// SPDX-License-Identifier: GPL-2.0-only
/*
 * AT86RF230/RF231 driver
 *
 * Copyright (C) 2009-2012 Siemens AG
 *
 * Written by:
 * Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
 * Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
 * Alexander Aring <aar@pengutronix.de>
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/gpio/consumer.h>
#include <linux/hrtimer.h>
#include <linux/jiffies.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/delay.h>
#include <linux/property.h>
#include <linux/spi/spi.h>
#include <linux/regmap.h>
#include <linux/skbuff.h>
#include <linux/ieee802154.h>

#include <net/mac802154.h>
#include <net/cfg802154.h>

#include "at86rf230.h"

struct at86rf230_local;
/* at86rf2xx chip depend data.
 * All timings are in us.
 */
struct at86rf2xx_chip_data {
        u16 t_sleep_cycle;
        u16 t_channel_switch;
        u16 t_reset_to_off;
        u16 t_off_to_aack;
        u16 t_off_to_tx_on;
        u16 t_off_to_sleep;
        u16 t_sleep_to_off;
        u16 t_frame;
        u16 t_p_ack;
        int rssi_base_val;

        int (*set_channel)(struct at86rf230_local *, u8, u8);
        int (*set_txpower)(struct at86rf230_local *, s32);
};

#define AT86RF2XX_MAX_BUF               (127 + 3)
/* tx retries to access the TX_ON state
 * if it's above then force change will be started.
 *
 * We assume the max_frame_retries (7) value of 802.15.4 here.
 */
#define AT86RF2XX_MAX_TX_RETRIES        7
/* We use the recommended 5 minutes timeout to recalibrate */
#define AT86RF2XX_CAL_LOOP_TIMEOUT      (5 * 60 * HZ)

struct at86rf230_state_change {
        struct at86rf230_local *lp;
        int irq;

        struct hrtimer timer;
        struct spi_message msg;
        struct spi_transfer trx;
        u8 buf[AT86RF2XX_MAX_BUF];

        void (*complete)(void *context);
        u8 from_state;
        u8 to_state;
        int trac;

        bool free;
};

struct at86rf230_local {
        struct spi_device *spi;

        struct ieee802154_hw *hw;
        struct at86rf2xx_chip_data *data;
        struct regmap *regmap;
        struct gpio_desc *slp_tr;
        bool sleep;

        struct completion state_complete;
        struct at86rf230_state_change state;

        unsigned long cal_timeout;
        bool is_tx;
        bool is_tx_from_off;
        bool was_tx;
        u8 tx_retry;
        struct sk_buff *tx_skb;
        struct at86rf230_state_change tx;
};

#define AT86RF2XX_NUMREGS 0x3F

static void
at86rf230_async_state_change(struct at86rf230_local *lp,
                             struct at86rf230_state_change *ctx,
                             const u8 state, void (*complete)(void *context));

static inline void
at86rf230_sleep(struct at86rf230_local *lp)
{
        if (lp->slp_tr) {
                gpiod_set_value(lp->slp_tr, 1);
                usleep_range(lp->data->t_off_to_sleep,
                             lp->data->t_off_to_sleep + 10);
                lp->sleep = true;
        }
}

static inline void
at86rf230_awake(struct at86rf230_local *lp)
{
        if (lp->slp_tr) {
                gpiod_set_value(lp->slp_tr, 0);
                usleep_range(lp->data->t_sleep_to_off,
                             lp->data->t_sleep_to_off + 100);
                lp->sleep = false;
        }
}

static inline int
__at86rf230_write(struct at86rf230_local *lp,
                  unsigned int addr, unsigned int data)
{
        bool sleep = lp->sleep;
        int ret;

        /* awake for register setting if sleep */
        if (sleep)
                at86rf230_awake(lp);

        ret = regmap_write(lp->regmap, addr, data);

        /* sleep again if was sleeping */
        if (sleep)
                at86rf230_sleep(lp);

        return ret;
}

static inline int
__at86rf230_read(struct at86rf230_local *lp,
                 unsigned int addr, unsigned int *data)
{
        bool sleep = lp->sleep;
        int ret;

        /* awake for register setting if sleep */
        if (sleep)
                at86rf230_awake(lp);

        ret = regmap_read(lp->regmap, addr, data);

        /* sleep again if was sleeping */
        if (sleep)
                at86rf230_sleep(lp);

        return ret;
}

static inline int
at86rf230_read_subreg(struct at86rf230_local *lp,
                      unsigned int addr, unsigned int mask,
                      unsigned int shift, unsigned int *data)
{
        int rc;

        rc = __at86rf230_read(lp, addr, data);
        if (!rc)
                *data = (*data & mask) >> shift;

        return rc;
}

static inline int
at86rf230_write_subreg(struct at86rf230_local *lp,
                       unsigned int addr, unsigned int mask,
                       unsigned int shift, unsigned int data)
{
        bool sleep = lp->sleep;
        int ret;

        /* awake for register setting if sleep */
        if (sleep)
                at86rf230_awake(lp);

        ret = regmap_update_bits(lp->regmap, addr, mask, data << shift);

        /* sleep again if was sleeping */
        if (sleep)
                at86rf230_sleep(lp);

        return ret;
}

static inline void
at86rf230_slp_tr_rising_edge(struct at86rf230_local *lp)
{
        gpiod_set_value(lp->slp_tr, 1);
        udelay(1);
        gpiod_set_value(lp->slp_tr, 0);
}

static bool
at86rf230_reg_writeable(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case RG_TRX_STATE:
        case RG_TRX_CTRL_0:
        case RG_TRX_CTRL_1:
        case RG_PHY_TX_PWR:
        case RG_PHY_ED_LEVEL:
        case RG_PHY_CC_CCA:
        case RG_CCA_THRES:
        case RG_RX_CTRL:
        case RG_SFD_VALUE:
        case RG_TRX_CTRL_2:
        case RG_ANT_DIV:
        case RG_IRQ_MASK:
        case RG_VREG_CTRL:
        case RG_BATMON:
        case RG_XOSC_CTRL:
        case RG_RX_SYN:
        case RG_XAH_CTRL_1:
        case RG_FTN_CTRL:
        case RG_PLL_CF:
        case RG_PLL_DCU:
        case RG_SHORT_ADDR_0:
        case RG_SHORT_ADDR_1:
        case RG_PAN_ID_0:
        case RG_PAN_ID_1:
        case RG_IEEE_ADDR_0:
        case RG_IEEE_ADDR_1:
        case RG_IEEE_ADDR_2:
        case RG_IEEE_ADDR_3:
        case RG_IEEE_ADDR_4:
        case RG_IEEE_ADDR_5:
        case RG_IEEE_ADDR_6:
        case RG_IEEE_ADDR_7:
        case RG_XAH_CTRL_0:
        case RG_CSMA_SEED_0:
        case RG_CSMA_SEED_1:
        case RG_CSMA_BE:
                return true;
        default:
                return false;
        }
}

static bool
at86rf230_reg_readable(struct device *dev, unsigned int reg)
{
        bool rc;

        /* all writeable are also readable */
        rc = at86rf230_reg_writeable(dev, reg);
        if (rc)
                return rc;

        /* readonly regs */
        switch (reg) {
        case RG_TRX_STATUS:
        case RG_PHY_RSSI:
        case RG_IRQ_STATUS:
        case RG_PART_NUM:
        case RG_VERSION_NUM:
        case RG_MAN_ID_1:
        case RG_MAN_ID_0:
                return true;
        default:
                return false;
        }
}

static bool
at86rf230_reg_volatile(struct device *dev, unsigned int reg)
{
        /* can be changed during runtime */
        switch (reg) {
        case RG_TRX_STATUS:
        case RG_TRX_STATE:
        case RG_PHY_RSSI:
        case RG_PHY_ED_LEVEL:
        case RG_IRQ_STATUS:
        case RG_VREG_CTRL:
        case RG_PLL_CF:
        case RG_PLL_DCU:
                return true;
        default:
                return false;
        }
}

static bool
at86rf230_reg_precious(struct device *dev, unsigned int reg)
{
        /* don't clear irq line on read */
        switch (reg) {
        case RG_IRQ_STATUS:
                return true;
        default:
                return false;
        }
}

static const struct regmap_config at86rf230_regmap_spi_config = {
        .reg_bits = 8,
        .val_bits = 8,
        .write_flag_mask = CMD_REG | CMD_WRITE,
        .read_flag_mask = CMD_REG,
        .cache_type = REGCACHE_MAPLE,
        .max_register = AT86RF2XX_NUMREGS,
        .writeable_reg = at86rf230_reg_writeable,
        .readable_reg = at86rf230_reg_readable,
        .volatile_reg = at86rf230_reg_volatile,
        .precious_reg = at86rf230_reg_precious,
};

static void
at86rf230_async_error_recover_complete(void *context)
{
        struct at86rf230_state_change *ctx = context;
        struct at86rf230_local *lp = ctx->lp;

        if (ctx->free)
                kfree(ctx);

        if (lp->was_tx) {
                lp->was_tx = 0;
                ieee802154_xmit_hw_error(lp->hw, lp->tx_skb);
        }
}

static void
at86rf230_async_error_recover(void *context)
{
        struct at86rf230_state_change *ctx = context;
        struct at86rf230_local *lp = ctx->lp;

        if (lp->is_tx) {
                lp->was_tx = 1;
                lp->is_tx = 0;
        }

        at86rf230_async_state_change(lp, ctx, STATE_RX_AACK_ON,
                                     at86rf230_async_error_recover_complete);
}

static inline void
at86rf230_async_error(struct at86rf230_local *lp,
                      struct at86rf230_state_change *ctx, int rc)
{
        dev_err(&lp->spi->dev, "spi_async error %d\n", rc);

        at86rf230_async_state_change(lp, ctx, STATE_FORCE_TRX_OFF,
                                     at86rf230_async_error_recover);
}

/* Generic function to get some register value in async mode */
static void
at86rf230_async_read_reg(struct at86rf230_local *lp, u8 reg,
                         struct at86rf230_state_change *ctx,
                         void (*complete)(void *context))
{
        int rc;

        u8 *tx_buf = ctx->buf;

        tx_buf[0] = (reg & CMD_REG_MASK) | CMD_REG;
        ctx->msg.complete = complete;
        rc = spi_async(lp->spi, &ctx->msg);
        if (rc)
                at86rf230_async_error(lp, ctx, rc);
}

static void
at86rf230_async_write_reg(struct at86rf230_local *lp, u8 reg, u8 val,
                          struct at86rf230_state_change *ctx,
                          void (*complete)(void *context))
{
        int rc;

        ctx->buf[0] = (reg & CMD_REG_MASK) | CMD_REG | CMD_WRITE;
        ctx->buf[1] = val;
        ctx->msg.complete = complete;
        rc = spi_async(lp->spi, &ctx->msg);
        if (rc)
                at86rf230_async_error(lp, ctx, rc);
}

static void
at86rf230_async_state_assert(void *context)
{
        struct at86rf230_state_change *ctx = context;
        struct at86rf230_local *lp = ctx->lp;
        const u8 *buf = ctx->buf;
        const u8 trx_state = buf[1] & TRX_STATE_MASK;

        /* Assert state change */
        if (trx_state != ctx->to_state) {
                /* Special handling if transceiver state is in
                 * STATE_BUSY_RX_AACK and a SHR was detected.
                 */
                if  (trx_state == STATE_BUSY_RX_AACK) {
                        /* Undocumented race condition. If we send a state
                         * change to STATE_RX_AACK_ON the transceiver could
                         * change his state automatically to STATE_BUSY_RX_AACK
                         * if a SHR was detected. This is not an error, but we
                         * can't assert this.
                         */
                        if (ctx->to_state == STATE_RX_AACK_ON)
                                goto done;

                        /* If we change to STATE_TX_ON without forcing and
                         * transceiver state is STATE_BUSY_RX_AACK, we wait
                         * 'tFrame + tPAck' receiving time. In this time the
                         * PDU should be received. If the transceiver is still
                         * in STATE_BUSY_RX_AACK, we run a force state change
                         * to STATE_TX_ON. This is a timeout handling, if the
                         * transceiver stucks in STATE_BUSY_RX_AACK.
                         *
                         * Additional we do several retries to try to get into
                         * TX_ON state without forcing. If the retries are
                         * higher or equal than AT86RF2XX_MAX_TX_RETRIES we
                         * will do a force change.
                         */
                        if (ctx->to_state == STATE_TX_ON ||
                            ctx->to_state == STATE_TRX_OFF) {
                                u8 state = ctx->to_state;

                                if (lp->tx_retry >= AT86RF2XX_MAX_TX_RETRIES)
                                        state = STATE_FORCE_TRX_OFF;
                                lp->tx_retry++;

                                at86rf230_async_state_change(lp, ctx, state,
                                                             ctx->complete);
                                return;
                        }
                }

                dev_warn(&lp->spi->dev, "unexcept state change from 0x%02x to 0x%02x. Actual state: 0x%02x\n",
                         ctx->from_state, ctx->to_state, trx_state);
        }

done:
        if (ctx->complete)
                ctx->complete(context);
}

static enum hrtimer_restart at86rf230_async_state_timer(struct hrtimer *timer)
{
        struct at86rf230_state_change *ctx =
                container_of(timer, struct at86rf230_state_change, timer);
        struct at86rf230_local *lp = ctx->lp;

        at86rf230_async_read_reg(lp, RG_TRX_STATUS, ctx,
                                 at86rf230_async_state_assert);

        return HRTIMER_NORESTART;
}

/* Do state change timing delay. */
static void
at86rf230_async_state_delay(void *context)
{
        struct at86rf230_state_change *ctx = context;
        struct at86rf230_local *lp = ctx->lp;
        struct at86rf2xx_chip_data *c = lp->data;
        bool force = false;
        ktime_t tim;

        /* The force state changes are will show as normal states in the
         * state status subregister. We change the to_state to the
         * corresponding one and remember if it was a force change, this
         * differs if we do a state change from STATE_BUSY_RX_AACK.
         */
        switch (ctx->to_state) {
        case STATE_FORCE_TX_ON:
                ctx->to_state = STATE_TX_ON;
                force = true;
                break;
        case STATE_FORCE_TRX_OFF:
                ctx->to_state = STATE_TRX_OFF;
                force = true;
                break;
        default:
                break;
        }

        switch (ctx->from_state) {
        case STATE_TRX_OFF:
                switch (ctx->to_state) {
                case STATE_RX_AACK_ON:
                        tim = c->t_off_to_aack * NSEC_PER_USEC;
                        /* state change from TRX_OFF to RX_AACK_ON to do a
                         * calibration, we need to reset the timeout for the
                         * next one.
                         */
                        lp->cal_timeout = jiffies + AT86RF2XX_CAL_LOOP_TIMEOUT;
                        goto change;
                case STATE_TX_ARET_ON:
                case STATE_TX_ON:
                        tim = c->t_off_to_tx_on * NSEC_PER_USEC;
                        /* state change from TRX_OFF to TX_ON or ARET_ON to do
                         * a calibration, we need to reset the timeout for the
                         * next one.
                         */
                        lp->cal_timeout = jiffies + AT86RF2XX_CAL_LOOP_TIMEOUT;
                        goto change;
                default:
                        break;
                }
                break;
        case STATE_BUSY_RX_AACK:
                switch (ctx->to_state) {
                case STATE_TRX_OFF:
                case STATE_TX_ON:
                        /* Wait for worst case receiving time if we
                         * didn't make a force change from BUSY_RX_AACK
                         * to TX_ON or TRX_OFF.
                         */
                        if (!force) {
                                tim = (c->t_frame + c->t_p_ack) * NSEC_PER_USEC;
                                goto change;
                        }
                        break;
                default:
                        break;
                }
                break;
        /* Default value, means RESET state */
        case STATE_P_ON:
                switch (ctx->to_state) {
                case STATE_TRX_OFF:
                        tim = c->t_reset_to_off * NSEC_PER_USEC;
                        goto change;
                default:
                        break;
                }
                break;
        default:
                break;
        }

        /* Default delay is 1us in the most cases */
        udelay(1);
        at86rf230_async_state_timer(&ctx->timer);
        return;

change:
        hrtimer_start(&ctx->timer, tim, HRTIMER_MODE_REL);
}

static void
at86rf230_async_state_change_start(void *context)
{
        struct at86rf230_state_change *ctx = context;
        struct at86rf230_local *lp = ctx->lp;
        u8 *buf = ctx->buf;
        const u8 trx_state = buf[1] & TRX_STATE_MASK;

        /* Check for "possible" STATE_TRANSITION_IN_PROGRESS */
        if (trx_state == STATE_TRANSITION_IN_PROGRESS) {
                udelay(1);
                at86rf230_async_read_reg(lp, RG_TRX_STATUS, ctx,
                                         at86rf230_async_state_change_start);
                return;
        }

        /* Check if we already are in the state which we change in */
        if (trx_state == ctx->to_state) {
                if (ctx->complete)
                        ctx->complete(context);
                return;
        }

        /* Set current state to the context of state change */
        ctx->from_state = trx_state;

        /* Going into the next step for a state change which do a timing
         * relevant delay.
         */
        at86rf230_async_write_reg(lp, RG_TRX_STATE, ctx->to_state, ctx,
                                  at86rf230_async_state_delay);
}

static void
at86rf230_async_state_change(struct at86rf230_local *lp,
                             struct at86rf230_state_change *ctx,
                             const u8 state, void (*complete)(void *context))
{
        /* Initialization for the state change context */
        ctx->to_state = state;
        ctx->complete = complete;
        at86rf230_async_read_reg(lp, RG_TRX_STATUS, ctx,
                                 at86rf230_async_state_change_start);
}

static void
at86rf230_sync_state_change_complete(void *context)
{
        struct at86rf230_state_change *ctx = context;
        struct at86rf230_local *lp = ctx->lp;

        complete(&lp->state_complete);
}

/* This function do a sync framework above the async state change.
 * Some callbacks of the IEEE 802.15.4 driver interface need to be
 * handled synchronously.
 */
static int
at86rf230_sync_state_change(struct at86rf230_local *lp, unsigned int state)
{
        unsigned long rc;

        at86rf230_async_state_change(lp, &lp->state, state,
                                     at86rf230_sync_state_change_complete);

        rc = wait_for_completion_timeout(&lp->state_complete,
                                         msecs_to_jiffies(100));
        if (!rc) {
                at86rf230_async_error(lp, &lp->state, -ETIMEDOUT);
                return -ETIMEDOUT;
        }

        return 0;
}

static void
at86rf230_tx_complete(void *context)
{
        struct at86rf230_state_change *ctx = context;
        struct at86rf230_local *lp = ctx->lp;

        if (ctx->trac == IEEE802154_SUCCESS)
                ieee802154_xmit_complete(lp->hw, lp->tx_skb, false);
        else
                ieee802154_xmit_error(lp->hw, lp->tx_skb, ctx->trac);

        kfree(ctx);
}

static void
at86rf230_tx_on(void *context)
{
        struct at86rf230_state_change *ctx = context;
        struct at86rf230_local *lp = ctx->lp;

        at86rf230_async_state_change(lp, ctx, STATE_RX_AACK_ON,
                                     at86rf230_tx_complete);
}

static void
at86rf230_tx_trac_check(void *context)
{
        struct at86rf230_state_change *ctx = context;
        struct at86rf230_local *lp = ctx->lp;
        u8 trac = TRAC_MASK(ctx->buf[1]);

        switch (trac) {
        case TRAC_SUCCESS:
        case TRAC_SUCCESS_DATA_PENDING:
                ctx->trac = IEEE802154_SUCCESS;
                break;
        case TRAC_CHANNEL_ACCESS_FAILURE:
                ctx->trac = IEEE802154_CHANNEL_ACCESS_FAILURE;
                break;
        case TRAC_NO_ACK:
                ctx->trac = IEEE802154_NO_ACK;
                break;
        default:
                ctx->trac = IEEE802154_SYSTEM_ERROR;
        }

        at86rf230_async_state_change(lp, ctx, STATE_TX_ON, at86rf230_tx_on);
}

static void
at86rf230_rx_read_frame_complete(void *context)
{
        struct at86rf230_state_change *ctx = context;
        struct at86rf230_local *lp = ctx->lp;
        const u8 *buf = ctx->buf;
        struct sk_buff *skb;
        u8 len, lqi;

        len = buf[1];
        if (!ieee802154_is_valid_psdu_len(len)) {
                dev_vdbg(&lp->spi->dev, "corrupted frame received\n");
                len = IEEE802154_MTU;
        }
        lqi = buf[2 + len];

        skb = dev_alloc_skb(IEEE802154_MTU);
        if (!skb) {
                dev_vdbg(&lp->spi->dev, "failed to allocate sk_buff\n");
                kfree(ctx);
                return;
        }

        skb_put_data(skb, buf + 2, len);
        ieee802154_rx_irqsafe(lp->hw, skb, lqi);
        kfree(ctx);
}

static void
at86rf230_rx_trac_check(void *context)
{
        struct at86rf230_state_change *ctx = context;
        struct at86rf230_local *lp = ctx->lp;
        u8 *buf = ctx->buf;
        int rc;

        buf[0] = CMD_FB;
        ctx->trx.len = AT86RF2XX_MAX_BUF;
        ctx->msg.complete = at86rf230_rx_read_frame_complete;
        rc = spi_async(lp->spi, &ctx->msg);
        if (rc) {
                ctx->trx.len = 2;
                at86rf230_async_error(lp, ctx, rc);
        }
}

static void
at86rf230_irq_trx_end(void *context)
{
        struct at86rf230_state_change *ctx = context;
        struct at86rf230_local *lp = ctx->lp;

        if (lp->is_tx) {
                lp->is_tx = 0;
                at86rf230_async_read_reg(lp, RG_TRX_STATE, ctx,
                                         at86rf230_tx_trac_check);
        } else {
                at86rf230_async_read_reg(lp, RG_TRX_STATE, ctx,
                                         at86rf230_rx_trac_check);
        }
}

static void
at86rf230_irq_status(void *context)
{
        struct at86rf230_state_change *ctx = context;
        struct at86rf230_local *lp = ctx->lp;
        const u8 *buf = ctx->buf;
        u8 irq = buf[1];

        enable_irq(lp->spi->irq);

        if (irq & IRQ_TRX_END) {
                at86rf230_irq_trx_end(ctx);
        } else {
                dev_err(&lp->spi->dev, "not supported irq %02x received\n",
                        irq);
                kfree(ctx);
        }
}

static void
at86rf230_setup_spi_messages(struct at86rf230_local *lp,
                             struct at86rf230_state_change *state)
{
        state->lp = lp;
        state->irq = lp->spi->irq;
        spi_message_init(&state->msg);
        state->msg.context = state;
        state->trx.len = 2;
        state->trx.tx_buf = state->buf;
        state->trx.rx_buf = state->buf;
        spi_message_add_tail(&state->trx, &state->msg);
        hrtimer_setup(&state->timer, at86rf230_async_state_timer, CLOCK_MONOTONIC,
                      HRTIMER_MODE_REL);
}

static irqreturn_t at86rf230_isr(int irq, void *data)
{
        struct at86rf230_local *lp = data;
        struct at86rf230_state_change *ctx;
        int rc;

        disable_irq_nosync(irq);

        ctx = kzalloc_obj(*ctx, GFP_ATOMIC);
        if (!ctx) {
                enable_irq(irq);
                return IRQ_NONE;
        }

        at86rf230_setup_spi_messages(lp, ctx);
        /* tell on error handling to free ctx */
        ctx->free = true;

        ctx->buf[0] = (RG_IRQ_STATUS & CMD_REG_MASK) | CMD_REG;
        ctx->msg.complete = at86rf230_irq_status;
        rc = spi_async(lp->spi, &ctx->msg);
        if (rc) {
                at86rf230_async_error(lp, ctx, rc);
                enable_irq(irq);
                return IRQ_NONE;
        }

        return IRQ_HANDLED;
}

static void
at86rf230_write_frame_complete(void *context)
{
        struct at86rf230_state_change *ctx = context;
        struct at86rf230_local *lp = ctx->lp;

        ctx->trx.len = 2;

        if (lp->slp_tr)
                at86rf230_slp_tr_rising_edge(lp);
        else
                at86rf230_async_write_reg(lp, RG_TRX_STATE, STATE_BUSY_TX, ctx,
                                          NULL);
}

static void
at86rf230_write_frame(void *context)
{
        struct at86rf230_state_change *ctx = context;
        struct at86rf230_local *lp = ctx->lp;
        struct sk_buff *skb = lp->tx_skb;
        u8 *buf = ctx->buf;
        int rc;

        lp->is_tx = 1;

        buf[0] = CMD_FB | CMD_WRITE;
        buf[1] = skb->len + 2;
        memcpy(buf + 2, skb->data, skb->len);
        ctx->trx.len = skb->len + 2;
        ctx->msg.complete = at86rf230_write_frame_complete;
        rc = spi_async(lp->spi, &ctx->msg);
        if (rc) {
                ctx->trx.len = 2;
                at86rf230_async_error(lp, ctx, rc);
        }
}

static void
at86rf230_xmit_tx_on(void *context)
{
        struct at86rf230_state_change *ctx = context;
        struct at86rf230_local *lp = ctx->lp;

        at86rf230_async_state_change(lp, ctx, STATE_TX_ARET_ON,
                                     at86rf230_write_frame);
}

static void
at86rf230_xmit_start(void *context)
{
        struct at86rf230_state_change *ctx = context;
        struct at86rf230_local *lp = ctx->lp;

        /* check if we change from off state */
        if (lp->is_tx_from_off)
                at86rf230_async_state_change(lp, ctx, STATE_TX_ARET_ON,
                                             at86rf230_write_frame);
        else
                at86rf230_async_state_change(lp, ctx, STATE_TX_ON,
                                             at86rf230_xmit_tx_on);
}

static int
at86rf230_xmit(struct ieee802154_hw *hw, struct sk_buff *skb)
{
        struct at86rf230_local *lp = hw->priv;
        struct at86rf230_state_change *ctx = &lp->tx;

        lp->tx_skb = skb;
        lp->tx_retry = 0;

        /* After 5 minutes in PLL and the same frequency we run again the
         * calibration loops which is recommended by at86rf2xx datasheets.
         *
         * The calibration is initiate by a state change from TRX_OFF
         * to TX_ON, the lp->cal_timeout should be reinit by state_delay
         * function then to start in the next 5 minutes.
         */
        if (time_is_before_jiffies(lp->cal_timeout)) {
                lp->is_tx_from_off = true;
                at86rf230_async_state_change(lp, ctx, STATE_TRX_OFF,
                                             at86rf230_xmit_start);
        } else {
                lp->is_tx_from_off = false;
                at86rf230_xmit_start(ctx);
        }

        return 0;
}

static int
at86rf230_ed(struct ieee802154_hw *hw, u8 *level)
{
        WARN_ON(!level);
        *level = 0xbe;
        return 0;
}

static int
at86rf230_start(struct ieee802154_hw *hw)
{
        struct at86rf230_local *lp = hw->priv;

        at86rf230_awake(lp);
        enable_irq(lp->spi->irq);

        return at86rf230_sync_state_change(lp, STATE_RX_AACK_ON);
}

static void
at86rf230_stop(struct ieee802154_hw *hw)
{
        struct at86rf230_local *lp = hw->priv;
        u8 csma_seed[2];

        at86rf230_sync_state_change(lp, STATE_FORCE_TRX_OFF);

        disable_irq(lp->spi->irq);

        /* It's recommended to set random new csma_seeds before sleep state.
         * Makes only sense in the stop callback, not doing this inside of
         * at86rf230_sleep, this is also used when we don't transmit afterwards
         * when calling start callback again.
         */
        get_random_bytes(csma_seed, ARRAY_SIZE(csma_seed));
        at86rf230_write_subreg(lp, SR_CSMA_SEED_0, csma_seed[0]);
        at86rf230_write_subreg(lp, SR_CSMA_SEED_1, csma_seed[1]);

        at86rf230_sleep(lp);
}

static int
at86rf23x_set_channel(struct at86rf230_local *lp, u8 page, u8 channel)
{
        return at86rf230_write_subreg(lp, SR_CHANNEL, channel);
}

#define AT86RF2XX_MAX_ED_LEVELS 0xF
static const s32 at86rf233_ed_levels[AT86RF2XX_MAX_ED_LEVELS + 1] = {
        -9400, -9200, -9000, -8800, -8600, -8400, -8200, -8000, -7800, -7600,
        -7400, -7200, -7000, -6800, -6600, -6400,
};

static const s32 at86rf231_ed_levels[AT86RF2XX_MAX_ED_LEVELS + 1] = {
        -9100, -8900, -8700, -8500, -8300, -8100, -7900, -7700, -7500, -7300,
        -7100, -6900, -6700, -6500, -6300, -6100,
};

static const s32 at86rf212_ed_levels_100[AT86RF2XX_MAX_ED_LEVELS + 1] = {
        -10000, -9800, -9600, -9400, -9200, -9000, -8800, -8600, -8400, -8200,
        -8000, -7800, -7600, -7400, -7200, -7000,
};

static const s32 at86rf212_ed_levels_98[AT86RF2XX_MAX_ED_LEVELS + 1] = {
        -9800, -9600, -9400, -9200, -9000, -8800, -8600, -8400, -8200, -8000,
        -7800, -7600, -7400, -7200, -7000, -6800,
};

static inline int
at86rf212_update_cca_ed_level(struct at86rf230_local *lp, int rssi_base_val)
{
        unsigned int cca_ed_thres;
        int rc;

        rc = at86rf230_read_subreg(lp, SR_CCA_ED_THRES, &cca_ed_thres);
        if (rc < 0)
                return rc;

        switch (rssi_base_val) {
        case -98:
                lp->hw->phy->supported.cca_ed_levels = at86rf212_ed_levels_98;
                lp->hw->phy->supported.cca_ed_levels_size = ARRAY_SIZE(at86rf212_ed_levels_98);
                lp->hw->phy->cca_ed_level = at86rf212_ed_levels_98[cca_ed_thres];
                break;
        case -100:
                lp->hw->phy->supported.cca_ed_levels = at86rf212_ed_levels_100;
                lp->hw->phy->supported.cca_ed_levels_size = ARRAY_SIZE(at86rf212_ed_levels_100);
                lp->hw->phy->cca_ed_level = at86rf212_ed_levels_100[cca_ed_thres];
                break;
        default:
                WARN_ON(1);
        }

        return 0;
}

static int
at86rf212_set_channel(struct at86rf230_local *lp, u8 page, u8 channel)
{
        int rc;

        if (channel == 0)
                rc = at86rf230_write_subreg(lp, SR_SUB_MODE, 0);
        else
                rc = at86rf230_write_subreg(lp, SR_SUB_MODE, 1);
        if (rc < 0)
                return rc;

        if (page == 0) {
                rc = at86rf230_write_subreg(lp, SR_BPSK_QPSK, 0);
                lp->data->rssi_base_val = -100;
        } else {
                rc = at86rf230_write_subreg(lp, SR_BPSK_QPSK, 1);
                lp->data->rssi_base_val = -98;
        }
        if (rc < 0)
                return rc;

        rc = at86rf212_update_cca_ed_level(lp, lp->data->rssi_base_val);
        if (rc < 0)
                return rc;

        return at86rf230_write_subreg(lp, SR_CHANNEL, channel);
}

static int
at86rf230_channel(struct ieee802154_hw *hw, u8 page, u8 channel)
{
        struct at86rf230_local *lp = hw->priv;
        int rc;

        rc = lp->data->set_channel(lp, page, channel);
        /* Wait for PLL */
        usleep_range(lp->data->t_channel_switch,
                     lp->data->t_channel_switch + 10);

        lp->cal_timeout = jiffies + AT86RF2XX_CAL_LOOP_TIMEOUT;
        return rc;
}

static int
at86rf230_set_hw_addr_filt(struct ieee802154_hw *hw,
                           struct ieee802154_hw_addr_filt *filt,
                           unsigned long changed)
{
        struct at86rf230_local *lp = hw->priv;

        if (changed & IEEE802154_AFILT_SADDR_CHANGED) {
                u16 addr = le16_to_cpu(filt->short_addr);

                dev_vdbg(&lp->spi->dev, "%s called for saddr\n", __func__);
                __at86rf230_write(lp, RG_SHORT_ADDR_0, addr);
                __at86rf230_write(lp, RG_SHORT_ADDR_1, addr >> 8);
        }

        if (changed & IEEE802154_AFILT_PANID_CHANGED) {
                u16 pan = le16_to_cpu(filt->pan_id);

                dev_vdbg(&lp->spi->dev, "%s called for pan id\n", __func__);
                __at86rf230_write(lp, RG_PAN_ID_0, pan);
                __at86rf230_write(lp, RG_PAN_ID_1, pan >> 8);
        }

        if (changed & IEEE802154_AFILT_IEEEADDR_CHANGED) {
                u8 i, addr[8];

                memcpy(addr, &filt->ieee_addr, 8);
                dev_vdbg(&lp->spi->dev, "%s called for IEEE addr\n", __func__);
                for (i = 0; i < 8; i++)
                        __at86rf230_write(lp, RG_IEEE_ADDR_0 + i, addr[i]);
        }

        if (changed & IEEE802154_AFILT_PANC_CHANGED) {
                dev_vdbg(&lp->spi->dev, "%s called for panc change\n", __func__);
                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;
}

#define AT86RF23X_MAX_TX_POWERS 0xF
static const s32 at86rf233_powers[AT86RF23X_MAX_TX_POWERS + 1] = {
        400, 370, 340, 300, 250, 200, 100, 0, -100, -200, -300, -400, -600,
        -800, -1200, -1700,
};

static const s32 at86rf231_powers[AT86RF23X_MAX_TX_POWERS + 1] = {
        300, 280, 230, 180, 130, 70, 0, -100, -200, -300, -400, -500, -700,
        -900, -1200, -1700,
};

#define AT86RF212_MAX_TX_POWERS 0x1F
static const s32 at86rf212_powers[AT86RF212_MAX_TX_POWERS + 1] = {
        500, 400, 300, 200, 100, 0, -100, -200, -300, -400, -500, -600, -700,
        -800, -900, -1000, -1100, -1200, -1300, -1400, -1500, -1600, -1700,
        -1800, -1900, -2000, -2100, -2200, -2300, -2400, -2500, -2600,
};

static int
at86rf23x_set_txpower(struct at86rf230_local *lp, s32 mbm)
{
        u32 i;

        for (i = 0; i < lp->hw->phy->supported.tx_powers_size; i++) {
                if (lp->hw->phy->supported.tx_powers[i] == mbm)
                        return at86rf230_write_subreg(lp, SR_TX_PWR_23X, i);
        }

        return -EINVAL;
}

static int
at86rf212_set_txpower(struct at86rf230_local *lp, s32 mbm)
{
        u32 i;

        for (i = 0; i < lp->hw->phy->supported.tx_powers_size; i++) {
                if (lp->hw->phy->supported.tx_powers[i] == mbm)
                        return at86rf230_write_subreg(lp, SR_TX_PWR_212, i);
        }

        return -EINVAL;
}

static int
at86rf230_set_txpower(struct ieee802154_hw *hw, s32 mbm)
{
        struct at86rf230_local *lp = hw->priv;

        return lp->data->set_txpower(lp, mbm);
}

static int
at86rf230_set_lbt(struct ieee802154_hw *hw, bool on)
{
        struct at86rf230_local *lp = hw->priv;

        return at86rf230_write_subreg(lp, SR_CSMA_LBT_MODE, on);
}

static int
at86rf230_set_cca_mode(struct ieee802154_hw *hw,
                       const struct wpan_phy_cca *cca)
{
        struct at86rf230_local *lp = hw->priv;
        u8 val;

        /* mapping 802.15.4 to driver spec */
        switch (cca->mode) {
        case NL802154_CCA_ENERGY:
                val = 1;
                break;
        case NL802154_CCA_CARRIER:
                val = 2;
                break;
        case NL802154_CCA_ENERGY_CARRIER:
                switch (cca->opt) {
                case NL802154_CCA_OPT_ENERGY_CARRIER_AND:
                        val = 3;
                        break;
                case NL802154_CCA_OPT_ENERGY_CARRIER_OR:
                        val = 0;
                        break;
                default:
                        return -EINVAL;
                }
                break;
        default:
                return -EINVAL;
        }

        return at86rf230_write_subreg(lp, SR_CCA_MODE, val);
}

static int
at86rf230_set_cca_ed_level(struct ieee802154_hw *hw, s32 mbm)
{
        struct at86rf230_local *lp = hw->priv;
        u32 i;

        for (i = 0; i < hw->phy->supported.cca_ed_levels_size; i++) {
                if (hw->phy->supported.cca_ed_levels[i] == mbm)
                        return at86rf230_write_subreg(lp, SR_CCA_ED_THRES, i);
        }

        return -EINVAL;
}

static int
at86rf230_set_csma_params(struct ieee802154_hw *hw, u8 min_be, u8 max_be,
                          u8 retries)
{
        struct at86rf230_local *lp = hw->priv;
        int rc;

        rc = at86rf230_write_subreg(lp, SR_MIN_BE, min_be);
        if (rc)
                return rc;

        rc = at86rf230_write_subreg(lp, SR_MAX_BE, max_be);
        if (rc)
                return rc;

        return at86rf230_write_subreg(lp, SR_MAX_CSMA_RETRIES, retries);
}

static int
at86rf230_set_frame_retries(struct ieee802154_hw *hw, s8 retries)
{
        struct at86rf230_local *lp = hw->priv;

        return at86rf230_write_subreg(lp, SR_MAX_FRAME_RETRIES, retries);
}

static int
at86rf230_set_promiscuous_mode(struct ieee802154_hw *hw, const bool on)
{
        struct at86rf230_local *lp = hw->priv;
        int rc;

        if (on) {
                rc = at86rf230_write_subreg(lp, SR_AACK_DIS_ACK, 1);
                if (rc < 0)
                        return rc;

                rc = at86rf230_write_subreg(lp, SR_AACK_PROM_MODE, 1);
                if (rc < 0)
                        return rc;
        } else {
                rc = at86rf230_write_subreg(lp, SR_AACK_PROM_MODE, 0);
                if (rc < 0)
                        return rc;

                rc = at86rf230_write_subreg(lp, SR_AACK_DIS_ACK, 0);
                if (rc < 0)
                        return rc;
        }

        return 0;
}

static const struct ieee802154_ops at86rf230_ops = {
        .owner = THIS_MODULE,
        .xmit_async = at86rf230_xmit,
        .ed = at86rf230_ed,
        .set_channel = at86rf230_channel,
        .start = at86rf230_start,
        .stop = at86rf230_stop,
        .set_hw_addr_filt = at86rf230_set_hw_addr_filt,
        .set_txpower = at86rf230_set_txpower,
        .set_lbt = at86rf230_set_lbt,
        .set_cca_mode = at86rf230_set_cca_mode,
        .set_cca_ed_level = at86rf230_set_cca_ed_level,
        .set_csma_params = at86rf230_set_csma_params,
        .set_frame_retries = at86rf230_set_frame_retries,
        .set_promiscuous_mode = at86rf230_set_promiscuous_mode,
};

static struct at86rf2xx_chip_data at86rf233_data = {
        .t_sleep_cycle = 330,
        .t_channel_switch = 11,
        .t_reset_to_off = 26,
        .t_off_to_aack = 80,
        .t_off_to_tx_on = 80,
        .t_off_to_sleep = 35,
        .t_sleep_to_off = 1000,
        .t_frame = 4096,
        .t_p_ack = 545,
        .rssi_base_val = -94,
        .set_channel = at86rf23x_set_channel,
        .set_txpower = at86rf23x_set_txpower,
};

static struct at86rf2xx_chip_data at86rf231_data = {
        .t_sleep_cycle = 330,
        .t_channel_switch = 24,
        .t_reset_to_off = 37,
        .t_off_to_aack = 110,
        .t_off_to_tx_on = 110,
        .t_off_to_sleep = 35,
        .t_sleep_to_off = 1000,
        .t_frame = 4096,
        .t_p_ack = 545,
        .rssi_base_val = -91,
        .set_channel = at86rf23x_set_channel,
        .set_txpower = at86rf23x_set_txpower,
};

static struct at86rf2xx_chip_data at86rf212_data = {
        .t_sleep_cycle = 330,
        .t_channel_switch = 11,
        .t_reset_to_off = 26,
        .t_off_to_aack = 200,
        .t_off_to_tx_on = 200,
        .t_off_to_sleep = 35,
        .t_sleep_to_off = 1000,
        .t_frame = 4096,
        .t_p_ack = 545,
        .rssi_base_val = -100,
        .set_channel = at86rf212_set_channel,
        .set_txpower = at86rf212_set_txpower,
};

static int at86rf230_hw_init(struct at86rf230_local *lp, u8 xtal_trim)
{
        int rc, irq_type, irq_pol = IRQ_ACTIVE_HIGH;
        unsigned int dvdd;
        u8 csma_seed[2];

        rc = at86rf230_sync_state_change(lp, STATE_FORCE_TRX_OFF);
        if (rc)
                return rc;

        irq_type = irq_get_trigger_type(lp->spi->irq);
        if (irq_type == IRQ_TYPE_EDGE_FALLING ||
            irq_type == IRQ_TYPE_LEVEL_LOW)
                irq_pol = IRQ_ACTIVE_LOW;

        rc = at86rf230_write_subreg(lp, SR_IRQ_POLARITY, irq_pol);
        if (rc)
                return rc;

        rc = at86rf230_write_subreg(lp, SR_RX_SAFE_MODE, 1);
        if (rc)
                return rc;

        rc = at86rf230_write_subreg(lp, SR_IRQ_MASK, IRQ_TRX_END);
        if (rc)
                return rc;

        /* reset values differs in at86rf231 and at86rf233 */
        rc = at86rf230_write_subreg(lp, SR_IRQ_MASK_MODE, 0);
        if (rc)
                return rc;

        get_random_bytes(csma_seed, ARRAY_SIZE(csma_seed));
        rc = at86rf230_write_subreg(lp, SR_CSMA_SEED_0, csma_seed[0]);
        if (rc)
                return rc;
        rc = at86rf230_write_subreg(lp, SR_CSMA_SEED_1, csma_seed[1]);
        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 */
        usleep_range(lp->data->t_sleep_cycle,
                     lp->data->t_sleep_cycle + 100);

        /* xtal_trim value is calculated by:
         * CL = 0.5 * (CX + CTRIM + CPAR)
         *
         * whereas:
         * CL = capacitor of used crystal
         * CX = connected capacitors at xtal pins
         * CPAR = in all at86rf2xx datasheets this is a constant value 3 pF,
         *        but this is different on each board setup. You need to fine
         *        tuning this value via CTRIM.
         * CTRIM = variable capacitor setting. Resolution is 0.3 pF range is
         *         0 pF upto 4.5 pF.
         *
         * Examples:
         * atben transceiver:
         *
         * CL = 8 pF
         * CX = 12 pF
         * CPAR = 3 pF (We assume the magic constant from datasheet)
         * CTRIM = 0.9 pF
         *
         * (12+0.9+3)/2 = 7.95 which is nearly at 8 pF
         *
         * xtal_trim = 0x3
         *
         * openlabs transceiver:
         *
         * CL = 16 pF
         * CX = 22 pF
         * CPAR = 3 pF (We assume the magic constant from datasheet)
         * CTRIM = 4.5 pF
         *
         * (22+4.5+3)/2 = 14.75 which is the nearest value to 16 pF
         *
         * xtal_trim = 0xf
         */
        rc = at86rf230_write_subreg(lp, SR_XTAL_TRIM, xtal_trim);
        if (rc)
                return rc;

        rc = at86rf230_read_subreg(lp, SR_DVDD_OK, &dvdd);
        if (rc)
                return rc;
        if (!dvdd) {
                dev_err(&lp->spi->dev, "DVDD error\n");
                return -EINVAL;
        }

        /* Force setting slotted operation bit to 0. Sometimes the atben
         * sets this bit and I don't know why. We set this always force
         * to zero while probing.
         */
        return at86rf230_write_subreg(lp, SR_SLOTTED_OPERATION, 0);
}

static int
at86rf230_detect_device(struct at86rf230_local *lp)
{
        unsigned int part, version, val;
        u16 man_id = 0;
        const char *chip;
        int rc;

        rc = __at86rf230_read(lp, RG_MAN_ID_0, &val);
        if (rc)
                return rc;
        man_id |= val;

        rc = __at86rf230_read(lp, RG_MAN_ID_1, &val);
        if (rc)
                return rc;
        man_id |= (val << 8);

        rc = __at86rf230_read(lp, RG_PART_NUM, &part);
        if (rc)
                return rc;

        rc = __at86rf230_read(lp, RG_VERSION_NUM, &version);
        if (rc)
                return rc;

        if (man_id != 0x001f) {
                dev_err(&lp->spi->dev, "Non-Atmel dev found (MAN_ID %02x %02x)\n",
                        man_id >> 8, man_id & 0xFF);
                return -EINVAL;
        }

        lp->hw->flags = IEEE802154_HW_TX_OMIT_CKSUM |
                        IEEE802154_HW_CSMA_PARAMS |
                        IEEE802154_HW_FRAME_RETRIES | IEEE802154_HW_AFILT |
                        IEEE802154_HW_PROMISCUOUS;

        lp->hw->phy->flags = WPAN_PHY_FLAG_TXPOWER |
                             WPAN_PHY_FLAG_CCA_ED_LEVEL |
                             WPAN_PHY_FLAG_CCA_MODE;

        lp->hw->phy->supported.cca_modes = BIT(NL802154_CCA_ENERGY) |
                BIT(NL802154_CCA_CARRIER) | BIT(NL802154_CCA_ENERGY_CARRIER);
        lp->hw->phy->supported.cca_opts = BIT(NL802154_CCA_OPT_ENERGY_CARRIER_AND) |
                BIT(NL802154_CCA_OPT_ENERGY_CARRIER_OR);

        lp->hw->phy->cca.mode = NL802154_CCA_ENERGY;

        switch (part) {
        case 2:
                chip = "at86rf230";
                rc = -ENOTSUPP;
                goto not_supp;
        case 3:
                chip = "at86rf231";
                lp->data = &at86rf231_data;
                lp->hw->phy->supported.channels[0] = 0x7FFF800;
                lp->hw->phy->current_channel = 11;
                lp->hw->phy->supported.tx_powers = at86rf231_powers;
                lp->hw->phy->supported.tx_powers_size = ARRAY_SIZE(at86rf231_powers);
                lp->hw->phy->supported.cca_ed_levels = at86rf231_ed_levels;
                lp->hw->phy->supported.cca_ed_levels_size = ARRAY_SIZE(at86rf231_ed_levels);
                break;
        case 7:
                chip = "at86rf212";
                lp->data = &at86rf212_data;
                lp->hw->flags |= IEEE802154_HW_LBT;
                lp->hw->phy->supported.channels[0] = 0x00007FF;
                lp->hw->phy->supported.channels[2] = 0x00007FF;
                lp->hw->phy->current_channel = 5;
                lp->hw->phy->supported.lbt = NL802154_SUPPORTED_BOOL_BOTH;
                lp->hw->phy->supported.tx_powers = at86rf212_powers;
                lp->hw->phy->supported.tx_powers_size = ARRAY_SIZE(at86rf212_powers);
                lp->hw->phy->supported.cca_ed_levels = at86rf212_ed_levels_100;
                lp->hw->phy->supported.cca_ed_levels_size = ARRAY_SIZE(at86rf212_ed_levels_100);
                break;
        case 11:
                chip = "at86rf233";
                lp->data = &at86rf233_data;
                lp->hw->phy->supported.channels[0] = 0x7FFF800;
                lp->hw->phy->current_channel = 13;
                lp->hw->phy->supported.tx_powers = at86rf233_powers;
                lp->hw->phy->supported.tx_powers_size = ARRAY_SIZE(at86rf233_powers);
                lp->hw->phy->supported.cca_ed_levels = at86rf233_ed_levels;
                lp->hw->phy->supported.cca_ed_levels_size = ARRAY_SIZE(at86rf233_ed_levels);
                break;
        default:
                chip = "unknown";
                rc = -ENOTSUPP;
                goto not_supp;
        }

        lp->hw->phy->cca_ed_level = lp->hw->phy->supported.cca_ed_levels[7];
        lp->hw->phy->transmit_power = lp->hw->phy->supported.tx_powers[0];

not_supp:
        dev_info(&lp->spi->dev, "Detected %s chip version %d\n", chip, version);

        return rc;
}

static int at86rf230_probe(struct spi_device *spi)
{
        struct ieee802154_hw *hw;
        struct at86rf230_local *lp;
        struct gpio_desc *slp_tr;
        struct gpio_desc *rstn;
        unsigned int status;
        int rc, irq_type;
        u8 xtal_trim;

        if (!spi->irq) {
                dev_err(&spi->dev, "no IRQ specified\n");
                return -EINVAL;
        }

        rc = device_property_read_u8(&spi->dev, "xtal-trim", &xtal_trim);
        if (rc < 0) {
                if (rc != -EINVAL) {
                        dev_err(&spi->dev,
                                "failed to parse xtal-trim: %d\n", rc);
                        return rc;
                }
                xtal_trim = 0;
        }

        rstn = devm_gpiod_get_optional(&spi->dev, "reset", GPIOD_OUT_LOW);
        rc = PTR_ERR_OR_ZERO(rstn);
        if (rc)
                return rc;

        gpiod_set_consumer_name(rstn, "rstn");

        slp_tr = devm_gpiod_get_optional(&spi->dev, "sleep", GPIOD_OUT_LOW);
        rc = PTR_ERR_OR_ZERO(slp_tr);
        if (rc)
                return rc;

        gpiod_set_consumer_name(slp_tr, "slp_tr");

        /* Reset */
        if (rstn) {
                udelay(1);
                gpiod_set_value_cansleep(rstn, 1);
                udelay(1);
                gpiod_set_value_cansleep(rstn, 0);
                usleep_range(120, 240);
        }

        hw = ieee802154_alloc_hw(sizeof(*lp), &at86rf230_ops);
        if (!hw)
                return -ENOMEM;

        lp = hw->priv;
        lp->hw = hw;
        lp->spi = spi;
        lp->slp_tr = slp_tr;
        hw->parent = &spi->dev;
        ieee802154_random_extended_addr(&hw->phy->perm_extended_addr);

        lp->regmap = devm_regmap_init_spi(spi, &at86rf230_regmap_spi_config);
        if (IS_ERR(lp->regmap)) {
                rc = PTR_ERR(lp->regmap);
                dev_err(&spi->dev, "Failed to allocate register map: %d\n",
                        rc);
                goto free_dev;
        }

        at86rf230_setup_spi_messages(lp, &lp->state);
        at86rf230_setup_spi_messages(lp, &lp->tx);

        rc = at86rf230_detect_device(lp);
        if (rc < 0)
                goto free_dev;

        init_completion(&lp->state_complete);

        spi_set_drvdata(spi, lp);

        rc = at86rf230_hw_init(lp, xtal_trim);
        if (rc)
                goto free_dev;

        /* Read irq status register to reset irq line */
        rc = at86rf230_read_subreg(lp, RG_IRQ_STATUS, 0xff, 0, &status);
        if (rc)
                goto free_dev;

        irq_type = irq_get_trigger_type(spi->irq);
        if (!irq_type)
                irq_type = IRQF_TRIGGER_HIGH;

        rc = devm_request_irq(&spi->dev, spi->irq, at86rf230_isr,
                              IRQF_SHARED | irq_type, dev_name(&spi->dev), lp);
        if (rc)
                goto free_dev;

        /* disable_irq by default and wait for starting hardware */
        disable_irq(spi->irq);

        /* going into sleep by default */
        at86rf230_sleep(lp);

        rc = ieee802154_register_hw(lp->hw);
        if (rc)
                goto free_dev;

        return rc;

free_dev:
        ieee802154_free_hw(lp->hw);

        return rc;
}

static void at86rf230_remove(struct spi_device *spi)
{
        struct at86rf230_local *lp = spi_get_drvdata(spi);

        /* mask all at86rf230 irq's */
        at86rf230_write_subreg(lp, SR_IRQ_MASK, 0);
        ieee802154_unregister_hw(lp->hw);
        ieee802154_free_hw(lp->hw);
        dev_dbg(&spi->dev, "unregistered at86rf230\n");
}

static const struct of_device_id at86rf230_of_match[] = {
        { .compatible = "atmel,at86rf230", },
        { .compatible = "atmel,at86rf231", },
        { .compatible = "atmel,at86rf233", },
        { .compatible = "atmel,at86rf212", },
        { },
};
MODULE_DEVICE_TABLE(of, at86rf230_of_match);

static const struct spi_device_id at86rf230_device_id[] = {
        { .name = "at86rf230", },
        { .name = "at86rf231", },
        { .name = "at86rf233", },
        { .name = "at86rf212", },
        { },
};
MODULE_DEVICE_TABLE(spi, at86rf230_device_id);

static struct spi_driver at86rf230_driver = {
        .id_table = at86rf230_device_id,
        .driver = {
                .of_match_table = at86rf230_of_match,
                .name   = "at86rf230",
        },
        .probe      = at86rf230_probe,
        .remove     = at86rf230_remove,
};

module_spi_driver(at86rf230_driver);

MODULE_DESCRIPTION("AT86RF230 Transceiver Driver");
MODULE_LICENSE("GPL v2");