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linux-stable/include/linux/usb/serial.h
Johan Hovold 01fd45f676 USB: serial: add generic support for TIOCSSERIAL 
TIOCSSERIAL is a horrid, underspecified, legacy interface which for most
serial devices is only useful for setting the close_delay and
closing_wait parameters.

The closing_wait parameter determines how long to wait for the transfer
buffers to drain during close and the default timeout of 30 seconds may
not be sufficient at low line speeds. In other cases, when for example
flow is stopped, the default timeout may instead be too long.

Add generic support for TIOCSSERIAL and TIOCGSERIAL with handling of the
three common parameters close_delay, closing_wait and line for the
benefit of all USB serial drivers while still allowing drivers to
implement further functionality through the existing callbacks.

This currently includes a few drivers that report their base baud clock
rate even if that is really only of interest when setting custom
divisors through the deprecated ASYNC_SPD_CUST interface; an interface
which only the FTDI driver actually implements.

Some drivers have also been reporting back a fake UART type, something
which should no longer be needed and will be dropped by a follow-on
patch.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
2021-04-08 09:46:02 +02:00

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// SPDX-License-Identifier: GPL-2.0
/*
* USB Serial Converter stuff
*
* Copyright (C) 1999 - 2012
* Greg Kroah-Hartman (greg@kroah.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
*/
#ifndef __LINUX_USB_SERIAL_H
#define __LINUX_USB_SERIAL_H
#include <linux/kref.h>
#include <linux/mutex.h>
#include <linux/serial.h>
#include <linux/kfifo.h>
/* The maximum number of ports one device can grab at once */
#define MAX_NUM_PORTS 16
/* USB serial flags */
#define USB_SERIAL_WRITE_BUSY 0
#define USB_SERIAL_THROTTLED 1
/**
* usb_serial_port: structure for the specific ports of a device.
* @serial: pointer back to the struct usb_serial owner of this port.
* @port: pointer to the corresponding tty_port for this port.
* @lock: spinlock to grab when updating portions of this structure.
* @minor: the minor number of the port
* @port_number: the struct usb_serial port number of this port (starts at 0)
* @interrupt_in_buffer: pointer to the interrupt in buffer for this port.
* @interrupt_in_urb: pointer to the interrupt in struct urb for this port.
* @interrupt_in_endpointAddress: endpoint address for the interrupt in pipe
* for this port.
* @interrupt_out_buffer: pointer to the interrupt out buffer for this port.
* @interrupt_out_size: the size of the interrupt_out_buffer, in bytes.
* @interrupt_out_urb: pointer to the interrupt out struct urb for this port.
* @interrupt_out_endpointAddress: endpoint address for the interrupt out pipe
* for this port.
* @bulk_in_buffer: pointer to the bulk in buffer for this port.
* @bulk_in_size: the size of the bulk_in_buffer, in bytes.
* @read_urb: pointer to the bulk in struct urb for this port.
* @bulk_in_endpointAddress: endpoint address for the bulk in pipe for this
* port.
* @bulk_in_buffers: pointers to the bulk in buffers for this port
* @read_urbs: pointers to the bulk in urbs for this port
* @read_urbs_free: status bitmap the for bulk in urbs
* @bulk_out_buffer: pointer to the bulk out buffer for this port.
* @bulk_out_size: the size of the bulk_out_buffer, in bytes.
* @write_urb: pointer to the bulk out struct urb for this port.
* @write_fifo: kfifo used to buffer outgoing data
* @bulk_out_buffers: pointers to the bulk out buffers for this port
* @write_urbs: pointers to the bulk out urbs for this port
* @write_urbs_free: status bitmap the for bulk out urbs
* @icount: interrupt counters
* @tx_bytes: number of bytes currently in host stack queues
* @bulk_out_endpointAddress: endpoint address for the bulk out pipe for this
* port.
* @flags: usb serial port flags
* @work: work queue entry for the line discipline waking up.
* @dev: pointer to the serial device
*
* This structure is used by the usb-serial core and drivers for the specific
* ports of a device.
*/
struct usb_serial_port {
struct usb_serial *serial;
struct tty_port port;
spinlock_t lock;
u32 minor;
u8 port_number;
unsigned char *interrupt_in_buffer;
struct urb *interrupt_in_urb;
__u8 interrupt_in_endpointAddress;
unsigned char *interrupt_out_buffer;
int interrupt_out_size;
struct urb *interrupt_out_urb;
__u8 interrupt_out_endpointAddress;
unsigned char *bulk_in_buffer;
int bulk_in_size;
struct urb *read_urb;
__u8 bulk_in_endpointAddress;
unsigned char *bulk_in_buffers[2];
struct urb *read_urbs[2];
unsigned long read_urbs_free;
unsigned char *bulk_out_buffer;
int bulk_out_size;
struct urb *write_urb;
struct kfifo write_fifo;
unsigned char *bulk_out_buffers[2];
struct urb *write_urbs[2];
unsigned long write_urbs_free;
__u8 bulk_out_endpointAddress;
struct async_icount icount;
int tx_bytes;
unsigned long flags;
struct work_struct work;
unsigned long sysrq; /* sysrq timeout */
struct device dev;
};
#define to_usb_serial_port(d) container_of(d, struct usb_serial_port, dev)
/* get and set the port private data pointer helper functions */
static inline void *usb_get_serial_port_data(struct usb_serial_port *port)
{
return dev_get_drvdata(&port->dev);
}
static inline void usb_set_serial_port_data(struct usb_serial_port *port,
void *data)
{
dev_set_drvdata(&port->dev, data);
}
/**
* usb_serial - structure used by the usb-serial core for a device
* @dev: pointer to the struct usb_device for this device
* @type: pointer to the struct usb_serial_driver for this device
* @interface: pointer to the struct usb_interface for this device
* @sibling: pointer to the struct usb_interface of any sibling interface
* @suspend_count: number of suspended (sibling) interfaces
* @num_ports: the number of ports this device has
* @num_interrupt_in: number of interrupt in endpoints we have
* @num_interrupt_out: number of interrupt out endpoints we have
* @num_bulk_in: number of bulk in endpoints we have
* @num_bulk_out: number of bulk out endpoints we have
* @port: array of struct usb_serial_port structures for the different ports.
* @private: place to put any driver specific information that is needed. The
* usb-serial driver is required to manage this data, the usb-serial core
* will not touch this. Use usb_get_serial_data() and
* usb_set_serial_data() to access this.
*/
struct usb_serial {
struct usb_device *dev;
struct usb_serial_driver *type;
struct usb_interface *interface;
struct usb_interface *sibling;
unsigned int suspend_count;
unsigned char disconnected:1;
unsigned char attached:1;
unsigned char minors_reserved:1;
unsigned char num_ports;
unsigned char num_port_pointers;
unsigned char num_interrupt_in;
unsigned char num_interrupt_out;
unsigned char num_bulk_in;
unsigned char num_bulk_out;
struct usb_serial_port *port[MAX_NUM_PORTS];
struct kref kref;
struct mutex disc_mutex;
void *private;
};
#define to_usb_serial(d) container_of(d, struct usb_serial, kref)
/* get and set the serial private data pointer helper functions */
static inline void *usb_get_serial_data(struct usb_serial *serial)
{
return serial->private;
}
static inline void usb_set_serial_data(struct usb_serial *serial, void *data)
{
serial->private = data;
}
struct usb_serial_endpoints {
unsigned char num_bulk_in;
unsigned char num_bulk_out;
unsigned char num_interrupt_in;
unsigned char num_interrupt_out;
struct usb_endpoint_descriptor *bulk_in[MAX_NUM_PORTS];
struct usb_endpoint_descriptor *bulk_out[MAX_NUM_PORTS];
struct usb_endpoint_descriptor *interrupt_in[MAX_NUM_PORTS];
struct usb_endpoint_descriptor *interrupt_out[MAX_NUM_PORTS];
};
/**
* usb_serial_driver - describes a usb serial driver
* @description: pointer to a string that describes this driver. This string
* used in the syslog messages when a device is inserted or removed.
* @id_table: pointer to a list of usb_device_id structures that define all
* of the devices this structure can support.
* @num_ports: the number of different ports this device will have.
* @num_bulk_in: minimum number of bulk-in endpoints
* @num_bulk_out: minimum number of bulk-out endpoints
* @num_interrupt_in: minimum number of interrupt-in endpoints
* @num_interrupt_out: minimum number of interrupt-out endpoints
* @bulk_in_size: minimum number of bytes to allocate for bulk-in buffer
* (0 = end-point size)
* @bulk_out_size: bytes to allocate for bulk-out buffer (0 = end-point size)
* @calc_num_ports: pointer to a function to determine how many ports this
* device has dynamically. It can also be used to verify the number of
* endpoints or to modify the port-endpoint mapping. It will be called
* after the probe() callback is called, but before attach().
* @probe: pointer to the driver's probe function.
* This will be called when the device is inserted into the system,
* but before the device has been fully initialized by the usb_serial
* subsystem. Use this function to download any firmware to the device,
* or any other early initialization that might be needed.
* Return 0 to continue on with the initialization sequence. Anything
* else will abort it.
* @attach: pointer to the driver's attach function.
* This will be called when the struct usb_serial structure is fully
* set up. Do any local initialization of the device, or any private
* memory structure allocation at this point in time.
* @disconnect: pointer to the driver's disconnect function. This will be
* called when the device is unplugged or unbound from the driver.
* @release: pointer to the driver's release function. This will be called
* when the usb_serial data structure is about to be destroyed.
* @usb_driver: pointer to the struct usb_driver that controls this
* device. This is necessary to allow dynamic ids to be added to
* the driver from sysfs.
*
* This structure is defines a USB Serial driver. It provides all of
* the information that the USB serial core code needs. If the function
* pointers are defined, then the USB serial core code will call them when
* the corresponding tty port functions are called. If they are not
* called, the generic serial function will be used instead.
*
* The driver.owner field should be set to the module owner of this driver.
* The driver.name field should be set to the name of this driver (remember
* it will show up in sysfs, so it needs to be short and to the point.
* Using the module name is a good idea.)
*/
struct usb_serial_driver {
const char *description;
const struct usb_device_id *id_table;
struct list_head driver_list;
struct device_driver driver;
struct usb_driver *usb_driver;
struct usb_dynids dynids;
unsigned char num_ports;
unsigned char num_bulk_in;
unsigned char num_bulk_out;
unsigned char num_interrupt_in;
unsigned char num_interrupt_out;
size_t bulk_in_size;
size_t bulk_out_size;
int (*probe)(struct usb_serial *serial, const struct usb_device_id *id);
int (*attach)(struct usb_serial *serial);
int (*calc_num_ports)(struct usb_serial *serial,
struct usb_serial_endpoints *epds);
void (*disconnect)(struct usb_serial *serial);
void (*release)(struct usb_serial *serial);
int (*port_probe)(struct usb_serial_port *port);
void (*port_remove)(struct usb_serial_port *port);
int (*suspend)(struct usb_serial *serial, pm_message_t message);
int (*resume)(struct usb_serial *serial);
int (*reset_resume)(struct usb_serial *serial);
/* serial function calls */
/* Called by console and by the tty layer */
int (*open)(struct tty_struct *tty, struct usb_serial_port *port);
void (*close)(struct usb_serial_port *port);
int (*write)(struct tty_struct *tty, struct usb_serial_port *port,
const unsigned char *buf, int count);
/* Called only by the tty layer */
int (*write_room)(struct tty_struct *tty);
int (*ioctl)(struct tty_struct *tty,
unsigned int cmd, unsigned long arg);
void (*get_serial)(struct tty_struct *tty, struct serial_struct *ss);
int (*set_serial)(struct tty_struct *tty, struct serial_struct *ss);
void (*set_termios)(struct tty_struct *tty,
struct usb_serial_port *port, struct ktermios *old);
void (*break_ctl)(struct tty_struct *tty, int break_state);
int (*chars_in_buffer)(struct tty_struct *tty);
void (*wait_until_sent)(struct tty_struct *tty, long timeout);
bool (*tx_empty)(struct usb_serial_port *port);
void (*throttle)(struct tty_struct *tty);
void (*unthrottle)(struct tty_struct *tty);
int (*tiocmget)(struct tty_struct *tty);
int (*tiocmset)(struct tty_struct *tty,
unsigned int set, unsigned int clear);
int (*tiocmiwait)(struct tty_struct *tty, unsigned long arg);
int (*get_icount)(struct tty_struct *tty,
struct serial_icounter_struct *icount);
/* Called by the tty layer for port level work. There may or may not
be an attached tty at this point */
void (*dtr_rts)(struct usb_serial_port *port, int on);
int (*carrier_raised)(struct usb_serial_port *port);
/* Called by the usb serial hooks to allow the user to rework the
termios state */
void (*init_termios)(struct tty_struct *tty);
/* USB events */
void (*read_int_callback)(struct urb *urb);
void (*write_int_callback)(struct urb *urb);
void (*read_bulk_callback)(struct urb *urb);
void (*write_bulk_callback)(struct urb *urb);
/* Called by the generic read bulk callback */
void (*process_read_urb)(struct urb *urb);
/* Called by the generic write implementation */
int (*prepare_write_buffer)(struct usb_serial_port *port,
void *dest, size_t size);
};
#define to_usb_serial_driver(d) \
container_of(d, struct usb_serial_driver, driver)
int usb_serial_register_drivers(struct usb_serial_driver *const serial_drivers[],
const char *name, const struct usb_device_id *id_table);
void usb_serial_deregister_drivers(struct usb_serial_driver *const serial_drivers[]);
void usb_serial_port_softint(struct usb_serial_port *port);
int usb_serial_suspend(struct usb_interface *intf, pm_message_t message);
int usb_serial_resume(struct usb_interface *intf);
/* USB Serial console functions */
#ifdef CONFIG_USB_SERIAL_CONSOLE
void usb_serial_console_init(int minor);
void usb_serial_console_exit(void);
void usb_serial_console_disconnect(struct usb_serial *serial);
#else
static inline void usb_serial_console_init(int minor) { }
static inline void usb_serial_console_exit(void) { }
static inline void usb_serial_console_disconnect(struct usb_serial *serial) {}
#endif
/* Functions needed by other parts of the usbserial core */
struct usb_serial_port *usb_serial_port_get_by_minor(unsigned int minor);
void usb_serial_put(struct usb_serial *serial);
int usb_serial_claim_interface(struct usb_serial *serial, struct usb_interface *intf);
int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port);
int usb_serial_generic_write_start(struct usb_serial_port *port, gfp_t mem_flags);
int usb_serial_generic_write(struct tty_struct *tty, struct usb_serial_port *port,
const unsigned char *buf, int count);
void usb_serial_generic_close(struct usb_serial_port *port);
int usb_serial_generic_resume(struct usb_serial *serial);
int usb_serial_generic_write_room(struct tty_struct *tty);
int usb_serial_generic_chars_in_buffer(struct tty_struct *tty);
void usb_serial_generic_wait_until_sent(struct tty_struct *tty, long timeout);
void usb_serial_generic_read_bulk_callback(struct urb *urb);
void usb_serial_generic_write_bulk_callback(struct urb *urb);
void usb_serial_generic_throttle(struct tty_struct *tty);
void usb_serial_generic_unthrottle(struct tty_struct *tty);
int usb_serial_generic_tiocmiwait(struct tty_struct *tty, unsigned long arg);
int usb_serial_generic_get_icount(struct tty_struct *tty, struct serial_icounter_struct *icount);
int usb_serial_generic_register(void);
void usb_serial_generic_deregister(void);
int usb_serial_generic_submit_read_urbs(struct usb_serial_port *port, gfp_t mem_flags);
void usb_serial_generic_process_read_urb(struct urb *urb);
int usb_serial_generic_prepare_write_buffer(struct usb_serial_port *port, void *dest, size_t size);
#if defined(CONFIG_USB_SERIAL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch);
int usb_serial_handle_break(struct usb_serial_port *port);
#else
static inline int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
{
return 0;
}
static inline int usb_serial_handle_break(struct usb_serial_port *port)
{
return 0;
}
#endif
void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port,
struct tty_struct *tty, unsigned int status);
int usb_serial_bus_register(struct usb_serial_driver *device);
void usb_serial_bus_deregister(struct usb_serial_driver *device);
extern struct bus_type usb_serial_bus_type;
extern struct tty_driver *usb_serial_tty_driver;
static inline void usb_serial_debug_data(struct device *dev,
const char *function, int size,
const unsigned char *data)
{
dev_dbg(dev, "%s - length = %d, data = %*ph\n",
function, size, size, data);
}
/*
* Macro for reporting errors in write path to avoid inifinite loop
* when port is used as a console.
*/
#define dev_err_console(usport, fmt, ...) \
do { \
static bool __print_once; \
struct usb_serial_port *__port = (usport); \
\
if (!__port->port.console || !__print_once) { \
__print_once = true; \
dev_err(&__port->dev, fmt, ##__VA_ARGS__); \
} \
} while (0)
/*
* module_usb_serial_driver() - Helper macro for registering a USB Serial driver
* @__serial_drivers: list of usb_serial drivers to register
* @__ids: all device ids that @__serial_drivers bind to
*
* Helper macro for USB serial drivers which do not do anything special
* in module init/exit. This eliminates a lot of boilerplate. Each
* module may only use this macro once, and calling it replaces
* module_init() and module_exit()
*
*/
#define usb_serial_module_driver(__name, __serial_drivers, __ids) \
static int __init usb_serial_module_init(void) \
{ \
return usb_serial_register_drivers(__serial_drivers, \
__name, __ids); \
} \
module_init(usb_serial_module_init); \
static void __exit usb_serial_module_exit(void) \
{ \
usb_serial_deregister_drivers(__serial_drivers); \
} \
module_exit(usb_serial_module_exit);
#define module_usb_serial_driver(__serial_drivers, __ids) \
usb_serial_module_driver(KBUILD_MODNAME, __serial_drivers, __ids)
#endif /* __LINUX_USB_SERIAL_H */
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