[PATCH] soundwire: debugfs: add root-level peripherals table

[PATCH] soundwire: debugfs: add root-level peripherals table

[Bard Liao]

The table will let user know what peripherals are listed and get the
detected status by the dev_num.

Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
---
 drivers/soundwire/debugfs.c | 72 +++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)

diff --git a/drivers/soundwire/debugfs.c b/drivers/soundwire/debugfs.c
index 2905ec19b838..3cc3428df6a4 100644
--- a/drivers/soundwire/debugfs.c
+++ b/drivers/soundwire/debugfs.c
@@ -9,12 +9,82 @@
 #include <linux/pm_runtime.h>
 #include <linux/slab.h>
 #include <linux/soundwire/sdw.h>
+#include <linux/soundwire/sdw_type.h>
 #include <linux/soundwire/sdw_registers.h>
 #include <linux/string_choices.h>
 #include "bus.h"
 
 static struct dentry *sdw_debugfs_root;
 
+#define SDW_PERIPH_HEADER_FMT "%-28s %-7s %-16s %-6s %-7s %-8s %-9s %-11s\n"
+#define SDW_PERIPH_ENTRY_FMT  "%-28s %-7u %#016llx %-6.4x %-7.4x %-8.2x %-9.2x %-11.1x\n"
+
+static u64 sdw_slave_addr_from_id(struct sdw_bus *bus,
+				 const struct sdw_slave_id *id)
+{
+	u64 addr = 0;
+	u8 unique_id = id->unique_id;
+
+	if (unique_id == SDW_IGNORED_UNIQUE_ID)
+		unique_id = 0;
+
+	addr |= FIELD_PREP(SDW_DISCO_LINK_ID_MASK, bus->link_id);
+	addr |= FIELD_PREP(SDW_VERSION_MASK, id->sdw_version);
+	addr |= FIELD_PREP(SDW_UNIQUE_ID_MASK, unique_id);
+	addr |= FIELD_PREP(SDW_MFG_ID_MASK, id->mfg_id);
+	addr |= FIELD_PREP(SDW_PART_ID_MASK, id->part_id);
+	addr |= FIELD_PREP(SDW_CLASS_ID_MASK, id->class_id);
+
+	return addr;
+}
+
+static void sdw_dump_bus_peripherals(struct seq_file *s_file, struct sdw_bus *bus)
+{
+	struct sdw_slave *slave;
+	u64 addr;
+
+	seq_printf(s_file, "master-%d-%d\n",
+		   bus->controller_id, bus->link_id);
+	seq_printf(s_file, SDW_PERIPH_HEADER_FMT,
+		   "name", "dev_num", "addr", "mfg_id", "part_id",
+		   "class_id", "unique_id", "sdw_version");
+
+	mutex_lock(&bus->bus_lock);
+	list_for_each_entry(slave, &bus->slaves, node) {
+		addr = sdw_slave_addr_from_id(bus, &slave->id);
+		seq_printf(s_file, SDW_PERIPH_ENTRY_FMT,
+			   dev_name(&slave->dev), slave->dev_num,
+			   addr,
+			   slave->id.mfg_id, slave->id.part_id,
+			   slave->id.class_id, slave->id.unique_id,
+			   slave->id.sdw_version);
+	}
+	mutex_unlock(&bus->bus_lock);
+
+	seq_putc(s_file, '\n');
+}
+
+static int sdw_root_peripherals_dump(struct device *dev, void *data)
+{
+	struct sdw_master_device *md;
+	struct seq_file *s_file = data;
+
+	if (dev->type != &sdw_master_type)
+		return 0;
+
+	md = dev_to_sdw_master_device(dev);
+	sdw_dump_bus_peripherals(s_file, md->bus);
+
+	return 0;
+}
+
+static int sdw_root_peripherals_show(struct seq_file *s_file, void *data)
+{
+	return bus_for_each_dev(&sdw_bus_type, NULL, s_file,
+				sdw_root_peripherals_dump);
+}
+DEFINE_SHOW_ATTRIBUTE(sdw_root_peripherals);
+
 void sdw_bus_debugfs_init(struct sdw_bus *bus)
 {
 	char name[16];
@@ -375,6 +445,8 @@ void sdw_debugfs_init(void)
 		firmware_file = kstrdup("", GFP_KERNEL);
 
 	sdw_debugfs_root = debugfs_create_dir("soundwire", NULL);
+	debugfs_create_file("peripherals", 0400, sdw_debugfs_root, NULL,
+			    &sdw_root_peripherals_fops);
 }
 
 void sdw_debugfs_exit(void)
-- 
2.43.0

Re: [PATCH] soundwire: debugfs: add root-level peripherals table

[Pierre-Louis Bossart]

On 9/2/26 10:18, Bard Liao wrote:
> The table will let user know what peripherals are listed and get the
> detected status by the dev_num.

This sounds useful indeed, but does this need to be in debugfs?

We already have a sysfs entry for every peripheral listed in ACPI. Each
peripheral will have a set of properties extracted from DisCo tables,
could we piggy-back on all this and just expose the dev_num?

> 
> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
> ---
>  drivers/soundwire/debugfs.c | 72 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 72 insertions(+)
> 
> diff --git a/drivers/soundwire/debugfs.c b/drivers/soundwire/debugfs.c
> index 2905ec19b838..3cc3428df6a4 100644
> --- a/drivers/soundwire/debugfs.c
> +++ b/drivers/soundwire/debugfs.c
> @@ -9,12 +9,82 @@
>  #include <linux/pm_runtime.h>
>  #include <linux/slab.h>
>  #include <linux/soundwire/sdw.h>
> +#include <linux/soundwire/sdw_type.h>
>  #include <linux/soundwire/sdw_registers.h>
>  #include <linux/string_choices.h>
>  #include "bus.h"
>  
>  static struct dentry *sdw_debugfs_root;
>  
> +#define SDW_PERIPH_HEADER_FMT "%-28s %-7s %-16s %-6s %-7s %-8s %-9s %-11s\n"
> +#define SDW_PERIPH_ENTRY_FMT  "%-28s %-7u %#016llx %-6.4x %-7.4x %-8.2x %-9.2x %-11.1x\n"
> +
> +static u64 sdw_slave_addr_from_id(struct sdw_bus *bus,
> +				 const struct sdw_slave_id *id)
> +{
> +	u64 addr = 0;
> +	u8 unique_id = id->unique_id;
> +
> +	if (unique_id == SDW_IGNORED_UNIQUE_ID)
> +		unique_id = 0;
> +
> +	addr |= FIELD_PREP(SDW_DISCO_LINK_ID_MASK, bus->link_id);
> +	addr |= FIELD_PREP(SDW_VERSION_MASK, id->sdw_version);
> +	addr |= FIELD_PREP(SDW_UNIQUE_ID_MASK, unique_id);
> +	addr |= FIELD_PREP(SDW_MFG_ID_MASK, id->mfg_id);
> +	addr |= FIELD_PREP(SDW_PART_ID_MASK, id->part_id);
> +	addr |= FIELD_PREP(SDW_CLASS_ID_MASK, id->class_id);
> +
> +	return addr;
> +}
> +
> +static void sdw_dump_bus_peripherals(struct seq_file *s_file, struct sdw_bus *bus)
> +{
> +	struct sdw_slave *slave;
> +	u64 addr;
> +
> +	seq_printf(s_file, "master-%d-%d\n",
> +		   bus->controller_id, bus->link_id);
> +	seq_printf(s_file, SDW_PERIPH_HEADER_FMT,
> +		   "name", "dev_num", "addr", "mfg_id", "part_id",
> +		   "class_id", "unique_id", "sdw_version");
> +
> +	mutex_lock(&bus->bus_lock);
> +	list_for_each_entry(slave, &bus->slaves, node) {
> +		addr = sdw_slave_addr_from_id(bus, &slave->id);
> +		seq_printf(s_file, SDW_PERIPH_ENTRY_FMT,
> +			   dev_name(&slave->dev), slave->dev_num,
> +			   addr,
> +			   slave->id.mfg_id, slave->id.part_id,
> +			   slave->id.class_id, slave->id.unique_id,
> +			   slave->id.sdw_version);
> +	}
> +	mutex_unlock(&bus->bus_lock);
> +
> +	seq_putc(s_file, '\n');
> +}
> +
> +static int sdw_root_peripherals_dump(struct device *dev, void *data)
> +{
> +	struct sdw_master_device *md;
> +	struct seq_file *s_file = data;
> +
> +	if (dev->type != &sdw_master_type)
> +		return 0;
> +
> +	md = dev_to_sdw_master_device(dev);
> +	sdw_dump_bus_peripherals(s_file, md->bus);
> +
> +	return 0;
> +}
> +
> +static int sdw_root_peripherals_show(struct seq_file *s_file, void *data)
> +{
> +	return bus_for_each_dev(&sdw_bus_type, NULL, s_file,
> +				sdw_root_peripherals_dump);
> +}
> +DEFINE_SHOW_ATTRIBUTE(sdw_root_peripherals);
> +
>  void sdw_bus_debugfs_init(struct sdw_bus *bus)
>  {
>  	char name[16];
> @@ -375,6 +445,8 @@ void sdw_debugfs_init(void)
>  		firmware_file = kstrdup("", GFP_KERNEL);
>  
>  	sdw_debugfs_root = debugfs_create_dir("soundwire", NULL);
> +	debugfs_create_file("peripherals", 0400, sdw_debugfs_root, NULL,
> +			    &sdw_root_peripherals_fops);
>  }
>  
>  void sdw_debugfs_exit(void)

RE: [PATCH] soundwire: debugfs: add root-level peripherals table

[Liao, Bard]

> -----Original Message-----
> From: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>
> Sent: Friday, September 4, 2026 3:35 PM
> To: Bard Liao <yung-chuan.liao@linux.intel.com>; linux-
> sound@vger.kernel.org; vkoul@kernel.org
> Cc: vinod.koul@linaro.org; linux-kernel@vger.kernel.org;
> peter.ujfalusi@linux.intel.com; Liao, Bard <bard.liao@intel.com>
> Subject: Re: [PATCH] soundwire: debugfs: add root-level peripherals table
> 
> On 9/2/26 10:18, Bard Liao wrote:
> > The table will let user know what peripherals are listed and get the
> > detected status by the dev_num.
> 
> This sounds useful indeed, but does this need to be in debugfs?
> 
> We already have a sysfs entry for every peripheral listed in ACPI. Each
> peripheral will have a set of properties extracted from DisCo tables,
> could we piggy-back on all this and just expose the dev_num?

It is convenient for the user to get all information on top of the
soundwire folder instead of looking for the information one by one
in each peripheral folder.

> 
> >
> > Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>

Re: [PATCH] soundwire: debugfs: add root-level peripherals table

[Charles Keepax]

On Fri, Sep 04, 2026 at 09:35:15AM +0200, Pierre-Louis Bossart wrote:
> On 9/2/26 10:18, Bard Liao wrote:
> > The table will let user know what peripherals are listed and get the
> > detected status by the dev_num.
> 
> This sounds useful indeed, but does this need to be in debugfs?
> 
> We already have a sysfs entry for every peripheral listed in ACPI. Each
> peripheral will have a set of properties extracted from DisCo tables,
> could we piggy-back on all this and just expose the dev_num?
> 

The dev_num is already exposed through sysfs, so I think this is
more of a see everything in one place kinda deal. Although I
guess one could just make a script that pulled all the sysfs
stuff together?

Thanks,
Charles

Re: [PATCH] soundwire: debugfs: add root-level peripherals table

[Pierre-Louis Bossart]

On 9/4/26 13:36, Liao, Bard wrote:
> 
> 
>> -----Original Message-----
>> From: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>
>> Sent: Friday, September 4, 2026 3:35 PM
>> To: Bard Liao <yung-chuan.liao@linux.intel.com>; linux-
>> sound@vger.kernel.org; vkoul@kernel.org
>> Cc: vinod.koul@linaro.org; linux-kernel@vger.kernel.org;
>> peter.ujfalusi@linux.intel.com; Liao, Bard <bard.liao@intel.com>
>> Subject: Re: [PATCH] soundwire: debugfs: add root-level peripherals table
>>
>> On 9/2/26 10:18, Bard Liao wrote:
>>> The table will let user know what peripherals are listed and get the
>>> detected status by the dev_num.
>>
>> This sounds useful indeed, but does this need to be in debugfs?
>>
>> We already have a sysfs entry for every peripheral listed in ACPI. Each
>> peripheral will have a set of properties extracted from DisCo tables,
>> could we piggy-back on all this and just expose the dev_num?
> 
> It is convenient for the user to get all information on top of the
> soundwire folder instead of looking for the information one by one
> in each peripheral folder.
Right, but as Charles suggested one could use a script to provide the
information in a more self-explanatory format.
That script could even be added to 'alsa-info' and make existing reports
better without needing kernel changes.