2023-05-31 11:03:17

by Rajat Khandelwal

[permalink] [raw]
Subject: [PATCH v6] usb: typec: intel_pmc_mux: Expose IOM port status to debugfs

IOM status has a crucial role during debugging to check the
current state of the type-C port.
There are ways to fetch the status, but all those require the
IOM port status offset, which could change with platform.

Make a debugfs directory for intel_pmc_mux and expose the status
under it per port basis.

Signed-off-by: Rajat Khandelwal <[email protected]>
Reviewed-by: Heikki Krogerus <[email protected]>
---

v6: Re-work the patch on usb-next

v5: Remove #ifdef macro for the dentry in struct pmc_usb

v4:
1. Maintain a root directory for PMC module and incorporate devices
under it
2. Add the debugfs module under '/sys/kernel/debug/usb'
3. Use the platform device 'pmc->dev' to assign the device's name

v3: Allocate the debugfs directory name for the platform device with
its ACPI dev name included

v2:
1. Remove static declaration of the debugfs root for 'intel_pmc_mux'
2. Remove explicitly defined one-liner functions

drivers/usb/typec/mux/intel_pmc_mux.c | 52 ++++++++++++++++++++++++++-
1 file changed, 51 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/typec/mux/intel_pmc_mux.c b/drivers/usb/typec/mux/intel_pmc_mux.c
index e049eadb591e..5e8edf3881c0 100644
--- a/drivers/usb/typec/mux/intel_pmc_mux.c
+++ b/drivers/usb/typec/mux/intel_pmc_mux.c
@@ -15,6 +15,8 @@
#include <linux/usb/typec_mux.h>
#include <linux/usb/typec_dp.h>
#include <linux/usb/typec_tbt.h>
+#include <linux/debugfs.h>
+#include <linux/usb.h>

#include <asm/intel_scu_ipc.h>

@@ -143,8 +145,12 @@ struct pmc_usb {
struct acpi_device *iom_adev;
void __iomem *iom_base;
u32 iom_port_status_offset;
+
+ struct dentry *dentry;
};

+static struct dentry *pmc_mux_debugfs_root;
+
static void update_port_status(struct pmc_usb_port *port)
{
u8 port_num;
@@ -639,6 +645,29 @@ static int pmc_usb_probe_iom(struct pmc_usb *pmc)
return 0;
}

+static int port_iom_status_show(struct seq_file *s, void *unused)
+{
+ struct pmc_usb_port *port = s->private;
+
+ update_port_status(port);
+ seq_printf(s, "0x%08x\n", port->iom_status);
+
+ return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(port_iom_status);
+
+static void pmc_mux_port_debugfs_init(struct pmc_usb_port *port)
+{
+ struct dentry *debugfs_dir;
+ char name[6];
+
+ snprintf(name, sizeof(name), "port%d", port->usb3_port - 1);
+
+ debugfs_dir = debugfs_create_dir(name, port->pmc->dentry);
+ debugfs_create_file("iom_status", 0400, debugfs_dir, port,
+ &port_iom_status_fops);
+}
+
static int pmc_usb_probe(struct platform_device *pdev)
{
struct fwnode_handle *fwnode = NULL;
@@ -674,6 +703,8 @@ static int pmc_usb_probe(struct platform_device *pdev)
if (ret)
return ret;

+ pmc->dentry = debugfs_create_dir(dev_name(pmc->dev), pmc_mux_debugfs_root);
+
/*
* For every physical USB connector (USB2 and USB3 combo) there is a
* child ACPI device node under the PMC mux ACPI device object.
@@ -688,6 +719,8 @@ static int pmc_usb_probe(struct platform_device *pdev)
fwnode_handle_put(fwnode);
goto err_remove_ports;
}
+
+ pmc_mux_port_debugfs_init(&pmc->port[i]);
}

platform_set_drvdata(pdev, pmc);
@@ -703,6 +736,8 @@ static int pmc_usb_probe(struct platform_device *pdev)

acpi_dev_put(pmc->iom_adev);

+ debugfs_remove(pmc->dentry);
+
return ret;
}

@@ -718,6 +753,8 @@ static void pmc_usb_remove(struct platform_device *pdev)
}

acpi_dev_put(pmc->iom_adev);
+
+ debugfs_remove(pmc->dentry);
}

static const struct acpi_device_id pmc_usb_acpi_ids[] = {
@@ -735,7 +772,20 @@ static struct platform_driver pmc_usb_driver = {
.remove_new = pmc_usb_remove,
};

-module_platform_driver(pmc_usb_driver);
+static int __init pmc_usb_init(void)
+{
+ pmc_mux_debugfs_root = debugfs_create_dir("intel_pmc_mux", usb_debug_root);
+
+ return platform_driver_register(&pmc_usb_driver);
+}
+module_init(pmc_usb_init);
+
+static void __exit pmc_usb_exit(void)
+{
+ platform_driver_unregister(&pmc_usb_driver);
+ debugfs_remove(pmc_mux_debugfs_root);
+}
+module_exit(pmc_usb_exit);

MODULE_AUTHOR("Heikki Krogerus <[email protected]>");
MODULE_LICENSE("GPL v2");
--
2.34.1