/**************************************************************************** * drivers/usbhost/usbhost_cdcacm.c * * Copyright (C) 2015-2017 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_USBHOST_CDCACM /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /* Configuration ************************************************************/ #ifndef CONFIG_USBHOST # warning USB host support not enabled (CONFIG_USBHOST) #endif #ifdef CONFIG_USBHOST_BULK_DISABLE # warning USB bulk endpoint support is disabled (CONFIG_USBHOST_BULK_DISABLE) #endif #ifdef CONFIG_USBHOST_INT_DISABLE # warning USB interrupt endpoint support is disabled (CONFIG_USBHOST_INT_DISABLE) #endif #if !defined(CONFIG_SCHED_WORKQUEUE) # warning Worker thread support is required (CONFIG_SCHED_WORKQUEUE) #else # ifndef CONFIG_SCHED_HPWORK # warning High priority work thread support is required (CONFIG_SCHED_HPWORK) # endif # ifndef CONFIG_SCHED_LPWORK # warning Low priority work thread support is required (CONFIG_SCHED_LPWORK) # endif # if CONFIG_SCHED_LPNTHREADS < 2 # warning Multiple low priority work threads recommended for performance (CONFIG_SCHED_LPNTHREADS > 1) # endif #endif #ifndef CONFIG_USBHOST_ASYNCH # warning Asynchronous transfer support is required (CONFIG_USBHOST_ASYNCH) #endif #ifndef CONFIG_SERIAL_REMOVABLE # warning Removable serial device support is required (CONFIG_SERIAL_REMOVABLE) #endif #ifdef CONFIG_USBHOST_CDCACM_NTDELAY # define USBHOST_CDCACM_NTDELAY MSEC2TICK(CONFIG_USBHOST_CDCACM_NTDELAY) #else # define USBHOST_CDCACM_NTDELAY MSEC2TICK(200) #endif #ifdef CONFIG_USBHOST_CDCACM_RXDELAY # define USBHOST_CDCACM_RXDELAY MSEC2TICK(CONFIG_USBHOST_CDCACM_RXDELAY) #else # define USBHOST_CDCACM_RXDELAY MSEC2TICK(200) #endif #ifdef CONFIG_USBHOST_CDCACM_TXDELAY # define USBHOST_CDCACM_TXDELAY MSEC2TICK(CONFIG_USBHOST_CDCACM_TXDELAY) #else # define USBHOST_CDCACM_TXDELAY MSEC2TICK(200) #endif /* Supported protocol */ #define HAVE_CLASS_REQUESTS 1 #define HAVE_INTIN_ENDPOINT 1 #define HAVE_CTRL_INTERFACE 1 #if defined(CONFIG_USBHOST_CDCACM_REDUCED) # undef CONFIG_USBHOST_CDCACM_BULKONLY # undef CONFIG_USBHOST_CDCACM_COMPLIANT # undef HAVE_INTIN_ENDPOINT #elif defined(CONFIG_USBHOST_CDCACM_BULKONLY) # undef CONFIG_USBHOST_CDCACM_COMPLIANT # undef HAVE_CLASS_REQUESTS # undef HAVE_INTIN_ENDPOINT # undef HAVE_CTRL_INTERFACE #endif /* If the create() method is called by the USB host device driver from an * interrupt handler, then it will be unable to call kmm_malloc() in order to * allocate a new class instance. If the create() method is called from the * interrupt level, then class instances must be pre-allocated. */ #ifndef CONFIG_USBHOST_CDCACM_NPREALLOC # define CONFIG_USBHOST_CDCACM_NPREALLOC 0 #endif #if CONFIG_USBHOST_CDCACM_NPREALLOC > 32 # error Currently limited to 32 devices /dev/ttyACM[n] #endif #ifndef CONFIG_USBHOST_CDCACM_RXBUFSIZE # define CONFIG_USBHOST_CDCACM_RXBUFSIZE 128 #endif #ifndef CONFIG_USBHOST_CDCACM_TXBUFSIZE # define CONFIG_USBHOST_CDCACM_TXBUFSIZE 128 #endif /* Initial line coding */ #ifndef CONFIG_USBHOST_CDCACM_BAUD # define CONFIG_USBHOST_CDCACM_BAUD 115200 #endif #ifndef CONFIG_USBHOST_CDCACM_PARITY # define CONFIG_USBHOST_CDCACM_PARITY 0 #endif #ifndef CONFIG_USBHOST_CDCACM_BITS # define CONFIG_USBHOST_CDCACM_BITS 8 #endif #ifndef CONFIG_USBHOST_CDCACM_2STOP # define CONFIG_USBHOST_CDCACM_2STOP 0 #endif /* Driver support ***********************************************************/ /* This format is used to construct the /dev/sd[n] device driver path. It * defined here so that it will be used consistently in all places. */ #define DEV_FORMAT "/dev/ttyACM%d" #define DEV_NAMELEN 16 #define MAX_NOTIFICATION 32 /* Used in usbhost_connect() */ #define USBHOST_DATAIF_FOUND 0x01 /* Data interface found */ #define USBHOST_BULKIN_FOUND 0x02 /* Bulk IN interface found */ #define USBHOST_BULKOUT_FOUND 0x04 /* Bulk OUT interface found */ #if defined(CONFIG_USBHOST_CDCACM_BULKONLY) # define USBHOST_MINFOUND 0x07 /* Minimum things needed */ # define USBHOST_ALLFOUND 0x07 /* All configuration things */ #elif defined(CONFIG_USBHOST_CDCACM_REDUCED) # define USBHOST_CTRLIF_FOUND 0x08 /* Control interface found */ # define USBHOST_MINFOUND 0x07 /* Minimum things needed */ # define USBHOST_HAVE_CTRLIF 0x08 /* Needed for control interface */ # define USBHOST_ALLFOUND 0x0f /* All configuration things */ #else # define USBHOST_CTRLIF_FOUND 0x08 /* Control interface found */ # define USBHOST_INTIN_FOUND 0x10 /* Interrupt IN interface found */ # define USBHOST_MINFOUND 0x07 /* Minimum things needed */ # define USBHOST_HAVE_CTRLIF 0x18 /* Needed for control interface */ # define USBHOST_ALLFOUND 0x1f /* All configuration things */ #endif #define USBHOST_MAX_CREFS INT16_MAX /* Max cref count before signed overflow */ /**************************************************************************** * Private Types ****************************************************************************/ /* This structure contains the internal, private state of the USB host * CDC/ACM class. */ struct usbhost_cdcacm_s { /* This is the externally visible portion of the state. The usbclass must * the first element of the structure. It is then cast compatible with * struct usbhost_cdcacm_s. */ struct usbhost_class_s usbclass; /* This is the standard of the lower-half serial interface. It is not * the first element of the structure, but includes a pointer back to the * the beginning of this structure. */ struct uart_dev_s uartdev; /* The remainder of the fields are provide to the CDC/ACM class */ volatile bool disconnected; /* TRUE: Device has been disconnected */ bool stop2; /* True: 2 stop bits (for line coding) */ bool dsr; /* State of transmission carrier */ bool dcd; /* State of receiver carrier detection */ bool txena; /* True: TX "interrupts" enabled */ bool rxena; /* True: RX "interrupts" enabled */ #ifdef CONFIG_SERIAL_IFLOWCONTROL bool iflow; /* True: Input flow control (RTS) enabled */ bool rts; /* True: Input flow control is in effect */ #endif #ifdef CONFIG_SERIAL_OFLOWCONTROL bool oflow; /* True: Output flow control (CTS) enabled */ #endif uint8_t minor; /* Minor number identifying the /dev/ttyACM[n] device */ uint8_t dataif; /* Data interface number */ #ifdef HAVE_CTRL_INTERFACE uint8_t ctrlif; /* Control interface number */ #endif uint8_t nbits; /* Number of bits (for line encoding) */ uint8_t parity; /* Parity (for line encoding) */ uint16_t pktsize; /* Allocated size of transfer buffers */ uint16_t nrxbytes; /* Number of bytes in the RX packet buffer */ uint16_t rxndx; /* Index to the next byte in the RX packet buffer */ int16_t crefs; /* Reference count on the driver instance */ int16_t nbytes; /* The number of bytes actually transferred */ sem_t exclsem; /* Used to maintain mutual exclusive access */ struct work_s ntwork; /* For asynchronous notification work */ struct work_s rxwork; /* For RX packet work */ struct work_s txwork; /* For TX packet work */ FAR uint8_t *ctrlreq; /* Allocated ctrl request structure */ FAR uint8_t *linecode; /* The allocated buffer for line encoding */ FAR uint8_t *notification; /* The allocated buffer for async notifications */ FAR uint8_t *inbuf; /* Allocated RX buffer for the Bulk IN endpoint */ FAR uint8_t *outbuf; /* Allocated TX buffer for the Bulk OUT endpoint */ uint32_t baud; /* Current baud for line coding */ usbhost_ep_t bulkin; /* Bulk IN endpoint */ usbhost_ep_t bulkout; /* Bulk OUT endpoint */ #ifdef HAVE_INTIN_ENDPOINT usbhost_ep_t intin; /* Interrupt IN endpoint (optional) */ #endif /* This is the serial data buffer */ char rxbuffer[CONFIG_USBHOST_CDCACM_RXBUFSIZE]; char txbuffer[CONFIG_USBHOST_CDCACM_TXBUFSIZE]; }; /* This is how struct usbhost_cdcacm_s looks to the free list logic */ struct usbhost_freestate_s { FAR struct usbhost_freestate_s *flink; }; /**************************************************************************** * Private Function Prototypes ****************************************************************************/ /* Semaphores */ static void usbhost_takesem(sem_t *sem); #define usbhost_givesem(s) nxsem_post(s); /* Memory allocation services */ static FAR struct usbhost_cdcacm_s *usbhost_allocclass(void); static void usbhost_freeclass(FAR struct usbhost_cdcacm_s *usbclass); /* Device name management */ static int usbhost_devno_alloc(FAR struct usbhost_cdcacm_s *priv); static void usbhost_devno_free(FAR struct usbhost_cdcacm_s *priv); static inline void usbhost_mkdevname(FAR struct usbhost_cdcacm_s *priv, FAR char *devname); /* CDC/ACM request helpers */ #ifdef HAVE_CTRL_INTERFACE static int usbhost_linecoding_send(FAR struct usbhost_cdcacm_s *priv); #ifdef HAVE_INTIN_ENDPOINT static void usbhost_notification_work(FAR void *arg); static void usbhost_notification_callback(FAR void *arg, ssize_t nbytes); #endif #endif /* UART buffer data transfer */ static void usbhost_txdata_work(FAR void *arg); static void usbhost_rxdata_work(FAR void *arg); /* Worker thread actions */ static void usbhost_destroy(FAR void *arg); /* Helpers for usbhost_connect() */ static int usbhost_cfgdesc(FAR struct usbhost_cdcacm_s *priv, FAR const uint8_t *configdesc, int desclen); /* (Little Endian) Data helpers */ static inline uint16_t usbhost_getle16(const uint8_t *val); static inline uint16_t usbhost_getbe16(const uint8_t *val); static inline void usbhost_putle16(uint8_t *dest, uint16_t val); #ifdef HAVE_CTRL_INTERFACE static void usbhost_putle32(uint8_t *dest, uint32_t val); #endif /* Transfer descriptor memory management */ static int usbhost_alloc_buffers(FAR struct usbhost_cdcacm_s *priv); static void usbhost_free_buffers(FAR struct usbhost_cdcacm_s *priv); /* struct usbhost_registry_s methods */ static struct usbhost_class_s *usbhost_create( FAR struct usbhost_hubport_s *hport, FAR const struct usbhost_id_s *id); /* struct usbhost_class_s methods */ static int usbhost_connect(FAR struct usbhost_class_s *usbclass, FAR const uint8_t *configdesc, int desclen); static int usbhost_disconnected(FAR struct usbhost_class_s *usbclass); /* Serial driver lower-half interfaces */ static int usbhost_setup(FAR struct uart_dev_s *uartdev); static void usbhost_shutdown(FAR struct uart_dev_s *uartdev); static int usbhost_attach(FAR struct uart_dev_s *uartdev); static void usbhost_detach(FAR struct uart_dev_s *uartdev); static int usbhost_ioctl(FAR struct file *filep, int cmd, unsigned long arg); static void usbhost_rxint(FAR struct uart_dev_s *uartdev, bool enable); static bool usbhost_rxavailable(FAR struct uart_dev_s *uartdev); #ifdef CONFIG_SERIAL_IFLOWCONTROL static bool usbhost_rxflowcontrol(FAR struct uart_dev_s *uartdev, unsigned int nbuffered, bool upper); #endif static void usbhost_txint(FAR struct uart_dev_s *uartdev, bool enable); static bool usbhost_txready(FAR struct uart_dev_s *uartdev); static bool usbhost_txempty(FAR struct uart_dev_s *uartdev); /**************************************************************************** * Private Data ****************************************************************************/ /* This structure provides the registry entry ID information that will be * used to associate the USB host CDC/ACM class to a connected USB * device. */ static const const struct usbhost_id_s g_id[2] = { { USB_CLASS_CDC, /* base */ CDC_SUBCLASS_NONE, /* subclass */ CDC_PROTO_NONE, /* proto */ 0, /* vid */ 0 /* pid */ }, { USB_CLASS_CDC, /* base */ CDC_SUBCLASS_ACM, /* subclass */ CDC_PROTO_ATM, /* proto */ 0, /* vid */ 0 /* pid */ } }; /* This is the USB host CDC/ACM class's registry entry */ static struct usbhost_registry_s g_cdcacm = { NULL, /* flink */ usbhost_create, /* create */ 2, /* nids */ &g_id[0] /* id[] */ }; /* Serial driver lower half interface */ static const struct uart_ops_s g_uart_ops = { usbhost_setup, /* setup */ usbhost_shutdown, /* shutdown */ usbhost_attach, /* attach */ usbhost_detach, /* detach */ usbhost_ioctl, /* ioctl */ NULL , /* receive */ usbhost_rxint, /* rxinit */ usbhost_rxavailable, /* rxavailable */ #ifdef CONFIG_SERIAL_IFLOWCONTROL usbhost_rxflowcontrol, /* rxflowcontrol */ #endif NULL, /* send */ usbhost_txint, /* txinit */ usbhost_txready, /* txready */ usbhost_txempty /* txempty */ }; /* This is an array of pre-allocated USB host CDC/ACM class instances */ #if CONFIG_USBHOST_CDCACM_NPREALLOC > 0 static struct usbhost_cdcacm_s g_prealloc[CONFIG_USBHOST_CDCACM_NPREALLOC]; #endif /* This is a list of free, pre-allocated USB host CDC/ACM class instances */ #if CONFIG_USBHOST_CDCACM_NPREALLOC > 0 static FAR struct usbhost_freestate_s *g_freelist; #endif /* This is a bitmap that is used to allocate device minor numbers /dev/ttyACM[n]. */ static uint32_t g_devinuse; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: usbhost_takesem * * Description: * This is just a wrapper to handle the annoying behavior of semaphore * waits that return due to the receipt of a signal. * ****************************************************************************/ static void usbhost_takesem(sem_t *sem) { int ret; do { /* Take the semaphore (perhaps waiting) */ ret = nxsem_wait(sem); /* The only case that an error should occur here is if the wait was * awakened by a signal. */ DEBUGASSERT(ret == OK || ret == -EINTR); } while (ret == -EINTR); } /**************************************************************************** * Name: usbhost_allocclass * * Description: * This is really part of the logic that implements the create() method * of struct usbhost_registry_s. This function allocates memory for one * new class instance. * * Input Parameters: * None * * Returned Value: * On success, this function will return a non-NULL instance of struct * usbhost_class_s. NULL is returned on failure; this function will * will fail only if there are insufficient resources to create another * USB host class instance. * ****************************************************************************/ #if CONFIG_USBHOST_CDCACM_NPREALLOC > 0 static FAR struct usbhost_cdcacm_s *usbhost_allocclass(void) { FAR struct usbhost_freestate_s *entry; irqstate_t flags; /* We may be executing from an interrupt handler so we need to take one of * our pre-allocated class instances from the free list. */ flags = enter_critical_section(); entry = g_freelist; if (entry) { g_freelist = entry->flink; } leave_critical_section(flags); uinfo("Allocated: %p\n", entry); return (FAR struct usbhost_cdcacm_s *)entry; } #else static FAR struct usbhost_cdcacm_s *usbhost_allocclass(void) { FAR struct usbhost_cdcacm_s *priv; /* We are not executing from an interrupt handler so we can just call * kmm_malloc() to get memory for the class instance. */ DEBUGASSERT(!up_interrupt_context()); priv = (FAR struct usbhost_cdcacm_s *)kmm_malloc(sizeof(struct usbhost_cdcacm_s)); uinfo("Allocated: %p\n", priv); return priv; } #endif /**************************************************************************** * Name: usbhost_freeclass * * Description: * Free a class instance previously allocated by usbhost_allocclass(). * * Input Parameters: * usbclass - A reference to the class instance to be freed. * * Returned Value: * None * ****************************************************************************/ #if CONFIG_USBHOST_CDCACM_NPREALLOC > 0 static void usbhost_freeclass(FAR struct usbhost_cdcacm_s *usbclass) { FAR struct usbhost_freestate_s *entry = (FAR struct usbhost_freestate_s *)usbclass; irqstate_t flags; DEBUGASSERT(entry != NULL); uinfo("Freeing: %p\n", entry); /* Just put the pre-allocated class structure back on the freelist */ flags = enter_critical_section(); entry->flink = g_freelist; g_freelist = entry; leave_critical_section(flags); } #else static void usbhost_freeclass(FAR struct usbhost_cdcacm_s *usbclass) { DEBUGASSERT(usbclass != NULL); /* Free the class instance (calling sched_kfree() in case we are executing * from an interrupt handler. */ uinfo("Freeing: %p\n", usbclass); sched_kfree(usbclass); } #endif /**************************************************************************** * Name: usbhost_devno_alloc * * Description: * Allocate a unique /dev/ttyACM[n] minor number in the range 0-31. * ****************************************************************************/ static int usbhost_devno_alloc(FAR struct usbhost_cdcacm_s *priv) { irqstate_t flags; int devno; flags = enter_critical_section(); for (devno = 0; devno < 32; devno++) { uint32_t bitno = 1 << devno; if ((g_devinuse & bitno) == 0) { g_devinuse |= bitno; priv->minor = devno; leave_critical_section(flags); return OK; } } leave_critical_section(flags); return -EMFILE; } /**************************************************************************** * Name: usbhost_devno_free * * Description: * Free a /dev/ttyACM[n] minor number so that it can be used. * ****************************************************************************/ static void usbhost_devno_free(FAR struct usbhost_cdcacm_s *priv) { int devno = priv->minor; if (devno >= 0 && devno < 32) { irqstate_t flags = enter_critical_section(); g_devinuse &= ~(1 << devno); leave_critical_section(flags); } } /**************************************************************************** * Name: usbhost_mkdevname * * Description: * Format a /dev/ttyACM[n] device name given a minor number. * ****************************************************************************/ static inline void usbhost_mkdevname(FAR struct usbhost_cdcacm_s *priv, FAR char *devname) { (void)snprintf(devname, DEV_NAMELEN, DEV_FORMAT, priv->minor); } /**************************************************************************** * Name: usbhost_linecoding_send * * Description: * Format and send the on EP0. * * Input Parameters: * arg - A reference to the class instance to be destroyed. * * Returned Value: * None * ****************************************************************************/ #ifdef HAVE_CTRL_INTERFACE static int usbhost_linecoding_send(FAR struct usbhost_cdcacm_s *priv) { FAR struct usbhost_hubport_s *hport; FAR struct cdc_linecoding_s *linecode; FAR struct usb_ctrlreq_s *ctrlreq; int ret; hport = priv->usbclass.hport; DEBUGASSERT(hport); /* Initialize the line coding structure */ linecode = (FAR struct cdc_linecoding_s *)priv->linecode; usbhost_putle32(linecode->baud, priv->baud); linecode->stop = (priv->stop2) ? 2 : 0; linecode->parity = priv->parity; linecode->nbits = priv->nbits; /* Initialize the control request */ ctrlreq = (FAR struct usb_ctrlreq_s *)priv->ctrlreq; ctrlreq->type = USB_DIR_OUT | USB_REQ_TYPE_CLASS | USB_REQ_RECIPIENT_INTERFACE; ctrlreq->req = ACM_SET_LINE_CODING; usbhost_putle16(ctrlreq->value, 0); usbhost_putle16(ctrlreq->index, priv->ctrlif); usbhost_putle16(ctrlreq->len, SIZEOF_CDC_LINECODING); /* And send the request */ ret = DRVR_CTRLOUT(hport->drvr, hport->ep0, ctrlreq, priv->linecode); if (ret < 0) { uerr("ERROR: DRVR_CTRLOUT failed: %d\n", ret); } return ret; } #endif /**************************************************************************** * Name: usbhost_notification_work * * Description: * Handle receipt of an asynchronous notification from the CDC/ACM device * * Input Parameters: * arg - The argument provided with the asynchronous I/O was setup * * Returned Value: * None * * Assumptions: * Probably called from an interrupt handler. * ****************************************************************************/ #ifdef HAVE_INTIN_ENDPOINT static void usbhost_notification_work(FAR void *arg) { FAR struct usbhost_cdcacm_s *priv; FAR struct usbhost_hubport_s *hport; FAR struct cdc_notification_s *inmsg; uint16_t value; uint16_t index; uint16_t len; int ret; priv = (FAR struct usbhost_cdcacm_s *)arg; DEBUGASSERT(priv); hport = priv->usbclass.hport; DEBUGASSERT(hport); /* Are we still connected? */ if (!priv->disconnected && priv->intin) { /* Yes.. Was an interrupt IN message received correctly? */ if (priv->nbytes >= 0) { /* Yes.. decode the notification */ inmsg = (FAR struct cdc_notification_s *)priv->notification; value = usbhost_getle16(inmsg->value); index = usbhost_getle16(inmsg->index); len = usbhost_getle16(inmsg->len); uinfo("type: %02x notification: %02x value: %04x index: %04x len: %04x\n", inmsg->type, inmsg->notification, value, index, len); /* We care only about the SerialState notification */ if ((inmsg->type == (USB_REQ_DIR_IN | USB_REQ_TYPE_CLASS | USB_REQ_RECIPIENT_INTERFACE)) && (inmsg->notification == ACM_SERIAL_STATE) && (value == 0) && (index == priv->ctrlif) && (len == 2)) { uint16_t state = usbhost_getle16(inmsg->data); /* And we care only about the state of the DCD and DSR in the * the notification. */ priv->dcd = ((state & CDC_UART_RXCARRIER) != 0); priv->dsr = ((state & CDC_UART_TXCARRIER) != 0); uinfo("ACM_SERIAL_STATE: DCD=%d DSR=%d\n", priv->dcd, priv->dsr); } } /* Setup to receive the next line status change event */ ret = DRVR_ASYNCH(hport->drvr, priv->intin, (FAR uint8_t *)priv->notification, MAX_NOTIFICATION, usbhost_notification_callback, priv); if (ret < 0) { uerr("ERROR: DRVR_ASYNCH failed: %d\n", ret); } } } #endif /**************************************************************************** * Name: usbhost_notification_callback * * Description: * Handle receipt of line status from the CDC/ACM device * * Input Parameters: * arg - The argument provided with the asynchronous I/O was setup * nbytes - The number of bytes actually transferred (or a negated errno * value; * * Returned Value: * None * * Assumptions: * Probably called from an interrupt handler. * ****************************************************************************/ #ifdef HAVE_INTIN_ENDPOINT static void usbhost_notification_callback(FAR void *arg, ssize_t nbytes) { FAR struct usbhost_cdcacm_s *priv = (FAR struct usbhost_cdcacm_s *)arg; uint32_t delay = 0; DEBUGASSERT(priv); /* Are we still connected? */ if (!priv->disconnected) { /* Check for a failure. On higher end host controllers, the * asynchronous transfer will pend until data is available (OHCI and * EHCI). On lower end host controllers (like STM32 and EFM32), the * transfer will fail immediately when the device NAKs the first * attempted interrupt IN transfer (with nbytes == -EAGAIN). In that * case (or in the case of other errors), we must fall back to * polling. */ DEBUGASSERT(nbytes >= INT16_MIN && nbytes <= INT16_MAX); priv->nbytes = (int16_t)nbytes; if (nbytes < 0) { /* This debug output is good to know, but really a nuisance for * those configurations where we have to fall back to polling. * FIX: Don't output the message is the result is -EAGAIN. */ #if defined(CONFIG_DEBUG_USB) && !defined(CONFIG_DEBUG_INFO) if (nbytes != -EAGAIN) #endif { uerr("ERROR: Transfer failed: %d\n", nbytes); } /* We don't know the nature of the failure, but we need to do all * that we can do to avoid a CPU hog error loop. * * Use the low-priority work queue and delay polling for the next * event. We want to use as little CPU bandwidth as possible in * this case. */ delay = USBHOST_CDCACM_NTDELAY; } /* Make sure that the work structure available. There is a remote * chance that this may collide with a device disconnection event. */ if (work_available(&priv->ntwork)) { (void)work_queue(HPWORK, &priv->ntwork, (worker_t)usbhost_notification_work, priv, delay); } } } #endif /************************************************************************************ * UART buffer data transfer ************************************************************************************/ /**************************************************************************** * Name: usbhost_txdata_work * * Description: * Send more OUT data to the attached CDC/ACM device. * * Input Parameters: * arg - A reference to the CDC/ACM class private data * * Returned Value: * None * ****************************************************************************/ static void usbhost_txdata_work(FAR void *arg) { FAR struct usbhost_cdcacm_s *priv; FAR struct usbhost_hubport_s *hport; FAR struct uart_dev_s *uartdev; FAR struct uart_buffer_s *txbuf; ssize_t nwritten; int txndx; int txtail; int ret; priv = (FAR struct usbhost_cdcacm_s *)arg; DEBUGASSERT(priv); hport = priv->usbclass.hport; DEBUGASSERT(hport); uartdev = &priv->uartdev; txbuf = &uartdev->xmit; /* Do nothing if TX transmission is disabled */ if (!priv->txena) { /* Terminate the work now *without* rescheduling */ return; } /* Loop until The UART TX buffer is empty (or we become disconnected) */ txtail = txbuf->tail; txndx = 0; while (txtail != txbuf->head && priv->txena && !priv->disconnected) { /* Copy data from the UART TX buffer until either 1) the UART TX * buffer has been emptied, or 2) the Bulk OUT buffer is full. */ txndx = 0; while (txtail != txbuf->head && txndx < priv->pktsize) { /* Copy the next byte */ priv->outbuf[txndx] = txbuf->buffer[txtail]; /* Increment counters and indices */ txndx++; if (++txtail >= txbuf->size) { txtail = 0; } } /* Save the updated tail pointer so that it cannot be sent again */ txbuf->tail = txtail; /* Bytes were removed from the TX buffer. Inform any waiters that * there is space available in the TX buffer. */ uart_datasent(uartdev); /* Send the filled TX buffer to the CDC/ACM device */ nwritten = DRVR_TRANSFER(hport->drvr, priv->bulkout, priv->outbuf, txndx); if (nwritten < 0) { /* The most likely reason for a failure is that CDC/ACM device * NAK'ed our packet OR that the device has been disconnected. * * Just break out of the loop, rescheduling the work (unless * the device is disconnected). */ uerr("ERROR: DRVR_TRANSFER for packet failed: %d\n", (int)nwritten); break; } } /* We get here because: 1) the UART TX buffer is empty and there is * nothing more to send, 2) the CDC/ACM device was not ready to accept our * data, or the device is no longer available. * * If the last packet sent was and even multiple of the packet size, then * we need to send a zero length packet (ZLP). */ if (txndx == priv->pktsize && !priv->disconnected) { /* Send the ZLP to the CDC/ACM device */ nwritten = DRVR_TRANSFER(hport->drvr, priv->bulkout, priv->outbuf, 0); if (nwritten < 0) { /* The most likely reason for a failure is that CDC/ACM device * NAK'ed our packet. */ uerr("ERROR: DRVR_TRANSFER for ZLP failed: %d\n", (int)nwritten); } } /* Check again if TX reception is enabled and that the device is still * connected. These states could have changed since we started the * transfer. */ if (priv->txena && !priv->disconnected) { /* Schedule TX data work to occur after a delay. */ ret = work_queue(LPWORK, &priv->txwork, usbhost_txdata_work, priv, USBHOST_CDCACM_TXDELAY); DEBUGASSERT(ret >= 0); UNUSED(ret); } } /**************************************************************************** * Name: usbhost_rxdata_work * * Description: * Get more IN data from the attached CDC/ACM device. * * Input Parameters: * arg - A reference to the CDC/ACM class private data * * Returned Value: * None * ****************************************************************************/ static void usbhost_rxdata_work(FAR void *arg) { FAR struct usbhost_cdcacm_s *priv; FAR struct usbhost_hubport_s *hport; FAR struct uart_dev_s *uartdev; FAR struct uart_buffer_s *rxbuf; ssize_t nread; int nxfrd; int nexthead; int rxndx; int ret; priv = (FAR struct usbhost_cdcacm_s *)arg; DEBUGASSERT(priv); hport = priv->usbclass.hport; DEBUGASSERT(hport); uartdev = &priv->uartdev; rxbuf = &uartdev->recv; /* Get the index in the RX packet buffer where we will take the first * byte of data. */ rxndx = priv->rxndx; nxfrd = 0; /* Get the index to the value of the UART RX buffer head AFTER the * first character has been stored. We need to know this in order * to test if the UART RX buffer is full. */ nexthead = rxbuf->head + 1; if (nexthead >= rxbuf->size) { nexthead = 0; } /* Loop until either: * * 1. The UART RX buffer is full * 2. There is no more data available from the CDC/ACM device * 3. RX rec */ #ifdef CONFIG_SERIAL_IFLOWCONTROL while (priv->rxena && priv->rts && !priv->disconnected) #else while (priv->rxena && !priv->disconnected) #endif { /* Stop now if there is no room for another character in the RX buffer. */ if (nexthead == rxbuf->tail) { /* Break out of the loop, rescheduling the work */ break; } /* Do we have any buffer RX data to transfer? */ if (priv->nrxbytes < 1) { /* No.. Read more data from the CDC/ACM device */ nread = DRVR_TRANSFER(hport->drvr, priv->bulkin, priv->inbuf, priv->pktsize); if (nread < 0) { /* The most likely reason for a failure is that the has no * data available now and NAK'ed the IN token OR that the * transfer was cancelled because the device was disconnected. * * Just break out of the loop, rescheduling the work (if the * device was not disconnected. */ uerr("ERROR: DRVR_TRANSFER for packet failed: %d\n", (int)nread); break; } /* Save the number of bytes read. This might be zero if * a Zero Length Packet (ZLP) is received. The ZLP is * part of the bulk transfer protocol, but otherwise of * no interest to us. */ priv->nrxbytes = (uint16_t)nread; rxndx = 0; /* Ignore ZLPs */ if (nread == 0) { continue; } } /* Transfer one byte from the RX packet buffer into UART RX buffer */ rxbuf->buffer[rxbuf->head] = priv->inbuf[rxndx]; nxfrd++; /* Save the updated indices */ rxbuf->head = nexthead; priv->rxndx = rxndx; /* Update the head point for for the next pass through the loop * handling. If nexthead incremented to rxbuf->tail, then the * RX buffer will and we will exit the loop at the top. */ if (++nexthead >= rxbuf->size) { nexthead = 0; } /* Increment the index in the USB IN packet buffer. If the * index becomes equal to the number of bytes in the buffer, then * we have consumed all of the RX data. */ if (++rxndx >= priv->nrxbytes) { /* In that case set the number of bytes in the buffer to zero. * This will force re-reading on the next time through the loop. */ priv->nrxbytes = 0; priv->rxndx = 0; /* Inform any waiters there there is new incoming data available. */ uart_datareceived(uartdev); nxfrd = 0; } } /* We break out to here: 1) the UART RX buffer is full, 2) the CDC/ACM * device is not ready to provide us with more serial data, or 3) the * device has been disconnected. * * Check if the device is still available: RX enabled, no RX flow * control in effect, and that the device is not disconnected. These * states could have changed since we started the transfer. */ #ifdef CONFIG_SERIAL_IFLOWCONTROL if (priv->rxena && priv->rts && work_available(&priv->rxwork) && !priv->disconnected) #else if (priv->rxena && work_available(&priv->rxwork) && !priv->disconnected) #endif { /* Schedule RX data reception work to occur after a delay. This will * affect our responsive in certain cases. The delayed work, however, * will be cancelled and replaced with immediate work when the upper * layer demands more data. */ ret = work_queue(LPWORK, &priv->rxwork, usbhost_rxdata_work, priv, USBHOST_CDCACM_RXDELAY); DEBUGASSERT(ret >= 0); UNUSED(ret); } /* If any bytes were added to the buffer, inform any waiters there there * is new incoming data available. */ if (nxfrd) { uart_datareceived(uartdev); } } /**************************************************************************** * Name: usbhost_destroy * * Description: * The USB CDC/ACM device has been disconnected and the reference count * on the USB host class instance has gone to 1.. Time to destroy the USB * host class instance. * * Input Parameters: * arg - A reference to the class instance to be destroyed. * * Returned Value: * None * ****************************************************************************/ static void usbhost_destroy(FAR void *arg) { FAR struct usbhost_cdcacm_s *priv = (FAR struct usbhost_cdcacm_s *)arg; FAR struct usbhost_hubport_s *hport; char devname[DEV_NAMELEN]; DEBUGASSERT(priv != NULL && priv->usbclass.hport != NULL); hport = priv->usbclass.hport; uinfo("crefs: %d\n", priv->crefs); /* Unregister the serial lower half driver */ usbhost_mkdevname(priv, devname); #warning Missing logic /* Release the device name used by this connection */ usbhost_devno_free(priv); /* Free the allocated endpoints */ if (priv->bulkout) { DRVR_EPFREE(hport->drvr, priv->bulkout); } if (priv->bulkin) { DRVR_EPFREE(hport->drvr, priv->bulkin); } #ifdef HAVE_INTIN_ENDPOINT if (priv->intin) { DRVR_EPFREE(hport->drvr, priv->intin); } #endif /* Free any transfer buffers */ usbhost_free_buffers(priv); /* Destroy the semaphores */ nxsem_destroy(&priv->exclsem); /* Disconnect the USB host device */ DRVR_DISCONNECT(hport->drvr, hport); /* Free the function address assigned to this device */ usbhost_devaddr_destroy(hport, hport->funcaddr); hport->funcaddr = 0; /* And free the class instance. */ usbhost_freeclass(priv); } /**************************************************************************** * Name: usbhost_cfgdesc * * Description: * This function implements the connect() method of struct * usbhost_class_s. This method is a callback into the class * implementation. It is used to provide the device's configuration * descriptor to the class so that the class may initialize properly * * Input Parameters: * priv - The USB host class instance. * configdesc - A pointer to a uint8_t buffer container the configuration * descriptor. * desclen - The length in bytes of the configuration descriptor. * * Returned Value: * On success, zero (OK) is returned. On a failure, a negated errno value is * returned indicating the nature of the failure * * Assumptions: * This function will *not* be called from an interrupt handler. * ****************************************************************************/ static int usbhost_cfgdesc(FAR struct usbhost_cdcacm_s *priv, FAR const uint8_t *configdesc, int desclen) { FAR struct usbhost_hubport_s *hport; FAR struct usb_cfgdesc_s *cfgdesc; FAR struct usb_desc_s *desc; FAR struct usbhost_epdesc_s bindesc; FAR struct usbhost_epdesc_s boutdesc; FAR struct usbhost_epdesc_s iindesc; int remaining; uint8_t found = 0; uint8_t currif = 0; int ret; DEBUGASSERT(priv != NULL && priv->usbclass.hport && configdesc != NULL && desclen >= sizeof(struct usb_cfgdesc_s)); hport = priv->usbclass.hport; /* Keep the compiler from complaining about uninitialized variables */ memset(&bindesc, 0, sizeof(struct usbhost_epdesc_s)); memset(&boutdesc, 0, sizeof(struct usbhost_epdesc_s)); memset(&iindesc, 0, sizeof(struct usbhost_epdesc_s)); /* Verify that we were passed a configuration descriptor */ cfgdesc = (FAR struct usb_cfgdesc_s *)configdesc; if (cfgdesc->type != USB_DESC_TYPE_CONFIG) { return -EINVAL; } /* Get the total length of the configuration descriptor (little endian). * It might be a good check to get the number of interfaces here too. */ remaining = (int)usbhost_getle16(cfgdesc->totallen); /* Skip to the next entry descriptor */ configdesc += cfgdesc->len; remaining -= cfgdesc->len; /* Loop where there are more descriptors to examine */ while (remaining >= sizeof(struct usb_desc_s)) { /* What is the next descriptor? */ desc = (FAR struct usb_desc_s *)configdesc; switch (desc->type) { /* Interface descriptor. The CDC/ACM device may include two * interfaces: * * 1) A data interface which consists of two endpoints (bulk in + * bulk out) and * 2) A control interface which consists of one interrupt in * endpoint. */ case USB_DESC_TYPE_INTERFACE: { FAR struct usb_ifdesc_s *ifdesc = (FAR struct usb_ifdesc_s *)configdesc; uinfo("Interface descriptor: class: %d subclass: %d proto: %d\n", ifdesc->classid, ifdesc->subclass, ifdesc->protocol); DEBUGASSERT(remaining >= USB_SIZEOF_IFDESC); /* Check for the CDC/ACM data interface */ if (ifdesc->classid == USB_CLASS_CDC_DATA && (found & USBHOST_DATAIF_FOUND) == 0) { /* Save the data interface number and mark that the data * interface found has been found. */ priv->dataif = ifdesc->ifno; found |= USBHOST_DATAIF_FOUND; currif = USBHOST_DATAIF_FOUND; } #ifdef HAVE_CTRL_INTERFACE else if (ifdesc->classid == USB_CLASS_CDC && (found & USBHOST_CTRLIF_FOUND) == 0) { /* Otherwise, tentatively assume that this is the control * interface. */ priv->ctrlif = ifdesc->ifno; currif = USBHOST_CTRLIF_FOUND; } #endif else { /* Its something else */ currif = 0; } } break; /* Endpoint descriptor. We expect two bulk endpoints, an IN and an * OUT. */ case USB_DESC_TYPE_ENDPOINT: { FAR struct usb_epdesc_s *epdesc = (FAR struct usb_epdesc_s *)configdesc; uinfo("Endpoint descriptor: currif: %02x attr: %02x\n", currif, epdesc->attr); DEBUGASSERT(remaining >= USB_SIZEOF_EPDESC); /* Check for a bulk endpoint. */ if (currif == USBHOST_DATAIF_FOUND && (epdesc->attr & USB_EP_ATTR_XFERTYPE_MASK) == USB_EP_ATTR_XFER_BULK) { /* Yes.. it is a bulk endpoint. IN or OUT? */ if (USB_ISEPOUT(epdesc->addr)) { /* It is an OUT bulk endpoint. There should be only one * bulk OUT endpoint. */ if ((found & USBHOST_BULKOUT_FOUND) != 0) { /* Oops.. more than one endpoint. We don't know * what to do with this. */ return -EINVAL; } found |= USBHOST_BULKOUT_FOUND; /* Save the bulk OUT endpoint information */ boutdesc.hport = hport; boutdesc.addr = epdesc->addr & USB_EP_ADDR_NUMBER_MASK; boutdesc.in = false; boutdesc.xfrtype = USB_EP_ATTR_XFER_BULK; boutdesc.interval = epdesc->interval; boutdesc.mxpacketsize = usbhost_getle16(epdesc->mxpacketsize); uinfo("Bulk OUT EP addr:%d mxpacketsize:%d\n", boutdesc.addr, boutdesc.mxpacketsize); } else { /* It is an IN bulk endpoint. There should be only one * bulk IN endpoint. */ if ((found & USBHOST_BULKIN_FOUND) != 0) { /* Oops.. more than one endpoint. We don't know * what to do with this. */ return -EINVAL; } found |= USBHOST_BULKIN_FOUND; /* Save the bulk IN endpoint information */ bindesc.hport = hport; bindesc.addr = epdesc->addr & USB_EP_ADDR_NUMBER_MASK; bindesc.in = 1; bindesc.xfrtype = USB_EP_ATTR_XFER_BULK; bindesc.interval = epdesc->interval; bindesc.mxpacketsize = usbhost_getle16(epdesc->mxpacketsize); uinfo("Bulk IN EP addr:%d mxpacketsize:%d\n", bindesc.addr, bindesc.mxpacketsize); } } #ifdef HAVE_CTRL_INTERFACE /* Check for an interrupt IN endpoint. */ else if (currif == USBHOST_CTRLIF_FOUND && (epdesc->attr & USB_EP_ATTR_XFERTYPE_MASK) == USB_EP_ATTR_XFER_INT) { /* Yes.. it is a interrupt endpoint. IN or OUT? */ if (USB_ISEPIN(epdesc->addr)) { #ifdef HAVE_INTIN_ENDPOINT /* It is an IN interrupt endpoint. There should be only one * interrupt IN endpoint. */ if ((found & USBHOST_INTIN_FOUND) != 0) { /* Oops.. more than one. We don't know what to do * with this. */ return -EINVAL; } /* Let's pick this interface as the one and only control * interface. */ found |= (USBHOST_CTRLIF_FOUND | USBHOST_INTIN_FOUND); /* Save the bulk OUT endpoint information */ iindesc.hport = hport; iindesc.addr = epdesc->addr & USB_EP_ADDR_NUMBER_MASK; iindesc.in = false; iindesc.xfrtype = USB_EP_ATTR_XFER_INT; iindesc.interval = epdesc->interval; iindesc.mxpacketsize = usbhost_getle16(epdesc->mxpacketsize); uinfo("Interrupt IN EP addr:%d mxpacketsize:%d\n", boutdesc.addr, boutdesc.mxpacketsize); #else found |= USBHOST_CTRLIF_FOUND; #endif } } #endif } break; /* Other descriptors are just ignored for now */ default: break; } /* If we found everything we need with this interface, then break out * of the loop early. */ if (found == USBHOST_ALLFOUND) { break; } /* Increment the address of the next descriptor */ configdesc += desc->len; remaining -= desc->len; } /* Sanity checking... did we find all of things that we needed for the * basic CDC/ACM data itnerface? NOTE: that the Control interface with * the Interrupt IN endpoint is optional. */ if ((found & USBHOST_MINFOUND) != USBHOST_MINFOUND) { uerr("ERROR: Found DATA IF:%s BULK IN:%s BULK OUT:%s\n", (found & USBHOST_DATAIF_FOUND) != 0 ? "YES" : "NO", (found & USBHOST_BULKIN_FOUND) != 0 ? "YES" : "NO", (found & USBHOST_BULKOUT_FOUND) != 0 ? "YES" : "NO"); return -EINVAL; } /* We are good... Allocate the endpoints */ ret = DRVR_EPALLOC(hport->drvr, &boutdesc, &priv->bulkout); if (ret < 0) { uerr("ERROR: Failed to allocate Bulk OUT endpoint\n"); return ret; } ret = DRVR_EPALLOC(hport->drvr, &bindesc, &priv->bulkin); if (ret < 0) { uerr("ERROR: Failed to allocate Bulk IN endpoint\n"); (void)DRVR_EPFREE(hport->drvr, priv->bulkout); return ret; } #ifdef HAVE_INTIN_ENDPOINT /* The control interface with interrupt IN endpoint is optional */ if ((found & USBHOST_HAVE_CTRLIF) == USBHOST_HAVE_CTRLIF) { ret = DRVR_EPALLOC(hport->drvr, &iindesc, &priv->intin); if (ret < 0) { uerr("ERROR: Failed to allocate Interrupt IN endpoint\n"); priv->intin = NULL; } } #endif uinfo("Endpoints allocated\n"); return OK; } /**************************************************************************** * Name: usbhost_getle16 * * Description: * Get a (possibly unaligned) 16-bit little endian value. * * Input Parameters: * val - A pointer to the first byte of the little endian value. * * Returned Value: * A uint16_t representing the whole 16-bit integer value * ****************************************************************************/ static inline uint16_t usbhost_getle16(const uint8_t *val) { return (uint16_t)val[1] << 8 | (uint16_t)val[0]; } /**************************************************************************** * Name: usbhost_getbe16 * * Description: * Get a (possibly unaligned) 16-bit big endian value. * * Input Parameters: * val - A pointer to the first byte of the big endian value. * * Returned Value: * A uint16_t representing the whole 16-bit integer value * ****************************************************************************/ static inline uint16_t usbhost_getbe16(const uint8_t *val) { return (uint16_t)val[0] << 8 | (uint16_t)val[1]; } /**************************************************************************** * Name: usbhost_putle16 * * Description: * Put a (possibly unaligned) 16-bit little endian value. * * Input Parameters: * dest - A pointer to the first byte to save the little endian value. * val - The 16-bit value to be saved. * * Returned Value: * None * ****************************************************************************/ static void usbhost_putle16(uint8_t *dest, uint16_t val) { dest[0] = val & 0xff; /* Little endian means LS byte first in byte stream */ dest[1] = val >> 8; } /**************************************************************************** * Name: usbhost_putle32 * * Description: * Put a (possibly unaligned) 32-bit little endian value. * * Input Parameters: * dest - A pointer to the first byte to save the little endian value. * val - The 32-bit value to be saved. * * Returned Value: * None * ****************************************************************************/ #ifdef HAVE_CTRL_INTERFACE static void usbhost_putle32(uint8_t *dest, uint32_t val) { /* Little endian means LS halfword first in byte stream */ usbhost_putle16(dest, (uint16_t)(val & 0xffff)); usbhost_putle16(dest+2, (uint16_t)(val >> 16)); } #endif /**************************************************************************** * Name: usbhost_alloc_buffers * * Description: * Allocate transfer buffer memory. * * Input Parameters: * priv - A reference to the class instance. * * Returned Value: * On sucess, zero (OK) is returned. On failure, an negated errno value * is returned to indicate the nature of the failure. * ****************************************************************************/ static int usbhost_alloc_buffers(FAR struct usbhost_cdcacm_s *priv) { FAR struct usbhost_hubport_s *hport; size_t maxlen; int ret; DEBUGASSERT(priv != NULL && priv->usbclass.hport != NULL && priv->linecode == NULL); hport = priv->usbclass.hport; /* Allocate memory for control requests */ ret = DRVR_ALLOC(hport->drvr, (FAR uint8_t **)&priv->ctrlreq, &maxlen); if (ret < 0) { uerr("ERROR: DRVR_ALLOC of ctrlreq failed: %d\n", ret); goto errout; } DEBUGASSERT(maxlen >= sizeof(struct usb_ctrlreq_s)); /* Allocate buffer for sending line coding data. */ ret = DRVR_IOALLOC(hport->drvr, &priv->linecode, sizeof(struct cdc_linecoding_s)); if (ret < 0) { uerr("ERROR: DRVR_IOALLOC of line coding failed: %d (%d bytes)\n", ret, sizeof(struct cdc_linecoding_s)); goto errout; } #ifdef HAVE_INTIN_ENDPOINT /* Allocate (optional) buffer for receiving line status data. */ if (priv->intin) { ret = DRVR_IOALLOC(hport->drvr, &priv->notification, MAX_NOTIFICATION); if (ret < 0) { uerr("ERROR: DRVR_IOALLOC of line status failed: %d (%d bytes)\n", ret, MAX_NOTIFICATION); goto errout; } } #endif /* Set the size of Bulk IN and OUT buffers to the max packet size */ priv->pktsize = (hport->speed == USB_SPEED_HIGH) ? 512 : 64; /* Allocate a RX buffer for Bulk IN transfers */ ret = DRVR_IOALLOC(hport->drvr, &priv->inbuf, priv->pktsize); if (ret < 0) { uerr("ERROR: DRVR_IOALLOC of Bulk IN buffer failed: %d (%d bytes)\n", ret, priv->pktsize); goto errout; } /* Allocate a TX buffer for Bulk IN transfers */ ret = DRVR_IOALLOC(hport->drvr, &priv->outbuf, priv->pktsize); if (ret < 0) { uerr("ERROR: DRVR_IOALLOC of Bulk OUT buffer failed: %d (%d bytes)\n", ret, priv->pktsize); goto errout; } return OK; errout: usbhost_free_buffers(priv); return ret; } /**************************************************************************** * Name: usbhost_free_buffers * * Description: * Free transfer buffer memory. * * Input Parameters: * priv - A reference to the class instance. * * Returned Value: * None * ****************************************************************************/ static void usbhost_free_buffers(FAR struct usbhost_cdcacm_s *priv) { FAR struct usbhost_hubport_s *hport; DEBUGASSERT(priv != NULL && priv->usbclass.hport != NULL); hport = priv->usbclass.hport; if (priv->ctrlreq) { (void)DRVR_FREE(hport->drvr, priv->ctrlreq); } if (priv->linecode) { (void)DRVR_IOFREE(hport->drvr, priv->linecode); } if (priv->notification) { (void)DRVR_IOFREE(hport->drvr, priv->notification); } if (priv->inbuf) { (void)DRVR_IOFREE(hport->drvr, priv->inbuf); } if (priv->outbuf) { (void)DRVR_IOFREE(hport->drvr, priv->outbuf); } priv->pktsize = 0; priv->ctrlreq = NULL; priv->linecode = NULL; priv->notification = NULL; priv->inbuf = NULL; priv->outbuf = NULL; } /**************************************************************************** * struct usbhost_registry_s methods ****************************************************************************/ /**************************************************************************** * Name: usbhost_create * * Description: * This function implements the create() method of struct usbhost_registry_s. * The create() method is a callback into the class implementation. It is * used to (1) create a new instance of the USB host class state and to (2) * bind a USB host driver "session" to the class instance. Use of this * create() method will support environments where there may be multiple * USB ports and multiple USB devices simultaneously connected. * * Input Parameters: * hport - The hub port that manages the new class instance. * id - In the case where the device supports multiple base classes, * subclasses, or protocols, this specifies which to configure for. * * Returned Value: * On success, this function will return a non-NULL instance of struct * usbhost_class_s that can be used by the USB host driver to communicate * with the USB host class. NULL is returned on failure; this function * will fail only if the hport input parameter is NULL or if there are * insufficient resources to create another USB host class instance. * ****************************************************************************/ static FAR struct usbhost_class_s * usbhost_create(FAR struct usbhost_hubport_s *hport, FAR const struct usbhost_id_s *id) { FAR struct usbhost_cdcacm_s *priv; FAR struct uart_dev_s *uartdev; /* Allocate a USB host CDC/ACM class instance */ priv = usbhost_allocclass(); if (priv) { /* Initialize the allocated CDC/ACM class instance */ memset(priv, 0, sizeof(struct usbhost_cdcacm_s)); /* Assign a device number to this class instance */ if (usbhost_devno_alloc(priv) == OK) { /* Initialize class method function pointers */ priv->usbclass.hport = hport; priv->usbclass.connect = usbhost_connect; priv->usbclass.disconnected = usbhost_disconnected; /* The initial reference count is 1... One reference is held by the driver */ priv->crefs = 1; /* Initialize semaphores (this works okay in the interrupt context) */ nxsem_init(&priv->exclsem, 0, 1); /* Set up the serial lower-half interface */ uartdev = &priv->uartdev; uartdev->recv.size = CONFIG_USBHOST_CDCACM_RXBUFSIZE; uartdev->recv.buffer = priv->rxbuffer; uartdev->xmit.size = CONFIG_USBHOST_CDCACM_TXBUFSIZE; uartdev->xmit.buffer = priv->txbuffer; uartdev->ops = &g_uart_ops; uartdev->priv = priv; /* Set up the initial line status */ priv->baud = CONFIG_USBHOST_CDCACM_BAUD; priv->nbits = CONFIG_USBHOST_CDCACM_BITS; priv->parity = CONFIG_USBHOST_CDCACM_PARITY; priv->stop2 = CONFIG_USBHOST_CDCACM_2STOP; #ifdef CONFIG_SERIAL_IFLOWCONTROL priv->rts = true; #endif /* Return the instance of the USB CDC/ACM class */ return &priv->usbclass; } } /* An error occurred. Free the allocation and return NULL on all failures */ if (priv) { usbhost_freeclass(priv); } return NULL; } /**************************************************************************** * struct usbhost_class_s methods ****************************************************************************/ /**************************************************************************** * Name: usbhost_connect * * Description: * This function implements the connect() method of struct * usbhost_class_s. This method is a callback into the class * implementation. It is used to provide the device's configuration * descriptor to the class so that the class may initialize properly * * Input Parameters: * usbclass - The USB host class entry previously obtained from a call to * create(). * configdesc - A pointer to a uint8_t buffer container the configuration * descriptor. * desclen - The length in bytes of the configuration descriptor. * * Returned Value: * On success, zero (OK) is returned. On a failure, a negated errno value is * returned indicating the nature of the failure * * NOTE that the class instance remains valid upon return with a failure. It is * the responsibility of the higher level enumeration logic to call * CLASS_DISCONNECTED to free up the class driver resources. * * Assumptions: * - This function will *not* be called from an interrupt handler. * - If this function returns an error, the USB host controller driver * must call to DISCONNECTED method to recover from the error * ****************************************************************************/ static int usbhost_connect(FAR struct usbhost_class_s *usbclass, FAR const uint8_t *configdesc, int desclen) { FAR struct usbhost_cdcacm_s *priv = (FAR struct usbhost_cdcacm_s *)usbclass; #ifdef HAVE_INTIN_ENDPOINT FAR struct usbhost_hubport_s *hport; #endif char devname[DEV_NAMELEN]; int ret; DEBUGASSERT(priv != NULL && configdesc != NULL && desclen >= sizeof(struct usb_cfgdesc_s)); #ifdef HAVE_INTIN_ENDPOINT hport = priv->usbclass.hport; DEBUGASSERT(hport); #endif /* Get exclusive access to the device structure */ usbhost_takesem(&priv->exclsem); /* Increment the reference count. This will prevent usbhost_destroy() from * being called asynchronously if the device is removed. */ priv->crefs++; DEBUGASSERT(priv->crefs == 2); /* Parse the configuration descriptor to get the bulk I/O endpoints */ ret = usbhost_cfgdesc(priv, configdesc, desclen); if (ret < 0) { uerr("ERROR: usbhost_cfgdesc() failed: %d\n", ret); goto errout; } /* Set aside a transfer buffer for exclusive use by the CDC/ACM driver */ ret = usbhost_alloc_buffers(priv); if (ret < 0) { uerr("ERROR: Failed to allocate transfer buffer\n"); goto errout; } #ifdef HAVE_CTRL_INTERFACE /* Send the initial line encoding */ ret = usbhost_linecoding_send(priv); if (ret < 0) { uerr("ERROR: usbhost_linecoding_send() failed: %d\n", ret); } #endif /* Register the lower half serial instance with the upper half serial * driver */ usbhost_mkdevname(priv, devname); uinfo("Register device: %s\n", devname); ret = uart_register(devname, &priv->uartdev); if (ret < 0) { uerr("ERROR: uart_register() failed: %d\n", ret); goto errout; } #ifdef HAVE_INTIN_ENDPOINT /* Do we have an interrupt IN endpoint? */ if (priv->intin) { /* Begin monitoring of port status change events */ uinfo("Start notification monitoring\n"); ret = DRVR_ASYNCH(hport->drvr, priv->intin, (FAR uint8_t *)priv->notification, MAX_NOTIFICATION, usbhost_notification_callback, priv); if (ret < 0) { uerr("ERROR: DRVR_ASYNCH failed: %d\n", ret); } } #endif errout: /* Decrement the reference count. We incremented the reference count * above so that usbhost_destroy() could not be called. We now have to * be concerned about asynchronous modification of crefs because the * serial driver has been registered. */ DEBUGASSERT(priv->crefs >= 2); priv->crefs--; /* Release the semaphore... there is a race condition here. * Decrementing the reference count and releasing the semaphore * allows usbhost_destroy() to execute (on the worker thread); * the class driver instance could get destroyed before we are * ready to handle it! */ usbhost_givesem(&priv->exclsem); return ret; } /**************************************************************************** * Name: usbhost_disconnected * * Description: * This function implements the disconnected() method of struct * usbhost_class_s. This method is a callback into the class * implementation. It is used to inform the class that the USB device has * been disconnected. * * Input Parameters: * usbclass - The USB host class entry previously obtained from a call to * create(). * * Returned Value: * On success, zero (OK) is returned. On a failure, a negated errno value * is returned indicating the nature of the failure * * Assumptions: * This function may be called from an interrupt handler. * ****************************************************************************/ static int usbhost_disconnected(struct usbhost_class_s *usbclass) { FAR struct usbhost_cdcacm_s *priv = (FAR struct usbhost_cdcacm_s *)usbclass; FAR struct usbhost_hubport_s *hport; irqstate_t flags; int ret; DEBUGASSERT(priv != NULL && priv->usbclass.hport != NULL); hport = priv->usbclass.hport; /* Set an indication to any users of the CDC/ACM device that the device * is no longer available. */ flags = enter_critical_section(); priv->disconnected = true; /* Let the upper half driver know that serial device is no longer * connected. */ uart_connected(&priv->uartdev, false); /* Cancel any ongoing Bulk transfers */ ret = DRVR_CANCEL(hport->drvr, priv->bulkin); if (ret < 0) { uerr("ERROR: Bulk IN DRVR_CANCEL failed: %d\n", ret); } ret = DRVR_CANCEL(hport->drvr, priv->bulkout); if (ret < 0) { uerr("ERROR: Bulk OUT DRVR_CANCEL failed: %d\n", ret); } #ifdef HAVE_INTIN_ENDPOINT /* Cancel any pending asynchronous I/O */ if (priv->intin) { int ret = DRVR_CANCEL(hport->drvr, priv->intin); if (ret < 0) { uerr("ERROR: Interrupt IN DRVR_CANCEL failed: %d\n", ret); } } #endif /* Now check the number of references on the class instance. If it is one, * then we can free the class instance now. Otherwise, we will have to * wait until the holders of the references free them by closing the * serial driver. */ uinfo("crefs: %d\n", priv->crefs); if (priv->crefs == 1) { /* Destroy the class instance. If we are executing from an interrupt * handler, then defer the destruction to the worker thread. * Otherwise, destroy the instance now. */ if (up_interrupt_context()) { /* Destroy the instance on the worker thread. */ uinfo("Queuing destruction: worker %p->%p\n", priv->ntwork.worker, usbhost_destroy); DEBUGASSERT(work_available(&priv->ntwork)); (void)work_queue(HPWORK, &priv->ntwork, usbhost_destroy, priv, 0); } else { /* Do the work now */ usbhost_destroy(priv); } } leave_critical_section(flags); return OK; } /**************************************************************************** * Serial Lower-Half Interfaces ****************************************************************************/ /**************************************************************************** * Name: usbhost_setup * * Description: * Configure the USART baud, bits, parity, etc. This method is called the * first time that the serial port is opened. * ****************************************************************************/ static int usbhost_setup(FAR struct uart_dev_s *uartdev) { FAR struct usbhost_cdcacm_s *priv; irqstate_t flags; int ret; uinfo("Entry\n"); DEBUGASSERT(uartdev && uartdev->priv); priv = (FAR struct usbhost_cdcacm_s *)uartdev->priv; /* Make sure that we have exclusive access to the private data structure */ DEBUGASSERT(priv->crefs > 0 && priv->crefs < USBHOST_MAX_CREFS); usbhost_takesem(&priv->exclsem); /* Check if the CDC/ACM device is still connected. We need to disable * interrupts momentarily to assure that there are no asynchronous * isconnect events. */ flags = enter_critical_section(); if (priv->disconnected) { /* No... the block driver is no longer bound to the class. That means that * the USB CDC/ACM device is no longer connected. Refuse any further * attempts to open the driver. */ ret = -ENODEV; } else { /* Otherwise, just increment the reference count on the driver */ priv->crefs++; ret = OK; } leave_critical_section(flags); usbhost_givesem(&priv->exclsem); return ret; } /**************************************************************************** * Name: usbhost_shutdown * * Description: * Disable the USART. This method is called when the serial * port is closed * ****************************************************************************/ static void usbhost_shutdown(FAR struct uart_dev_s *uartdev) { FAR struct usbhost_cdcacm_s *priv; irqstate_t flags; uinfo("Entry\n"); DEBUGASSERT(uartdev && uartdev->priv); priv = (FAR struct usbhost_cdcacm_s *)uartdev->priv; /* Decrement the reference count on the block driver */ DEBUGASSERT(priv->crefs > 1); usbhost_takesem(&priv->exclsem); priv->crefs--; /* Release the semaphore. The following operations when crefs == 1 are * safe because we know that there is no outstanding open references to * the block driver. */ usbhost_givesem(&priv->exclsem); /* We need to disable interrupts momentarily to assure that there are * no asynchronous disconnect events. */ flags = enter_critical_section(); /* Check if the USB CDC/ACM device is still connected. If the * CDC/ACM device is not connected and the reference count just * decremented to one, then unregister the block driver and free * the class instance. */ if (priv->crefs <= 1 && priv->disconnected) { /* Destroy the class instance */ DEBUGASSERT(priv->crefs == 1); usbhost_destroy(priv); } leave_critical_section(flags); } /**************************************************************************** * Name: usbhost_attach * * Description: * Configure the USART to operation in interrupt driven mode. This method is * called when the serial port is opened. Normally, this is just after the * the setup() method is called, however, the serial console may operate in * a non-interrupt driven mode during the boot phase. * * RX and TX interrupts are not enabled when by the attach method (unless the * hardware supports multiple levels of interrupt enabling). The RX and TX * interrupts are not enabled until the txint() and rxint() methods are called. * ****************************************************************************/ static int usbhost_attach(FAR struct uart_dev_s *uartdev) { return OK; } /**************************************************************************** * Name: usbhost_detach * * Description: * Detach USART interrupts. This method is called when the serial port is * closed normally just before the shutdown method is called. The exception * is the serial console which is never shutdown. * ****************************************************************************/ static void usbhost_detach(FAR struct uart_dev_s *uartdev) { } /**************************************************************************** * Name: usbhost_ioctl * * Description: * All ioctl calls will be routed through this method * ****************************************************************************/ static int usbhost_ioctl(FAR struct file *filep, int cmd, unsigned long arg) { struct inode *inode; struct usbhost_cdcacm_s *priv; int ret; uinfo("Entry\n"); DEBUGASSERT(filep && filep->f_inode); inode = filep->f_inode; DEBUGASSERT(inode && inode->i_private); priv = (FAR struct usbhost_cdcacm_s *)inode->i_private; /* Check if the CDC/ACM device is still connected */ if (priv->disconnected) { /* No... the serial device has been disconnecgted. Refuse to process * any ioctl commands. */ ret = -ENODEV; } else { /* Process the IOCTL by command */ usbhost_takesem(&priv->exclsem); switch (cmd) { #ifdef CONFIG_SERIAL_TIOCSERGSTRUCT case TIOCSERGSTRUCT: { FAR struct usbhost_cdcacm_s *user = (FAR struct usbhost_cdcacm_s *)arg; if (!user) { ret = -EINVAL; } else { memcpy(user, uartdev, sizeof(struct usbhost_cdcacm_s)); } } break; #endif #ifdef CONFIG_SERIAL_TERMIOS case TCGETS: { FAR struct termios *termiosp = (FAR struct termios *)arg; if (!termiosp) { ret = -EINVAL; break; } cfsetispeed(termiosp, priv->baud); termiosp->c_cflag = ((priv->parity != 0) ? PARENB : 0) | ((priv->parity == 1) ? PARODD : 0) | ((priv->stop2) ? CSTOPB : 0) #ifdef CONFIG_SERIAL_OFLOWCONTROL | ((priv->oflow) ? CCTS_OFLOW : 0) #endif #ifdef CONFIG_SERIAL_IFLOWCONTROL | ((priv->iflow) ? CRTS_IFLOW : 0) #endif ; switch (priv->bits) { case 5: termiosp->c_cflag |= CS5; break; case 6: termiosp->c_cflag |= CS6; break; case 7: termiosp->c_cflag |= CS7; break; default: /* 16-bits? */ case 8: termiosp->c_cflag |= CS8; break; } } break; case TCSETS: { FAR struct termios *termiosp = (FAR struct termios *)arg; #ifdef CONFIG_SERIAL_IFLOWCONTROL bool iflow; #endif if (!termiosp) { ret = -EINVAL; break; } if (termiosp->c_cflag & PARENB) { priv->parity = (termiosp->c_cflag & PARODD) ? 1 : 2; } else { priv->parity = 0; } priv->stopbits2 = (termiosp->c_cflag & CSTOPB) != 0; #ifdef CONFIG_SERIAL_OFLOWCONTROL priv->oflow = (termiosp->c_cflag & CCTS_OFLOW) != 0; #endif #ifdef CONFIG_SERIAL_IFLOWCONTROL iflow = priv->iflow; priv->iflow = (termiosp->c_cflag & CRTS_IFLOW) != 0; #endif switch (termiosp->c_flag & CSIZE) { case C5: priv->bits = 5; break; case C6: priv->bits = 6; break; case C7: priv->bits = 7; break; default: case C8: priv->bits = 8; break; } /* Note that only cfgetispeed is used because we have knowledge * that only one speed is supported. */ priv->baud = cfgetispeed(termiosp); #ifdef CONFIG_SERIAL_IFLOWCONTROL /* Set RTS if input flow control changed */ if (iflow != !priv->iflow) { priv->rts = true; } #endif #ifdef HAVE_CTRL_INTERFACE /* Effect the changes immediately - note that we do not implement * TCSADRAIN / TCSAFLUSH */ ret = usbhost_linecoding_send(priv); #endif } break; #endif /* CONFIG_SERIAL_TERMIOS */ #ifdef CONFIG_USBHOST_CDCACM_BREAKS case TIOCSBRK: /* BSD compatibility: Turn break on, unconditionally */ { #warning Missing logic } break; case TIOCCBRK: /* BSD compatibility: Turn break off, unconditionally */ { #warning Missing logic } break; #endif default: ret = -ENOTTY; break; } usbhost_givesem(&priv->exclsem); } return ret; } /**************************************************************************** * Name: usbhost_rxint * * Description: * Call to enable or disable RX interrupts * ****************************************************************************/ static void usbhost_rxint(FAR struct uart_dev_s *uartdev, bool enable) { FAR struct usbhost_cdcacm_s *priv; int ret; DEBUGASSERT(uartdev && uartdev->priv); priv = (FAR struct usbhost_cdcacm_s *)uartdev->priv; /* Are we enabling or disabling RX reception? */ if (enable && !priv->rxena) { /* Cancel any pending, delayed RX data reception work */ (void)work_cancel(LPWORK, &priv->rxwork); /* Restart immediate RX data reception work (unless RX flow control * is in* effect. */ #ifdef CONFIG_SERIAL_IFLOWCONTROL if (priv->rts) #endif { ret = work_queue(LPWORK, &priv->rxwork, usbhost_rxdata_work, priv, 0); DEBUGASSERT(ret >= 0); UNUSED(ret); } } else if (!enable && priv->rxena) { /* Cancel any pending RX data reception work */ (void)work_cancel(LPWORK, &priv->rxwork); } /* Save the new RX enable state */ priv->rxena = enable; } /**************************************************************************** * Name: usbhost_rxavailable * * Description: * Return true if the receive buffer is not empty * ****************************************************************************/ static bool usbhost_rxavailable(FAR struct uart_dev_s *uartdev) { FAR struct usbhost_cdcacm_s *priv; DEBUGASSERT(uartdev && uartdev->priv); priv = (FAR struct usbhost_cdcacm_s *)uartdev->priv; return (priv->nrxbytes > 0); } /**************************************************************************** * Name: usbhost_rxflowcontrol * * Description: * Called when Rx buffer is full (or exceeds configured watermark levels * if CONFIG_SERIAL_IFLOWCONTROL_WATERMARKS is defined). * Return true if UART activated RX flow control to block more incoming * data * * Input parameters: * uartdev - UART device instance * nbuffered - the number of characters currently buffered * (if CONFIG_SERIAL_IFLOWCONTROL_WATERMARKS is * not defined the value will be 0 for an empty buffer or the * defined buffer size for a full buffer) * upper - true indicates the upper watermark was crossed where * false indicates the lower watermark has been crossed * * Returned Value: * true if RX flow control activated. * ****************************************************************************/ #ifdef CONFIG_SERIAL_IFLOWCONTROL static bool usbhost_rxflowcontrol(FAR struct uart_dev_s *uartdev, unsigned int nbuffered, bool upper) { FAR struct usbhost_cdcacm_s *priv; bool newrts; int ret; DEBUGASSERT(uartdev && uartdev->priv); priv = (FAR struct usbhost_cdcacm_s *)uartdev->priv /* Is RX flow control enabled? */ if (!priv->iflow) { /* Now.. make sure that RTS is set */ priv->rts = true; return false; } /* Are we enabling or disabling RX flow control? */ if (priv->rts && upper) { /* RX flow control is not in effect (RTS is true) but we have just * crossed the upper threshold, meaning that we should now clear * RTS. */ priv->rts = false; /* Cancel any pending RX data reception work */ (void)work_cancel(LPWORK, &priv->rxwork) return true; } else if (!priv->rts && !upper) { /* RX flow control is in effect (RTS is false) and we have just * crossed the lower threshold, meaning that we should now set * RTS. */ priv->rts = true; /* Restart RX data reception work flow unless RX reception is * disabled. */ if (priv->rxena && work_available(&priv->rxwork)) { ret = work_queue(LPWORK, &priv->rxwork, usbhost_rxdata_work, priv, 0); DEBUGASSERT(ret >= 0); UNUSED(ret); } return false; } } #endif /**************************************************************************** * Name: usbhost_txint * * Description: * Call to enable or disable TX interrupts * ****************************************************************************/ static void usbhost_txint(FAR struct uart_dev_s *uartdev, bool enable) { FAR struct usbhost_cdcacm_s *priv; int ret; DEBUGASSERT(uartdev && uartdev->priv); priv = (FAR struct usbhost_cdcacm_s *)uartdev->priv; /* Are we enabling or disabling TX transmission? */ if (enable && !priv->txena) { /* Cancel any pending, delayed TX data transmission work */ (void)work_cancel(LPWORK, &priv->txwork); /* Restart immediate TX data transmission work */ ret = work_queue(LPWORK, &priv->txwork, usbhost_txdata_work, priv, 0); DEBUGASSERT(ret >= 0); UNUSED(ret); } else if (!enable && priv->txena) { /* Cancel any pending TX data transmission work */ (void)work_cancel(LPWORK, &priv->txwork); } /* Save the new RX enable state */ priv->txena = enable; } /**************************************************************************** * Name: usbhost_txready * * Description: * Return true if the transmit data register is not full. * ****************************************************************************/ static bool usbhost_txready(FAR struct uart_dev_s *uartdev) { return true; } /**************************************************************************** * Name: usbhost_txempty * * Description: * Return true if the transmit data buffer is empty * ****************************************************************************/ static bool usbhost_txempty(FAR struct uart_dev_s *uartdev) { return true; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: usbhost_cdcacm_initialize * * Description: * Initialize the USB host CDC/ACM class. This function should be called * be platform-specific code in order to initialize and register support * for the USB host CDC/ACM class. * * Input Parameters: * None * * Returned Value: * On success this function will return zero (OK); A negated errno value * will be returned on failure. * ****************************************************************************/ int usbhost_cdcacm_initialize(void) { /* If we have been configured to use pre-allocated CDC/ACM class instances, * then place all of the pre-allocated USB host CDC/ACM class instances * into a free list. */ #if CONFIG_USBHOST_CDCACM_NPREALLOC > 0 FAR struct usbhost_freestate_s *entry; int i; g_freelist = NULL; for (i = 0; i < CONFIG_USBHOST_CDCACM_NPREALLOC; i++) { entry = (FAR struct usbhost_freestate_s *)&g_prealloc[i]; entry->flink = g_freelist; g_freelist = entry; } #endif /* Advertise our availability to support (certain) CDC/ACM devices */ return usbhost_registerclass(&g_cdcacm); } #endif /* CONFIG_USBHOST_CDCACM */