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-rw-r--r--drivers/tty/serdev/Kconfig25
-rw-r--r--drivers/tty/serdev/Makefile6
-rw-r--r--drivers/tty/serdev/core.c874
-rw-r--r--drivers/tty/serdev/serdev-ttyport.c318
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;
+}