diff options
| -rw-r--r-- | drivers/usb/class/usbtmc.c | 336 | ||||
| -rw-r--r-- | include/uapi/linux/usb/tmc.h | 2 |
2 files changed, 337 insertions, 1 deletions
diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c index eec382ab1a44..45ccdd087d6f 100644 --- a/drivers/usb/class/usbtmc.c +++ b/drivers/usb/class/usbtmc.c @@ -85,6 +85,9 @@ struct usbtmc_device_data { u8 bTag_last_write; /* needed for abort */ u8 bTag_last_read; /* needed for abort */ + /* packet size of IN bulk */ + u16 wMaxPacketSize; + /* data for interrupt in endpoint handling */ u8 bNotify1; u8 bNotify2; @@ -140,6 +143,13 @@ struct usbtmc_file_data { struct semaphore limit_write_sem; u32 out_transfer_size; int out_status; + + /* data for generic_read */ + u32 in_transfer_size; + int in_status; + int in_urbs_used; + struct usb_anchor in_anchor; + wait_queue_head_t wait_bulk_in; }; /* Forward declarations */ @@ -173,6 +183,8 @@ static int usbtmc_open(struct inode *inode, struct file *filp) spin_lock_init(&file_data->err_lock); sema_init(&file_data->limit_write_sem, MAX_URBS_IN_FLIGHT); init_usb_anchor(&file_data->submitted); + init_usb_anchor(&file_data->in_anchor); + init_waitqueue_head(&file_data->wait_bulk_in); data = usb_get_intfdata(intf); /* Protect reference to data from file structure until release */ @@ -219,6 +231,9 @@ static int usbtmc_flush(struct file *file, fl_owner_t id) usbtmc_draw_down(file_data); spin_lock_irq(&file_data->err_lock); + file_data->in_status = 0; + file_data->in_transfer_size = 0; + file_data->in_urbs_used = 0; file_data->out_status = 0; file_data->out_transfer_size = 0; spin_unlock_irq(&file_data->err_lock); @@ -682,6 +697,307 @@ static struct urb *usbtmc_create_urb(void) return urb; } +static void usbtmc_read_bulk_cb(struct urb *urb) +{ + struct usbtmc_file_data *file_data = urb->context; + int status = urb->status; + unsigned long flags; + + /* sync/async unlink faults aren't errors */ + if (status) { + if (!(/* status == -ENOENT || */ + status == -ECONNRESET || + status == -EREMOTEIO || /* Short packet */ + status == -ESHUTDOWN)) + dev_err(&file_data->data->intf->dev, + "%s - nonzero read bulk status received: %d\n", + __func__, status); + + spin_lock_irqsave(&file_data->err_lock, flags); + if (!file_data->in_status) + file_data->in_status = status; + spin_unlock_irqrestore(&file_data->err_lock, flags); + } + + spin_lock_irqsave(&file_data->err_lock, flags); + file_data->in_transfer_size += urb->actual_length; + dev_dbg(&file_data->data->intf->dev, + "%s - total size: %u current: %d status: %d\n", + __func__, file_data->in_transfer_size, + urb->actual_length, status); + spin_unlock_irqrestore(&file_data->err_lock, flags); + usb_anchor_urb(urb, &file_data->in_anchor); + + wake_up_interruptible(&file_data->wait_bulk_in); + wake_up_interruptible(&file_data->data->waitq); +} + +static inline bool usbtmc_do_transfer(struct usbtmc_file_data *file_data) +{ + bool data_or_error; + + spin_lock_irq(&file_data->err_lock); + data_or_error = !usb_anchor_empty(&file_data->in_anchor) + || file_data->in_status; + spin_unlock_irq(&file_data->err_lock); + dev_dbg(&file_data->data->intf->dev, "%s: returns %d\n", __func__, + data_or_error); + return data_or_error; +} + +static ssize_t usbtmc_generic_read(struct usbtmc_file_data *file_data, + void __user *user_buffer, + u32 transfer_size, + u32 *transferred, + u32 flags) +{ + struct usbtmc_device_data *data = file_data->data; + struct device *dev = &data->intf->dev; + u32 done = 0; + u32 remaining; + const u32 bufsize = USBTMC_BUFSIZE; + int retval = 0; + u32 max_transfer_size; + unsigned long expire; + int bufcount = 1; + int again = 0; + + /* mutex already locked */ + + *transferred = done; + + max_transfer_size = transfer_size; + + if (flags & USBTMC_FLAG_IGNORE_TRAILER) { + /* The device may send extra alignment bytes (up to + * wMaxPacketSize – 1) to avoid sending a zero-length + * packet + */ + remaining = transfer_size; + if ((max_transfer_size % data->wMaxPacketSize) == 0) + max_transfer_size += (data->wMaxPacketSize - 1); + } else { + /* round down to bufsize to avoid truncated data left */ + if (max_transfer_size > bufsize) { + max_transfer_size = + roundup(max_transfer_size + 1 - bufsize, + bufsize); + } + remaining = max_transfer_size; + } + + spin_lock_irq(&file_data->err_lock); + + if (file_data->in_status) { + /* return the very first error */ + retval = file_data->in_status; + spin_unlock_irq(&file_data->err_lock); + goto error; + } + + if (flags & USBTMC_FLAG_ASYNC) { + if (usb_anchor_empty(&file_data->in_anchor)) + again = 1; + + if (file_data->in_urbs_used == 0) { + file_data->in_transfer_size = 0; + file_data->in_status = 0; + } + } else { + file_data->in_transfer_size = 0; + file_data->in_status = 0; + } + + if (max_transfer_size == 0) { + bufcount = 0; + } else { + bufcount = roundup(max_transfer_size, bufsize) / bufsize; + if (bufcount > file_data->in_urbs_used) + bufcount -= file_data->in_urbs_used; + else + bufcount = 0; + + if (bufcount + file_data->in_urbs_used > MAX_URBS_IN_FLIGHT) { + bufcount = MAX_URBS_IN_FLIGHT - + file_data->in_urbs_used; + } + } + spin_unlock_irq(&file_data->err_lock); + + dev_dbg(dev, "%s: requested=%u flags=0x%X size=%u bufs=%d used=%d\n", + __func__, transfer_size, flags, + max_transfer_size, bufcount, file_data->in_urbs_used); + + while (bufcount > 0) { + u8 *dmabuf = NULL; + struct urb *urb = usbtmc_create_urb(); + + if (!urb) { + retval = -ENOMEM; + goto error; + } + + dmabuf = urb->transfer_buffer; + + usb_fill_bulk_urb(urb, data->usb_dev, + usb_rcvbulkpipe(data->usb_dev, data->bulk_in), + dmabuf, bufsize, + usbtmc_read_bulk_cb, file_data); + + usb_anchor_urb(urb, &file_data->submitted); + retval = usb_submit_urb(urb, GFP_KERNEL); + /* urb is anchored. We can release our reference. */ + usb_free_urb(urb); + if (unlikely(retval)) { + usb_unanchor_urb(urb); + goto error; + } + file_data->in_urbs_used++; + bufcount--; + } + + if (again) { + dev_dbg(dev, "%s: ret=again\n", __func__); + return -EAGAIN; + } + + if (user_buffer == NULL) + return -EINVAL; + + expire = msecs_to_jiffies(file_data->timeout); + + while (max_transfer_size > 0) { + u32 this_part; + struct urb *urb = NULL; + + if (!(flags & USBTMC_FLAG_ASYNC)) { + dev_dbg(dev, "%s: before wait time %lu\n", + __func__, expire); + retval = wait_event_interruptible_timeout( + file_data->wait_bulk_in, + usbtmc_do_transfer(file_data), + expire); + + dev_dbg(dev, "%s: wait returned %d\n", + __func__, retval); + + if (retval <= 0) { + if (retval == 0) + retval = -ETIMEDOUT; + goto error; + } + } + + urb = usb_get_from_anchor(&file_data->in_anchor); + if (!urb) { + if (!(flags & USBTMC_FLAG_ASYNC)) { + /* synchronous case: must not happen */ + retval = -EFAULT; + goto error; + } + + /* asynchronous case: ready, do not block or wait */ + *transferred = done; + dev_dbg(dev, "%s: (async) done=%u ret=0\n", + __func__, done); + return 0; + } + + file_data->in_urbs_used--; + + if (max_transfer_size > urb->actual_length) + max_transfer_size -= urb->actual_length; + else + max_transfer_size = 0; + + if (remaining > urb->actual_length) + this_part = urb->actual_length; + else + this_part = remaining; + + print_hex_dump_debug("usbtmc ", DUMP_PREFIX_NONE, 16, 1, + urb->transfer_buffer, urb->actual_length, true); + + if (copy_to_user(user_buffer + done, + urb->transfer_buffer, this_part)) { + usb_free_urb(urb); + retval = -EFAULT; + goto error; + } + + remaining -= this_part; + done += this_part; + + spin_lock_irq(&file_data->err_lock); + if (urb->status) { + /* return the very first error */ + retval = file_data->in_status; + spin_unlock_irq(&file_data->err_lock); + usb_free_urb(urb); + goto error; + } + spin_unlock_irq(&file_data->err_lock); + + if (urb->actual_length < bufsize) { + /* short packet or ZLP received => ready */ + usb_free_urb(urb); + retval = 1; + break; + } + + if (!(flags & USBTMC_FLAG_ASYNC) && + max_transfer_size > (bufsize * file_data->in_urbs_used)) { + /* resubmit, since other buffers still not enough */ + usb_anchor_urb(urb, &file_data->submitted); + retval = usb_submit_urb(urb, GFP_KERNEL); + if (unlikely(retval)) { + usb_unanchor_urb(urb); + usb_free_urb(urb); + goto error; + } + file_data->in_urbs_used++; + } + usb_free_urb(urb); + retval = 0; + } + +error: + *transferred = done; + + dev_dbg(dev, "%s: before kill\n", __func__); + /* Attention: killing urbs can take long time (2 ms) */ + usb_kill_anchored_urbs(&file_data->submitted); + dev_dbg(dev, "%s: after kill\n", __func__); + usb_scuttle_anchored_urbs(&file_data->in_anchor); + file_data->in_urbs_used = 0; + file_data->in_status = 0; /* no spinlock needed here */ + dev_dbg(dev, "%s: done=%u ret=%d\n", __func__, done, retval); + + return retval; +} + +static ssize_t usbtmc_ioctl_generic_read(struct usbtmc_file_data *file_data, + void __user *arg) +{ + struct usbtmc_message msg; + ssize_t retval = 0; + + /* mutex already locked */ + + if (copy_from_user(&msg, arg, sizeof(struct usbtmc_message))) + return -EFAULT; + + retval = usbtmc_generic_read(file_data, msg.message, + msg.transfer_size, &msg.transferred, + msg.flags); + + if (put_user(msg.transferred, + &((struct usbtmc_message __user *)arg)->transferred)) + return -EFAULT; + + return retval; +} + static void usbtmc_write_bulk_cb(struct urb *urb) { struct usbtmc_file_data *file_data = urb->context; @@ -1383,6 +1699,7 @@ static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data) static int usbtmc_ioctl_cancel_io(struct usbtmc_file_data *file_data) { spin_lock_irq(&file_data->err_lock); + file_data->in_status = -ECANCELED; file_data->out_status = -ECANCELED; spin_unlock_irq(&file_data->err_lock); usb_kill_anchored_urbs(&file_data->submitted); @@ -1768,6 +2085,11 @@ static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg) (void __user *)arg); break; + case USBTMC_IOCTL_READ: + retval = usbtmc_ioctl_generic_read(file_data, + (void __user *)arg); + break; + case USBTMC_IOCTL_WRITE_RESULT: retval = usbtmc_ioctl_write_result(file_data, (void __user *)arg); @@ -1833,15 +2155,24 @@ static __poll_t usbtmc_poll(struct file *file, poll_table *wait) poll_wait(file, &data->waitq, wait); + /* Note that EPOLLPRI is now assigned to SRQ, and + * EPOLLIN|EPOLLRDNORM to normal read data. + */ mask = 0; if (atomic_read(&file_data->srq_asserted)) mask |= EPOLLPRI; + /* Note that the anchor submitted includes all urbs for BULK IN + * and OUT. So EPOLLOUT is signaled when BULK OUT is empty and + * all BULK IN urbs are completed and moved to in_anchor. + */ if (usb_anchor_empty(&file_data->submitted)) mask |= (EPOLLOUT | EPOLLWRNORM); + if (!usb_anchor_empty(&file_data->in_anchor)) + mask |= (EPOLLIN | EPOLLRDNORM); spin_lock_irq(&file_data->err_lock); - if (file_data->out_status) + if (file_data->in_status || file_data->out_status) mask |= EPOLLERR; spin_unlock_irq(&file_data->err_lock); @@ -2003,6 +2334,7 @@ static int usbtmc_probe(struct usb_interface *intf, } data->bulk_in = bulk_in->bEndpointAddress; + data->wMaxPacketSize = usb_endpoint_maxp(bulk_in); dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n", data->bulk_in); data->bulk_out = bulk_out->bEndpointAddress; @@ -2099,6 +2431,7 @@ static void usbtmc_disconnect(struct usb_interface *intf) struct usbtmc_file_data, file_elem); usb_kill_anchored_urbs(&file_data->submitted); + usb_scuttle_anchored_urbs(&file_data->in_anchor); } mutex_unlock(&data->io_mutex); usbtmc_free_int(data); @@ -2112,6 +2445,7 @@ static void usbtmc_draw_down(struct usbtmc_file_data *file_data) time = usb_wait_anchor_empty_timeout(&file_data->submitted, 1000); if (!time) usb_kill_anchored_urbs(&file_data->submitted); + usb_scuttle_anchored_urbs(&file_data->in_anchor); } static int usbtmc_suspend(struct usb_interface *intf, pm_message_t message) diff --git a/include/uapi/linux/usb/tmc.h b/include/uapi/linux/usb/tmc.h index 0166ba5452d5..f0fd0d4334ec 100644 --- a/include/uapi/linux/usb/tmc.h +++ b/include/uapi/linux/usb/tmc.h @@ -64,6 +64,7 @@ struct usbtmc_termchar { */ #define USBTMC_FLAG_ASYNC 0x0001 #define USBTMC_FLAG_APPEND 0x0002 +#define USBTMC_FLAG_IGNORE_TRAILER 0x0004 struct usbtmc_message { __u32 transfer_size; /* size of bytes to transfer */ @@ -86,6 +87,7 @@ struct usbtmc_message { #define USBTMC_IOCTL_EOM_ENABLE _IOW(USBTMC_IOC_NR, 11, __u8) #define USBTMC_IOCTL_CONFIG_TERMCHAR _IOW(USBTMC_IOC_NR, 12, struct usbtmc_termchar) #define USBTMC_IOCTL_WRITE _IOWR(USBTMC_IOC_NR, 13, struct usbtmc_message) +#define USBTMC_IOCTL_READ _IOWR(USBTMC_IOC_NR, 14, struct usbtmc_message) #define USBTMC_IOCTL_WRITE_RESULT _IOWR(USBTMC_IOC_NR, 15, __u32) #define USBTMC488_IOCTL_GET_CAPS _IOR(USBTMC_IOC_NR, 17, unsigned char) |