radio-si470x-usb.c

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/*
 *  drivers/media/radio/si470x/radio-si470x-usb.c
 *
 *  USB driver for radios with Silicon Labs Si470x FM Radio Receivers
 *
 *  Copyright (c) 2009 Tobias Lorenz <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */


/*
 * ToDo:
 * - add firmware download/update support
 */


/* driver definitions */
#define DRIVER_AUTHOR "Tobias Lorenz <[email protected]>"
#define DRIVER_CARD "Silicon Labs Si470x FM Radio Receiver"
#define DRIVER_DESC "USB radio driver for Si470x FM Radio Receivers"
#define DRIVER_VERSION "1.0.10"

/* kernel includes */
#include <linux/usb.h>
#include <linux/hid.h>
#include <linux/slab.h>

#include "radio-si470x.h"


/* USB Device ID List */
static struct usb_device_id si470x_usb_driver_id_table[] = {
    /* Silicon Labs USB FM Radio Reference Design */
    { USB_DEVICE_AND_INTERFACE_INFO(0x10c4, 0x818a, USB_CLASS_HID, 0, 0) },
    /* ADS/Tech FM Radio Receiver (formerly Instant FM Music) */
    { USB_DEVICE_AND_INTERFACE_INFO(0x06e1, 0xa155, USB_CLASS_HID, 0, 0) },
    /* KWorld USB FM Radio SnapMusic Mobile 700 (FM700) */
    { USB_DEVICE_AND_INTERFACE_INFO(0x1b80, 0xd700, USB_CLASS_HID, 0, 0) },
    /* Sanei Electric, Inc. FM USB Radio (sold as DealExtreme.com PCear) */
    { USB_DEVICE_AND_INTERFACE_INFO(0x10c5, 0x819a, USB_CLASS_HID, 0, 0) },
    /* Axentia ALERT FM USB Receiver */
    { USB_DEVICE_AND_INTERFACE_INFO(0x12cf, 0x7111, USB_CLASS_HID, 0, 0) },
    /* Terminating entry */
    { }
};
MODULE_DEVICE_TABLE(usb, si470x_usb_driver_id_table);



/**************************************************************************
 * Module Parameters
 **************************************************************************/

/* Radio Nr */
static int radio_nr = -1;
module_param(radio_nr, int, 0444);
MODULE_PARM_DESC(radio_nr, "Radio Nr");

/* USB timeout */
static unsigned int usb_timeout = 500;
module_param(usb_timeout, uint, 0644);
MODULE_PARM_DESC(usb_timeout, "USB timeout (ms): *500*");

/* RDS buffer blocks */
static unsigned int rds_buf = 100;
module_param(rds_buf, uint, 0444);
MODULE_PARM_DESC(rds_buf, "RDS buffer entries: *100*");

/* RDS maximum block errors */
static unsigned short max_rds_errors = 1;
/* 0 means   0  errors requiring correction */
/* 1 means 1-2  errors requiring correction (used by original USBRadio.exe) */
/* 2 means 3-5  errors requiring correction */
/* 3 means   6+ errors or errors in checkword, correction not possible */
module_param(max_rds_errors, ushort, 0644);
MODULE_PARM_DESC(max_rds_errors, "RDS maximum block errors: *1*");



/**************************************************************************
 * USB HID Reports
 **************************************************************************/

/* Reports 1-16 give direct read/write access to the 16 Si470x registers */
/* with the (REPORT_ID - 1) corresponding to the register address across USB */
/* endpoint 0 using GET_REPORT and SET_REPORT */
#define REGISTER_REPORT_SIZE    (RADIO_REGISTER_SIZE + 1)
#define REGISTER_REPORT(reg)    ((reg) + 1)

/* Report 17 gives direct read/write access to the entire Si470x register */
/* map across endpoint 0 using GET_REPORT and SET_REPORT */
#define ENTIRE_REPORT_SIZE  (RADIO_REGISTER_NUM * RADIO_REGISTER_SIZE + 1)
#define ENTIRE_REPORT       17

/* Report 18 is used to send the lowest 6 Si470x registers up the HID */
/* interrupt endpoint 1 to Windows every 20 milliseconds for status */
#define RDS_REPORT_SIZE     (RDS_REGISTER_NUM * RADIO_REGISTER_SIZE + 1)
#define RDS_REPORT      18

/* Report 19: LED state */
#define LED_REPORT_SIZE     3
#define LED_REPORT      19

/* Report 19: stream */
#define STREAM_REPORT_SIZE  3
#define STREAM_REPORT       19

/* Report 20: scratch */
#define SCRATCH_PAGE_SIZE   63
#define SCRATCH_REPORT_SIZE (SCRATCH_PAGE_SIZE + 1)
#define SCRATCH_REPORT      20

/* Reports 19-22: flash upgrade of the C8051F321 */
#define WRITE_REPORT_SIZE   4
#define WRITE_REPORT        19
#define FLASH_REPORT_SIZE   64
#define FLASH_REPORT        20
#define CRC_REPORT_SIZE     3
#define CRC_REPORT      21
#define RESPONSE_REPORT_SIZE    2
#define RESPONSE_REPORT     22

/* Report 23: currently unused, but can accept 60 byte reports on the HID */
/* interrupt out endpoint 2 every 1 millisecond */
#define UNUSED_REPORT       23



/**************************************************************************
 * Software/Hardware Versions from Scratch Page
 **************************************************************************/
#define RADIO_SW_VERSION_NOT_BOOTLOADABLE   6
#define RADIO_SW_VERSION            1
#define RADIO_HW_VERSION            1



/**************************************************************************
 * LED State Definitions
 **************************************************************************/
#define LED_COMMAND     0x35

#define NO_CHANGE_LED       0x00
#define ALL_COLOR_LED       0x01    /* streaming state */
#define BLINK_GREEN_LED     0x02    /* connect state */
#define BLINK_RED_LED       0x04
#define BLINK_ORANGE_LED    0x10    /* disconnect state */
#define SOLID_GREEN_LED     0x20    /* tuning/seeking state */
#define SOLID_RED_LED       0x40    /* bootload state */
#define SOLID_ORANGE_LED    0x80



/**************************************************************************
 * Stream State Definitions
 **************************************************************************/
#define STREAM_COMMAND  0x36
#define STREAM_VIDPID   0x00
#define STREAM_AUDIO    0xff



/**************************************************************************
 * Bootloader / Flash Commands
 **************************************************************************/

/* unique id sent to bootloader and required to put into a bootload state */
#define UNIQUE_BL_ID        0x34

/* mask for the flash data */
#define FLASH_DATA_MASK     0x55

/* bootloader commands */
#define GET_SW_VERSION_COMMAND  0x00
#define SET_PAGE_COMMAND    0x01
#define ERASE_PAGE_COMMAND  0x02
#define WRITE_PAGE_COMMAND  0x03
#define CRC_ON_PAGE_COMMAND 0x04
#define READ_FLASH_BYTE_COMMAND 0x05
#define RESET_DEVICE_COMMAND    0x06
#define GET_HW_VERSION_COMMAND  0x07
#define BLANK           0xff

/* bootloader command responses */
#define COMMAND_OK      0x01
#define COMMAND_FAILED      0x02
#define COMMAND_PENDING     0x03



/**************************************************************************
 * General Driver Functions - REGISTER_REPORTs
 **************************************************************************/

/*
 * si470x_get_report - receive a HID report
 */
static int si470x_get_report(struct si470x_device *radio, void *buf, int size)
{
    unsigned char *report = (unsigned char *) buf;
    int retval;

    retval = usb_control_msg(radio->usbdev,
        usb_rcvctrlpipe(radio->usbdev, 0),
        HID_REQ_GET_REPORT,
        USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
        report[0], 2,
        buf, size, usb_timeout);

    if (retval < 0)
        dev_warn(&radio->intf->dev,
            "si470x_get_report: usb_control_msg returned %d\n",
            retval);
    return retval;
}


/*
 * si470x_set_report - send a HID report
 */
static int si470x_set_report(struct si470x_device *radio, void *buf, int size)
{
    unsigned char *report = (unsigned char *) buf;
    int retval;

    retval = usb_control_msg(radio->usbdev,
        usb_sndctrlpipe(radio->usbdev, 0),
        HID_REQ_SET_REPORT,
        USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
        report[0], 2,
        buf, size, usb_timeout);

    if (retval < 0)
        dev_warn(&radio->intf->dev,
            "si470x_set_report: usb_control_msg returned %d\n",
            retval);
    return retval;
}


/*
 * si470x_get_register - read register
 */
int si470x_get_register(struct si470x_device *radio, int regnr)
{
    unsigned char buf[REGISTER_REPORT_SIZE];
    int retval;

    buf[0] = REGISTER_REPORT(regnr);

    retval = si470x_get_report(radio, (void *) &buf, sizeof(buf));

    if (retval >= 0)
        radio->registers[regnr] = get_unaligned_be16(&buf[1]);

    return (retval < 0) ? -EINVAL : 0;
}


/*
 * si470x_set_register - write register
 */
int si470x_set_register(struct si470x_device *radio, int regnr)
{
    unsigned char buf[REGISTER_REPORT_SIZE];
    int retval;

    buf[0] = REGISTER_REPORT(regnr);
    put_unaligned_be16(radio->registers[regnr], &buf[1]);

    retval = si470x_set_report(radio, (void *) &buf, sizeof(buf));

    return (retval < 0) ? -EINVAL : 0;
}



/**************************************************************************
 * General Driver Functions - ENTIRE_REPORT
 **************************************************************************/

/*
 * si470x_get_all_registers - read entire registers
 */
static int si470x_get_all_registers(struct si470x_device *radio)
{
    unsigned char buf[ENTIRE_REPORT_SIZE];
    int retval;
    unsigned char regnr;

    buf[0] = ENTIRE_REPORT;

    retval = si470x_get_report(radio, (void *) &buf, sizeof(buf));

    if (retval >= 0)
        for (regnr = 0; regnr < RADIO_REGISTER_NUM; regnr++)
            radio->registers[regnr] = get_unaligned_be16(
                &buf[regnr * RADIO_REGISTER_SIZE + 1]);

    return (retval < 0) ? -EINVAL : 0;
}



/**************************************************************************
 * General Driver Functions - LED_REPORT
 **************************************************************************/

/*
 * si470x_set_led_state - sets the led state
 */
static int si470x_set_led_state(struct si470x_device *radio,
        unsigned char led_state)
{
    unsigned char buf[LED_REPORT_SIZE];
    int retval;

    buf[0] = LED_REPORT;
    buf[1] = LED_COMMAND;
    buf[2] = led_state;

    retval = si470x_set_report(radio, (void *) &buf, sizeof(buf));

    return (retval < 0) ? -EINVAL : 0;
}



/**************************************************************************
 * General Driver Functions - SCRATCH_REPORT
 **************************************************************************/

/*
 * si470x_get_scratch_versions - gets the scratch page and version infos
 */
static int si470x_get_scratch_page_versions(struct si470x_device *radio)
{
    unsigned char buf[SCRATCH_REPORT_SIZE];
    int retval;

    buf[0] = SCRATCH_REPORT;

    retval = si470x_get_report(radio, (void *) &buf, sizeof(buf));

    if (retval < 0)
        dev_warn(&radio->intf->dev, "si470x_get_scratch: "
            "si470x_get_report returned %d\n", retval);
    else {
        radio->software_version = buf[1];
        radio->hardware_version = buf[2];
    }

    return (retval < 0) ? -EINVAL : 0;
}



/**************************************************************************
 * RDS Driver Functions
 **************************************************************************/

/*
 * si470x_int_in_callback - rds callback and processing function
 *
 * TODO: do we need to use mutex locks in some sections?
 */
static void si470x_int_in_callback(struct urb *urb)
{
    struct si470x_device *radio = urb->context;
    int retval;
    unsigned char regnr;
    unsigned char blocknum;
    unsigned short bler; /* rds block errors */
    unsigned short rds;
    unsigned char tmpbuf[3];

    if (urb->status) {
        if (urb->status == -ENOENT ||
                urb->status == -ECONNRESET ||
                urb->status == -ESHUTDOWN) {
            return;
        } else {
            dev_warn(&radio->intf->dev,
             "non-zero urb status (%d)\n", urb->status);
            goto resubmit; /* Maybe we can recover. */
        }
    }

    /* Sometimes the device returns len 0 packets */
    if (urb->actual_length != RDS_REPORT_SIZE)
        goto resubmit;

    radio->registers[STATUSRSSI] =
        get_unaligned_be16(&radio->int_in_buffer[1]);

    if (radio->registers[STATUSRSSI] & STATUSRSSI_STC)
        complete(&radio->completion);

    if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS)) {
        /* Update RDS registers with URB data */
        for (regnr = 1; regnr < RDS_REGISTER_NUM; regnr++)
            radio->registers[STATUSRSSI + regnr] =
                get_unaligned_be16(&radio->int_in_buffer[
                regnr * RADIO_REGISTER_SIZE + 1]);
        /* get rds blocks */
        if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSR) == 0) {
            /* No RDS group ready, better luck next time */
            goto resubmit;
        }
        if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSS) == 0) {
            /* RDS decoder not synchronized */
            goto resubmit;
        }
        for (blocknum = 0; blocknum < 4; blocknum++) {
            switch (blocknum) {
            default:
                bler = (radio->registers[STATUSRSSI] &
                        STATUSRSSI_BLERA) >> 9;
                rds = radio->registers[RDSA];
                break;
            case 1:
                bler = (radio->registers[READCHAN] &
                        READCHAN_BLERB) >> 14;
                rds = radio->registers[RDSB];
                break;
            case 2:
                bler = (radio->registers[READCHAN] &
                        READCHAN_BLERC) >> 12;
                rds = radio->registers[RDSC];
                break;
            case 3:
                bler = (radio->registers[READCHAN] &
                        READCHAN_BLERD) >> 10;
                rds = radio->registers[RDSD];
                break;
            }

            /* Fill the V4L2 RDS buffer */
            put_unaligned_le16(rds, &tmpbuf);
            tmpbuf[2] = blocknum;       /* offset name */
            tmpbuf[2] |= blocknum << 3; /* received offset */
            if (bler > max_rds_errors)
                tmpbuf[2] |= 0x80; /* uncorrectable errors */
            else if (bler > 0)
                tmpbuf[2] |= 0x40; /* corrected error(s) */

            /* copy RDS block to internal buffer */
            memcpy(&radio->buffer[radio->wr_index], &tmpbuf, 3);
            radio->wr_index += 3;

            /* wrap write pointer */
            if (radio->wr_index >= radio->buf_size)
                radio->wr_index = 0;

            /* check for overflow */
            if (radio->wr_index == radio->rd_index) {
                /* increment and wrap read pointer */
                radio->rd_index += 3;
                if (radio->rd_index >= radio->buf_size)
                    radio->rd_index = 0;
            }
        }
        if (radio->wr_index != radio->rd_index)
            wake_up_interruptible(&radio->read_queue);
    }

resubmit:
    /* Resubmit if we're still running. */
    if (radio->int_in_running && radio->usbdev) {
        retval = usb_submit_urb(radio->int_in_urb, GFP_ATOMIC);
        if (retval) {
            dev_warn(&radio->intf->dev,
                   "resubmitting urb failed (%d)", retval);
            radio->int_in_running = 0;
        }
    }
    radio->status_rssi_auto_update = radio->int_in_running;
}


int si470x_fops_open(struct file *file)
{
    return v4l2_fh_open(file);
}

int si470x_fops_release(struct file *file)
{
    return v4l2_fh_release(file);
}

static void si470x_usb_release(struct v4l2_device *v4l2_dev)
{
    struct si470x_device *radio =
        container_of(v4l2_dev, struct si470x_device, v4l2_dev);

    usb_free_urb(radio->int_in_urb);
    v4l2_ctrl_handler_free(&radio->hdl);
    v4l2_device_unregister(&radio->v4l2_dev);
    kfree(radio->int_in_buffer);
    kfree(radio->buffer);
    kfree(radio);
}


/**************************************************************************
 * Video4Linux Interface
 **************************************************************************/

/*
 * si470x_vidioc_querycap - query device capabilities
 */
int si470x_vidioc_querycap(struct file *file, void *priv,
        struct v4l2_capability *capability)
{
    struct si470x_device *radio = video_drvdata(file);

    strlcpy(capability->driver, DRIVER_NAME, sizeof(capability->driver));
    strlcpy(capability->card, DRIVER_CARD, sizeof(capability->card));
    usb_make_path(radio->usbdev, capability->bus_info,
            sizeof(capability->bus_info));
    capability->device_caps = V4L2_CAP_HW_FREQ_SEEK | V4L2_CAP_READWRITE |
        V4L2_CAP_TUNER | V4L2_CAP_RADIO | V4L2_CAP_RDS_CAPTURE;
    capability->capabilities = capability->device_caps | V4L2_CAP_DEVICE_CAPS;
    return 0;
}


static int si470x_start_usb(struct si470x_device *radio)
{
    int retval;

    /* initialize interrupt urb */
    usb_fill_int_urb(radio->int_in_urb, radio->usbdev,
            usb_rcvintpipe(radio->usbdev,
                radio->int_in_endpoint->bEndpointAddress),
            radio->int_in_buffer,
            le16_to_cpu(radio->int_in_endpoint->wMaxPacketSize),
            si470x_int_in_callback,
            radio,
            radio->int_in_endpoint->bInterval);

    radio->int_in_running = 1;
    mb();

    retval = usb_submit_urb(radio->int_in_urb, GFP_KERNEL);
    if (retval) {
        dev_info(&radio->intf->dev,
                "submitting int urb failed (%d)\n", retval);
        radio->int_in_running = 0;
    }
    radio->status_rssi_auto_update = radio->int_in_running;

    /* start radio */
    retval = si470x_start(radio);
    if (retval < 0)
        return retval;

    v4l2_ctrl_handler_setup(&radio->hdl);

    return retval;
}

/**************************************************************************
 * USB Interface
 **************************************************************************/

/*
 * si470x_usb_driver_probe - probe for the device
 */
static int si470x_usb_driver_probe(struct usb_interface *intf,
        const struct usb_device_id *id)
{
    struct si470x_device *radio;
    struct usb_host_interface *iface_desc;
    struct usb_endpoint_descriptor *endpoint;
    int i, int_end_size, retval = 0;
    unsigned char version_warning = 0;

    /* private data allocation and initialization */
    radio = kzalloc(sizeof(struct si470x_device), GFP_KERNEL);
    if (!radio) {
        retval = -ENOMEM;
        goto err_initial;
    }
    radio->usbdev = interface_to_usbdev(intf);
    radio->intf = intf;
    radio->band = 1; /* Default to 76 - 108 MHz */
    mutex_init(&radio->lock);
    init_completion(&radio->completion);

    iface_desc = intf->cur_altsetting;

    /* Set up interrupt endpoint information. */
    for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
        endpoint = &iface_desc->endpoint[i].desc;
        if (((endpoint->bEndpointAddress & USB_ENDPOINT_DIR_MASK) ==
         USB_DIR_IN) && ((endpoint->bmAttributes &
         USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT))
            radio->int_in_endpoint = endpoint;
    }
    if (!radio->int_in_endpoint) {
        dev_info(&intf->dev, "could not find interrupt in endpoint\n");
        retval = -EIO;
        goto err_radio;
    }

    int_end_size = le16_to_cpu(radio->int_in_endpoint->wMaxPacketSize);

    radio->int_in_buffer = kmalloc(int_end_size, GFP_KERNEL);
    if (!radio->int_in_buffer) {
        dev_info(&intf->dev, "could not allocate int_in_buffer");
        retval = -ENOMEM;
        goto err_radio;
    }

    radio->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
    if (!radio->int_in_urb) {
        dev_info(&intf->dev, "could not allocate int_in_urb");
        retval = -ENOMEM;
        goto err_intbuffer;
    }

    radio->v4l2_dev.release = si470x_usb_release;
    retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
    if (retval < 0) {
        dev_err(&intf->dev, "couldn't register v4l2_device\n");
        goto err_urb;
    }

    v4l2_ctrl_handler_init(&radio->hdl, 2);
    v4l2_ctrl_new_std(&radio->hdl, &si470x_ctrl_ops,
              V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
    v4l2_ctrl_new_std(&radio->hdl, &si470x_ctrl_ops,
              V4L2_CID_AUDIO_VOLUME, 0, 15, 1, 15);
    if (radio->hdl.error) {
        retval = radio->hdl.error;
        dev_err(&intf->dev, "couldn't register control\n");
        goto err_dev;
    }
    radio->videodev = si470x_viddev_template;
    radio->videodev.ctrl_handler = &radio->hdl;
    radio->videodev.lock = &radio->lock;
    radio->videodev.v4l2_dev = &radio->v4l2_dev;
    radio->videodev.release = video_device_release_empty;
    set_bit(V4L2_FL_USE_FH_PRIO, &radio->videodev.flags);
    video_set_drvdata(&radio->videodev, radio);

    /* get device and chip versions */
    if (si470x_get_all_registers(radio) < 0) {
        retval = -EIO;
        goto err_ctrl;
    }
    dev_info(&intf->dev, "DeviceID=0x%4.4hx ChipID=0x%4.4hx\n",
            radio->registers[DEVICEID], radio->registers[CHIPID]);
    if ((radio->registers[CHIPID] & CHIPID_FIRMWARE) < RADIO_FW_VERSION) {
        dev_warn(&intf->dev,
            "This driver is known to work with "
            "firmware version %hu,\n", RADIO_FW_VERSION);
        dev_warn(&intf->dev,
            "but the device has firmware version %hu.\n",
            radio->registers[CHIPID] & CHIPID_FIRMWARE);
        version_warning = 1;
    }

    /* get software and hardware versions */
    if (si470x_get_scratch_page_versions(radio) < 0) {
        retval = -EIO;
        goto err_ctrl;
    }
    dev_info(&intf->dev, "software version %d, hardware version %d\n",
            radio->software_version, radio->hardware_version);
    if (radio->software_version < RADIO_SW_VERSION) {
        dev_warn(&intf->dev,
            "This driver is known to work with "
            "software version %hu,\n", RADIO_SW_VERSION);
        dev_warn(&intf->dev,
            "but the device has software version %hu.\n",
            radio->software_version);
        version_warning = 1;
    }
    if (radio->hardware_version < RADIO_HW_VERSION) {
        dev_warn(&intf->dev,
            "This driver is known to work with "
            "hardware version %hu,\n", RADIO_HW_VERSION);
        dev_warn(&intf->dev,
            "but the device has hardware version %hu.\n",
            radio->hardware_version);
        version_warning = 1;
    }

    /* give out version warning */
    if (version_warning == 1) {
        dev_warn(&intf->dev,
            "If you have some trouble using this driver,\n");
        dev_warn(&intf->dev,
            "please report to V4L ML at "
            "[email protected]\n");
    }

    /* set led to connect state */
    si470x_set_led_state(radio, BLINK_GREEN_LED);

    /* rds buffer allocation */
    radio->buf_size = rds_buf * 3;
    radio->buffer = kmalloc(radio->buf_size, GFP_KERNEL);
    if (!radio->buffer) {
        retval = -EIO;
        goto err_ctrl;
    }

    /* rds buffer configuration */
    radio->wr_index = 0;
    radio->rd_index = 0;
    init_waitqueue_head(&radio->read_queue);
    usb_set_intfdata(intf, radio);

    /* start radio */
    retval = si470x_start_usb(radio);
    if (retval < 0)
        goto err_all;

    /* set initial frequency */
    si470x_set_freq(radio, 87.5 * FREQ_MUL); /* available in all regions */

    /* register video device */
    retval = video_register_device(&radio->videodev, VFL_TYPE_RADIO,
            radio_nr);
    if (retval) {
        dev_err(&intf->dev, "Could not register video device\n");
        goto err_all;
    }

    return 0;
err_all:
    kfree(radio->buffer);
err_ctrl:
    v4l2_ctrl_handler_free(&radio->hdl);
err_dev:
    v4l2_device_unregister(&radio->v4l2_dev);
err_urb:
    usb_free_urb(radio->int_in_urb);
err_intbuffer:
    kfree(radio->int_in_buffer);
err_radio:
    kfree(radio);
err_initial:
    return retval;
}


/*
 * si470x_usb_driver_suspend - suspend the device
 */
static int si470x_usb_driver_suspend(struct usb_interface *intf,
        pm_message_t message)
{
    struct si470x_device *radio = usb_get_intfdata(intf);

    dev_info(&intf->dev, "suspending now...\n");

    /* shutdown interrupt handler */
    if (radio->int_in_running) {
        radio->int_in_running = 0;
        if (radio->int_in_urb)
            usb_kill_urb(radio->int_in_urb);
    }

    /* cancel read processes */
    wake_up_interruptible(&radio->read_queue);

    /* stop radio */
    si470x_stop(radio);
    return 0;
}


/*
 * si470x_usb_driver_resume - resume the device
 */
static int si470x_usb_driver_resume(struct usb_interface *intf)
{
    struct si470x_device *radio = usb_get_intfdata(intf);
    int ret;

    dev_info(&intf->dev, "resuming now...\n");

    /* start radio */
    ret = si470x_start_usb(radio);
    if (ret == 0)
        v4l2_ctrl_handler_setup(&radio->hdl);

    return ret;
}


/*
 * si470x_usb_driver_disconnect - disconnect the device
 */
static void si470x_usb_driver_disconnect(struct usb_interface *intf)
{
    struct si470x_device *radio = usb_get_intfdata(intf);

    mutex_lock(&radio->lock);
    v4l2_device_disconnect(&radio->v4l2_dev);
    video_unregister_device(&radio->videodev);
    usb_set_intfdata(intf, NULL);
    mutex_unlock(&radio->lock);
    v4l2_device_put(&radio->v4l2_dev);
}


/*
 * si470x_usb_driver - usb driver interface
 *
 * A note on suspend/resume: this driver had only empty suspend/resume
 * functions, and when I tried to test suspend/resume it always disconnected
 * instead of resuming (using my ADS InstantFM stick). So I've decided to
 * remove these callbacks until someone else with better hardware can
 * implement and test this.
 */
static struct usb_driver si470x_usb_driver = {
    .name           = DRIVER_NAME,
    .probe          = si470x_usb_driver_probe,
    .disconnect     = si470x_usb_driver_disconnect,
    .suspend        = si470x_usb_driver_suspend,
    .resume         = si470x_usb_driver_resume,
    .reset_resume       = si470x_usb_driver_resume,
    .id_table       = si470x_usb_driver_id_table,
};

module_usb_driver(si470x_usb_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_VERSION(DRIVER_VERSION);