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Diffstat (limited to 'include/linux/serdev.h')
-rw-r--r-- | include/linux/serdev.h | 330 |
1 files changed, 330 insertions, 0 deletions
diff --git a/include/linux/serdev.h b/include/linux/serdev.h new file mode 100644 index 000000000..9f14f9c12 --- /dev/null +++ b/include/linux/serdev.h @@ -0,0 +1,330 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <robh@kernel.org> + */ +#ifndef _LINUX_SERDEV_H +#define _LINUX_SERDEV_H + +#include <linux/types.h> +#include <linux/device.h> +#include <linux/termios.h> +#include <linux/delay.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; + * returns number of bytes accepted; may sleep. + * @write_wakeup: Function called when ready to transmit more data; must + * not sleep. + */ +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. + * @write_comp Completion used by serdev_device_write() internally + * @write_lock Lock to serialize access when writing data + */ +struct serdev_device { + struct device dev; + int nr; + struct serdev_controller *ctrl; + const struct serdev_device_ops *ops; + struct completion write_comp; + struct mutex write_lock; +}; + +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); +} + +enum serdev_parity { + SERDEV_PARITY_NONE, + SERDEV_PARITY_EVEN, + SERDEV_PARITY_ODD, +}; + +/* + * 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); + int (*set_parity)(struct serdev_controller *, enum serdev_parity); + unsigned int (*set_baudrate)(struct serdev_controller *, unsigned int); + void (*wait_until_sent)(struct serdev_controller *, long); + int (*get_tiocm)(struct serdev_controller *); + int (*set_tiocm)(struct serdev_controller *, unsigned int, 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(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 0; + + return serdev->ops->receive_buf(serdev, data, count); +} + +#if IS_ENABLED(CONFIG_SERIAL_DEV_BUS) + +int serdev_device_open(struct serdev_device *); +void serdev_device_close(struct serdev_device *); +int devm_serdev_device_open(struct device *, 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_wait_until_sent(struct serdev_device *, long); +int serdev_device_get_tiocm(struct serdev_device *); +int serdev_device_set_tiocm(struct serdev_device *, int, int); +void serdev_device_write_wakeup(struct serdev_device *); +int serdev_device_write(struct serdev_device *, const unsigned char *, size_t, long); +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 *serdev, + const unsigned char *buf, + size_t count) +{ + return -ENODEV; +} +static inline void serdev_device_wait_until_sent(struct serdev_device *sdev, long timeout) {} +static inline int serdev_device_get_tiocm(struct serdev_device *serdev) +{ + return -ENOTSUPP; +} +static inline int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear) +{ + return -ENOTSUPP; +} +static inline int serdev_device_write(struct serdev_device *sdev, const unsigned char *buf, + size_t count, unsigned long timeout) +{ + 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 */ + +static inline bool serdev_device_get_cts(struct serdev_device *serdev) +{ + int status = serdev_device_get_tiocm(serdev); + return !!(status & TIOCM_CTS); +} + +static inline int serdev_device_wait_for_cts(struct serdev_device *serdev, bool state, int timeout_ms) +{ + unsigned long timeout; + bool signal; + + timeout = jiffies + msecs_to_jiffies(timeout_ms); + while (time_is_after_jiffies(timeout)) { + signal = serdev_device_get_cts(serdev); + if (signal == state) + return 0; + usleep_range(1000, 2000); + } + + return -ETIMEDOUT; +} + +static inline int serdev_device_set_rts(struct serdev_device *serdev, bool enable) +{ + if (enable) + return serdev_device_set_tiocm(serdev, TIOCM_RTS, 0); + else + return serdev_device_set_tiocm(serdev, 0, TIOCM_RTS); +} + +int serdev_device_set_parity(struct serdev_device *serdev, + enum serdev_parity parity); + +/* + * serdev hooks into TTY core + */ +struct tty_port; +struct tty_driver; + +#ifdef CONFIG_SERIAL_DEV_CTRL_TTYPORT +struct device *serdev_tty_port_register(struct tty_port *port, + struct device *parent, + struct tty_driver *drv, int idx); +int serdev_tty_port_unregister(struct tty_port *port); +#else +static inline struct device *serdev_tty_port_register(struct tty_port *port, + struct device *parent, + struct tty_driver *drv, int idx) +{ + return ERR_PTR(-ENODEV); +} +static inline int serdev_tty_port_unregister(struct tty_port *port) +{ + return -ENODEV; +} +#endif /* CONFIG_SERIAL_DEV_CTRL_TTYPORT */ + +#endif /*_LINUX_SERDEV_H */ |