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From:   Vidya Sagar <vidyas@nvidia.com>
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        <kthota@nvidia.com>, <mmaddireddy@nvidia.com>, <vidyas@nvidia.com>,
        <sagar.tv@gmail.com>
Subject: [PATCH V1 3/4] PCI: tegra194: Add support to configure a pluggable slot
Date:   Sat, 1 Oct 2022 00:57:46 +0530
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Add support to configure a slot as a pluggable slot by not power-gating
the respective controller based on the DT property "hotplug-gpios".

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
 drivers/pci/controller/dwc/pcie-tegra194.c | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 2600304522eb..0370e881422d 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -280,6 +280,8 @@ struct tegra_pcie_dw {
 	unsigned int phy_count;
 	struct phy **phys;
 
+	bool slot_pluggable;
+
 	struct dentry *debugfs;
 
 	/* Endpoint mode specific */
@@ -1089,6 +1091,7 @@ static int tegra_pcie_dw_parse_dt(struct tegra_pcie_dw *pcie)
 {
 	struct platform_device *pdev = to_platform_device(pcie->dev);
 	struct device_node *np = pcie->dev->of_node;
+	struct property *prop;
 	int ret;
 
 	pcie->dbi_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
@@ -1158,6 +1161,10 @@ static int tegra_pcie_dw_parse_dt(struct tegra_pcie_dw *pcie)
 		pcie->enable_srns =
 			of_property_read_bool(np, "nvidia,enable-srns");
 
+	prop = of_find_property(np, "hotplug-gpios", NULL);
+	if (prop)
+		pcie->slot_pluggable = true;
+
 	if (pcie->of_data->mode == DW_PCIE_RC_TYPE)
 		return 0;
 
@@ -1655,7 +1662,7 @@ static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie)
 	}
 
 	pcie->link_state = tegra_pcie_dw_link_up(&pcie->pci);
-	if (!pcie->link_state) {
+	if (!pcie->link_state && !pcie->slot_pluggable) {
 		ret = -ENOMEDIUM;
 		goto fail_host_init;
 	}
@@ -2267,7 +2274,7 @@ static int tegra_pcie_dw_remove(struct platform_device *pdev)
 	struct tegra_pcie_dw *pcie = platform_get_drvdata(pdev);
 
 	if (pcie->of_data->mode == DW_PCIE_RC_TYPE) {
-		if (!pcie->link_state)
+		if (!pcie->link_state && !pcie->slot_pluggable)
 			return 0;
 
 		debugfs_remove_recursive(pcie->debugfs);
@@ -2296,7 +2303,7 @@ static int tegra_pcie_dw_suspend_late(struct device *dev)
 		return -EPERM;
 	}
 
-	if (!pcie->link_state)
+	if (!pcie->link_state && !pcie->slot_pluggable)
 		return 0;
 
 	/* Enable HW_HOT_RST mode */
@@ -2315,7 +2322,7 @@ static int tegra_pcie_dw_suspend_noirq(struct device *dev)
 {
 	struct tegra_pcie_dw *pcie = dev_get_drvdata(dev);
 
-	if (!pcie->link_state)
+	if (!pcie->link_state && !pcie->slot_pluggable)
 		return 0;
 
 	tegra_pcie_downstream_dev_to_D0(pcie);
@@ -2330,7 +2337,7 @@ static int tegra_pcie_dw_resume_noirq(struct device *dev)
 	struct tegra_pcie_dw *pcie = dev_get_drvdata(dev);
 	int ret;
 
-	if (!pcie->link_state)
+	if (!pcie->link_state && !pcie->slot_pluggable)
 		return 0;
 
 	ret = tegra_pcie_config_controller(pcie, true);
@@ -2366,7 +2373,7 @@ static int tegra_pcie_dw_resume_early(struct device *dev)
 		return -ENOTSUPP;
 	}
 
-	if (!pcie->link_state)
+	if (!pcie->link_state && !pcie->slot_pluggable)
 		return 0;
 
 	/* Disable HW_HOT_RST mode */
@@ -2388,7 +2395,7 @@ static void tegra_pcie_dw_shutdown(struct platform_device *pdev)
 	struct tegra_pcie_dw *pcie = platform_get_drvdata(pdev);
 
 	if (pcie->of_data->mode == DW_PCIE_RC_TYPE) {
-		if (!pcie->link_state)
+		if (!pcie->link_state && !pcie->slot_pluggable)
 			return;
 
 		debugfs_remove_recursive(pcie->debugfs);
-- 
2.17.1