text: /*
   * Driver for NXP MCR20A 802.15.4 Wireless-PAN Networking controller
   *
   * Copyright (C) 2018 Xue Liu <liuxuenetmail@gmail.com>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2
   * as published by the Free Software Foundation.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   */
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/gpio/consumer.h>
  #include <linux/spi/spi.h>
  #include <linux/workqueue.h>
  #include <linux/interrupt.h>
  #include <linux/irq.h>
  #include <linux/skbuff.h>
  #include <linux/of_gpio.h>
  #include <linux/regmap.h>
  #include <linux/ieee802154.h>
  #include <linux/debugfs.h>
  
  #include <net/mac802154.h>
  #include <net/cfg802154.h>
  
  #include <linux/device.h>
  
  #include "mcr20a.h"
  
  #define	SPI_COMMAND_BUFFER		3
  
  #define REGISTER_READ			BIT(7)
  #define REGISTER_WRITE			(0 << 7)
  #define REGISTER_ACCESS			(0 << 6)
  #define PACKET_BUFF_BURST_ACCESS	BIT(6)
  #define PACKET_BUFF_BYTE_ACCESS		BIT(5)
  
  #define MCR20A_WRITE_REG(x)		(x)
  #define MCR20A_READ_REG(x)		(REGISTER_READ | (x))
  #define MCR20A_BURST_READ_PACKET_BUF	(0xC0)
  #define MCR20A_BURST_WRITE_PACKET_BUF	(0x40)
  
  #define MCR20A_CMD_REG		0x80
  #define MCR20A_CMD_REG_MASK	0x3f
  #define MCR20A_CMD_WRITE	0x40
  #define MCR20A_CMD_FB		0x20
  
  /* Number of Interrupt Request Status Register */
  #define MCR20A_IRQSTS_NUM 2 /* only IRQ_STS1 and IRQ_STS2 */
  
  /* MCR20A CCA Type */
  enum {
  	MCR20A_CCA_ED,	  // energy detect - CCA bit not active,
  			  // not to be used for T and CCCA sequences
  	MCR20A_CCA_MODE1, // energy detect - CCA bit ACTIVE
  	MCR20A_CCA_MODE2, // 802.15.4 compliant signal detect - CCA bit ACTIVE
  	MCR20A_CCA_MODE3
  };
  
  enum {
  	MCR20A_XCVSEQ_IDLE	= 0x00,
  	MCR20A_XCVSEQ_RX	= 0x01,
  	MCR20A_XCVSEQ_TX	= 0x02,
  	MCR20A_XCVSEQ_CCA	= 0x03,
  	MCR20A_XCVSEQ_TR	= 0x04,
  	MCR20A_XCVSEQ_CCCA	= 0x05,
  };
  
  /* IEEE-802.15.4 defined constants (2.4 GHz logical channels) */
  #define	MCR20A_MIN_CHANNEL	(11)
  #define	MCR20A_MAX_CHANNEL	(26)
  #define	MCR20A_CHANNEL_SPACING	(5)
  
  /* MCR20A CCA Threshold constans */
  #define MCR20A_MIN_CCA_THRESHOLD (0x6EU)
  #define MCR20A_MAX_CCA_THRESHOLD (0x00U)
  
  /* version 0C */
  #define MCR20A_OVERWRITE_VERSION (0x0C)
  
  /* MCR20A PLL configurations */
  static const u8  PLL_INT[16] = {
  	/* 2405 */ 0x0B,	/* 2410 */ 0x0B,	/* 2415 */ 0x0B,
  	/* 2420 */ 0x0B,	/* 2425 */ 0x0B,	/* 2430 */ 0x0B,
  	/* 2435 */ 0x0C,	/* 2440 */ 0x0C,	/* 2445 */ 0x0C,
  	/* 2450 */ 0x0C,	/* 2455 */ 0x0C,	/* 2460 */ 0x0C,
  	/* 2465 */ 0x0D,	/* 2470 */ 0x0D,	/* 2475 */ 0x0D,
  	/* 2480 */ 0x0D
  };
  
  static const u8 PLL_FRAC[16] = {
  	/* 2405 */ 0x28,	/* 2410 */ 0x50,	/* 2415 */ 0x78,
  	/* 2420 */ 0xA0,	/* 2425 */ 0xC8,	/* 2430 */ 0xF0,
  	/* 2435 */ 0x18,	/* 2440 */ 0x40,	/* 2445 */ 0x68,
  	/* 2450 */ 0x90,	/* 2455 */ 0xB8,	/* 2460 */ 0xE0,
  	/* 2465 */ 0x08,	/* 2470 */ 0x30,	/* 2475 */ 0x58,
  	/* 2480 */ 0x80
  };
  
  static const struct reg_sequence mar20a_iar_overwrites[] = {
  	{ IAR_MISC_PAD_CTRL,	0x02 },
  	{ IAR_VCO_CTRL1,	0xB3 },
  	{ IAR_VCO_CTRL2,	0x07 },
  	{ IAR_PA_TUNING,	0x71 },
  	{ IAR_CHF_IBUF,		0x2F },
  	{ IAR_CHF_QBUF,		0x2F },
  	{ IAR_CHF_IRIN,		0x24 },
  	{ IAR_CHF_QRIN,		0x24 },
  	{ IAR_CHF_IL,		0x24 },
  	{ IAR_CHF_QL,		0x24 },
  	{ IAR_CHF_CC1,		0x32 },
  	{ IAR_CHF_CCL,		0x1D },
  	{ IAR_CHF_CC2,		0x2D },
  	{ IAR_CHF_IROUT,	0x24 },
  	{ IAR_CHF_QROUT,	0x24 },
  	{ IAR_PA_CAL,		0x28 },
  	{ IAR_AGC_THR1,		0x55 },
  	{ IAR_AGC_THR2,		0x2D },
  	{ IAR_ATT_RSSI1,	0x5F },
  	{ IAR_ATT_RSSI2,	0x8F },
  	{ IAR_RSSI_OFFSET,	0x61 },
  	{ IAR_CHF_PMA_GAIN,	0x03 },
  	{ IAR_CCA1_THRESH,	0x50 },
  	{ IAR_CORR_NVAL,	0x13 },
  	{ IAR_ACKDELAY,		0x3D },
  };
  
  #define MCR20A_VALID_CHANNELS (0x07FFF800)
  #define MCR20A_MAX_BUF		(127)
  
  #define printdev(X) (&X->spi->dev)
  
  /* regmap information for Direct Access Register (DAR) access */
  #define MCR20A_DAR_WRITE	0x01
  #define MCR20A_DAR_READ		0x00
  #define MCR20A_DAR_NUMREGS	0x3F
  
  /* regmap information for Indirect Access Register (IAR) access */
  #define MCR20A_IAR_ACCESS	0x80
  #define MCR20A_IAR_NUMREGS	0xBEFF
  
  /* Read/Write SPI Commands for DAR and IAR registers. */
  #define MCR20A_READSHORT(reg)	((reg) << 1)
  #define MCR20A_WRITESHORT(reg)	((reg) << 1 | 1)
  #define MCR20A_READLONG(reg)	(1 << 15 | (reg) << 5)
  #define MCR20A_WRITELONG(reg)	(1 << 15 | (reg) << 5 | 1 << 4)
  
  /* Type definitions for link configuration of instantiable layers  */
  #define MCR20A_PHY_INDIRECT_QUEUE_SIZE (12)
  
  static bool
  mcr20a_dar_writeable(struct device *dev, unsigned int reg)
  {
  	switch (reg) {
  	case DAR_IRQ_STS1:
  	case DAR_IRQ_STS2:
  	case DAR_IRQ_STS3:
  	case DAR_PHY_CTRL1:
  	case DAR_PHY_CTRL2:
  	case DAR_PHY_CTRL3:
  	case DAR_PHY_CTRL4:
  	case DAR_SRC_CTRL:
  	case DAR_SRC_ADDRS_SUM_LSB:
  	case DAR_SRC_ADDRS_SUM_MSB:
  	case DAR_T3CMP_LSB:
  	case DAR_T3CMP_MSB:
  	case DAR_T3CMP_USB:
  	case DAR_T2PRIMECMP_LSB:
  	case DAR_T2PRIMECMP_MSB:
  	case DAR_T1CMP_LSB:
  	case DAR_T1CMP_MSB:
  	case DAR_T1CMP_USB:
  	case DAR_T2CMP_LSB:
  	case DAR_T2CMP_MSB:
  	case DAR_T2CMP_USB:
  	case DAR_T4CMP_LSB:
  	case DAR_T4CMP_MSB:
  	case DAR_T4CMP_USB:
  	case DAR_PLL_INT0:
  	case DAR_PLL_FRAC0_LSB:
  	case DAR_PLL_FRAC0_MSB:
  	case DAR_PA_PWR:
  	/* no DAR_ACM */
  	case DAR_OVERWRITE_VER:
  	case DAR_CLK_OUT_CTRL:
  	case DAR_PWR_MODES:
  		return true;
  	default:
  		return false;
  	}
  }
  
  static bool
  mcr20a_dar_readable(struct device *dev, unsigned int reg)
  {
  	bool rc;
  
  	/* all writeable are also readable */
  	rc = mcr20a_dar_writeable(dev, reg);
  	if (rc)
  		return rc;
  
  	/* readonly regs */
  	switch (reg) {
  	case DAR_RX_FRM_LEN:
  	case DAR_CCA1_ED_FNL:
  	case DAR_EVENT_TMR_LSB:
  	case DAR_EVENT_TMR_MSB:
  	case DAR_EVENT_TMR_USB:
  	case DAR_TIMESTAMP_LSB:
  	case DAR_TIMESTAMP_MSB:
  	case DAR_TIMESTAMP_USB:
  	case DAR_SEQ_STATE:
  	case DAR_LQI_VALUE:
  	case DAR_RSSI_CCA_CONT:
  		return true;
  	default:
  		return false;
  	}
  }
  
  static bool
  mcr20a_dar_volatile(struct device *dev, unsigned int reg)
  {
  	/* can be changed during runtime */
  	switch (reg) {
  	case DAR_IRQ_STS1:
  	case DAR_IRQ_STS2:
  	case DAR_IRQ_STS3:
  	/* use them in spi_async and regmap so it's volatile */
  		return true;
  	default:
  		return false;
  	}
  }
  
  static bool
  mcr20a_dar_precious(struct device *dev, unsigned int reg)
  {
  	/* don't clear irq line on read */
  	switch (reg) {
  	case DAR_IRQ_STS1:
  	case DAR_IRQ_STS2:
  	case DAR_IRQ_STS3:
  		return true;
  	default:
  		return false;
  	}
  }
  
  static const struct regmap_config mcr20a_dar_regmap = {
  	.name			= "mcr20a_dar",
  	.reg_bits		= 8,
  	.val_bits		= 8,
  	.write_flag_mask	= REGISTER_ACCESS | REGISTER_WRITE,
  	.read_flag_mask		= REGISTER_ACCESS | REGISTER_READ,
  	.cache_type		= REGCACHE_RBTREE,
  	.writeable_reg		= mcr20a_dar_writeable,
  	.readable_reg		= mcr20a_dar_readable,
  	.volatile_reg		= mcr20a_dar_volatile,
  	.precious_reg		= mcr20a_dar_precious,
  	.fast_io		= true,
  	.can_multi_write	= true,
  };
  
  static bool
  mcr20a_iar_writeable(struct device *dev, unsigned int reg)
  {
  	switch (reg) {
  	case IAR_XTAL_TRIM:
  	case IAR_PMC_LP_TRIM:
  	case IAR_MACPANID0_LSB:
  	case IAR_MACPANID0_MSB:
  	case IAR_MACSHORTADDRS0_LSB:
  	case IAR_MACSHORTADDRS0_MSB:
  	case IAR_MACLONGADDRS0_0:
  	case IAR_MACLONGADDRS0_8:
  	case IAR_MACLONGADDRS0_16:
  	case IAR_MACLONGADDRS0_24:
  	case IAR_MACLONGADDRS0_32:
  	case IAR_MACLONGADDRS0_40:
  	case IAR_MACLONGADDRS0_48:
  	case IAR_MACLONGADDRS0_56:
  	case IAR_RX_FRAME_FILTER:
  	case IAR_PLL_INT1:
  	case IAR_PLL_FRAC1_LSB:
  	case IAR_PLL_FRAC1_MSB:
  	case IAR_MACPANID1_LSB:
  	case IAR_MACPANID1_MSB:
  	case IAR_MACSHORTADDRS1_LSB:
  	case IAR_MACSHORTADDRS1_MSB:
  	case IAR_MACLONGADDRS1_0:
  	case IAR_MACLONGADDRS1_8:
  	case IAR_MACLONGADDRS1_16:
  	case IAR_MACLONGADDRS1_24:
  	case IAR_MACLONGADDRS1_32:
  	case IAR_MACLONGADDRS1_40:
  	case IAR_MACLONGADDRS1_48:
  	case IAR_MACLONGADDRS1_56:
  	case IAR_DUAL_PAN_CTRL:
  	case IAR_DUAL_PAN_DWELL:
  	case IAR_CCA1_THRESH:
  	case IAR_CCA1_ED_OFFSET_COMP:
  	case IAR_LQI_OFFSET_COMP:
  	case IAR_CCA_CTRL:
  	case IAR_CCA2_CORR_PEAKS:
  	case IAR_CCA2_CORR_THRESH:
  	case IAR_TMR_PRESCALE:
  	case IAR_ANT_PAD_CTRL:
  	case IAR_MISC_PAD_CTRL:
  	case IAR_BSM_CTRL:
  	case IAR_RNG:
  	case IAR_RX_WTR_MARK:
  	case IAR_SOFT_RESET:
  	case IAR_TXDELAY:
  	case IAR_ACKDELAY:
  	case IAR_CORR_NVAL:
  	case IAR_ANT_AGC_CTRL:
  	case IAR_AGC_THR1:
  	case IAR_AGC_THR2:
  	case IAR_PA_CAL:
  	case IAR_ATT_RSSI1:
  	case IAR_ATT_RSSI2:
  	case IAR_RSSI_OFFSET:
  	case IAR_XTAL_CTRL:
  	case IAR_CHF_PMA_GAIN:
  	case IAR_CHF_IBUF:
  	case IAR_CHF_QBUF:
  	case IAR_CHF_IRIN:
  	case IAR_CHF_QRIN:
  	case IAR_CHF_IL:
  	case IAR_CHF_QL:
  	case IAR_CHF_CC1:
  	case IAR_CHF_CCL:
  	case IAR_CHF_CC2:
  	case IAR_CHF_IROUT:
  	case IAR_CHF_QROUT:
  	case IAR_PA_TUNING:
  	case IAR_VCO_CTRL1:
  	case IAR_VCO_CTRL2:
  		return true;
  	default:
  		return false;
  	}
  }
  
  static bool
  mcr20a_iar_readable(struct device *dev, unsigned int reg)
  {
  	bool rc;
  
  	/* all writeable are also readable */
  	rc = mcr20a_iar_writeable(dev, reg);
  	if (rc)
  		return rc;
  
  	/* readonly regs */
  	switch (reg) {
  	case IAR_PART_ID:
  	case IAR_DUAL_PAN_STS:
  	case IAR_RX_BYTE_COUNT:
  	case IAR_FILTERFAIL_CODE1:
  	case IAR_FILTERFAIL_CODE2:
  	case IAR_RSSI:
  		return true;
  	default:
  		return false;
  	}
  }
  
  static bool
  mcr20a_iar_volatile(struct device *dev, unsigned int reg)
  {
  /* can be changed during runtime */
  	switch (reg) {
  	case IAR_DUAL_PAN_STS:
  	case IAR_RX_BYTE_COUNT:
  	case IAR_FILTERFAIL_CODE1:
  	case IAR_FILTERFAIL_CODE2:
  	case IAR_RSSI:
  		return true;
  	default:
  		return false;
  	}
  }
  
  static const struct regmap_config mcr20a_iar_regmap = {
  	.name			= "mcr20a_iar",
  	.reg_bits		= 16,
  	.val_bits		= 8,
  	.write_flag_mask	= REGISTER_ACCESS | REGISTER_WRITE | IAR_INDEX,
  	.read_flag_mask		= REGISTER_ACCESS | REGISTER_READ  | IAR_INDEX,
  	.cache_type		= REGCACHE_RBTREE,
  	.writeable_reg		= mcr20a_iar_writeable,
  	.readable_reg		= mcr20a_iar_readable,
  	.volatile_reg		= mcr20a_iar_volatile,
  	.fast_io		= true,
  };
  
  struct mcr20a_local {
  	struct spi_device *spi;
  
  	struct ieee802154_hw *hw;
  	struct regmap *regmap_dar;
  	struct regmap *regmap_iar;
  
  	u8 *buf;
  
  	bool is_tx;
  
  	/* for writing tx buffer */
  	struct spi_message tx_buf_msg;
  	u8 tx_header[1];
  	/* burst buffer write command */
  	struct spi_transfer tx_xfer_header;
  	u8 tx_len[1];
  	/* len of tx packet */
  	struct spi_transfer tx_xfer_len;
  	/* data of tx packet */
  	struct spi_transfer tx_xfer_buf;
  	struct sk_buff *tx_skb;
  
  	/* for read length rxfifo */
  	struct spi_message reg_msg;
  	u8 reg_cmd[1];
  	u8 reg_data[MCR20A_IRQSTS_NUM];
  	struct spi_transfer reg_xfer_cmd;
  	struct spi_transfer reg_xfer_data;
  
  	/* receive handling */
  	struct spi_message rx_buf_msg;
  	u8 rx_header[1];
  	struct spi_transfer rx_xfer_header;
  	u8 rx_lqi[1];
  	struct spi_transfer rx_xfer_lqi;
  	u8 rx_buf[MCR20A_MAX_BUF];
  	struct spi_transfer rx_xfer_buf;
  
  	/* isr handling for reading intstat */
  	struct spi_message irq_msg;
  	u8 irq_header[1];
  	u8 irq_data[MCR20A_IRQSTS_NUM];
  	struct spi_transfer irq_xfer_data;
  	struct spi_transfer irq_xfer_header;
  };
  
  static void
  mcr20a_write_tx_buf_complete(void *context)
  {
  	struct mcr20a_local *lp = context;
  	int ret;
  
  	dev_dbg(printdev(lp), "%s\n", __func__);
  
  	lp->reg_msg.complete = NULL;
  	lp->reg_cmd[0]	= MCR20A_WRITE_REG(DAR_PHY_CTRL1);
  	lp->reg_data[0] = MCR20A_XCVSEQ_TX;
  	lp->reg_xfer_data.len = 1;
  
  	ret = spi_async(lp->spi, &lp->reg_msg);
  	if (ret)
  		dev_err(printdev(lp), "failed to set SEQ TX\n");
  }
  
  static int
  mcr20a_xmit(struct ieee802154_hw *hw, struct sk_buff *skb)
  {
  	struct mcr20a_local *lp = hw->priv;
  
  	dev_dbg(printdev(lp), "%s\n", __func__);
  
  	lp->tx_skb = skb;
  
  	print_hex_dump_debug("mcr20a tx: ", DUMP_PREFIX_OFFSET, 16, 1,
  			     skb->data, skb->len, 0);
  
  	lp->is_tx = 1;
  
  	lp->reg_msg.complete	= NULL;
  	lp->reg_cmd[0]		= MCR20A_WRITE_REG(DAR_PHY_CTRL1);
  	lp->reg_data[0]		= MCR20A_XCVSEQ_IDLE;
  	lp->reg_xfer_data.len	= 1;
  
  	return spi_async(lp->spi, &lp->reg_msg);
  }
  
  static int
  mcr20a_ed(struct ieee802154_hw *hw, u8 *level)
  {
  	WARN_ON(!level);
  	*level = 0xbe;
  	return 0;
  }
  
  static int
  mcr20a_set_channel(struct ieee802154_hw *hw, u8 page, u8 channel)
  {
  	struct mcr20a_local *lp = hw->priv;
  	int ret;
  
  	dev_dbg(printdev(lp), "%s\n", __func__);
  
  	/* freqency = ((PLL_INT+64) + (PLL_FRAC/65536)) * 32 MHz */
  	ret = regmap_write(lp->regmap_dar, DAR_PLL_INT0, PLL_INT[channel - 11]);
  	if (ret)
  		return ret;
  	ret = regmap_write(lp->regmap_dar, DAR_PLL_FRAC0_LSB, 0x00);
  	if (ret)
  		return ret;
  	ret = regmap_write(lp->regmap_dar, DAR_PLL_FRAC0_MSB,
  			   PLL_FRAC[channel - 11]);
  	if (ret)
  		return ret;
  
  	return 0;
  }
  
  static int
  mcr20a_start(struct ieee802154_hw *hw)
  {
  	struct mcr20a_local *lp = hw->priv;
  	int ret;
  
  	dev_dbg(printdev(lp), "%s\n", __func__);
  
  	/* No slotted operation */
  	dev_dbg(printdev(lp), "no slotted operation\n");
  	ret = regmap_update_bits(lp->regmap_dar, DAR_PHY_CTRL1,
  				 DAR_PHY_CTRL1_SLOTTED, 0x0);
  
  	/* enable irq */
  	enable_irq(lp->spi->irq);
  
  	/* Unmask SEQ interrupt */
  	ret = regmap_update_bits(lp->regmap_dar, DAR_PHY_CTRL2,
  				 DAR_PHY_CTRL2_SEQMSK, 0x0);
  
  	/* Start the RX sequence */
  	dev_dbg(printdev(lp), "start the RX sequence\n");
  	ret = regmap_update_bits(lp->regmap_dar, DAR_PHY_CTRL1,
  				 DAR_PHY_CTRL1_XCVSEQ_MASK, MCR20A_XCVSEQ_RX);
  
  	return 0;
  }
  
  static void
  mcr20a_stop(struct ieee802154_hw *hw)
  {
  	struct mcr20a_local *lp = hw->priv;
  
  	dev_dbg(printdev(lp), "%s\n", __func__);
  
  	/* stop all running sequence */
  	regmap_update_bits(lp->regmap_dar, DAR_PHY_CTRL1,
  			   DAR_PHY_CTRL1_XCVSEQ_MASK, MCR20A_XCVSEQ_IDLE);
  
  	/* disable irq */
  	disable_irq(lp->spi->irq);
  }
  
  static int
  mcr20a_set_hw_addr_filt(struct ieee802154_hw *hw,
  			struct ieee802154_hw_addr_filt *filt,
  			unsigned long changed)
  {
  	struct mcr20a_local *lp = hw->priv;
  
  	dev_dbg(printdev(lp), "%s\n", __func__);
  
  	if (changed & IEEE802154_AFILT_SADDR_CHANGED) {
  		u16 addr = le16_to_cpu(filt->short_addr);
  
  		regmap_write(lp->regmap_iar, IAR_MACSHORTADDRS0_LSB, addr);
  		regmap_write(lp->regmap_iar, IAR_MACSHORTADDRS0_MSB, addr >> 8);
  	}
  
  	if (changed & IEEE802154_AFILT_PANID_CHANGED) {
  		u16 pan = le16_to_cpu(filt->pan_id);
  
  		regmap_write(lp->regmap_iar, IAR_MACPANID0_LSB, pan);
  		regmap_write(lp->regmap_iar, IAR_MACPANID0_MSB, pan >> 8);
  	}
  
  	if (changed & IEEE802154_AFILT_IEEEADDR_CHANGED) {
  		u8 addr[8], i;
  
  		memcpy(addr, &filt->ieee_addr, 8);
  		for (i = 0; i < 8; i++)
  			regmap_write(lp->regmap_iar,
  				     IAR_MACLONGADDRS0_0 + i, addr[i]);
  	}
  
  	if (changed & IEEE802154_AFILT_PANC_CHANGED) {
  		if (filt->pan_coord) {
  			regmap_update_bits(lp->regmap_dar, DAR_PHY_CTRL4,
  					   DAR_PHY_CTRL4_PANCORDNTR0, 0x10);
  		} else {
  			regmap_update_bits(lp->regmap_dar, DAR_PHY_CTRL4,
  					   DAR_PHY_CTRL4_PANCORDNTR0, 0x00);
  		}
  	}
  
  	return 0;
  }
  
  /* -30 dBm to 10 dBm */
  #define MCR20A_MAX_TX_POWERS 0x14
  static const s32 mcr20a_powers[MCR20A_MAX_TX_POWERS + 1] = {
  	-3000, -2800, -2600, -2400, -2200, -2000, -1800, -1600, -1400,
  	-1200, -1000, -800, -600, -400, -200, 0, 200, 400, 600, 800, 1000
  };
  
  static int
  mcr20a_set_txpower(struct ieee802154_hw *hw, s32 mbm)
  {
  	struct mcr20a_local *lp = hw->priv;
  	u32 i;
  
  	dev_dbg(printdev(lp), "%s(%d)\n", __func__, mbm);
  
  	for (i = 0; i < lp->hw->phy->supported.tx_powers_size; i++) {
  		if (lp->hw->phy->supported.tx_powers[i] == mbm)
  			return regmap_write(lp->regmap_dar, DAR_PA_PWR,
  					    ((i + 8) & 0x1F));
  	}
  
  	return -EINVAL;
  }
  
  #define MCR20A_MAX_ED_LEVELS MCR20A_MIN_CCA_THRESHOLD
  static s32 mcr20a_ed_levels[MCR20A_MAX_ED_LEVELS + 1];
  
  static int
  mcr20a_set_cca_mode(struct ieee802154_hw *hw,
  		    const struct wpan_phy_cca *cca)
  {
  	struct mcr20a_local *lp = hw->priv;
  	unsigned int cca_mode = 0xff;
  	bool cca_mode_and = false;
  	int ret;
  
  	dev_dbg(printdev(lp), "%s\n", __func__);
  
  	/* mapping 802.15.4 to driver spec */
  	switch (cca->mode) {
  	case NL802154_CCA_ENERGY:
  		cca_mode = MCR20A_CCA_MODE1;
  		break;
  	case NL802154_CCA_CARRIER:
  		cca_mode = MCR20A_CCA_MODE2;
  		break;
  	case NL802154_CCA_ENERGY_CARRIER:
  		switch (cca->opt) {
  		case NL802154_CCA_OPT_ENERGY_CARRIER_AND:
  			cca_mode = MCR20A_CCA_MODE3;
  			cca_mode_and = true;
  			break;
  		case NL802154_CCA_OPT_ENERGY_CARRIER_OR:
  			cca_mode = MCR20A_CCA_MODE3;
  			cca_mode_and = false;
  			break;
  		default:
  			return -EINVAL;
  		}
  		break;
  	default:
  		return -EINVAL;
  	}
  	ret = regmap_update_bits(lp->regmap_dar, DAR_PHY_CTRL4,
  				 DAR_PHY_CTRL4_CCATYPE_MASK,
  				 cca_mode << DAR_PHY_CTRL4_CCATYPE_SHIFT);
  	if (ret < 0)
  		return ret;
  
  	if (cca_mode == MCR20A_CCA_MODE3) {
  		if (cca_mode_and) {
  			ret = regmap_update_bits(lp->regmap_iar, IAR_CCA_CTRL,
  						 IAR_CCA_CTRL_CCA3_AND_NOT_OR,
  						 0x08);
  		} else {
  			ret = regmap_update_bits(lp->regmap_iar,
  						 IAR_CCA_CTRL,
  						 IAR_CCA_CTRL_CCA3_AND_NOT_OR,
  						 0x00);
  		}
  		if (ret < 0)
  			return ret;
  	}
  
  	return ret;
  }
  
  static int
  mcr20a_set_cca_ed_level(struct ieee802154_hw *hw, s32 mbm)
  {
  	struct mcr20a_local *lp = hw->priv;
  	u32 i;
  
  	dev_dbg(printdev(lp), "%s\n", __func__);
  
  	for (i = 0; i < hw->phy->supported.cca_ed_levels_size; i++) {
  		if (hw->phy->supported.cca_ed_levels[i] == mbm)
  			return regmap_write(lp->regmap_iar, IAR_CCA1_THRESH, i);
  	}
  
  	return 0;
  }
  
  static int
  mcr20a_set_promiscuous_mode(struct ieee802154_hw *hw, const bool on)
  {
  	struct mcr20a_local *lp = hw->priv;
  	int ret;
  	u8 rx_frame_filter_reg = 0x0;
  
  	dev_dbg(printdev(lp), "%s(%d)\n", __func__, on);
  
  	if (on) {
  		/* All frame types accepted*/
  		rx_frame_filter_reg &= ~(IAR_RX_FRAME_FLT_FRM_VER);
  		rx_frame_filter_reg |= (IAR_RX_FRAME_FLT_ACK_FT |
  				  IAR_RX_FRAME_FLT_NS_FT);
  
  		ret = regmap_update_bits(lp->regmap_dar, DAR_PHY_CTRL4,
  					 DAR_PHY_CTRL4_PROMISCUOUS,
  					 DAR_PHY_CTRL4_PROMISCUOUS);
  		if (ret < 0)
  			return ret;
  
  		ret = regmap_write(lp->regmap_iar, IAR_RX_FRAME_FILTER,
  				   rx_frame_filter_reg);
  		if (ret < 0)
  			return ret;
  	} else {
  		ret = regmap_update_bits(lp->regmap_dar, DAR_PHY_CTRL4,
  					 DAR_PHY_CTRL4_PROMISCUOUS, 0x0);
  		if (ret < 0)
  			return ret;
  
  		ret = regmap_write(lp->regmap_iar, IAR_RX_FRAME_FILTER,
  				   IAR_RX_FRAME_FLT_FRM_VER |
  				   IAR_RX_FRAME_FLT_BEACON_FT |
  				   IAR_RX_FRAME_FLT_DATA_FT |
  				   IAR_RX_FRAME_FLT_CMD_FT);
  		if (ret < 0)
  			return ret;
  	}
  
  	return 0;
  }
  
  static const struct ieee802154_ops mcr20a_hw_ops = {
  	.owner			= THIS_MODULE,
  	.xmit_async		= mcr20a_xmit,
  	.ed			= mcr20a_ed,
  	.set_channel		= mcr20a_set_channel,
  	.start			= mcr20a_start,
  	.stop			= mcr20a_stop,
  	.set_hw_addr_filt	= mcr20a_set_hw_addr_filt,
  	.set_txpower		= mcr20a_set_txpower,
  	.set_cca_mode		= mcr20a_set_cca_mode,
  	.set_cca_ed_level	= mcr20a_set_cca_ed_level,
  	.set_promiscuous_mode	= mcr20a_set_promiscuous_mode,
  };
  
  static int
  mcr20a_request_rx(struct mcr20a_local *lp)
  {
  	dev_dbg(printdev(lp), "%s\n", __func__);
  
  	/* Start the RX sequence */
  	regmap_update_bits_async(lp->regmap_dar, DAR_PHY_CTRL1,
  				 DAR_PHY_CTRL1_XCVSEQ_MASK, MCR20A_XCVSEQ_RX);
  
  	return 0;
  }
  
  static void
  mcr20a_handle_rx_read_buf_complete(void *context)
  {
  	struct mcr20a_local *lp = context;
  	u8 len = lp->reg_data[0] & DAR_RX_FRAME_LENGTH_MASK;
  	struct sk_buff *skb;
  
  	dev_dbg(printdev(lp), "%s\n", __func__);
  
  	dev_dbg(printdev(lp), "RX is done\n");
  
  	if (!ieee802154_is_valid_psdu_len(len)) {
  		dev_vdbg(&lp->spi->dev, "corrupted frame received\n");
  		len = IEEE802154_MTU;
  	}
  
  	len = len - 2;  /* get rid of frame check field */
  
  	skb = dev_alloc_skb(len);
  	if (!skb)
  		return;
  
  	memcpy(skb_put(skb, len), lp->rx_buf, len);
  	ieee802154_rx_irqsafe(lp->hw, skb, lp->rx_lqi[0]);
  
  	print_hex_dump_debug("mcr20a rx: ", DUMP_PREFIX_OFFSET, 16, 1,
  			     lp->rx_buf, len, 0);
  	pr_debug("mcr20a rx: lqi: %02hhx\n", lp->rx_lqi[0]);
  
  	/* start RX sequence */
  	mcr20a_request_rx(lp);
  }
  
  static void
  mcr20a_handle_rx_read_len_complete(void *context)
  {
  	struct mcr20a_local *lp = context;
  	u8 len;
  	int ret;
  
  	dev_dbg(printdev(lp), "%s\n", __func__);
  
  	/* get the length of received frame */
  	len = lp->reg_data[0] & DAR_RX_FRAME_LENGTH_MASK;
  	dev_dbg(printdev(lp), "frame len : %d\n", len);
  
  	/* prepare to read the rx buf */
  	lp->rx_buf_msg.complete = mcr20a_handle_rx_read_buf_complete;
  	lp->rx_header[0] = MCR20A_BURST_READ_PACKET_BUF;
  	lp->rx_xfer_buf.len = len;
  
  	ret = spi_async(lp->spi, &lp->rx_buf_msg);
  	if (ret)
  		dev_err(printdev(lp), "failed to read rx buffer length\n");
  }
  
  static int
  mcr20a_handle_rx(struct mcr20a_local *lp)
  {
  	dev_dbg(printdev(lp), "%s\n", __func__);
  	lp->reg_msg.complete = mcr20a_handle_rx_read_len_complete;
  	lp->reg_cmd[0] = MCR20A_READ_REG(DAR_RX_FRM_LEN);
  	lp->reg_xfer_data.len	= 1;
  
  	return spi_async(lp->spi, &lp->reg_msg);
  }
  
  static int
  mcr20a_handle_tx_complete(struct mcr20a_local *lp)
  {
  	dev_dbg(printdev(lp), "%s\n", __func__);
  
  	ieee802154_xmit_complete(lp->hw, lp->tx_skb, false);
  
  	return mcr20a_request_rx(lp);
  }
  
  static int
  mcr20a_handle_tx(struct mcr20a_local *lp)
  {
  	int ret;
  
  	dev_dbg(printdev(lp), "%s\n", __func__);
  
  	/* write tx buffer */
  	lp->tx_header[0]	= MCR20A_BURST_WRITE_PACKET_BUF;
  	/* add 2 bytes of FCS */
  	lp->tx_len[0]		= lp->tx_skb->len + 2;
  	lp->tx_xfer_buf.tx_buf	= lp->tx_skb->data;
  	/* add 1 byte psduLength */
  	lp->tx_xfer_buf.len	= lp->tx_skb->len + 1;
  
  	ret = spi_async(lp->spi, &lp->tx_buf_msg);
  	if (ret) {
  		dev_err(printdev(lp), "SPI write Failed for TX buf\n");
  		return ret;
  	}
  
  	return 0;
  }
  
  static void
  mcr20a_irq_clean_complete(void *context)
  {
  	struct mcr20a_local *lp = context;
  	u8 seq_state = lp->irq_data[DAR_IRQ_STS1] & DAR_PHY_CTRL1_XCVSEQ_MASK;
  
  	dev_dbg(printdev(lp), "%s\n", __func__);
  
  	enable_irq(lp->spi->irq);
  
  	dev_dbg(printdev(lp), "IRQ STA1 (%02x) STA2 (%02x)\n",
  		lp->irq_data[DAR_IRQ_STS1], lp->irq_data[DAR_IRQ_STS2]);
  
  	switch (seq_state) {
  	/* TX IRQ, RX IRQ and SEQ IRQ */
  	case (DAR_IRQSTS1_TXIRQ | DAR_IRQSTS1_SEQIRQ):
  		if (lp->is_tx) {
  			lp->is_tx = 0;
  			dev_dbg(printdev(lp), "TX is done. No ACK\n");
  			mcr20a_handle_tx_complete(lp);
  		}
  		break;
  	case (DAR_IRQSTS1_RXIRQ | DAR_IRQSTS1_SEQIRQ):
  			/* rx is starting */
  			dev_dbg(printdev(lp), "RX is starting\n");
  			mcr20a_handle_rx(lp);
  		break;
  	case (DAR_IRQSTS1_RXIRQ | DAR_IRQSTS1_TXIRQ | DAR_IRQSTS1_SEQIRQ):
  		if (lp->is_tx) {
  			/* tx is done */
  			lp->is_tx = 0;
  			dev_dbg(printdev(lp), "TX is done. Get ACK\n");
  			mcr20a_handle_tx_complete(lp);
  		} else {
  			/* rx is starting */
  			dev_dbg(printdev(lp), "RX is starting\n");
  			mcr20a_handle_rx(lp);
  		}
  		break;
  	case (DAR_IRQSTS1_SEQIRQ):
  		if (lp->is_tx) {
  			dev_dbg(printdev(lp), "TX is starting\n");
  			mcr20a_handle_tx(lp);
  		} else {
  			dev_dbg(printdev(lp), "MCR20A is stop\n");
  		}
  		break;
  	}
  }
  
  static void mcr20a_irq_status_complete(void *context)
  {
  	int ret;
  	struct mcr20a_local *lp = context;
  
  	dev_dbg(printdev(lp), "%s\n", __func__);
  	regmap_update_bits_async(lp->regmap_dar, DAR_PHY_CTRL1,
  				 DAR_PHY_CTRL1_XCVSEQ_MASK, MCR20A_XCVSEQ_IDLE);
  
  	lp->reg_msg.complete = mcr20a_irq_clean_complete;
  	lp->reg_cmd[0] = MCR20A_WRITE_REG(DAR_IRQ_STS1);
  	memcpy(lp->reg_data, lp->irq_data, MCR20A_IRQSTS_NUM);
  	lp->reg_xfer_data.len = MCR20A_IRQSTS_NUM;
  
  	ret = spi_async(lp->spi, &lp->reg_msg);
  
  	if (ret)
  		dev_err(printdev(lp), "failed to clean irq status\n");
  }
  
  static irqreturn_t mcr20a_irq_isr(int irq, void *data)
  {
  	struct mcr20a_local *lp = data;
  	int ret;
  
  	disable_irq_nosync(irq);
  
  	lp->irq_header[0] = MCR20A_READ_REG(DAR_IRQ_STS1);
  	/* read IRQSTSx */
  	ret = spi_async(lp->spi, &lp->irq_msg);
  	if (ret) {
  		enable_irq(irq);
  		return IRQ_NONE;
  	}
  
  	return IRQ_HANDLED;
  }
  
  static void mcr20a_hw_setup(struct mcr20a_local *lp)
  {
  	u8 i;
  	struct ieee802154_hw *hw = lp->hw;
  	struct wpan_phy *phy = lp->hw->phy;
  
  	dev_dbg(printdev(lp), "%s\n", __func__);
  
  	phy->symbol_duration = 16;
  	phy->lifs_period = 40;
  	phy->sifs_period = 12;
  
  	hw->flags = IEEE802154_HW_TX_OMIT_CKSUM |
  			IEEE802154_HW_AFILT |
  			IEEE802154_HW_PROMISCUOUS;
  
  	phy->flags = WPAN_PHY_FLAG_TXPOWER | WPAN_PHY_FLAG_CCA_ED_LEVEL |
  			WPAN_PHY_FLAG_CCA_MODE;
  
  	phy->supported.cca_modes = BIT(NL802154_CCA_ENERGY) |
  		BIT(NL802154_CCA_CARRIER) | BIT(NL802154_CCA_ENERGY_CARRIER);
  	phy->supported.cca_opts = BIT(NL802154_CCA_OPT_ENERGY_CARRIER_AND) |
  		BIT(NL802154_CCA_OPT_ENERGY_CARRIER_OR);
  
  	/* initiating cca_ed_levels */
  	for (i = MCR20A_MAX_CCA_THRESHOLD; i < MCR20A_MIN_CCA_THRESHOLD + 1;
  	      ++i) {
  		mcr20a_ed_levels[i] =  -i * 100;
  	}
  
  	phy->supported.cca_ed_levels = mcr20a_ed_levels;
  	phy->supported.cca_ed_levels_size = ARRAY_SIZE(mcr20a_ed_levels);
  
  	phy->cca.mode = NL802154_CCA_ENERGY;
  
  	phy->supported.channels[0] = MCR20A_VALID_CHANNELS;
  	phy->current_page = 0;
  	/* MCR20A default reset value */
  	phy->current_channel = 20;
  	phy->symbol_duration = 16;
  	phy->supported.tx_powers = mcr20a_powers;
  	phy->supported.tx_powers_size = ARRAY_SIZE(mcr20a_powers);
  	phy->cca_ed_level = phy->supported.cca_ed_levels[75];
  	phy->transmit_power = phy->supported.tx_powers[0x0F];
  }
  
  static void
  mcr20a_setup_tx_spi_messages(struct mcr20a_local *lp)
  {
  	spi_message_init(&lp->tx_buf_msg);
  	lp->tx_buf_msg.context = lp;
  	lp->tx_buf_msg.complete = mcr20a_write_tx_buf_complete;
  
  	lp->tx_xfer_header.len = 1;
  	lp->tx_xfer_header.tx_buf = lp->tx_header;
  
  	lp->tx_xfer_len.len = 1;
  	lp->tx_xfer_len.tx_buf = lp->tx_len;
  
  	spi_message_add_tail(&lp->tx_xfer_header, &lp->tx_buf_msg);
  	spi_message_add_tail(&lp->tx_xfer_len, &lp->tx_buf_msg);
  	spi_message_add_tail(&lp->tx_xfer_buf, &lp->tx_buf_msg);
  }
  
  static void
  mcr20a_setup_rx_spi_messages(struct mcr20a_local *lp)
  {
  	spi_message_init(&lp->reg_msg);
  	lp->reg_msg.context = lp;
  
  	lp->reg_xfer_cmd.len = 1;
  	lp->reg_xfer_cmd.tx_buf = lp->reg_cmd;
  	lp->reg_xfer_cmd.rx_buf = lp->reg_cmd;
  
  	lp->reg_xfer_data.rx_buf = lp->reg_data;
  	lp->reg_xfer_data.tx_buf = lp->reg_data;
  
  	spi_message_add_tail(&lp->reg_xfer_cmd, &lp->reg_msg);
  	spi_message_add_tail(&lp->reg_xfer_data, &lp->reg_msg);
  
  	spi_message_init(&lp->rx_buf_msg);
  	lp->rx_buf_msg.context = lp;
  	lp->rx_buf_msg.complete = mcr20a_handle_rx_read_buf_complete;
  	lp->rx_xfer_header.len = 1;
  	lp->rx_xfer_header.tx_buf = lp->rx_header;
  	lp->rx_xfer_header.rx_buf = lp->rx_header;
  
  	lp->rx_xfer_buf.rx_buf = lp->rx_buf;
  
  	lp->rx_xfer_lqi.len = 1;
  	lp->rx_xfer_lqi.rx_buf = lp->rx_lqi;
  
  	spi_message_add_tail(&lp->rx_xfer_header, &lp->rx_buf_msg);
  	spi_message_add_tail(&lp->rx_xfer_buf, &lp->rx_buf_msg);
  	spi_message_add_tail(&lp->rx_xfer_lqi, &lp->rx_buf_msg);
  }
  
  static void
  mcr20a_setup_irq_spi_messages(struct mcr20a_local *lp)
  {
  	spi_message_init(&lp->irq_msg);
  	lp->irq_msg.context		= lp;
  	lp->irq_msg.complete	= mcr20a_irq_status_complete;
  	lp->irq_xfer_header.len	= 1;
  	lp->irq_xfer_header.tx_buf = lp->irq_header;
  	lp->irq_xfer_header.rx_buf = lp->irq_header;
  
  	lp->irq_xfer_data.len	= MCR20A_IRQSTS_NUM;
  	lp->irq_xfer_data.rx_buf = lp->irq_data;
  
  	spi_message_add_tail(&lp->irq_xfer_header, &lp->irq_msg);
  	spi_message_add_tail(&lp->irq_xfer_data, &lp->irq_msg);
  }
  
  static int
  mcr20a_phy_init(struct mcr20a_local *lp)
  {
  	u8 index;
  	unsigned int phy_reg = 0;
  	int ret;
  
  	dev_dbg(printdev(lp), "%s\n", __func__);
  
  	/* Disable Tristate on COCO MISO for SPI reads */
  	ret = regmap_write(lp->regmap_iar, IAR_MISC_PAD_CTRL, 0x02);
  	if (ret)
  		goto err_ret;
  
  	/* Clear all PP IRQ bits in IRQSTS1 to avoid unexpected interrupts
  	 * immediately after init
  	 */
  	ret = regmap_write(lp->regmap_dar, DAR_IRQ_STS1, 0xEF);
  	if (ret)
  		goto err_ret;
  
  	/* Clear all PP IRQ bits in IRQSTS2 */
  	ret = regmap_write(lp->regmap_dar, DAR_IRQ_STS2,
  			   DAR_IRQSTS2_ASM_IRQ | DAR_IRQSTS2_PB_ERR_IRQ |
  			   DAR_IRQSTS2_WAKE_IRQ);
  	if (ret)
  		goto err_ret;
  
  	/* Disable all timer interrupts */
  	ret = regmap_write(lp->regmap_dar, DAR_IRQ_STS3, 0xFF);
  	if (ret)
  		goto err_ret;
  
  	/*  PHY_CTRL1 : default HW settings + AUTOACK enabled */
  	ret = regmap_update_bits(lp->regmap_dar, DAR_PHY_CTRL1,
  				 DAR_PHY_CTRL1_AUTOACK, DAR_PHY_CTRL1_AUTOACK);
  
  	/*  PHY_CTRL2 : disable all interrupts */
  	ret = regmap_write(lp->regmap_dar, DAR_PHY_CTRL2, 0xFF);
  	if (ret)
  		goto err_ret;
  
  	/* PHY_CTRL3 : disable all timers and remaining interrupts */
  	ret = regmap_write(lp->regmap_dar, DAR_PHY_CTRL3,
  			   DAR_PHY_CTRL3_ASM_MSK | DAR_PHY_CTRL3_PB_ERR_MSK |
  			   DAR_PHY_CTRL3_WAKE_MSK);
  	if (ret)
  		goto err_ret;
  
  	/* SRC_CTRL : enable Acknowledge Frame Pending and
  	 * Source Address Matching Enable
  	 */
  	ret = regmap_write(lp->regmap_dar, DAR_SRC_CTRL,
  			   DAR_SRC_CTRL_ACK_FRM_PND |
  			   (DAR_SRC_CTRL_INDEX << DAR_SRC_CTRL_INDEX_SHIFT));
  	if (ret)
  		goto err_ret;
  
  	/*  RX_FRAME_FILTER */
  	/*  FRM_VER[1:0] = b11. Accept FrameVersion 0 and 1 packets */
  	ret = regmap_write(lp->regmap_iar, IAR_RX_FRAME_FILTER,
  			   IAR_RX_FRAME_FLT_FRM_VER |
  			   IAR_RX_FRAME_FLT_BEACON_FT |
  			   IAR_RX_FRAME_FLT_DATA_FT |
  			   IAR_RX_FRAME_FLT_CMD_FT);
  	if (ret)
  		goto err_ret;
  
  	dev_info(printdev(lp), "MCR20A DAR overwrites version: 0x%02x\n",
  		 MCR20A_OVERWRITE_VERSION);
  
  	/* Overwrites direct registers  */
  	ret = regmap_write(lp->regmap_dar, DAR_OVERWRITE_VER,
  			   MCR20A_OVERWRITE_VERSION);
  	if (ret)
  		goto err_ret;
  
  	/* Overwrites indirect registers  */
  	ret = regmap_multi_reg_write(lp->regmap_iar, mar20a_iar_overwrites,
  				     ARRAY_SIZE(mar20a_iar_overwrites));
  	if (ret)
  		goto err_ret;
  
  	/* Clear HW indirect queue */
  	dev_dbg(printdev(lp), "clear HW indirect queue\n");
  	for (index = 0; index < MCR20A_PHY_INDIRECT_QUEUE_SIZE; index++) {
  		phy_reg = (u8)(((index & DAR_SRC_CTRL_INDEX) <<
  			       DAR_SRC_CTRL_INDEX_SHIFT)
  			      | (DAR_SRC_CTRL_SRCADDR_EN)
  			      | (DAR_SRC_CTRL_INDEX_DISABLE));
  		ret = regmap_write(lp->regmap_dar, DAR_SRC_CTRL, phy_reg);
  		if (ret)
  			goto err_ret;
  		phy_reg = 0;
  	}
  
  	/* Assign HW Indirect hash table to PAN0 */
  	ret = regmap_read(lp->regmap_iar, IAR_DUAL_PAN_CTRL, &phy_reg);
  	if (ret)
  		goto err_ret;
  
  	/* Clear current lvl */
  	phy_reg &= ~IAR_DUAL_PAN_CTRL_DUAL_PAN_SAM_LVL_MSK;
  
  	/* Set new lvl */
  	phy_reg |= MCR20A_PHY_INDIRECT_QUEUE_SIZE <<
  		IAR_DUAL_PAN_CTRL_DUAL_PAN_SAM_LVL_SHIFT;
  	ret = regmap_write(lp->regmap_iar, IAR_DUAL_PAN_CTRL, phy_reg);
  	if (ret)
  		goto err_ret;
  
  	/* Set CCA threshold to -75 dBm */
  	ret = regmap_write(lp->regmap_iar, IAR_CCA1_THRESH, 0x4B);
  	if (ret)
  		goto err_ret;
  
  	/* Set prescaller to obtain 1 symbol (16us) timebase */
  	ret = regmap_write(lp->regmap_iar, IAR_TMR_PRESCALE, 0x05);
  	if (ret)
  		goto err_ret;
  
  	/* Enable autodoze mode. */
  	ret = regmap_update_bits(lp->regmap_dar, DAR_PWR_MODES,
  				 DAR_PWR_MODES_AUTODOZE,
  				 DAR_PWR_MODES_AUTODOZE);
  	if (ret)
  		goto err_ret;
  
  	/* Disable clk_out */
  	ret = regmap_update_bits(lp->regmap_dar, DAR_CLK_OUT_CTRL,
  				 DAR_CLK_OUT_CTRL_EN, 0x0);
  	if (ret)
  		goto err_ret;
  
  	return 0;
  
  err_ret:
  	return ret;
  }
  
  static int
  mcr20a_probe(struct spi_device *spi)
  {
  	struct ieee802154_hw *hw;
  	struct mcr20a_local *lp;
  	struct gpio_desc *rst_b;
  	int irq_type;
  	int ret = -ENOMEM;
  
  	dev_dbg(&spi->dev, "%s\n", __func__);
  
  	if (!spi->irq) {
  		dev_err(&spi->dev, "no IRQ specified\n");
  		return -EINVAL;
  	}
  
  	rst_b = devm_gpiod_get(&spi->dev, "rst_b", GPIOD_OUT_HIGH);
  	if (IS_ERR(rst_b)) {
  		ret = PTR_ERR(rst_b);
  		if (ret != -EPROBE_DEFER)
  			dev_err(&spi->dev, "Failed to get 'rst_b' gpio: %d", ret);
  		return ret;
  	}
  
  	/* reset mcr20a */
  	usleep_range(10, 20);
  	gpiod_set_value_cansleep(rst_b, 1);
  	usleep_range(10, 20);
  	gpiod_set_value_cansleep(rst_b, 0);
  	usleep_range(120, 240);
  
  	/* allocate ieee802154_hw and private data */
  	hw = ieee802154_alloc_hw(sizeof(*lp), &mcr20a_hw_ops);
  	if (!hw) {
  		dev_crit(&spi->dev, "ieee802154_alloc_hw failed\n");
  		return ret;
  	}
  
  	/* init mcr20a local data */
  	lp = hw->priv;
  	lp->hw = hw;
  	lp->spi = spi;
  
  	/* init ieee802154_hw */
  	hw->parent = &spi->dev;
  	ieee802154_random_extended_addr(&hw->phy->perm_extended_addr);
  
  	/* init buf */
  	lp->buf = devm_kzalloc(&spi->dev, SPI_COMMAND_BUFFER, GFP_KERNEL);
  
  	if (!lp->buf) {
  		ret = -ENOMEM;
  		goto free_dev;
  	}
  
  	mcr20a_setup_tx_spi_messages(lp);
  	mcr20a_setup_rx_spi_messages(lp);
  	mcr20a_setup_irq_spi_messages(lp);
  
  	/* setup regmap */
  	lp->regmap_dar = devm_regmap_init_spi(spi, &mcr20a_dar_regmap);
  	if (IS_ERR(lp->regmap_dar)) {
  		ret = PTR_ERR(lp->regmap_dar);
  		dev_err(&spi->dev, "Failed to allocate dar map: %d\n",
  			ret);
  		goto free_dev;
  	}
  
  	lp->regmap_iar = devm_regmap_init_spi(spi, &mcr20a_iar_regmap);
  	if (IS_ERR(lp->regmap_iar)) {
  		ret = PTR_ERR(lp->regmap_iar);
  		dev_err(&spi->dev, "Failed to allocate iar map: %d\n", ret);
  		goto free_dev;
  	}
  
  	mcr20a_hw_setup(lp);
  
  	spi_set_drvdata(spi, lp);
  
  	ret = mcr20a_phy_init(lp);
  	if (ret < 0) {
  		dev_crit(&spi->dev, "mcr20a_phy_init failed\n");
  		goto free_dev;
  	}
  
  	irq_type = irq_get_trigger_type(spi->irq);
  	if (!irq_type)
  		irq_type = IRQF_TRIGGER_FALLING;
  
  	ret = devm_request_irq(&spi->dev, spi->irq, mcr20a_irq_isr,
  			       irq_type, dev_name(&spi->dev), lp);
  	if (ret) {
  		dev_err(&spi->dev, "could not request_irq for mcr20a\n");
  		ret = -ENODEV;
  		goto free_dev;
  	}
  
  	/* disable_irq by default and wait for starting hardware */
  	disable_irq(spi->irq);
  
  	ret = ieee802154_register_hw(hw);
  	if (ret) {
  		dev_crit(&spi->dev, "ieee802154_register_hw failed\n");
  		goto free_dev;
  	}
  
  	return ret;
  
  free_dev:
  	ieee802154_free_hw(lp->hw);
  
  	return ret;
  }
  
  static int mcr20a_remove(struct spi_device *spi)
  {
  	struct mcr20a_local *lp = spi_get_drvdata(spi);
  
  	dev_dbg(&spi->dev, "%s\n", __func__);
  
  	ieee802154_unregister_hw(lp->hw);
  	ieee802154_free_hw(lp->hw);
  
  	return 0;
  }
  
  static const struct of_device_id mcr20a_of_match[] = {
  	{ .compatible = "nxp,mcr20a", },
  	{ },
  };
  MODULE_DEVICE_TABLE(of, mcr20a_of_match);
  
  static const struct spi_device_id mcr20a_device_id[] = {
  	{ .name = "mcr20a", },
  	{ },
  };
  MODULE_DEVICE_TABLE(spi, mcr20a_device_id);
  
  static struct spi_driver mcr20a_driver = {
  	.id_table = mcr20a_device_id,
  	.driver = {
  		.of_match_table = of_match_ptr(mcr20a_of_match),
  		.name	= "mcr20a",
  	},
  	.probe      = mcr20a_probe,
  	.remove     = mcr20a_remove,
  };
  
  module_spi_driver(mcr20a_driver);
  
  MODULE_DESCRIPTION("MCR20A Transceiver Driver");
  MODULE_LICENSE("GPL v2");
  MODULE_AUTHOR("Xue Liu <liuxuenetmail@gmail>");
  