greybus: es2: Add a new bulk in endpoint for APBridgeA RPC

Add a new bulk in endpoint in order to get RPC status
from APbridgeA without to have to poll on control endpoint.

So the new endpoint layout is:
EP0: control EP
EP1 and EP2: muxed endpoints (bulk in and out)
EP3 to EP14: direct muxed endpoints (bulk in and out)
EP15: ARPC bulk in endpoint

Note:
This patch is allocating ARPC URBs but does nothing with them.
The following patch will use them.

Testing Done:
  Tested with an APBridgeA enumerating 16 endpoints.
  Kernel doesn't print Not enough endpoints found in device, aborting!

Signed-off-by: Alexandre Bailon <abailon@baylibre.com>
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Alex Elder <elder@linaro.org>

diff --git a/drivers/staging/greybus/es2.c b/drivers/staging/greybus/es2.c
index 5bdf2e1..8ebbd70 100644 (file)
--- a/drivers/staging/greybus/es2.c
+++ b/drivers/staging/greybus/es2.c
@@ -25,6 +25,9 @@
 /* Memory sizes for the buffers sent to/from the ES2 controller */
 #define ES2_GBUF_MSG_SIZE_MAX  2048
 
+/* Memory sizes for the ARPC buffers */
+#define ARPC_IN_SIZE_MAX       128
+
 static const struct usb_device_id id_table[] = {
        { USB_DEVICE(0x18d1, 0x1eaf) },
        { },
@@ -36,6 +39,12 @@ MODULE_DEVICE_TABLE(usb, id_table);
 /* Number of bulk in and bulk out couple */
 #define NUM_BULKS              7
 
+/* Expected number of bulk out endpoints */
+#define NUM_BULKS_OUT          NUM_BULKS
+
+/* Expected number of bulk in endpoints (including ARPC endpoint) */
+#define NUM_BULKS_IN           (NUM_BULKS + 1)
+
 /*
  * Number of CPort IN urbs in flight at any point in time.
  * Adjust if we are having stalls in the USB buffer due to not enough urbs in
@@ -49,6 +58,11 @@ MODULE_DEVICE_TABLE(usb, id_table);
 #define NUM_CPORT_OUT_URB      (8 * NUM_BULKS)
 
 /*
+ * Number of ARPC in urbs in flight at any point in time.
+ */
+#define NUM_ARPC_IN_URB                2
+
+/*
  * @endpoint: bulk in endpoint for CPort data
  * @urb: array of urbs for the CPort in messages
  * @buffer: array of buffers for the @cport_in_urb urbs
@@ -85,6 +99,9 @@ struct es2_cport_out {
  * @apb_log_dentry: file system entry for the log file interface
  * @apb_log_enable_dentry: file system entry for enabling logging
  * @apb_log_fifo: kernel FIFO to carry logged data
+ * @arpc_urb: array of urbs for the ARPC in messages
+ * @arpc_buffer: array of buffers for the @arpc_urb urbs
+ * @arpc_endpoint_in: bulk in endpoint for APBridgeA RPC
  */
 struct es2_ap_dev {
        struct usb_device *usb_dev;
@@ -106,6 +123,10 @@ struct es2_ap_dev {
        struct dentry *apb_log_dentry;
        struct dentry *apb_log_enable_dentry;
        DECLARE_KFIFO(apb_log_fifo, char, APB1_LOG_SIZE);
+
+       __u8 arpc_endpoint_in;
+       struct urb *arpc_urb[NUM_ARPC_IN_URB];
+       u8 *arpc_buffer[NUM_ARPC_IN_URB];
 };
 
 /**
@@ -344,6 +365,45 @@ static void es2_cport_in_disable(struct es2_ap_dev *es2,
        }
 }
 
+static int es2_arpc_in_enable(struct es2_ap_dev *es2)
+{
+       struct urb *urb;
+       int ret;
+       int i;
+
+       for (i = 0; i < NUM_ARPC_IN_URB; ++i) {
+               urb = es2->arpc_urb[i];
+
+               ret = usb_submit_urb(urb, GFP_KERNEL);
+               if (ret) {
+                       dev_err(&es2->usb_dev->dev,
+                               "failed to submit arpc in-urb: %d\n", ret);
+                       goto err_kill_urbs;
+               }
+       }
+
+       return 0;
+
+err_kill_urbs:
+       for (--i; i >= 0; --i) {
+               urb = es2->arpc_urb[i];
+               usb_kill_urb(urb);
+       }
+
+       return ret;
+}
+
+static void es2_arpc_in_disable(struct es2_ap_dev *es2)
+{
+       struct urb *urb;
+       int i;
+
+       for (i = 0; i < NUM_ARPC_IN_URB; ++i) {
+               urb = es2->arpc_urb[i];
+               usb_kill_urb(urb);
+       }
+}
+
 static struct urb *next_free_urb(struct es2_ap_dev *es2, gfp_t gfp_mask)
 {
        struct urb *urb = NULL;
@@ -899,6 +959,16 @@ static void es2_destroy(struct es2_ap_dev *es2)
                es2->cport_out_urb_busy[i] = false;     /* just to be anal */
        }
 
+       for (i = 0; i < NUM_ARPC_IN_URB; ++i) {
+               struct urb *urb = es2->arpc_urb[i];
+
+               if (!urb)
+                       break;
+               usb_free_urb(urb);
+               kfree(es2->arpc_buffer[i]);
+               es2->arpc_buffer[i] = NULL;
+       }
+
        for (bulk_in = 0; bulk_in < NUM_BULKS; bulk_in++) {
                struct es2_cport_in *cport_in = &es2->cport_in[bulk_in];
 
@@ -991,6 +1061,31 @@ static void cport_out_callback(struct urb *urb)
        free_urb(es2, urb);
 }
 
+static void arpc_in_callback(struct urb *urb)
+{
+       struct device *dev = &urb->dev->dev;
+       int status = check_urb_status(urb);
+       int retval;
+
+       if (status) {
+               if ((status == -EAGAIN) || (status == -EPROTO))
+                       goto exit;
+
+               /* The urb is being unlinked */
+               if (status == -ENOENT || status == -ESHUTDOWN)
+                       return;
+
+               dev_err(dev, "arpc in-urb error %d (dropped)\n", status);
+               return;
+       }
+
+exit:
+       /* put our urb back in the request pool */
+       retval = usb_submit_urb(urb, GFP_ATOMIC);
+       if (retval)
+               dev_err(dev, "failed to resubmit arpc in-urb: %d\n", retval);
+}
+
 #define APB1_LOG_MSG_SIZE      64
 static void apb_log_get(struct es2_ap_dev *es2, char *buf)
 {
@@ -1225,8 +1320,13 @@ static int ap_probe(struct usb_interface *interface,
                endpoint = &iface_desc->endpoint[i].desc;
 
                if (usb_endpoint_is_bulk_in(endpoint)) {
-                       es2->cport_in[bulk_in++].endpoint =
-                               endpoint->bEndpointAddress;
+                       if (bulk_in < NUM_BULKS)
+                               es2->cport_in[bulk_in].endpoint =
+                                       endpoint->bEndpointAddress;
+                       else
+                               es2->arpc_endpoint_in =
+                                       endpoint->bEndpointAddress;
+                       bulk_in++;
                } else if (usb_endpoint_is_bulk_out(endpoint)) {
                        es2->cport_out[bulk_out++].endpoint =
                                endpoint->bEndpointAddress;
@@ -1236,7 +1336,7 @@ static int ap_probe(struct usb_interface *interface,
                                endpoint->bEndpointAddress);
                }
        }
-       if (bulk_in != NUM_BULKS || bulk_out != NUM_BULKS) {
+       if (bulk_in != NUM_BULKS_IN || bulk_out != NUM_BULKS_OUT) {
                dev_err(&udev->dev, "Not enough endpoints found in device, aborting!\n");
                retval = -ENODEV;
                goto error;
@@ -1271,6 +1371,32 @@ static int ap_probe(struct usb_interface *interface,
                }
        }
 
+       /* Allocate buffers for ARPC in messages */
+       for (i = 0; i < NUM_ARPC_IN_URB; ++i) {
+               struct urb *urb;
+               u8 *buffer;
+
+               urb = usb_alloc_urb(0, GFP_KERNEL);
+               if (!urb) {
+                       retval = -ENOMEM;
+                       goto error;
+               }
+               buffer = kmalloc(ARPC_IN_SIZE_MAX, GFP_KERNEL);
+               if (!buffer) {
+                       retval = -ENOMEM;
+                       goto error;
+               }
+
+               usb_fill_bulk_urb(urb, udev,
+                                 usb_rcvbulkpipe(udev,
+                                                 es2->arpc_endpoint_in),
+                                 buffer, ARPC_IN_SIZE_MAX,
+                                 arpc_in_callback, es2);
+
+               es2->arpc_urb[i] = urb;
+               es2->arpc_buffer[i] = buffer;
+       }
+
        /* Allocate urbs for our CPort OUT messages */
        for (i = 0; i < NUM_CPORT_OUT_URB; ++i) {
                struct urb *urb;
@@ -1291,9 +1417,12 @@ static int ap_probe(struct usb_interface *interface,
                                                        gb_debugfs_get(), es2,
                                                        &apb_log_enable_fops);
 
+       if (es2_arpc_in_enable(es2))
+               goto error;
+
        retval = gb_hd_add(hd);
        if (retval)
-               goto error;
+               goto err_disable_arpc_in;
 
        for (i = 0; i < NUM_BULKS; ++i) {
                retval = es2_cport_in_enable(es2, &es2->cport_in[i]);
@@ -1307,6 +1436,8 @@ err_disable_cport_in:
        for (--i; i >= 0; --i)
                es2_cport_in_disable(es2, &es2->cport_in[i]);
        gb_hd_del(hd);
+err_disable_arpc_in:
+       es2_arpc_in_disable(es2);
 error:
        es2_destroy(es2);
 
@@ -1322,6 +1453,7 @@ static void ap_disconnect(struct usb_interface *interface)
 
        for (i = 0; i < NUM_BULKS; ++i)
                es2_cport_in_disable(es2, &es2->cport_in[i]);
+       es2_arpc_in_disable(es2);
 
        es2_destroy(es2);
 }