drivers: nxp_enet: Remove unnecessary comments

Some comments in this driver are just redundant - the code
spells out exactly what the comment says. And some comment
blocks are just unnecessary to have. Finally, remove the TODO
comment because this is flagged by static analysis and there
are already tracking issues for the zero copy enhancement.

Signed-off-by: Declan Snyder <[email protected]>

Author: decsny

drivers/ethernet/eth_nxp_enet.c

@@ -2,7 +2,7 @@
  *
  * Copyright 2023 NXP
  *
- * Inspiration from eth_mcux.c, which is:
+ * Inspiration from eth_mcux.c, which was:
  *  Copyright (c) 2016-2017 ARM Ltd
  *  Copyright (c) 2016 Linaro Ltd
  *  Copyright (c) 2018 Intel Corporation
@@ -19,47 +19,35 @@
 #include <zephyr/logging/log.h>
 LOG_MODULE_REGISTER(LOG_MODULE_NAME);
 
-/*
- ************
- * Includes *
- ************
- */
-
 #include <zephyr/device.h>
 #include <zephyr/sys/util.h>
 #include <zephyr/kernel.h>
 #include <zephyr/sys/__assert.h>
+
 #include <zephyr/net/net_pkt.h>
 #include <zephyr/net/net_if.h>
 #include <zephyr/net/ethernet.h>
+#include <zephyr/net/phy.h>
+#include <zephyr/net/mii.h>
 #include <ethernet/eth_stats.h>
+
 #include <zephyr/drivers/pinctrl.h>
 #include <zephyr/drivers/clock_control.h>
-#include <zephyr/drivers/ethernet/eth_nxp_enet.h>
-#include <zephyr/dt-bindings/ethernet/nxp_enet.h>
-#include <zephyr/net/phy.h>
-#include <zephyr/net/mii.h>
+
+#ifdef CONFIG_PTP_CLOCK
 #include <zephyr/drivers/ptp_clock.h>
-#if defined(CONFIG_NET_DSA)
-#include <zephyr/net/dsa.h>
 #endif
 
-#include "fsl_enet.h"
+#ifdef CONFIG_NET_DSA
+#include <zephyr/net/dsa.h>
+#endif
 
-/*
- ***********
- * Defines *
- ***********
- */
+#include <zephyr/drivers/ethernet/eth_nxp_enet.h>
+#include <zephyr/dt-bindings/ethernet/nxp_enet.h>
+#include <fsl_enet.h>
 
 #define RING_ID 0
 
-/*
- *********************
- * Driver Structures *
- *********************
- */
-
 struct nxp_enet_mac_config {
 	ENET_Type *base;
 	const struct device *clock_dev;
@@ -92,31 +80,10 @@ struct nxp_enet_mac_data {
 	struct k_sem ptp_ts_sem;
 	struct k_mutex *ptp_mutex; /* created in PTP driver */
 #endif
-	/* TODO: FIXME. This Ethernet frame sized buffer is used for
-	 * interfacing with MCUX. How it works is that hardware uses
-	 * DMA scatter buffers to receive a frame, and then public
-	 * MCUX call gathers them into this buffer (there's no other
-	 * public interface). All this happens only for this driver
-	 * to scatter this buffer again into Zephyr fragment buffers.
-	 * This is not efficient, but proper resolution of this issue
-	 * depends on introduction of zero-copy networking support
-	 * in Zephyr, and adding needed interface to MCUX (or
-	 * bypassing it and writing a more complex driver working
-	 * directly with hardware).
-	 *
-	 * Note that we do not copy FCS into this buffer thus the
-	 * size is 1514 bytes.
-	 */
-	uint8_t *tx_frame_buf; /* Max MTU + ethernet header */
-	uint8_t *rx_frame_buf; /* Max MTU + ethernet header */
+	uint8_t *tx_frame_buf;
+	uint8_t *rx_frame_buf;
 };
 
-/*
- ********************
- * Helper Functions *
- ********************
- */
-
 static inline struct net_if *get_iface(struct nxp_enet_mac_data *data)
 {
 	return data->iface;
@@ -187,12 +154,6 @@ static const struct device *eth_nxp_enet_get_ptp_clock(const struct device *dev)
 }
 #endif /* CONFIG_PTP_CLOCK */
 
-/*
- *********************************
- * Ethernet driver API Functions *
- *********************************
- */
-
 static int eth_nxp_enet_tx(const struct device *dev, struct net_pkt *pkt)
 {
 	const struct nxp_enet_mac_config *config = dev->config;
@@ -207,7 +168,6 @@ static int eth_nxp_enet_tx(const struct device *dev, struct net_pkt *pkt)
 	/* Enter critical section for TX frame buffer access */
 	k_mutex_lock(&data->tx_frame_buf_mutex, K_FOREVER);
 
-	/* Read network packet from upper layer into frame buffer */
 	ret = net_pkt_read(pkt, data->tx_frame_buf, total_len);
 	if (ret) {
 		k_sem_give(&data->tx_buf_sem);
@@ -321,12 +281,6 @@ static int eth_nxp_enet_set_config(const struct device *dev,
 	return -ENOTSUP;
 }
 
-/*
- *****************************
- * Ethernet RX Functionality *
- *****************************
- */
-
 static int eth_nxp_enet_rx(const struct device *dev)
 {
 	const struct nxp_enet_mac_config *config = dev->config;
@@ -447,12 +401,6 @@ static void eth_nxp_enet_rx_thread(void *arg1, void *unused1, void *unused2)
 	}
 }
 
-/*
- ****************************
- * PHY management functions *
- ****************************
- */
-
 static int nxp_enet_phy_reset_and_configure(const struct device *phy)
 {
 	int ret;
@@ -511,12 +459,6 @@ static int nxp_enet_phy_init(const struct device *dev)
 	return ret;
 }
 
-/*
- ****************************
- * Callbacks and interrupts *
- ****************************
- */
-
 void nxp_enet_driver_cb(const struct device *dev, enum nxp_enet_driver dev_type,
 				enum nxp_enet_callback_reason event, void *data)
 {
@@ -599,12 +541,6 @@ static void eth_nxp_enet_isr(const struct device *dev)
 	irq_unlock(irq_lock_key);
 }
 
-/*
- ******************
- * Initialization *
- ******************
- */
-
 static int eth_nxp_enet_init(const struct device *dev)
 {
 	struct nxp_enet_mac_data *data = dev->data;
@@ -618,7 +554,6 @@ static int eth_nxp_enet_init(const struct device *dev)
 		return err;
 	}
 
-	/* Initialize kernel objects */
 	k_mutex_init(&data->rx_frame_buf_mutex);
 	k_mutex_init(&data->tx_frame_buf_mutex);
 	k_sem_init(&data->rx_thread_sem, 0, CONFIG_ETH_NXP_ENET_RX_BUFFERS);
@@ -640,14 +575,12 @@ static int eth_nxp_enet_init(const struct device *dev)
 			0, K_NO_WAIT);
 	k_thread_name_set(&data->rx_thread, "eth_nxp_enet_rx");
 
-	/* Get ENET IP module clock rate */
 	err = clock_control_get_rate(config->clock_dev, config->clock_subsys,
 			&enet_module_clock_rate);
 	if (err) {
 		return err;
 	}
 
-	/* Use HAL to set up MAC configuration */
 	ENET_GetDefaultConfig(&enet_config);
 
 	if (IS_ENABLED(CONFIG_NET_PROMISCUOUS_MODE)) {
@@ -930,9 +863,6 @@ static const struct ethernet_api api_funcs = {
 
 DT_INST_FOREACH_STATUS_OKAY(NXP_ENET_MAC_INIT)
 
-/*
- * ENET module-level management
- */
 #undef DT_DRV_COMPAT
 #define DT_DRV_COMPAT nxp_enet