@@ -10831,6 +10831,14 @@ S: Maintained
F: Documentation/devicetree/bindings/serial/
F: drivers/tty/serial/
+SERIAL DEVICE BUS
+M: Rob Herring <robh@kernel.org>
+L: linux-serial@vger.kernel.org
+S: Maintained
+F: Documentation/devicetree/bindings/serial/slave-device.txt
+F: drivers/tty/serdev/
+F: include/linux/serdev.h
+
SERIAL IR RECEIVER
M: Sean Young <sean@mess.org>
L: linux-media@vger.kernel.org
@@ -46,6 +46,7 @@ config SGI_MBCS
say Y or M here, otherwise say N.
source "drivers/tty/serial/Kconfig"
+source "drivers/tty/serdev/Kconfig"
config TTY_PRINTK
tristate "TTY driver to output user messages via printk"
@@ -13,6 +13,7 @@ obj-$(CONFIG_R3964) += n_r3964.o
obj-y += vt/
obj-$(CONFIG_HVC_DRIVER) += hvc/
obj-y += serial/
+obj-$(CONFIG_SERIAL_DEV_BUS) += serdev/
# tty drivers
obj-$(CONFIG_AMIGA_BUILTIN_SERIAL) += amiserial.o
new file mode 100644
@@ -0,0 +1,8 @@
+#
+# Serial bus device driver configuration
+#
+menuconfig SERIAL_DEV_BUS
+ tristate "Serial device bus"
+ help
+ Core support for devices connected via a serial port.
+
new file mode 100644
@@ -0,0 +1,3 @@
+serdev-objs := core.o
+
+obj-$(CONFIG_SERIAL_DEV_BUS) += serdev.o
new file mode 100644
@@ -0,0 +1,421 @@
+/*
+ * 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.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#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/serdev.h>
+#include <linux/slab.h>
+
+static bool is_registered;
+static DEFINE_IDA(ctrl_ida);
+
+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 = {
+ .release = serdev_device_release,
+};
+
+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)
+{
+ /* TODO: ACPI and platform matching */
+ return of_driver_match_device(dev, drv);
+}
+
+static int serdev_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+ /* TODO: ACPI and platform modalias */
+ return of_device_uevent_modalias(dev, env);
+}
+
+/**
+ * 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 device *parent = serdev->dev.parent;
+ int err;
+
+ dev_set_name(&serdev->dev, "%s-%d", dev_name(parent), serdev->nr);
+
+ err = device_add(&serdev->dev);
+ if (err < 0) {
+ dev_err(&serdev->dev, "Can't add %s, status %d\n",
+ dev_name(&serdev->dev), err);
+ goto err_device_add;
+ }
+
+ dev_dbg(&serdev->dev, "device %s registered\n", dev_name(&serdev->dev));
+
+err_device_add:
+ 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)
+{
+ device_unregister(&serdev->dev);
+}
+EXPORT_SYMBOL_GPL(serdev_device_remove);
+
+int serdev_device_open(struct serdev_device *serdev)
+{
+ struct serdev_controller *ctrl = serdev->ctrl;
+
+ if (!ctrl || !ctrl->ops->open)
+ return -EINVAL;
+
+ return ctrl->ops->open(ctrl);
+}
+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;
+
+ ctrl->ops->close(ctrl);
+}
+EXPORT_SYMBOL_GPL(serdev_device_close);
+
+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);
+
+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);
+
+static int serdev_drv_probe(struct device *dev)
+{
+ const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);
+
+ return sdrv->probe(to_serdev_device(dev));
+}
+
+static int serdev_drv_remove(struct device *dev)
+{
+ const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);
+
+ sdrv->remove(to_serdev_device(dev));
+ return 0;
+}
+
+static ssize_t modalias_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ ssize_t len = of_device_get_modalias(dev, buf, PAGE_SIZE - 2);
+ buf[len] = '\n';
+ buf[len+1] = 0;
+ return len+1;
+}
+
+static struct device_attribute serdev_device_attrs[] = {
+ __ATTR_RO(modalias),
+ __ATTR_NULL
+};
+
+static struct bus_type serdev_bus_type = {
+ .name = "serial",
+ .match = serdev_device_match,
+ .probe = serdev_drv_probe,
+ .remove = serdev_drv_remove,
+ .uevent = serdev_uevent,
+ .dev_attrs = serdev_device_attrs,
+};
+
+/**
+ * serdev_controller_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;
+ ctrl->serdev = serdev;
+ device_initialize(&serdev->dev);
+ serdev->dev.parent = &ctrl->dev;
+ serdev->dev.bus = &serdev_bus_type;
+ serdev->dev.type = &serdev_device_type;
+ 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;
+
+ 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]);
+
+ id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL);
+ if (id < 0) {
+ dev_err(parent,
+ "unable to allocate serdev controller identifier.\n");
+ serdev_controller_put(ctrl);
+ return NULL;
+ }
+
+ ctrl->nr = id;
+ dev_set_name(&ctrl->dev, "serial%d", id);
+
+ dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id);
+ return ctrl;
+}
+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 %s\n", node->full_name);
+
+ 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 %d\n", err);
+ serdev_device_put(serdev);
+ } else
+ found = true;
+ }
+ if (!found)
+ return -ENODEV;
+
+ return 0;
+}
+
+/**
+ * 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;
+
+ /* Can't register until after driver model init */
+ if (WARN_ON(!is_registered))
+ return -EAGAIN;
+
+ ret = device_add(&ctrl->dev);
+ if (ret)
+ return ret;
+
+ ret = of_serdev_register_devices(ctrl);
+ if (ret)
+ goto out_dev_del;
+
+ dev_dbg(&ctrl->dev, "serdev%d registered: dev:%p\n",
+ ctrl->nr, &ctrl->dev);
+ return 0;
+
+out_dev_del:
+ 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)
+{
+ int dummy;
+
+ if (!ctrl)
+ return;
+
+ dummy = device_for_each_child(&ctrl->dev, NULL,
+ serdev_remove_device);
+ device_del(&ctrl->dev);
+}
+EXPORT_SYMBOL_GPL(serdev_controller_remove);
+
+/**
+ * serdev_driver_register() - Register client driver with serdev core
+ * @sdrv: client driver to be associated with client-device.
+ *
+ * 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);
+}
+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");
new file mode 100644
@@ -0,0 +1,241 @@
+/*
+ * Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <robh@kernel.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+#ifndef _LINUX_SERDEV_H
+#define _LINUX_SERDEV_H
+
+#include <linux/types.h>
+#include <linux/device.h>
+
+struct serdev_controller;
+struct serdev_device;
+
+/*
+ * serdev device structures
+ */
+
+/**
+ * struct serdev_device_ops - Callback operations for a serdev device
+ * @receive_buf: Function called with data received from device.
+ * @write_wakeup: Function called when ready to transmit more data.
+ */
+struct serdev_device_ops {
+ int (*receive_buf)(struct serdev_device *, const unsigned char *, size_t);
+ void (*write_wakeup)(struct serdev_device *);
+};
+
+/**
+ * struct serdev_device - Basic representation of an serdev device
+ * @dev: Driver model representation of the device.
+ * @nr: Device number on serdev bus.
+ * @ctrl: serdev controller managing this device.
+ * @ops: Device operations.
+ */
+struct serdev_device {
+ struct device dev;
+ int nr;
+ struct serdev_controller *ctrl;
+ const struct serdev_device_ops *ops;
+};
+
+static inline struct serdev_device *to_serdev_device(struct device *d)
+{
+ return container_of(d, struct serdev_device, dev);
+}
+
+/**
+ * struct serdev_device_driver - serdev slave device driver
+ * @driver: serdev device drivers should initialize name field of this
+ * structure.
+ * @probe: binds this driver to a serdev device.
+ * @remove: unbinds this driver from the serdev device.
+ */
+struct serdev_device_driver {
+ struct device_driver driver;
+ int (*probe)(struct serdev_device *);
+ void (*remove)(struct serdev_device *);
+};
+
+static inline struct serdev_device_driver *to_serdev_device_driver(struct device_driver *d)
+{
+ return container_of(d, struct serdev_device_driver, driver);
+}
+
+/*
+ * serdev controller structures
+ */
+struct serdev_controller_ops {
+ int (*write_buf)(struct serdev_controller *, const unsigned char *, size_t);
+ void (*write_flush)(struct serdev_controller *);
+ int (*write_room)(struct serdev_controller *);
+ int (*open)(struct serdev_controller *);
+ void (*close)(struct serdev_controller *);
+ void (*set_flow_control)(struct serdev_controller *, bool);
+ unsigned int (*set_baudrate)(struct serdev_controller *, unsigned int);
+};
+
+/**
+ * struct serdev_controller - interface to the serdev controller
+ * @dev: Driver model representation of the device.
+ * @nr: number identifier for this controller/bus.
+ * @serdev: Pointer to slave device for this controller.
+ * @ops: Controller operations.
+ */
+struct serdev_controller {
+ struct device dev;
+ unsigned int nr;
+ struct serdev_device *serdev;
+ const struct serdev_controller_ops *ops;
+};
+
+static inline struct serdev_controller *to_serdev_controller(struct device *d)
+{
+ return container_of(d, struct serdev_controller, dev);
+}
+
+static inline void *serdev_device_get_drvdata(const struct serdev_device *serdev)
+{
+ return dev_get_drvdata(&serdev->dev);
+}
+
+static inline void serdev_device_set_drvdata(struct serdev_device *serdev, void *data)
+{
+ dev_set_drvdata(&serdev->dev, data);
+}
+
+/**
+ * serdev_device_put() - decrement serdev device refcount
+ * @serdev serdev device.
+ */
+static inline void serdev_device_put(struct serdev_device *serdev)
+{
+ if (serdev)
+ put_device(&serdev->dev);
+}
+
+static inline void serdev_device_set_client_ops(struct serdev_device *serdev,
+ const struct serdev_device_ops *ops)
+{
+ serdev->ops = ops;
+}
+
+static inline
+void *serdev_controller_get_drvdata(const struct serdev_controller *ctrl)
+{
+ return ctrl ? dev_get_drvdata(&ctrl->dev) : NULL;
+}
+
+static inline void serdev_controller_set_drvdata(struct serdev_controller *ctrl,
+ void *data)
+{
+ dev_set_drvdata(&ctrl->dev, data);
+}
+
+/**
+ * serdev_controller_put() - decrement controller refcount
+ * @ctrl serdev controller.
+ */
+static inline void serdev_controller_put(struct serdev_controller *ctrl)
+{
+ if (ctrl)
+ put_device(&ctrl->dev);
+}
+
+struct serdev_device *serdev_device_alloc(struct serdev_controller *);
+int serdev_device_add(struct serdev_device *);
+void serdev_device_remove(struct serdev_device *);
+
+struct serdev_controller *serdev_controller_alloc(struct device *, size_t);
+int serdev_controller_add(struct serdev_controller *);
+void serdev_controller_remove(struct serdev_controller *);
+
+static inline void serdev_controller_write_wakeup(struct serdev_controller *ctrl)
+{
+ struct serdev_device *serdev = ctrl->serdev;
+
+ if (!serdev || !serdev->ops->write_wakeup)
+ return;
+
+ serdev->ops->write_wakeup(ctrl->serdev);
+}
+
+static inline int serdev_controller_receive_buf(struct serdev_controller *ctrl,
+ const unsigned char *data,
+ size_t count)
+{
+ struct serdev_device *serdev = ctrl->serdev;
+
+ if (!serdev || !serdev->ops->receive_buf)
+ return -EINVAL;
+
+ return serdev->ops->receive_buf(ctrl->serdev, data, count);
+}
+
+#if IS_ENABLED(CONFIG_SERIAL_DEV_BUS)
+
+int serdev_device_open(struct serdev_device *);
+void serdev_device_close(struct serdev_device *);
+unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int);
+void serdev_device_set_flow_control(struct serdev_device *, bool);
+int serdev_device_write_buf(struct serdev_device *, const unsigned char *, size_t);
+void serdev_device_write_flush(struct serdev_device *);
+int serdev_device_write_room(struct serdev_device *);
+
+/*
+ * serdev device driver functions
+ */
+int __serdev_device_driver_register(struct serdev_device_driver *, struct module *);
+#define serdev_device_driver_register(sdrv) \
+ __serdev_device_driver_register(sdrv, THIS_MODULE)
+
+/**
+ * serdev_device_driver_unregister() - unregister an serdev client driver
+ * @sdrv: the driver to unregister
+ */
+static inline void serdev_device_driver_unregister(struct serdev_device_driver *sdrv)
+{
+ if (sdrv)
+ driver_unregister(&sdrv->driver);
+}
+
+#define module_serdev_device_driver(__serdev_device_driver) \
+ module_driver(__serdev_device_driver, serdev_device_driver_register, \
+ serdev_device_driver_unregister)
+
+#else
+
+static inline int serdev_device_open(struct serdev_device *sdev)
+{
+ return -ENODEV;
+}
+static inline void serdev_device_close(struct serdev_device *sdev) {}
+static inline unsigned int serdev_device_set_baudrate(struct serdev_device *sdev, unsigned int baudrate)
+{
+ return 0;
+}
+static inline void serdev_device_set_flow_control(struct serdev_device *sdev, bool enable) {}
+static inline int serdev_device_write_buf(struct serdev_device *sdev, const unsigned char *buf, size_t count)
+{
+ return -ENODEV;
+}
+static inline void serdev_device_write_flush(struct serdev_device *sdev) {}
+static inline int serdev_device_write_room(struct serdev_device *sdev)
+{
+ return 0;
+}
+
+#define serdev_device_driver_register(x)
+#define serdev_device_driver_unregister(x)
+
+#endif /* CONFIG_SERIAL_DEV_BUS */
+
+#endif /*_LINUX_SERDEV_H */