diff mbox series

[V6,17/27] PCI: tegra: Fix PLLE power down issue due to CLKREQ# signal

Message ID 20190618180206.4908-18-mmaddireddy@nvidia.com (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show
Series Enable Tegra PCIe root port features | expand

Commit Message

Manikanta Maddireddy June 18, 2019, 6:01 p.m. UTC 
Disable controllers which failed to link up and configure CLKREQ# signals
of these controllers as GPIO. This is required to avoid CLKREQ# signal of
inactive controllers interfering with PLLE power down sequence.

PCIE_CLKREQ_GPIO bits are defined only in Tegra186, however programming
these bits in other SoCs doesn't cause any side effects. Program these
bits for all Tegra SoCs to avoid conditional check.

Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
---
V6: No change

V5: No change

V4: No change

V3: No change

V2: Corrected the comment in driver

 drivers/pci/controller/pci-tegra.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/pci/controller/pci-tegra.c b/drivers/pci/controller/pci-tegra.c
index abb94595c76b..3d9028cecc18 100644
--- a/drivers/pci/controller/pci-tegra.c
+++ b/drivers/pci/controller/pci-tegra.c
@@ -160,6 +160,8 @@ 
 #define  AFI_PCIE_CONFIG_SM2TMS0_XBAR_CONFIG_211	(0x1 << 20)
 #define  AFI_PCIE_CONFIG_SM2TMS0_XBAR_CONFIG_411	(0x2 << 20)
 #define  AFI_PCIE_CONFIG_SM2TMS0_XBAR_CONFIG_111	(0x2 << 20)
+#define  AFI_PCIE_CONFIG_PCIE_CLKREQ_GPIO(x)		(1 << ((x) + 29))
+#define  AFI_PCIE_CONFIG_PCIE_CLKREQ_GPIO_ALL		(0x7 << 29)
 
 #define AFI_FUSE			0x104
 #define  AFI_FUSE_PCIE_T0_GEN2_DIS	(1 << 2)
@@ -741,6 +743,12 @@  static void tegra_pcie_port_disable(struct tegra_pcie_port *port)
 
 	value &= ~AFI_PEX_CTRL_REFCLK_EN;
 	afi_writel(port->pcie, value, ctrl);
+
+	/* disable PCIe port and set CLKREQ# as GPIO to allow PLLE power down */
+	value = afi_readl(port->pcie, AFI_PCIE_CONFIG);
+	value |= AFI_PCIE_CONFIG_PCIE_DISABLE(port->index);
+	value |= AFI_PCIE_CONFIG_PCIE_CLKREQ_GPIO(port->index);
+	afi_writel(port->pcie, value, AFI_PCIE_CONFIG);
 }
 
 static void tegra_pcie_port_free(struct tegra_pcie_port *port)
@@ -1153,9 +1161,12 @@  static void tegra_pcie_enable_controller(struct tegra_pcie *pcie)
 	value = afi_readl(pcie, AFI_PCIE_CONFIG);
 	value &= ~AFI_PCIE_CONFIG_SM2TMS0_XBAR_CONFIG_MASK;
 	value |= AFI_PCIE_CONFIG_PCIE_DISABLE_ALL | pcie->xbar_config;
+	value |= AFI_PCIE_CONFIG_PCIE_CLKREQ_GPIO_ALL;
 
-	list_for_each_entry(port, &pcie->ports, list)
+	list_for_each_entry(port, &pcie->ports, list) {
 		value &= ~AFI_PCIE_CONFIG_PCIE_DISABLE(port->index);
+		value &= ~AFI_PCIE_CONFIG_PCIE_CLKREQ_GPIO(port->index);
+	}
 
 	afi_writel(pcie, value, AFI_PCIE_CONFIG);