rpmsg: Add driver_override device attribute for rpmsg_device

[platform/kernel/linux-starfive.git] / drivers / rpmsg / rpmsg_core.c

diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c
index 920a02f..bea7c74 100644 (file)
--- a/drivers/rpmsg/rpmsg_core.c
+++ b/drivers/rpmsg/rpmsg_core.c
@@ -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);