Messages in this thread | | | Date | Wed, 7 Mar 2007 09:47:08 -0500 | From | "Dmitry Torokhov" <> | Subject | Re: [PATCH 1/1] Input: add sensable phantom driver |
| |
Hi Jiri,
On 3/7/07, Jiri Slaby <jirislaby@gmail.com> 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 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |