fmdrv_v4l2.c

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/*
 *  FM Driver for Connectivity chip of Texas Instruments.
 *  This file provides interfaces to V4L2 subsystem.
 *
 *  This module registers with V4L2 subsystem as Radio
 *  data system interface (/dev/radio). During the registration,
 *  it will expose two set of function pointers.
 *
 *    1) File operation related API (open, close, read, write, poll...etc).
 *    2) Set of V4L2 IOCTL complaint API.
 *
 *  Copyright (C) 2011 Texas Instruments
 *  Author: Raja Mani <[email protected]>
 *  Author: Manjunatha Halli <[email protected]>
 *
 *  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include <linux/export.h>

#include "fmdrv.h"
#include "fmdrv_v4l2.h"
#include "fmdrv_common.h"
#include "fmdrv_rx.h"
#include "fmdrv_tx.h"

static struct video_device *gradio_dev;
static u8 radio_disconnected;

/* -- V4L2 RADIO (/dev/radioX) device file operation interfaces --- */

/* Read RX RDS data */
static ssize_t fm_v4l2_fops_read(struct file *file, char __user * buf,
                    size_t count, loff_t *ppos)
{
    u8 rds_mode;
    int ret;
    struct fmdev *fmdev;

    fmdev = video_drvdata(file);

    if (!radio_disconnected) {
        fmerr("FM device is already disconnected\n");
        return -EIO;
    }

    if (mutex_lock_interruptible(&fmdev->mutex))
        return -ERESTARTSYS;

    /* Turn on RDS mode if it is disabled */
    ret = fm_rx_get_rds_mode(fmdev, &rds_mode);
    if (ret < 0) {
        fmerr("Unable to read current rds mode\n");
        goto read_unlock;
    }

    if (rds_mode == FM_RDS_DISABLE) {
        ret = fmc_set_rds_mode(fmdev, FM_RDS_ENABLE);
        if (ret < 0) {
            fmerr("Failed to enable rds mode\n");
            goto read_unlock;
        }
    }

    /* Copy RDS data from internal buffer to user buffer */
    ret = fmc_transfer_rds_from_internal_buff(fmdev, file, buf, count);
read_unlock:
    mutex_unlock(&fmdev->mutex);
    return ret;
}

/* Write TX RDS data */
static ssize_t fm_v4l2_fops_write(struct file *file, const char __user * buf,
        size_t count, loff_t *ppos)
{
    struct tx_rds rds;
    int ret;
    struct fmdev *fmdev;

    ret = copy_from_user(&rds, buf, sizeof(rds));
    rds.text[sizeof(rds.text) - 1] = '\0';
    fmdbg("(%d)type: %d, text %s, af %d\n",
           ret, rds.text_type, rds.text, rds.af_freq);
    if (ret)
        return -EFAULT;

    fmdev = video_drvdata(file);
    if (mutex_lock_interruptible(&fmdev->mutex))
        return -ERESTARTSYS;
    fm_tx_set_radio_text(fmdev, rds.text, rds.text_type);
    fm_tx_set_af(fmdev, rds.af_freq);
    mutex_unlock(&fmdev->mutex);

    return sizeof(rds);
}

static u32 fm_v4l2_fops_poll(struct file *file, struct poll_table_struct *pts)
{
    int ret;
    struct fmdev *fmdev;

    fmdev = video_drvdata(file);
    mutex_lock(&fmdev->mutex);
    ret = fmc_is_rds_data_available(fmdev, file, pts);
    mutex_unlock(&fmdev->mutex);
    if (ret < 0)
        return POLLIN | POLLRDNORM;

    return 0;
}

/*
 * Handle open request for "/dev/radioX" device.
 * Start with FM RX mode as default.
 */
static int fm_v4l2_fops_open(struct file *file)
{
    int ret;
    struct fmdev *fmdev = NULL;

    /* Don't allow multiple open */
    if (radio_disconnected) {
        fmerr("FM device is already opened\n");
        return -EBUSY;
    }

    fmdev = video_drvdata(file);

    if (mutex_lock_interruptible(&fmdev->mutex))
        return -ERESTARTSYS;
    ret = fmc_prepare(fmdev);
    if (ret < 0) {
        fmerr("Unable to prepare FM CORE\n");
        goto open_unlock;
    }

    fmdbg("Load FM RX firmware..\n");

    ret = fmc_set_mode(fmdev, FM_MODE_RX);
    if (ret < 0) {
        fmerr("Unable to load FM RX firmware\n");
        goto open_unlock;
    }
    radio_disconnected = 1;

open_unlock:
    mutex_unlock(&fmdev->mutex);
    return ret;
}

static int fm_v4l2_fops_release(struct file *file)
{
    int ret;
    struct fmdev *fmdev;

    fmdev = video_drvdata(file);
    if (!radio_disconnected) {
        fmdbg("FM device is already closed\n");
        return 0;
    }

    mutex_lock(&fmdev->mutex);
    ret = fmc_set_mode(fmdev, FM_MODE_OFF);
    if (ret < 0) {
        fmerr("Unable to turn off the chip\n");
        goto release_unlock;
    }

    ret = fmc_release(fmdev);
    if (ret < 0) {
        fmerr("FM CORE release failed\n");
        goto release_unlock;
    }
    radio_disconnected = 0;

release_unlock:
    mutex_unlock(&fmdev->mutex);
    return ret;
}

/* V4L2 RADIO (/dev/radioX) device IOCTL interfaces */
static int fm_v4l2_vidioc_querycap(struct file *file, void *priv,
        struct v4l2_capability *capability)
{
    strlcpy(capability->driver, FM_DRV_NAME, sizeof(capability->driver));
    strlcpy(capability->card, FM_DRV_CARD_SHORT_NAME,
            sizeof(capability->card));
    sprintf(capability->bus_info, "UART");
    capability->capabilities = V4L2_CAP_HW_FREQ_SEEK | V4L2_CAP_TUNER |
        V4L2_CAP_RADIO | V4L2_CAP_MODULATOR |
        V4L2_CAP_AUDIO | V4L2_CAP_READWRITE |
        V4L2_CAP_RDS_CAPTURE;

    return 0;
}

static int fm_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
{
    struct fmdev *fmdev = container_of(ctrl->handler,
            struct fmdev, ctrl_handler);

    switch (ctrl->id) {
    case  V4L2_CID_TUNE_ANTENNA_CAPACITOR:
        ctrl->val = fm_tx_get_tune_cap_val(fmdev);
        break;
    default:
        fmwarn("%s: Unknown IOCTL: %d\n", __func__, ctrl->id);
        break;
    }

    return 0;
}

static int fm_v4l2_s_ctrl(struct v4l2_ctrl *ctrl)
{
    struct fmdev *fmdev = container_of(ctrl->handler,
            struct fmdev, ctrl_handler);

    switch (ctrl->id) {
    case V4L2_CID_AUDIO_VOLUME: /* set volume */
        return fm_rx_set_volume(fmdev, (u16)ctrl->val);

    case V4L2_CID_AUDIO_MUTE:   /* set mute */
        return fmc_set_mute_mode(fmdev, (u8)ctrl->val);

    case V4L2_CID_TUNE_POWER_LEVEL:
        /* set TX power level - ext control */
        return fm_tx_set_pwr_lvl(fmdev, (u8)ctrl->val);

    case V4L2_CID_TUNE_PREEMPHASIS:
        return fm_tx_set_preemph_filter(fmdev, (u8) ctrl->val);

    default:
        return -EINVAL;
    }
}

static int fm_v4l2_vidioc_g_audio(struct file *file, void *priv,
        struct v4l2_audio *audio)
{
    memset(audio, 0, sizeof(*audio));
    strcpy(audio->name, "Radio");
    audio->capability = V4L2_AUDCAP_STEREO;

    return 0;
}

static int fm_v4l2_vidioc_s_audio(struct file *file, void *priv,
        const struct v4l2_audio *audio)
{
    if (audio->index != 0)
        return -EINVAL;

    return 0;
}

/* Get tuner attributes. If current mode is NOT RX, return error */
static int fm_v4l2_vidioc_g_tuner(struct file *file, void *priv,
        struct v4l2_tuner *tuner)
{
    struct fmdev *fmdev = video_drvdata(file);
    u32 bottom_freq;
    u32 top_freq;
    u16 stereo_mono_mode;
    u16 rssilvl;
    int ret;

    if (tuner->index != 0)
        return -EINVAL;

    if (fmdev->curr_fmmode != FM_MODE_RX)
        return -EPERM;

    ret = fm_rx_get_band_freq_range(fmdev, &bottom_freq, &top_freq);
    if (ret != 0)
        return ret;

    ret = fm_rx_get_stereo_mono(fmdev, &stereo_mono_mode);
    if (ret != 0)
        return ret;

    ret = fm_rx_get_rssi_level(fmdev, &rssilvl);
    if (ret != 0)
        return ret;

    strcpy(tuner->name, "FM");
    tuner->type = V4L2_TUNER_RADIO;
    /* Store rangelow and rangehigh freq in unit of 62.5 Hz */
    tuner->rangelow = bottom_freq * 16;
    tuner->rangehigh = top_freq * 16;
    tuner->rxsubchans = V4L2_TUNER_SUB_MONO | V4L2_TUNER_SUB_STEREO |
    ((fmdev->rx.rds.flag == FM_RDS_ENABLE) ? V4L2_TUNER_SUB_RDS : 0);
    tuner->capability = V4L2_TUNER_CAP_STEREO | V4L2_TUNER_CAP_RDS |
                V4L2_TUNER_CAP_LOW |
                V4L2_TUNER_CAP_HWSEEK_BOUNDED |
                V4L2_TUNER_CAP_HWSEEK_WRAP;
    tuner->audmode = (stereo_mono_mode ?
              V4L2_TUNER_MODE_MONO : V4L2_TUNER_MODE_STEREO);

    /*
     * Actual rssi value lies in between -128 to +127.
     * Convert this range from 0 to 255 by adding +128
     */
    rssilvl += 128;

    /*
     * Return signal strength value should be within 0 to 65535.
     * Find out correct signal radio by multiplying (65535/255) = 257
     */
    tuner->signal = rssilvl * 257;
    tuner->afc = 0;

    return ret;
}

/*
 * Set tuner attributes. If current mode is NOT RX, set to RX.
 * Currently, we set only audio mode (mono/stereo) and RDS state (on/off).
 * Should we set other tuner attributes, too?
 */
static int fm_v4l2_vidioc_s_tuner(struct file *file, void *priv,
        struct v4l2_tuner *tuner)
{
    struct fmdev *fmdev = video_drvdata(file);
    u16 aud_mode;
    u8 rds_mode;
    int ret;

    if (tuner->index != 0)
        return -EINVAL;

    aud_mode = (tuner->audmode == V4L2_TUNER_MODE_STEREO) ?
            FM_STEREO_MODE : FM_MONO_MODE;
    rds_mode = (tuner->rxsubchans & V4L2_TUNER_SUB_RDS) ?
            FM_RDS_ENABLE : FM_RDS_DISABLE;

    if (fmdev->curr_fmmode != FM_MODE_RX) {
        ret = fmc_set_mode(fmdev, FM_MODE_RX);
        if (ret < 0) {
            fmerr("Failed to set RX mode\n");
            return ret;
        }
    }

    ret = fmc_set_stereo_mono(fmdev, aud_mode);
    if (ret < 0) {
        fmerr("Failed to set RX stereo/mono mode\n");
        return ret;
    }

    ret = fmc_set_rds_mode(fmdev, rds_mode);
    if (ret < 0)
        fmerr("Failed to set RX RDS mode\n");

    return ret;
}

/* Get tuner or modulator radio frequency */
static int fm_v4l2_vidioc_g_freq(struct file *file, void *priv,
        struct v4l2_frequency *freq)
{
    struct fmdev *fmdev = video_drvdata(file);
    int ret;

    ret = fmc_get_freq(fmdev, &freq->frequency);
    if (ret < 0) {
        fmerr("Failed to get frequency\n");
        return ret;
    }

    /* Frequency unit of 62.5 Hz*/
    freq->frequency = (u32) freq->frequency * 16;

    return 0;
}

/* Set tuner or modulator radio frequency */
static int fm_v4l2_vidioc_s_freq(struct file *file, void *priv,
        struct v4l2_frequency *freq)
{
    struct fmdev *fmdev = video_drvdata(file);

    /*
     * As V4L2_TUNER_CAP_LOW is set 1 user sends the frequency
     * in units of 62.5 Hz.
     */
    freq->frequency = (u32)(freq->frequency / 16);

    return fmc_set_freq(fmdev, freq->frequency);
}

/* Set hardware frequency seek. If current mode is NOT RX, set it RX. */
static int fm_v4l2_vidioc_s_hw_freq_seek(struct file *file, void *priv,
        const struct v4l2_hw_freq_seek *seek)
{
    struct fmdev *fmdev = video_drvdata(file);
    int ret;

    if (file->f_flags & O_NONBLOCK)
        return -EWOULDBLOCK;

    if (fmdev->curr_fmmode != FM_MODE_RX) {
        ret = fmc_set_mode(fmdev, FM_MODE_RX);
        if (ret != 0) {
            fmerr("Failed to set RX mode\n");
            return ret;
        }
    }

    ret = fm_rx_seek(fmdev, seek->seek_upward, seek->wrap_around,
            seek->spacing);
    if (ret < 0)
        fmerr("RX seek failed - %d\n", ret);

    return ret;
}
/* Get modulator attributes. If mode is not TX, return no attributes. */
static int fm_v4l2_vidioc_g_modulator(struct file *file, void *priv,
        struct v4l2_modulator *mod)
{
    struct fmdev *fmdev = video_drvdata(file);

    if (mod->index != 0)
        return -EINVAL;

    if (fmdev->curr_fmmode != FM_MODE_TX)
        return -EPERM;

    mod->txsubchans = ((fmdev->tx_data.aud_mode == FM_STEREO_MODE) ?
                V4L2_TUNER_SUB_STEREO : V4L2_TUNER_SUB_MONO) |
                ((fmdev->tx_data.rds.flag == FM_RDS_ENABLE) ?
                V4L2_TUNER_SUB_RDS : 0);

    mod->capability = V4L2_TUNER_CAP_STEREO | V4L2_TUNER_CAP_RDS |
                V4L2_TUNER_CAP_LOW;

    return 0;
}

/* Set modulator attributes. If mode is not TX, set to TX. */
static int fm_v4l2_vidioc_s_modulator(struct file *file, void *priv,
        const struct v4l2_modulator *mod)
{
    struct fmdev *fmdev = video_drvdata(file);
    u8 rds_mode;
    u16 aud_mode;
    int ret;

    if (mod->index != 0)
        return -EINVAL;

    if (fmdev->curr_fmmode != FM_MODE_TX) {
        ret = fmc_set_mode(fmdev, FM_MODE_TX);
        if (ret != 0) {
            fmerr("Failed to set TX mode\n");
            return ret;
        }
    }

    aud_mode = (mod->txsubchans & V4L2_TUNER_SUB_STEREO) ?
            FM_STEREO_MODE : FM_MONO_MODE;
    rds_mode = (mod->txsubchans & V4L2_TUNER_SUB_RDS) ?
            FM_RDS_ENABLE : FM_RDS_DISABLE;
    ret = fm_tx_set_stereo_mono(fmdev, aud_mode);
    if (ret < 0) {
        fmerr("Failed to set mono/stereo mode for TX\n");
        return ret;
    }
    ret = fm_tx_set_rds_mode(fmdev, rds_mode);
    if (ret < 0)
        fmerr("Failed to set rds mode for TX\n");

    return ret;
}

static const struct v4l2_file_operations fm_drv_fops = {
    .owner = THIS_MODULE,
    .read = fm_v4l2_fops_read,
    .write = fm_v4l2_fops_write,
    .poll = fm_v4l2_fops_poll,
    .unlocked_ioctl = video_ioctl2,
    .open = fm_v4l2_fops_open,
    .release = fm_v4l2_fops_release,
};

static const struct v4l2_ctrl_ops fm_ctrl_ops = {
    .s_ctrl = fm_v4l2_s_ctrl,
    .g_volatile_ctrl = fm_g_volatile_ctrl,
};
static const struct v4l2_ioctl_ops fm_drv_ioctl_ops = {
    .vidioc_querycap = fm_v4l2_vidioc_querycap,
    .vidioc_g_audio = fm_v4l2_vidioc_g_audio,
    .vidioc_s_audio = fm_v4l2_vidioc_s_audio,
    .vidioc_g_tuner = fm_v4l2_vidioc_g_tuner,
    .vidioc_s_tuner = fm_v4l2_vidioc_s_tuner,
    .vidioc_g_frequency = fm_v4l2_vidioc_g_freq,
    .vidioc_s_frequency = fm_v4l2_vidioc_s_freq,
    .vidioc_s_hw_freq_seek = fm_v4l2_vidioc_s_hw_freq_seek,
    .vidioc_g_modulator = fm_v4l2_vidioc_g_modulator,
    .vidioc_s_modulator = fm_v4l2_vidioc_s_modulator
};

/* V4L2 RADIO device parent structure */
static struct video_device fm_viddev_template = {
    .fops = &fm_drv_fops,
    .ioctl_ops = &fm_drv_ioctl_ops,
    .name = FM_DRV_NAME,
    .release = video_device_release,
};

int fm_v4l2_init_video_device(struct fmdev *fmdev, int radio_nr)
{
    struct v4l2_ctrl *ctrl;
    int ret;

    /* Init mutex for core locking */
    mutex_init(&fmdev->mutex);

    /* Allocate new video device */
    gradio_dev = video_device_alloc();
    if (NULL == gradio_dev) {
        fmerr("Can't allocate video device\n");
        return -ENOMEM;
    }

    /* Setup FM driver's V4L2 properties */
    memcpy(gradio_dev, &fm_viddev_template, sizeof(fm_viddev_template));

    video_set_drvdata(gradio_dev, fmdev);

    gradio_dev->lock = &fmdev->mutex;

    /* Register with V4L2 subsystem as RADIO device */
    if (video_register_device(gradio_dev, VFL_TYPE_RADIO, radio_nr)) {
        video_device_release(gradio_dev);
        fmerr("Could not register video device\n");
        return -ENOMEM;
    }

    fmdev->radio_dev = gradio_dev;

    /* Register to v4l2 ctrl handler framework */
    fmdev->radio_dev->ctrl_handler = &fmdev->ctrl_handler;

    ret = v4l2_ctrl_handler_init(&fmdev->ctrl_handler, 5);
    if (ret < 0) {
        fmerr("(fmdev): Can't init ctrl handler\n");
        v4l2_ctrl_handler_free(&fmdev->ctrl_handler);
        return -EBUSY;
    }

    /*
     * Following controls are handled by V4L2 control framework.
     * Added in ascending ID order.
     */
    v4l2_ctrl_new_std(&fmdev->ctrl_handler, &fm_ctrl_ops,
            V4L2_CID_AUDIO_VOLUME, FM_RX_VOLUME_MIN,
            FM_RX_VOLUME_MAX, 1, FM_RX_VOLUME_MAX);

    v4l2_ctrl_new_std(&fmdev->ctrl_handler, &fm_ctrl_ops,
            V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);

    v4l2_ctrl_new_std_menu(&fmdev->ctrl_handler, &fm_ctrl_ops,
            V4L2_CID_TUNE_PREEMPHASIS, V4L2_PREEMPHASIS_75_uS,
            0, V4L2_PREEMPHASIS_75_uS);

    v4l2_ctrl_new_std(&fmdev->ctrl_handler, &fm_ctrl_ops,
            V4L2_CID_TUNE_POWER_LEVEL, FM_PWR_LVL_LOW,
            FM_PWR_LVL_HIGH, 1, FM_PWR_LVL_HIGH);

    ctrl = v4l2_ctrl_new_std(&fmdev->ctrl_handler, &fm_ctrl_ops,
            V4L2_CID_TUNE_ANTENNA_CAPACITOR, 0,
            255, 1, 255);

    if (ctrl)
        ctrl->flags |= V4L2_CTRL_FLAG_VOLATILE;

    return 0;
}

void *fm_v4l2_deinit_video_device(void)
{
    struct fmdev *fmdev;


    fmdev = video_get_drvdata(gradio_dev);

    /* Unregister to v4l2 ctrl handler framework*/
    v4l2_ctrl_handler_free(&fmdev->ctrl_handler);

    /* Unregister RADIO device from V4L2 subsystem */
    video_unregister_device(gradio_dev);

    return fmdev;
}