Re: PCI driver

Manu Abraham
2005-09-14T12:40:07Z

Jiri Slaby wrote:

> Manu Abraham napsal(a):
>
>> Jiri Slaby wrote:
>>
>>> Manu Abraham napsal(a):
>>>
>>>> Jiri Slaby wrote:
>>>>
>>>>> Manu Abraham napsal(a):
>>>>>
>>>>>> Now that i have been trying to implement the driver using the new
>>>>>> PCI API, i feel a bit lost at the different changes gone into the
>>>>>> PCI API. So if someone could give me a brief idea how a minimal
>>>>>> PCI probe routine should consist of, that would be quite helpful.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> Maybe, you want to read http://lwn.net/Kernel/LDD3/, chapter 12,
>>>>> pages 311+.
>>>>>
>>>>
>>>> I have been updating myself from LDD2 to LDD3. What i was wondering
>>>> was in what order should i be calling the functions.
>>>
>>>
>>>
>>>
>>> You won't call anything, kernel does. You only register driver.
>>> struct pcitbl {venids, devids}
>>>
>>> struct driver ... = {probe=a, remove=b, tbl=pcitbl};
>>> a() { if device from pcitbl is in the system (or has been added
>>> before some little time) this function is called}
>>> b() {if the device was removed from system: modules and hotplug:
>>> never called; modules: so if modules unload; if both: if the device
>>> was removed on the fly, or module unload}
>>>
>>> module_init() { register_driver(driver)}
>>> module_exit() { unregister_driver(driver); }
>>>
>>
>> I was wondering whether pci_enable_device() should come first or
>> pci_dev_put() in the probe routine.
>
> pci_dev_put? No, it counts down reference count, so you would loose
> the structure. You do NOT do pci_dev_put anymore with pci probing (but
> some very very specific cases).

Oh, i thought after a pci_dev_get() one does a pci_dev_put()
I wrote something like this, i was now confused with what to do with
pci_get_drvdata() and pci_set_drvdata()
I am not very sure whether i am doing it right in the first place, since
my mapped memory seems to be wrong, but first i have to clear up about
pci_get/set_drvdata().

Manu

static int mantis_pci_probe(*struct* pci_dev *pdev, const *struct* pci_device_id *mantis_pci_table)
{
*struct* mantis_pci *mantis;
u8 revision, latency;

pdev = pci_get_device(PCI_VENDOR_ID_MANTIS, PCI_DEVICE_ID_MANTIS_R11, NULL);
*if* (pdev) {
dprintk(verbose, MANTIS_DEBUG, 1, "Found a mantis chip");
*if* ((mantis = (*struct* mantis_pci *) kmalloc(*sizeof* (*struct* mantis_pci), GFP_KERNEL)) == NULL) {
dprintk(verbose, MANTIS_ERROR, 1, "Out of memory");
*return* -ENOMEM;
}
*if* (pci_enable_device(pdev) < 0) {
dprintk(verbose, MANTIS_ERROR, 1, "Could not enable device");
kfree(mantis);
*return* -ENODEV;
}
mantis->pdev = pdev;
mantis->mantis_addr = pci_resource_start(pdev, 0);
*if* (!request_mem_region(pci_resource_start(pdev, 0),
pci_resource_len(pdev, 0), DRIVER_NAME)) {
kfree(mantis);
*return* -EBUSY;
}
pci_read_config_byte(mantis->pdev, PCI_CLASS_REVISION, &revision);
pci_read_config_byte(mantis->pdev, PCI_LATENCY_TIMER, &latency);
mantis->mantis_mmio = ioremap(mantis->mantis_addr, 0x1000);
mmwrite(0, MANTIS_INT_STAT); //* Clear interrupts *//
*if* (request_irq(mantis->pdev->irq, (void *) mantis_pci_irq, SA_SHIRQ |
SA_INTERRUPT, DRIVER_NAME, (void *) mantis) < 0) {
dprintk(verbose, MANTIS_ERROR, 1, "Mantis IRQ registration failed");
release_mem_region(pci_resource_start(mantis->pdev, 0),
pci_resource_len(mantis->pdev, 0));
pci_disable_device(pdev);
kfree(mantis);
}
pci_dev_put(pdev);

}

*return* 0;
}