Allow creating and deleting devices via sysfs. Devices created will be
matched to serdev drivers via modalias (the string provided by the user)
and deleted via their name. Eg:
# Create device
root@qt5022:~# echo ttydev > /sys/bus/serial/devices/serial0/new_device
# Delete device
root@qt5022:~#
echo serial0-0 > /sys/bus/serial/devices/serial0/delete_device
Cc: Rob Herring <r...@kernel.org>
Cc: Johan Hovold <jo...@kernel.org>
Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
Cc: Jiri Slaby <jsl...@suse.com>
Cc: Andy Shevchenko <andy.shevche...@gmail.com>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.riba...@gmail.com>
---
drivers/tty/serdev/core.c | 69 +++++++++++++++++++++++++++++++++++++++
1 file changed, 69 insertions(+)
diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
index 2c79f47fc0db..5df01d8cf307 100644
--- a/drivers/tty/serdev/core.c
+++ b/drivers/tty/serdev/core.c
@@ -75,7 +75,76 @@ static void serdev_ctrl_release(struct device *dev)
kfree(ctrl);
}
+static ssize_t
+new_device_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct serdev_controller *ctrl = to_serdev_controller(dev);
+ struct serdev_device *serdev;
+ char *nline;
+ int len;
+ int err;
+
+ serdev = serdev_device_alloc(ctrl);
+ if (!serdev)
+ return -ENOMEM;
+
+ nline = strchr(buf, '\n');
+ if (nline)
+ len = nline - buf;
+ else
+ len = strlen(buf);
+ len = min(SERDEV_NAME_SIZE - 1, len);
+
+ strncpy(serdev->modalias, buf, len);
+ serdev->modalias[len] = '\0';
+
+ err = serdev_device_add(serdev);
+ if (err) {
+ serdev_device_put(serdev);
+ return err;
+ }
+
+ return count;
+}
+static DEVICE_ATTR_WO(new_device);
+
+static ssize_t
+delete_device_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct serdev_controller *ctrl = to_serdev_controller(dev);
+ struct serdev_device *serdev = ctrl->serdev;
+ char *nline;
+ int len;
+
+ nline = strchr(buf, '\n');
+ if (nline)
+ len = nline - buf;
+ else
+ len = strlen(buf);
+ len = min(SERDEV_NAME_SIZE - 1, len);
+
+ if (!ctrl->serdev ||
+ strncmp(dev_name(&serdev->dev), buf, len))
+ return -ENODEV;
+
+ serdev_device_remove(serdev);
+
+ return count;
+}
+static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, 0200, NULL,
+ delete_device_store);
+
+static struct attribute *serdev_ctrl_attrs[] = {
+ &dev_attr_new_device.attr,
+ &dev_attr_delete_device.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(serdev_ctrl);
+
static const struct device_type serdev_ctrl_type = {
+ .groups = serdev_ctrl_groups,
.release = serdev_ctrl_release,
};
--
2.17.1
