+#ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
+
+/* initial values for parport regs */
+#define DCR_INIT_VAL 0x0c /* SLCTIN, nINIT */
+#define ECR_INIT_VAL 0x00 /* SPP mode */
+
+struct urbtracker {
+ struct mos7715_parport *mos_parport;
+ struct list_head urblist_entry;
+ struct kref ref_count;
+ struct urb *urb;
+};
+
+enum mos7715_pp_modes {
+ SPP = 0<<5,
+ PS2 = 1<<5, /* moschip calls this 'NIBBLE' mode */
+ PPF = 2<<5, /* moschip calls this 'CB-FIFO mode */
+};
+
+struct mos7715_parport {
+ struct parport *pp; /* back to containing struct */
+ struct kref ref_count; /* to instance of this struct */
+ struct list_head deferred_urbs; /* list deferred async urbs */
+ struct list_head active_urbs; /* list async urbs in flight */
+ spinlock_t listlock; /* protects list access */
+ bool msg_pending; /* usb sync call pending */
+ struct completion syncmsg_compl; /* usb sync call completed */
+ struct tasklet_struct urb_tasklet; /* for sending deferred urbs */
+ struct usb_serial *serial; /* back to containing struct */
+ __u8 shadowECR; /* parallel port regs... */
+ __u8 shadowDCR;
+ atomic_t shadowDSR; /* updated in int-in callback */
+};
+
+/* lock guards against dereferencing NULL ptr in parport ops callbacks */
+static DEFINE_SPINLOCK(release_lock);
+
+enum mos_regs {
+ THR, /* serial port regs */
+ RHR,
+ IER,
+ FCR,
+ ISR,
+ LCR,
+ MCR,
+ LSR,
+ MSR,
+ SPR,
+ DLL,
+ DLM,
+ DPR, /* parallel port regs */
+ DSR,
+ DCR,
+ ECR,
+ SP1_REG, /* device control regs */
+ SP2_REG, /* serial port 2 (7720 only) */
+ PP_REG,
+ SP_CONTROL_REG,
+};
+
+/*
+ * Return the correct value for the Windex field of the setup packet
+ * for a control endpoint message. See the 7715 datasheet.
+ */
+static inline __u16 get_reg_index(enum mos_regs reg)
+{
+ static const __u16 mos7715_index_lookup_table[] = {
+ 0x00, /* THR */
+ 0x00, /* RHR */
+ 0x01, /* IER */
+ 0x02, /* FCR */
+ 0x02, /* ISR */
+ 0x03, /* LCR */
+ 0x04, /* MCR */
+ 0x05, /* LSR */
+ 0x06, /* MSR */
+ 0x07, /* SPR */
+ 0x00, /* DLL */
+ 0x01, /* DLM */
+ 0x00, /* DPR */
+ 0x01, /* DSR */
+ 0x02, /* DCR */
+ 0x0a, /* ECR */
+ 0x01, /* SP1_REG */
+ 0x02, /* SP2_REG (7720 only) */
+ 0x04, /* PP_REG (7715 only) */
+ 0x08, /* SP_CONTROL_REG */
+ };
+ return mos7715_index_lookup_table[reg];
+}
+
+/*
+ * Return the correct value for the upper byte of the Wvalue field of
+ * the setup packet for a control endpoint message.
+ */
+static inline __u16 get_reg_value(enum mos_regs reg)
+{
+ if (reg >= SP1_REG) /* control reg */
+ return 0x0000;
+ else /* parallel port reg (7715 only) */
+ return 0x0100;
+}
+
+/*
+ * Write data byte to the specified device register. The data is embedded in
+ * the value field of the setup packet.
+ */
+static int write_parport_reg(struct mos7715_parport *mos_parport,
+ enum mos_regs reg, __u8 data)
+{
+ struct usb_serial *serial = mos_parport->serial;
+ struct usb_device *usbdev = serial->dev;
+ unsigned int pipe = usb_sndctrlpipe(usbdev, 0);
+ __u8 request = (__u8)0x0e;
+ __u8 requesttype = (__u8)0x40;
+ __u16 value = get_reg_value(reg) + data;
+ __u16 index = get_reg_index(reg);
+ __u16 size = 0;
+ int status;
+ status = usb_control_msg(usbdev, pipe, request, requesttype, value,
+ index, NULL, size, MOS_WDR_TIMEOUT);
+ if (status < 0)
+ dev_err(&usbdev->dev,
+ "mos7720: usb_control_msg() failed: %d", status);
+ return status;
+}
+
+/*
+ * Read data byte from the specified device register. The data returned by the
+ * device is embedded in the value field of the setup packet.
+ */
+static int read_parport_reg(struct mos7715_parport *mos_parport,
+ enum mos_regs reg, __u8 *data)
+{
+ struct usb_device *usbdev = mos_parport->serial->dev;
+ unsigned int pipe = usb_rcvctrlpipe(usbdev, 0);
+ __u8 request = (__u8)0x0d;
+ __u8 requesttype = (__u8)0xc0;
+ __u16 value = get_reg_value(reg);
+ __u16 index = get_reg_index(reg);
+ __u16 size = 1;
+ int status = usb_control_msg(usbdev, pipe, request, requesttype, value,
+ index, data, size, MOS_WDR_TIMEOUT);
+ if (status < 0)
+ dev_err(&usbdev->dev,
+ "mos7720: usb_control_msg() failed: %d", status);
+ return status;
+}
+
+static inline int mos7715_change_mode(struct mos7715_parport *mos_parport,
+ enum mos7715_pp_modes mode)
+{
+ mos_parport->shadowECR = mode;
+ write_parport_reg(mos_parport, ECR, mos_parport->shadowECR);
+ return 0;
+}
+
+static void destroy_mos_parport(struct kref *kref)
+{
+ struct mos7715_parport *mos_parport =
+ container_of(kref, struct mos7715_parport, ref_count);
+
+ dbg("%s called", __func__);
+ kfree(mos_parport);
+}
+
+static void destroy_urbtracker(struct kref *kref)
+{
+ struct urbtracker *urbtrack =
+ container_of(kref, struct urbtracker, ref_count);
+ struct mos7715_parport *mos_parport = urbtrack->mos_parport;
+ dbg("%s called", __func__);
+ usb_free_urb(urbtrack->urb);
+ kfree(urbtrack);
+ kref_put(&mos_parport->ref_count, destroy_mos_parport);
+}
+
+/*
+ * This runs as a tasklet when sending an urb in a non-blocking parallel
+ * port callback had to be deferred because the disconnect mutex could not be
+ * obtained at the time.
+ */
+static void send_deferred_urbs(unsigned long _mos_parport)
+{
+ int ret_val;
+ unsigned long flags;
+ struct mos7715_parport *mos_parport = (void *)_mos_parport;
+ struct urbtracker *urbtrack;
+ struct list_head *cursor, *next;
+
+ dbg("%s called", __func__);
+
+ /* if release function ran, game over */
+ if (unlikely(mos_parport->serial == NULL))
+ return;
+
+ /* try again to get the mutex */
+ if (!mutex_trylock(&mos_parport->serial->disc_mutex)) {
+ dbg("%s: rescheduling tasklet", __func__);
+ tasklet_schedule(&mos_parport->urb_tasklet);
+ return;
+ }
+
+ /* if device disconnected, game over */
+ if (unlikely(mos_parport->serial->disconnected)) {
+ mutex_unlock(&mos_parport->serial->disc_mutex);
+ return;
+ }
+
+ spin_lock_irqsave(&mos_parport->listlock, flags);
+ if (list_empty(&mos_parport->deferred_urbs)) {
+ spin_unlock_irqrestore(&mos_parport->listlock, flags);
+ mutex_unlock(&mos_parport->serial->disc_mutex);
+ dbg("%s: deferred_urbs list empty", __func__);
+ return;
+ }
+
+ /* move contents of deferred_urbs list to active_urbs list and submit */
+ list_for_each_safe(cursor, next, &mos_parport->deferred_urbs)
+ list_move_tail(cursor, &mos_parport->active_urbs);
+ list_for_each_entry(urbtrack, &mos_parport->active_urbs,
+ urblist_entry) {
+ ret_val = usb_submit_urb(urbtrack->urb, GFP_ATOMIC);
+ dbg("%s: urb submitted", __func__);
+ if (ret_val) {
+ dev_err(&mos_parport->serial->dev->dev,
+ "usb_submit_urb() failed: %d", ret_val);
+ list_del(&urbtrack->urblist_entry);
+ kref_put(&urbtrack->ref_count, destroy_urbtracker);
+ }
+ }
+ spin_unlock_irqrestore(&mos_parport->listlock, flags);
+ mutex_unlock(&mos_parport->serial->disc_mutex);
+}
+
+/* callback for parallel port control urbs submitted asynchronously */
+static void async_complete(struct urb *urb)
+{
+ struct urbtracker *urbtrack = urb->context;
+ int status = urb->status;
+ dbg("%s called", __func__);
+ if (unlikely(status))
+ dbg("%s - nonzero urb status received: %d", __func__, status);
+
+ /* remove the urbtracker from the active_urbs list */
+ spin_lock(&urbtrack->mos_parport->listlock);
+ list_del(&urbtrack->urblist_entry);
+ spin_unlock(&urbtrack->mos_parport->listlock);
+ kref_put(&urbtrack->ref_count, destroy_urbtracker);
+}
+
+static int write_parport_reg_nonblock(struct mos7715_parport *mos_parport,
+ enum mos_regs reg, __u8 data)
+{
+ struct urbtracker *urbtrack;
+ int ret_val;
+ unsigned long flags;
+ struct usb_ctrlrequest setup;
+ struct usb_serial *serial = mos_parport->serial;
+ struct usb_device *usbdev = serial->dev;
+ dbg("%s called", __func__);
+
+ /* create and initialize the control urb and containing urbtracker */
+ urbtrack = kmalloc(sizeof(struct urbtracker), GFP_ATOMIC);
+ if (urbtrack == NULL) {
+ dev_err(&usbdev->dev, "out of memory");
+ return -ENOMEM;
+ }
+ kref_get(&mos_parport->ref_count);
+ urbtrack->mos_parport = mos_parport;
+ urbtrack->urb = usb_alloc_urb(0, GFP_ATOMIC);
+ if (urbtrack->urb == NULL) {
+ dev_err(&usbdev->dev, "out of urbs");
+ kfree(urbtrack);
+ return -ENOMEM;
+ }
+ setup.bRequestType = (__u8)0x40;
+ setup.bRequest = (__u8)0x0e;
+ setup.wValue = get_reg_value(reg);
+ setup.wIndex = get_reg_index(reg);
+ setup.wLength = 0;
+ usb_fill_control_urb(urbtrack->urb, usbdev,
+ usb_sndctrlpipe(usbdev, 0),
+ (unsigned char *)&setup,
+ NULL, 0, async_complete, urbtrack);
+ kref_init(&urbtrack->ref_count);
+ INIT_LIST_HEAD(&urbtrack->urblist_entry);
+
+ /*
+ * get the disconnect mutex, or add tracker to the deferred_urbs list
+ * and schedule a tasklet to try again later
+ */
+ if (!mutex_trylock(&serial->disc_mutex)) {
+ spin_lock_irqsave(&mos_parport->listlock, flags);
+ list_add_tail(&urbtrack->urblist_entry,
+ &mos_parport->deferred_urbs);
+ spin_unlock_irqrestore(&mos_parport->listlock, flags);
+ tasklet_schedule(&mos_parport->urb_tasklet);
+ dbg("tasklet scheduled");
+ return 0;
+ }
+
+ /* bail if device disconnected */
+ if (serial->disconnected) {
+ kref_put(&urbtrack->ref_count, destroy_urbtracker);
+ mutex_unlock(&serial->disc_mutex);
+ return -ENODEV;
+ }
+
+ /* add the tracker to the active_urbs list and submit */
+ spin_lock_irqsave(&mos_parport->listlock, flags);
+ list_add_tail(&urbtrack->urblist_entry, &mos_parport->active_urbs);
+ spin_unlock_irqrestore(&mos_parport->listlock, flags);
+ ret_val = usb_submit_urb(urbtrack->urb, GFP_ATOMIC);
+ mutex_unlock(&serial->disc_mutex);
+ if (ret_val) {
+ dev_err(&usbdev->dev,
+ "%s: submit_urb() failed: %d", __func__, ret_val);
+ spin_lock_irqsave(&mos_parport->listlock, flags);
+ list_del(&urbtrack->urblist_entry);
+ spin_unlock_irqrestore(&mos_parport->listlock, flags);
+ kref_put(&urbtrack->ref_count, destroy_urbtracker);
+ return ret_val;
+ }
+ return 0;
+}
+
+/*
+ * This is the the common top part of all parallel port callback operations that
+ * send synchronous messages to the device. This implements convoluted locking
+ * that avoids two scenarios: (1) a port operation is called after usbserial
+ * has called our release function, at which point struct mos7715_parport has
+ * been destroyed, and (2) the device has been disconnected, but usbserial has
+ * not called the release function yet because someone has a serial port open.
+ * The shared release_lock prevents the first, and the mutex and disconnected
+ * flag maintained by usbserial covers the second. We also use the msg_pending
+ * flag to ensure that all synchronous usb messgage calls have completed before
+ * our release function can return.
+ */
+static int parport_prologue(struct parport *pp)
+{
+ struct mos7715_parport *mos_parport;
+
+ spin_lock(&release_lock);
+ mos_parport = pp->private_data;
+ if (unlikely(mos_parport == NULL)) {
+ /* release fn called, port struct destroyed */
+ spin_unlock(&release_lock);
+ return -1;
+ }
+ mos_parport->msg_pending = true; /* synch usb call pending */
+ INIT_COMPLETION(mos_parport->syncmsg_compl);
+ spin_unlock(&release_lock);
+
+ mutex_lock(&mos_parport->serial->disc_mutex);
+ if (mos_parport->serial->disconnected) {
+ /* device disconnected */
+ mutex_unlock(&mos_parport->serial->disc_mutex);
+ mos_parport->msg_pending = false;
+ complete(&mos_parport->syncmsg_compl);
+ return -1;
+ }
+
+ return 0;
+}
+
+/*
+ * This is the the common bottom part of all parallel port functions that send
+ * synchronous messages to the device.
+ */
+static inline void parport_epilogue(struct parport *pp)
+{
+ struct mos7715_parport *mos_parport = pp->private_data;
+ mutex_unlock(&mos_parport->serial->disc_mutex);
+ mos_parport->msg_pending = false;
+ complete(&mos_parport->syncmsg_compl);
+}
+
+static void parport_mos7715_write_data(struct parport *pp, unsigned char d)
+{
+ struct mos7715_parport *mos_parport = pp->private_data;
+ dbg("%s called: %2.2x", __func__, d);
+ if (parport_prologue(pp) < 0)
+ return;
+ mos7715_change_mode(mos_parport, SPP);
+ write_parport_reg(mos_parport, DPR, (__u8)d);
+ parport_epilogue(pp);
+}
+
+static unsigned char parport_mos7715_read_data(struct parport *pp)
+{
+ struct mos7715_parport *mos_parport = pp->private_data;
+ unsigned char d;
+ dbg("%s called", __func__);
+ if (parport_prologue(pp) < 0)
+ return 0;
+ read_parport_reg(mos_parport, DPR, &d);
+ parport_epilogue(pp);
+ return d;
+}
+
+static void parport_mos7715_write_control(struct parport *pp, unsigned char d)
+{
+ struct mos7715_parport *mos_parport = pp->private_data;
+ __u8 data;
+ dbg("%s called: %2.2x", __func__, d);
+ if (parport_prologue(pp) < 0)
+ return;
+ data = ((__u8)d & 0x0f) | (mos_parport->shadowDCR & 0xf0);
+ write_parport_reg(mos_parport, DCR, data);
+ mos_parport->shadowDCR = data;
+ parport_epilogue(pp);
+}
+
+static unsigned char parport_mos7715_read_control(struct parport *pp)
+{
+ struct mos7715_parport *mos_parport = pp->private_data;
+ __u8 dcr;
+ dbg("%s called", __func__);
+ spin_lock(&release_lock);
+ mos_parport = pp->private_data;
+ if (unlikely(mos_parport == NULL)) {
+ spin_unlock(&release_lock);
+ return 0;
+ }
+ dcr = mos_parport->shadowDCR & 0x0f;
+ spin_unlock(&release_lock);
+ return dcr;
+}
+
+static unsigned char parport_mos7715_frob_control(struct parport *pp,
+ unsigned char mask,
+ unsigned char val)
+{
+ struct mos7715_parport *mos_parport = pp->private_data;
+ __u8 dcr;
+ dbg("%s called", __func__);
+ mask &= 0x0f;
+ val &= 0x0f;
+ if (parport_prologue(pp) < 0)
+ return 0;
+ mos_parport->shadowDCR = (mos_parport->shadowDCR & (~mask)) ^ val;
+ write_parport_reg(mos_parport, DCR, mos_parport->shadowDCR);
+ dcr = mos_parport->shadowDCR & 0x0f;
+ parport_epilogue(pp);
+ return dcr;
+}
+
+static unsigned char parport_mos7715_read_status(struct parport *pp)
+{
+ unsigned char status;
+ struct mos7715_parport *mos_parport = pp->private_data;
+ dbg("%s called", __func__);
+ spin_lock(&release_lock);
+ mos_parport = pp->private_data;
+ if (unlikely(mos_parport == NULL)) { /* release called */
+ spin_unlock(&release_lock);
+ return 0;
+ }
+ status = atomic_read(&mos_parport->shadowDSR) & 0xf8;
+ spin_unlock(&release_lock);
+ return status;
+}
+
+static void parport_mos7715_enable_irq(struct parport *pp)
+{
+ dbg("%s called", __func__);
+}
+static void parport_mos7715_disable_irq(struct parport *pp)
+{
+ dbg("%s called", __func__);
+}
+
+static void parport_mos7715_data_forward(struct parport *pp)
+{
+ struct mos7715_parport *mos_parport = pp->private_data;
+ dbg("%s called", __func__);
+ if (parport_prologue(pp) < 0)
+ return;
+ mos7715_change_mode(mos_parport, PS2);
+ mos_parport->shadowDCR &= ~0x20;
+ write_parport_reg(mos_parport, DCR, mos_parport->shadowDCR);
+ parport_epilogue(pp);
+}
+
+static void parport_mos7715_data_reverse(struct parport *pp)
+{
+ struct mos7715_parport *mos_parport = pp->private_data;
+ dbg("%s called", __func__);
+ if (parport_prologue(pp) < 0)
+ return;
+ mos7715_change_mode(mos_parport, PS2);
+ mos_parport->shadowDCR |= 0x20;
+ write_parport_reg(mos_parport, DCR, mos_parport->shadowDCR);
+ parport_epilogue(pp);
+}
+
+static void parport_mos7715_init_state(struct pardevice *dev,
+ struct parport_state *s)
+{
+ dbg("%s called", __func__);
+ s->u.pc.ctr = DCR_INIT_VAL;
+ s->u.pc.ecr = ECR_INIT_VAL;
+}
+
+/* N.B. Parport core code requires that this function not block */
+static void parport_mos7715_save_state(struct parport *pp,
+ struct parport_state *s)
+{
+ struct mos7715_parport *mos_parport;
+ dbg("%s called", __func__);
+ spin_lock(&release_lock);
+ mos_parport = pp->private_data;
+ if (unlikely(mos_parport == NULL)) { /* release called */
+ spin_unlock(&release_lock);
+ return;
+ }
+ s->u.pc.ctr = mos_parport->shadowDCR;
+ s->u.pc.ecr = mos_parport->shadowECR;
+ spin_unlock(&release_lock);
+}
+
+/* N.B. Parport core code requires that this function not block */
+static void parport_mos7715_restore_state(struct parport *pp,
+ struct parport_state *s)
+{
+ struct mos7715_parport *mos_parport;
+ dbg("%s called", __func__);
+ spin_lock(&release_lock);
+ mos_parport = pp->private_data;
+ if (unlikely(mos_parport == NULL)) { /* release called */
+ spin_unlock(&release_lock);
+ return;
+ }
+ write_parport_reg_nonblock(mos_parport, DCR, mos_parport->shadowDCR);
+ write_parport_reg_nonblock(mos_parport, ECR, mos_parport->shadowECR);
+ spin_unlock(&release_lock);
+}
+
+static size_t parport_mos7715_write_compat(struct parport *pp,
+ const void *buffer,
+ size_t len, int flags)
+{
+ int retval;
+ struct mos7715_parport *mos_parport = pp->private_data;
+ int actual_len;
+ dbg("%s called: %u chars", __func__, (unsigned int)len);
+ if (parport_prologue(pp) < 0)
+ return 0;
+ mos7715_change_mode(mos_parport, PPF);
+ retval = usb_bulk_msg(mos_parport->serial->dev,
+ usb_sndbulkpipe(mos_parport->serial->dev, 2),
+ (void *)buffer, len, &actual_len,
+ MOS_WDR_TIMEOUT);
+ parport_epilogue(pp);
+ if (retval) {
+ dev_err(&mos_parport->serial->dev->dev,
+ "mos7720: usb_bulk_msg() failed: %d", retval);
+ return 0;
+ }
+ return actual_len;
+}
+
+static struct parport_operations parport_mos7715_ops = {
+ .owner = THIS_MODULE,
+ .write_data = parport_mos7715_write_data,
+ .read_data = parport_mos7715_read_data,
+
+ .write_control = parport_mos7715_write_control,
+ .read_control = parport_mos7715_read_control,
+ .frob_control = parport_mos7715_frob_control,
+
+ .read_status = parport_mos7715_read_status,
+
+ .enable_irq = parport_mos7715_enable_irq,
+ .disable_irq = parport_mos7715_disable_irq,
+
+ .data_forward = parport_mos7715_data_forward,
+ .data_reverse = parport_mos7715_data_reverse,
+
+ .init_state = parport_mos7715_init_state,
+ .save_state = parport_mos7715_save_state,
+ .restore_state = parport_mos7715_restore_state,
+
+ .compat_write_data = parport_mos7715_write_compat,
+
+ .nibble_read_data = parport_ieee1284_read_nibble,
+ .byte_read_data = parport_ieee1284_read_byte,
+};
+
+/*
+ * Allocate and initialize parallel port control struct, initialize
+ * the parallel port hardware device, and register with the parport subsystem.
+ */
+static int mos7715_parport_init(struct usb_serial *serial)
+{
+ struct mos7715_parport *mos_parport;
+
+ /* allocate and initialize parallel port control struct */
+ mos_parport = kzalloc(sizeof(struct mos7715_parport), GFP_KERNEL);
+ if (mos_parport == NULL) {
+ dbg("mos7715_parport_init: kzalloc failed");
+ return -ENOMEM;
+ }
+ mos_parport->msg_pending = false;
+ kref_init(&mos_parport->ref_count);
+ spin_lock_init(&mos_parport->listlock);
+ INIT_LIST_HEAD(&mos_parport->active_urbs);
+ INIT_LIST_HEAD(&mos_parport->deferred_urbs);
+ usb_set_serial_data(serial, mos_parport); /* hijack private pointer */
+ mos_parport->serial = serial;
+ tasklet_init(&mos_parport->urb_tasklet, send_deferred_urbs,
+ (unsigned long) mos_parport);
+ init_completion(&mos_parport->syncmsg_compl);
+
+ /* cycle parallel port reset bit */
+ write_parport_reg(mos_parport, PP_REG, (__u8)0x80);
+ write_parport_reg(mos_parport, PP_REG, (__u8)0x00);
+
+ /* initialize device registers */
+ mos_parport->shadowDCR = DCR_INIT_VAL;
+ write_parport_reg(mos_parport, DCR, mos_parport->shadowDCR);
+ mos_parport->shadowECR = ECR_INIT_VAL;
+ write_parport_reg(mos_parport, ECR, mos_parport->shadowECR);
+
+ /* register with parport core */
+ mos_parport->pp = parport_register_port(0, PARPORT_IRQ_NONE,
+ PARPORT_DMA_NONE,
+ &parport_mos7715_ops);
+ if (mos_parport->pp == NULL) {
+ dev_err(&serial->interface->dev,
+ "Could not register parport\n");
+ kref_put(&mos_parport->ref_count, destroy_mos_parport);
+ return -EIO;
+ }
+ mos_parport->pp->private_data = mos_parport;
+ mos_parport->pp->modes = PARPORT_MODE_COMPAT | PARPORT_MODE_PCSPP;
+ mos_parport->pp->dev = &serial->interface->dev;
+ parport_announce_port(mos_parport->pp);
+
+ return 0;
+}
+#endif /* CONFIG_USB_SERIAL_MOS7715_PARPORT */