diff mbox series

[V2,17/28] PCI: tegra: Fix PLLE power down issue due to CLKREQ# signal

Message ID 20190423092825.759-18-mmaddireddy@nvidia.com (mailing list archive)
State Superseded, archived
Headers show
Series Enable Tegra PCIe root port features | expand

Commit Message

Manikanta Maddireddy April 23, 2019, 9:28 a.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>
---
V2: Corrected the comment in driver

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

Comments

Thierry Reding May 9, 2019, 2:24 p.m. UTC | #1 
On Tue, Apr 23, 2019 at 02:58:14PM +0530, Manikanta Maddireddy wrote:
> 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>
> ---
> V2: Corrected the comment in driver
> 
>  drivers/pci/controller/pci-tegra.c | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)

Acked-by: Thierry Reding <treding@nvidia.com>
diff mbox series

Patch

diff --git a/drivers/pci/controller/pci-tegra.c b/drivers/pci/controller/pci-tegra.c
index 0de24cb66a71..f74930654443 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);