[U-Boot] [PATCH 8/8] dm: tegra: pci: Convert tegra boards to driver model for PCI
Stephen Warren
swarren at wwwdotorg.org
Wed Oct 21 22:46:12 CEST 2015
On 10/17/2015 11:50 AM, Simon Glass wrote:
> Adjust the Tegra PCI driver to support driver model and move all boards over
> at the same time. This can make use of some generic driver model code, such
> as the range decoding logic.
FYI, this patch has quite a few conflicts with my series to add Tegra210
support. See the git branch I mentioned earlier for a quick-n-dirty
resolution to the conflicts, and subsequent fixups.
> diff --git a/arch/arm/mach-tegra/Kconfig b/arch/arm/mach-tegra/Kconfig
> index a5b7e0d..aff4900 100644
> --- a/arch/arm/mach-tegra/Kconfig
> +++ b/arch/arm/mach-tegra/Kconfig
> @@ -12,6 +12,7 @@ config TEGRA_ARMV7_COMMON
> select DM_I2C
> select DM_SPI
> select DM_GPIO
> + select DM_PCI
I wonder if we shouldn't create the TEGRA_COMMON config variable now,
since many of the options are common to both TEGRA_ARMV7_COMMON and
TEGRA210. Perhaps also TEGRA_ARMV8_COMMON too, although currently
there's only support for a single ARMV8 Tegra chip in U-Boot.
> diff --git a/drivers/pci/pci_tegra.c b/drivers/pci/pci_tegra.c
> -#define DEBUG
I actually find the debug prints useful, but yes I suppose debug should
be turned off!
> -static int tegra_pcie_read_conf(struct pci_controller *hose, pci_dev_t bdf,
> - int where, u32 *value)
> +static int pci_tegra_read_config(struct udevice *bus, pci_dev_t bdf,
> + uint offset, ulong *valuep,
> + enum pci_size_t size)
> {
> - struct tegra_pcie *pcie = to_tegra_pcie(hose);
> - unsigned long address;
> + struct tegra_pcie *pcie = dev_get_priv(bus);
> + unsigned long address, value;
> int err;
>
> - err = tegra_pcie_conf_address(pcie, bdf, where, &address);
> + err = tegra_pcie_conf_address(pcie, bdf, offset, &address);
> if (err < 0) {
> - *value = 0xffffffff;
> - return 1;
> + value = 0xffffffff;
> + goto done;
> }
>
> - *value = readl(address);
> + value = readl(address);
This function used to be used only for dword-sized reads. Presumably in
that case, "where" was always dword-aligned. When used for
word/byte-sized reads, the wrappers to do that (e.g.
pci_hose_read_config_word_via_dword) used to force the address passed to
this function to be dword-aligned. Now that this function handles all
sizes of read, I think it needs to align the address itself, doesn't it;
i.e. pass "offset & ~3" to tegra_pcie_conf_address() or "address & ~3"
to readl()? Same for the write function below.
This seems to work in practice without generating any alignment faults
though; I'm not sure why. Perhaps I'm missing something, or we're just
getting lucky?
> +int pci_skip_dev(struct pci_controller *hose, pci_dev_t dev)
The diff might be slightly smaller/clearer if this function wasn't moved?
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