From: Alyssa Rosenzweig <alyssa@xxxxxxxxxxxxx>
Apple's PCIe controller requires clocks to be configured in order to
bring up the hardware. Add the register pokes required to do so.
Adapted from Corellium's driver via Mark Kettenis's U-Boot patches.
Co-developed-by: Stan Skowronek <stan@xxxxxxxxxxxxx>
Signed-off-by: Stan Skowronek <stan@xxxxxxxxxxxxx>
Signed-off-by: Alyssa Rosenzweig <alyssa@xxxxxxxxxxxxx>
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
---
drivers/pci/controller/pcie-apple.c | 46 +++++++++++++++++++++++++++++
1 file changed, 46 insertions(+)
diff --git a/drivers/pci/controller/pcie-apple.c b/drivers/pci/controller/pcie-apple.c
index 2479a4168439..2620fd9d0ab1 100644
--- a/drivers/pci/controller/pcie-apple.c
+++ b/drivers/pci/controller/pcie-apple.c
@@ -132,6 +132,48 @@ static void rmw_set(u32 set, void __iomem *addr)
writel_relaxed(readl_relaxed(addr) | set, addr);
}
+static void rmw_clear(u32 clr, void __iomem *addr)
+{
+ writel_relaxed(readl_relaxed(addr) & ~clr, addr);
+}
+
+static int apple_pcie_setup_refclk(struct apple_pcie *pcie,
+ struct apple_pcie_port *port)
+{
+ u32 stat;
+ int res;
+
+ res = readl_relaxed_poll_timeout(pcie->base + CORE_RC_PHYIF_STAT, stat,
+ stat & CORE_RC_PHYIF_STAT_REFCLK,
+ 100, 50000);
+ if (res < 0)
+ return res;
+
+ rmw_set(CORE_LANE_CTL_CFGACC, pcie->base + CORE_LANE_CTL(port->idx));
+ rmw_set(CORE_LANE_CFG_REFCLK0REQ, pcie->base + CORE_LANE_CFG(port->idx));
+
+ res = readl_relaxed_poll_timeout(pcie->base + CORE_LANE_CFG(port->idx),
+ stat, stat & CORE_LANE_CFG_REFCLK0ACK,
+ 100, 50000);
+ if (res < 0)
+ return res;
+
+ rmw_set(CORE_LANE_CFG_REFCLK1, pcie->base + CORE_LANE_CFG(port->idx));
+ res = readl_relaxed_poll_timeout(pcie->base + CORE_LANE_CFG(port->idx),
+ stat, stat & CORE_LANE_CFG_REFCLK1,
+ 100, 50000);
+
+ if (res < 0)
+ return res;
+
+ rmw_clear(CORE_LANE_CTL_CFGACC, pcie->base + CORE_LANE_CTL(port->idx));
+
+ rmw_set(CORE_LANE_CFG_REFCLKEN, pcie->base + CORE_LANE_CFG(port->idx));
+ rmw_set(PORT_REFCLK_EN, port->base + PORT_REFCLK);
+
+ return 0;
+}
+
static int apple_pcie_setup_port(struct apple_pcie *pcie,
struct device_node *np)
{
@@ -165,6 +207,10 @@ static int apple_pcie_setup_port(struct apple_pcie *pcie,
rmw_set(PORT_APPCLK_EN, port + PORT_APPCLK);
+ ret = apple_pcie_setup_refclk(pcie, port);
+ if (ret < 0)
+ return ret;
+
rmw_set(PORT_PERST_OFF, port->base + PORT_PERST);
gpiod_set_value(reset, 1);
--
2.30.2
