From: Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx>
Many platforms use DesignWare controller but the PHY can be different in
different platforms. If the PHY is compliant is to ZRX-DC specification it
helps in low power consumption during power states.
If current data rate is 8.0 GT/s or higher and PHY is not compliant to
ZRX-DC specification, then after every 100ms link should transition to
recovery state during the low power states.
DesignWare controller provides GEN3_ZRXDC_NONCOMPL field in
GEN3_RELATED_OFF to specify about ZRX-DC compliant PHY.
Platforms with ZRX-DC compliant PHY can set phy_zrxdc_compliant variable to
specify this property to the controller.
Signed-off-by: Anvesh Salveru <anvesh.salveru@xxxxxxxxx>
Signed-off-by: Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx>
Signed-off-by: Shradha Todi <shradha.t@xxxxxxxxxxx>
Cc: Jingoo Han <jingoohan1@xxxxxxxxx>
Cc: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Cc: Rob Herring <robh@xxxxxxxxxx>
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
---
drivers/pci/controller/dwc/pcie-designware.c | 6 ++++++
drivers/pci/controller/dwc/pcie-designware.h | 4 ++++
2 files changed, 10 insertions(+)
diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 645fa18..74590c7 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -722,4 +722,10 @@ void dw_pcie_setup(struct dw_pcie *pci)
PCIE_PL_CHK_REG_CHK_REG_START;
dw_pcie_writel_dbi(pci, PCIE_PL_CHK_REG_CONTROL_STATUS, val);
}
+
+ if (pci->phy_zrxdc_compliant) {
+ val = dw_pcie_readl_dbi(pci, PCIE_PORT_GEN3_RELATED);
+ val &= ~PORT_LOGIC_GEN3_ZRXDC_NONCOMPL;
+ dw_pcie_writel_dbi(pci, PCIE_PORT_GEN3_RELATED, val);
+ }
}
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 0207840..8b905a2 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -74,6 +74,9 @@
#define PCIE_MSI_INTR0_MASK 0x82C
#define PCIE_MSI_INTR0_STATUS 0x830
+#define PCIE_PORT_GEN3_RELATED 0x890
+#define PORT_LOGIC_GEN3_ZRXDC_NONCOMPL BIT(0)
+
#define PCIE_PORT_MULTI_LANE_CTRL 0x8C0
#define PORT_MLTI_UPCFG_SUPPORT BIT(7)
@@ -273,6 +276,7 @@ struct dw_pcie {
u8 n_fts[2];
bool iatu_unroll_enabled: 1;
bool io_cfg_atu_shared: 1;
+ bool phy_zrxdc_compliant;
};
#define to_dw_pcie_from_pp(port) container_of((port), struct dw_pcie, pp)
--
2.7.4
