Hi Jiri,
On 3/7/07, Jiri Slaby <[EMAIL PROTECTED]> wrote:
add sensable phantom driver
...
General question - can this driver use force-feedback mecahnisms
already present in kernel instead of exporting raw datastream to
userspace. What are shortcomings of kernels force-feedback
implemenattion that make it insufficient for phantom?
+
+#define phantom_remap(io, vma, addr) ({ \
+ vma->vm_pgoff = (addr) >> PAGE_SHIFT; \
+ io ## remap_pfn_range(vma, (vma)->vm_start, (vma)->vm_pgoff, \
+ (vma)->vm_end - (vma)->vm_start, (vma)->vm_page_prot); \
+})
+
+static int phantom_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ struct phantom_device *dev = file->private_data;
+ int retval;
+
+ switch (vma->vm_pgoff) {
+ case 0:
+ retval = phantom_remap(, vma, virt_to_phys(dev->stat));
This really hurts my eyes. Is there any reason for using the macro here?
+ break;
+ case 1:
+ retval = phantom_remap(io_, vma, dev->ibase);
+ break;
+ default:
+ retval = phantom_remap(io_, vma, dev->obase);
+ }
+
+ return retval ? -EINVAL : 0;
+}
+
+
+static int __devinit phantom_probe(struct pci_dev *pdev,
+ const struct pci_device_id *pci_id)
+{
+ struct phantom_device *pht;
+ unsigned int minor;
+ int retval;
+
+ retval = pci_enable_device(pdev);
+ if (retval)
+ goto err;
+
+ minor = phantom_get_free();
+ if (minor == PHANTOM_MAX_MINORS) {
+ dev_err(&pdev->dev, "too many devices found!\n");
+ retval = -EIO;
+ goto err;
+ }
+
+ phantom_devices[minor] = 1;
Locking? In face of multithreaded PCI probes it might be needed.
+
+ retval = pci_request_regions(pdev, "phantom");
+ if (retval)
+ goto err_null;
+
+ retval = -ENOMEM;
+ pht = kzalloc(sizeof(*pht), GFP_KERNEL);
+ if (pht == NULL) {
+ dev_err(&pdev->dev, "unable to allocate device\n");
+ goto err_reg;
+ }
+
+ pht->stat = (void *)__get_free_page(GFP_KERNEL | __GFP_WAIT);
+ if (pht->stat == NULL)
+ goto err_fr;
+
+ pht->caddr = pci_iomap(pdev, 0, 0);
+ if (pht->caddr == NULL) {
+ dev_err(&pdev->dev, "can't remap conf space\n");
+ goto err_frp;
+ }
+ pht->ibase = pci_resource_start(pdev, 2);
+ pht->obase = pci_resource_start(pdev, 3);
+
+ mutex_init(&pht->open_lock);
+ init_waitqueue_head(&pht->wait);
+
+ phantom_write_cfgl(pht, 0, PHN_IRQCTL);
+ retval = request_irq(pdev->irq, phantom_isr,
+ IRQF_SHARED | IRQF_DISABLED, "phantom", pht);
+ if (retval) {
+ dev_err(&pdev->dev, "can't establish ISR\n");
+ goto err_unm;
+ }
+
+ cdev_init(&pht->cdev, &phantom_file_ops);
+ pht->cdev.owner = THIS_MODULE;
+ retval = cdev_add(&pht->cdev, MKDEV(phantom_major, minor), 1);
+ if (retval) {
+ dev_err(&pdev->dev, "chardev registration failed\n");
+ goto err_irq;
+ }
+
+ device_create(phantom_class, &pdev->dev, MKDEV(phantom_major, minor),
+ "phantom%u", minor);
+
Error handling is needed.
--
Dmitry
