diff options
Diffstat (limited to 'drivers/peci/core.c')
-rw-r--r-- | drivers/peci/core.c | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/drivers/peci/core.c b/drivers/peci/core.c new file mode 100644 index 0000000000..0f83a9c609 --- /dev/null +++ b/drivers/peci/core.c @@ -0,0 +1,236 @@ +// SPDX-License-Identifier: GPL-2.0-only +// Copyright (c) 2018-2021 Intel Corporation + +#include <linux/bug.h> +#include <linux/device.h> +#include <linux/export.h> +#include <linux/idr.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/peci.h> +#include <linux/pm_runtime.h> +#include <linux/property.h> +#include <linux/slab.h> + +#include "internal.h" + +static DEFINE_IDA(peci_controller_ida); + +static void peci_controller_dev_release(struct device *dev) +{ + struct peci_controller *controller = to_peci_controller(dev); + + mutex_destroy(&controller->bus_lock); + ida_free(&peci_controller_ida, controller->id); + kfree(controller); +} + +struct device_type peci_controller_type = { + .release = peci_controller_dev_release, +}; + +int peci_controller_scan_devices(struct peci_controller *controller) +{ + int ret; + u8 addr; + + for (addr = PECI_BASE_ADDR; addr < PECI_BASE_ADDR + PECI_DEVICE_NUM_MAX; addr++) { + ret = peci_device_create(controller, addr); + if (ret) + return ret; + } + + return 0; +} + +static struct peci_controller *peci_controller_alloc(struct device *dev, + const struct peci_controller_ops *ops) +{ + struct peci_controller *controller; + int ret; + + if (!ops->xfer) + return ERR_PTR(-EINVAL); + + controller = kzalloc(sizeof(*controller), GFP_KERNEL); + if (!controller) + return ERR_PTR(-ENOMEM); + + ret = ida_alloc_max(&peci_controller_ida, U8_MAX, GFP_KERNEL); + if (ret < 0) + goto err; + controller->id = ret; + + controller->ops = ops; + + controller->dev.parent = dev; + controller->dev.bus = &peci_bus_type; + controller->dev.type = &peci_controller_type; + + device_initialize(&controller->dev); + + mutex_init(&controller->bus_lock); + + return controller; + +err: + kfree(controller); + return ERR_PTR(ret); +} + +static int unregister_child(struct device *dev, void *dummy) +{ + peci_device_destroy(to_peci_device(dev)); + + return 0; +} + +static void unregister_controller(void *_controller) +{ + struct peci_controller *controller = _controller; + + /* + * Detach any active PECI devices. This can't fail, thus we do not + * check the returned value. + */ + device_for_each_child_reverse(&controller->dev, NULL, unregister_child); + + device_unregister(&controller->dev); + + fwnode_handle_put(controller->dev.fwnode); + + pm_runtime_disable(&controller->dev); +} + +/** + * devm_peci_controller_add() - add PECI controller + * @dev: device for devm operations + * @ops: pointer to controller specific methods + * + * In final stage of its probe(), peci_controller driver calls + * devm_peci_controller_add() to register itself with the PECI bus. + * + * Return: Pointer to the newly allocated controller or ERR_PTR() in case of failure. + */ +struct peci_controller *devm_peci_controller_add(struct device *dev, + const struct peci_controller_ops *ops) +{ + struct peci_controller *controller; + int ret; + + controller = peci_controller_alloc(dev, ops); + if (IS_ERR(controller)) + return controller; + + ret = dev_set_name(&controller->dev, "peci-%d", controller->id); + if (ret) + goto err_put; + + pm_runtime_no_callbacks(&controller->dev); + pm_suspend_ignore_children(&controller->dev, true); + pm_runtime_enable(&controller->dev); + + device_set_node(&controller->dev, fwnode_handle_get(dev_fwnode(dev))); + + ret = device_add(&controller->dev); + if (ret) + goto err_fwnode; + + ret = devm_add_action_or_reset(dev, unregister_controller, controller); + if (ret) + return ERR_PTR(ret); + + /* + * Ignoring retval since failures during scan are non-critical for + * controller itself. + */ + peci_controller_scan_devices(controller); + + return controller; + +err_fwnode: + fwnode_handle_put(controller->dev.fwnode); + + pm_runtime_disable(&controller->dev); + +err_put: + put_device(&controller->dev); + + return ERR_PTR(ret); +} +EXPORT_SYMBOL_NS_GPL(devm_peci_controller_add, PECI); + +static const struct peci_device_id * +peci_bus_match_device_id(const struct peci_device_id *id, struct peci_device *device) +{ + while (id->family != 0) { + if (id->family == device->info.family && + id->model == device->info.model) + return id; + id++; + } + + return NULL; +} + +static int peci_bus_device_match(struct device *dev, struct device_driver *drv) +{ + struct peci_device *device = to_peci_device(dev); + struct peci_driver *peci_drv = to_peci_driver(drv); + + if (dev->type != &peci_device_type) + return 0; + + return !!peci_bus_match_device_id(peci_drv->id_table, device); +} + +static int peci_bus_device_probe(struct device *dev) +{ + struct peci_device *device = to_peci_device(dev); + struct peci_driver *driver = to_peci_driver(dev->driver); + + return driver->probe(device, peci_bus_match_device_id(driver->id_table, device)); +} + +static void peci_bus_device_remove(struct device *dev) +{ + struct peci_device *device = to_peci_device(dev); + struct peci_driver *driver = to_peci_driver(dev->driver); + + if (driver->remove) + driver->remove(device); +} + +struct bus_type peci_bus_type = { + .name = "peci", + .match = peci_bus_device_match, + .probe = peci_bus_device_probe, + .remove = peci_bus_device_remove, + .bus_groups = peci_bus_groups, +}; + +static int __init peci_init(void) +{ + int ret; + + ret = bus_register(&peci_bus_type); + if (ret < 0) { + pr_err("peci: failed to register PECI bus type!\n"); + return ret; + } + + return 0; +} +module_init(peci_init); + +static void __exit peci_exit(void) +{ + bus_unregister(&peci_bus_type); +} +module_exit(peci_exit); + +MODULE_AUTHOR("Jason M Bills <jason.m.bills@linux.intel.com>"); +MODULE_AUTHOR("Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>"); +MODULE_AUTHOR("Iwona Winiarska <iwona.winiarska@intel.com>"); +MODULE_DESCRIPTION("PECI bus core module"); +MODULE_LICENSE("GPL"); |