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[v5,2/2] PCI: dwc: add support to handle ZRX-DC Compliant PHYs

Message ID 1576241263-23817-3-git-send-email-anvesh.s@samsung.com
State New
Headers show
Series Add support to handle ZRX-DC Compliant PHYs | expand

Commit Message

Anvesh Salveru Dec. 13, 2019, 12:47 p.m. UTC
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.s@samsung.com>
Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
Changes w.r.t v4:
 - None

 drivers/pci/controller/dwc/pcie-designware.c | 6 ++++++
 drivers/pci/controller/dwc/pcie-designware.h | 4 ++++
 2 files changed, 10 insertions(+)
diff mbox series


diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 820488d..36a01b7 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -556,4 +556,10 @@  void dw_pcie_setup(struct dw_pcie *pci)
 		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);
+		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 5accdd6..36f7579 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -60,6 +60,9 @@ 
 #define PCIE_MSI_INTR0_MASK		0x82C
 #define PCIE_MSI_INTR0_STATUS		0x830
+#define PCIE_PORT_GEN3_RELATED		0x890
 #define PCIE_ATU_VIEWPORT		0x900
@@ -249,6 +252,7 @@  struct dw_pcie {
 	void __iomem		*atu_base;
 	u32			num_viewport;
 	u8			iatu_unroll_enabled;
+	bool			phy_zrxdc_compliant;
 	struct pcie_port	pp;
 	struct dw_pcie_ep	ep;
 	const struct dw_pcie_ops *ops;