[U-Boot] [PATCH 05/18] dm: pci: Add support for PCI driver matching
Bin Meng
bmeng.cn at gmail.com
Wed Jul 22 08:05:42 CEST 2015
Hi Simon,
On Wed, Jul 22, 2015 at 6:00 AM, Simon Glass <sjg at chromium.org> wrote:
> Hi Bin,
>
> On 21 July 2015 at 10:12, Bin Meng <bmeng.cn at gmail.com> wrote:
>> Hi Simon,
>>
>> On Tue, Jul 7, 2015 at 6:47 AM, Simon Glass <sjg at chromium.org> wrote:
>>> At present all PCI devices must be present in the device tree in order to
>>> be used. Many or most PCI devices don't require any configuration other than
>>> that which is done automatically by U-Boot. It is inefficent to add a node
>>> with nothing but a compatible string in order to get a device working.
>>>
>>> Add a mechanism whereby PCI drivers can be declared along with the device
>>> parameters they support (vendor/device/class). When no suitable driver is
>>> found in the device tree the list of such devices is consulted to determine
>>> the correct driver. If this also fails, then a generic driver is used as
>>> before.
>>>
>>> The mechanism used is very similar to that provided by Linux and the header
>>> file defintions are copied from Linux 4.1.
>>>
>>> Signed-off-by: Simon Glass <sjg at chromium.org>
>>> ---
>>>
>>> drivers/pci/pci-uclass.c | 129 ++++++++++++++++++++++++++++++++++++++++++-----
>>> include/pci.h | 79 ++++++++++++++++++++++++++++-
>>> 2 files changed, 193 insertions(+), 15 deletions(-)
>>>
>>> diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c
>>> index 5b91fe3..41daa0d 100644
>>> --- a/drivers/pci/pci-uclass.c
>>> +++ b/drivers/pci/pci-uclass.c
>>> @@ -353,6 +353,101 @@ int dm_pci_hose_probe_bus(struct pci_controller *hose, pci_dev_t bdf)
>>> return sub_bus;
>>> }
>>>
>>> +/**
>>> + * pci_match_one_device - Tell if a PCI device structure has a matching
>>> + * PCI device id structure
>>> + * @id: single PCI device id structure to match
>>> + * @dev: the PCI device structure to match against
>>> + *
>>> + * Returns the matching pci_device_id structure or %NULL if there is no match.
>>> + */
>>> +static bool pci_match_one_id(const struct pci_device_id *id,
>>> + const struct pci_device_id *find)
>>> +{
>>> + if ((id->vendor == PCI_ANY_ID || id->vendor == find->vendor) &&
>>> + (id->device == PCI_ANY_ID || id->device == find->device) &&
>>> + (id->subvendor == PCI_ANY_ID || id->subvendor == find->subvendor) &&
>>> + (id->subdevice == PCI_ANY_ID || id->subdevice == find->subdevice) &&
>>> + !((id->class ^ find->class) & id->class_mask))
>>> + return true;
>>> +
>>> + return false;
>>> +}
>>> +
>>> +/**
>>> + * pci_find_and_bind_driver() - Find and bind the right PCI driver
>>> + *
>>> + * This only looks at certain fields in the descriptor.
>>> + */
>>> +static int pci_find_and_bind_driver(struct udevice *parent,
>>> + struct pci_device_id *find_id, int devfn,
>>> + struct udevice **devp)
>>> +{
>>> + struct pci_driver_entry *start, *entry;
>>> + const char *drv;
>>> + int n_ents;
>>> + int ret;
>>> + char name[30], *str;
>>> +
>>> + *devp = NULL;
>>> +
>>> + debug("%s: Searching for driver: vendor=%x, device=%x\n", __func__,
>>> + find_id->vendor, find_id->device);
>>> + start = ll_entry_start(struct pci_driver_entry, pci_driver_entry);
>>> + n_ents = ll_entry_count(struct pci_driver_entry, pci_driver_entry);
>>> + for (entry = start; entry != start + n_ents; entry++) {
>>> + const struct pci_device_id *id;
>>> + struct udevice *dev;
>>> + const struct driver *drv;
>>> +
>>> + for (id = entry->match;
>>> + id->vendor || id->subvendor || id->class_mask;
>>> + id++) {
>>> + if (!pci_match_one_id(id, find_id))
>>> + continue;
>>> +
>>> + drv = entry->driver;
>>> + /*
>>> + * We could pass the descriptor to the driver as
>>> + * platdata (instead of NULL) and allow its bind()
>>> + * method to return -ENOENT if it doesn't support this
>>> + * device. That way we could continue the search to
>>> + * find another driver. For now this doesn't seem
>>> + * necesssary, so just bind the first match.
>>> + */
>>> + ret = device_bind(parent, drv, drv->name, NULL, -1,
>>> + &dev);
>>> + if (ret)
>>> + goto error;
>>> + debug("%s: Match found: %s\n", __func__, drv->name);
>>> + dev->driver_data = find_id->driver_data;
>>> + *devp = dev;
>>> + return 0;
>>> + }
>>> + }
>>> +
>>> + /* Bind a generic driver so that the device can be used */
>>> + sprintf(name, "pci_%x:%x.%x", parent->seq, PCI_DEV(devfn),
>>> + PCI_FUNC(devfn));
>>> + str = strdup(name);
>>> + if (!str)
>>> + return -ENOMEM;
>>> + drv = (find_id->class >> 8) == PCI_CLASS_BRIDGE_PCI ? "pci_bridge_drv" :
>>> + "pci_generic_drv";
>>> + ret = device_bind_driver(parent, drv, str, devp);
>>> + if (ret) {
>>> + debug("%s: Failed to bind generic driver: %d", __func__, ret);
>>> + return ret;
>>> + }
>>> + debug("%s: No match found: bound generic driver instead\n", __func__);
>>> +
>>> + return 0;
>>> +
>>> +error:
>>> + debug("%s: No match found: error %d\n", __func__, ret);
>>> + return ret;
>>> +}
>>> +
>>> int pci_bind_bus_devices(struct udevice *bus)
>>> {
>>> ulong vendor, device;
>>> @@ -387,25 +482,33 @@ int pci_bind_bus_devices(struct udevice *bus)
>>> bus->seq, bus->name, PCI_DEV(devfn), PCI_FUNC(devfn));
>>> pci_bus_read_config(bus, devfn, PCI_DEVICE_ID, &device,
>>> PCI_SIZE_16);
>>> - pci_bus_read_config(bus, devfn, PCI_CLASS_DEVICE, &class,
>>> - PCI_SIZE_16);
>>> + pci_bus_read_config(bus, devfn, PCI_CLASS_REVISION, &class,
>>> + PCI_SIZE_32);
>>> + class >>= 8;
>>>
>>> /* Find this device in the device tree */
>>> ret = pci_bus_find_devfn(bus, devfn, &dev);
>>>
>>> + /* Search for a driver */
>>> +
>>> /* If nothing in the device tree, bind a generic device */
>>> if (ret == -ENODEV) {
>>> - char name[30], *str;
>>> - const char *drv;
>>> -
>>> - sprintf(name, "pci_%x:%x.%x", bus->seq,
>>> - PCI_DEV(devfn), PCI_FUNC(devfn));
>>> - str = strdup(name);
>>> - if (!str)
>>> - return -ENOMEM;
>>> - drv = class == PCI_CLASS_BRIDGE_PCI ?
>>> - "pci_bridge_drv" : "pci_generic_drv";
>>> - ret = device_bind_driver(bus, drv, str, &dev);
>>> + struct pci_device_id find_id;
>>> + ulong val;
>>> +
>>> + memset(&find_id, '\0', sizeof(find_id));
>>> + find_id.vendor = vendor;
>>> + find_id.device = device;
>>> + find_id.class = class;
>>> + if ((header_type & 0x7f) == PCI_HEADER_TYPE_NORMAL) {
>>> + pci_bus_read_config(bus, devfn,
>>> + PCI_SUBSYSTEM_VENDOR_ID,
>>> + &val, PCI_SIZE_32);
>>> + find_id.subvendor = val & 0xffff;
>>> + find_id.subdevice = val >> 16;
>>> + }
>>> + ret = pci_find_and_bind_driver(bus, &find_id, devfn,
>>> + &dev);
>>> }
>>> if (ret)
>>> return ret;
>>> diff --git a/include/pci.h b/include/pci.h
>>> index 3af511b..d21fa8b 100644
>>> --- a/include/pci.h
>>> +++ b/include/pci.h
>>> @@ -468,7 +468,10 @@ typedef int pci_dev_t;
>>> #define PCI_ANY_ID (~0)
>>>
>>> struct pci_device_id {
>>> - unsigned int vendor, device; /* Vendor and device ID or PCI_ANY_ID */
>>> + unsigned int vendor, device; /* Vendor and device ID or PCI_ANY_ID */
>>> + unsigned int subvendor, subdevice; /* Subsystem ID's or PCI_ANY_ID */
>>> + unsigned int class, class_mask; /* (class,subclass,prog-if) triplet */
>>> + unsigned long driver_data; /* Data private to the driver */
>>> };
>>
>> Can we create another structure for dm? There are lots of codes which
>> only defines vendor id and device id like below:
>>
>> static struct pci_device_id mmc_supported[] = {
>> { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_TCF_SDIO_0 },
>> { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_TCF_SDIO_1 },
>> };
>>
>> Although compiler does not generate any error or warning, it is confusing.
>
> I think the existing structure is for exactly this purpose, - I have
> just added a few new fields. Why do we want to change it? I also
> really want to use this name as it matches Linux.
>
I mean it creates confusion if existing codes are unchanged, which
makes me think it contains only a vendor id and a device id for each
structure, but actually it has more members which are omitted. I would
do:
static struct pci_device_id mmc_supported[] = {
{ .vendor = PCI_VENDOR_ID_INTEL, .device =
PCI_DEVICE_ID_INTEL_TCF_SDIO_0 },
{ .vendor = PCI_VENDOR_ID_INTEL, .device =
PCI_DEVICE_ID_INTEL_TCF_SDIO_1 },
And one more comment at the end.
>>
>>>
>>> struct pci_controller;
>>> @@ -1110,7 +1113,79 @@ struct dm_pci_emul_ops {
>>> int sandbox_pci_get_emul(struct udevice *bus, pci_dev_t find_devfn,
>>> struct udevice **emulp);
>>>
>>> -#endif
>>> +/**
>>> + * PCI_DEVICE - macro used to describe a specific pci device
>>> + * @vend: the 16 bit PCI Vendor ID
>>> + * @dev: the 16 bit PCI Device ID
>>> + *
>>> + * This macro is used to create a struct pci_device_id that matches a
>>> + * specific device. The subvendor and subdevice fields will be set to
>>> + * PCI_ANY_ID.
>>> + */
>>> +#define PCI_DEVICE(vend, dev) \
>>> + .vendor = (vend), .device = (dev), \
>>> + .subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID
>>> +
>>> +/**
>>> + * PCI_DEVICE_SUB - macro used to describe a specific pci device with subsystem
>>> + * @vend: the 16 bit PCI Vendor ID
>>> + * @dev: the 16 bit PCI Device ID
>>> + * @subvend: the 16 bit PCI Subvendor ID
>>> + * @subdev: the 16 bit PCI Subdevice ID
>>> + *
>>> + * This macro is used to create a struct pci_device_id that matches a
>>> + * specific device with subsystem information.
>>> + */
>>> +#define PCI_DEVICE_SUB(vend, dev, subvend, subdev) \
>>> + .vendor = (vend), .device = (dev), \
>>> + .subvendor = (subvend), .subdevice = (subdev)
>>> +
>>> +/**
>>> + * PCI_DEVICE_CLASS - macro used to describe a specific pci device class
>>> + * @dev_class: the class, subclass, prog-if triple for this device
>>> + * @dev_class_mask: the class mask for this device
>>> + *
>>> + * This macro is used to create a struct pci_device_id that matches a
>>> + * specific PCI class. The vendor, device, subvendor, and subdevice
>>> + * fields will be set to PCI_ANY_ID.
>>> + */
>>> +#define PCI_DEVICE_CLASS(dev_class, dev_class_mask) \
>>> + .class = (dev_class), .class_mask = (dev_class_mask), \
>>> + .vendor = PCI_ANY_ID, .device = PCI_ANY_ID, \
>>> + .subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID
>>> +
>>> +/**
>>> + * PCI_VDEVICE - macro used to describe a specific pci device in short form
>>> + * @vend: the vendor name
>>> + * @dev: the 16 bit PCI Device ID
>>> + *
>>> + * This macro is used to create a struct pci_device_id that matches a
>>> + * specific PCI device. The subvendor, and subdevice fields will be set
>>> + * to PCI_ANY_ID. The macro allows the next field to follow as the device
>>> + * private data.
>>> + */
>>> +
>>> +#define PCI_VDEVICE(vend, dev) \
>>> + .vendor = PCI_VENDOR_ID_##vend, .device = (dev), \
>>> + .subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID, 0, 0
>>> +
>>> +/**
>>> + * struct pci_driver_entry - Matches a driver to its pci_device_id list
>>> + * @driver: Driver to use
>>> + * @match: List of match records for this driver, terminated by {}
>>> + */
>>> +struct pci_driver_entry {
>>> + struct driver *driver;
>>> + const struct pci_device_id *match;
>>> +};
>>> +
>>> +#define U_BOOT_PCI_DEVICE(__name, __match) \
>>> + ll_entry_declare(struct pci_driver_entry, __name, pci_driver_entry) = {\
>>> + .driver = llsym(struct driver, __name, driver), \
>>> + .match = __match, \
>>> + }
>>> +
>>> +#endif /* CONFIG_DM_PCI */
>>>
>>> #endif /* __ASSEMBLY__ */
>>> #endif /* _PCI_H */
>>> --
>>
>> Do you have plan to address the issue that dm pci cannot be used in
>> the pre-reloc phase? Like we need pci uart as the U-Boot console.
>
Do you have plan to address the issue that dm pci cannot be used in
the pre-reloc phase? Like we need pci uart as the U-Boot console.
Regards,
Bin
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