_id * +amba_lookup(const struct amba_id *table, struct amba_device *dev) +{ + int ret = 0; + + while (table->mask) { + ret = (dev->periphid & table->mask) == table->id; + if (ret) + break; + table++; + } + + return ret ? table : NULL; +} + +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); + + /* 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 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); + char *driver_override, *old, *cp; + + /* We need to keep extra room for a newline */ + if (count >= (PAGE_SIZE - 1)) + return -EINVAL; + + driver_override = kstrndup(buf, count, GFP_KERNEL); + if (!driver_override) + return -ENOMEM; + + cp = strchr(driver_override, '\n'); + if (cp) + *cp = '\0'; + + device_lock(_dev); + old = dev->driver_override; + if (strlen(driver_override)) { + dev->driver_override = driver_override; + } else { + kfree(driver_override); + dev->driver_override = NULL; + } + device_unlock(_dev); + + kfree(old); + + 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(irq0, "%u\n", dev->irq[0]); +amba_attr_func(irq1, "%u\n", dev->irq[1]); +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); + +#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, + .dma_configure = platform_dma_configure, + .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_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); +} + +/* + * 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_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 int amba_remove(struct device *dev) +{ + struct amba_device *pcdev = to_amba_device(dev); + struct amba_driver *drv = to_amba_driver(dev->driver); + int ret = 0; + + pm_runtime_get_sync(dev); + if (drv->remove) + ret = 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); + + return ret; +} + +static void amba_shutdown(struct device *dev) +{ + struct amba_driver *drv = to_amba_driver(dev->driver); + + if (drv->shutdown) + drv->shutdown(to_amba_device(dev)); +} + +/** + * 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; + drv->drv.probe = amba_probe; + drv->drv.remove = amba_remove; + drv->drv.shutdown = amba_shutdown; + + return driver_register(&drv->drv); +} + +/** + * 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); +} + + +static void amba_device_release(struct device *dev) +{ + struct amba_device *d = to_amba_device(dev); + + if (d->res.parent) + release_resource(&d->res); + kfree(d); +} + +static int amba_device_try_add(struct amba_device *dev, struct resource *parent) +{ + u32 size; + void __iomem *tmp; + int i, ret; + + ret = request_resource(parent, &dev->res); + if (ret) + goto err_out; + + /* Hard-coded primecell ID instead of plug-n-play */ + if (dev->periphid != 0) + goto skip_probe; + + /* + * Dynamically calculate the size of the resource + * and use this for iomap + */ + size = resource_size(&dev->res); + tmp = ioremap(dev->res.start, size); + if (!tmp) { + ret = -ENOMEM; + goto err_release; + } + + ret = dev_pm_domain_attach(&dev->dev, true); + if (ret) { + iounmap(tmp); + goto err_release; + } + + ret = amba_get_enable_pclk(dev); + if (ret == 0) { + u32 pid, cid; + + /* + * 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); + + amba_put_disable_pclk(dev); + + if (cid == AMBA_CID || cid == CORESIGHT_CID) + dev->periphid = pid; + + if (!dev->periphid) + ret = -ENODEV; + } + + iounmap(tmp); + dev_pm_domain_detach(&dev->dev, true); + + if (ret) + goto err_release; + + skip_probe: + ret = device_add(&dev->dev); + if (ret) + goto err_release; + + if (dev->irq[0]) + ret = device_create_file(&dev->dev, &dev_attr_irq0); + if (ret == 0 && dev->irq[1]) + ret = device_create_file(&dev->dev, &dev_attr_irq1); + if (ret == 0) + return ret; + + device_unregister(&dev->dev); + + err_release: + release_resource(&dev->res); + err_out: + return ret; +} + +/* + * Registration of AMBA device require reading its pid and cid registers. + * To do this, the device must be turned on (if it is a part of power domain) + * and have clocks enabled. However in some cases those resources might not be + * yet available. Returning EPROBE_DEFER is not a solution in such case, + * because callers don't handle this special error code. Instead such devices + * are added to the special list and their registration is retried from + * periodic worker, until all resources are available and registration succeeds. + */ +struct deferred_device { + struct amba_device *dev; + struct resource *parent; + struct list_head node; +}; + +static LIST_HEAD(deferred_devices); +static DEFINE_MUTEX(deferred_devices_lock); + +static void amba_deferred_retry_func(struct work_struct *dummy); +static DECLARE_DELAYED_WORK(deferred_retry_work, amba_deferred_retry_func); + +#define DEFERRED_DEVICE_TIMEOUT (msecs_to_jiffies(5 * 1000)) + +static void amba_deferred_retry_func(struct work_struct *dummy) +{ + struct deferred_device *ddev, *tmp; + + mutex_lock(&deferred_devices_lock); + + list_for_each_entry_safe(ddev, tmp, &deferred_devices, node) { + int ret = amba_device_try_add(ddev->dev, ddev->parent); + + if (ret == -EPROBE_DEFER) + continue; + + list_del_init(&ddev->node); + kfree(ddev); + } + + if (!list_empty(&deferred_devices)) + schedule_delayed_work(&deferred_retry_work, + DEFERRED_DEVICE_TIMEOUT); + + mutex_unlock(&deferred_devices_lock); +} + +/** + * 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 = amba_device_try_add(dev, parent); + + if (ret == -EPROBE_DEFER) { + struct deferred_device *ddev; + + ddev = kmalloc(sizeof(*ddev), GFP_KERNEL); + if (!ddev) + return -ENOMEM; + + ddev->dev = dev; + ddev->parent = parent; + ret = 0; + + mutex_lock(&deferred_devices_lock); + + if (list_empty(&deferred_devices)) + schedule_delayed_work(&deferred_retry_work, + DEFERRED_DEVICE_TIMEOUT); + list_add_tail(&ddev->node, &deferred_devices); + + mutex_unlock(&deferred_devices_lock); + } + return ret; +} +EXPORT_SYMBOL_GPL(amba_device_add); + +static struct amba_device * +amba_aphb_device_add(struct device *parent, const char *name, + resource_size_t base, size_t size, int irq1, int irq2, + void *pdata, unsigned int periphid, u64 dma_mask, + struct resource *resbase) +{ + struct amba_device *dev; + int ret; + + dev = amba_device_alloc(name, base, size); + if (!dev) + return ERR_PTR(-ENOMEM); + + dev->dev.coherent_dma_mask = dma_mask; + dev->irq[0] = irq1; + dev->irq[1] = irq2; + dev->periphid = periphid; + dev->dev.platform_data = pdata; + dev->dev.parent = parent; + + ret = amba_device_add(dev, resbase); + if (ret) { + amba_device_put(dev); + return ERR_PTR(ret); + } + + return dev; +} + +struct amba_device * +amba_apb_device_add(struct device *parent, const char *name, + resource_size_t base, size_t size, int irq1, int irq2, + void *pdata, unsigned int periphid) +{ + return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata, + periphid, 0, &iomem_resource); +} +EXPORT_SYMBOL_GPL(amba_apb_device_add); + +struct amba_device * +amba_ahb_device_add(struct device *parent, const char *name, + resource_size_t base, size_t size, int irq1, int irq2, + void *pdata, unsigned int periphid) +{ + return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata, + periphid, ~0ULL, &iomem_resource); +} +EXPORT_SYMBOL_GPL(amba_ahb_device_add); + +struct amba_device * +amba_apb_device_add_res(struct device *parent, const char *name, + resource_size_t base, size_t size, int irq1, + int irq2, void *pdata, unsigned int periphid, + struct resource *resbase) +{ + return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata, + periphid, 0, resbase); +} +EXPORT_SYMBOL_GPL(amba_apb_device_add_res); + +struct amba_device * +amba_ahb_device_add_res(struct device *parent, const char *name, + resource_size_t base, size_t size, int irq1, + int irq2, void *pdata, unsigned int periphid, + struct resource *resbase) +{ + return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata, + periphid, ~0ULL, resbase); +} +EXPORT_SYMBOL_GPL(amba_ahb_device_add_res); + + +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->res.name = dev_name(&dev->dev); +} + +/** + * 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); +} + +/** + * 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); +} + + +struct find_data { + struct amba_device *dev; + struct device *parent; + const char *busid; + unsigned int id; + unsigned int mask; +}; + +static int amba_find_match(struct device *dev, void *data) +{ + struct find_data *d = data; + struct amba_device *pcdev = to_amba_device(dev); + int r; + + r = (pcdev->periphid & d->mask) == d->id; + if (d->parent) + r &= d->parent == dev->parent; + if (d->busid) + r &= strcmp(dev_name(dev), d->busid) == 0; + + if (r) { + get_device(dev); + d->dev = pcdev; + } + + return r; +} + +/** + * amba_find_device - locate an AMBA device given a bus id + * @busid: bus id for device (or NULL) + * @parent: parent device (or NULL) + * @id: peripheral ID (or 0) + * @mask: peripheral ID mask (or 0) + * + * Return the AMBA device corresponding to the supplied parameters. + * If no device matches, returns NULL. + * + * NOTE: When a valid device is found, its refcount is + * incremented, and must be decremented before the returned + * reference. + */ +struct amba_device * +amba_find_device(const char *busid, struct device *parent, unsigned int id, + unsigned int mask) +{ + struct find_data data; + + data.dev = NULL; + data.parent = parent; + data.busid = busid; + data.id = id; + data.mask = mask; + + bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match); + + return data.dev; +} + +/** + * 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; +} + +/** + * 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_driver_register); +EXPORT_SYMBOL(amba_driver_unregister); +EXPORT_SYMBOL(amba_device_register); +EXPORT_SYMBOL(amba_device_unregister); +EXPORT_SYMBOL(amba_find_device); +EXPORT_SYMBOL(amba_request_regions); +EXPORT_SYMBOL(amba_release_regions); |