Hi Kishon,
Thank you for your comment.
On 2021/01/28 23:29, Kishon Vijay Abraham I wrote:
Hi Kunihiko,
On 24/01/21 8:39 pm, Kunihiko Hayashi wrote:
Set the polling function and call the init function to enable EPC restart
management. The polling function detects that the bus-reset signal is a
rising edge.
Signed-off-by: Kunihiko Hayashi <[email protected]>
---
drivers/pci/controller/dwc/Kconfig | 1 +
drivers/pci/controller/dwc/pcie-uniphier-ep.c | 44 ++++++++++++++++++++++++++-
2 files changed, 44 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/controller/dwc/Kconfig
b/drivers/pci/controller/dwc/Kconfig
index 22c5529..90d400a 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -302,6 +302,7 @@ config PCIE_UNIPHIER_EP
depends on OF && HAS_IOMEM
depends on PCI_ENDPOINT
select PCIE_DW_EP
+ select PCI_ENDPOINT_RESTART
help
Say Y here if you want PCIe endpoint controller support on
UniPhier SoCs. This driver supports Pro5 SoC.
diff --git a/drivers/pci/controller/dwc/pcie-uniphier-ep.c
b/drivers/pci/controller/dwc/pcie-uniphier-ep.c
index 69810c6..9d83850 100644
--- a/drivers/pci/controller/dwc/pcie-uniphier-ep.c
+++ b/drivers/pci/controller/dwc/pcie-uniphier-ep.c
@@ -26,6 +26,7 @@
#define PCL_RSTCTRL_PIPE3 BIT(0)
#define PCL_RSTCTRL1 0x0020
+#define PCL_RSTCTRL_PERST_MON BIT(16)
#define PCL_RSTCTRL_PERST BIT(0)
#define PCL_RSTCTRL2 0x0024
@@ -60,6 +61,7 @@ struct uniphier_pcie_ep_priv {
struct clk *clk, *clk_gio;
struct reset_control *rst, *rst_gio;
struct phy *phy;
+ bool bus_reset_status;
const struct pci_epc_features *features;
};
@@ -212,6 +214,41 @@ uniphier_pcie_get_features(struct dw_pcie_ep *ep)
return priv->features;
}
+static bool uniphier_pcie_ep_poll_reset(void *data)
+{
+ struct uniphier_pcie_ep_priv *priv = data;
+ bool ret, status;
+
+ if (!priv)
+ return false;
+
+ status = !(readl(priv->base + PCL_RSTCTRL1) & PCL_RSTCTRL_PERST_MON);
+
+ /* return true if the rising edge of bus reset is detected */
+ ret = !!(status == false && priv->bus_reset_status == true);
+ priv->bus_reset_status = status;
I'm still not convinced about having a separate library for restart
management but shouldn't we reset the function driver on falling edge?
I understand your opnion well.
There might not be enough way to give controller-specific features
to handle "restart" as a common function.
After the rising edge the host expects the endpoint to be ready.
I see. I didn't consider that restart was completed just after
the rising edge.
Why not use the CORE_INIT (core_init_notifier) infrastructure?
I don't follow the CORE_INIT yet, so I'll try to introduce it
into the driver. However, our current controller doesn't have
an interrupt that detects PERST like pcie-tegra194.
I think the driver needs a thread for polling PERST like patch 2/3.
Thank you,
---
Best Regards
Kunihiko Hayashi
