| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * MEN Chameleon Bus. |
| * |
| * Copyright (C) 2013 MEN Mikroelektronik GmbH (www.men.de) |
| * Author: Johannes Thumshirn <johannes.thumshirn@men.de> |
| */ |
| #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(const struct device *dev, struct kobj_uevent_env *env) |
| { |
| const 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; |
| struct module *carrier_mod; |
| int ret; |
| |
| found_id = mcb_match_id(mdrv->id_table, mdev); |
| if (!found_id) |
| return -ENODEV; |
| |
| carrier_mod = mdev->dev.parent->driver->owner; |
| if (!try_module_get(carrier_mod)) |
| return -EINVAL; |
| |
| get_device(dev); |
| ret = mdrv->probe(mdev, found_id); |
| if (ret) { |
| module_put(carrier_mod); |
| put_device(dev); |
| } |
| |
| return ret; |
| } |
| |
| static void mcb_remove(struct device *dev) |
| { |
| struct mcb_driver *mdrv = to_mcb_driver(dev->driver); |
| struct mcb_device *mdev = to_mcb_device(dev); |
| struct module *carrier_mod; |
| |
| mdrv->remove(mdev); |
| |
| carrier_mod = mdev->dev.parent->driver->owner; |
| module_put(carrier_mod); |
| |
| put_device(&mdev->dev); |
| } |
| |
| static void mcb_shutdown(struct device *dev) |
| { |
| struct mcb_driver *mdrv = to_mcb_driver(dev->driver); |
| struct mcb_device *mdev = to_mcb_device(dev); |
| |
| if (mdrv && mdrv->shutdown) |
| mdrv->shutdown(mdev); |
| } |
| |
| static ssize_t revision_show(struct device *dev, struct device_attribute *attr, |
| char *buf) |
| { |
| struct mcb_bus *bus = to_mcb_bus(dev); |
| |
| return scnprintf(buf, PAGE_SIZE, "%d\n", bus->revision); |
| } |
| static DEVICE_ATTR_RO(revision); |
| |
| static ssize_t model_show(struct device *dev, struct device_attribute *attr, |
| char *buf) |
| { |
| struct mcb_bus *bus = to_mcb_bus(dev); |
| |
| return scnprintf(buf, PAGE_SIZE, "%c\n", bus->model); |
| } |
| static DEVICE_ATTR_RO(model); |
| |
| static ssize_t minor_show(struct device *dev, struct device_attribute *attr, |
| char *buf) |
| { |
| struct mcb_bus *bus = to_mcb_bus(dev); |
| |
| return scnprintf(buf, PAGE_SIZE, "%d\n", bus->minor); |
| } |
| static DEVICE_ATTR_RO(minor); |
| |
| static ssize_t name_show(struct device *dev, struct device_attribute *attr, |
| char *buf) |
| { |
| struct mcb_bus *bus = to_mcb_bus(dev); |
| |
| return scnprintf(buf, PAGE_SIZE, "%s\n", bus->name); |
| } |
| static DEVICE_ATTR_RO(name); |
| |
| static struct attribute *mcb_bus_attrs[] = { |
| &dev_attr_revision.attr, |
| &dev_attr_model.attr, |
| &dev_attr_minor.attr, |
| &dev_attr_name.attr, |
| NULL, |
| }; |
| |
| static const struct attribute_group mcb_carrier_group = { |
| .attrs = mcb_bus_attrs, |
| }; |
| |
| static const struct attribute_group *mcb_carrier_groups[] = { |
| &mcb_carrier_group, |
| NULL, |
| }; |
| |
| |
| static struct bus_type mcb_bus_type = { |
| .name = "mcb", |
| .match = mcb_match, |
| .uevent = mcb_uevent, |
| .probe = mcb_probe, |
| .remove = mcb_remove, |
| .shutdown = mcb_shutdown, |
| }; |
| |
| static struct device_type mcb_carrier_device_type = { |
| .name = "mcb-carrier", |
| .groups = mcb_carrier_groups, |
| }; |
| |
| /** |
| * __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_NS_GPL(__mcb_register_driver, MCB); |
| |
| /** |
| * 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_NS_GPL(mcb_unregister_driver, MCB); |
| |
| 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); |
| mcb_bus_get(bus); |
| dev->dev.bus = &mcb_bus_type; |
| dev->dev.parent = bus->dev.parent; |
| dev->dev.release = mcb_release_dev; |
| dev->dma_dev = bus->carrier; |
| |
| 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_NS_GPL(mcb_device_register, MCB); |
| |
| static void mcb_free_bus(struct device *dev) |
| { |
| struct mcb_bus *bus = to_mcb_bus(dev); |
| |
| put_device(bus->carrier); |
| ida_free(&mcb_ida, bus->bus_nr); |
| kfree(bus); |
| } |
| |
| /** |
| * 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; |
| int rc; |
| |
| bus = kzalloc(sizeof(struct mcb_bus), GFP_KERNEL); |
| if (!bus) |
| return ERR_PTR(-ENOMEM); |
| |
| bus_nr = ida_alloc(&mcb_ida, GFP_KERNEL); |
| if (bus_nr < 0) { |
| kfree(bus); |
| return ERR_PTR(bus_nr); |
| } |
| |
| bus->bus_nr = bus_nr; |
| bus->carrier = get_device(carrier); |
| |
| device_initialize(&bus->dev); |
| bus->dev.parent = carrier; |
| bus->dev.bus = &mcb_bus_type; |
| bus->dev.type = &mcb_carrier_device_type; |
| bus->dev.release = &mcb_free_bus; |
| |
| dev_set_name(&bus->dev, "mcb:%d", bus_nr); |
| rc = device_add(&bus->dev); |
| if (rc) |
| goto err_put; |
| |
| return bus; |
| |
| err_put: |
| put_device(&bus->dev); |
| return ERR_PTR(rc); |
| } |
| EXPORT_SYMBOL_NS_GPL(mcb_alloc_bus, MCB); |
| |
| 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); |
| } |
| EXPORT_SYMBOL_NS_GPL(mcb_release_bus, MCB); |
| |
| /** |
| * 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_NS_GPL(mcb_bus_get, MCB); |
| |
| /** |
| * 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_NS_GPL(mcb_bus_put, MCB); |
| |
| /** |
| * 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; |
| |
| dev->bus = bus; |
| |
| return dev; |
| } |
| EXPORT_SYMBOL_NS_GPL(mcb_alloc_dev, MCB); |
| |
| /** |
| * 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_NS_GPL(mcb_free_dev, MCB); |
| |
| static int __mcb_bus_add_devices(struct device *dev, void *data) |
| { |
| int retval; |
| |
| retval = device_attach(dev); |
| if (retval < 0) { |
| dev_err(dev, "Error adding device (%d)\n", retval); |
| return retval; |
| } |
| |
| 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); |
| } |
| EXPORT_SYMBOL_NS_GPL(mcb_bus_add_devices, MCB); |
| |
| /** |
| * mcb_get_resource() - get a resource for a mcb device |
| * @dev: the mcb device |
| * @type: the type of resource |
| */ |
| struct resource *mcb_get_resource(struct mcb_device *dev, unsigned int type) |
| { |
| if (type == IORESOURCE_MEM) |
| return &dev->mem; |
| else if (type == IORESOURCE_IRQ) |
| return &dev->irq; |
| else |
| return NULL; |
| } |
| EXPORT_SYMBOL_NS_GPL(mcb_get_resource, MCB); |
| |
| /** |
| * 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_NS_GPL(mcb_request_mem, MCB); |
| |
| /** |
| * 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_NS_GPL(mcb_release_mem, MCB); |
| |
| static int __mcb_get_irq(struct mcb_device *dev) |
| { |
| struct resource *irq; |
| |
| irq = mcb_get_resource(dev, IORESOURCE_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_NS_GPL(mcb_get_irq, MCB); |
| |
| static int mcb_init(void) |
| { |
| return bus_register(&mcb_bus_type); |
| } |
| |
| static void mcb_exit(void) |
| { |
| ida_destroy(&mcb_ida); |
| 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"); |