/* * MEN Chameleon Bus. * * Copyright (C) 2013 MEN Mikroelektronik GmbH (www.men.de) * Author: Johannes Thumshirn <johannes.thumshirn@men.de> * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the Free * Software Foundation; version 2 of the License. */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/types.h> #include <linux/idr.h> #include <linux/mcb.h> static DEFINE_IDA(mcb_ida); static const struct mcb_device_id *mcb_match_id(const struct mcb_device_id *ids, struct mcb_device *dev) { if (ids) { while (ids->device) { if (ids->device == dev->id) return ids; ids++; } } return NULL; } static int mcb_match(struct device *dev, struct device_driver *drv) { struct mcb_driver *mdrv = to_mcb_driver(drv); struct mcb_device *mdev = to_mcb_device(dev); const struct mcb_device_id *found_id; found_id = mcb_match_id(mdrv->id_table, mdev); if (found_id) return 1; return 0; } static int mcb_uevent(struct device *dev, struct kobj_uevent_env *env) { struct mcb_device *mdev = to_mcb_device(dev); int ret; ret = add_uevent_var(env, "MODALIAS=mcb:16z%03d", mdev->id); if (ret) return -ENOMEM; return 0; } static int mcb_probe(struct device *dev) { struct mcb_driver *mdrv = to_mcb_driver(dev->driver); struct mcb_device *mdev = to_mcb_device(dev); const struct mcb_device_id *found_id; found_id = mcb_match_id(mdrv->id_table, mdev); if (!found_id) return -ENODEV; return mdrv->probe(mdev, found_id); } static int mcb_remove(struct device *dev) { struct mcb_driver *mdrv = to_mcb_driver(dev->driver); struct mcb_device *mdev = to_mcb_device(dev); mdrv->remove(mdev); put_device(&mdev->dev); return 0; } static void mcb_shutdown(struct device *dev) { struct mcb_device *mdev = to_mcb_device(dev); struct mcb_driver *mdrv = mdev->driver; if (mdrv && mdrv->shutdown) mdrv->shutdown(mdev); } static struct bus_type mcb_bus_type = { .name = "mcb", .match = mcb_match, .uevent = mcb_uevent, .probe = mcb_probe, .remove = mcb_remove, .shutdown = mcb_shutdown, }; /** * __mcb_register_driver() - Register a @mcb_driver at the system * @drv: The @mcb_driver * @owner: The @mcb_driver's module * @mod_name: The name of the @mcb_driver's module * * Register a @mcb_driver at the system. Perform some sanity checks, if * the .probe and .remove methods are provided by the driver. */ int __mcb_register_driver(struct mcb_driver *drv, struct module *owner, const char *mod_name) { if (!drv->probe || !drv->remove) return -EINVAL; drv->driver.owner = owner; drv->driver.bus = &mcb_bus_type; drv->driver.mod_name = mod_name; return driver_register(&drv->driver); } EXPORT_SYMBOL_GPL(__mcb_register_driver); /** * mcb_unregister_driver() - Unregister a @mcb_driver from the system * @drv: The @mcb_driver * * Unregister a @mcb_driver from the system. */ void mcb_unregister_driver(struct mcb_driver *drv) { driver_unregister(&drv->driver); } EXPORT_SYMBOL_GPL(mcb_unregister_driver); static void mcb_release_dev(struct device *dev) { struct mcb_device *mdev = to_mcb_device(dev); mcb_bus_put(mdev->bus); kfree(mdev); } /** * mcb_device_register() - Register a mcb_device * @bus: The @mcb_bus of the device * @dev: The @mcb_device * * Register a specific @mcb_device at a @mcb_bus and the system itself. */ int mcb_device_register(struct mcb_bus *bus, struct mcb_device *dev) { int ret; int device_id; device_initialize(&dev->dev); dev->dev.bus = &mcb_bus_type; dev->dev.parent = bus->dev.parent; dev->dev.release = mcb_release_dev; device_id = dev->id; dev_set_name(&dev->dev, "mcb%d-16z%03d-%d:%d:%d", bus->bus_nr, device_id, dev->inst, dev->group, dev->var); ret = device_add(&dev->dev); if (ret < 0) { pr_err("Failed registering device 16z%03d on bus mcb%d (%d)\n", device_id, bus->bus_nr, ret); goto out; } return 0; out: return ret; } EXPORT_SYMBOL_GPL(mcb_device_register); /** * mcb_alloc_bus() - Allocate a new @mcb_bus * * Allocate a new @mcb_bus. */ struct mcb_bus *mcb_alloc_bus(struct device *carrier) { struct mcb_bus *bus; int bus_nr; bus = kzalloc(sizeof(struct mcb_bus), GFP_KERNEL); if (!bus) return ERR_PTR(-ENOMEM); bus_nr = ida_simple_get(&mcb_ida, 0, 0, GFP_KERNEL); if (bus_nr < 0) { kfree(bus); return ERR_PTR(bus_nr); } INIT_LIST_HEAD(&bus->children); bus->bus_nr = bus_nr; bus->carrier = carrier; return bus; } EXPORT_SYMBOL_GPL(mcb_alloc_bus); static int __mcb_devices_unregister(struct device *dev, void *data) { device_unregister(dev); return 0; } static void mcb_devices_unregister(struct mcb_bus *bus) { bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_devices_unregister); } /** * mcb_release_bus() - Free a @mcb_bus * @bus: The @mcb_bus to release * * Release an allocated @mcb_bus from the system. */ void mcb_release_bus(struct mcb_bus *bus) { mcb_devices_unregister(bus); ida_simple_remove(&mcb_ida, bus->bus_nr); kfree(bus); } EXPORT_SYMBOL_GPL(mcb_release_bus); /** * mcb_bus_put() - Increment refcnt * @bus: The @mcb_bus * * Get a @mcb_bus' ref */ struct mcb_bus *mcb_bus_get(struct mcb_bus *bus) { if (bus) get_device(&bus->dev); return bus; } EXPORT_SYMBOL_GPL(mcb_bus_get); /** * mcb_bus_put() - Decrement refcnt * @bus: The @mcb_bus * * Release a @mcb_bus' ref */ void mcb_bus_put(struct mcb_bus *bus) { if (bus) put_device(&bus->dev); } EXPORT_SYMBOL_GPL(mcb_bus_put); /** * mcb_alloc_dev() - Allocate a device * @bus: The @mcb_bus the device is part of * * Allocate a @mcb_device and add bus. */ struct mcb_device *mcb_alloc_dev(struct mcb_bus *bus) { struct mcb_device *dev; dev = kzalloc(sizeof(struct mcb_device), GFP_KERNEL); if (!dev) return NULL; INIT_LIST_HEAD(&dev->bus_list); dev->bus = bus; return dev; } EXPORT_SYMBOL_GPL(mcb_alloc_dev); /** * mcb_free_dev() - Free @mcb_device * @dev: The device to free * * Free a @mcb_device */ void mcb_free_dev(struct mcb_device *dev) { kfree(dev); } EXPORT_SYMBOL_GPL(mcb_free_dev); static int __mcb_bus_add_devices(struct device *dev, void *data) { struct mcb_device *mdev = to_mcb_device(dev); int retval; if (mdev->is_added) return 0; retval = device_attach(dev); if (retval < 0) dev_err(dev, "Error adding device (%d)\n", retval); mdev->is_added = true; return 0; } static int __mcb_bus_add_child(struct device *dev, void *data) { struct mcb_device *mdev = to_mcb_device(dev); struct mcb_bus *child; BUG_ON(!mdev->is_added); child = mdev->subordinate; if (child) mcb_bus_add_devices(child); return 0; } /** * mcb_bus_add_devices() - Add devices in the bus' internal device list * @bus: The @mcb_bus we add the devices * * Add devices in the bus' internal device list to the system. */ void mcb_bus_add_devices(const struct mcb_bus *bus) { bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_bus_add_devices); bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_bus_add_child); } EXPORT_SYMBOL_GPL(mcb_bus_add_devices); /** * mcb_request_mem() - Request memory * @dev: The @mcb_device the memory is for * @name: The name for the memory reference. * * Request memory for a @mcb_device. If @name is NULL the driver name will * be used. */ struct resource *mcb_request_mem(struct mcb_device *dev, const char *name) { struct resource *mem; u32 size; if (!name) name = dev->dev.driver->name; size = resource_size(&dev->mem); mem = request_mem_region(dev->mem.start, size, name); if (!mem) return ERR_PTR(-EBUSY); return mem; } EXPORT_SYMBOL_GPL(mcb_request_mem); /** * mcb_release_mem() - Release memory requested by device * @dev: The @mcb_device that requested the memory * * Release memory that was prior requested via @mcb_request_mem(). */ void mcb_release_mem(struct resource *mem) { u32 size; size = resource_size(mem); release_mem_region(mem->start, size); } EXPORT_SYMBOL_GPL(mcb_release_mem); static int __mcb_get_irq(struct mcb_device *dev) { struct resource *irq = &dev->irq; return irq->start; } /** * mcb_get_irq() - Get device's IRQ number * @dev: The @mcb_device the IRQ is for * * Get the IRQ number of a given @mcb_device. */ int mcb_get_irq(struct mcb_device *dev) { struct mcb_bus *bus = dev->bus; if (bus->get_irq) return bus->get_irq(dev); return __mcb_get_irq(dev); } EXPORT_SYMBOL_GPL(mcb_get_irq); static int mcb_init(void) { return bus_register(&mcb_bus_type); } static void mcb_exit(void) { bus_unregister(&mcb_bus_type); } /* mcb must be initialized after PCI but before the chameleon drivers. * That means we must use some initcall between subsys_initcall and * device_initcall. */ fs_initcall(mcb_init); module_exit(mcb_exit); MODULE_DESCRIPTION("MEN Chameleon Bus Driver"); MODULE_AUTHOR("Johannes Thumshirn <johannes.thumshirn@men.de>"); MODULE_LICENSE("GPL v2");