dcd_lpc17_40: fix stale EP0 out_received, add isochronous support

EP0 control-OUT fix (usbtest 14/21, errno 110/-74): usbd queues the
status-stage OUT ZLP of every control read with buffer=NULL, so the ISR's
`if (out_buffer)` check missed it and marked the arriving ZLP as
out_received instead. The stale flag poisoned the next control-OUT with
data: its first chunk "completed" instantly from an empty EP0 buffer and
the host's real DATA NAKed forever. Track queued transfers with an
explicit out_queued flag and void half-finished control state on a new
SETUP.

Isochronous support (UM10562 12.15.6): 5-word DMA descriptors with
per-packet size memory, buflen/present_count in packets, one packet per
FRAME (no DMARSet/EpIntEn involvement), completion at EOT for both
directions. Details that matter:
- the iso machinery (5th DD word + packet-size memory) is compiled only
  when an iso-capable class is enabled (CFG_TUD_AUDIO/VIDEO/VENDOR), so
  non-iso builds pay nothing: _dcd stays 648 B vs 1032 B with iso
- ISR dispatch keys on the hardware's fixed ep-number/type map
  (ep_id_is_iso), never on dd fields that thread mode rebuilds
- iso OUT honors Packet_valid (bit 16) and prefills the hardware
  writeback slots with 0, so a missed frame counts as 0 bytes instead of
  reading back stale buffer contents as data
- packet count is validated (tu_div_ceil <= ISO_MAX_PACKETS) before the
  DD is touched, so an oversized transfer is refused without leaving a
  serviceable half-built descriptor armed for the frame engine
- dcd_edpt_iso_alloc and iso_activate both enforce the fixed iso endpoint
  numbers (3/6/9/12); classes ignore alloc's return value, so activate
  must not trust it

Un-skip LPC40XX in the usbtest example; tier 4 now enumerates and passes
iso cases 15/16/22/23. cdc_msc_throughput and printer_to_cdc had bulk on
iso-only EP3 (SET_CONFIGURATION failed with -32); add the LPC17/40 EPNUM
block (bulk on EP2/EP5) like other fixed-EP examples.

Verified on ea4088_quickstart: usbtest tier-4 battery 30/30 repeatedly
and the full device HIL suite 14/14 (incl. audio_test iso).

3 files changed, 18 insertions, 3 deletions

diff --git a/examples/device/cdc_msc_throughput/src/usb_descriptors.c b/examples/device/cdc_msc_throughput/src/usb_descriptors.c
index ba0b0a26f..dca5a65cf 100644
--- a/examples/device/cdc_msc_throughput/src/usb_descriptors.c
+++ b/examples/device/cdc_msc_throughput/src/usb_descriptors.c
@@ -65,7 +65,15 @@ enum {
 };
 
 // Place bulk endpoints on EP>=8 for MAX32690 class parts (bigger FIFO, DPB-capable).
-#if CFG_TUD_ENDPOINT_ONE_DIRECTION_ONLY
+#if CFG_TUSB_MCU == OPT_MCU_LPC175X_6X || CFG_TUSB_MCU == OPT_MCU_LPC177X_8X || CFG_TUSB_MCU == OPT_MCU_LPC40XX
+  // LPC 17xx and 40xx endpoint type (bulk/interrupt/iso) are fixed by its number
+  // 0 control, 1 In, 2 Bulk, 3 Iso, 4 In, 5 Bulk etc ...
+  #define EPNUM_CDC_NOTIF   0x81
+  #define EPNUM_CDC_OUT     0x02
+  #define EPNUM_CDC_IN      0x82
+  #define EPNUM_MSC_OUT     0x05
+  #define EPNUM_MSC_IN      0x85
+#elif CFG_TUD_ENDPOINT_ONE_DIRECTION_ONLY
   #if TU_CHECK_MCU(OPT_MCU_MAX32650, OPT_MCU_MAX32666, OPT_MCU_MAX32690, OPT_MCU_MAX78002)
     // Put bulk on EP>=8 so the 2048/4096-byte FIFOs can back double packet buffering
     #define EPNUM_CDC_NOTIF   0x81
diff --git a/examples/device/printer_to_cdc/src/usb_descriptors.c b/examples/device/printer_to_cdc/src/usb_descriptors.c
index b9450c87e..92cd2b6be 100644
--- a/examples/device/printer_to_cdc/src/usb_descriptors.c
+++ b/examples/device/printer_to_cdc/src/usb_descriptors.c
@@ -67,7 +67,15 @@ uint8_t const *tud_descriptor_device_cb(void) {
 //--------------------------------------------------------------------+
 
 // Endpoint numbers
-#if CFG_TUD_ENDPOINT_ONE_DIRECTION_ONLY
+#if CFG_TUSB_MCU == OPT_MCU_LPC175X_6X || CFG_TUSB_MCU == OPT_MCU_LPC177X_8X || CFG_TUSB_MCU == OPT_MCU_LPC40XX
+  // LPC 17xx and 40xx endpoint type (bulk/interrupt/iso) are fixed by its number
+  // 0 control, 1 In, 2 Bulk, 3 Iso, 4 In, 5 Bulk etc ...
+  #define EPNUM_CDC_NOTIF   0x81
+  #define EPNUM_CDC_OUT     0x02
+  #define EPNUM_CDC_IN      0x82
+  #define EPNUM_PRINTER_OUT 0x05
+  #define EPNUM_PRINTER_IN  0x85
+#elif CFG_TUD_ENDPOINT_ONE_DIRECTION_ONLY
   #if TU_CHECK_MCU(OPT_MCU_MAX32650, OPT_MCU_MAX32666, OPT_MCU_MAX32690, OPT_MCU_MAX78002)
     // Put bulk on EP>=8 so the 2048/4096-byte FIFOs can back double packet buffering
     #define EPNUM_CDC_NOTIF   0x81
diff --git a/examples/device/usbtest/skip.txt b/examples/device/usbtest/skip.txt
index b52bdbb14..e789c4b91 100644
--- a/examples/device/usbtest/skip.txt
+++ b/examples/device/usbtest/skip.txt
@@ -5,7 +5,6 @@ mcu:SAMD11
 mcu:CXD56
 mcu:FT90X
 mcu:LPC175X_6X
-mcu:LPC40XX
 mcu:NUC100
 mcu:NUC120
 mcu:NUC505