@@ -457,8 +457,10 @@ static int cdns_pcie_ep_start(struct pci_epc *epc)
{
struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
struct cdns_pcie *pcie = &ep->pcie;
+ struct device *dev = pcie->dev;
struct pci_epf *epf;
u32 cfg;
+ int ret;
/*
* BIT(0) is hardwired to 1, hence function 0 is always enabled
@@ -469,6 +471,12 @@ static int cdns_pcie_ep_start(struct pci_epc *epc)
cfg |= BIT(epf->func_no);
cdns_pcie_writel(pcie, CDNS_PCIE_LM_EP_FUNC_CFG, cfg);
+ ret = cdns_pcie_start_link(pcie);
+ if (ret) {
+ dev_err(dev, "Failed to start link\n");
+ return ret;
+ }
+
return 0;
}
@@ -3,6 +3,7 @@
// Cadence PCIe host controller driver.
// Author: Cyrille Pitchen <cyrille.pitchen@free-electrons.com>
+#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/of_address.h>
#include <linux/of_pci.h>
@@ -200,6 +201,23 @@ static int cdns_pcie_host_init(struct device *dev,
return err;
}
+static int cdns_pcie_host_wait_for_link(struct cdns_pcie *pcie)
+{
+ struct device *dev = pcie->dev;
+ int retries;
+
+ /* Check if the link is up or not */
+ for (retries = 0; retries < LINK_WAIT_MAX_RETRIES; retries++) {
+ if (cdns_pcie_link_up(pcie)) {
+ dev_info(dev, "Link up\n");
+ return 0;
+ }
+ usleep_range(LINK_WAIT_USLEEP_MIN, LINK_WAIT_USLEEP_MAX);
+ }
+
+ return -ETIMEDOUT;
+}
+
int cdns_pcie_host_setup(struct cdns_pcie_rc *rc)
{
struct device *dev = rc->pcie.dev;
@@ -253,6 +271,16 @@ int cdns_pcie_host_setup(struct cdns_pcie_rc *rc)
pcie->mem_res = res;
+ ret = cdns_pcie_start_link(pcie);
+ if (ret) {
+ dev_err(dev, "Failed to start link\n");
+ return ret;
+ }
+
+ ret = cdns_pcie_host_wait_for_link(pcie);
+ if (ret)
+ dev_dbg(dev, "PCIe link never came up\n");
+
ret = cdns_pcie_host_init(dev, &resources, rc);
if (ret)
return ret;
@@ -10,6 +10,11 @@
#include <linux/pci.h>
#include <linux/phy/phy.h>
+/* Parameters for the waiting for link up routine */
+#define LINK_WAIT_MAX_RETRIES 10
+#define LINK_WAIT_USLEEP_MIN 90000
+#define LINK_WAIT_USLEEP_MAX 100000
+
/*
* Local Management Registers
*/
@@ -227,6 +232,9 @@ enum cdns_pcie_msg_routing {
struct cdns_pcie_ops {
u32 (*read)(void __iomem *addr, int size);
void (*write)(void __iomem *addr, int size, u32 value);
+ int (*start_link)(struct cdns_pcie *pcie);
+ void (*stop_link)(struct cdns_pcie *pcie);
+ bool (*link_up)(struct cdns_pcie *pcie);
};
/**
@@ -457,6 +465,28 @@ static inline u32 cdns_pcie_ep_fn_readl(struct cdns_pcie *pcie, u8 fn, u32 reg)
return readl(addr);
}
+static inline int cdns_pcie_start_link(struct cdns_pcie *pcie)
+{
+ if (pcie->ops->start_link)
+ return pcie->ops->start_link(pcie);
+
+ return 0;
+}
+
+static inline void cdns_pcie_stop_link(struct cdns_pcie *pcie)
+{
+ if (pcie->ops->stop_link)
+ pcie->ops->stop_link(pcie);
+}
+
+static inline bool cdns_pcie_link_up(struct cdns_pcie *pcie)
+{
+ if (pcie->ops->link_up)
+ return pcie->ops->link_up(pcie);
+
+ return true;
+}
+
#ifdef CONFIG_PCIE_CADENCE_HOST
int cdns_pcie_host_setup(struct cdns_pcie_rc *rc);
#else
Add cdns_pcie_ops to start link and verify link status. The registers to start link and to check link status is in Platform specific PCIe wrapper. Add support for platform specific drivers to add callback functions for the PCIe Cadence core to start link and verify link status. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> --- .../pci/controller/cadence/pcie-cadence-ep.c | 8 +++++ .../controller/cadence/pcie-cadence-host.c | 28 +++++++++++++++++ drivers/pci/controller/cadence/pcie-cadence.h | 30 +++++++++++++++++++ 3 files changed, 66 insertions(+)