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 <treding@nvidia.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
index c284e84..869a921 100644
--- a/drivers/pci/host/pci-tegra.c
+++ b/drivers/pci/host/pci-tegra.c
@@ -25,6 +25,7 @@
*/
#include <linux/clk.h>
+#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/export.h>
#include <linux/interrupt.h>
@@ -277,6 +278,7 @@
struct regulator *avdd_supply;
const struct tegra_pcie_soc_data *soc_data;
+ struct dentry *debugfs;
};
struct tegra_pcie_port {
@@ -1638,6 +1640,115 @@
};
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;
@@ -1692,6 +1803,13 @@
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;