/* ieee802154_cc2520_yaip.c - YAIP version of TI CC2520 driver */

/*
 * Copyright (c) 2016 Intel Corporation.
 *
 * 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.
 */

#define SYS_LOG_LEVEL CONFIG_SYS_LOG_TI_CC2520_LEVEL
#define SYS_LOG_NO_NEWLINE
#include <misc/sys_log.h>

#include <errno.h>

#include <nanokernel.h>
#include <arch/cpu.h>

#include <board.h>
#include <device.h>
#include <init.h>
#include <net/net_if.h>
#include <net/nbuf.h>

#include <misc/byteorder.h>
#include <string.h>
#include <rand32.h>

#include <gpio.h>

#include <net/ieee802154_radio.h>

#include "ieee802154_cc2520.h"

/**
 * Content is split as follows:
 * 1 - Debug related functions
 * 2 - Generic helper functions (for any parts)
 * 3 - GPIO related functions
 * 4 - TX related helper functions
 * 5 - RX related helper functions
 * 6 - Radio device API functions
 * 7 - Legacy radio device API functions
 * 8 - Initialization
 */


#if defined(CONFIG_TI_CC2520_AUTO_CRC) && defined(CONFIG_TI_CC2520_AUTO_ACK)
#define CC2520_AUTOMATISM		(FRMCTRL0_AUTOCRC | FRMCTRL0_AUTOACK)
#elif defined(CONFIG_TI_CC2520_AUTO_CRC)
#define CC2520_AUTOMATISM		(FRMCTRL0_AUTOCRC)
#else
#define CC2520_AUTOMATISM		(0)
#endif

#define CC2520_TX_THRESHOLD		(0x7F)
#define CC2520_FCS_LENGTH		(2)

/*********
 * DEBUG *
 ********/
#ifndef CONFIG_TI_CC2520_DEBUG
#define _cc2520_print_gpio_config(...)
#define _cc2520_print_exceptions(...)
#define _cc2520_print_errors(...)
#else
static inline void _cc2520_print_gpio_config(struct device *dev)
{
	struct cc2520_context *cc2520 = dev->driver_data;

	SYS_LOG_DBG(" GPIOCTRL0/1/2/3/4/5 = 0x%x/0x%x/0x%x/0x%x/0x%x/0x%x\n",
	    read_reg_gpioctrl0(&cc2520->spi),
	    read_reg_gpioctrl1(&cc2520->spi),
	    read_reg_gpioctrl2(&cc2520->spi),
	    read_reg_gpioctrl3(&cc2520->spi),
	    read_reg_gpioctrl4(&cc2520->spi),
	    read_reg_gpioctrl5(&cc2520->spi));
	SYS_LOG_DBG(" GPIOPOLARITY: 0x%x\n",
	    read_reg_gpiopolarity(&cc2520->spi));
	SYS_LOG_DBG(" GPIOCTRL: 0x%x\n",
	    read_reg_gpioctrl(&cc2520->spi));
}

static inline void _cc2520_print_exceptions(struct cc2520_context *cc2520)
{
	uint8_t flag = read_reg_excflag0(&cc2520->spi);

	SYS_LOG_DBG(" EXCFLAG0: ");
	if (flag & EXCFLAG0_RF_IDLE) {
		SYS_LOG_DBG("RF_IDLE ");
	}
	if (flag & EXCFLAG0_TX_FRM_DONE) {
		SYS_LOG_DBG("TX_FRM_DONE ");
	}
	if (flag & EXCFLAG0_TX_ACK_DONE) {
		SYS_LOG_DBG("TX_ACK_DONE ");
	}
	if (flag & EXCFLAG0_TX_UNDERFLOW) {
		SYS_LOG_DBG("TX_UNDERFLOW ");
	}
	if (flag & EXCFLAG0_TX_OVERFLOW) {
		SYS_LOG_DBG("TX_OVERFLOW ");
	}
	if (flag & EXCFLAG0_RX_UNDERFLOW) {
		SYS_LOG_DBG("RX_UNDERFLOW ");
	}
	if (flag & EXCFLAG0_RX_OVERFLOW) {
		SYS_LOG_DBG("RX_OVERFLOW ");
	}
	if (flag & EXCFLAG0_RXENABLE_ZERO) {
		SYS_LOG_DBG("RXENABLE_ZERO");
	}
	SYS_LOG_DBG("\n");

	flag = read_reg_excflag1(&cc2520->spi);

	SYS_LOG_DBG(" EXCFLAG1: ");
	if (flag & EXCFLAG1_RX_FRM_DONE) {
		SYS_LOG_DBG("RX_FRM_DONE ");
	}
	if (flag & EXCFLAG1_RX_FRM_ACCEPTED) {
		SYS_LOG_DBG("RX_FRM_ACCEPTED ");
	}
	if (flag & EXCFLAG1_SRC_MATCH_DONE) {
		SYS_LOG_DBG("SRC_MATCH_DONE ");
	}
	if (flag & EXCFLAG1_SRC_MATCH_FOUND) {
		SYS_LOG_DBG("SRC_MATCH_FOUND ");
	}
	if (flag & EXCFLAG1_FIFOP) {
		SYS_LOG_DBG("FIFOP ");
	}
	if (flag & EXCFLAG1_SFD) {
		SYS_LOG_DBG("SFD ");
	}
	if (flag & EXCFLAG1_DPU_DONE_L) {
		SYS_LOG_DBG("DPU_DONE_L ");
	}
	if (flag & EXCFLAG1_DPU_DONE_H) {
		SYS_LOG_DBG("DPU_DONE_H");
	}
	SYS_LOG_DBG("\n");
}

static inline void _cc2520_print_errors(struct cc2520_context *cc2520)
{
	uint8_t flag = read_reg_excflag2(&cc2520->spi);

	SYS_LOG_DBG("EXCFLAG2: ");
	if (flag & EXCFLAG2_MEMADDR_ERROR) {
		SYS_LOG_DBG("MEMADDR_ERROR ");
	}
	if (flag & EXCFLAG2_USAGE_ERROR) {
		SYS_LOG_DBG("USAGE_ERROR ");
	}
	if (flag & EXCFLAG2_OPERAND_ERROR) {
		SYS_LOG_DBG("OPERAND_ERROR ");
	}
	if (flag & EXCFLAG2_SPI_ERROR) {
		SYS_LOG_DBG("SPI_ERROR ");
	}
	if (flag & EXCFLAG2_RF_NO_LOCK) {
		SYS_LOG_DBG("RF_NO_LOCK ");
	}
	if (flag & EXCFLAG2_RX_FRM_ABORTED) {
		SYS_LOG_DBG("RX_FRM_ABORTED ");
	}
	if (flag & EXCFLAG2_RFBUFMOV_TIMEOUT) {
		SYS_LOG_DBG("RFBUFMOV_TIMEOUT");
	}
	SYS_LOG_DBG("\n");
}
#endif


/*********************
 * Generic functions *
 ********************/
static void _usleep(uint32_t usec)
{
	if (sys_execution_context_type_get() == K_ISR) {
		k_busy_wait(usec);
		return;
	}

	/* k_sleep expects parameter to be in milliseconds */
	k_sleep(usec * 1000);
}

uint8_t _cc2520_read_reg(struct cc2520_spi *spi,
			 bool freg, uint8_t addr)
{
	uint8_t len = freg ? 2 : 3;

	spi->cmd_buf[0] = freg ? CC2520_INS_REGRD | addr : CC2520_INS_MEMRD;
	spi->cmd_buf[1] = freg ? 0 : addr;
	spi->cmd_buf[2] = 0;

	spi_slave_select(spi->dev, spi->slave);

	if (spi_transceive(spi->dev, spi->cmd_buf, len,
			   spi->cmd_buf, len) == 0) {
		return spi->cmd_buf[len - 1];
	}

	return 0;
}

bool _cc2520_write_reg(struct cc2520_spi *spi, bool freg,
		       uint8_t addr, uint8_t value)
{
	uint8_t len = freg ? 2 : 3;

	spi->cmd_buf[0] = freg ? CC2520_INS_REGWR | addr : CC2520_INS_MEMWR;
	spi->cmd_buf[1] = freg ? value : addr;
	spi->cmd_buf[2] = freg ? 0 : value;

	spi_slave_select(spi->dev, spi->slave);

	return (spi_write(spi->dev, spi->cmd_buf, len) == 0);
}

bool _cc2520_write_ram(struct cc2520_spi *spi, uint16_t addr,
		       uint8_t *data_buf, uint8_t len)
{
	spi->cmd_buf[0] = CC2520_INS_MEMWR | (addr >> 8);
	spi->cmd_buf[1] = addr;

	memcpy(&spi->cmd_buf[2], data_buf, len);

	spi_slave_select(spi->dev, spi->slave);

	return (spi_write(spi->dev, spi->cmd_buf, len + 2) == 0);
}

static uint8_t _cc2520_status(struct cc2520_spi *spi)
{
	spi->cmd_buf[0] = CC2520_INS_SNOP;

	spi_slave_select(spi->dev, spi->slave);

	if (spi_transceive(spi->dev, spi->cmd_buf, 1,
			   spi->cmd_buf, 1) == 0) {
		return spi->cmd_buf[0];
	}

	return 0;
}

static bool verify_osc_stabilization(struct cc2520_context *cc2520)
{
	uint8_t timeout = 100;
	uint8_t status;

	do {
		status = _cc2520_status(&cc2520->spi);
		_usleep(1);
		timeout--;
	} while (!(status & CC2520_STATUS_XOSC_STABLE_N_RUNNING) && timeout);

	return !!(status & CC2520_STATUS_XOSC_STABLE_N_RUNNING);
}


static inline uint8_t *get_mac(struct device *dev)
{
	struct cc2520_context *cc2520 = dev->driver_data;

	cc2520->mac_addr[0] = 0x00;
	cc2520->mac_addr[1] = 0x12;
	cc2520->mac_addr[2] = 0x4b;

	cc2520->mac_addr[3] = 0x00;
	UNALIGNED_PUT(sys_cpu_to_be32(sys_rand32_get()),
		      (uint32_t *) ((void *)cc2520->mac_addr+4));

	cc2520->mac_addr[7] = (cc2520->mac_addr[7] & ~0x01) | 0x02;

	return cc2520->mac_addr;
}

/******************
 * GPIO functions *
 *****************/
static inline void set_reset(struct device *dev, uint32_t value)
{
	struct cc2520_context *cc2520 = dev->driver_data;

	gpio_pin_write(cc2520->gpios[CC2520_GPIO_IDX_RESET],
		       CONFIG_CC2520_GPIO_RESET, value);
}

static inline void set_vreg_en(struct device *dev, uint32_t value)
{
	struct cc2520_context *cc2520 = dev->driver_data;

	gpio_pin_write(cc2520->gpios[CC2520_GPIO_IDX_VREG_EN],
		       CONFIG_CC2520_GPIO_VREG_EN, value);
}

static inline uint32_t get_fifo(struct cc2520_context *cc2520)
{
	uint32_t pin_value;

	gpio_pin_read(cc2520->gpios[CC2520_GPIO_IDX_FIFO],
		      CONFIG_CC2520_GPIO_FIFO, &pin_value);

	return pin_value;
}

static inline uint32_t get_fifop(struct cc2520_context *cc2520)
{
	uint32_t pin_value;

	gpio_pin_read(cc2520->gpios[CC2520_GPIO_IDX_FIFOP],
		      CONFIG_CC2520_GPIO_FIFOP, &pin_value);

	return pin_value;
}

static inline uint32_t get_cca(struct cc2520_context *cc2520)
{
	uint32_t pin_value;

	gpio_pin_read(cc2520->gpios[CC2520_GPIO_IDX_CCA],
		      CONFIG_CC2520_GPIO_CCA, &pin_value);

	return pin_value;
}

static inline void sfd_int_handler(struct device *port,
				   struct gpio_callback *cb, uint32_t pins)
{
	struct cc2520_context *cc2520 =
		CONTAINER_OF(cb, struct cc2520_context, sfd_cb);

	if (atomic_get(&cc2520->tx) == 1) {
		atomic_set(&cc2520->tx, 0);
		device_sync_call_complete(&cc2520->tx_sync);
	}
}

static inline void fifop_int_handler(struct device *port,
				     struct gpio_callback *cb, uint32_t pins)
{
	struct cc2520_context *cc2520 =
		CONTAINER_OF(cb, struct cc2520_context, fifop_cb);

	/* Note: Errata document - 1.2 */
	if (!get_fifop(cc2520) && !get_fifop(cc2520)) {
		return;
	}

	if (!get_fifo(cc2520)) {
		cc2520->overflow = true;
	}

	nano_isr_sem_give(&cc2520->rx_lock);
}

static void enable_fifop_interrupt(struct cc2520_context *cc2520,
				   bool enable)
{
	if (enable) {
		gpio_pin_enable_callback(cc2520->gpios[CC2520_GPIO_IDX_FIFOP],
					 CONFIG_CC2520_GPIO_FIFOP);
	} else {
		gpio_pin_disable_callback(cc2520->gpios[CC2520_GPIO_IDX_FIFOP],
					  CONFIG_CC2520_GPIO_FIFOP);
	}
}

static void enable_sfd_interrupt(struct cc2520_context *cc2520,
				 bool enable)
{
	if (enable) {
		gpio_pin_enable_callback(cc2520->gpios[CC2520_GPIO_IDX_SFD],
					 CONFIG_CC2520_GPIO_SFD);
	} else {
		gpio_pin_disable_callback(cc2520->gpios[CC2520_GPIO_IDX_SFD],
					  CONFIG_CC2520_GPIO_SFD);
	}
}

static inline void setup_gpio_callbacks(struct device *dev)
{
	struct cc2520_context *cc2520 = dev->driver_data;

	gpio_init_callback(&cc2520->sfd_cb,
			   sfd_int_handler, BIT(CONFIG_CC2520_GPIO_SFD));
	gpio_add_callback(cc2520->gpios[CC2520_GPIO_IDX_SFD],
			  &cc2520->sfd_cb);

	gpio_init_callback(&cc2520->fifop_cb,
			   fifop_int_handler, BIT(CONFIG_CC2520_GPIO_FIFOP));
	gpio_add_callback(cc2520->gpios[CC2520_GPIO_IDX_FIFOP],
			  &cc2520->fifop_cb);
}


/****************
 * TX functions *
 ***************/
static inline bool write_txfifo_length(struct cc2520_spi *spi,
				       struct net_buf *buf)
{
	spi->cmd_buf[0] = CC2520_INS_TXBUF;
	spi->cmd_buf[1] = net_nbuf_ll_reserve(buf) +
		net_buf_frags_len(buf) + CC2520_FCS_LENGTH;

	spi_slave_select(spi->dev, spi->slave);

	return (spi_write(spi->dev, spi->cmd_buf, 2) == 0);
}

static inline bool write_txfifo_content(struct cc2520_spi *spi,
					struct net_buf *buf)
{
	uint8_t cmd[128 + 1];

	cmd[0] = CC2520_INS_TXBUF;
	memcpy(&cmd[1], net_nbuf_ll(buf),
	       net_nbuf_ll_reserve(buf) + net_buf_frags_len(buf));

	spi_slave_select(spi->dev, spi->slave);

	return (spi_write(spi->dev, cmd, net_nbuf_ll_reserve(buf) +
			  net_buf_frags_len(buf) + 1) == 0);
}

static inline bool verify_txfifo_status(struct cc2520_context *cc2520,
					struct net_buf *buf)
{
	if (read_reg_txfifocnt(&cc2520->spi) < (net_nbuf_ll_reserve(buf) +
						net_buf_frags_len(buf)) ||
	    (read_reg_excflag0(&cc2520->spi) & EXCFLAG0_TX_UNDERFLOW)) {
		return false;
	}

	return true;
}

static inline bool verify_tx_done(struct cc2520_context *cc2520)
{
	uint8_t timeout = 10;
	uint8_t status;

	do {
		_usleep(1);
		timeout--;
		status = read_reg_excflag0(&cc2520->spi);
	} while (!(status & EXCFLAG0_TX_FRM_DONE) && timeout);

	return !!(status & EXCFLAG0_TX_FRM_DONE);
}

static inline void enable_reception(struct cc2520_context *cc2520)
{
	/* Note: Errata document - 1.1 */
	enable_fifop_interrupt(cc2520, false);

	instruct_srxon(&cc2520->spi);
	instruct_sflushrx(&cc2520->spi);
	instruct_sflushrx(&cc2520->spi);

	enable_fifop_interrupt(cc2520, true);

	write_reg_excflag0(&cc2520->spi, EXCFLAG0_RESET_RX_FLAGS);
}

/****************
 * RX functions *
 ***************/

static inline void flush_rxfifo(struct cc2520_context *cc2520)
{
	/* Note: Errata document - 1.1 */
	enable_fifop_interrupt(cc2520, false);

	instruct_sflushrx(&cc2520->spi);
	instruct_sflushrx(&cc2520->spi);

	enable_fifop_interrupt(cc2520, true);

	write_reg_excflag0(&cc2520->spi, EXCFLAG0_RESET_RX_FLAGS);
}

#ifdef CONFIG_SPI_QMSI
/** This is a workaround, for SPI QMSI drivers as current QMSI API does not
 * support asymmetric tx/rx buffer lengths.
 * (i.e.: it's up to the user to handle tx dummy bytes in tx buffer)
 */
static inline uint8_t read_rxfifo_length(struct cc2520_spi *spi)
{
	spi->cmd_buf[0] = CC2520_INS_RXBUF;
	spi->cmd_buf[1] = 0;

	spi_slave_select(spi->dev, spi->slave);

	if (spi_transceive(spi->dev, spi->cmd_buf, 2,
			   spi->cmd_buf, 2) == 0) {
		return spi->cmd_buf[1];
	}

	return 0;
}

static inline bool read_rxfifo_content(struct cc2520_spi *spi,
				       struct net_buf *buf, uint8_t len)
{
	uint8_t data[128+1];

	data[0] = CC2520_INS_RXBUF;
	memset(&data[1], 0, len);

	spi_slave_select(spi->dev, spi->slave);

	if (spi_transceive(spi->dev, data, len+1, data, len+1) != 0) {
		return false;
	}

	if (read_reg_excflag0(spi) & EXCFLAG0_RX_UNDERFLOW) {
		return false;
	}

	memcpy(buf->data, &data[1], len);
	net_buf_add(buf, len);

	return true;
}

#else /* CONFIG_SPI_QMSI */
static inline uint8_t read_rxfifo_length(struct cc2520_spi *spi)
{
	spi->cmd_buf[0] = CC2520_INS_RXBUF;

	spi_slave_select(spi->dev, spi->slave);

	if (spi_transceive(spi->dev, spi->cmd_buf, 1,
			   spi->cmd_buf, 2) == 0) {
		return spi->cmd_buf[1];
	}

	return 0;
}

static inline bool read_rxfifo_content(struct cc2520_spi *spi,
				       struct net_buf *buf, uint8_t len)
{
	uint8_t data[128+1];

	spi->cmd_buf[0] = CC2520_INS_RXBUF;

	spi_slave_select(spi->dev, spi->slave);

	if (spi_transceive(spi->dev, spi->cmd_buf, 1, data, len+1) != 0) {
		return false;
	}

	if (read_reg_excflag0(spi) & EXCFLAG0_RX_UNDERFLOW) {
		return false;
	}

	memcpy(buf->data, &data[1], len);
	net_buf_add(buf, len);

	return true;
}
#endif /* CONFIG_SPI_QMSI */

static inline bool verify_rxfifo_validity(struct cc2520_spi *spi,
					  uint8_t pkt_len)
{
	if (pkt_len < 2 || read_reg_rxfifocnt(spi) != pkt_len) {
		return false;
	}

	return true;
}

static void cc2520_rx(int arg, int unused2)
{
	struct device *dev = INT_TO_POINTER(arg);
	struct cc2520_context *cc2520 = dev->driver_data;
	struct net_buf *pkt_buf = NULL;
	struct net_buf *buf = NULL;
	uint8_t pkt_len;

	ARG_UNUSED(unused2);

	while (1) {
		nano_fiber_sem_take(&cc2520->rx_lock, TICKS_UNLIMITED);

		if (cc2520->overflow) {
			SYS_LOG_DBG("RX overflow!\n");
			cc2520->overflow = false;

			goto flush;
		}

		pkt_len = read_rxfifo_length(&cc2520->spi) & 0x7f;
		if (!verify_rxfifo_validity(&cc2520->spi, pkt_len)) {
			SYS_LOG_DBG("Invalid content\n");
			goto flush;
		}

		buf = net_nbuf_get_reserve_rx(0);
		if (!buf) {
			SYS_LOG_DBG("No buf available\n");
			goto flush;
		}

		pkt_buf = net_nbuf_get_reserve_data(0);
		if (!pkt_buf) {
			SYS_LOG_DBG("No pkt_buf available\n");
			goto out;
		}

		net_buf_frag_insert(buf, pkt_buf);

		if (!read_rxfifo_content(&cc2520->spi, pkt_buf, pkt_len)) {
			SYS_LOG_DBG("No content read\n");
			goto out;
		}

#ifdef CONFIG_TI_CC2520_AUTO_CRC
		if (!(pkt_buf->data[pkt_len - 1] & CC2520_FCS_CRC_OK)) {
			SYS_LOG_DBG("Bad packet CRC\n");
			goto out;
		}
#endif /* CONFIG_TI_CC2520_AUTO_CRC */

		if (ieee802154_radio_handle_ack(cc2520->iface, buf) == NET_OK) {
			SYS_LOG_DBG("ACK packet handled");
			goto out;
		}

		SYS_LOG_DBG("Caught a packet (%u)\n", pkt_len - CC2520_FCS_LENGTH);

		if (net_recv_data(cc2520->iface, buf) < 0) {
			SYS_LOG_DBG("Packet dropped by NET stack\n");
			goto out;
		}

		net_analyze_stack("CC2520 Rx Fiber stack",
				  (unsigned char *)cc2520->cc2520_rx_stack,
				  CONFIG_CC2520_RX_STACK_SIZE);
		goto flush;
out:
		net_buf_unref(buf);
flush:
		flush_rxfifo(cc2520);
	}
}

/********************
 * Radio device API *
 *******************/
static int cc2520_cca(struct device *dev)
{
	struct cc2520_context *cc2520 = dev->driver_data;

	if (!get_cca(cc2520)) {
		return -EBUSY;
	}

	return 0;
}

static int cc2520_set_channel(struct device *dev, uint16_t channel)
{
	struct cc2520_context *cc2520 = dev->driver_data;

	SYS_LOG_DBG(" %u\n", channel);

	if (channel < 11 || channel > 26) {
		return -EINVAL;
	}

	/* See chapter 16 */
	channel = 11 + 5 * (channel - 11);

	if (!write_reg_freqctrl(&cc2520->spi, FREQCTRL_FREQ(channel))) {
		SYS_LOG_ERR(" FAILED\n");
		return -EIO;
	}

	return 0;
}

static int cc2520_set_pan_id(struct device *dev, uint16_t pan_id)
{
	struct cc2520_context *cc2520 = dev->driver_data;

	SYS_LOG_DBG(" 0x%x\n", pan_id);

	pan_id = sys_le16_to_cpu(pan_id);

	if (!write_mem_pan_id(&cc2520->spi, (uint8_t *) &pan_id)) {
		SYS_LOG_ERR(" FAILED\n");
		return -EIO;
	}

	return 0;
}

static int cc2520_set_short_addr(struct device *dev, uint16_t short_addr)
{
	struct cc2520_context *cc2520 = dev->driver_data;

	SYS_LOG_DBG(" 0x%x\n", short_addr);

	short_addr = sys_le16_to_cpu(short_addr);

	if (!write_mem_short_addr(&cc2520->spi, (uint8_t *) &short_addr)) {
		SYS_LOG_ERR(" FAILED\n");
		return -EIO;
	}

	return 0;
}

static int cc2520_set_ieee_addr(struct device *dev, const uint8_t *ieee_addr)
{
	struct cc2520_context *cc2520 = dev->driver_data;
	uint8_t ext_addr[8];
	int idx;

	for (idx = 0; idx < 8; idx++) {
		ext_addr[idx] = ieee_addr[7 - idx];
	}

	if (!write_mem_ext_addr(&cc2520->spi, ext_addr)) {
		SYS_LOG_ERR(" FAILED\n");
		return -EIO;
	}

	SYS_LOG_DBG(" IEEE address %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
		    ieee_addr[0], ieee_addr[1], ieee_addr[2], ieee_addr[3],
		    ieee_addr[4], ieee_addr[5], ieee_addr[6], ieee_addr[7]);

	return 0;
}

static int cc2520_set_txpower(struct device *dev, int16_t dbm)
{
	struct cc2520_context *cc2520 = dev->driver_data;
	uint8_t pwr;

	SYS_LOG_DBG("%s: %d\n", dbm);

	/* See chapter 19 part 8 */
	switch (dbm) {
	case 5:
		pwr = 0xF7;
		break;
	case 3:
		pwr = 0xF2;
		break;
	case 2:
		pwr = 0xAB;
		break;
	case 1:
		pwr = 0x13;
		break;
	case 0:
		pwr = 0x32;
		break;
	case -2:
		pwr = 0x81;
		break;
	case -4:
		pwr = 0x88;
		break;
	case -7:
		pwr = 0x2C;
		break;
	case -18:
		pwr = 0x03;
		break;
	default:
		goto error;
	}

	if (!write_reg_txpower(&cc2520->spi, pwr)) {
		goto error;
	}

	return 0;
error:
	SYS_LOG_DBG("%s: FAILED\n");
	return -EIO;
}

static int cc2520_tx(struct device *dev, struct net_buf *buf)
{
	struct cc2520_context *cc2520 = dev->driver_data;
	uint8_t retry = 2;
	bool status;

	SYS_LOG_DBG("%s: %p (%u)\n", __func__,
	    buf, net_nbuf_ll_reserve(buf) + net_buf_frags_len(buf));

	if (!write_reg_excflag0(&cc2520->spi, EXCFLAG0_RESET_TX_FLAGS) ||
	    !write_txfifo_length(&cc2520->spi, buf) ||
	    !write_txfifo_content(&cc2520->spi, buf)) {
		SYS_LOG_ERR(" Cannot feed in TX fifo\n");
		goto error;
	}

	if (!verify_txfifo_status(cc2520, buf)) {
		SYS_LOG_ERR(" Did not write properly into TX FIFO\n");
		goto error;
	}

	/* 1 retry is allowed here */
	do {
		atomic_set(&cc2520->tx, 1);

		if (!instruct_stxoncca(&cc2520->spi)) {
			SYS_LOG_ERR(" Cannot start transmission\n");
			goto error;
		}

		/* _cc2520_print_exceptions(cc2520); */

		device_sync_call_wait(&cc2520->tx_sync);

		retry--;
		status = verify_tx_done(cc2520);
	} while (!status && retry);

	if (!status) {
		SYS_LOG_ERR(" No TX_FRM_DONE\n");
		goto error;
	}

	enable_reception(cc2520);

	return 0;
error:
	atomic_set(&cc2520->tx, 0);
	instruct_sflushtx(&cc2520->spi);
	enable_reception(cc2520);

	return -EIO;
}

static int cc2520_start(struct device *dev)
{
	struct cc2520_context *cc2520 = dev->driver_data;

	SYS_LOG_DBG("\n");

	if (!instruct_sxoscon(&cc2520->spi) ||
	    !instruct_srxon(&cc2520->spi) ||
	    !verify_osc_stabilization(cc2520)) {
		return -EIO;
	}

	flush_rxfifo(cc2520);

	enable_fifop_interrupt(cc2520, true);
	enable_sfd_interrupt(cc2520, true);

	return 0;
}

static int cc2520_stop(struct device *dev)
{
	struct cc2520_context *cc2520 = dev->driver_data;

	SYS_LOG_DBG("\n");

	enable_fifop_interrupt(cc2520, false);
	enable_sfd_interrupt(cc2520, false);

	if (!instruct_srfoff(&cc2520->spi) ||
	    !instruct_sxoscoff(&cc2520->spi)) {
		return -EIO;
	}

	flush_rxfifo(cc2520);

	return 0;
}


/******************
 * Initialization *
 *****************/
static int power_on_and_setup(struct device *dev)
{
	struct cc2520_context *cc2520 = dev->driver_data;

	/* Switching to LPM2 mode */
	set_reset(dev, 0);
	_usleep(150);

	set_vreg_en(dev, 0);
	_usleep(250);

	/* Then to ACTIVE mode */
	set_vreg_en(dev, 1);
	_usleep(250);

	set_reset(dev, 1);
	_usleep(150);

	if (!verify_osc_stabilization(cc2520)) {
		return -EIO;
	}

	/* Default settings to always write (see chapter 28 part 1) */
	if (!write_reg_txpower(&cc2520->spi, CC2520_TXPOWER_DEFAULT) ||
	    !write_reg_ccactrl0(&cc2520->spi, CC2520_CCACTRL0_DEFAULT) ||
	    !write_reg_mdmctrl0(&cc2520->spi, CC2520_MDMCTRL0_DEFAULT) ||
	    !write_reg_mdmctrl1(&cc2520->spi, CC2520_MDMCTRL1_DEFAULT) ||
	    !write_reg_rxctrl(&cc2520->spi, CC2520_RXCTRL_DEFAULT) ||
	    !write_reg_fsctrl(&cc2520->spi, CC2520_FSCTRL_DEFAULT) ||
	    !write_reg_fscal1(&cc2520->spi, CC2520_FSCAL1_DEFAULT) ||
	    !write_reg_agcctrl1(&cc2520->spi, CC2520_AGCCTRL1_DEFAULT) ||
	    !write_reg_adctest0(&cc2520->spi, CC2520_ADCTEST0_DEFAULT) ||
	    !write_reg_adctest1(&cc2520->spi, CC2520_ADCTEST1_DEFAULT) ||
	    !write_reg_adctest2(&cc2520->spi, CC2520_ADCTEST2_DEFAULT)) {
		return -EIO;
	}

	/* EXTCLOCK0: Disabling external clock
	 * FRMCTRL0: AUTOACK and AUTOCRC enabled
	 * FRMCTRL1: SET_RXENMASK_ON_TX and IGNORE_TX_UNDERF
	 * FRMFILT0: Frame filtering (setting CC2520_FRAME_FILTERING)
	 * FIFOPCTRL: Set TX threshold (setting CC2520_TX_THRESHOLD)
	 */
	if (!write_reg_extclock(&cc2520->spi, 0) ||
	    !write_reg_frmctrl0(&cc2520->spi, CC2520_AUTOMATISM) ||
	    !write_reg_frmctrl1(&cc2520->spi, FRMCTRL1_IGNORE_TX_UNDERF |
				FRMCTRL1_SET_RXENMASK_ON_TX) ||
	    !write_reg_frmfilt0(&cc2520->spi, FRMFILT0_FRAME_FILTER_EN |
				FRMFILT0_MAX_FRAME_VERSION(3)) ||
	    !write_reg_frmfilt1(&cc2520->spi, FRMFILT1_ACCEPT_ALL) ||
	    !write_reg_srcmatch(&cc2520->spi, SRCMATCH_DEFAULTS) ||
	    !write_reg_fifopctrl(&cc2520->spi,
				 FIFOPCTRL_FIFOP_THR(CC2520_TX_THRESHOLD))) {
		return -EIO;
	}

	/* Cleaning up TX fifo */
	instruct_sflushtx(&cc2520->spi);

	setup_gpio_callbacks(dev);

	_cc2520_print_gpio_config(dev);

	return 0;
}

static inline int configure_spi(struct device *dev)
{
	struct cc2520_context *cc2520 = dev->driver_data;
	struct spi_config spi_conf = {
		.config = SPI_WORD(8),
		.max_sys_freq = CONFIG_TI_CC2520_SPI_FREQ,
	};

	cc2520->spi.dev = device_get_binding(CONFIG_TI_CC2520_SPI_DRV_NAME);
	if (cc2520->spi.dev) {
		cc2520->spi.slave = CONFIG_TI_CC2520_SPI_SLAVE;

		if (spi_configure(cc2520->spi.dev, &spi_conf) != 0 ||
		    spi_slave_select(cc2520->spi.dev,
				     cc2520->spi.slave) != 0) {
			cc2520->spi.dev = NULL;
			return -EIO;
		}
	}

	return 0;
}

static int cc2520_init(struct device *dev)
{
	struct cc2520_context *cc2520 = dev->driver_data;

	device_sync_call_init(&cc2520->tx_sync);
	atomic_set(&cc2520->tx, 0);
	nano_sem_init(&cc2520->rx_lock);

	cc2520->gpios = cc2520_configure_gpios();
	if (!cc2520->gpios) {
		SYS_LOG_ERR("Configuring GPIOS failed\n");
		return -EIO;
	}

	if (configure_spi(dev) != 0) {
		SYS_LOG_ERR("Configuring SPI failed\n");
		return -EIO;
	}

	SYS_LOG_DBG("GPIO and SPI configured\n");

	if (power_on_and_setup(dev) != 0) {
		SYS_LOG_ERR("Configuring CC2520 failed\n");
		return -EIO;
	}

	task_fiber_start(cc2520->cc2520_rx_stack,
			 CONFIG_CC2520_RX_STACK_SIZE,
			 cc2520_rx, POINTER_TO_INT(dev),
			 0, 0, 0);

	return 0;
}

static void cc2520_iface_init(struct net_if *iface)
{
	struct device *dev = net_if_get_device(iface);
	struct cc2520_context *cc2520 = dev->driver_data;
	uint8_t *mac = get_mac(dev);

	SYS_LOG_DBG("cc2520_iface_init\n");

	net_if_set_link_addr(iface, mac, 8);

	cc2520->iface = iface;

	ieee802154_init(iface);
}

static struct cc2520_context cc2520_context_data;

static struct ieee802154_radio_api cc2520_radio_api = {
	.iface_api.init	= cc2520_iface_init,
	.iface_api.send	= ieee802154_radio_send,

	.cca		= cc2520_cca,
	.set_channel	= cc2520_set_channel,
	.set_pan_id	= cc2520_set_pan_id,
	.set_short_addr	= cc2520_set_short_addr,
	.set_ieee_addr	= cc2520_set_ieee_addr,
	.set_txpower	= cc2520_set_txpower,
	.start		= cc2520_start,
	.stop		= cc2520_stop,
	.tx		= cc2520_tx,
};

NET_DEVICE_INIT(cc2520, CONFIG_TI_CC2520_DRV_NAME,
		cc2520_init, &cc2520_context_data, NULL,
		CONFIG_KERNEL_INIT_PRIORITY_DEFAULT,
		&cc2520_radio_api, IEEE802154_L2,
		NET_L2_GET_CTX_TYPE(IEEE802154_L2), 127);