Thread (84 messages) 84 messages, 11 authors, 2022-11-17

Re: [RFC PATCH 2/2] driver core: add compatible string in sysfs for platform devices

From: Greg KH <gregkh@linuxfoundation.org>
Date: 2022-08-03 12:32:01
Also in: lkml

On Wed, Aug 03, 2022 at 05:56:55PM +0530, Nipun Gupta wrote:
quoted hunk ↗ jump to hunk
For devices registered dynamically using platform_device_register
API, this patch exposes the sysfs entry for the compatible string.

Signed-off-by: Nipun Gupta <nipun.gupta@amd.com>
---
 drivers/base/platform.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 51bb2289865c..89949f88a0a1 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -1289,10 +1289,25 @@ static ssize_t driver_override_store(struct device *dev,
 }
 static DEVICE_ATTR_RW(driver_override);
 
+static ssize_t compatible_show(struct device *dev, struct device_attribute *attr,
+			      char *buf)
+{
+	const char *compat;
+	int ret;
+
+	ret = device_property_read_string(dev, "compatible", &compat);
+	if (ret != 0)
+		return 0;
+
+	return sysfs_emit(buf, "%s", compat);
+}
+static DEVICE_ATTR_RO(compatible);
You forgot the Documentation/ABI/ update :(

Also, what happens if there is no such string to read?  Why are you
returning 0?  You should not create the attribute at all then, right?

thanks,

greg k-h

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