[V5,24/27] PCI: tegra: Put PEX CLK & BIAS pads in DPD mode

Commit Message

Manikanta Maddireddy June 17, 2019, 5:39 p.m. UTC

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 <[e-mail]>
Acked-by: Thierry Reding <[e-mail]>
---
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(-)

Patch

diff --git a/drivers/pci/controller/pci-tegra.c b/drivers/pci/controller/pci-tegra.c
index 34c5cabd8e80..d3b9e6440dd6 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>
@@ -2838,6 +2839,7 @@  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;
@@ -2853,6 +2855,13 @@  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);
 
@@ -2862,7 +2871,7 @@  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);
@@ -2883,6 +2892,8 @@  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);