// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2016-2017 Linaro Ltd., Rob Herring * * Based on drivers/spmi/spmi.c: * Copyright (c) 2012-2015, The Linux Foundation. All rights reserved. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include static bool is_registered; static DEFINE_IDA(ctrl_ida); static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf) { int len; len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1); if (len != -ENODEV) return len; return of_device_modalias(dev, buf, PAGE_SIZE); } static DEVICE_ATTR_RO(modalias); static struct attribute *serdev_device_attrs[] = { &dev_attr_modalias.attr, NULL, }; ATTRIBUTE_GROUPS(serdev_device); static int serdev_device_uevent(const struct device *dev, struct kobj_uevent_env *env) { int rc; /* TODO: platform modalias */ rc = acpi_device_uevent_modalias(dev, env); if (rc != -ENODEV) return rc; return of_device_uevent_modalias(dev, env); } static void serdev_device_release(struct device *dev) { struct serdev_device *serdev = to_serdev_device(dev); kfree(serdev); } static const struct device_type serdev_device_type = { .groups = serdev_device_groups, .uevent = serdev_device_uevent, .release = serdev_device_release, }; static bool is_serdev_device(const struct device *dev) { return dev->type == &serdev_device_type; } static void serdev_ctrl_release(struct device *dev) { struct serdev_controller *ctrl = to_serdev_controller(dev); ida_free(&ctrl_ida, ctrl->nr); kfree(ctrl); } static const struct device_type serdev_ctrl_type = { .release = serdev_ctrl_release, }; static int serdev_device_match(struct device *dev, const struct device_driver *drv) { if (!is_serdev_device(dev)) return 0; /* TODO: platform matching */ if (acpi_driver_match_device(dev, drv)) return 1; return of_driver_match_device(dev, drv); } /** * serdev_device_add() - add a device previously constructed via serdev_device_alloc() * @serdev: serdev_device to be added */ int serdev_device_add(struct serdev_device *serdev) { struct serdev_controller *ctrl = serdev->ctrl; struct device *parent = serdev->dev.parent; int err; dev_set_name(&serdev->dev, "%s-%d", dev_name(parent), serdev->nr); /* Only a single slave device is currently supported. */ if (ctrl->serdev) { dev_err(&serdev->dev, "controller busy\n"); return -EBUSY; } ctrl->serdev = serdev; err = device_add(&serdev->dev); if (err < 0) { dev_err(&serdev->dev, "Can't add %s, status %pe\n", dev_name(&serdev->dev), ERR_PTR(err)); goto err_clear_serdev; } dev_dbg(&serdev->dev, "device %s registered\n", dev_name(&serdev->dev)); return 0; err_clear_serdev: ctrl->serdev = NULL; return err; } EXPORT_SYMBOL_GPL(serdev_device_add); /** * serdev_device_remove(): remove an serdev device * @serdev: serdev_device to be removed */ void serdev_device_remove(struct serdev_device *serdev) { struct serdev_controller *ctrl = serdev->ctrl; device_unregister(&serdev->dev); ctrl->serdev = NULL; } EXPORT_SYMBOL_GPL(serdev_device_remove); int serdev_device_open(struct serdev_device *serdev) { struct serdev_controller *ctrl = serdev->ctrl; int ret; if (!ctrl || !ctrl->ops->open) return -EINVAL; ret = ctrl->ops->open(ctrl); if (ret) return ret; ret = pm_runtime_get_sync(&ctrl->dev); if (ret < 0) { pm_runtime_put_noidle(&ctrl->dev); goto err_close; } return 0; err_close: if (ctrl->ops->close) ctrl->ops->close(ctrl); return ret; } EXPORT_SYMBOL_GPL(serdev_device_open); void serdev_device_close(struct serdev_device *serdev) { struct serdev_controller *ctrl = serdev->ctrl; if (!ctrl || !ctrl->ops->close) return; pm_runtime_put(&ctrl->dev); ctrl->ops->close(ctrl); } EXPORT_SYMBOL_GPL(serdev_device_close); static void devm_serdev_device_close(void *serdev) { serdev_device_close(serdev); } int devm_serdev_device_open(struct device *dev, struct serdev_device *serdev) { int ret; ret = serdev_device_open(serdev); if (ret) return ret; return devm_add_action_or_reset(dev, devm_serdev_device_close, serdev); } EXPORT_SYMBOL_GPL(devm_serdev_device_open); void serdev_device_write_wakeup(struct serdev_device *serdev) { complete(&serdev->write_comp); } EXPORT_SYMBOL_GPL(serdev_device_write_wakeup); /** * serdev_device_write_buf() - write data asynchronously * @serdev: serdev device * @buf: data to be written * @count: number of bytes to write * * Write data to the device asynchronously. * * Note that any accepted data has only been buffered by the controller; use * serdev_device_wait_until_sent() to make sure the controller write buffer * has actually been emptied. * * Return: The number of bytes written (less than count if not enough room in * the write buffer), or a negative errno on errors. */ int serdev_device_write_buf(struct serdev_device *serdev, const u8 *buf, size_t count) { struct serdev_controller *ctrl = serdev->ctrl; if (!ctrl || !ctrl->ops->write_buf) return -EINVAL; return ctrl->ops->write_buf(ctrl, buf, count); } EXPORT_SYMBOL_GPL(serdev_device_write_buf); /** * serdev_device_write() - write data synchronously * @serdev: serdev device * @buf: data to be written * @count: number of bytes to write * @timeout: timeout in jiffies, or 0 to wait indefinitely * * Write data to the device synchronously by repeatedly calling * serdev_device_write() until the controller has accepted all data (unless * interrupted by a timeout or a signal). * * Note that any accepted data has only been buffered by the controller; use * serdev_device_wait_until_sent() to make sure the controller write buffer * has actually been emptied. * * Note that this function depends on serdev_device_write_wakeup() being * called in the serdev driver write_wakeup() callback. * * Return: The number of bytes written (less than count if interrupted), * -ETIMEDOUT or -ERESTARTSYS if interrupted before any bytes were written, or * a negative errno on errors. */ ssize_t serdev_device_write(struct serdev_device *serdev, const u8 *buf, size_t count, long timeout) { struct serdev_controller *ctrl = serdev->ctrl; size_t written = 0; ssize_t ret; if (!ctrl || !ctrl->ops->write_buf || !serdev->ops->write_wakeup) return -EINVAL; if (timeout == 0) timeout = MAX_SCHEDULE_TIMEOUT; mutex_lock(&serdev->write_lock); do { reinit_completion(&serdev->write_comp); ret = ctrl->ops->write_buf(ctrl, buf, count); if (ret < 0) break; written += ret; buf += ret; count -= ret; if (count == 0) break; timeout = wait_for_completion_interruptible_timeout(&serdev->write_comp, timeout); } while (timeout > 0); mutex_unlock(&serdev->write_lock); if (ret < 0) return ret; if (timeout <= 0 && written == 0) { if (timeout == -ERESTARTSYS) return -ERESTARTSYS; else return -ETIMEDOUT; } return written; } EXPORT_SYMBOL_GPL(serdev_device_write); void serdev_device_write_flush(struct serdev_device *serdev) { struct serdev_controller *ctrl = serdev->ctrl; if (!ctrl || !ctrl->ops->write_flush) return; ctrl->ops->write_flush(ctrl); } EXPORT_SYMBOL_GPL(serdev_device_write_flush); int serdev_device_write_room(struct serdev_device *serdev) { struct serdev_controller *ctrl = serdev->ctrl; if (!ctrl || !ctrl->ops->write_room) return 0; return serdev->ctrl->ops->write_room(ctrl); } EXPORT_SYMBOL_GPL(serdev_device_write_room); unsigned int serdev_device_set_baudrate(struct serdev_device *serdev, unsigned int speed) { struct serdev_controller *ctrl = serdev->ctrl; if (!ctrl || !ctrl->ops->set_baudrate) return 0; return ctrl->ops->set_baudrate(ctrl, speed); } EXPORT_SYMBOL_GPL(serdev_device_set_baudrate); void serdev_device_set_flow_control(struct serdev_device *serdev, bool enable) { struct serdev_controller *ctrl = serdev->ctrl; if (!ctrl || !ctrl->ops->set_flow_control) return; ctrl->ops->set_flow_control(ctrl, enable); } EXPORT_SYMBOL_GPL(serdev_device_set_flow_control); int serdev_device_set_parity(struct serdev_device *serdev, enum serdev_parity parity) { struct serdev_controller *ctrl = serdev->ctrl; if (!ctrl || !ctrl->ops->set_parity) return -EOPNOTSUPP; return ctrl->ops->set_parity(ctrl, parity); } EXPORT_SYMBOL_GPL(serdev_device_set_parity); void serdev_device_wait_until_sent(struct serdev_device *serdev, long timeout) { struct serdev_controller *ctrl = serdev->ctrl; if (!ctrl || !ctrl->ops->wait_until_sent) return; ctrl->ops->wait_until_sent(ctrl, timeout); } EXPORT_SYMBOL_GPL(serdev_device_wait_until_sent); int serdev_device_get_tiocm(struct serdev_device *serdev) { struct serdev_controller *ctrl = serdev->ctrl; if (!ctrl || !ctrl->ops->get_tiocm) return -EOPNOTSUPP; return ctrl->ops->get_tiocm(ctrl); } EXPORT_SYMBOL_GPL(serdev_device_get_tiocm); int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear) { struct serdev_controller *ctrl = serdev->ctrl; if (!ctrl || !ctrl->ops->set_tiocm) return -EOPNOTSUPP; return ctrl->ops->set_tiocm(ctrl, set, clear); } EXPORT_SYMBOL_GPL(serdev_device_set_tiocm); int serdev_device_break_ctl(struct serdev_device *serdev, int break_state) { struct serdev_controller *ctrl = serdev->ctrl; if (!ctrl || !ctrl->ops->break_ctl) return -EOPNOTSUPP; return ctrl->ops->break_ctl(ctrl, break_state); } EXPORT_SYMBOL_GPL(serdev_device_break_ctl); static int serdev_drv_probe(struct device *dev) { const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver); int ret; ret = dev_pm_domain_attach(dev, true); if (ret) return ret; ret = sdrv->probe(to_serdev_device(dev)); if (ret) dev_pm_domain_detach(dev, true); return ret; } static void serdev_drv_remove(struct device *dev) { const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver); if (sdrv->remove) sdrv->remove(to_serdev_device(dev)); dev_pm_domain_detach(dev, true); } static const struct bus_type serdev_bus_type = { .name = "serial", .match = serdev_device_match, .probe = serdev_drv_probe, .remove = serdev_drv_remove, }; /** * serdev_device_alloc() - Allocate a new serdev device * @ctrl: associated controller * * Caller is responsible for either calling serdev_device_add() to add the * newly allocated controller, or calling serdev_device_put() to discard it. */ struct serdev_device *serdev_device_alloc(struct serdev_controller *ctrl) { struct serdev_device *serdev; serdev = kzalloc(sizeof(*serdev), GFP_KERNEL); if (!serdev) return NULL; serdev->ctrl = ctrl; device_initialize(&serdev->dev); serdev->dev.parent = &ctrl->dev; serdev->dev.bus = &serdev_bus_type; serdev->dev.type = &serdev_device_type; init_completion(&serdev->write_comp); mutex_init(&serdev->write_lock); return serdev; } EXPORT_SYMBOL_GPL(serdev_device_alloc); /** * serdev_controller_alloc() - Allocate a new serdev controller * @host: serial port hardware controller device * @parent: parent device * @size: size of private data * * Caller is responsible for either calling serdev_controller_add() to add the * newly allocated controller, or calling serdev_controller_put() to discard it. * The allocated private data region may be accessed via * serdev_controller_get_drvdata() */ struct serdev_controller *serdev_controller_alloc(struct device *host, struct device *parent, size_t size) { struct serdev_controller *ctrl; int id; if (WARN_ON(!parent)) return NULL; ctrl = kzalloc(sizeof(*ctrl) + size, GFP_KERNEL); if (!ctrl) return NULL; id = ida_alloc(&ctrl_ida, GFP_KERNEL); if (id < 0) { dev_err(parent, "unable to allocate serdev controller identifier.\n"); goto err_free; } ctrl->nr = id; device_initialize(&ctrl->dev); ctrl->dev.type = &serdev_ctrl_type; ctrl->dev.bus = &serdev_bus_type; ctrl->dev.parent = parent; ctrl->host = host; device_set_node(&ctrl->dev, dev_fwnode(host)); serdev_controller_set_drvdata(ctrl, &ctrl[1]); dev_set_name(&ctrl->dev, "serial%d", id); pm_runtime_no_callbacks(&ctrl->dev); pm_suspend_ignore_children(&ctrl->dev, true); dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id); return ctrl; err_free: kfree(ctrl); return NULL; } EXPORT_SYMBOL_GPL(serdev_controller_alloc); static int of_serdev_register_devices(struct serdev_controller *ctrl) { struct device_node *node; struct serdev_device *serdev = NULL; int err; bool found = false; for_each_available_child_of_node(ctrl->dev.of_node, node) { if (!of_property_present(node, "compatible")) continue; dev_dbg(&ctrl->dev, "adding child %pOF\n", node); serdev = serdev_device_alloc(ctrl); if (!serdev) continue; device_set_node(&serdev->dev, of_fwnode_handle(node)); err = serdev_device_add(serdev); if (err) { dev_err(&serdev->dev, "failure adding device. status %pe\n", ERR_PTR(err)); serdev_device_put(serdev); } else found = true; } if (!found) return -ENODEV; return 0; } #ifdef CONFIG_ACPI #define SERDEV_ACPI_MAX_SCAN_DEPTH 32 struct acpi_serdev_lookup { acpi_handle device_handle; acpi_handle controller_handle; int n; int index; }; /** * serdev_acpi_get_uart_resource - Gets UARTSerialBus resource if type matches * @ares: ACPI resource * @uart: Pointer to UARTSerialBus resource will be returned here * * Checks if the given ACPI resource is of type UARTSerialBus. * In this case, returns a pointer to it to the caller. * * Return: True if resource type is of UARTSerialBus, otherwise false. */ bool serdev_acpi_get_uart_resource(struct acpi_resource *ares, struct acpi_resource_uart_serialbus **uart) { struct acpi_resource_uart_serialbus *sb; if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) return false; sb = &ares->data.uart_serial_bus; if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_UART) return false; *uart = sb; return true; } EXPORT_SYMBOL_GPL(serdev_acpi_get_uart_resource); static int acpi_serdev_parse_resource(struct acpi_resource *ares, void *data) { struct acpi_serdev_lookup *lookup = data; struct acpi_resource_uart_serialbus *sb; acpi_status status; if (!serdev_acpi_get_uart_resource(ares, &sb)) return 1; if (lookup->index != -1 && lookup->n++ != lookup->index) return 1; status = acpi_get_handle(lookup->device_handle, sb->resource_source.string_ptr, &lookup->controller_handle); if (ACPI_FAILURE(status)) return 1; /* * NOTE: Ideally, we would also want to retrieve other properties here, * once setting them before opening the device is supported by serdev. */ return 1; } static int acpi_serdev_do_lookup(struct acpi_device *adev, struct acpi_serdev_lookup *lookup) { struct list_head resource_list; int ret; lookup->device_handle = acpi_device_handle(adev); lookup->controller_handle = NULL; lookup->n = 0; INIT_LIST_HEAD(&resource_list); ret = acpi_dev_get_resources(adev, &resource_list, acpi_serdev_parse_resource, lookup); acpi_dev_free_resource_list(&resource_list); if (ret < 0) return -EINVAL; return 0; } static int acpi_serdev_check_resources(struct serdev_controller *ctrl, struct acpi_device *adev) { struct acpi_serdev_lookup lookup; int ret; if (acpi_bus_get_status(adev) || !adev->status.present) return -EINVAL; /* Look for UARTSerialBusV2 resource */ lookup.index = -1; // we only care for the last device ret = acpi_serdev_do_lookup(adev, &lookup); if (ret) return ret; /* * Apple machines provide an empty resource template, so on those * machines just look for immediate children with a "baud" property * (from the _DSM method) instead. */ if (!lookup.controller_handle && x86_apple_machine && !acpi_dev_get_property(adev, "baud", ACPI_TYPE_BUFFER, NULL)) acpi_get_parent(adev->handle, &lookup.controller_handle); /* Make sure controller and ResourceSource handle match */ if (!device_match_acpi_handle(ctrl->host, lookup.controller_handle)) return -ENODEV; return 0; } static acpi_status acpi_serdev_register_device(struct serdev_controller *ctrl, struct acpi_device *adev) { struct serdev_device *serdev; int err; serdev = serdev_device_alloc(ctrl); if (!serdev) { dev_err(&ctrl->dev, "failed to allocate serdev device for %s\n", dev_name(&adev->dev)); return AE_NO_MEMORY; } ACPI_COMPANION_SET(&serdev->dev, adev); acpi_device_set_enumerated(adev); err = serdev_device_add(serdev); if (err) { dev_err(&serdev->dev, "failure adding ACPI serdev device. status %pe\n", ERR_PTR(err)); serdev_device_put(serdev); } return AE_OK; } static const struct acpi_device_id serdev_acpi_devices_blacklist[] = { { "INT3511", 0 }, { "INT3512", 0 }, { }, }; static acpi_status acpi_serdev_add_device(acpi_handle handle, u32 level, void *data, void **return_value) { struct acpi_device *adev = acpi_fetch_acpi_dev(handle); struct serdev_controller *ctrl = data; if (!adev || acpi_device_enumerated(adev)) return AE_OK; /* Skip if black listed */ if (!acpi_match_device_ids(adev, serdev_acpi_devices_blacklist)) return AE_OK; if (acpi_serdev_check_resources(ctrl, adev)) return AE_OK; return acpi_serdev_register_device(ctrl, adev); } static int acpi_serdev_register_devices(struct serdev_controller *ctrl) { acpi_status status; bool skip; int ret; if (!has_acpi_companion(ctrl->host)) return -ENODEV; /* * Skip registration on boards where the ACPI tables are known to * contain buggy devices. Note serdev_controller_add() must still * succeed in this case, so that the proper serdev devices can be * added "manually" later. */ ret = acpi_quirk_skip_serdev_enumeration(ctrl->host, &skip); if (ret) return ret; if (skip) return 0; status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, SERDEV_ACPI_MAX_SCAN_DEPTH, acpi_serdev_add_device, NULL, ctrl, NULL); if (ACPI_FAILURE(status)) dev_warn(&ctrl->dev, "failed to enumerate serdev slaves\n"); if (!ctrl->serdev) return -ENODEV; return 0; } #else static inline int acpi_serdev_register_devices(struct serdev_controller *ctrl) { return -ENODEV; } #endif /* CONFIG_ACPI */ /** * serdev_controller_add() - Add an serdev controller * @ctrl: controller to be registered. * * Register a controller previously allocated via serdev_controller_alloc() with * the serdev core. */ int serdev_controller_add(struct serdev_controller *ctrl) { int ret_of, ret_acpi, ret; /* Can't register until after driver model init */ if (WARN_ON(!is_registered)) return -EAGAIN; ret = device_add(&ctrl->dev); if (ret) return ret; pm_runtime_enable(&ctrl->dev); ret_of = of_serdev_register_devices(ctrl); ret_acpi = acpi_serdev_register_devices(ctrl); if (ret_of && ret_acpi) { dev_dbg(&ctrl->dev, "no devices registered: of:%pe acpi:%pe\n", ERR_PTR(ret_of), ERR_PTR(ret_acpi)); ret = -ENODEV; goto err_rpm_disable; } dev_dbg(&ctrl->dev, "serdev%d registered: dev:%p\n", ctrl->nr, &ctrl->dev); return 0; err_rpm_disable: pm_runtime_disable(&ctrl->dev); device_del(&ctrl->dev); return ret; }; EXPORT_SYMBOL_GPL(serdev_controller_add); /* Remove a device associated with a controller */ static int serdev_remove_device(struct device *dev, void *data) { struct serdev_device *serdev = to_serdev_device(dev); if (dev->type == &serdev_device_type) serdev_device_remove(serdev); return 0; } /** * serdev_controller_remove(): remove an serdev controller * @ctrl: controller to remove * * Remove a serdev controller. Caller is responsible for calling * serdev_controller_put() to discard the allocated controller. */ void serdev_controller_remove(struct serdev_controller *ctrl) { if (!ctrl) return; device_for_each_child(&ctrl->dev, NULL, serdev_remove_device); pm_runtime_disable(&ctrl->dev); device_del(&ctrl->dev); } EXPORT_SYMBOL_GPL(serdev_controller_remove); /** * __serdev_device_driver_register() - Register client driver with serdev core * @sdrv: client driver to be associated with client-device. * @owner: client driver owner to set. * * This API will register the client driver with the serdev framework. * It is typically called from the driver's module-init function. */ int __serdev_device_driver_register(struct serdev_device_driver *sdrv, struct module *owner) { sdrv->driver.bus = &serdev_bus_type; sdrv->driver.owner = owner; /* force drivers to async probe so I/O is possible in probe */ sdrv->driver.probe_type = PROBE_PREFER_ASYNCHRONOUS; return driver_register(&sdrv->driver); } EXPORT_SYMBOL_GPL(__serdev_device_driver_register); static void __exit serdev_exit(void) { bus_unregister(&serdev_bus_type); ida_destroy(&ctrl_ida); } module_exit(serdev_exit); static int __init serdev_init(void) { int ret; ret = bus_register(&serdev_bus_type); if (ret) return ret; is_registered = true; return 0; } /* Must be before serial drivers register */ postcore_initcall(serdev_init); MODULE_AUTHOR("Rob Herring "); MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("Serial attached device bus");