[PATCH 2/3] [ARM] tegra: add PCI Express support

[ccross@google.com (Colin Cross)]

On Thu, Sep 16, 2010 at 9:53 AM, Mike Rapoport <mike@compulab.co.il> wrote:
> Signed-off-by: Mike Rapoport <mike@compulab.co.il>
> ---
> ?arch/arm/mach-tegra/Kconfig ? ? ? ? ? ? ? ? | ? ?4 +
> ?arch/arm/mach-tegra/Makefile ? ? ? ? ? ? ? ?| ? ?1 +
> ?arch/arm/mach-tegra/board.h ? ? ? ? ? ? ? ? | ? ?1 +
> ?arch/arm/mach-tegra/include/mach/hardware.h | ? ?4 +
> ?arch/arm/mach-tegra/pcie.c ? ? ? ? ? ? ? ? ?| ?889 +++++++++++++++++++++++++++
> ?5 files changed, 899 insertions(+), 0 deletions(-)
> ?create mode 100644 arch/arm/mach-tegra/pcie.c
>
<snip>

> +/* register definitions */
> +#define AFI_OFSET ? ? ?0x3800
> +#define PADS_OFSET ? ? 0x3000
OFFSET

> +#define RP0_OFFSET ? ? 0x0000
> +#define RP1_OFFSET ? ? 0x1000

<snip>

> +static void tegra_pcie_xclk_clamp(bool clamp)
> +{
> + ? ? ? u32 reg;
> +
> + ? ? ? reg = pmc_readl(PMC_SCRATCH42) & ~PMC_SCRATCH42_PCX_CLAMP;
> +
> + ? ? ? if (clamp)
> + ? ? ? ? ? ? ? reg |= PMC_SCRATCH42_PCX_CLAMP;
> +
> + ? ? ? pmc_writel(reg, PMC_SCRATCH42);
> +}

Maybe add this to mach-tegra/powergate.c, to avoid having to set PMC
registers directly?

> +static int tegra_pcie_power_on(void)
> +{
> + ? ? ? int err;
> +
> + ? ? ? tegra_pcie_xclk_clamp(true);
> + ? ? ? tegra_periph_reset_assert(tegra_pcie.pcie_xclk);
> + ? ? ? tegra_pcie_xclk_clamp(false);
> +
> + ? ? ? clk_enable(tegra_pcie.afi_clk);
> + ? ? ? clk_enable(tegra_pcie.pex_clk);
> + ? ? ? return clk_enable(tegra_pcie.pll_e);
> +}
Any reason you can't use the powergate api here too?

> +static void tegra_pcie_power_off(void)
> +{
> + ? ? ? tegra_periph_reset_assert(tegra_pcie.pcie_xclk);
> + ? ? ? tegra_periph_reset_assert(tegra_pcie.afi_clk);
> + ? ? ? tegra_periph_reset_assert(tegra_pcie.pex_clk);
> +
> + ? ? ? tegra_pcie_xclk_clamp(true);
> +}
Can you power off the pcie partition?