/* * DMX USB driver * * Copyright (C) 2004,2006,2010 Erwin Rol (erwin@erwinrol.com) * * This driver is based on the usb-skeleton driver; * * Copyright (C) 2001-2003 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. * */ #include #include #include #include #include #include #include #include #include #include #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26) #include #else #include #endif #if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,36) ) #define init_MUTEX(LOCKNAME) sema_init(LOCKNAME,1); #endif #include "dmx_usb.h" #ifdef CONFIG_USB_DEBUG static int debug = 1; #else static int debug; #endif /* Use our own dbg macro */ #undef dbg #define dbg(format, arg...) do { if (debug) printk(KERN_DEBUG __FILE__ ": " format "\n" , ## arg); } while (0) #ifndef info #define info(format, arg...) do { printk(KERN_INFO __FILE__ ": " format "\n" , ## arg); } while (0) #endif #ifndef err #define err(format, arg...) do { printk(KERN_INFO __FILE__ ": (error) " format "\n" , ## arg); } while (0) #endif /* Version Information */ #define DRIVER_VERSION "v0.1.20111215" #define DRIVER_AUTHOR "Erwin Rol, erwin@erwinrol.com" #define DRIVER_DESC "DMX USB Driver" /* Module parameters */ #if ( LINUX_VERSION_CODE < KERNEL_VERSION(2,6,16) ) MODULE_PARM(debug, "i"); MODULE_PARM_DESC(debug, "Debug enabled or not"); #else module_param(debug, bool, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(debug, "Debug enabled or not"); #endif static struct usb_device_id dmx_usb_table [] = { { USB_DEVICE_VER(FTDI_VID, FTDI_8U232AM_PID, 0x400, 0xffff) }, { USB_DEVICE_VER(FTDI_VID, FTDI_8U232AM_ALT_PID, 0x400, 0xffff) }, { } /* Terminating entry */ }; MODULE_DEVICE_TABLE (usb, dmx_usb_table); /* Get a minor range for your devices from the usb maintainer */ #define DMX_USB_MINOR_BASE 192 /* Structure to hold all of our device specific stuff */ struct dmx_usb_device { struct usb_device * udev; /* save off the usb device pointer */ struct usb_interface * interface; /* the interface for this device */ unsigned char minor; /* the starting minor number for this device */ unsigned char num_ports; /* the number of ports this device has */ char num_interrupt_in; /* number of interrupt in endpoints we have */ char num_bulk_in; /* number of bulk in endpoints we have */ char num_bulk_out; /* number of bulk out endpoints we have */ unsigned char * bulk_in_buffer; /* the buffer to receive data */ size_t bulk_in_size; /* the size of the receive buffer */ __u8 bulk_in_endpointAddr; /* the address of the bulk in endpoint */ unsigned char * bulk_out_buffer; /* the buffer to send data */ size_t bulk_out_size; /* the size of the send buffer */ struct urb * write_urb; /* the urb used to send data */ __u8 bulk_out_endpointAddr; /* the address of the bulk out endpoint */ atomic_t write_busy; /* true iff write urb is busy */ struct completion write_finished; /* wait for the write to finish */ int open; /* if the port is open or not */ int present; /* if the device is not disconnected */ struct semaphore sem; /* locks this structure */ }; /* prevent races between open() and disconnect() */ #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,37) static DECLARE_MUTEX(disconnect_sem); #else static DEFINE_SEMAPHORE(disconnect_sem); #endif /* local function prototypes */ //static ssize_t dmx_usb_read (struct file *file, char *buffer, size_t count, loff_t *ppos); static ssize_t dmx_usb_write (struct file *file, const char *buffer, size_t count, loff_t *ppos); #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,37) ) static int dmx_usb_ioctl (struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg); #else static long dmx_usb_ioctl (struct file *file, unsigned int cmd, unsigned long arg); #endif static int dmx_usb_open (struct inode *inode, struct file *file); static int dmx_usb_release (struct inode *inode, struct file *file); static int dmx_usb_probe (struct usb_interface *interface, const struct usb_device_id *id); static void dmx_usb_disconnect (struct usb_interface *interface); static void dmx_usb_write_bulk_callback (struct urb *urb); static struct file_operations dmx_usb_fops = { /* * The owner field is part of the module-locking * mechanism. The idea is that the kernel knows * which module to increment the use-counter of * BEFORE it calls the device's open() function. * This also means that the kernel can decrement * the use-counter again before calling release() * or should the open() function fail. */ .owner = THIS_MODULE, /* .read = dmx_usb_read, */ .write = dmx_usb_write, #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,37) ) .ioctl = dmx_usb_ioctl, #else .unlocked_ioctl = dmx_usb_ioctl, #endif .open = dmx_usb_open, .release = dmx_usb_release, }; /* * usb class driver info in order to get a minor number from the usb core, * and to have the device registered with devfs and the driver core */ static struct usb_class_driver dmx_usb_class = { .name = "usb/dmx%d", .fops = &dmx_usb_fops, .minor_base = DMX_USB_MINOR_BASE, }; /* usb specific object needed to register this driver with the usb subsystem */ static struct usb_driver dmx_usb_driver = { #if ( LINUX_VERSION_CODE < KERNEL_VERSION(2,6,16) ) .owner = THIS_MODULE, #endif .name = "dmx_usb", .probe = dmx_usb_probe, .disconnect = dmx_usb_disconnect, .id_table = dmx_usb_table, }; #if ( LINUX_VERSION_CODE < KERNEL_VERSION(2,6,34) ) static inline void *usb_alloc_coherent(struct usb_device *dev, size_t size, gfp_t mem_flags, dma_addr_t *dma) { return usb_buffer_alloc(dev, size, mem_flags, dma); } static inline void usb_free_coherent(struct usb_device *dev, size_t size, void *addr, dma_addr_t dma) { return usb_buffer_free(dev, size, addr, dma); } #endif /** */ static inline void dmx_usb_debug_data (const char *function, int size, const unsigned char *data) { int i; if (!debug) return; printk (KERN_DEBUG __FILE__": %s - length = %d, data = ", function, size); for (i = 0; i < size; ++i) { printk ("%.2x ", data[i]); } printk ("\n"); } static __u32 dmx_usb_baud_to_divisor(int baud) { static const unsigned char divfrac[8] = { 0, 3, 2, 4, 1, 5, 6, 7 }; __u32 divisor; int divisor3 = 48000000 / 2 / baud; // divisor shifted 3 bits to the left divisor = divisor3 >> 3; divisor |= (__u32)divfrac[divisor3 & 0x7] << 14; /* Deal with special cases for highest baud rates. */ if (divisor == 1) divisor = 0; else // 1.0 if (divisor == 0x4001) divisor = 1; // 1.5 return divisor; } static int dmx_usb_set_speed(struct dmx_usb_device* dev) { char *buf; __u16 urb_value; __u16 urb_index; __u32 urb_index_value; int rv; buf = kmalloc(1, GFP_NOIO); if (!buf) return -ENOMEM; urb_index_value = dmx_usb_baud_to_divisor(250000); urb_value = (__u16)urb_index_value; urb_index = (__u16)(urb_index_value >> 16); rv = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0), FTDI_SIO_SET_BAUDRATE_REQUEST, FTDI_SIO_SET_BAUDRATE_REQUEST_TYPE, urb_value, urb_index, buf, 0, HZ*10); kfree(buf); return rv; } static int dmx_usb_setup(struct dmx_usb_device* dev) { __u16 urb_value; char buf[1]; urb_value = FTDI_SIO_SET_DATA_STOP_BITS_2 | FTDI_SIO_SET_DATA_PARITY_NONE; urb_value |= 8; // number of data bits if (usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0), FTDI_SIO_SET_DATA_REQUEST, FTDI_SIO_SET_DATA_REQUEST_TYPE, urb_value , 0, buf, 0, HZ*10) < 0) { err("%s FAILED to set databits/stopbits/parity", __FUNCTION__); } if (usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0), FTDI_SIO_SET_FLOW_CTRL_REQUEST, FTDI_SIO_SET_FLOW_CTRL_REQUEST_TYPE, 0, 0, buf, 0, HZ*10) < 0) { err("%s error from disable flowcontrol urb", __FUNCTION__); } dmx_usb_set_speed(dev); return 0; } static void dmx_usb_set_break(struct dmx_usb_device* dev, int break_state) { __u16 urb_value = FTDI_SIO_SET_DATA_STOP_BITS_2 | FTDI_SIO_SET_DATA_PARITY_NONE | 8; char buf[2]; if (break_state) { urb_value |= FTDI_SIO_SET_BREAK; } if (usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0), FTDI_SIO_SET_DATA_REQUEST, FTDI_SIO_SET_DATA_REQUEST_TYPE, urb_value , 0, buf, 2, HZ*10) < 0) { err("%s FAILED to enable/disable break state (state was %d)", __FUNCTION__,break_state); } dbg("%s break state is %d - urb is %d", __FUNCTION__,break_state, urb_value); } /** */ static inline void dmx_usb_delete (struct dmx_usb_device *dev) { kfree (dev->bulk_in_buffer); usb_free_coherent (dev->udev, dev->bulk_out_size, dev->bulk_out_buffer, dev->write_urb->transfer_dma); usb_free_urb (dev->write_urb); kfree (dev); } /** */ static int dmx_usb_open (struct inode *inode, struct file *file) { struct dmx_usb_device *dev = NULL; struct usb_interface *interface; int subminor; int retval = 0; dbg("%s", __FUNCTION__); subminor = iminor(inode); /* prevent disconnects */ down (&disconnect_sem); interface = usb_find_interface (&dmx_usb_driver, subminor); if (!interface) { err ("%s - error, can't find device for minor %d", __FUNCTION__, subminor); retval = -ENODEV; goto exit_no_device; } dev = usb_get_intfdata(interface); if (!dev) { retval = -ENODEV; goto exit_no_device; } /* lock this device */ down (&dev->sem); /* increment our usage count for the driver */ ++dev->open; /* save our object in the file's private structure */ file->private_data = dev; /* unlock this device */ up (&dev->sem); exit_no_device: up (&disconnect_sem); return retval; } /** */ static int dmx_usb_release (struct inode *inode, struct file *file) { struct dmx_usb_device *dev; int retval = 0; dev = (struct dmx_usb_device *)file->private_data; if (dev == NULL) { dbg ("%s - object is NULL", __FUNCTION__); return -ENODEV; } dbg("%s - minor %d", __FUNCTION__, dev->minor); /* lock our device */ down (&dev->sem); if (dev->open <= 0) { dbg ("%s - device not opened", __FUNCTION__); retval = -ENODEV; goto exit_not_opened; } /* wait for any bulk writes that might be going on to finish up */ if (atomic_read (&dev->write_busy)) wait_for_completion (&dev->write_finished); --dev->open; if (!dev->present && !dev->open) { /* the device was unplugged before the file was released */ up (&dev->sem); dmx_usb_delete (dev); return 0; } exit_not_opened: up (&dev->sem); return retval; } #if 0 Read is not yet supported /** */ static ssize_t dmx_usb_read (struct file *file, char *buffer, size_t count, loff_t *ppos) { struct dmx_usb_device *dev; int retval = 0; int bytes_read; dev = (struct dmx_usb_device *)file->private_data; dbg("%s - minor %d, count = %Zd", __FUNCTION__, dev->minor, count); /* lock this object */ down (&dev->sem); /* verify that the device wasn't unplugged */ if (!dev->present) { up (&dev->sem); return -ENODEV; } /* do a blocking bulk read to get data from the device */ retval = usb_bulk_msg (dev->udev, usb_rcvbulkpipe (dev->udev, dev->bulk_in_endpointAddr), dev->bulk_in_buffer, min (dev->bulk_in_size, count), &bytes_read, HZ*10); /* if the read was successful, copy the data to userspace */ if (!retval) { if (copy_to_user (buffer, dev->bulk_in_buffer+2, bytes_read-2)) retval = -EFAULT; else retval = bytes_read; } /* unlock the device */ up (&dev->sem); return retval; } #endif static __u16 dmx_usb_get_status(struct dmx_usb_device* dev) { int retval = 0; int count = 0; __u16 buf; retval = usb_bulk_msg (dev->udev, usb_rcvbulkpipe (dev->udev, dev->bulk_in_endpointAddr), &buf, 2, &count, HZ*10); if (retval) return 0; return buf; } /** * dmx_usb_write * * A device driver has to decide how to report I/O errors back to the * user. The safest course is to wait for the transfer to finish before * returning so that any errors will be reported reliably. dmx_usb_read() * works like this. But waiting for I/O is slow, so many drivers only * check for errors during I/O initiation and do not report problems * that occur during the actual transfer. That's what we will do here. * * A driver concerned with maximum I/O throughput would use double- * buffering: Two urbs would be devoted to write transfers, so that * one urb could always be active while the other was waiting for the * user to send more data. */ static ssize_t dmx_usb_write (struct file *file, const char *buffer, size_t count, loff_t *ppos) { struct dmx_usb_device *dev; ssize_t bytes_written = 0; int retval = 0; __u16 stat; dev = (struct dmx_usb_device *)file->private_data; dbg("%s - minor %d, count = %Zd", __FUNCTION__, dev->minor, count); /* lock this object */ down (&dev->sem); /* verify that the device wasn't unplugged */ if (!dev->present) { retval = -ENODEV; goto exit; } /* verify that we actually have some data to write */ if (count == 0) { dbg("%s - write request of 0 bytes", __FUNCTION__); goto exit; } /* wait for a previous write to finish up; we don't use a timeout * and so a nonresponsive device can delay us indefinitely. */ if (atomic_read (&dev->write_busy)) wait_for_completion (&dev->write_finished); /* we can only write as much as our buffer will hold */ bytes_written = min (dev->bulk_out_size, count); /* copy the data from userspace into our transfer buffer; * this is the only copy required. */ if (copy_from_user(dev->write_urb->transfer_buffer, buffer, bytes_written)) { retval = -EFAULT; goto exit; } dmx_usb_debug_data (__FUNCTION__, bytes_written, dev->write_urb->transfer_buffer); /* this urb was already set up, except for this write size */ dev->write_urb->transfer_buffer_length = bytes_written; /* Poll the device to see if the transmit buffer is empty */ do { stat = dmx_usb_get_status(dev); if (stat == 0) { retval = -EFAULT; goto exit; } } while ( (stat & ((FTDI_RS_TEMT) << 8) ) == 0 ) ; /* the transmit buffer is empty, now toggle the break */ dmx_usb_set_break(dev, 1); dmx_usb_set_break(dev, 0); /* send the data out the bulk port */ /* a character device write uses GFP_KERNEL, unless a spinlock is held */ init_completion (&dev->write_finished); atomic_set (&dev->write_busy, 1); retval = usb_submit_urb(dev->write_urb, GFP_KERNEL); if (retval) { atomic_set (&dev->write_busy, 0); err("%s - failed submitting write urb, error %d", __FUNCTION__, retval); } else { retval = bytes_written; } exit: /* unlock the device */ up (&dev->sem); return retval; } /** */ #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,37) ) static int dmx_usb_ioctl (struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) #else static long dmx_usb_ioctl (struct file *file, unsigned int cmd, unsigned long arg) #endif { struct dmx_usb_device *dev; dev = (struct dmx_usb_device *)file->private_data; /* lock this object */ down (&dev->sem); /* verify that the device wasn't unplugged */ if (!dev->present) { up (&dev->sem); return -ENODEV; } dbg("%s - minor %d, cmd 0x%.4x, arg %ld", __FUNCTION__, dev->minor, cmd, arg); /* fill in your device specific stuff here */ /* unlock the device */ up (&dev->sem); /* return that we did not understand this ioctl call */ return -ENOTTY; } /** */ static void dmx_usb_write_bulk_callback (struct urb *urb) { struct dmx_usb_device *dev = (struct dmx_usb_device *)urb->context; dbg("%s - minor %d", __FUNCTION__, dev->minor); /* sync/async unlink faults aren't errors */ if (urb->status && !(urb->status == -ENOENT || urb->status == -ECONNRESET)) { dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status); } /* notify anyone waiting that the write has finished */ atomic_set (&dev->write_busy, 0); complete (&dev->write_finished); } /** * * Called by the usb core when a new device is connected that it thinks * this driver might be interested in. */ static int dmx_usb_probe(struct usb_interface *interface, const struct usb_device_id *id) { struct usb_device *udev = interface_to_usbdev(interface); struct dmx_usb_device *dev = NULL; struct usb_host_interface *iface_desc; struct usb_endpoint_descriptor *endpoint; size_t buffer_size; int i; int retval = -ENOMEM; /* See if the device offered us matches what we can accept */ if ((le16_to_cpu(udev->descriptor.idVendor) != FTDI_VID) || (le16_to_cpu(udev->descriptor.idProduct) != FTDI_8U232AM_PID)) { return -ENODEV; } /* allocate memory for our device state and initialize it */ dev = kmalloc (sizeof(struct dmx_usb_device), GFP_KERNEL); if (dev == NULL) { err ("Out of memory"); return -ENOMEM; } memset (dev, 0x00, sizeof (*dev)); init_MUTEX (&dev->sem); dev->udev = udev; dev->interface = interface; /* set up the endpoint information */ /* check out the endpoints */ /* use only the first bulk-in and bulk-out endpoints */ iface_desc = &interface->altsetting[0]; for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) { endpoint = &iface_desc->endpoint[i].desc; if (!dev->bulk_in_endpointAddr && (endpoint->bEndpointAddress & USB_DIR_IN) && ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_BULK)) { /* we found a bulk in endpoint */ buffer_size = endpoint->wMaxPacketSize; dev->bulk_in_size = buffer_size; dev->bulk_in_endpointAddr = endpoint->bEndpointAddress; dev->bulk_in_buffer = kmalloc (buffer_size, GFP_KERNEL); if (!dev->bulk_in_buffer) { err("Couldn't allocate bulk_in_buffer"); goto error; } } if (!dev->bulk_out_endpointAddr && !(endpoint->bEndpointAddress & USB_DIR_IN) && ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_BULK)) { /* we found a bulk out endpoint */ /* a probe() may sleep and has no restrictions on memory allocations */ dev->write_urb = usb_alloc_urb(0, GFP_KERNEL); if (!dev->write_urb) { err("No free urbs available"); goto error; } dev->bulk_out_endpointAddr = endpoint->bEndpointAddress; /* on some platforms using this kind of buffer alloc * call eliminates a dma "bounce buffer". * * NOTE: you'd normally want i/o buffers that hold * more than one packet, so that i/o delays between * packets don't hurt throughput. */ buffer_size = endpoint->wMaxPacketSize; dev->bulk_out_size = 513; dev->write_urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP; dev->bulk_out_buffer = usb_alloc_coherent (udev, buffer_size, GFP_KERNEL, &dev->write_urb->transfer_dma); if (!dev->bulk_out_buffer) { err("Couldn't allocate bulk_out_buffer"); goto error; } usb_fill_bulk_urb(dev->write_urb, udev, usb_sndbulkpipe(udev, endpoint->bEndpointAddress), dev->bulk_out_buffer, buffer_size, dmx_usb_write_bulk_callback, dev); } } if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) { err("Couldn't find both bulk-in and bulk-out endpoints"); goto error; } dmx_usb_setup(dev); /* allow device read, write and ioctl */ dev->present = 1; /* we can register the device now, as it is ready */ usb_set_intfdata (interface, dev); retval = usb_register_dev (interface, &dmx_usb_class); if (retval) { /* something prevented us from registering this driver */ err ("Not able to get a minor for this device."); usb_set_intfdata (interface, NULL); goto error; } dev->minor = interface->minor; /* let the user know what node this device is now attached to */ info ("DMX USB device now attached to dmx%d", dev->minor); return 0; error: dmx_usb_delete (dev); return retval; } /** * * Called by the usb core when the device is removed from the system. * * This routine guarantees that the driver will not submit any more urbs * by clearing dev->udev. It is also supposed to terminate any currently * active urbs. Unfortunately, usb_bulk_msg(), used in dmx_usb_read(), does * not provide any way to do this. But at least we can cancel an active * write. */ static void dmx_usb_disconnect(struct usb_interface *interface) { struct dmx_usb_device *dev; int minor; /* prevent races with open() */ down (&disconnect_sem); dev = usb_get_intfdata (interface); usb_set_intfdata (interface, NULL); down (&dev->sem); minor = dev->minor; /* give back our minor */ usb_deregister_dev (interface, &dmx_usb_class); /* terminate an ongoing write */ if (atomic_read (&dev->write_busy)) { usb_unlink_urb (dev->write_urb); wait_for_completion (&dev->write_finished); } /* prevent device read, write and ioctl */ dev->present = 0; up (&dev->sem); /* if the device is opened, dmx_usb_release will clean this up */ if (!dev->open) dmx_usb_delete (dev); up (&disconnect_sem); info("DMX USB #%d now disconnected", minor); } /** * dmx_usb_init */ static int __init dmx_usb_init(void) { int result; /* register this driver with the USB subsystem */ result = usb_register(&dmx_usb_driver); if (result) { err("usb_register failed. Error number %d", result); return result; } info(DRIVER_DESC " " DRIVER_VERSION); return 0; } /** * dmx_usb_exit */ static void __exit dmx_usb_exit(void) { /* deregister this driver with the USB subsystem */ usb_deregister(&dmx_usb_driver); } module_init (dmx_usb_init); module_exit (dmx_usb_exit); MODULE_AUTHOR(DRIVER_AUTHOR); MODULE_DESCRIPTION(DRIVER_DESC); MODULE_LICENSE("GPL");