diff options
Diffstat (limited to 'drivers/amba')
| -rw-r--r-- | drivers/amba/Makefile | 2 | ||||
| -rw-r--r-- | drivers/amba/bus.c | 359 |
2 files changed, 361 insertions, 0 deletions
diff --git a/drivers/amba/Makefile b/drivers/amba/Makefile new file mode 100644 index 000000000000..40fe74097be2 --- /dev/null +++ b/drivers/amba/Makefile @@ -0,0 +1,2 @@ +obj-y += bus.o + diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c new file mode 100644 index 000000000000..1bbdd1693d57 --- /dev/null +++ b/drivers/amba/bus.c @@ -0,0 +1,359 @@ +/* + * 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/amba/bus.h> + +#include <asm/io.h> +#include <asm/irq.h> +#include <asm/sizes.h> + +#define to_amba_device(d) container_of(d, struct amba_device, dev) +#define to_amba_driver(d) container_of(d, struct amba_driver, drv) + +static struct amba_id * +amba_lookup(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); + + return amba_lookup(pcdrv->id_table, pcdev) != NULL; +} + +#ifdef CONFIG_HOTPLUG +static int amba_uevent(struct device *dev, char **envp, int nr_env, char *buf, int bufsz) +{ + struct amba_device *pcdev = to_amba_device(dev); + + if (nr_env < 2) + return -ENOMEM; + + snprintf(buf, bufsz, "AMBA_ID=%08x", pcdev->periphid); + *envp++ = buf; + *envp++ = NULL; + return 0; +} +#else +#define amba_uevent NULL +#endif + +static int amba_suspend(struct device *dev, pm_message_t state) +{ + struct amba_driver *drv = to_amba_driver(dev->driver); + int ret = 0; + + if (dev->driver && drv->suspend) + ret = drv->suspend(to_amba_device(dev), state); + return ret; +} + +static int amba_resume(struct device *dev) +{ + struct amba_driver *drv = to_amba_driver(dev->driver); + int ret = 0; + + if (dev->driver && drv->resume) + ret = drv->resume(to_amba_device(dev)); + return ret; +} + +/* + * Primecells are part of the Advanced Microcontroller Bus Architecture, + * so we call the bus "amba". + */ +static struct bus_type amba_bustype = { + .name = "amba", + .match = amba_match, + .uevent = amba_uevent, + .suspend = amba_suspend, + .resume = amba_resume, +}; + +static int __init amba_init(void) +{ + return bus_register(&amba_bustype); +} + +postcore_initcall(amba_init); + +/* + * 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); + struct amba_id *id; + + id = amba_lookup(pcdrv->id_table, pcdev); + + return pcdrv->probe(pcdev, id); +} + +static int amba_remove(struct device *dev) +{ + struct amba_driver *drv = to_amba_driver(dev->driver); + return drv->remove(to_amba_device(dev)); +} + +static void amba_shutdown(struct device *dev) +{ + struct amba_driver *drv = to_amba_driver(dev->driver); + 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) +{ + drv->drv.bus = &amba_bustype; + +#define SETFN(fn) if (drv->fn) drv->drv.fn = amba_##fn + SETFN(probe); + SETFN(remove); + SETFN(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); +} + +#define amba_attr(name,fmt,arg...) \ +static ssize_t show_##name(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(name, S_IRUGO, show_##name, NULL) + +amba_attr(id, "%08x\n", dev->periphid); +amba_attr(irq0, "%u\n", dev->irq[0]); +amba_attr(irq1, "%u\n", dev->irq[1]); +amba_attr(resource, "\t%08lx\t%08lx\t%08lx\n", + dev->res.start, dev->res.end, dev->res.flags); + +/** + * 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) +{ + u32 pid, cid; + void __iomem *tmp; + int i, ret; + + dev->dev.release = amba_device_release; + dev->dev.bus = &amba_bustype; + dev->dev.dma_mask = &dev->dma_mask; + dev->res.name = dev->dev.bus_id; + + if (!dev->dev.coherent_dma_mask && dev->dma_mask) + dev_warn(&dev->dev, "coherent dma mask is unset\n"); + + ret = request_resource(parent, &dev->res); + if (ret == 0) { + tmp = ioremap(dev->res.start, SZ_4K); + if (!tmp) { + ret = -ENOMEM; + goto out; + } + + for (pid = 0, i = 0; i < 4; i++) + pid |= (readl(tmp + 0xfe0 + 4 * i) & 255) << (i * 8); + for (cid = 0, i = 0; i < 4; i++) + cid |= (readl(tmp + 0xff0 + 4 * i) & 255) << (i * 8); + + iounmap(tmp); + + if (cid == 0xb105f00d) + dev->periphid = pid; + + if (dev->periphid) + ret = device_register(&dev->dev); + else + ret = -ENODEV; + + if (ret == 0) { + device_create_file(&dev->dev, &dev_attr_id); + if (dev->irq[0] != NO_IRQ) + device_create_file(&dev->dev, &dev_attr_irq0); + if (dev->irq[1] != NO_IRQ) + device_create_file(&dev->dev, &dev_attr_irq1); + device_create_file(&dev->dev, &dev_attr_resource); + } else { + out: + release_resource(&dev->res); + } + } + return ret; +} + +/** + * 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->bus_id, 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; + + if (!name) + name = dev->dev.driver->name; + + if (!request_mem_region(dev->res.start, SZ_4K, name)) + ret = -EBUSY; + + return ret; +} + +/** + * amba_release_regions - release mem regions assoicated 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) +{ + release_mem_region(dev->res.start, SZ_4K); +} + +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); |