When PERST# is asserted once, EP configuration will be initialized. If PERST# has been already deasserted, it isn't necessary to assert here. This checks whether PERST# is deasserted using PCL_PINMON register, and adds omit controlling PERST#. Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx> --- drivers/pci/controller/dwc/pcie-uniphier.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/pci/controller/dwc/pcie-uniphier.c b/drivers/pci/controller/dwc/pcie-uniphier.c index 8fd7bad..1ea4220 100644 --- a/drivers/pci/controller/dwc/pcie-uniphier.c +++ b/drivers/pci/controller/dwc/pcie-uniphier.c @@ -22,6 +22,9 @@ #include "pcie-designware.h" +#define PCL_PINMON 0x0028 +#define PCL_PINMON_PERST_OUT BIT(16) + #define PCL_PINCTRL0 0x002c #define PCL_PERST_PLDN_REGEN BIT(12) #define PCL_PERST_NOE_REGEN BIT(11) @@ -100,6 +103,11 @@ static void uniphier_pcie_init_rc(struct uniphier_pcie_priv *priv) val |= PCL_SYS_AUX_PWR_DET; writel(val, priv->base + PCL_APP_PM0); + /* return if PERST# is already deasserted */ + val = readl(priv->base + PCL_PINMON); + if (val & PCL_PINMON_PERST_OUT) + return; + /* assert PERST# */ val = readl(priv->base + PCL_PINCTRL0); val &= ~(PCL_PERST_NOE_REGVAL | PCL_PERST_OUT_REGVAL -- 2.7.4
