drivers: usb: mcux: Fix the write operation

1. Do not copy over the data to the local buffer,
it can be directly sent to the controller. The
cache is flushed before calling the HAL send
function. Also do not allocate a buffer from
the heap pool for the write operation.
2. Remove a length check as this is handled by
the HAL driver.

Signed-off-by: Mahesh Mahadevan <[email protected]>

Author: mmahadevan108

drivers/usb/device/usb_dc_mcux.c

@@ -241,7 +241,6 @@ int usb_dc_ep_configure(const struct usb_dc_ep_cfg_data *const cfg)
 {
 	uint8_t ep_abs_idx =  EP_ABS_IDX(cfg->ep_addr);
 	usb_device_endpoint_init_struct_t ep_init;
-	struct k_mem_block *block;
 	struct usb_ep_ctrl_data *eps = &dev_state.eps[ep_abs_idx];
 	usb_status_t status;
 	uint8_t ep;
@@ -269,19 +268,25 @@ int usb_dc_ep_configure(const struct usb_dc_ep_cfg_data *const cfg)
 		LOG_WRN("Failed to un-initialize endpoint (status=%d)", (int)status);
 	}
 
-	block = &(eps->block);
-	if (block->data) {
-		k_heap_free(&ep_buf_pool, block->data);
-		block->data = NULL;
-	}
+	/* Allocate buffers used during read operation */
+	if (USB_EP_DIR_IS_OUT(cfg->ep_addr)) {
+		struct k_mem_block *block;
+
+		block = &(eps->block);
+		if (block->data) {
+			k_heap_free(&ep_buf_pool, block->data);
+			block->data = NULL;
+		}
 
-	block->data = k_heap_alloc(&ep_buf_pool, cfg->ep_mps, K_NO_WAIT);
-	if (block->data == NULL) {
-		LOG_ERR("Failed to allocate memory");
-		return -ENOMEM;
+		block->data = k_heap_alloc(&ep_buf_pool, cfg->ep_mps, K_NO_WAIT);
+		if (block->data == NULL) {
+			LOG_ERR("Failed to allocate memory");
+			return -ENOMEM;
+		}
+
+		memset(block->data, 0, cfg->ep_mps);
 	}
 
-	memset(block->data, 0, cfg->ep_mps);
 	dev_state.eps[ep_abs_idx].ep_mps = cfg->ep_mps;
 	status = dev_state.dev_struct.controllerInterface->deviceControl(
 			dev_state.dev_struct.controllerHandle,
@@ -486,8 +491,6 @@ int usb_dc_ep_write(const uint8_t ep, const uint8_t *const data,
 		    const uint32_t data_len, uint32_t *const ret_bytes)
 {
 	uint8_t ep_abs_idx = EP_ABS_IDX(ep);
-	uint8_t *buffer = (uint8_t *)dev_state.eps[ep_abs_idx].block.data;
-	uint32_t len_to_send;
 	usb_status_t status;
 
 	if (ep_abs_idx >= NUM_OF_EP_MAX) {
@@ -500,29 +503,19 @@ int usb_dc_ep_write(const uint8_t ep, const uint8_t *const data,
 		return -EINVAL;
 	}
 
-	if (data_len > dev_state.eps[ep_abs_idx].ep_mps) {
-		len_to_send = dev_state.eps[ep_abs_idx].ep_mps;
-	} else {
-		len_to_send = data_len;
-	}
-
-	for (uint32_t n = 0; n < len_to_send; n++) {
-		buffer[n] = data[n];
-	}
-
-#if defined(CONFIG_HAS_MCUX_CACHE) && !defined(EP_BUF_NONCACHED)
-	DCACHE_CleanByRange((uint32_t)buffer, len_to_send);
+#if defined(CONFIG_HAS_MCUX_CACHE)
+	DCACHE_CleanByRange((uint32_t)data, data_len);
 #endif
 	status = dev_state.dev_struct.controllerInterface->deviceSend(
 						dev_state.dev_struct.controllerHandle,
-						ep, buffer, len_to_send);
+						ep, (uint8_t *)data, data_len);
 	if (kStatus_USB_Success != status) {
 		LOG_ERR("Failed to fill ep 0x%02x buffer", ep);
 		return -EIO;
 	}
 
 	if (ret_bytes) {
-		*ret_bytes = len_to_send;
+		*ret_bytes = data_len;
 	}
 
 	return 0;