greybus: hd/es2: add cport_quiesce callback and ARPC

Add a host-device cport_quiesce callback, which will be called as part
of the new connection tear-down sequence to disable flow control after
first making sure that enough peer buffer space is available for the
next messages about to be sent.

Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Sandeep Patil <sspatil@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

diff --git a/drivers/staging/greybus/arpc.h b/drivers/staging/greybus/arpc.h
index 8a90271..9fb1608 100644 (file)
--- a/drivers/staging/greybus/arpc.h
+++ b/drivers/staging/greybus/arpc.h
@@ -78,6 +78,7 @@ struct arpc_response_message {
 /* ARPC requests */
 #define ARPC_TYPE_CPORT_RESET                  0x00
 #define ARPC_TYPE_CPORT_CONNECTED              0x01
+#define ARPC_TYPE_CPORT_QUIESCE                        0x02
 
 struct arpc_cport_reset_req {
        __le16 cport_id;
@@ -87,5 +88,11 @@ struct arpc_cport_connected_req {
        __le16 cport_id;
 } __packed;
 
+struct arpc_cport_quiesce_req {
+       __le16 cport_id;
+       __le16 peer_space;
+       __le16 timeout;
+} __packed;
+
 
 #endif /* __ARPC_H */

diff --git a/drivers/staging/greybus/es2.c b/drivers/staging/greybus/es2.c
index 9af9b73..42f2483 100644 (file)
--- a/drivers/staging/greybus/es2.c
+++ b/drivers/staging/greybus/es2.c
@@ -765,6 +765,35 @@ static int es2_cport_connected(struct gb_host_device *hd, u16 cport_id)
        return 0;
 }
 
+static int es2_cport_quiesce(struct gb_host_device *hd, u16 cport_id,
+                               size_t peer_space, unsigned int timeout)
+{
+       struct es2_ap_dev *es2 = hd_to_es2(hd);
+       struct device *dev = &es2->usb_dev->dev;
+       struct arpc_cport_quiesce_req req;
+       int result;
+       int ret;
+
+       if (peer_space > U16_MAX)
+               return -EINVAL;
+
+       if (timeout > U16_MAX)
+               return -EINVAL;
+
+       req.cport_id = cpu_to_le16(cport_id);
+       req.peer_space = cpu_to_le16(peer_space);
+       req.timeout = cpu_to_le16(timeout);
+       ret = arpc_sync(es2, ARPC_TYPE_CPORT_QUIESCE, &req, sizeof(req),
+                       &result, ES2_ARPC_CPORT_TIMEOUT + timeout);
+       if (ret) {
+               dev_err(dev, "failed to quiesce cport %u: %d (%d)\n",
+                               cport_id, ret, result);
+               return ret;
+       }
+
+       return 0;
+}
+
 static int latency_tag_enable(struct gb_host_device *hd, u16 cport_id)
 {
        int retval;
@@ -950,6 +979,7 @@ static struct gb_hd_driver es2_driver = {
        .cport_enable                   = cport_enable,
        .cport_disable                  = cport_disable,
        .cport_connected                = es2_cport_connected,
+       .cport_quiesce                  = es2_cport_quiesce,
        .latency_tag_enable             = latency_tag_enable,
        .latency_tag_disable            = latency_tag_disable,
        .output                         = output,

diff --git a/drivers/staging/greybus/hd.h b/drivers/staging/greybus/hd.h
index be81879..feaba01 100644 (file)
--- a/drivers/staging/greybus/hd.h
+++ b/drivers/staging/greybus/hd.h
@@ -25,6 +25,8 @@ struct gb_hd_driver {
        int (*cport_connected)(struct gb_host_device *hd, u16 cport_id);
        int (*cport_flush)(struct gb_host_device *hd, u16 cport_id);
        int (*cport_ping)(struct gb_host_device *hd, u16 cport_id);
+       int (*cport_quiesce)(struct gb_host_device *hd, u16 cport_id,
+                               size_t peer_space, unsigned int timeout);
        int (*message_send)(struct gb_host_device *hd, u16 dest_cport_id,
                        struct gb_message *message, gfp_t gfp_mask);
        void (*message_cancel)(struct gb_message *message);