Changeset 6271a34 in mainline for uspace/lib/usbhost/src/utility.c

Timestamp:

2018-01-20T18:21:39Z (8 years ago)

Author:

Jenda <jenda.jzqk73@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

2aaba7e

Parents:

51c1d500

Message:

handle HS/SS max_packet_size

File:

• uspace/lib/usbhost/src/utility.c (modified) (2 diffs)

uspace/lib/usbhost/src/utility.c

@@ -42 +42 @@
 #include "utility.h"
 
-
-/**
- * Get max packet size for the control endpoint 0.
- *
- * For LS, HS, and SS devices this value is fixed. For FS devices we must fetch
- * the first 8B of the device descriptor to determine it.
- *
- * @return Max packet size for EP 0
- */
-int hc_get_ep0_max_packet_size(uint16_t *mps, bus_t *bus, device_t *dev)
-{
-        assert(mps);
-
+/**
+ * Get initial max packet size for the control endpoint 0.
+ *
+ * For LS, HS, and SS devices this value is final and fixed.
+ * For FS devices, the default value of 8 is returned. The caller needs
+ * to fetch the first 8B of the device descriptor later in the initialization
+ * process and determine whether it should be increased.
+ *
+ * @return Max packet size for EP 0 (in bytes)
+ */
+uint16_t hc_get_ep0_initial_mps(usb_speed_t speed)
+{
         static const uint16_t mps_fixed [] = {
                 [USB_SPEED_LOW] = 8,
@@ -61 +60 @@
         };
 
-        if (dev->speed < ARRAY_SIZE(mps_fixed) && mps_fixed[dev->speed] != 0) {
-                *mps = mps_fixed[dev->speed];
+        if (speed < ARRAY_SIZE(mps_fixed) && mps_fixed[speed] != 0) {
+                return mps_fixed[speed];
+        }
+        return 8; // USB_SPEED_FULL default
+}
+
+/**
+ * Get max packet size for the control endpoint 0.
+ *
+ * For LS, HS, and SS devices the corresponding fixed value is obtained.
+ * For FS devices the first 8B of the device descriptor are fetched to
+ * determine it.
+ *
+ * @return Max packet size for EP 0 (in bytes)
+ */
+int hc_get_ep0_max_packet_size(uint16_t *mps, bus_t *bus, device_t *dev)
+{
+        assert(mps);
+
+        *mps = hc_get_ep0_initial_mps(dev->speed);
+        if (dev->speed != USB_SPEED_FULL) {
                 return EOK;
         }