[PATCH v4 10/12] PCI: rockship-ep: Implement the pci_epc_ops::stop_link() operation

[Damien Le Moal]

Define the EPC operation ->stop() for the Rockchip endpoint driver with
the function rockchip_pcie_ep_stop(). This function disables link
training and the controller configuration, as the reverse to what
the start operation defined with rockchip_pcie_ep_start() does.

Signed-off-by: Damien Le Moal <dlemoal at kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam at linaro.org>
---
 drivers/pci/controller/pcie-rockchip-ep.c | 13 +++++++++++++
 drivers/pci/controller/pcie-rockchip.h    |  1 +
 2 files changed, 14 insertions(+)

diff --git a/drivers/pci/controller/pcie-rockchip-ep.c b/drivers/pci/controller/pcie-rockchip-ep.c
index 56dd4466cae5..431862a87e04 100644
--- a/drivers/pci/controller/pcie-rockchip-ep.c
+++ b/drivers/pci/controller/pcie-rockchip-ep.c
@@ -468,6 +468,18 @@ static int rockchip_pcie_ep_start(struct pci_epc *epc)
 	return 0;
 }
 
+static void rockchip_pcie_ep_stop(struct pci_epc *epc)
+{
+	struct rockchip_pcie_ep *ep = epc_get_drvdata(epc);
+	struct rockchip_pcie *rockchip = &ep->rockchip;
+
+	/* Stop link training and disable configuration */
+	rockchip_pcie_write(rockchip,
+			    PCIE_CLIENT_CONF_DISABLE |
+			    PCIE_CLIENT_LINK_TRAIN_DISABLE,
+			    PCIE_CLIENT_CONFIG);
+}
+
 static const struct pci_epc_features rockchip_pcie_epc_features = {
 	.linkup_notifier = false,
 	.msi_capable = true,
@@ -492,6 +504,7 @@ static const struct pci_epc_ops rockchip_pcie_epc_ops = {
 	.get_msi	= rockchip_pcie_ep_get_msi,
 	.raise_irq	= rockchip_pcie_ep_raise_irq,
 	.start		= rockchip_pcie_ep_start,
+	.stop		= rockchip_pcie_ep_stop,
 	.get_features	= rockchip_pcie_ep_get_features,
 };
 
diff --git a/drivers/pci/controller/pcie-rockchip.h b/drivers/pci/controller/pcie-rockchip.h
index 30398156095f..0263f158ee8d 100644
--- a/drivers/pci/controller/pcie-rockchip.h
+++ b/drivers/pci/controller/pcie-rockchip.h
@@ -32,6 +32,7 @@
 #define   PCIE_CLIENT_CONF_ENABLE	  HIWORD_UPDATE_BIT(0x0001)
 #define   PCIE_CLIENT_CONF_DISABLE       HIWORD_UPDATE(0x0001, 0)
 #define   PCIE_CLIENT_LINK_TRAIN_ENABLE	  HIWORD_UPDATE_BIT(0x0002)
+#define   PCIE_CLIENT_LINK_TRAIN_DISABLE  HIWORD_UPDATE(0x0002, 0)
 #define   PCIE_CLIENT_ARI_ENABLE	  HIWORD_UPDATE_BIT(0x0008)
 #define   PCIE_CLIENT_CONF_LANE_NUM(x)	  HIWORD_UPDATE(0x0030, ENCODE_LANES(x))
 #define   PCIE_CLIENT_MODE_RC		  HIWORD_UPDATE_BIT(0x0040)
-- 
2.47.0