[PATCH V6 24/27] PCI: tegra: Put PEX CLK & BIAS pads in DPD mode

[Manikanta Maddireddy <mmaddireddy@nvidia.com>]

In Tegra210 AFI design has clamp value for the BIAS pad as 0, which keeps
the bias pad in non power down mode. This is leading to power consumption
of 2 mW in BIAS pad, even if the PCIe partition is powergated. To avoid
unnecessary power consumption, put PEX CLK & BIAS pads in deep power down
mode when PCIe partition is power gated.

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: Using standard pinctrl functions to apply default and idle states

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

diff --git a/drivers/pci/controller/pci-tegra.c b/drivers/pci/controller/pci-tegra.c
index 347897271943..d2841532ff0e 100644
--- a/drivers/pci/controller/pci-tegra.c
+++ b/drivers/pci/controller/pci-tegra.c
@@ -30,6 +30,7 @@
 #include <linux/of_platform.h>
 #include <linux/pci.h>
 #include <linux/phy/phy.h>
+#include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
 #include <linux/reset.h>
 #include <linux/sizes.h>
@@ -2834,6 +2835,7 @@ static int __maybe_unused tegra_pcie_pm_suspend(struct device *dev)
 	if (IS_ENABLED(CONFIG_PCI_MSI))
 		tegra_pcie_disable_msi(pcie);
 
+	pinctrl_pm_select_idle_state(dev);
 	tegra_pcie_power_off(pcie);
 
 	return 0;
@@ -2849,6 +2851,13 @@ static int __maybe_unused tegra_pcie_pm_resume(struct device *dev)
 		dev_err(dev, "tegra pcie power on fail: %d\n", err);
 		return err;
 	}
+
+	err = pinctrl_pm_select_default_state(dev);
+	if (err < 0) {
+		dev_err(dev, "failed to disable PCIe IO DPD: %d\n", err);
+		goto poweroff;
+	}
+
 	tegra_pcie_enable_controller(pcie);
 	tegra_pcie_setup_translations(pcie);
 
@@ -2858,7 +2867,7 @@ static int __maybe_unused tegra_pcie_pm_resume(struct device *dev)
 	err = clk_prepare_enable(pcie->pex_clk);
 	if (err) {
 		dev_err(dev, "failed to enable PEX clock: %d\n", err);
-		goto poweroff;
+		goto pex_dpd_enable;
 	}
 
 	reset_control_deassert(pcie->pex_rst);
@@ -2879,6 +2888,8 @@ static int __maybe_unused tegra_pcie_pm_resume(struct device *dev)
 disable_pex_clk:
 	reset_control_assert(pcie->pex_rst);
 	clk_disable_unprepare(pcie->pex_clk);
+pex_dpd_enable:
+	pinctrl_pm_select_idle_state(dev);
 poweroff:
 	tegra_pcie_power_off(pcie);
 
-- 
2.17.1