PCI: designware: Add generic dw_pcie_wait_for_link()
Several DesignWare-based drivers (dra7xx, exynos, imx6, keystone, qcom, and
spear13xx) had similar loops waiting for the link to come up.
Add a generic dw_pcie_wait_for_link() for use by all these drivers so the
waiting is done consistently, e.g., always using usleep_range() rather than
mdelay() and using similar timeouts and retry counts.
Note that this changes the Keystone link training/wait for link strategy,
so we initiate link training, then wait longer for the link to come up
before re-initiating link training.
[bhelgaas: changelog, split into its own patch, update pci-keystone.c, pcie-qcom.c]
Signed-off-by: Joao Pinto <jpinto@synopsys.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Pratyush Anand <pratyush.anand@gmail.com>
diff --git a/drivers/pci/host/pcie-designware.h b/drivers/pci/host/pcie-designware.h
index 2356d29..f437f9b 100644
--- a/drivers/pci/host/pcie-designware.h
+++ b/drivers/pci/host/pcie-designware.h
@@ -22,6 +22,11 @@
#define MAX_MSI_IRQS 32
#define MAX_MSI_CTRLS (MAX_MSI_IRQS / 32)
+/* 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
+
struct pcie_port {
struct device *dev;
u8 root_bus_nr;
@@ -76,6 +81,7 @@
int dw_pcie_cfg_write(void __iomem *addr, int size, u32 val);
irqreturn_t dw_handle_msi_irq(struct pcie_port *pp);
void dw_pcie_msi_init(struct pcie_port *pp);
+int dw_pcie_wait_for_link(struct pcie_port *pp);
int dw_pcie_link_up(struct pcie_port *pp);
void dw_pcie_setup_rc(struct pcie_port *pp);
int dw_pcie_host_init(struct pcie_port *pp);