usb: gadget: f_fs: add poll for endpoint 0
This patch adds poll function for file representing ep0.
Ability of read from or write to ep0 file is related with actual state of ffs:
- When desctiptors or strings are not written yet, POLLOUT flag is set.
- If there is any event to read, POLLIN flag is set.
- If setup request was read, POLLIN and POLLOUT flag is set, to allow
send response (by performing I/O operation consistent with setup request
direction) or set stall (by performing I/O operation opposite setup
request direction).
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c
index b65a502..2032163 100644
--- a/drivers/usb/gadget/f_fs.c
+++ b/drivers/usb/gadget/f_fs.c
@@ -28,6 +28,8 @@
#include <linux/usb/composite.h>
#include <linux/usb/functionfs.h>
+#include <linux/poll.h>
+
#include "u_fs.h"
#include "configfs.h"
@@ -570,6 +572,45 @@
return ret;
}
+static unsigned int ffs_ep0_poll(struct file *file, poll_table *wait)
+{
+ struct ffs_data *ffs = file->private_data;
+ unsigned int mask = POLLWRNORM;
+ int ret;
+
+ poll_wait(file, &ffs->ev.waitq, wait);
+
+ ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
+ if (unlikely(ret < 0))
+ return mask;
+
+ switch (ffs->state) {
+ case FFS_READ_DESCRIPTORS:
+ case FFS_READ_STRINGS:
+ mask |= POLLOUT;
+ break;
+
+ case FFS_ACTIVE:
+ switch (ffs->setup_state) {
+ case FFS_NO_SETUP:
+ if (ffs->ev.count)
+ mask |= POLLIN;
+ break;
+
+ case FFS_SETUP_PENDING:
+ case FFS_SETUP_CANCELLED:
+ mask |= (POLLIN | POLLOUT);
+ break;
+ }
+ case FFS_CLOSING:
+ break;
+ }
+
+ mutex_unlock(&ffs->mutex);
+
+ return mask;
+}
+
static const struct file_operations ffs_ep0_operations = {
.llseek = no_llseek,
@@ -578,6 +619,7 @@
.read = ffs_ep0_read,
.release = ffs_ep0_release,
.unlocked_ioctl = ffs_ep0_ioctl,
+ .poll = ffs_ep0_poll,
};