diff options
Diffstat (limited to 'drivers/usb/serial/generic.c')
| -rw-r--r-- | drivers/usb/serial/generic.c | 628 |
1 files changed, 628 insertions, 0 deletions
diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c new file mode 100644 index 000000000..54e170dd3 --- /dev/null +++ b/drivers/usb/serial/generic.c @@ -0,0 +1,628 @@ +/* + * USB Serial Converter Generic functions + * + * Copyright (C) 2010 - 2013 Johan Hovold (jhovold@gmail.com) + * Copyright (C) 1999 - 2002 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 version + * 2 as published by the Free Software Foundation. + */ + +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/slab.h> +#include <linux/sysrq.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/usb.h> +#include <linux/usb/serial.h> +#include <linux/uaccess.h> +#include <linux/kfifo.h> +#include <linux/serial.h> + +#ifdef CONFIG_USB_SERIAL_GENERIC + +static __u16 vendor = 0x05f9; +static __u16 product = 0xffff; + +module_param(vendor, ushort, 0); +MODULE_PARM_DESC(vendor, "User specified USB idVendor"); + +module_param(product, ushort, 0); +MODULE_PARM_DESC(product, "User specified USB idProduct"); + +static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */ + +struct usb_serial_driver usb_serial_generic_device = { + .driver = { + .owner = THIS_MODULE, + .name = "generic", + }, + .id_table = generic_device_ids, + .num_ports = 1, + .throttle = usb_serial_generic_throttle, + .unthrottle = usb_serial_generic_unthrottle, + .resume = usb_serial_generic_resume, +}; + +static struct usb_serial_driver * const serial_drivers[] = { + &usb_serial_generic_device, NULL +}; + +#endif + +int usb_serial_generic_register(void) +{ + int retval = 0; + +#ifdef CONFIG_USB_SERIAL_GENERIC + generic_device_ids[0].idVendor = vendor; + generic_device_ids[0].idProduct = product; + generic_device_ids[0].match_flags = + USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT; + + retval = usb_serial_register_drivers(serial_drivers, + "usbserial_generic", generic_device_ids); +#endif + return retval; +} + +void usb_serial_generic_deregister(void) +{ +#ifdef CONFIG_USB_SERIAL_GENERIC + usb_serial_deregister_drivers(serial_drivers); +#endif +} + +int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port) +{ + int result = 0; + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + port->throttled = 0; + port->throttle_req = 0; + spin_unlock_irqrestore(&port->lock, flags); + + if (port->bulk_in_size) + result = usb_serial_generic_submit_read_urbs(port, GFP_KERNEL); + + return result; +} +EXPORT_SYMBOL_GPL(usb_serial_generic_open); + +void usb_serial_generic_close(struct usb_serial_port *port) +{ + unsigned long flags; + int i; + + if (port->bulk_out_size) { + for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i) + usb_kill_urb(port->write_urbs[i]); + + spin_lock_irqsave(&port->lock, flags); + kfifo_reset_out(&port->write_fifo); + spin_unlock_irqrestore(&port->lock, flags); + } + if (port->bulk_in_size) { + for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) + usb_kill_urb(port->read_urbs[i]); + } +} +EXPORT_SYMBOL_GPL(usb_serial_generic_close); + +int usb_serial_generic_prepare_write_buffer(struct usb_serial_port *port, + void *dest, size_t size) +{ + return kfifo_out_locked(&port->write_fifo, dest, size, &port->lock); +} + +/** + * usb_serial_generic_write_start - start writing buffered data + * @port: usb-serial port + * @mem_flags: flags to use for memory allocations + * + * Serialised using USB_SERIAL_WRITE_BUSY flag. + * + * Return: Zero on success or if busy, otherwise a negative errno value. + */ +int usb_serial_generic_write_start(struct usb_serial_port *port, + gfp_t mem_flags) +{ + struct urb *urb; + int count, result; + unsigned long flags; + int i; + + if (test_and_set_bit_lock(USB_SERIAL_WRITE_BUSY, &port->flags)) + return 0; +retry: + spin_lock_irqsave(&port->lock, flags); + if (!port->write_urbs_free || !kfifo_len(&port->write_fifo)) { + clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags); + spin_unlock_irqrestore(&port->lock, flags); + return 0; + } + i = (int)find_first_bit(&port->write_urbs_free, + ARRAY_SIZE(port->write_urbs)); + spin_unlock_irqrestore(&port->lock, flags); + + urb = port->write_urbs[i]; + count = port->serial->type->prepare_write_buffer(port, + urb->transfer_buffer, + port->bulk_out_size); + urb->transfer_buffer_length = count; + usb_serial_debug_data(&port->dev, __func__, count, urb->transfer_buffer); + spin_lock_irqsave(&port->lock, flags); + port->tx_bytes += count; + spin_unlock_irqrestore(&port->lock, flags); + + clear_bit(i, &port->write_urbs_free); + result = usb_submit_urb(urb, mem_flags); + if (result) { + dev_err_console(port, "%s - error submitting urb: %d\n", + __func__, result); + set_bit(i, &port->write_urbs_free); + spin_lock_irqsave(&port->lock, flags); + port->tx_bytes -= count; + spin_unlock_irqrestore(&port->lock, flags); + + clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags); + return result; + } + + goto retry; /* try sending off another urb */ +} +EXPORT_SYMBOL_GPL(usb_serial_generic_write_start); + +/** + * usb_serial_generic_write - generic write function + * @tty: tty for the port + * @port: usb-serial port + * @buf: data to write + * @count: number of bytes to write + * + * Return: The number of characters buffered, which may be anything from + * zero to @count, or a negative errno value. + */ +int usb_serial_generic_write(struct tty_struct *tty, + struct usb_serial_port *port, const unsigned char *buf, int count) +{ + int result; + + if (!port->bulk_out_size) + return -ENODEV; + + if (!count) + return 0; + + count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock); + result = usb_serial_generic_write_start(port, GFP_ATOMIC); + if (result) + return result; + + return count; +} +EXPORT_SYMBOL_GPL(usb_serial_generic_write); + +int usb_serial_generic_write_room(struct tty_struct *tty) +{ + struct usb_serial_port *port = tty->driver_data; + unsigned long flags; + int room; + + if (!port->bulk_out_size) + return 0; + + spin_lock_irqsave(&port->lock, flags); + room = kfifo_avail(&port->write_fifo); + spin_unlock_irqrestore(&port->lock, flags); + + dev_dbg(&port->dev, "%s - returns %d\n", __func__, room); + return room; +} + +int usb_serial_generic_chars_in_buffer(struct tty_struct *tty) +{ + struct usb_serial_port *port = tty->driver_data; + unsigned long flags; + int chars; + + if (!port->bulk_out_size) + return 0; + + spin_lock_irqsave(&port->lock, flags); + chars = kfifo_len(&port->write_fifo) + port->tx_bytes; + spin_unlock_irqrestore(&port->lock, flags); + + dev_dbg(&port->dev, "%s - returns %d\n", __func__, chars); + return chars; +} +EXPORT_SYMBOL_GPL(usb_serial_generic_chars_in_buffer); + +void usb_serial_generic_wait_until_sent(struct tty_struct *tty, long timeout) +{ + struct usb_serial_port *port = tty->driver_data; + unsigned int bps; + unsigned long period; + unsigned long expire; + + bps = tty_get_baud_rate(tty); + if (!bps) + bps = 9600; /* B0 */ + /* + * Use a poll-period of roughly the time it takes to send one + * character or at least one jiffy. + */ + period = max_t(unsigned long, (10 * HZ / bps), 1); + if (timeout) + period = min_t(unsigned long, period, timeout); + + dev_dbg(&port->dev, "%s - timeout = %u ms, period = %u ms\n", + __func__, jiffies_to_msecs(timeout), + jiffies_to_msecs(period)); + expire = jiffies + timeout; + while (!port->serial->type->tx_empty(port)) { + schedule_timeout_interruptible(period); + if (signal_pending(current)) + break; + if (timeout && time_after(jiffies, expire)) + break; + } +} +EXPORT_SYMBOL_GPL(usb_serial_generic_wait_until_sent); + +static int usb_serial_generic_submit_read_urb(struct usb_serial_port *port, + int index, gfp_t mem_flags) +{ + int res; + + if (!test_and_clear_bit(index, &port->read_urbs_free)) + return 0; + + dev_dbg(&port->dev, "%s - urb %d\n", __func__, index); + + res = usb_submit_urb(port->read_urbs[index], mem_flags); + if (res) { + if (res != -EPERM && res != -ENODEV) { + dev_err(&port->dev, + "%s - usb_submit_urb failed: %d\n", + __func__, res); + } + set_bit(index, &port->read_urbs_free); + return res; + } + + return 0; +} + +int usb_serial_generic_submit_read_urbs(struct usb_serial_port *port, + gfp_t mem_flags) +{ + int res; + int i; + + for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) { + res = usb_serial_generic_submit_read_urb(port, i, mem_flags); + if (res) + goto err; + } + + return 0; +err: + for (; i >= 0; --i) + usb_kill_urb(port->read_urbs[i]); + + return res; +} +EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urbs); + +void usb_serial_generic_process_read_urb(struct urb *urb) +{ + struct usb_serial_port *port = urb->context; + char *ch = (char *)urb->transfer_buffer; + int i; + + if (!urb->actual_length) + return; + /* + * The per character mucking around with sysrq path it too slow for + * stuff like 3G modems, so shortcircuit it in the 99.9999999% of + * cases where the USB serial is not a console anyway. + */ + if (!port->port.console || !port->sysrq) { + tty_insert_flip_string(&port->port, ch, urb->actual_length); + } else { + for (i = 0; i < urb->actual_length; i++, ch++) { + if (!usb_serial_handle_sysrq_char(port, *ch)) + tty_insert_flip_char(&port->port, *ch, TTY_NORMAL); + } + } + tty_flip_buffer_push(&port->port); +} +EXPORT_SYMBOL_GPL(usb_serial_generic_process_read_urb); + +void usb_serial_generic_read_bulk_callback(struct urb *urb) +{ + struct usb_serial_port *port = urb->context; + unsigned char *data = urb->transfer_buffer; + unsigned long flags; + int i; + + for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) { + if (urb == port->read_urbs[i]) + break; + } + set_bit(i, &port->read_urbs_free); + + dev_dbg(&port->dev, "%s - urb %d, len %d\n", __func__, i, + urb->actual_length); + switch (urb->status) { + case 0: + break; + case -ENOENT: + case -ECONNRESET: + case -ESHUTDOWN: + dev_dbg(&port->dev, "%s - urb stopped: %d\n", + __func__, urb->status); + return; + case -EPIPE: + dev_err(&port->dev, "%s - urb stopped: %d\n", + __func__, urb->status); + return; + default: + dev_dbg(&port->dev, "%s - nonzero urb status: %d\n", + __func__, urb->status); + goto resubmit; + } + + usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data); + port->serial->type->process_read_urb(urb); + +resubmit: + /* Throttle the device if requested by tty */ + spin_lock_irqsave(&port->lock, flags); + port->throttled = port->throttle_req; + if (!port->throttled) { + spin_unlock_irqrestore(&port->lock, flags); + usb_serial_generic_submit_read_urb(port, i, GFP_ATOMIC); + } else { + spin_unlock_irqrestore(&port->lock, flags); + } +} +EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback); + +void usb_serial_generic_write_bulk_callback(struct urb *urb) +{ + unsigned long flags; + struct usb_serial_port *port = urb->context; + int i; + + for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i) { + if (port->write_urbs[i] == urb) + break; + } + spin_lock_irqsave(&port->lock, flags); + port->tx_bytes -= urb->transfer_buffer_length; + set_bit(i, &port->write_urbs_free); + spin_unlock_irqrestore(&port->lock, flags); + + switch (urb->status) { + case 0: + break; + case -ENOENT: + case -ECONNRESET: + case -ESHUTDOWN: + dev_dbg(&port->dev, "%s - urb stopped: %d\n", + __func__, urb->status); + return; + case -EPIPE: + dev_err_console(port, "%s - urb stopped: %d\n", + __func__, urb->status); + return; + default: + dev_err_console(port, "%s - nonzero urb status: %d\n", + __func__, urb->status); + goto resubmit; + } + +resubmit: + usb_serial_generic_write_start(port, GFP_ATOMIC); + usb_serial_port_softint(port); +} +EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback); + +void usb_serial_generic_throttle(struct tty_struct *tty) +{ + struct usb_serial_port *port = tty->driver_data; + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + port->throttle_req = 1; + spin_unlock_irqrestore(&port->lock, flags); +} +EXPORT_SYMBOL_GPL(usb_serial_generic_throttle); + +void usb_serial_generic_unthrottle(struct tty_struct *tty) +{ + struct usb_serial_port *port = tty->driver_data; + int was_throttled; + + spin_lock_irq(&port->lock); + was_throttled = port->throttled; + port->throttled = port->throttle_req = 0; + spin_unlock_irq(&port->lock); + + if (was_throttled) + usb_serial_generic_submit_read_urbs(port, GFP_KERNEL); +} +EXPORT_SYMBOL_GPL(usb_serial_generic_unthrottle); + +static bool usb_serial_generic_msr_changed(struct tty_struct *tty, + unsigned long arg, struct async_icount *cprev) +{ + struct usb_serial_port *port = tty->driver_data; + struct async_icount cnow; + unsigned long flags; + bool ret; + + /* + * Use tty-port initialised flag to detect all hangups including the + * one generated at USB-device disconnect. + */ + if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags)) + return true; + + spin_lock_irqsave(&port->lock, flags); + cnow = port->icount; /* atomic copy*/ + spin_unlock_irqrestore(&port->lock, flags); + + ret = ((arg & TIOCM_RNG) && (cnow.rng != cprev->rng)) || + ((arg & TIOCM_DSR) && (cnow.dsr != cprev->dsr)) || + ((arg & TIOCM_CD) && (cnow.dcd != cprev->dcd)) || + ((arg & TIOCM_CTS) && (cnow.cts != cprev->cts)); + + *cprev = cnow; + + return ret; +} + +int usb_serial_generic_tiocmiwait(struct tty_struct *tty, unsigned long arg) +{ + struct usb_serial_port *port = tty->driver_data; + struct async_icount cnow; + unsigned long flags; + int ret; + + spin_lock_irqsave(&port->lock, flags); + cnow = port->icount; /* atomic copy */ + spin_unlock_irqrestore(&port->lock, flags); + + ret = wait_event_interruptible(port->port.delta_msr_wait, + usb_serial_generic_msr_changed(tty, arg, &cnow)); + if (!ret && !test_bit(ASYNCB_INITIALIZED, &port->port.flags)) + ret = -EIO; + + return ret; +} +EXPORT_SYMBOL_GPL(usb_serial_generic_tiocmiwait); + +int usb_serial_generic_get_icount(struct tty_struct *tty, + struct serial_icounter_struct *icount) +{ + struct usb_serial_port *port = tty->driver_data; + struct async_icount cnow; + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + cnow = port->icount; /* atomic copy */ + spin_unlock_irqrestore(&port->lock, flags); + + icount->cts = cnow.cts; + icount->dsr = cnow.dsr; + icount->rng = cnow.rng; + icount->dcd = cnow.dcd; + icount->tx = cnow.tx; + icount->rx = cnow.rx; + icount->frame = cnow.frame; + icount->parity = cnow.parity; + icount->overrun = cnow.overrun; + icount->brk = cnow.brk; + icount->buf_overrun = cnow.buf_overrun; + + return 0; +} +EXPORT_SYMBOL_GPL(usb_serial_generic_get_icount); + +#ifdef CONFIG_MAGIC_SYSRQ +int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch) +{ + if (port->sysrq && port->port.console) { + if (ch && time_before(jiffies, port->sysrq)) { + handle_sysrq(ch); + port->sysrq = 0; + return 1; + } + port->sysrq = 0; + } + return 0; +} +#else +int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch) +{ + return 0; +} +#endif +EXPORT_SYMBOL_GPL(usb_serial_handle_sysrq_char); + +int usb_serial_handle_break(struct usb_serial_port *port) +{ + if (!port->sysrq) { + port->sysrq = jiffies + HZ*5; + return 1; + } + port->sysrq = 0; + return 0; +} +EXPORT_SYMBOL_GPL(usb_serial_handle_break); + +/** + * usb_serial_handle_dcd_change - handle a change of carrier detect state + * @port: usb-serial port + * @tty: tty for the port + * @status: new carrier detect status, nonzero if active + */ +void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port, + struct tty_struct *tty, unsigned int status) +{ + struct tty_port *port = &usb_port->port; + + dev_dbg(&usb_port->dev, "%s - status %d\n", __func__, status); + + if (tty) { + struct tty_ldisc *ld = tty_ldisc_ref(tty); + + if (ld) { + if (ld->ops->dcd_change) + ld->ops->dcd_change(tty, status); + tty_ldisc_deref(ld); + } + } + + if (status) + wake_up_interruptible(&port->open_wait); + else if (tty && !C_CLOCAL(tty)) + tty_hangup(tty); +} +EXPORT_SYMBOL_GPL(usb_serial_handle_dcd_change); + +int usb_serial_generic_resume(struct usb_serial *serial) +{ + struct usb_serial_port *port; + int i, c = 0, r; + + for (i = 0; i < serial->num_ports; i++) { + port = serial->port[i]; + if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags)) + continue; + + if (port->bulk_in_size) { + r = usb_serial_generic_submit_read_urbs(port, + GFP_NOIO); + if (r < 0) + c++; + } + + if (port->bulk_out_size) { + r = usb_serial_generic_write_start(port, GFP_NOIO); + if (r < 0) + c++; + } + } + + return c ? -EIO : 0; +} +EXPORT_SYMBOL_GPL(usb_serial_generic_resume); |