diff options
Diffstat (limited to 'drivers/tty/serdev')
| -rw-r--r-- | drivers/tty/serdev/Kconfig | 25 | ||||
| -rw-r--r-- | drivers/tty/serdev/Makefile | 6 | ||||
| -rw-r--r-- | drivers/tty/serdev/core.c | 874 | ||||
| -rw-r--r-- | drivers/tty/serdev/serdev-ttyport.c | 318 |
4 files changed, 1223 insertions, 0 deletions
diff --git a/drivers/tty/serdev/Kconfig b/drivers/tty/serdev/Kconfig new file mode 100644 index 000000000..46ae732bf --- /dev/null +++ b/drivers/tty/serdev/Kconfig @@ -0,0 +1,25 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Serial bus device driver configuration +# +menuconfig SERIAL_DEV_BUS + tristate "Serial device bus" + help + Core support for devices connected via a serial port. + + Note that you typically also want to enable TTY port controller support. + +if SERIAL_DEV_BUS + +config SERIAL_DEV_CTRL_TTYPORT + bool "Serial device TTY port controller" + help + Say Y here if you want to use the Serial device bus with common TTY + drivers (e.g. serial drivers). + + If unsure, say Y. + depends on TTY + depends on SERIAL_DEV_BUS != m + default y + +endif diff --git a/drivers/tty/serdev/Makefile b/drivers/tty/serdev/Makefile new file mode 100644 index 000000000..078417e5b --- /dev/null +++ b/drivers/tty/serdev/Makefile @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0 +serdev-objs := core.o + +obj-$(CONFIG_SERIAL_DEV_BUS) += serdev.o + +obj-$(CONFIG_SERIAL_DEV_CTRL_TTYPORT) += serdev-ttyport.o diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c new file mode 100644 index 000000000..0180e1e4e --- /dev/null +++ b/drivers/tty/serdev/core.c @@ -0,0 +1,874 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <robh@kernel.org> + * + * Based on drivers/spmi/spmi.c: + * Copyright (c) 2012-2015, The Linux Foundation. All rights reserved. + */ + +#include <linux/acpi.h> +#include <linux/errno.h> +#include <linux/idr.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/pm_domain.h> +#include <linux/pm_runtime.h> +#include <linux/sched.h> +#include <linux/serdev.h> +#include <linux/slab.h> +#include <linux/platform_data/x86/apple.h> + +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(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_simple_remove(&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, 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_release(struct device *dev, void *dr) +{ + serdev_device_close(*(struct serdev_device **)dr); +} + +int devm_serdev_device_open(struct device *dev, struct serdev_device *serdev) +{ + struct serdev_device **dr; + int ret; + + dr = devres_alloc(devm_serdev_device_release, sizeof(*dr), GFP_KERNEL); + if (!dr) + return -ENOMEM; + + ret = serdev_device_open(serdev); + if (ret) { + devres_free(dr); + return ret; + } + + *dr = serdev; + devres_add(dev, dr); + + return 0; +} +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 unsigned char *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. + */ +int serdev_device_write(struct serdev_device *serdev, + const unsigned char *buf, size_t count, + long timeout) +{ + struct serdev_controller *ctrl = serdev->ctrl; + int written = 0; + int 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 -ENOTSUPP; + + 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 -ENOTSUPP; + + 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 -ENOTSUPP; + + return ctrl->ops->set_tiocm(ctrl, set, clear); +} +EXPORT_SYMBOL_GPL(serdev_device_set_tiocm); + +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 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 + * @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 *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_simple_get(&ctrl_ida, 0, 0, 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->dev.of_node = parent->of_node; + 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_get_property(node, "compatible", NULL)) + continue; + + dev_dbg(&ctrl->dev, "adding child %pOF\n", node); + + serdev = serdev_device_alloc(ctrl); + if (!serdev) + continue; + + serdev->dev.of_node = 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 (ACPI_HANDLE(ctrl->dev.parent) != 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->dev.parent)) + 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->dev.parent, &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 <robh@kernel.org>"); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Serial attached device bus"); diff --git a/drivers/tty/serdev/serdev-ttyport.c b/drivers/tty/serdev/serdev-ttyport.c new file mode 100644 index 000000000..d367803e2 --- /dev/null +++ b/drivers/tty/serdev/serdev-ttyport.c @@ -0,0 +1,318 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <robh@kernel.org> + */ +#include <linux/kernel.h> +#include <linux/serdev.h> +#include <linux/tty.h> +#include <linux/tty_driver.h> +#include <linux/poll.h> + +#define SERPORT_ACTIVE 1 + +struct serport { + struct tty_port *port; + struct tty_struct *tty; + struct tty_driver *tty_drv; + int tty_idx; + unsigned long flags; +}; + +/* + * Callback functions from the tty port. + */ + +static int ttyport_receive_buf(struct tty_port *port, const unsigned char *cp, + const unsigned char *fp, size_t count) +{ + struct serdev_controller *ctrl = port->client_data; + struct serport *serport = serdev_controller_get_drvdata(ctrl); + int ret; + + if (!test_bit(SERPORT_ACTIVE, &serport->flags)) + return 0; + + ret = serdev_controller_receive_buf(ctrl, cp, count); + + dev_WARN_ONCE(&ctrl->dev, ret < 0 || ret > count, + "receive_buf returns %d (count = %zu)\n", + ret, count); + if (ret < 0) + return 0; + else if (ret > count) + return count; + + return ret; +} + +static void ttyport_write_wakeup(struct tty_port *port) +{ + struct serdev_controller *ctrl = port->client_data; + struct serport *serport = serdev_controller_get_drvdata(ctrl); + struct tty_struct *tty; + + tty = tty_port_tty_get(port); + if (!tty) + return; + + if (test_and_clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags) && + test_bit(SERPORT_ACTIVE, &serport->flags)) + serdev_controller_write_wakeup(ctrl); + + /* Wake up any tty_wait_until_sent() */ + wake_up_interruptible(&tty->write_wait); + + tty_kref_put(tty); +} + +static const struct tty_port_client_operations client_ops = { + .receive_buf = ttyport_receive_buf, + .write_wakeup = ttyport_write_wakeup, +}; + +/* + * Callback functions from the serdev core. + */ + +static int ttyport_write_buf(struct serdev_controller *ctrl, const unsigned char *data, size_t len) +{ + struct serport *serport = serdev_controller_get_drvdata(ctrl); + struct tty_struct *tty = serport->tty; + + if (!test_bit(SERPORT_ACTIVE, &serport->flags)) + return 0; + + set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); + return tty->ops->write(serport->tty, data, len); +} + +static void ttyport_write_flush(struct serdev_controller *ctrl) +{ + struct serport *serport = serdev_controller_get_drvdata(ctrl); + struct tty_struct *tty = serport->tty; + + tty_driver_flush_buffer(tty); +} + +static int ttyport_write_room(struct serdev_controller *ctrl) +{ + struct serport *serport = serdev_controller_get_drvdata(ctrl); + struct tty_struct *tty = serport->tty; + + return tty_write_room(tty); +} + +static int ttyport_open(struct serdev_controller *ctrl) +{ + struct serport *serport = serdev_controller_get_drvdata(ctrl); + struct tty_struct *tty; + struct ktermios ktermios; + int ret; + + tty = tty_init_dev(serport->tty_drv, serport->tty_idx); + if (IS_ERR(tty)) + return PTR_ERR(tty); + serport->tty = tty; + + if (!tty->ops->open || !tty->ops->close) { + ret = -ENODEV; + goto err_unlock; + } + + ret = tty->ops->open(serport->tty, NULL); + if (ret) + goto err_close; + + tty_unlock(serport->tty); + + /* Bring the UART into a known 8 bits no parity hw fc state */ + ktermios = tty->termios; + ktermios.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP | + INLCR | IGNCR | ICRNL | IXON); + ktermios.c_oflag &= ~OPOST; + ktermios.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN); + ktermios.c_cflag &= ~(CSIZE | PARENB); + ktermios.c_cflag |= CS8; + ktermios.c_cflag |= CRTSCTS; + /* Hangups are not supported so make sure to ignore carrier detect. */ + ktermios.c_cflag |= CLOCAL; + tty_set_termios(tty, &ktermios); + + set_bit(SERPORT_ACTIVE, &serport->flags); + + return 0; + +err_close: + tty->ops->close(tty, NULL); +err_unlock: + tty_unlock(tty); + tty_release_struct(tty, serport->tty_idx); + + return ret; +} + +static void ttyport_close(struct serdev_controller *ctrl) +{ + struct serport *serport = serdev_controller_get_drvdata(ctrl); + struct tty_struct *tty = serport->tty; + + clear_bit(SERPORT_ACTIVE, &serport->flags); + + tty_lock(tty); + if (tty->ops->close) + tty->ops->close(tty, NULL); + tty_unlock(tty); + + tty_release_struct(tty, serport->tty_idx); +} + +static unsigned int ttyport_set_baudrate(struct serdev_controller *ctrl, unsigned int speed) +{ + struct serport *serport = serdev_controller_get_drvdata(ctrl); + struct tty_struct *tty = serport->tty; + struct ktermios ktermios = tty->termios; + + ktermios.c_cflag &= ~CBAUD; + tty_termios_encode_baud_rate(&ktermios, speed, speed); + + /* tty_set_termios() return not checked as it is always 0 */ + tty_set_termios(tty, &ktermios); + return ktermios.c_ospeed; +} + +static void ttyport_set_flow_control(struct serdev_controller *ctrl, bool enable) +{ + struct serport *serport = serdev_controller_get_drvdata(ctrl); + struct tty_struct *tty = serport->tty; + struct ktermios ktermios = tty->termios; + + if (enable) + ktermios.c_cflag |= CRTSCTS; + else + ktermios.c_cflag &= ~CRTSCTS; + + tty_set_termios(tty, &ktermios); +} + +static int ttyport_set_parity(struct serdev_controller *ctrl, + enum serdev_parity parity) +{ + struct serport *serport = serdev_controller_get_drvdata(ctrl); + struct tty_struct *tty = serport->tty; + struct ktermios ktermios = tty->termios; + + ktermios.c_cflag &= ~(PARENB | PARODD | CMSPAR); + if (parity != SERDEV_PARITY_NONE) { + ktermios.c_cflag |= PARENB; + if (parity == SERDEV_PARITY_ODD) + ktermios.c_cflag |= PARODD; + } + + tty_set_termios(tty, &ktermios); + + if ((tty->termios.c_cflag & (PARENB | PARODD | CMSPAR)) != + (ktermios.c_cflag & (PARENB | PARODD | CMSPAR))) + return -EINVAL; + + return 0; +} + +static void ttyport_wait_until_sent(struct serdev_controller *ctrl, long timeout) +{ + struct serport *serport = serdev_controller_get_drvdata(ctrl); + struct tty_struct *tty = serport->tty; + + tty_wait_until_sent(tty, timeout); +} + +static int ttyport_get_tiocm(struct serdev_controller *ctrl) +{ + struct serport *serport = serdev_controller_get_drvdata(ctrl); + struct tty_struct *tty = serport->tty; + + if (!tty->ops->tiocmget) + return -ENOTSUPP; + + return tty->ops->tiocmget(tty); +} + +static int ttyport_set_tiocm(struct serdev_controller *ctrl, unsigned int set, unsigned int clear) +{ + struct serport *serport = serdev_controller_get_drvdata(ctrl); + struct tty_struct *tty = serport->tty; + + if (!tty->ops->tiocmset) + return -ENOTSUPP; + + return tty->ops->tiocmset(tty, set, clear); +} + +static const struct serdev_controller_ops ctrl_ops = { + .write_buf = ttyport_write_buf, + .write_flush = ttyport_write_flush, + .write_room = ttyport_write_room, + .open = ttyport_open, + .close = ttyport_close, + .set_flow_control = ttyport_set_flow_control, + .set_parity = ttyport_set_parity, + .set_baudrate = ttyport_set_baudrate, + .wait_until_sent = ttyport_wait_until_sent, + .get_tiocm = ttyport_get_tiocm, + .set_tiocm = ttyport_set_tiocm, +}; + +struct device *serdev_tty_port_register(struct tty_port *port, + struct device *parent, + struct tty_driver *drv, int idx) +{ + struct serdev_controller *ctrl; + struct serport *serport; + int ret; + + if (!port || !drv || !parent) + return ERR_PTR(-ENODEV); + + ctrl = serdev_controller_alloc(parent, sizeof(struct serport)); + if (!ctrl) + return ERR_PTR(-ENOMEM); + serport = serdev_controller_get_drvdata(ctrl); + + serport->port = port; + serport->tty_idx = idx; + serport->tty_drv = drv; + + ctrl->ops = &ctrl_ops; + + port->client_ops = &client_ops; + port->client_data = ctrl; + + ret = serdev_controller_add(ctrl); + if (ret) + goto err_reset_data; + + dev_info(&ctrl->dev, "tty port %s%d registered\n", drv->name, idx); + return &ctrl->dev; + +err_reset_data: + port->client_data = NULL; + port->client_ops = &tty_port_default_client_ops; + serdev_controller_put(ctrl); + + return ERR_PTR(ret); +} + +int serdev_tty_port_unregister(struct tty_port *port) +{ + struct serdev_controller *ctrl = port->client_data; + struct serport *serport = serdev_controller_get_drvdata(ctrl); + + if (!serport) + return -ENODEV; + + serdev_controller_remove(ctrl); + port->client_data = NULL; + port->client_ops = &tty_port_default_client_ops; + serdev_controller_put(ctrl); + + return 0; +} |