drivers/media/radio/wl128x/fmdrv_v4l2.c - third_party/linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  *  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 <raja_mani@ti.com>
  *  Author: Manjunatha Halli <manjunatha_halli@ti.com>
  */

 #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 __poll_t 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 EPOLLIN | EPOLLRDNORM;

 	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)
 {
 	strscpy(capability->driver, FM_DRV_NAME, sizeof(capability->driver));
 	strscpy(capability->card, FM_DRV_CARD_SHORT_NAME,
 		sizeof(capability->card));
 	sprintf(capability->bus_info, "UART");
 	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));
 	strscpy(audio->name, "Radio", sizeof(audio->name));
 	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;

 	strscpy(tuner->name, "FM", sizeof(tuner->name));
 	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,
 		const 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,
 		const 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.
 	 */
 	return fmc_set_freq(fmdev, freq->frequency / 16);
 }

 /* 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 const struct video_device fm_viddev_template = {
 	.fops = &fm_drv_fops,
 	.ioctl_ops = &fm_drv_ioctl_ops,
 	.name = FM_DRV_NAME,
 	.release = video_device_release_empty,
 	/*
 	 * To ensure both the tuner and modulator ioctls are accessible we
 	 * set the vfl_dir to M2M to indicate this.
 	 *
 	 * It is not really a mem2mem device of course, but it can both receive
 	 * and transmit using the same radio device. It's the only radio driver
 	 * that does this and it should really be split in two radio devices,
 	 * but that would affect applications using this driver.
 	 */
 	.vfl_dir = VFL_DIR_M2M,
 	.device_caps = V4L2_CAP_HW_FREQ_SEEK | V4L2_CAP_TUNER | V4L2_CAP_RADIO |
 		       V4L2_CAP_MODULATOR | V4L2_CAP_AUDIO |
 		       V4L2_CAP_READWRITE | V4L2_CAP_RDS_CAPTURE,
 };

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

 	strscpy(fmdev->v4l2_dev.name, FM_DRV_NAME,
 		sizeof(fmdev->v4l2_dev.name));
 	ret = v4l2_device_register(NULL, &fmdev->v4l2_dev);
 	if (ret < 0)
 		return ret;

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

 	/* Setup FM driver's V4L2 properties */
 	gradio_dev = fm_viddev_template;

 	video_set_drvdata(&gradio_dev, fmdev);

 	gradio_dev.lock = &fmdev->mutex;
 	gradio_dev.v4l2_dev = &fmdev->v4l2_dev;

 	/* Register with V4L2 subsystem as RADIO device */
 	if (video_register_device(&gradio_dev, VFL_TYPE_RADIO, radio_nr)) {
 		v4l2_device_unregister(&fmdev->v4l2_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);
 		video_unregister_device(fmdev->radio_dev);
 		v4l2_device_unregister(&fmdev->v4l2_dev);
 		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);

 	v4l2_device_unregister(&fmdev->v4l2_dev);

 	return fmdev;
 }
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* 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 <raja_mani@ti.com>
	* Author: Manjunatha Halli <manjunatha_halli@ti.com>
	*/

	#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 __poll_t 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 EPOLLIN \| EPOLLRDNORM;

	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)
	{
	strscpy(capability->driver, FM_DRV_NAME, sizeof(capability->driver));
	strscpy(capability->card, FM_DRV_CARD_SHORT_NAME,
	sizeof(capability->card));
	sprintf(capability->bus_info, "UART");
	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));
	strscpy(audio->name, "Radio", sizeof(audio->name));
	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;

	strscpy(tuner->name, "FM", sizeof(tuner->name));
	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,
	const 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,
	const 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.
	*/
	return fmc_set_freq(fmdev, freq->frequency / 16);
	}

	/* 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 const struct video_device fm_viddev_template = {
	.fops = &fm_drv_fops,
	.ioctl_ops = &fm_drv_ioctl_ops,
	.name = FM_DRV_NAME,
	.release = video_device_release_empty,
	/*
	* To ensure both the tuner and modulator ioctls are accessible we
	* set the vfl_dir to M2M to indicate this.
	*
	* It is not really a mem2mem device of course, but it can both receive
	* and transmit using the same radio device. It's the only radio driver
	* that does this and it should really be split in two radio devices,
	* but that would affect applications using this driver.
	*/
	.vfl_dir = VFL_DIR_M2M,
	.device_caps = V4L2_CAP_HW_FREQ_SEEK \| V4L2_CAP_TUNER \| V4L2_CAP_RADIO \|
	V4L2_CAP_MODULATOR \| V4L2_CAP_AUDIO \|
	V4L2_CAP_READWRITE \| V4L2_CAP_RDS_CAPTURE,
	};

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

	strscpy(fmdev->v4l2_dev.name, FM_DRV_NAME,
	sizeof(fmdev->v4l2_dev.name));
	ret = v4l2_device_register(NULL, &fmdev->v4l2_dev);
	if (ret < 0)
	return ret;

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

	/* Setup FM driver's V4L2 properties */
	gradio_dev = fm_viddev_template;

	video_set_drvdata(&gradio_dev, fmdev);

	gradio_dev.lock = &fmdev->mutex;
	gradio_dev.v4l2_dev = &fmdev->v4l2_dev;

	/* Register with V4L2 subsystem as RADIO device */
	if (video_register_device(&gradio_dev, VFL_TYPE_RADIO, radio_nr)) {
	v4l2_device_unregister(&fmdev->v4l2_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);
	video_unregister_device(fmdev->radio_dev);
	v4l2_device_unregister(&fmdev->v4l2_dev);
	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);

	v4l2_device_unregister(&fmdev->v4l2_dev);

	return fmdev;
	}