drivers: usb: udc: stm32: allow EP max packet size up to HW capabilities

The maximal packet size (for non-control endpoints) was obtained by the
driver from HAL definitions which appear to not properly reflect hardware
capabilities.

Update driver to allow endpoints with wMaxPacketSize up to the maximal
value allowed by the USB Specification depending on operation mode, since
all STM32 USB controllers always support these values. Also move the EP
max packet size field in the 'struct udc_stm32_config' to avoid implicit
padding and add a documentation comment.

Signed-off-by: Mathieu Choplain <[email protected]>

Author: mathieuchopstm

drivers/usb/udc/udc_stm32.c

@@ -121,6 +121,17 @@ LOG_MODULE_REGISTER(udc_stm32, CONFIG_UDC_DRIVER_LOG_LEVEL);
 		(PCD_SPEED_HIGH_IN_FULL),				\
 		(PCD_SPEED_HIGH))))
 
+/*
+ * Returns max packet size allowed for endpoints of 'usb_node'
+ *
+ * Hardware always supports the maximal value allowed
+ * by the USB Specification at a given operating speed:
+ * 1024 bytes in High-Speed, 1023 bytes in Full-Speed
+ */
+#define UDC_STM32_NODE_EP_MPS(node_id)					\
+	((UDC_STM32_NODE_SPEED(node_id) == PCD_SPEED_HIGH) ? 1024U : 1023U)
+
+
 #if DT_HAS_COMPAT_STATUS_OKAY(st_stm32n6_otghs)
 #define USB_USBPHYC_CR_FSEL_24MHZ        USB_USBPHYC_CR_FSEL_1
 #endif
@@ -158,11 +169,12 @@ struct udc_stm32_data  {
 struct udc_stm32_config {
 	uint32_t num_endpoints;
 	uint32_t dram_size;
-	uint16_t ep_mps;
 	/* PHY selected for use by instance */
 	uint32_t selected_phy;
 	/* Speed selected for use by instance */
 	uint32_t selected_speed;
+	/* Maximal packet size allowed for endpoints */
+	uint16_t ep_mps;
 };
 
 enum udc_stm32_msg_type {
@@ -1070,18 +1082,7 @@ static const struct udc_api udc_stm32_api = {
  * Kconfig system.
  */
 #define USB_NUM_BIDIR_ENDPOINTS	DT_INST_PROP(0, num_bidir_endpoints)
-
-#if defined(USB) || defined(USB_DRD_FS)
-#define EP_MPS 64U
-#define USB_RAM_SIZE	DT_INST_PROP(0, ram_size)
-#else /* USB_OTG_FS */
-#if DT_HAS_COMPAT_STATUS_OKAY(st_stm32_otghs)
-#define EP_MPS USB_OTG_HS_MAX_PACKET_SIZE
-#elif DT_HAS_COMPAT_STATUS_OKAY(st_stm32_otgfs) || DT_HAS_COMPAT_STATUS_OKAY(st_stm32_usb)
-#define EP_MPS USB_OTG_FS_MAX_PACKET_SIZE
-#endif
-#define USB_RAM_SIZE	DT_INST_PROP(0, ram_size)
-#endif /* USB */
+#define USB_RAM_SIZE		DT_INST_PROP(0, ram_size)
 
 static struct udc_stm32_data udc0_priv;
 
@@ -1093,7 +1094,7 @@ static struct udc_data udc0_data = {
 static const struct udc_stm32_config udc0_cfg  = {
 	.num_endpoints = USB_NUM_BIDIR_ENDPOINTS,
 	.dram_size = USB_RAM_SIZE,
-	.ep_mps = EP_MPS,
+	.ep_mps = UDC_STM32_NODE_EP_MPS(DT_DRV_INST(0)),
 	.selected_phy = UDC_STM32_NODE_PHY_ITFACE(DT_DRV_INST(0)),
 	.selected_speed = UDC_STM32_NODE_SPEED(DT_DRV_INST(0)),
 };