Hi Bin,
On 10 August 2015 at 00:18, Bin Meng <bmeng...@gmail.com> wrote:
> Hi Simon,
>
> On Sat, Aug 8, 2015 at 10:26 PM, Simon Glass <s...@chromium.org> wrote:
>> These functions allow iteration through all PCI devices including bridges.
>> The children of each PCI bus are returned in turn. This can be useful for
>> configuring, checking or enumerating all the devices.
>>
>> Signed-off-by: Simon Glass <s...@chromium.org>
>> ---
>>
>> Changes in v2:
>> - Add a comment as to why we need to scan multiple PCI controllers
>>
>> drivers/pci/pci-uclass.c | 62
>> ++++++++++++++++++++++++++++++++++++++++++++++++
>> include/pci.h | 25 +++++++++++++++++++
>> 2 files changed, 87 insertions(+)
>>
>> diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c
>> index b79927e..2d5a0c1 100644
>> --- a/drivers/pci/pci-uclass.c
>> +++ b/drivers/pci/pci-uclass.c
>> @@ -775,6 +775,68 @@ static int pci_bridge_write_config(struct udevice *bus,
>> pci_dev_t bdf,
>> return pci_bus_write_config(hose->ctlr, bdf, offset, value, size);
>> }
>>
>> +static int skip_to_next_device(struct udevice *bus, struct udevice **devp)
>> +{
>> + struct udevice *dev;
>> + int ret = 0;
>> +
>> + /*
>> + * Scan through all the PCI controllers. On x86 there will only be
>> one
>> + * but that is not necessarily true on other hardware.
>> + */
>> + do {
>> + do {
>> + device_find_first_child(bus, &dev);
>> + if (dev) {
>> + *devp = dev;
>> + return 0;
>> + }
>> + } while (dev);
>
> There is no need to do a 'do..while' here.
I think I misunderstood your comment last time. Yes I think this can be removed.
>
>> + ret = uclass_next_device(&bus);
>> + if (ret)
>> + return ret;
>> + } while (bus);
>> +
>> + return 0;
>> +}
>> +
>> +int pci_find_next_device(struct udevice **devp)
>> +{
>> + struct udevice *child = *devp;
>> + struct udevice *bus = child->parent;
>> + int ret;
>> +
>> + /* First try all the siblings */
>> + *devp = NULL;
>> + while (child) {
>> + device_find_next_child(&child);
>> + if (child) {
>> + *devp = child;
>> + return 0;
>> + }
>> + }
>> +
>> + /* We ran out of siblings. Try the next bus */
>> + ret = uclass_next_device(&bus);
>> + if (ret)
>> + return ret;
>> +
>> + return bus ? skip_to_next_device(bus, devp) : 0;
>> +}
>> +
>> +int pci_find_first_device(struct udevice **devp)
>> +{
>> + struct udevice *bus;
>> + int ret;
>> +
>> + *devp = NULL;
>> + ret = uclass_first_device(UCLASS_PCI, &bus);
>> + if (ret)
>> + return ret;
>> +
>> + return skip_to_next_device(bus, devp);
>> +}
>> +
>> UCLASS_DRIVER(pci) = {
>> .id = UCLASS_PCI,
>> .name = "pci",
>> diff --git a/include/pci.h b/include/pci.h
>> index d1e2765..488ff44 100644
>> --- a/include/pci.h
>> +++ b/include/pci.h
>> @@ -910,6 +910,31 @@ int pci_bus_find_devfn(struct udevice *bus, pci_dev_t
>> find_devfn,
>> struct udevice **devp);
>>
>> /**
>> + * pci_find_first_device() - return the first available PCI device
>> + *
>> + * This function and pci_find_first_device() allow iteration through all
>> + * available PCI devices on all buses. Assuming there are any, this will
>> + * return the first one.
>> + *
>> + * @devp: Set to the first available device, or NULL if no more are
>> left
>> + * or we got an error
>> + * @return 0 if all is OK, -ve on error (e.g. a bus/bridge failed to probe)
>> + */
>> +int pci_find_first_device(struct udevice **devp);
>> +
>> +/**
>> + * pci_find_next_device() - return the next available PCI device
>> + *
>> + * Finds the next available PCI device after the one supplied, or sets @devp
>> + * to NULL if there are no more.
>> + *
>> + * @devp: On entry, the last device returned. Set to the next available
>> + * device, or NULL if no more are left or we got an error
>> + * @return 0 if all is OK, -ve on error (e.g. a bus/bridge failed to probe)
>> + */
>> +int pci_find_next_device(struct udevice **devp);
>> +
>> +/**
>> * pci_get_ff() - Returns a mask for the given access size
>> *
>> * @size: Access size
>> --
>
> Regards,
> Bin
Regards,
Simon
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