at86rf230.c

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/*
 * 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 <[email protected]>
 * Alexander Smirnov <[email protected]>
 */
#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_disabled;
    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 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_BUSY_RX_AACK_ON   0x16
#define STATE_BUSY_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\n", buf[0]);
    dev_vdbg(&lp->spi->dev, "buf[1] = %02x\n", 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\n", status);
    if (msg.status)
        status = msg.status;

    dev_vdbg(&lp->spi->dev, "status = %d\n", status);
    dev_vdbg(&lp->spi->dev, "buf[0] = %02x\n", buf[0]);
    dev_vdbg(&lp->spi->dev, "buf[1] = %02x\n", 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\n", 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\n", status);
    if (msg.status)
        status = msg.status;

    dev_vdbg(&lp->spi->dev, "status = %d\n", status);
    dev_vdbg(&lp->spi->dev, "buf[0] = %02x\n", buf[0]);
    dev_vdbg(&lp->spi->dev, "buf[1] = %02x\n", 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\n", buf[0]);
    dev_vdbg(&lp->spi->dev, "buf[1] = %02x\n", 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\n", status);
    if (msg.status)
        status = msg.status;

    dev_vdbg(&lp->spi->dev, "status = %d\n", status);
    dev_vdbg(&lp->spi->dev, "buf[0] = %02x\n", buf[0]);
    dev_vdbg(&lp->spi->dev, "buf[1] = %02x\n", 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\n", 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\n", status);
    dev_vdbg(&lp->spi->dev, "buf[0] = %02x\n", buf[0]);
    dev_vdbg(&lp->spi->dev, "buf[1] = %02x\n", 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\n", val, state);
    return -EBUSY;

err:
    pr_err("error: %d\n", 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(&lp->lock);
    if  (lp->irq_disabled) {
        spin_unlock(&lp->lock);
        return -EBUSY;
    }
    spin_unlock(&lp->lock);

    might_sleep();

    rc = at86rf230_state(dev, STATE_FORCE_TX_ON);
    if (rc)
        goto err;

    spin_lock_irqsave(&lp->lock, flags);
    lp->is_tx = 1;
    INIT_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\n", 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\n", len, lqi);

    return 0;
err:
    pr_debug("received frame is too small\n");

    kfree_skb(skb);
    return -EINVAL;
}

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,
};

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_disabled = 0;
    spin_unlock_irqrestore(&lp->lock, flags);

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

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

    disable_irq_nosync(irq);

    spin_lock(&lp->lock);
    lp->irq_disabled = 1;
    spin_unlock(&lp->lock);

    schedule_work(&lp->irqwork);

    return IRQ_HANDLED;
}


static int at86rf230_hw_init(struct at86rf230_local *lp)
{
    u8 status;
    int rc;

    rc = at86rf230_read_subreg(lp, SR_TRX_STATUS, &status);
    if (rc)
        return rc;

    dev_info(&lp->spi->dev, "Status: %02x\n", 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\n", status);
    }

    rc = at86rf230_write_subreg(lp, SR_IRQ_MASK, 0xff); /* IRQ_TRX_UR |
                                 * IRQ_CCA_ED |
                                 * IRQ_TRX_END |
                                 * IRQ_PLL_UNL |
                                 * IRQ_PLL_LOCK
                                 */
    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\n", status);

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

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

    return 0;
}

static int at86rf230_suspend(struct spi_device *spi, pm_message_t message)
{
    return 0;
}

static int at86rf230_resume(struct spi_device *spi)
{
    return 0;
}

static int at86rf230_fill_data(struct spi_device *spi)
{
    struct at86rf230_local *lp = spi_get_drvdata(spi);
    struct at86rf230_platform_data *pdata = spi->dev.platform_data;

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

    lp->rstn = pdata->rstn;
    lp->slp_tr = pdata->slp_tr;
    lp->dig2 = pdata->dig2;

    return 0;
}

static int __devinit at86rf230_probe(struct spi_device *spi)
{
    struct ieee802154_dev *dev;
    struct at86rf230_local *lp;
    u8 man_id_0, man_id_1;
    int rc;
    const char *chip;
    int supported = 0;

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

    dev = ieee802154_alloc_device(sizeof(*lp), &at86rf230_ops);
    if (!dev)
        return -ENOMEM;

    lp = dev->priv;
    lp->dev = dev;

    lp->spi = spi;

    dev->priv = lp;
    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;

    mutex_init(&lp->bmux);
    INIT_WORK(&lp->irqwork, at86rf230_irqwork);
    spin_lock_init(&lp->lock);
    init_completion(&lp->tx_complete);

    spi_set_drvdata(spi, lp);

    rc = at86rf230_fill_data(spi);
    if (rc)
        goto err_fill;

    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)\n",
            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\n", 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, at86rf230_isr, IRQF_SHARED,
             dev_name(&spi->dev), lp);
    if (rc)
        goto err_gpio_dir;

    rc = ieee802154_register_device(lp->dev);
    if (rc)
        goto err_irq;

    return rc;

    ieee802154_unregister_device(lp->dev);
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:
err_fill:
    spi_set_drvdata(spi, NULL);
    mutex_destroy(&lp->bmux);
    ieee802154_free_device(lp->dev);
    return rc;
}

static int __devexit 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);

    spi_set_drvdata(spi, NULL);
    mutex_destroy(&lp->bmux);
    ieee802154_free_device(lp->dev);

    dev_dbg(&spi->dev, "unregistered at86rf230\n");
    return 0;
}

static struct spi_driver at86rf230_driver = {
    .driver = {
        .name   = "at86rf230",
        .owner  = THIS_MODULE,
    },
    .probe      = at86rf230_probe,
    .remove     = __devexit_p(at86rf230_remove),
    .suspend    = at86rf230_suspend,
    .resume     = at86rf230_resume,
};

module_spi_driver(at86rf230_driver);

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