Messages in this thread |  | | From | Gábor Stefanik <> | Date | Wed, 13 Apr 2011 22:37:44 +0200 | Subject | Re: [RFC][PATCH V4] axi: add AXI bus driver |
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On Wed, Apr 13, 2011 at 9:39 PM, Rafał Miłecki <zajec5@gmail.com> wrote: > 2011/4/13 Greg KH <greg@kroah.com>: >>> diff --git a/drivers/axi/axi_pci_bridge.c b/drivers/axi/axi_pci_bridge.c >>> new file mode 100644 >>> index 0000000..17e882c >>> --- /dev/null >>> +++ b/drivers/axi/axi_pci_bridge.c >>> @@ -0,0 +1,33 @@ >>> +/* >>> + * AXI PCI bridge module >>> + * >>> + * Licensed under the GNU/GPL. See COPYING for details. >>> + */ >>> + >>> +#include "axi_private.h" >>> + >>> +#include <linux/axi/axi.h> >>> +#include <linux/pci.h> >>> + >>> +static DEFINE_PCI_DEVICE_TABLE(axi_pci_bridge_tbl) = { >>> + { PCI_DEVICE(PCI_VENDOR_ID_BROADCOM, 0x4331) }, >>> + { PCI_DEVICE(PCI_VENDOR_ID_BROADCOM, 0x4353) }, >>> + { PCI_DEVICE(PCI_VENDOR_ID_BROADCOM, 0x4727) }, >>> + { 0, }, >>> +}; >>> +MODULE_DEVICE_TABLE(pci, axi_pci_bridge_tbl); >>> + >>> +static struct pci_driver axi_pci_bridge_driver = { >>> + .name = "axi-pci-bridge", >>> + .id_table = axi_pci_bridge_tbl, >>> +}; >>> + >>> +int __init axi_pci_bridge_init(void) >>> +{ >>> + return axi_host_pci_register(&axi_pci_bridge_driver); >>> +} >>> + >>> +void __exit axi_pci_bridge_exit(void) >>> +{ >>> + axi_host_pci_unregister(&axi_pci_bridge_driver); >>> +} >> >> You register a pci driver that does nothing? That's not right, you need >> to then base your axi bus off of that pci device, so it is hooked up >> correctly in the /sys/devices/ tree. Otherwise you are somewhere up in >> the virtual location for your axi bus, right? > > Please take a look at: > driver->probe = axi_host_pci_probe; > driver->remove = axi_host_pci_remove; > return pci_register_driver(driver); > > >>> +bool axi_core_is_enabled(struct axi_device *core) >>> +{ >>> + if ((axi_aread32(core, AXI_IOCTL) & (AXI_IOCTL_CLK | AXI_IOCTL_FGC)) >>> + != AXI_IOCTL_CLK) >>> + return false; >>> + if (axi_aread32(core, AXI_RESET_CTL) & AXI_RESET_CTL_RESET) >>> + return false; >>> + return true; >>> +} >>> +EXPORT_SYMBOL(axi_core_is_enabled); >> >> EXPORT_SYMBOL_GPL()? >> >> What module uses this? And why would it care? >> >>> +EXPORT_SYMBOL(axi_core_enable); >> >> EXPORT_SYMBOL_GPL()? >> >> Same goes for your other exports, just want you to be sure here. > > Hm, I'm not sure. Using EXPORT_SYMBOL_GPL will forbid closed source > drivers from using our bus driver, right? I'm don't have preferences > on this, if you prefer us to force GPL, I can.
Isn't EXPORT_SYMBOL_GPL for symbols that are considered to form a tight coupling between the kernel and users of the symbol? Using _GPL just because you are against proprietary drivers in general and want to force GPL on HW vendors is wrong.
> > >>> +u32 xaxi_chipco_gpio_control(struct axi_drv_cc *cc, u32 mask, u32 value) >>> +{ >>> + return axi_cc_write32_masked(cc, AXI_CC_GPIOCTL, mask, value); >>> +} >>> +EXPORT_SYMBOL(xaxi_chipco_gpio_control); >> >> "xaxi"? Shouldn't that be consistant with the other exports and start >> with "axi"? > > Left from old tests/rewrites/splitting. Thanks. > > >>> +static u8 axi_host_pci_read8(struct axi_device *core, u16 offset) >>> +{ >>> + if (unlikely(core->bus->mapped_core != core)) >> >> Are you sure about the use of unlikely in this, and other functions? >> The compiler almost always does a better job than we do for these types >> of calls, just let it do it's job. >> >>> + axi_host_pci_switch_core(core); >>> + return ioread8(core->bus->mmio + offset); >> >> I think because of that unlikely, you just slowed down all pci devices, >> right? That's not very nice :) > > Hm, my logic suggests it is alright, but please consider this once > more with me ;) > > For the most of the time mapped_core (active core) do not change. We > perform few hundreds of operations on one core in a row. This way > mapped_core points to passed core for most of the time. Condition > (mapped_core != core) is unlikely to happen. > > Is there anything wrong in my logic? > > -- > Rafał > -- > To unsubscribe from this list: send the line "unsubscribe linux-wireless" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >
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