/* KSDK Ethernet Driver
 *
 *  Copyright (c) 2016 ARM Ltd
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/* The driver performs one shot PHY setup.  There is no support for
 * PHY disconnect, reconnect or configuration change.  The PHY setup,
 * implemented via KSDK contains polled code that can block the
 * initialization thread for a few seconds.
 *
 * There is no statistics collection for either normal operation or
 * error behaviour.
 */

#include <board.h>
#include <device.h>
#include <misc/util.h>
#include <nanokernel.h>
#include <net/ip/net_driver_ethernet.h>

#include "fsl_enet.h"
#include "fsl_phy.h"
#include "fsl_port.h"

#define SYS_LOG_DOMAIN "ETH KSDK"
#define SYS_LOG_LEVEL CONFIG_SYS_LOG_ETHERNET_LEVEL
#include <misc/sys_log.h>

struct eth_context {
	enet_handle_t enet_handle;
	struct nano_sem tx_buf_sem;
	uint8_t mac_addr[6];
};

static int eth_net_tx(struct net_buf *);
static void eth_0_config_func(void);

static enet_rx_bd_struct_t __aligned(ENET_BUFF_ALIGNMENT)
rx_buffer_desc[CONFIG_ETH_KSDK_TX_BUFFERS];

static enet_tx_bd_struct_t __aligned(ENET_BUFF_ALIGNMENT)
tx_buffer_desc[CONFIG_ETH_KSDK_TX_BUFFERS];

/* Use ENET_FRAME_MAX_VALNFRAMELEN for VLAN frame size
 * Use ENET_FRAME_MAX_FRAMELEN for ethernet frame size
 */
#define ETH_KSDK_BUFFER_SIZE \
	ROUND_UP(ENET_FRAME_MAX_VALNFRAMELEN, ENET_BUFF_ALIGNMENT)

static uint8_t __aligned(ENET_BUFF_ALIGNMENT)
rx_buffer[CONFIG_ETH_KSDK_RX_BUFFERS][ETH_KSDK_BUFFER_SIZE];

static uint8_t __aligned(ENET_BUFF_ALIGNMENT)
tx_buffer[CONFIG_ETH_KSDK_TX_BUFFERS][ETH_KSDK_BUFFER_SIZE];

static int eth_tx(struct device *iface, struct net_buf *buf)
{
	struct eth_context *context = iface->driver_data;
	status_t status;

	nano_sem_take(&context->tx_buf_sem, TICKS_UNLIMITED);

	status = ENET_SendFrame(ENET, &context->enet_handle, uip_buf(buf),
				uip_len(buf));
	if (status) {
		SYS_LOG_ERR("ENET_SendFrame error: %d\n", status);
		return 0;
	}
	return 1;
}

static void eth_rx(struct device *iface)
{
	struct eth_context *context = iface->driver_data;
	struct net_buf *buf;
	uint32_t frame_length = 0;
	status_t status;

	status = ENET_GetRxFrameSize(&context->enet_handle, &frame_length);
	if (status) {
		enet_data_error_stats_t error_stats;

		SYS_LOG_ERR("ENET_GetRxFrameSize return: %d", status);

		ENET_GetRxErrBeforeReadFrame(&context->enet_handle,
					     &error_stats);
		/* Flush the current read buffer.  This operation can
		 * only report failure if there is no frame to flush,
		 * which cannot happen in this context.
		 */
		status = ENET_ReadFrame(ENET, &context->enet_handle, NULL, 0);
		assert(status == kStatus_Success);
		return;
	}

	buf = ip_buf_get_reserve_rx(0);
	if (buf == NULL) {
		/* We failed to get a receive buffer.  We don't add
		 * any further logging here because the allocator
		 * issued a diagnostic when it failed to allocate.
		 *
		 * Flush the current read buffer.  This operation can
		 * only report failure if there is no frame to flush,
		 * which cannot happen in this context.
		 */
		status = ENET_ReadFrame(ENET, &context->enet_handle, NULL, 0);
		assert(status == kStatus_Success);
		return;
	}

	if (net_buf_tailroom(buf) < frame_length) {
		SYS_LOG_ERR("frame too large\n");
		net_buf_unref(buf);
		status = ENET_ReadFrame(ENET, &context->enet_handle, NULL, 0);
		assert(status == kStatus_Success);
		return;
	}

	status = ENET_ReadFrame(ENET, &context->enet_handle,
				net_buf_add(buf, frame_length), frame_length);
	if (status) {
		SYS_LOG_ERR("ENET_ReadFrame failed: %d\n", status);
		net_buf_unref(buf);
		return;
	}

	uip_len(buf) = frame_length;
	net_driver_ethernet_recv(buf);
}

static void eth_callback(ENET_Type *base, enet_handle_t *handle,
			 enet_event_t event, void *param)
{
	struct device *iface = param;
	struct eth_context *context = iface->driver_data;

	switch (event) {
	case kENET_RxEvent:
		eth_rx(iface);
		break;
	case kENET_TxEvent:
		/* Free the TX buffer. */
		nano_sem_give(&context->tx_buf_sem);
		break;
	case kENET_ErrEvent:
		/* Error event: BABR/BABT/EBERR/LC/RL/UN/PLR.  */
		break;
	case kENET_WakeUpEvent:
		/* Wake up from sleep mode event. */
		break;
#ifdef ENET_ENHANCEDBUFFERDESCRIPTOR_MODE
	case kENET_TimeStampEvent:
		/* Time stamp event.  */
		break;
	case kENET_TimeStampAvailEvent:
		/* Time stamp available event.  */
		break;
#endif
	}
}

#if defined(CONFIG_ETH_KSDK_0_RANDOM_MAC)
static void generate_mac(uint8_t *mac_addr)
{
	uint32_t entropy;

	entropy = sys_rand32_get();

	/* Locally administered, unicast */
	mac_addr[0] = ((entropy >> 0) & 0xfc) | 0x02;

	mac_addr[1] = entropy >> 8;
	mac_addr[2] = entropy >> 16;
	mac_addr[3] = entropy >> 24;

	entropy = sys_rand32_get();

	mac_addr[4] = entropy >> 0;
	mac_addr[5] = entropy >> 8;
}
#endif

static int eth_0_init(struct device *dev)
{
	struct eth_context *context = dev->driver_data;
	enet_config_t enet_config;
	uint32_t sys_clock;
	const uint32_t phy_addr = 0x0;
	bool link;
	status_t status;
	int result;
	enet_buffer_config_t buffer_config = {
		.rxBdNumber = CONFIG_ETH_KSDK_RX_BUFFERS,
		.txBdNumber = CONFIG_ETH_KSDK_TX_BUFFERS,
		.rxBuffSizeAlign = ETH_KSDK_BUFFER_SIZE,
		.txBuffSizeAlign = ETH_KSDK_BUFFER_SIZE,
		.rxBdStartAddrAlign = rx_buffer_desc,
		.txBdStartAddrAlign = tx_buffer_desc,
		.rxBufferAlign = rx_buffer[0],
		.txBufferAlign = tx_buffer[0],
	};

	nano_sem_init(&context->tx_buf_sem);
	for (int i = 0; i < CONFIG_ETH_KSDK_TX_BUFFERS; i++) {
		nano_sem_give(&context->tx_buf_sem);
	}

	sys_clock = CLOCK_GetFreq(kCLOCK_CoreSysClk);

	ENET_GetDefaultConfig(&enet_config);
	enet_config.interrupt |= kENET_RxFrameInterrupt;
	enet_config.interrupt |= kENET_TxFrameInterrupt;

	status = PHY_Init(ENET, phy_addr, sys_clock);
	if (status) {
		SYS_LOG_ERR("PHY_Init() failed: %d", status);
		return 1;
	}

	PHY_GetLinkStatus(ENET, phy_addr, &link);
	if (link) {
		phy_speed_t phy_speed;
		phy_duplex_t phy_duplex;

		PHY_GetLinkSpeedDuplex(ENET, phy_addr, &phy_speed, &phy_duplex);
		enet_config.miiSpeed = (enet_mii_speed_t) phy_speed;
		enet_config.miiDuplex = (enet_mii_duplex_t) phy_duplex;

		SYS_LOG_INF("Enabled %dM %s-duplex mode.",
			    (phy_speed ? 100 : 10),
			    (phy_duplex ? "full" : "half"));
	} else {
		SYS_LOG_INF("Link down.");
	}

#if defined(CONFIG_ETH_KSDK_0_RANDOM_MAC)
	generate_mac(context->mac_addr);
#endif

	ENET_Init(ENET,
		  &context->enet_handle,
		  &enet_config,
		  &buffer_config,
		  context->mac_addr,
		  sys_clock);

	SYS_LOG_DBG("MAC %2.2x:%2.2x:%2.2x:%2.2x:%2.2x:%2.2x",
		    context->mac_addr[0], context->mac_addr[1],
		    context->mac_addr[2], context->mac_addr[3],
		    context->mac_addr[4], context->mac_addr[5]);

	result = net_set_mac(context->mac_addr, sizeof(context->mac_addr));
	if (result) {
		return 1;
	}

	ENET_SetCallback(&context->enet_handle, eth_callback, dev);
	net_driver_ethernet_register_tx(eth_net_tx);
	eth_0_config_func();
	ENET_ActiveRead(ENET);
	return 0;
}

static void eth_ksdk_rx_isr(void *p)
{
	struct device *dev = p;
	struct eth_context *context = dev->driver_data;

	ENET_ReceiveIRQHandler(ENET, &context->enet_handle);
}

static void eth_ksdk_tx_isr(void *p)
{
	struct device *dev = p;
	struct eth_context *context = dev->driver_data;

	ENET_TransmitIRQHandler(ENET, &context->enet_handle);
}

static void eth_ksdk_error_isr(void *p)
{
	struct device *dev = p;
	struct eth_context *context = dev->driver_data;

	ENET_ErrorIRQHandler(ENET, &context->enet_handle);
}

static struct eth_context eth_0_context = {
#if !defined(CONFIG_ETH_KSDK_0_RANDOM_MAC)
	.mac_addr = {
		CONFIG_ETH_KSDK_0_MAC0,
		CONFIG_ETH_KSDK_0_MAC1,
		CONFIG_ETH_KSDK_0_MAC2,
		CONFIG_ETH_KSDK_0_MAC3,
		CONFIG_ETH_KSDK_0_MAC4,
		CONFIG_ETH_KSDK_0_MAC5
	}
#endif
};

DEVICE_INIT(eth_ksdk_0, CONFIG_ETH_KSDK_0_NAME, eth_0_init,
	    &eth_0_context, NULL,
	    NANOKERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE);

static int eth_net_tx(struct net_buf *buf)
{
	return eth_tx(DEVICE_GET(eth_ksdk_0), buf);
}

static void eth_0_config_func(void)
{
	IRQ_CONNECT(IRQ_ETH_RX, CONFIG_ETH_KSDK_0_IRQ_PRI,
		    eth_ksdk_rx_isr, DEVICE_GET(eth_ksdk_0), 0);
	irq_enable(IRQ_ETH_RX);

	IRQ_CONNECT(IRQ_ETH_TX, CONFIG_ETH_KSDK_0_IRQ_PRI,
		    eth_ksdk_tx_isr, DEVICE_GET(eth_ksdk_0), 0);
	irq_enable(IRQ_ETH_TX);

	IRQ_CONNECT(IRQ_ETH_ERR_MISC, CONFIG_ETH_KSDK_0_IRQ_PRI,
		    eth_ksdk_error_isr, DEVICE_GET(eth_ksdk_0), 0);
	irq_enable(IRQ_ETH_ERR_MISC);
}