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path: root/drivers/staging/b3dfg/b3dfg.c
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Diffstat (limited to 'drivers/staging/b3dfg/b3dfg.c')
-rw-r--r--drivers/staging/b3dfg/b3dfg.c1119
1 files changed, 1119 insertions, 0 deletions
diff --git a/drivers/staging/b3dfg/b3dfg.c b/drivers/staging/b3dfg/b3dfg.c
new file mode 100644
index 00000000000..0348072b3ab
--- /dev/null
+++ b/drivers/staging/b3dfg/b3dfg.c
@@ -0,0 +1,1119 @@
+ /*
+ * Brontes PCI frame grabber driver
+ *
+ * Copyright (C) 2008 3M Company
+ * Contact: Justin Bronder <jsbronder@brontes3d.com>
+ * Original Authors: Daniel Drake <ddrake@brontes3d.com>
+ * Duane Griffin <duaneg@dghda.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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/ioctl.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/types.h>
+#include <linux/cdev.h>
+#include <linux/list.h>
+#include <linux/poll.h>
+#include <linux/wait.h>
+#include <linux/mm.h>
+#include <linux/version.h>
+#include <linux/uaccess.h>
+
+static unsigned int b3dfg_nbuf = 2;
+
+module_param_named(buffer_count, b3dfg_nbuf, uint, 0444);
+
+MODULE_PARM_DESC(buffer_count, "Number of buffers (min 2, default 2)\n");
+
+MODULE_AUTHOR("Daniel Drake <ddrake@brontes3d.com>");
+MODULE_DESCRIPTION("Brontes frame grabber driver");
+MODULE_LICENSE("GPL");
+
+#define DRIVER_NAME "b3dfg"
+#define B3DFG_MAX_DEVS 4
+#define B3DFG_FRAMES_PER_BUFFER 3
+
+#define B3DFG_BAR_REGS 0
+#define B3DFG_REGS_LENGTH 0x10000
+
+#define B3DFG_IOC_MAGIC 0xb3 /* dfg :-) */
+#define B3DFG_IOCGFRMSZ _IOR(B3DFG_IOC_MAGIC, 1, int)
+#define B3DFG_IOCTNUMBUFS _IO(B3DFG_IOC_MAGIC, 2)
+#define B3DFG_IOCTTRANS _IO(B3DFG_IOC_MAGIC, 3)
+#define B3DFG_IOCTQUEUEBUF _IO(B3DFG_IOC_MAGIC, 4)
+#define B3DFG_IOCTPOLLBUF _IOWR(B3DFG_IOC_MAGIC, 5, struct b3dfg_poll)
+#define B3DFG_IOCTWAITBUF _IOWR(B3DFG_IOC_MAGIC, 6, struct b3dfg_wait)
+#define B3DFG_IOCGWANDSTAT _IOR(B3DFG_IOC_MAGIC, 7, int)
+
+enum {
+ /* number of 4kb pages per frame */
+ B3D_REG_FRM_SIZE = 0x0,
+
+ /* bit 0: set to enable interrupts
+ * bit 1: set to enable cable status change interrupts */
+ B3D_REG_HW_CTRL = 0x4,
+
+ /* bit 0-1 - 1-based ID of next pending frame transfer (0 = none)
+ * bit 2 indicates the previous DMA transfer has completed
+ * bit 3 indicates wand cable status change
+ * bit 8:15 - counter of number of discarded triplets */
+ B3D_REG_DMA_STS = 0x8,
+
+ /* bit 0: wand status (1 = present, 0 = disconnected) */
+ B3D_REG_WAND_STS = 0xc,
+
+ /* bus address for DMA transfers. lower 2 bits must be zero because DMA
+ * works with 32 bit word size. */
+ B3D_REG_EC220_DMA_ADDR = 0x8000,
+
+ /* bit 20:0 - number of 32 bit words to be transferred
+ * bit 21:31 - reserved */
+ B3D_REG_EC220_TRF_SIZE = 0x8004,
+
+ /* bit 0 - error bit
+ * bit 1 - interrupt bit (set to generate interrupt at end of transfer)
+ * bit 2 - start bit (set to start transfer)
+ * bit 3 - direction (0 = DMA_TO_DEVICE, 1 = DMA_FROM_DEVICE
+ * bit 4:31 - reserved */
+ B3D_REG_EC220_DMA_STS = 0x8008,
+};
+
+enum b3dfg_buffer_state {
+ B3DFG_BUFFER_POLLED = 0,
+ B3DFG_BUFFER_PENDING,
+ B3DFG_BUFFER_POPULATED,
+};
+
+struct b3dfg_buffer {
+ unsigned char *frame[B3DFG_FRAMES_PER_BUFFER];
+ struct list_head list;
+ u8 state;
+};
+
+struct b3dfg_dev {
+
+ /* no protection needed: all finalized at initialization time */
+ struct pci_dev *pdev;
+ struct cdev chardev;
+ struct device *dev;
+ void __iomem *regs;
+ unsigned int frame_size;
+
+ /*
+ * Protects buffer state, including buffer_queue, triplet_ready,
+ * cur_dma_frame_idx & cur_dma_frame_addr.
+ */
+ spinlock_t buffer_lock;
+ struct b3dfg_buffer *buffers;
+ struct list_head buffer_queue;
+
+ /* Last frame in triplet transferred (-1 if none). */
+ int cur_dma_frame_idx;
+
+ /* Current frame's address for DMA. */
+ dma_addr_t cur_dma_frame_addr;
+
+ /*
+ * Protects cstate_tstamp.
+ * Nests inside buffer_lock.
+ */
+ spinlock_t cstate_lock;
+ unsigned long cstate_tstamp;
+
+ /*
+ * Protects triplets_dropped.
+ * Nests inside buffers_lock.
+ */
+ spinlock_t triplets_dropped_lock;
+ unsigned int triplets_dropped;
+
+ wait_queue_head_t buffer_waitqueue;
+
+ unsigned int transmission_enabled:1;
+ unsigned int triplet_ready:1;
+};
+
+static u8 b3dfg_devices[B3DFG_MAX_DEVS];
+
+static struct class *b3dfg_class;
+static dev_t b3dfg_devt;
+
+static const struct pci_device_id b3dfg_ids[] __devinitdata = {
+ { PCI_DEVICE(0x0b3d, 0x0001) },
+ { },
+};
+
+MODULE_DEVICE_TABLE(pci, b3dfg_ids);
+
+/***** user-visible types *****/
+
+struct b3dfg_poll {
+ int buffer_idx;
+ unsigned int triplets_dropped;
+};
+
+struct b3dfg_wait {
+ int buffer_idx;
+ unsigned int timeout;
+ unsigned int triplets_dropped;
+};
+
+/**** register I/O ****/
+
+static u32 b3dfg_read32(struct b3dfg_dev *fgdev, u16 reg)
+{
+ return ioread32(fgdev->regs + reg);
+}
+
+static void b3dfg_write32(struct b3dfg_dev *fgdev, u16 reg, u32 value)
+{
+ iowrite32(value, fgdev->regs + reg);
+}
+
+/**** buffer management ****/
+
+/*
+ * Program EC220 for transfer of a specific frame.
+ * Called with buffer_lock held.
+ */
+static int setup_frame_transfer(struct b3dfg_dev *fgdev,
+ struct b3dfg_buffer *buf, int frame)
+{
+ unsigned char *frm_addr;
+ dma_addr_t frm_addr_dma;
+ unsigned int frm_size = fgdev->frame_size;
+
+ frm_addr = buf->frame[frame];
+ frm_addr_dma = pci_map_single(fgdev->pdev, frm_addr,
+ frm_size, PCI_DMA_FROMDEVICE);
+ if (pci_dma_mapping_error(fgdev->pdev, frm_addr_dma))
+ return -ENOMEM;
+
+ fgdev->cur_dma_frame_addr = frm_addr_dma;
+ fgdev->cur_dma_frame_idx = frame;
+
+ b3dfg_write32(fgdev, B3D_REG_EC220_DMA_ADDR,
+ cpu_to_le32(frm_addr_dma));
+ b3dfg_write32(fgdev, B3D_REG_EC220_TRF_SIZE,
+ cpu_to_le32(frm_size >> 2));
+ b3dfg_write32(fgdev, B3D_REG_EC220_DMA_STS, 0xf);
+
+ return 0;
+}
+
+/* Caller should hold buffer lock */
+static void dequeue_all_buffers(struct b3dfg_dev *fgdev)
+{
+ int i;
+ for (i = 0; i < b3dfg_nbuf; i++) {
+ struct b3dfg_buffer *buf = &fgdev->buffers[i];
+ buf->state = B3DFG_BUFFER_POLLED;
+ list_del_init(&buf->list);
+ }
+}
+
+/* queue a buffer to receive data */
+static int queue_buffer(struct b3dfg_dev *fgdev, int bufidx)
+{
+ struct device *dev = &fgdev->pdev->dev;
+ struct b3dfg_buffer *buf;
+ unsigned long flags;
+ int r = 0;
+
+ spin_lock_irqsave(&fgdev->buffer_lock, flags);
+ if (bufidx < 0 || bufidx >= b3dfg_nbuf) {
+ dev_dbg(dev, "Invalid buffer index, %d\n", bufidx);
+ r = -ENOENT;
+ goto out;
+ }
+ buf = &fgdev->buffers[bufidx];
+
+ if (unlikely(buf->state == B3DFG_BUFFER_PENDING)) {
+ dev_dbg(dev, "buffer %d is already queued\n", bufidx);
+ r = -EINVAL;
+ goto out;
+ }
+
+ buf->state = B3DFG_BUFFER_PENDING;
+ list_add_tail(&buf->list, &fgdev->buffer_queue);
+
+ if (fgdev->transmission_enabled && fgdev->triplet_ready) {
+ dev_dbg(dev, "triplet is ready, pushing immediately\n");
+ fgdev->triplet_ready = 0;
+ r = setup_frame_transfer(fgdev, buf, 0);
+ if (r)
+ dev_err(dev, "unable to map DMA buffer\n");
+ }
+
+out:
+ spin_unlock_irqrestore(&fgdev->buffer_lock, flags);
+ return r;
+}
+
+/* non-blocking buffer poll. returns 1 if data is present in the buffer,
+ * 0 otherwise */
+static int poll_buffer(struct b3dfg_dev *fgdev, void __user *arg)
+{
+ struct device *dev = &fgdev->pdev->dev;
+ struct b3dfg_poll p;
+ struct b3dfg_buffer *buf;
+ unsigned long flags;
+ int r = 1;
+ int arg_out = 0;
+
+ if (copy_from_user(&p, arg, sizeof(p)))
+ return -EFAULT;
+
+ if (unlikely(!fgdev->transmission_enabled)) {
+ dev_dbg(dev, "cannot poll, transmission disabled\n");
+ return -EINVAL;
+ }
+
+ if (p.buffer_idx < 0 || p.buffer_idx >= b3dfg_nbuf)
+ return -ENOENT;
+
+ buf = &fgdev->buffers[p.buffer_idx];
+
+ spin_lock_irqsave(&fgdev->buffer_lock, flags);
+
+ if (likely(buf->state == B3DFG_BUFFER_POPULATED)) {
+ arg_out = 1;
+ buf->state = B3DFG_BUFFER_POLLED;
+
+ /* IRQs already disabled by spin_lock_irqsave above. */
+ spin_lock(&fgdev->triplets_dropped_lock);
+ p.triplets_dropped = fgdev->triplets_dropped;
+ fgdev->triplets_dropped = 0;
+ spin_unlock(&fgdev->triplets_dropped_lock);
+ } else {
+ r = 0;
+ }
+
+ spin_unlock_irqrestore(&fgdev->buffer_lock, flags);
+
+ if (arg_out && copy_to_user(arg, &p, sizeof(p)))
+ r = -EFAULT;
+
+ return r;
+}
+
+static unsigned long get_cstate_change(struct b3dfg_dev *fgdev)
+{
+ unsigned long flags, when;
+
+ spin_lock_irqsave(&fgdev->cstate_lock, flags);
+ when = fgdev->cstate_tstamp;
+ spin_unlock_irqrestore(&fgdev->cstate_lock, flags);
+ return when;
+}
+
+static int is_event_ready(struct b3dfg_dev *fgdev, struct b3dfg_buffer *buf,
+ unsigned long when)
+{
+ int result;
+ unsigned long flags;
+
+ spin_lock_irqsave(&fgdev->buffer_lock, flags);
+ spin_lock(&fgdev->cstate_lock);
+ result = (!fgdev->transmission_enabled ||
+ buf->state == B3DFG_BUFFER_POPULATED ||
+ when != fgdev->cstate_tstamp);
+ spin_unlock(&fgdev->cstate_lock);
+ spin_unlock_irqrestore(&fgdev->buffer_lock, flags);
+
+ return result;
+}
+
+/* sleep until a specific buffer becomes populated */
+static int wait_buffer(struct b3dfg_dev *fgdev, void __user *arg)
+{
+ struct device *dev = &fgdev->pdev->dev;
+ struct b3dfg_wait w;
+ struct b3dfg_buffer *buf;
+ unsigned long flags, when;
+ int r;
+
+ if (copy_from_user(&w, arg, sizeof(w)))
+ return -EFAULT;
+
+ if (!fgdev->transmission_enabled) {
+ dev_dbg(dev, "cannot wait, transmission disabled\n");
+ return -EINVAL;
+ }
+
+ if (w.buffer_idx < 0 || w.buffer_idx >= b3dfg_nbuf)
+ return -ENOENT;
+
+ buf = &fgdev->buffers[w.buffer_idx];
+
+ spin_lock_irqsave(&fgdev->buffer_lock, flags);
+
+ if (buf->state == B3DFG_BUFFER_POPULATED) {
+ r = w.timeout;
+ goto out_triplets_dropped;
+ }
+
+ spin_unlock_irqrestore(&fgdev->buffer_lock, flags);
+
+ when = get_cstate_change(fgdev);
+ if (w.timeout > 0) {
+ r = wait_event_interruptible_timeout(fgdev->buffer_waitqueue,
+ is_event_ready(fgdev, buf, when),
+ (w.timeout * HZ) / 1000);
+
+ if (unlikely(r < 0))
+ goto out;
+
+ w.timeout = r * 1000 / HZ;
+ } else {
+ r = wait_event_interruptible(fgdev->buffer_waitqueue,
+ is_event_ready(fgdev, buf, when));
+
+ if (unlikely(r)) {
+ r = -ERESTARTSYS;
+ goto out;
+ }
+ }
+
+ /* TODO: Inform the user via field(s) in w? */
+ if (!fgdev->transmission_enabled || when != get_cstate_change(fgdev)) {
+ r = -EINVAL;
+ goto out;
+ }
+
+ spin_lock_irqsave(&fgdev->buffer_lock, flags);
+
+ if (buf->state != B3DFG_BUFFER_POPULATED) {
+ r = -ETIMEDOUT;
+ goto out_unlock;
+ }
+
+ buf->state = B3DFG_BUFFER_POLLED;
+
+out_triplets_dropped:
+
+ /* IRQs already disabled by spin_lock_irqsave above. */
+ spin_lock(&fgdev->triplets_dropped_lock);
+ w.triplets_dropped = fgdev->triplets_dropped;
+ fgdev->triplets_dropped = 0;
+ spin_unlock(&fgdev->triplets_dropped_lock);
+
+out_unlock:
+ spin_unlock_irqrestore(&fgdev->buffer_lock, flags);
+ if (copy_to_user(arg, &w, sizeof(w)))
+ r = -EFAULT;
+out:
+ return r;
+}
+
+/* mmap page fault handler */
+static int b3dfg_vma_fault(struct vm_area_struct *vma,
+ struct vm_fault *vmf)
+{
+ struct b3dfg_dev *fgdev = vma->vm_file->private_data;
+ unsigned long off = vmf->pgoff << PAGE_SHIFT;
+ unsigned int frame_size = fgdev->frame_size;
+ unsigned int buf_size = frame_size * B3DFG_FRAMES_PER_BUFFER;
+ unsigned char *addr;
+
+ /* determine which buffer the offset lies within */
+ unsigned int buf_idx = off / buf_size;
+ /* and the offset into the buffer */
+ unsigned int buf_off = off % buf_size;
+
+ /* determine which frame inside the buffer the offset lies in */
+ unsigned int frm_idx = buf_off / frame_size;
+ /* and the offset into the frame */
+ unsigned int frm_off = buf_off % frame_size;
+
+ if (unlikely(buf_idx >= b3dfg_nbuf))
+ return VM_FAULT_SIGBUS;
+
+ addr = fgdev->buffers[buf_idx].frame[frm_idx] + frm_off;
+ vm_insert_pfn(vma, (unsigned long)vmf->virtual_address,
+ virt_to_phys(addr) >> PAGE_SHIFT);
+
+ return VM_FAULT_NOPAGE;
+}
+
+static struct vm_operations_struct b3dfg_vm_ops = {
+ .fault = b3dfg_vma_fault,
+};
+
+static int get_wand_status(struct b3dfg_dev *fgdev, int __user *arg)
+{
+ u32 wndstat = b3dfg_read32(fgdev, B3D_REG_WAND_STS);
+ dev_dbg(&fgdev->pdev->dev, "wand status %x\n", wndstat);
+ return __put_user(wndstat & 0x1, arg);
+}
+
+static int enable_transmission(struct b3dfg_dev *fgdev)
+{
+ u16 command;
+ unsigned long flags;
+ struct device *dev = &fgdev->pdev->dev;
+
+ dev_dbg(dev, "enable transmission\n");
+
+ /* check the cable is plugged in. */
+ if (!b3dfg_read32(fgdev, B3D_REG_WAND_STS)) {
+ dev_dbg(dev, "cannot start transmission without wand\n");
+ return -EINVAL;
+ }
+
+ /*
+ * Check we're a bus master.
+ * TODO: I think we can remove this having added the pci_set_master call
+ */
+ pci_read_config_word(fgdev->pdev, PCI_COMMAND, &command);
+ if (!(command & PCI_COMMAND_MASTER)) {
+ dev_err(dev, "not a bus master, force-enabling\n");
+ pci_write_config_word(fgdev->pdev, PCI_COMMAND,
+ command | PCI_COMMAND_MASTER);
+ }
+
+ spin_lock_irqsave(&fgdev->buffer_lock, flags);
+
+ /* Handle racing enable_transmission calls. */
+ if (fgdev->transmission_enabled) {
+ spin_unlock_irqrestore(&fgdev->buffer_lock, flags);
+ goto out;
+ }
+
+ spin_lock(&fgdev->triplets_dropped_lock);
+ fgdev->triplets_dropped = 0;
+ spin_unlock(&fgdev->triplets_dropped_lock);
+
+ fgdev->triplet_ready = 0;
+ fgdev->cur_dma_frame_idx = -1;
+ fgdev->transmission_enabled = 1;
+
+ spin_unlock_irqrestore(&fgdev->buffer_lock, flags);
+
+ /* Enable DMA and cable status interrupts. */
+ b3dfg_write32(fgdev, B3D_REG_HW_CTRL, 0x03);
+
+out:
+ return 0;
+}
+
+static void disable_transmission(struct b3dfg_dev *fgdev)
+{
+ struct device *dev = &fgdev->pdev->dev;
+ unsigned long flags;
+ u32 tmp;
+
+ dev_dbg(dev, "disable transmission\n");
+
+ /* guarantee that no more interrupts will be serviced */
+ spin_lock_irqsave(&fgdev->buffer_lock, flags);
+ fgdev->transmission_enabled = 0;
+
+ b3dfg_write32(fgdev, B3D_REG_HW_CTRL, 0);
+
+ /* FIXME: temporary debugging only. if the board stops transmitting,
+ * hitting ctrl+c and seeing this message is useful for determining
+ * the state of the board. */
+ tmp = b3dfg_read32(fgdev, B3D_REG_DMA_STS);
+ dev_dbg(dev, "DMA_STS reads %x after TX stopped\n", tmp);
+
+ dequeue_all_buffers(fgdev);
+ spin_unlock_irqrestore(&fgdev->buffer_lock, flags);
+
+ wake_up_interruptible(&fgdev->buffer_waitqueue);
+}
+
+static int set_transmission(struct b3dfg_dev *fgdev, int enabled)
+{
+ int res = 0;
+
+ if (enabled && !fgdev->transmission_enabled)
+ res = enable_transmission(fgdev);
+ else if (!enabled && fgdev->transmission_enabled)
+ disable_transmission(fgdev);
+
+ return res;
+}
+
+/* Called in interrupt context. */
+static void handle_cstate_unplug(struct b3dfg_dev *fgdev)
+{
+ /* Disable all interrupts. */
+ b3dfg_write32(fgdev, B3D_REG_HW_CTRL, 0);
+
+ /* Stop transmission. */
+ spin_lock(&fgdev->buffer_lock);
+ fgdev->transmission_enabled = 0;
+
+ fgdev->cur_dma_frame_idx = -1;
+ fgdev->triplet_ready = 0;
+ if (fgdev->cur_dma_frame_addr) {
+ pci_unmap_single(fgdev->pdev, fgdev->cur_dma_frame_addr,
+ fgdev->frame_size, PCI_DMA_FROMDEVICE);
+ fgdev->cur_dma_frame_addr = 0;
+ }
+ dequeue_all_buffers(fgdev);
+ spin_unlock(&fgdev->buffer_lock);
+}
+
+/* Called in interrupt context. */
+static void handle_cstate_change(struct b3dfg_dev *fgdev)
+{
+ u32 cstate = b3dfg_read32(fgdev, B3D_REG_WAND_STS);
+ unsigned long when;
+ struct device *dev = &fgdev->pdev->dev;
+
+ dev_dbg(dev, "cable state change: %u\n", cstate);
+
+ /*
+ * When the wand is unplugged we reset our state. The hardware will
+ * have done the same internally.
+ *
+ * Note we should never see a cable *plugged* event, as interrupts
+ * should only be enabled when transmitting, which requires the cable
+ * to be plugged. If we do see one it probably means the cable has been
+ * unplugged and re-plugged very rapidly. Possibly because it has a
+ * broken wire and is momentarily losing contact.
+ *
+ * TODO: At the moment if you plug in the cable then enable transmission
+ * the hardware will raise a couple of spurious interrupts, so
+ * just ignore them for now.
+ *
+ * Once the hardware is fixed we should complain and treat it as an
+ * unplug. Or at least track how frequently it is happening and do
+ * so if too many come in.
+ */
+ if (cstate) {
+ dev_warn(dev, "ignoring unexpected plug event\n");
+ return;
+ }
+ handle_cstate_unplug(fgdev);
+
+ /*
+ * Record cable state change timestamp & wake anyone waiting
+ * on a cable state change. Be paranoid about ensuring events
+ * are not missed if we somehow get two interrupts in a jiffy.
+ */
+ spin_lock(&fgdev->cstate_lock);
+ when = jiffies_64;
+ if (when <= fgdev->cstate_tstamp)
+ when = fgdev->cstate_tstamp + 1;
+ fgdev->cstate_tstamp = when;
+ wake_up_interruptible(&fgdev->buffer_waitqueue);
+ spin_unlock(&fgdev->cstate_lock);
+}
+
+/* Called with buffer_lock held. */
+static void transfer_complete(struct b3dfg_dev *fgdev)
+{
+ struct b3dfg_buffer *buf;
+ struct device *dev = &fgdev->pdev->dev;
+
+ pci_unmap_single(fgdev->pdev, fgdev->cur_dma_frame_addr,
+ fgdev->frame_size, PCI_DMA_FROMDEVICE);
+ fgdev->cur_dma_frame_addr = 0;
+
+ buf = list_entry(fgdev->buffer_queue.next, struct b3dfg_buffer, list);
+ if (buf) {
+ dev_dbg(dev, "handle frame completion\n");
+ if (fgdev->cur_dma_frame_idx == B3DFG_FRAMES_PER_BUFFER - 1) {
+
+ /* last frame of that triplet completed */
+ dev_dbg(dev, "triplet completed\n");
+ buf->state = B3DFG_BUFFER_POPULATED;
+ list_del_init(&buf->list);
+ wake_up_interruptible(&fgdev->buffer_waitqueue);
+ }
+ } else {
+ dev_err(dev, "got frame but no buffer!\n");
+ }
+}
+
+/*
+ * Called with buffer_lock held.
+ *
+ * Note that idx is the (1-based) *next* frame to be transferred, while
+ * cur_dma_frame_idx is the (0-based) *last* frame to have been transferred (or
+ * -1 if none). Thus there should be a difference of 2 between them.
+ */
+static bool setup_next_frame_transfer(struct b3dfg_dev *fgdev, int idx)
+{
+ struct b3dfg_buffer *buf;
+ struct device *dev = &fgdev->pdev->dev;
+ bool need_ack = 1;
+
+ dev_dbg(dev, "program DMA transfer for next frame: %d\n", idx);
+
+ buf = list_entry(fgdev->buffer_queue.next, struct b3dfg_buffer, list);
+ if (buf) {
+ if (idx == fgdev->cur_dma_frame_idx + 2) {
+ if (setup_frame_transfer(fgdev, buf, idx - 1))
+ dev_err(dev, "unable to map DMA buffer\n");
+ need_ack = 0;
+ } else {
+ dev_err(dev, "frame mismatch, got %d, expected %d\n",
+ idx, fgdev->cur_dma_frame_idx + 2);
+
+ /* FIXME: handle dropped triplets here */
+ }
+ } else {
+ dev_err(dev, "cannot setup DMA, no buffer\n");
+ }
+
+ return need_ack;
+}
+
+static irqreturn_t b3dfg_intr(int irq, void *dev_id)
+{
+ struct b3dfg_dev *fgdev = dev_id;
+ struct device *dev = &fgdev->pdev->dev;
+ u32 sts;
+ u8 dropped;
+ bool need_ack = 1;
+ irqreturn_t res = IRQ_HANDLED;
+
+ sts = b3dfg_read32(fgdev, B3D_REG_DMA_STS);
+ if (unlikely(sts == 0)) {
+ dev_warn(dev, "ignore interrupt, DMA status is 0\n");
+ res = IRQ_NONE;
+ goto out;
+ }
+
+ if (unlikely(!fgdev->transmission_enabled)) {
+ dev_warn(dev, "ignore interrupt, TX disabled\n");
+ res = IRQ_HANDLED;
+ goto out;
+ }
+
+ /* Handle dropped frames, as reported by the hardware. */
+ dropped = (sts >> 8) & 0xff;
+ dev_dbg(dev, "intr: DMA_STS=%08x (drop=%d comp=%d next=%d)\n",
+ sts, dropped, !!(sts & 0x4), sts & 0x3);
+ if (unlikely(dropped > 0)) {
+ spin_lock(&fgdev->triplets_dropped_lock);
+ fgdev->triplets_dropped += dropped;
+ spin_unlock(&fgdev->triplets_dropped_lock);
+ }
+
+ /* Handle a cable state change (i.e. the wand being unplugged). */
+ if (sts & 0x08) {
+ handle_cstate_change(fgdev);
+ goto out;
+ }
+
+ spin_lock(&fgdev->buffer_lock);
+ if (unlikely(list_empty(&fgdev->buffer_queue))) {
+
+ /* FIXME need more sanity checking here */
+ dev_info(dev, "buffer not ready for next transfer\n");
+ fgdev->triplet_ready = 1;
+ goto out_unlock;
+ }
+
+ /* Has a frame transfer been completed? */
+ if (sts & 0x4) {
+ u32 dma_status = b3dfg_read32(fgdev, B3D_REG_EC220_DMA_STS);
+
+ /* Check for DMA errors reported by the hardware. */
+ if (unlikely(dma_status & 0x1)) {
+ dev_err(dev, "EC220 error: %08x\n", dma_status);
+
+ /* FIXME flesh out error handling */
+ goto out_unlock;
+ }
+
+ /* Sanity check, we should have a frame index at this point. */
+ if (unlikely(fgdev->cur_dma_frame_idx == -1)) {
+ dev_err(dev, "completed but no last idx?\n");
+
+ /* FIXME flesh out error handling */
+ goto out_unlock;
+ }
+
+ transfer_complete(fgdev);
+ }
+
+ /* Is there another frame transfer pending? */
+ if (sts & 0x3)
+ need_ack = setup_next_frame_transfer(fgdev, sts & 0x3);
+ else
+ fgdev->cur_dma_frame_idx = -1;
+
+out_unlock:
+ spin_unlock(&fgdev->buffer_lock);
+out:
+ if (need_ack) {
+ dev_dbg(dev, "acknowledging interrupt\n");
+ b3dfg_write32(fgdev, B3D_REG_EC220_DMA_STS, 0x0b);
+ }
+ return res;
+}
+
+static int b3dfg_open(struct inode *inode, struct file *filp)
+{
+ struct b3dfg_dev *fgdev =
+ container_of(inode->i_cdev, struct b3dfg_dev, chardev);
+
+ dev_dbg(&fgdev->pdev->dev, "open\n");
+ filp->private_data = fgdev;
+ return 0;
+}
+
+static int b3dfg_release(struct inode *inode, struct file *filp)
+{
+ struct b3dfg_dev *fgdev = filp->private_data;
+ dev_dbg(&fgdev->pdev->dev, "release\n");
+ disable_transmission(fgdev);
+ return 0;
+}
+
+static long b3dfg_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+ struct b3dfg_dev *fgdev = filp->private_data;
+
+ switch (cmd) {
+ case B3DFG_IOCGFRMSZ:
+ return __put_user(fgdev->frame_size, (int __user *) arg);
+ case B3DFG_IOCGWANDSTAT:
+ return get_wand_status(fgdev, (int __user *) arg);
+ case B3DFG_IOCTTRANS:
+ return set_transmission(fgdev, (int) arg);
+ case B3DFG_IOCTQUEUEBUF:
+ return queue_buffer(fgdev, (int) arg);
+ case B3DFG_IOCTPOLLBUF:
+ return poll_buffer(fgdev, (void __user *) arg);
+ case B3DFG_IOCTWAITBUF:
+ return wait_buffer(fgdev, (void __user *) arg);
+ default:
+ dev_dbg(&fgdev->pdev->dev, "unrecognised ioctl %x\n", cmd);
+ return -EINVAL;
+ }
+}
+
+static unsigned int b3dfg_poll(struct file *filp, poll_table *poll_table)
+{
+ struct b3dfg_dev *fgdev = filp->private_data;
+ unsigned long flags, when;
+ int i;
+ int r = 0;
+
+ when = get_cstate_change(fgdev);
+ poll_wait(filp, &fgdev->buffer_waitqueue, poll_table);
+
+ spin_lock_irqsave(&fgdev->buffer_lock, flags);
+ for (i = 0; i < b3dfg_nbuf; i++) {
+ if (fgdev->buffers[i].state == B3DFG_BUFFER_POPULATED) {
+ r = POLLIN | POLLRDNORM;
+ break;
+ }
+ }
+ spin_unlock_irqrestore(&fgdev->buffer_lock, flags);
+
+ /* TODO: Confirm this is how we want to communicate the change. */
+ if (!fgdev->transmission_enabled || when != get_cstate_change(fgdev))
+ r = POLLERR;
+
+ return r;
+}
+
+static int b3dfg_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+ struct b3dfg_dev *fgdev = filp->private_data;
+ unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
+ unsigned long vsize = vma->vm_end - vma->vm_start;
+ unsigned long bufdatalen = b3dfg_nbuf * fgdev->frame_size * 3;
+ unsigned long psize = bufdatalen - offset;
+ int r = 0;
+
+ if (vsize <= psize) {
+ vma->vm_flags |= VM_IO | VM_RESERVED | VM_CAN_NONLINEAR |
+ VM_PFNMAP;
+ vma->vm_ops = &b3dfg_vm_ops;
+ } else {
+ r = -EINVAL;
+ }
+
+ return r;
+}
+
+static struct file_operations b3dfg_fops = {
+ .owner = THIS_MODULE,
+ .open = b3dfg_open,
+ .release = b3dfg_release,
+ .unlocked_ioctl = b3dfg_ioctl,
+ .poll = b3dfg_poll,
+ .mmap = b3dfg_mmap,
+};
+
+static void free_all_frame_buffers(struct b3dfg_dev *fgdev)
+{
+ int i, j;
+ for (i = 0; i < b3dfg_nbuf; i++)
+ for (j = 0; j < B3DFG_FRAMES_PER_BUFFER; j++)
+ kfree(fgdev->buffers[i].frame[j]);
+ kfree(fgdev->buffers);
+}
+
+/* initialize device and any data structures. called before any interrupts
+ * are enabled. */
+static int b3dfg_init_dev(struct b3dfg_dev *fgdev)
+{
+ int i, j;
+ u32 frm_size = b3dfg_read32(fgdev, B3D_REG_FRM_SIZE);
+
+ /* Disable interrupts. In abnormal circumstances (e.g. after a crash)
+ * the board may still be transmitting from the previous session. If we
+ * ensure that interrupts are disabled before we later enable them, we
+ * are sure to capture a triplet from the start, rather than starting
+ * from frame 2 or 3. Disabling interrupts causes the FG to throw away
+ * all buffered data and stop buffering more until interrupts are
+ * enabled again.
+ */
+ b3dfg_write32(fgdev, B3D_REG_HW_CTRL, 0);
+
+ fgdev->frame_size = frm_size * 4096;
+ fgdev->buffers = kzalloc(sizeof(struct b3dfg_buffer) * b3dfg_nbuf,
+ GFP_KERNEL);
+ if (!fgdev->buffers)
+ goto err_no_buf;
+ for (i = 0; i < b3dfg_nbuf; i++) {
+ struct b3dfg_buffer *buf = &fgdev->buffers[i];
+ for (j = 0; j < B3DFG_FRAMES_PER_BUFFER; j++) {
+ buf->frame[j] = kmalloc(fgdev->frame_size, GFP_KERNEL);
+ if (!buf->frame[j])
+ goto err_no_mem;
+ }
+ INIT_LIST_HEAD(&buf->list);
+ }
+
+ INIT_LIST_HEAD(&fgdev->buffer_queue);
+ init_waitqueue_head(&fgdev->buffer_waitqueue);
+ spin_lock_init(&fgdev->buffer_lock);
+ spin_lock_init(&fgdev->cstate_lock);
+ spin_lock_init(&fgdev->triplets_dropped_lock);
+ return 0;
+
+err_no_mem:
+ free_all_frame_buffers(fgdev);
+err_no_buf:
+ return -ENOMEM;
+}
+
+/* find next free minor number, returns -1 if none are availabile */
+static int get_free_minor(void)
+{
+ int i;
+ for (i = 0; i < B3DFG_MAX_DEVS; i++) {
+ if (b3dfg_devices[i] == 0)
+ return i;
+ }
+ return -1;
+}
+
+static int __devinit b3dfg_probe(struct pci_dev *pdev,
+ const struct pci_device_id *id)
+{
+ struct b3dfg_dev *fgdev = kzalloc(sizeof(*fgdev), GFP_KERNEL);
+ int r = 0;
+ int minor = get_free_minor();
+ dev_t devno = MKDEV(MAJOR(b3dfg_devt), minor);
+ unsigned long res_len;
+ resource_size_t res_base;
+
+ if (fgdev == NULL)
+ return -ENOMEM;
+
+ if (minor < 0) {
+ dev_err(&pdev->dev, "too many devices found!\n");
+ r = -EIO;
+ goto err_free;
+ }
+
+ b3dfg_devices[minor] = 1;
+ dev_info(&pdev->dev, "probe device with IRQ %d\n", pdev->irq);
+
+ cdev_init(&fgdev->chardev, &b3dfg_fops);
+ fgdev->chardev.owner = THIS_MODULE;
+
+ r = cdev_add(&fgdev->chardev, devno, 1);
+ if (r) {
+ dev_err(&pdev->dev, "cannot add char device\n");
+ goto err_release_minor;
+ }
+
+ fgdev->dev = device_create(
+ b3dfg_class,
+ &pdev->dev,
+ devno,
+ dev_get_drvdata(&pdev->dev),
+ DRIVER_NAME "%d", minor);
+
+ if (IS_ERR(fgdev->dev)) {
+ dev_err(&pdev->dev, "cannot create device\n");
+ r = PTR_ERR(fgdev->dev);
+ goto err_del_cdev;
+ }
+
+ r = pci_enable_device(pdev);
+ if (r) {
+ dev_err(&pdev->dev, "cannot enable PCI device\n");
+ goto err_dev_unreg;
+ }
+
+ res_len = pci_resource_len(pdev, B3DFG_BAR_REGS);
+ if (res_len != B3DFG_REGS_LENGTH) {
+ dev_err(&pdev->dev, "invalid register resource size\n");
+ r = -EIO;
+ goto err_disable;
+ }
+
+ if (pci_resource_flags(pdev, B3DFG_BAR_REGS)
+ != (IORESOURCE_MEM | IORESOURCE_SIZEALIGN)) {
+ dev_err(&pdev->dev, "invalid resource flags\n");
+ r = -EIO;
+ goto err_disable;
+ }
+ r = pci_request_regions(pdev, DRIVER_NAME);
+ if (r) {
+ dev_err(&pdev->dev, "cannot obtain PCI resources\n");
+ goto err_disable;
+ }
+
+ pci_set_master(pdev);
+
+ r = pci_set_dma_mask(pdev, DMA_32BIT_MASK);
+ if (r) {
+ dev_err(&pdev->dev, "no usable DMA configuration\n");
+ goto err_free_res;
+ }
+
+ res_base = pci_resource_start(pdev, B3DFG_BAR_REGS);
+ fgdev->regs = ioremap_nocache(res_base, res_len);
+ if (!fgdev->regs) {
+ dev_err(&pdev->dev, "regs ioremap failed\n");
+ r = -EIO;
+ goto err_free_res;
+ }
+
+ fgdev->pdev = pdev;
+ pci_set_drvdata(pdev, fgdev);
+ r = b3dfg_init_dev(fgdev);
+ if (r < 0) {
+ dev_err(&pdev->dev, "failed to initalize device\n");
+ goto err_unmap;
+ }
+
+ r = request_irq(pdev->irq, b3dfg_intr, IRQF_SHARED, DRIVER_NAME, fgdev);
+ if (r) {
+ dev_err(&pdev->dev, "couldn't request irq %d\n", pdev->irq);
+ goto err_free_bufs;
+ }
+
+ return 0;
+
+err_free_bufs:
+ free_all_frame_buffers(fgdev);
+err_unmap:
+ iounmap(fgdev->regs);
+err_free_res:
+ pci_release_regions(pdev);
+err_disable:
+ pci_disable_device(pdev);
+err_dev_unreg:
+ device_destroy(b3dfg_class, devno);
+err_del_cdev:
+ cdev_del(&fgdev->chardev);
+err_release_minor:
+ b3dfg_devices[minor] = 0;
+err_free:
+ kfree(fgdev);
+ return r;
+}
+
+static void __devexit b3dfg_remove(struct pci_dev *pdev)
+{
+ struct b3dfg_dev *fgdev = pci_get_drvdata(pdev);
+ unsigned int minor = MINOR(fgdev->chardev.dev);
+
+ dev_dbg(&pdev->dev, "remove\n");
+
+ free_irq(pdev->irq, fgdev);
+ iounmap(fgdev->regs);
+ pci_release_regions(pdev);
+ pci_disable_device(pdev);
+ device_destroy(b3dfg_class, MKDEV(MAJOR(b3dfg_devt), minor));
+ cdev_del(&fgdev->chardev);
+ free_all_frame_buffers(fgdev);
+ kfree(fgdev);
+ b3dfg_devices[minor] = 0;
+}
+
+static struct pci_driver b3dfg_driver = {
+ .name = DRIVER_NAME,
+ .id_table = b3dfg_ids,
+ .probe = b3dfg_probe,
+ .remove = __devexit_p(b3dfg_remove),
+};
+
+static int __init b3dfg_module_init(void)
+{
+ int r;
+
+ if (b3dfg_nbuf < 2) {
+ printk(KERN_ERR DRIVER_NAME
+ ": buffer_count is out of range (must be >= 2)");
+ return -EINVAL;
+ }
+
+ printk(KERN_INFO DRIVER_NAME ": loaded\n");
+
+ b3dfg_class = class_create(THIS_MODULE, DRIVER_NAME);
+ if (IS_ERR(b3dfg_class))
+ return PTR_ERR(b3dfg_class);
+
+ r = alloc_chrdev_region(&b3dfg_devt, 0, B3DFG_MAX_DEVS, DRIVER_NAME);
+ if (r)
+ goto err1;
+
+ r = pci_register_driver(&b3dfg_driver);
+ if (r)
+ goto err2;
+
+ return r;
+
+err2:
+ unregister_chrdev_region(b3dfg_devt, B3DFG_MAX_DEVS);
+err1:
+ class_destroy(b3dfg_class);
+ return r;
+}
+
+static void __exit b3dfg_module_exit(void)
+{
+ printk(KERN_INFO DRIVER_NAME ": unloaded\n");
+ pci_unregister_driver(&b3dfg_driver);
+ unregister_chrdev_region(b3dfg_devt, B3DFG_MAX_DEVS);
+ class_destroy(b3dfg_class);
+}
+
+module_init(b3dfg_module_init);
+module_exit(b3dfg_module_exit);