PCI: tegra: Add debugfs support

Provide a debugfs file ("pcie/ports") that shows the current link status
for each root port.

Signed-off-by: Thierry Reding <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Reviewed-by: Stephen Warren <[email protected]>

diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
index c284e841e3ea0dc2a25e19012ef40f10d2994165..869a9213ccd6c82651698c919390ac7c585fadd3 100644 (file)
--- a/drivers/pci/host/pci-tegra.c
+++ b/drivers/pci/host/pci-tegra.c
@@ -25,6 +25,7 @@
  */
 
 #include <linux/clk.h>
  */
 
 #include <linux/clk.h>

+#include <linux/debugfs.h>

 #include <linux/delay.h>
 #include <linux/export.h>
 #include <linux/interrupt.h>
 #include <linux/delay.h>
 #include <linux/export.h>
 #include <linux/interrupt.h>


@@ -277,6 +278,7 @@ struct tegra_pcie {
        struct regulator *avdd_supply;
 
        const struct tegra_pcie_soc_data *soc_data;
        struct regulator *avdd_supply;
 
        const struct tegra_pcie_soc_data *soc_data;

+       struct dentry *debugfs;

 };
 
 struct tegra_pcie_port {
 };
 
 struct tegra_pcie_port {


@@ -1638,6 +1640,115 @@ static const struct of_device_id tegra_pcie_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, tegra_pcie_of_match);
 
 };
 MODULE_DEVICE_TABLE(of, tegra_pcie_of_match);
 

+static void *tegra_pcie_ports_seq_start(struct seq_file *s, loff_t *pos)
+{
+       struct tegra_pcie *pcie = s->private;
+
+       if (list_empty(&pcie->ports))
+               return NULL;
+
+       seq_printf(s, "Index  Status\n");
+
+       return seq_list_start(&pcie->ports, *pos);
+}
+
+static void *tegra_pcie_ports_seq_next(struct seq_file *s, void *v, loff_t *pos)
+{
+       struct tegra_pcie *pcie = s->private;
+
+       return seq_list_next(v, &pcie->ports, pos);
+}
+
+static void tegra_pcie_ports_seq_stop(struct seq_file *s, void *v)
+{
+}
+
+static int tegra_pcie_ports_seq_show(struct seq_file *s, void *v)
+{
+       bool up = false, active = false;
+       struct tegra_pcie_port *port;
+       unsigned int value;
+
+       port = list_entry(v, struct tegra_pcie_port, list);
+
+       value = readl(port->base + RP_VEND_XP);
+
+       if (value & RP_VEND_XP_DL_UP)
+               up = true;
+
+       value = readl(port->base + RP_LINK_CONTROL_STATUS);
+
+       if (value & RP_LINK_CONTROL_STATUS_DL_LINK_ACTIVE)
+               active = true;
+
+       seq_printf(s, "%2u     ", port->index);
+
+       if (up)
+               seq_printf(s, "up");
+
+       if (active) {
+               if (up)
+                       seq_printf(s, ", ");
+
+               seq_printf(s, "active");
+       }
+
+       seq_printf(s, "\n");
+       return 0;
+}
+
+static const struct seq_operations tegra_pcie_ports_seq_ops = {
+       .start = tegra_pcie_ports_seq_start,
+       .next = tegra_pcie_ports_seq_next,
+       .stop = tegra_pcie_ports_seq_stop,
+       .show = tegra_pcie_ports_seq_show,
+};
+
+static int tegra_pcie_ports_open(struct inode *inode, struct file *file)
+{
+       struct tegra_pcie *pcie = inode->i_private;
+       struct seq_file *s;
+       int err;
+
+       err = seq_open(file, &tegra_pcie_ports_seq_ops);
+       if (err)
+               return err;
+
+       s = file->private_data;
+       s->private = pcie;
+
+       return 0;
+}
+
+static const struct file_operations tegra_pcie_ports_ops = {
+       .owner = THIS_MODULE,
+       .open = tegra_pcie_ports_open,
+       .read = seq_read,
+       .llseek = seq_lseek,
+       .release = seq_release,
+};
+
+static int tegra_pcie_debugfs_init(struct tegra_pcie *pcie)
+{
+       struct dentry *file;
+
+       pcie->debugfs = debugfs_create_dir("pcie", NULL);
+       if (!pcie->debugfs)
+               return -ENOMEM;
+
+       file = debugfs_create_file("ports", S_IFREG | S_IRUGO, pcie->debugfs,
+                                  pcie, &tegra_pcie_ports_ops);
+       if (!file)
+               goto remove;
+
+       return 0;
+
+remove:
+       debugfs_remove_recursive(pcie->debugfs);
+       pcie->debugfs = NULL;
+       return -ENOMEM;
+}
+

 static int tegra_pcie_probe(struct platform_device *pdev)
 {
        const struct of_device_id *match;
 static int tegra_pcie_probe(struct platform_device *pdev)
 {
        const struct of_device_id *match;


@@ -1692,6 +1803,13 @@ static int tegra_pcie_probe(struct platform_device *pdev)
                goto disable_msi;
        }
 
                goto disable_msi;
        }
 

+       if (IS_ENABLED(CONFIG_DEBUG_FS)) {
+               err = tegra_pcie_debugfs_init(pcie);
+               if (err < 0)
+                       dev_err(&pdev->dev, "failed to setup debugfs: %d\n",
+                               err);
+       }
+

        platform_set_drvdata(pdev, pcie);
        return 0;
 
        platform_set_drvdata(pdev, pcie);
        return 0;