diff options
| -rw-r--r-- | MAINTAINERS | 8 | ||||
| -rw-r--r-- | drivers/char/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/tty/Makefile | 1 | ||||
| -rw-r--r-- | drivers/tty/serdev/Kconfig | 8 | ||||
| -rw-r--r-- | drivers/tty/serdev/Makefile | 3 | ||||
| -rw-r--r-- | drivers/tty/serdev/core.c | 421 | ||||
| -rw-r--r-- | include/linux/serdev.h | 241 |
7 files changed, 683 insertions, 0 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index c36976d3bd1a..90db2b5d418c 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -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 diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig index fde005ef9d36..db8f74bbaf3e 100644 --- a/drivers/char/Kconfig +++ b/drivers/char/Kconfig @@ -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" diff --git a/drivers/tty/Makefile b/drivers/tty/Makefile index 5817e2397463..b95bed92da9f 100644 --- a/drivers/tty/Makefile +++ b/drivers/tty/Makefile @@ -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 diff --git a/drivers/tty/serdev/Kconfig b/drivers/tty/serdev/Kconfig new file mode 100644 index 000000000000..3b6ecd187bef --- /dev/null +++ b/drivers/tty/serdev/Kconfig @@ -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. + diff --git a/drivers/tty/serdev/Makefile b/drivers/tty/serdev/Makefile new file mode 100644 index 000000000000..01a9b62183f4 --- /dev/null +++ b/drivers/tty/serdev/Makefile @@ -0,0 +1,3 @@ +serdev-objs := core.o + +obj-$(CONFIG_SERIAL_DEV_BUS) += serdev.o diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c new file mode 100644 index 000000000000..f4c6c90add78 --- /dev/null +++ b/drivers/tty/serdev/core.c @@ -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"); diff --git a/include/linux/serdev.h b/include/linux/serdev.h new file mode 100644 index 000000000000..3ac26c1a8aab --- /dev/null +++ b/include/linux/serdev.h @@ -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 */ |