/*
   * AT86RF230/RF231 driver
   *
   * Copyright (C) 2009-2012 Siemens AG
   *
   * 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.
   *
   * You should have received a copy of the GNU General Public License along
   * with this program; if not, write to the Free Software Foundation, Inc.,
   * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Written by:
   * Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
   * Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
   */
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/interrupt.h>
  #include <linux/gpio.h>
  #include <linux/delay.h>
  #include <linux/mutex.h>
  #include <linux/workqueue.h>
  #include <linux/spinlock.h>
  #include <linux/spi/spi.h>
  #include <linux/spi/at86rf230.h>
  #include <linux/skbuff.h>
  
  #include <net/mac802154.h>
  #include <net/wpan-phy.h>
  
  struct at86rf230_local {
  	struct spi_device *spi;
  	int rstn, slp_tr, dig2;
  
  	u8 part;
  	u8 vers;
  
  	u8 buf[2];
  	struct mutex bmux;
  
  	struct work_struct irqwork;
  	struct completion tx_complete;
  
  	struct ieee802154_dev *dev;
  
  	spinlock_t lock;
  	bool irq_busy;
  	bool is_tx;
  };
  
  #define	RG_TRX_STATUS	(0x01)
  #define	SR_TRX_STATUS		0x01, 0x1f, 0
  #define	SR_RESERVED_01_3	0x01, 0x20, 5
  #define	SR_CCA_STATUS		0x01, 0x40, 6
  #define	SR_CCA_DONE		0x01, 0x80, 7
  #define	RG_TRX_STATE	(0x02)
  #define	SR_TRX_CMD		0x02, 0x1f, 0
  #define	SR_TRAC_STATUS		0x02, 0xe0, 5
  #define	RG_TRX_CTRL_0	(0x03)
  #define	SR_CLKM_CTRL		0x03, 0x07, 0
  #define	SR_CLKM_SHA_SEL		0x03, 0x08, 3
  #define	SR_PAD_IO_CLKM		0x03, 0x30, 4
  #define	SR_PAD_IO		0x03, 0xc0, 6
  #define	RG_TRX_CTRL_1	(0x04)
  #define	SR_IRQ_POLARITY		0x04, 0x01, 0
  #define	SR_IRQ_MASK_MODE	0x04, 0x02, 1
  #define	SR_SPI_CMD_MODE		0x04, 0x0c, 2
  #define	SR_RX_BL_CTRL		0x04, 0x10, 4
  #define	SR_TX_AUTO_CRC_ON	0x04, 0x20, 5
  #define	SR_IRQ_2_EXT_EN		0x04, 0x40, 6
  #define	SR_PA_EXT_EN		0x04, 0x80, 7
  #define	RG_PHY_TX_PWR	(0x05)
  #define	SR_TX_PWR		0x05, 0x0f, 0
  #define	SR_PA_LT		0x05, 0x30, 4
  #define	SR_PA_BUF_LT		0x05, 0xc0, 6
  #define	RG_PHY_RSSI	(0x06)
  #define	SR_RSSI			0x06, 0x1f, 0
  #define	SR_RND_VALUE		0x06, 0x60, 5
  #define	SR_RX_CRC_VALID		0x06, 0x80, 7
  #define	RG_PHY_ED_LEVEL	(0x07)
  #define	SR_ED_LEVEL		0x07, 0xff, 0
  #define	RG_PHY_CC_CCA	(0x08)
  #define	SR_CHANNEL		0x08, 0x1f, 0
  #define	SR_CCA_MODE		0x08, 0x60, 5
  #define	SR_CCA_REQUEST		0x08, 0x80, 7
  #define	RG_CCA_THRES	(0x09)
  #define	SR_CCA_ED_THRES		0x09, 0x0f, 0
  #define	SR_RESERVED_09_1	0x09, 0xf0, 4
  #define	RG_RX_CTRL	(0x0a)
  #define	SR_PDT_THRES		0x0a, 0x0f, 0
  #define	SR_RESERVED_0a_1	0x0a, 0xf0, 4
  #define	RG_SFD_VALUE	(0x0b)
  #define	SR_SFD_VALUE		0x0b, 0xff, 0
  #define	RG_TRX_CTRL_2	(0x0c)
  #define	SR_OQPSK_DATA_RATE	0x0c, 0x03, 0
  #define	SR_RESERVED_0c_2	0x0c, 0x7c, 2
  #define	SR_RX_SAFE_MODE		0x0c, 0x80, 7
  #define	RG_ANT_DIV	(0x0d)
  #define	SR_ANT_CTRL		0x0d, 0x03, 0
  #define	SR_ANT_EXT_SW_EN	0x0d, 0x04, 2
  #define	SR_ANT_DIV_EN		0x0d, 0x08, 3
  #define	SR_RESERVED_0d_2	0x0d, 0x70, 4
  #define	SR_ANT_SEL		0x0d, 0x80, 7
  #define	RG_IRQ_MASK	(0x0e)
  #define	SR_IRQ_MASK		0x0e, 0xff, 0
  #define	RG_IRQ_STATUS	(0x0f)
  #define	SR_IRQ_0_PLL_LOCK	0x0f, 0x01, 0
  #define	SR_IRQ_1_PLL_UNLOCK	0x0f, 0x02, 1
  #define	SR_IRQ_2_RX_START	0x0f, 0x04, 2
  #define	SR_IRQ_3_TRX_END	0x0f, 0x08, 3
  #define	SR_IRQ_4_CCA_ED_DONE	0x0f, 0x10, 4
  #define	SR_IRQ_5_AMI		0x0f, 0x20, 5
  #define	SR_IRQ_6_TRX_UR		0x0f, 0x40, 6
  #define	SR_IRQ_7_BAT_LOW	0x0f, 0x80, 7
  #define	RG_VREG_CTRL	(0x10)
  #define	SR_RESERVED_10_6	0x10, 0x03, 0
  #define	SR_DVDD_OK		0x10, 0x04, 2
  #define	SR_DVREG_EXT		0x10, 0x08, 3
  #define	SR_RESERVED_10_3	0x10, 0x30, 4
  #define	SR_AVDD_OK		0x10, 0x40, 6
  #define	SR_AVREG_EXT		0x10, 0x80, 7
  #define	RG_BATMON	(0x11)
  #define	SR_BATMON_VTH		0x11, 0x0f, 0
  #define	SR_BATMON_HR		0x11, 0x10, 4
  #define	SR_BATMON_OK		0x11, 0x20, 5
  #define	SR_RESERVED_11_1	0x11, 0xc0, 6
  #define	RG_XOSC_CTRL	(0x12)
  #define	SR_XTAL_TRIM		0x12, 0x0f, 0
  #define	SR_XTAL_MODE		0x12, 0xf0, 4
  #define	RG_RX_SYN	(0x15)
  #define	SR_RX_PDT_LEVEL		0x15, 0x0f, 0
  #define	SR_RESERVED_15_2	0x15, 0x70, 4
  #define	SR_RX_PDT_DIS		0x15, 0x80, 7
  #define	RG_XAH_CTRL_1	(0x17)
  #define	SR_RESERVED_17_8	0x17, 0x01, 0
  #define	SR_AACK_PROM_MODE	0x17, 0x02, 1
  #define	SR_AACK_ACK_TIME	0x17, 0x04, 2
  #define	SR_RESERVED_17_5	0x17, 0x08, 3
  #define	SR_AACK_UPLD_RES_FT	0x17, 0x10, 4
  #define	SR_AACK_FLTR_RES_FT	0x17, 0x20, 5
  #define	SR_RESERVED_17_2	0x17, 0x40, 6
  #define	SR_RESERVED_17_1	0x17, 0x80, 7
  #define	RG_FTN_CTRL	(0x18)
  #define	SR_RESERVED_18_2	0x18, 0x7f, 0
  #define	SR_FTN_START		0x18, 0x80, 7
  #define	RG_PLL_CF	(0x1a)
  #define	SR_RESERVED_1a_2	0x1a, 0x7f, 0
  #define	SR_PLL_CF_START		0x1a, 0x80, 7
  #define	RG_PLL_DCU	(0x1b)
  #define	SR_RESERVED_1b_3	0x1b, 0x3f, 0
  #define	SR_RESERVED_1b_2	0x1b, 0x40, 6
  #define	SR_PLL_DCU_START	0x1b, 0x80, 7
  #define	RG_PART_NUM	(0x1c)
  #define	SR_PART_NUM		0x1c, 0xff, 0
  #define	RG_VERSION_NUM	(0x1d)
  #define	SR_VERSION_NUM		0x1d, 0xff, 0
  #define	RG_MAN_ID_0	(0x1e)
  #define	SR_MAN_ID_0		0x1e, 0xff, 0
  #define	RG_MAN_ID_1	(0x1f)
  #define	SR_MAN_ID_1		0x1f, 0xff, 0
  #define	RG_SHORT_ADDR_0	(0x20)
  #define	SR_SHORT_ADDR_0		0x20, 0xff, 0
  #define	RG_SHORT_ADDR_1	(0x21)
  #define	SR_SHORT_ADDR_1		0x21, 0xff, 0
  #define	RG_PAN_ID_0	(0x22)
  #define	SR_PAN_ID_0		0x22, 0xff, 0
  #define	RG_PAN_ID_1	(0x23)
  #define	SR_PAN_ID_1		0x23, 0xff, 0
  #define	RG_IEEE_ADDR_0	(0x24)
  #define	SR_IEEE_ADDR_0		0x24, 0xff, 0
  #define	RG_IEEE_ADDR_1	(0x25)
  #define	SR_IEEE_ADDR_1		0x25, 0xff, 0
  #define	RG_IEEE_ADDR_2	(0x26)
  #define	SR_IEEE_ADDR_2		0x26, 0xff, 0
  #define	RG_IEEE_ADDR_3	(0x27)
  #define	SR_IEEE_ADDR_3		0x27, 0xff, 0
  #define	RG_IEEE_ADDR_4	(0x28)
  #define	SR_IEEE_ADDR_4		0x28, 0xff, 0
  #define	RG_IEEE_ADDR_5	(0x29)
  #define	SR_IEEE_ADDR_5		0x29, 0xff, 0
  #define	RG_IEEE_ADDR_6	(0x2a)
  #define	SR_IEEE_ADDR_6		0x2a, 0xff, 0
  #define	RG_IEEE_ADDR_7	(0x2b)
  #define	SR_IEEE_ADDR_7		0x2b, 0xff, 0
  #define	RG_XAH_CTRL_0	(0x2c)
  #define	SR_SLOTTED_OPERATION	0x2c, 0x01, 0
  #define	SR_MAX_CSMA_RETRIES	0x2c, 0x0e, 1
  #define	SR_MAX_FRAME_RETRIES	0x2c, 0xf0, 4
  #define	RG_CSMA_SEED_0	(0x2d)
  #define	SR_CSMA_SEED_0		0x2d, 0xff, 0
  #define	RG_CSMA_SEED_1	(0x2e)
  #define	SR_CSMA_SEED_1		0x2e, 0x07, 0
  #define	SR_AACK_I_AM_COORD	0x2e, 0x08, 3
  #define	SR_AACK_DIS_ACK		0x2e, 0x10, 4
  #define	SR_AACK_SET_PD		0x2e, 0x20, 5
  #define	SR_AACK_FVN_MODE	0x2e, 0xc0, 6
  #define	RG_CSMA_BE	(0x2f)
  #define	SR_MIN_BE		0x2f, 0x0f, 0
  #define	SR_MAX_BE		0x2f, 0xf0, 4
  
  #define CMD_REG		0x80
  #define CMD_REG_MASK	0x3f
  #define CMD_WRITE	0x40
  #define CMD_FB		0x20
  
  #define IRQ_BAT_LOW	(1 << 7)
  #define IRQ_TRX_UR	(1 << 6)
  #define IRQ_AMI		(1 << 5)
  #define IRQ_CCA_ED	(1 << 4)
  #define IRQ_TRX_END	(1 << 3)
  #define IRQ_RX_START	(1 << 2)
  #define IRQ_PLL_UNL	(1 << 1)
  #define IRQ_PLL_LOCK	(1 << 0)
  
  #define IRQ_ACTIVE_HIGH	0
  #define IRQ_ACTIVE_LOW	1
  
  #define STATE_P_ON		0x00	/* BUSY */
  #define STATE_BUSY_RX		0x01
  #define STATE_BUSY_TX		0x02
  #define STATE_FORCE_TRX_OFF	0x03
  #define STATE_FORCE_TX_ON	0x04	/* IDLE */
  /* 0x05 */				/* INVALID_PARAMETER */
  #define STATE_RX_ON		0x06
  /* 0x07 */				/* SUCCESS */
  #define STATE_TRX_OFF		0x08
  #define STATE_TX_ON		0x09
  /* 0x0a - 0x0e */			/* 0x0a - UNSUPPORTED_ATTRIBUTE */
  #define STATE_SLEEP		0x0F
  #define STATE_BUSY_RX_AACK	0x11
  #define STATE_BUSY_TX_ARET	0x12
  #define STATE_RX_AACK_ON	0x16
  #define STATE_TX_ARET_ON	0x19
  #define STATE_RX_ON_NOCLK	0x1C
  #define STATE_RX_AACK_ON_NOCLK	0x1D
  #define STATE_BUSY_RX_AACK_NOCLK 0x1E
  #define STATE_TRANSITION_IN_PROGRESS 0x1F
  
  static int
  __at86rf230_write(struct at86rf230_local *lp, u8 addr, u8 data)
  {
  	u8 *buf = lp->buf;
  	int status;
  	struct spi_message msg;
  	struct spi_transfer xfer = {
  		.len	= 2,
  		.tx_buf	= buf,
  	};
  
  	buf[0] = (addr & CMD_REG_MASK) | CMD_REG | CMD_WRITE;
  	buf[1] = data;
  	dev_vdbg(&lp->spi->dev, "buf[0] = %02x
  ", buf[0]);
  	dev_vdbg(&lp->spi->dev, "buf[1] = %02x
  ", buf[1]);
  	spi_message_init(&msg);
  	spi_message_add_tail(&xfer, &msg);
  
  	status = spi_sync(lp->spi, &msg);
  	dev_vdbg(&lp->spi->dev, "status = %d
  ", status);
  	if (msg.status)
  		status = msg.status;
  
  	dev_vdbg(&lp->spi->dev, "status = %d
  ", status);
  	dev_vdbg(&lp->spi->dev, "buf[0] = %02x
  ", buf[0]);
  	dev_vdbg(&lp->spi->dev, "buf[1] = %02x
  ", buf[1]);
  
  	return status;
  }
  
  static int
  __at86rf230_read_subreg(struct at86rf230_local *lp,
  			u8 addr, u8 mask, int shift, u8 *data)
  {
  	u8 *buf = lp->buf;
  	int status;
  	struct spi_message msg;
  	struct spi_transfer xfer = {
  		.len	= 2,
  		.tx_buf	= buf,
  		.rx_buf	= buf,
  	};
  
  	buf[0] = (addr & CMD_REG_MASK) | CMD_REG;
  	buf[1] = 0xff;
  	dev_vdbg(&lp->spi->dev, "buf[0] = %02x
  ", buf[0]);
  	spi_message_init(&msg);
  	spi_message_add_tail(&xfer, &msg);
  
  	status = spi_sync(lp->spi, &msg);
  	dev_vdbg(&lp->spi->dev, "status = %d
  ", status);
  	if (msg.status)
  		status = msg.status;
  
  	dev_vdbg(&lp->spi->dev, "status = %d
  ", status);
  	dev_vdbg(&lp->spi->dev, "buf[0] = %02x
  ", buf[0]);
  	dev_vdbg(&lp->spi->dev, "buf[1] = %02x
  ", buf[1]);
  
  	if (status == 0)
  		*data = buf[1];
  
  	return status;
  }
  
  static int
  at86rf230_read_subreg(struct at86rf230_local *lp,
  		      u8 addr, u8 mask, int shift, u8 *data)
  {
  	int status;
  
  	mutex_lock(&lp->bmux);
  	status = __at86rf230_read_subreg(lp, addr, mask, shift, data);
  	mutex_unlock(&lp->bmux);
  
  	return status;
  }
  
  static int
  at86rf230_write_subreg(struct at86rf230_local *lp,
  		       u8 addr, u8 mask, int shift, u8 data)
  {
  	int status;
  	u8 val;
  
  	mutex_lock(&lp->bmux);
  	status = __at86rf230_read_subreg(lp, addr, 0xff, 0, &val);
  	if (status)
  		goto out;
  
  	val &= ~mask;
  	val |= (data << shift) & mask;
  
  	status = __at86rf230_write(lp, addr, val);
  out:
  	mutex_unlock(&lp->bmux);
  
  	return status;
  }
  
  static int
  at86rf230_write_fbuf(struct at86rf230_local *lp, u8 *data, u8 len)
  {
  	u8 *buf = lp->buf;
  	int status;
  	struct spi_message msg;
  	struct spi_transfer xfer_head = {
  		.len		= 2,
  		.tx_buf		= buf,
  
  	};
  	struct spi_transfer xfer_buf = {
  		.len		= len,
  		.tx_buf		= data,
  	};
  
  	mutex_lock(&lp->bmux);
  	buf[0] = CMD_WRITE | CMD_FB;
  	buf[1] = len + 2; /* 2 bytes for CRC that isn't written */
  
  	dev_vdbg(&lp->spi->dev, "buf[0] = %02x
  ", buf[0]);
  	dev_vdbg(&lp->spi->dev, "buf[1] = %02x
  ", buf[1]);
  
  	spi_message_init(&msg);
  	spi_message_add_tail(&xfer_head, &msg);
  	spi_message_add_tail(&xfer_buf, &msg);
  
  	status = spi_sync(lp->spi, &msg);
  	dev_vdbg(&lp->spi->dev, "status = %d
  ", status);
  	if (msg.status)
  		status = msg.status;
  
  	dev_vdbg(&lp->spi->dev, "status = %d
  ", status);
  	dev_vdbg(&lp->spi->dev, "buf[0] = %02x
  ", buf[0]);
  	dev_vdbg(&lp->spi->dev, "buf[1] = %02x
  ", buf[1]);
  
  	mutex_unlock(&lp->bmux);
  	return status;
  }
  
  static int
  at86rf230_read_fbuf(struct at86rf230_local *lp, u8 *data, u8 *len, u8 *lqi)
  {
  	u8 *buf = lp->buf;
  	int status;
  	struct spi_message msg;
  	struct spi_transfer xfer_head = {
  		.len		= 2,
  		.tx_buf		= buf,
  		.rx_buf		= buf,
  	};
  	struct spi_transfer xfer_head1 = {
  		.len		= 2,
  		.tx_buf		= buf,
  		.rx_buf		= buf,
  	};
  	struct spi_transfer xfer_buf = {
  		.len		= 0,
  		.rx_buf		= data,
  	};
  
  	mutex_lock(&lp->bmux);
  
  	buf[0] = CMD_FB;
  	buf[1] = 0x00;
  
  	spi_message_init(&msg);
  	spi_message_add_tail(&xfer_head, &msg);
  
  	status = spi_sync(lp->spi, &msg);
  	dev_vdbg(&lp->spi->dev, "status = %d
  ", status);
  
  	xfer_buf.len = *(buf + 1) + 1;
  	*len = buf[1];
  
  	buf[0] = CMD_FB;
  	buf[1] = 0x00;
  
  	spi_message_init(&msg);
  	spi_message_add_tail(&xfer_head1, &msg);
  	spi_message_add_tail(&xfer_buf, &msg);
  
  	status = spi_sync(lp->spi, &msg);
  
  	if (msg.status)
  		status = msg.status;
  
  	dev_vdbg(&lp->spi->dev, "status = %d
  ", status);
  	dev_vdbg(&lp->spi->dev, "buf[0] = %02x
  ", buf[0]);
  	dev_vdbg(&lp->spi->dev, "buf[1] = %02x
  ", buf[1]);
  
  	if (status) {
  		if (lqi && (*len > lp->buf[1]))
  			*lqi = data[lp->buf[1]];
  	}
  	mutex_unlock(&lp->bmux);
  
  	return status;
  }
  
  static int
  at86rf230_ed(struct ieee802154_dev *dev, u8 *level)
  {
  	might_sleep();
  	BUG_ON(!level);
  	*level = 0xbe;
  	return 0;
  }
  
  static int
  at86rf230_state(struct ieee802154_dev *dev, int state)
  {
  	struct at86rf230_local *lp = dev->priv;
  	int rc;
  	u8 val;
  	u8 desired_status;
  
  	might_sleep();
  
  	if (state == STATE_FORCE_TX_ON)
  		desired_status = STATE_TX_ON;
  	else if (state == STATE_FORCE_TRX_OFF)
  		desired_status = STATE_TRX_OFF;
  	else
  		desired_status = state;
  
  	do {
  		rc = at86rf230_read_subreg(lp, SR_TRX_STATUS, &val);
  		if (rc)
  			goto err;
  	} while (val == STATE_TRANSITION_IN_PROGRESS);
  
  	if (val == desired_status)
  		return 0;
  
  	/* state is equal to phy states */
  	rc = at86rf230_write_subreg(lp, SR_TRX_CMD, state);
  	if (rc)
  		goto err;
  
  	do {
  		rc = at86rf230_read_subreg(lp, SR_TRX_STATUS, &val);
  		if (rc)
  			goto err;
  	} while (val == STATE_TRANSITION_IN_PROGRESS);
  
  
  	if (val == desired_status)
  		return 0;
  
  	pr_err("unexpected state change: %d, asked for %d
  ", val, state);
  	return -EBUSY;
  
  err:
  	pr_err("error: %d
  ", rc);
  	return rc;
  }
  
  static int
  at86rf230_start(struct ieee802154_dev *dev)
  {
  	struct at86rf230_local *lp = dev->priv;
  	u8 rc;
  
  	rc = at86rf230_write_subreg(lp, SR_RX_SAFE_MODE, 1);
  	if (rc)
  		return rc;
  
  	return at86rf230_state(dev, STATE_RX_ON);
  }
  
  static void
  at86rf230_stop(struct ieee802154_dev *dev)
  {
  	at86rf230_state(dev, STATE_FORCE_TRX_OFF);
  }
  
  static int
  at86rf230_channel(struct ieee802154_dev *dev, int page, int channel)
  {
  	struct at86rf230_local *lp = dev->priv;
  	int rc;
  
  	might_sleep();
  
  	if (page != 0 || channel < 11 || channel > 26) {
  		WARN_ON(1);
  		return -EINVAL;
  	}
  
  	rc = at86rf230_write_subreg(lp, SR_CHANNEL, channel);
  	msleep(1); /* Wait for PLL */
  	dev->phy->current_channel = channel;
  
  	return 0;
  }
  
  static int
  at86rf230_xmit(struct ieee802154_dev *dev, struct sk_buff *skb)
  {
  	struct at86rf230_local *lp = dev->priv;
  	int rc;
  	unsigned long flags;
  
  	spin_lock_irqsave(&lp->lock, flags);
  	if  (lp->irq_busy) {
  		spin_unlock_irqrestore(&lp->lock, flags);
  		return -EBUSY;
  	}
  	spin_unlock_irqrestore(&lp->lock, flags);
  
  	might_sleep();
  
  	rc = at86rf230_state(dev, STATE_FORCE_TX_ON);
  	if (rc)
  		goto err;
  
  	spin_lock_irqsave(&lp->lock, flags);
  	lp->is_tx = 1;
  	reinit_completion(&lp->tx_complete);
  	spin_unlock_irqrestore(&lp->lock, flags);
  
  	rc = at86rf230_write_fbuf(lp, skb->data, skb->len);
  	if (rc)
  		goto err_rx;
  
  	rc = at86rf230_write_subreg(lp, SR_TRX_CMD, STATE_BUSY_TX);
  	if (rc)
  		goto err_rx;
  
  	rc = wait_for_completion_interruptible(&lp->tx_complete);
  	if (rc < 0)
  		goto err_rx;
  
  	rc = at86rf230_start(dev);
  
  	return rc;
  
  err_rx:
  	at86rf230_start(dev);
  err:
  	pr_err("error: %d
  ", rc);
  
  	spin_lock_irqsave(&lp->lock, flags);
  	lp->is_tx = 0;
  	spin_unlock_irqrestore(&lp->lock, flags);
  
  	return rc;
  }
  
  static int at86rf230_rx(struct at86rf230_local *lp)
  {
  	u8 len = 128, lqi = 0;
  	struct sk_buff *skb;
  
  	skb = alloc_skb(len, GFP_KERNEL);
  
  	if (!skb)
  		return -ENOMEM;
  
  	if (at86rf230_read_fbuf(lp, skb_put(skb, len), &len, &lqi))
  		goto err;
  
  	if (len < 2)
  		goto err;
  
  	skb_trim(skb, len - 2); /* We do not put CRC into the frame */
  
  	ieee802154_rx_irqsafe(lp->dev, skb, lqi);
  
  	dev_dbg(&lp->spi->dev, "READ_FBUF: %d %x
  ", len, lqi);
  
  	return 0;
  err:
  	pr_debug("received frame is too small
  ");
  
  	kfree_skb(skb);
  	return -EINVAL;
  }
  
  static int
  at86rf230_set_hw_addr_filt(struct ieee802154_dev *dev,
  			   struct ieee802154_hw_addr_filt *filt,
  			   unsigned long changed)
  {
  	struct at86rf230_local *lp = dev->priv;
  
  	if (changed & IEEE802515_AFILT_SADDR_CHANGED) {
  		dev_vdbg(&lp->spi->dev,
  			"at86rf230_set_hw_addr_filt called for saddr
  ");
  		__at86rf230_write(lp, RG_SHORT_ADDR_0, filt->short_addr);
  		__at86rf230_write(lp, RG_SHORT_ADDR_1, filt->short_addr >> 8);
  	}
  
  	if (changed & IEEE802515_AFILT_PANID_CHANGED) {
  		dev_vdbg(&lp->spi->dev,
  			"at86rf230_set_hw_addr_filt called for pan id
  ");
  		__at86rf230_write(lp, RG_PAN_ID_0, filt->pan_id);
  		__at86rf230_write(lp, RG_PAN_ID_1, filt->pan_id >> 8);
  	}
  
  	if (changed & IEEE802515_AFILT_IEEEADDR_CHANGED) {
  		dev_vdbg(&lp->spi->dev,
  			"at86rf230_set_hw_addr_filt called for IEEE addr
  ");
  		at86rf230_write_subreg(lp, SR_IEEE_ADDR_0, filt->ieee_addr[7]);
  		at86rf230_write_subreg(lp, SR_IEEE_ADDR_1, filt->ieee_addr[6]);
  		at86rf230_write_subreg(lp, SR_IEEE_ADDR_2, filt->ieee_addr[5]);
  		at86rf230_write_subreg(lp, SR_IEEE_ADDR_3, filt->ieee_addr[4]);
  		at86rf230_write_subreg(lp, SR_IEEE_ADDR_4, filt->ieee_addr[3]);
  		at86rf230_write_subreg(lp, SR_IEEE_ADDR_5, filt->ieee_addr[2]);
  		at86rf230_write_subreg(lp, SR_IEEE_ADDR_6, filt->ieee_addr[1]);
  		at86rf230_write_subreg(lp, SR_IEEE_ADDR_7, filt->ieee_addr[0]);
  	}
  
  	if (changed & IEEE802515_AFILT_PANC_CHANGED) {
  		dev_vdbg(&lp->spi->dev,
  			"at86rf230_set_hw_addr_filt called for panc change
  ");
  		if (filt->pan_coord)
  			at86rf230_write_subreg(lp, SR_AACK_I_AM_COORD, 1);
  		else
  			at86rf230_write_subreg(lp, SR_AACK_I_AM_COORD, 0);
  	}
  
  	return 0;
  }
  
  static struct ieee802154_ops at86rf230_ops = {
  	.owner = THIS_MODULE,
  	.xmit = at86rf230_xmit,
  	.ed = at86rf230_ed,
  	.set_channel = at86rf230_channel,
  	.start = at86rf230_start,
  	.stop = at86rf230_stop,
  	.set_hw_addr_filt = at86rf230_set_hw_addr_filt,
  };
  
  static void at86rf230_irqwork(struct work_struct *work)
  {
  	struct at86rf230_local *lp =
  		container_of(work, struct at86rf230_local, irqwork);
  	u8 status = 0, val;
  	int rc;
  	unsigned long flags;
  
  	rc = at86rf230_read_subreg(lp, RG_IRQ_STATUS, 0xff, 0, &val);
  	status |= val;
  
  	status &= ~IRQ_PLL_LOCK; /* ignore */
  	status &= ~IRQ_RX_START; /* ignore */
  	status &= ~IRQ_AMI; /* ignore */
  	status &= ~IRQ_TRX_UR; /* FIXME: possibly handle ???*/
  
  	if (status & IRQ_TRX_END) {
  		spin_lock_irqsave(&lp->lock, flags);
  		status &= ~IRQ_TRX_END;
  		if (lp->is_tx) {
  			lp->is_tx = 0;
  			spin_unlock_irqrestore(&lp->lock, flags);
  			complete(&lp->tx_complete);
  		} else {
  			spin_unlock_irqrestore(&lp->lock, flags);
  			at86rf230_rx(lp);
  		}
  	}
  
  	spin_lock_irqsave(&lp->lock, flags);
  	lp->irq_busy = 0;
  	spin_unlock_irqrestore(&lp->lock, flags);
  }
  
  static void at86rf230_irqwork_level(struct work_struct *work)
  {
  	struct at86rf230_local *lp =
  		container_of(work, struct at86rf230_local, irqwork);
  
  	at86rf230_irqwork(work);
  
  	enable_irq(lp->spi->irq);
  }
  
  static irqreturn_t at86rf230_isr(int irq, void *data)
  {
  	struct at86rf230_local *lp = data;
  	unsigned long flags;
  
  	spin_lock_irqsave(&lp->lock, flags);
  	lp->irq_busy = 1;
  	spin_unlock_irqrestore(&lp->lock, flags);
  
  	schedule_work(&lp->irqwork);
  
  	return IRQ_HANDLED;
  }
  
  static irqreturn_t at86rf230_isr_level(int irq, void *data)
  {
  	disable_irq_nosync(irq);
  
  	return at86rf230_isr(irq, data);
  }
  
  static int at86rf230_irq_polarity(struct at86rf230_local *lp, int pol)
  {
  	return at86rf230_write_subreg(lp, SR_IRQ_POLARITY, pol);
  }
  
  static int at86rf230_hw_init(struct at86rf230_local *lp)
  {
  	struct at86rf230_platform_data *pdata = lp->spi->dev.platform_data;
  	int rc, irq_pol;
  	u8 status;
  
  	rc = at86rf230_read_subreg(lp, SR_TRX_STATUS, &status);
  	if (rc)
  		return rc;
  
  	dev_info(&lp->spi->dev, "Status: %02x
  ", status);
  	if (status == STATE_P_ON) {
  		rc = at86rf230_write_subreg(lp, SR_TRX_CMD, STATE_TRX_OFF);
  		if (rc)
  			return rc;
  		msleep(1);
  		rc = at86rf230_read_subreg(lp, SR_TRX_STATUS, &status);
  		if (rc)
  			return rc;
  		dev_info(&lp->spi->dev, "Status: %02x
  ", status);
  	}
  
  	/* configure irq polarity, defaults to high active */
  	if (pdata->irq_type & (IRQF_TRIGGER_FALLING | IRQF_TRIGGER_LOW))
  		irq_pol = IRQ_ACTIVE_LOW;
  	else
  		irq_pol = IRQ_ACTIVE_HIGH;
  
  	rc = at86rf230_irq_polarity(lp, irq_pol);
  	if (rc)
  		return rc;
  
  	rc = at86rf230_write_subreg(lp, SR_IRQ_MASK, IRQ_TRX_END);
  	if (rc)
  		return rc;
  
  	/* CLKM changes are applied immediately */
  	rc = at86rf230_write_subreg(lp, SR_CLKM_SHA_SEL, 0x00);
  	if (rc)
  		return rc;
  
  	/* Turn CLKM Off */
  	rc = at86rf230_write_subreg(lp, SR_CLKM_CTRL, 0x00);
  	if (rc)
  		return rc;
  	/* Wait the next SLEEP cycle */
  	msleep(100);
  
  	rc = at86rf230_write_subreg(lp, SR_TRX_CMD, STATE_TX_ON);
  	if (rc)
  		return rc;
  	msleep(1);
  
  	rc = at86rf230_read_subreg(lp, SR_TRX_STATUS, &status);
  	if (rc)
  		return rc;
  	dev_info(&lp->spi->dev, "Status: %02x
  ", status);
  
  	rc = at86rf230_read_subreg(lp, SR_DVDD_OK, &status);
  	if (rc)
  		return rc;
  	if (!status) {
  		dev_err(&lp->spi->dev, "DVDD error
  ");
  		return -EINVAL;
  	}
  
  	rc = at86rf230_read_subreg(lp, SR_AVDD_OK, &status);
  	if (rc)
  		return rc;
  	if (!status) {
  		dev_err(&lp->spi->dev, "AVDD error
  ");
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  static void at86rf230_fill_data(struct spi_device *spi)
  {
  	struct at86rf230_local *lp = spi_get_drvdata(spi);
  	struct at86rf230_platform_data *pdata = spi->dev.platform_data;
  
  	lp->rstn = pdata->rstn;
  	lp->slp_tr = pdata->slp_tr;
  	lp->dig2 = pdata->dig2;
  }
  
  static int at86rf230_probe(struct spi_device *spi)
  {
  	struct at86rf230_platform_data *pdata;
  	struct ieee802154_dev *dev;
  	struct at86rf230_local *lp;
  	u8 man_id_0, man_id_1, status;
  	irq_handler_t irq_handler;
  	work_func_t irq_worker;
  	int rc, supported = 0;
  	const char *chip;
  
  	if (!spi->irq) {
  		dev_err(&spi->dev, "no IRQ specified
  ");
  		return -EINVAL;
  	}
  
  	pdata = spi->dev.platform_data;
  	if (!pdata) {
  		dev_err(&spi->dev, "no platform_data
  ");
  		return -EINVAL;
  	}
  
  	dev = ieee802154_alloc_device(sizeof(*lp), &at86rf230_ops);
  	if (!dev)
  		return -ENOMEM;
  
  	lp = dev->priv;
  	lp->dev = dev;
  
  	lp->spi = spi;
  
  	dev->parent = &spi->dev;
  	dev->extra_tx_headroom = 0;
  	/* We do support only 2.4 Ghz */
  	dev->phy->channels_supported[0] = 0x7FFF800;
  	dev->flags = IEEE802154_HW_OMIT_CKSUM;
  
  	if (pdata->irq_type & (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)) {
  		irq_worker = at86rf230_irqwork;
  		irq_handler = at86rf230_isr;
  	} else {
  		irq_worker = at86rf230_irqwork_level;
  		irq_handler = at86rf230_isr_level;
  	}
  
  	mutex_init(&lp->bmux);
  	INIT_WORK(&lp->irqwork, irq_worker);
  	spin_lock_init(&lp->lock);
  	init_completion(&lp->tx_complete);
  
  	spi_set_drvdata(spi, lp);
  
  	at86rf230_fill_data(spi);
  
  	rc = gpio_request(lp->rstn, "rstn");
  	if (rc)
  		goto err_rstn;
  
  	if (gpio_is_valid(lp->slp_tr)) {
  		rc = gpio_request(lp->slp_tr, "slp_tr");
  		if (rc)
  			goto err_slp_tr;
  	}
  
  	rc = gpio_direction_output(lp->rstn, 1);
  	if (rc)
  		goto err_gpio_dir;
  
  	if (gpio_is_valid(lp->slp_tr)) {
  		rc = gpio_direction_output(lp->slp_tr, 0);
  		if (rc)
  			goto err_gpio_dir;
  	}
  
  	/* Reset */
  	msleep(1);
  	gpio_set_value(lp->rstn, 0);
  	msleep(1);
  	gpio_set_value(lp->rstn, 1);
  	msleep(1);
  
  	rc = at86rf230_read_subreg(lp, SR_MAN_ID_0, &man_id_0);
  	if (rc)
  		goto err_gpio_dir;
  	rc = at86rf230_read_subreg(lp, SR_MAN_ID_1, &man_id_1);
  	if (rc)
  		goto err_gpio_dir;
  
  	if (man_id_1 != 0x00 || man_id_0 != 0x1f) {
  		dev_err(&spi->dev, "Non-Atmel dev found (MAN_ID %02x %02x)
  ",
  			man_id_1, man_id_0);
  		rc = -EINVAL;
  		goto err_gpio_dir;
  	}
  
  	rc = at86rf230_read_subreg(lp, SR_PART_NUM, &lp->part);
  	if (rc)
  		goto err_gpio_dir;
  
  	rc = at86rf230_read_subreg(lp, SR_VERSION_NUM, &lp->vers);
  	if (rc)
  		goto err_gpio_dir;
  
  	switch (lp->part) {
  	case 2:
  		chip = "at86rf230";
  		/* supported = 1;  FIXME: should be easy to support; */
  		break;
  	case 3:
  		chip = "at86rf231";
  		supported = 1;
  		break;
  	default:
  		chip = "UNKNOWN";
  		break;
  	}
  
  	dev_info(&spi->dev, "Detected %s chip version %d
  ", chip, lp->vers);
  	if (!supported) {
  		rc = -ENOTSUPP;
  		goto err_gpio_dir;
  	}
  
  	rc = at86rf230_hw_init(lp);
  	if (rc)
  		goto err_gpio_dir;
  
  	rc = request_irq(spi->irq, irq_handler,
  			 IRQF_SHARED | pdata->irq_type,
  			 dev_name(&spi->dev), lp);
  	if (rc)
  		goto err_gpio_dir;
  
  	/* Read irq status register to reset irq line */
  	rc = at86rf230_read_subreg(lp, RG_IRQ_STATUS, 0xff, 0, &status);
  	if (rc)
  		goto err_irq;
  
  	rc = ieee802154_register_device(lp->dev);
  	if (rc)
  		goto err_irq;
  
  	return rc;
  
  err_irq:
  	free_irq(spi->irq, lp);
  	flush_work(&lp->irqwork);
  err_gpio_dir:
  	if (gpio_is_valid(lp->slp_tr))
  		gpio_free(lp->slp_tr);
  err_slp_tr:
  	gpio_free(lp->rstn);
  err_rstn:
  	mutex_destroy(&lp->bmux);
  	ieee802154_free_device(lp->dev);
  	return rc;
  }
  
  static int at86rf230_remove(struct spi_device *spi)
  {
  	struct at86rf230_local *lp = spi_get_drvdata(spi);
  
  	ieee802154_unregister_device(lp->dev);
  
  	free_irq(spi->irq, lp);
  	flush_work(&lp->irqwork);
  
  	if (gpio_is_valid(lp->slp_tr))
  		gpio_free(lp->slp_tr);
  	gpio_free(lp->rstn);
  
  	mutex_destroy(&lp->bmux);
  	ieee802154_free_device(lp->dev);
  
  	dev_dbg(&spi->dev, "unregistered at86rf230
  ");
  	return 0;
  }
  
  static struct spi_driver at86rf230_driver = {
  	.driver = {
  		.name	= "at86rf230",
  		.owner	= THIS_MODULE,
  	},
  	.probe      = at86rf230_probe,
  	.remove     = at86rf230_remove,
  };
  
  module_spi_driver(at86rf230_driver);
  
  MODULE_DESCRIPTION("AT86RF230 Transceiver Driver");
  MODULE_LICENSE("GPL v2");