rpmsg: Add driver_override device attribute for rpmsg_device (39e47767) · Commits · 戴 / test

Documentation/ABI/testing/sysfs-bus-rpmsg

+20 −0

Original line number	Diff line number	Diff line
		@@ -73,3 +73,23 @@ Description:
		This sysfs entry tells us whether the channel is a local
		server channel that is announced (values are either
		true or false).

		What: /sys/bus/rpmsg/devices/.../driver_override
		Date: April 2018
		KernelVersion: 4.18
		Contact: Bjorn Andersson <bjorn.andersson@linaro.org>
		Description:
		Every rpmsg device is a communication channel with a remote
		processor. Channels are identified by a textual name (see
		/sys/bus/rpmsg/devices/.../name above) and have a local
		("source") rpmsg address, and remote ("destination") rpmsg
		address.

		The listening entity (or client) which communicates with a
		remote processor is referred as rpmsg driver. The rpmsg device
		and rpmsg driver are matched based on rpmsg device name and
		rpmsg driver ID table.

		This sysfs entry allows the rpmsg driver for a rpmsg device
		to be specified which will override standard OF, ID table
		and name matching.

+39 −0

Original line number	Diff line number	Diff line
		@@ -333,11 +333,49 @@ field##_show(struct device *dev, \
		} \
		static DEVICE_ATTR_RO(field);

		#define rpmsg_string_attr(field, member) \
		static ssize_t \
		field##_store(struct device dev, struct device_attribute attr, \
		const char *buf, size_t sz) \
		{ \
		struct rpmsg_device *rpdev = to_rpmsg_device(dev); \
		char new, old; \
		\
		new = kstrndup(buf, sz, GFP_KERNEL); \
		if (!new) \
		return -ENOMEM; \
		new[strcspn(new, "\n")] = '\0'; \
		\
		device_lock(dev); \
		old = rpdev->member; \
		if (strlen(new)) { \
		rpdev->member = new; \
		} else { \
		kfree(new); \
		rpdev->member = NULL; \
		} \
		device_unlock(dev); \
		\
		kfree(old); \
		\
		return sz; \
		} \
		static ssize_t \
		field##_show(struct device *dev, \
		struct device_attribute attr, char buf) \
		{ \
		struct rpmsg_device *rpdev = to_rpmsg_device(dev); \
		\
		return sprintf(buf, "%s\n", rpdev->member); \
		} \
		static DEVICE_ATTR_RW(field)

		/* for more info, see Documentation/ABI/testing/sysfs-bus-rpmsg */
		rpmsg_show_attr(name, id.name, "%s\n");
		rpmsg_show_attr(src, src, "0x%x\n");
		rpmsg_show_attr(dst, dst, "0x%x\n");
		rpmsg_show_attr(announce, announce ? "true" : "false", "%s\n");
		rpmsg_string_attr(driver_override, driver_override);

		static ssize_t modalias_show(struct device *dev,
		struct device_attribute attr, char buf)
		@@ -359,6 +397,7 @@ static struct attribute *rpmsg_dev_attrs[] = {
		&dev_attr_dst.attr,
		&dev_attr_src.attr,
		&dev_attr_announce.attr,
		&dev_attr_driver_override.attr,
		NULL,
		};
		ATTRIBUTE_GROUPS(rpmsg_dev);