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 <rajat.khandelwal@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
---

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 34e4188a40ff..4969f4a2d445 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;
 }
 
@@ -719,6 +754,8 @@ static int pmc_usb_remove(struct platform_device *pdev)
 
 	acpi_dev_put(pmc->iom_adev);
 
+	debugfs_remove(pmc->dentry);
+
 	return 0;
 }
 
@@ -737,7 +774,20 @@ static struct platform_driver pmc_usb_driver = {
 	.remove = 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 <heikki.krogerus@linux.intel.com>");
 MODULE_LICENSE("GPL v2");
-- 
2.34.1

On Wed, May 24, 2023 at 04:17:54PM +0530, Rajat Khandelwal wrote:
> 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 <rajat.khandelwal@linux.intel.com>
> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

Does not apply to my tree :(

Hi,

On 5/29/2023 7:48 PM, Greg KH wrote:
> On Wed, May 24, 2023 at 04:17:54PM +0530, Rajat Khandelwal wrote:
>> 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 <rajat.khandelwal@linux.intel.com>
>> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> Does not apply to my tree :(

I have pushed the patch on top of the Linus's tree.
Had a quick check with the USB Linux tree and seems like its a lot
behind?
Can you please confirm once and come back?

Thanks
Rajat

On Tue, May 30, 2023 at 02:45:03PM +0530, Rajat Khandelwal wrote:
> Hi,
> 
> On 5/29/2023 7:48 PM, Greg KH wrote:
> > On Wed, May 24, 2023 at 04:17:54PM +0530, Rajat Khandelwal wrote:
> > > 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 <rajat.khandelwal@linux.intel.com>
> > > Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> > Does not apply to my tree :(
> 
> I have pushed the patch on top of the Linus's tree.
> Had a quick check with the USB Linux tree and seems like its a lot
> behind?

What branch did you use?

Please use the usb-next branch of
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git, which as
of right now, is at 6.4-rc4 + a bunch of USB-specific patches.

thanks,

greg k-h

Hi,

On 5/30/2023 2:57 PM, Greg KH wrote:
> On Tue, May 30, 2023 at 02:45:03PM +0530, Rajat Khandelwal wrote:
>> Hi,
>>
>> On 5/29/2023 7:48 PM, Greg KH wrote:
>>> On Wed, May 24, 2023 at 04:17:54PM +0530, Rajat Khandelwal wrote:
>>>> 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 <rajat.khandelwal@linux.intel.com>
>>>> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
>>> Does not apply to my tree :(
>> I have pushed the patch on top of the Linus's tree.
>> Had a quick check with the USB Linux tree and seems like its a lot
>> behind?
> What branch did you use?
>
> Please use the usb-next branch of
> git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git, which as
> of right now, is at 6.4-rc4 + a bunch of USB-specific patches.

I see. There is one commit additional in the usb-next tree:
ef0a3642b320 usb: typec: intel_pmc_mux: Convert to platform remove callback returning void

Anyways, do you want me to re-work the patch for the usb-next branch?

Thanks
Rajat

>
> thanks,
>
> greg k-h

On Tue, May 30, 2023 at 03:06:15PM +0530, Rajat Khandelwal wrote:
> Hi,
> 
> On 5/30/2023 2:57 PM, Greg KH wrote:
> > On Tue, May 30, 2023 at 02:45:03PM +0530, Rajat Khandelwal wrote:
> > > Hi,
> > > 
> > > On 5/29/2023 7:48 PM, Greg KH wrote:
> > > > On Wed, May 24, 2023 at 04:17:54PM +0530, Rajat Khandelwal wrote:
> > > > > 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 <rajat.khandelwal@linux.intel.com>
> > > > > Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> > > > Does not apply to my tree :(
> > > I have pushed the patch on top of the Linus's tree.
> > > Had a quick check with the USB Linux tree and seems like its a lot
> > > behind?
> > What branch did you use?
> > 
> > Please use the usb-next branch of
> > git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git, which as
> > of right now, is at 6.4-rc4 + a bunch of USB-specific patches.
> 
> I see. There is one commit additional in the usb-next tree:
> ef0a3642b320 usb: typec: intel_pmc_mux: Convert to platform remove callback returning void

One?  I count a lot more:

$ git log --oneline main..usb-next | wc -l
143

> Anyways, do you want me to re-work the patch for the usb-next branch?

Given that I can not take the patch as-is, it's up to you to rebase it
if you wish to have it accepted.

Isn't this all covered in the Intel kernel developer training class?

thanks,

greg k-h

Hi,

On 5/30/2023 3:14 PM, Greg KH wrote:
> On Tue, May 30, 2023 at 03:06:15PM +0530, Rajat Khandelwal wrote:
>> Hi,
>>
>> On 5/30/2023 2:57 PM, Greg KH wrote:
>>> On Tue, May 30, 2023 at 02:45:03PM +0530, Rajat Khandelwal wrote:
>>>> Hi,
>>>>
>>>> On 5/29/2023 7:48 PM, Greg KH wrote:
>>>>> On Wed, May 24, 2023 at 04:17:54PM +0530, Rajat Khandelwal wrote:
>>>>>> 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 <rajat.khandelwal@linux.intel.com>
>>>>>> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
>>>>> Does not apply to my tree :(
>>>> I have pushed the patch on top of the Linus's tree.
>>>> Had a quick check with the USB Linux tree and seems like its a lot
>>>> behind?
>>> What branch did you use?
>>>
>>> Please use the usb-next branch of
>>> git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git, which as
>>> of right now, is at 6.4-rc4 + a bunch of USB-specific patches.
>> I see. There is one commit additional in the usb-next tree:
>> ef0a3642b320 usb: typec: intel_pmc_mux: Convert to platform remove callback returning void
> One?  I count a lot more:
>
> $ git log --oneline main..usb-next | wc -l
> 143

I was referring to Linus's master branch. :)

>
>> Anyways, do you want me to re-work the patch for the usb-next branch?
> Given that I can not take the patch as-is, it's up to you to rebase it
> if you wish to have it accepted.

Ok. I will make a v6 on top of usb-next.

Thanks
Rajat

>
> Isn't this all covered in the Intel kernel developer training class?
>
> thanks,
>
> greg k-h