greybus: es2: get cport count from apb1 usb device
Use the control request REQUEST_CPORT_COUNT in order to get the number of
CPorts supported by the UniPro IP.
Signed-off-by: Fabien Parent <fparent@baylibre.com>
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
diff --git a/drivers/staging/greybus/es2.c b/drivers/staging/greybus/es2.c
index 909ca6a..13605b8 100644
--- a/drivers/staging/greybus/es2.c
+++ b/drivers/staging/greybus/es2.c
@@ -33,9 +33,6 @@
static struct task_struct *apb1_log_task;
static DEFINE_KFIFO(apb1_log_fifo, char, APB1_LOG_SIZE);
-/* Number of cport present on USB bridge */
-#define CPORT_COUNT 44
-
/* Number of bulk in and bulk out couple */
#define NUM_BULKS 7
@@ -60,6 +57,9 @@
/* vendor request to map a cport to bulk in and bulk out endpoints */
#define REQUEST_EP_MAPPING 0x03
+/* vendor request to get the number of cports available */
+#define REQUEST_CPORT_COUNT 0x04
+
/*
* @endpoint: bulk in endpoint for CPort data
* @urb: array of urbs for the CPort in messages
@@ -636,6 +636,39 @@
.write = apb1_log_enable_write,
};
+static int apb1_get_cport_count(struct usb_device *udev)
+{
+ int retval;
+ __le16 *cport_count;
+
+ cport_count = kmalloc(sizeof(*cport_count), GFP_KERNEL);
+ if (!cport_count)
+ return -ENOMEM;
+
+ retval = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
+ REQUEST_CPORT_COUNT,
+ USB_DIR_IN | USB_TYPE_VENDOR |
+ USB_RECIP_INTERFACE, 0, 0, cport_count,
+ sizeof(*cport_count), ES1_TIMEOUT);
+ if (retval < 0) {
+ dev_err(&udev->dev, "Cannot retrieve CPort count: %d\n",
+ retval);
+ goto out;
+ }
+
+ retval = le16_to_cpu(*cport_count);
+
+ /* We need to fit a CPort ID in one byte of a message header */
+ if (retval > U8_MAX) {
+ retval = U8_MAX;
+ dev_warn(&udev->dev, "Limiting number of CPorts to U8_MAX\n");
+ }
+
+out:
+ kfree(cport_count);
+ return retval;
+}
+
/*
* The ES1 USB Bridge device contains 4 endpoints
* 1 Control - usual USB stuff + AP -> SVC messages
@@ -655,14 +688,20 @@
int bulk_out = 0;
int retval = -ENOMEM;
int i;
-
- /* We need to fit a CPort ID in one byte of a message header */
- BUILD_BUG_ON(CPORT_ID_MAX > U8_MAX);
+ int num_cports;
udev = usb_get_dev(interface_to_usbdev(interface));
+ num_cports = apb1_get_cport_count(udev);
+ if (num_cports < 0) {
+ usb_put_dev(udev);
+ dev_err(&udev->dev, "Cannot retrieve CPort count: %d\n",
+ num_cports);
+ return num_cports;
+ }
+
hd = greybus_create_hd(&es1_driver, &udev->dev, ES1_GBUF_MSG_SIZE_MAX,
- CPORT_COUNT);
+ num_cports);
if (IS_ERR(hd)) {
usb_put_dev(udev);
return PTR_ERR(hd);
