/*
   * drivers/media/radio/si4713-i2c.c
   *
   * Silicon Labs Si4713 FM Radio Transmitter I2C commands.
   *
   * Copyright (c) 2009 Nokia Corporation
   * Contact: Eduardo Valentin <eduardo.valentin@nokia.com>
   *
   * 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
   */
  
  #include <linux/completion.h>
  #include <linux/delay.h>
  #include <linux/err.h>
  #include <linux/interrupt.h>
  #include <linux/i2c.h>
  #include <linux/slab.h>
  #include <linux/gpio.h>
  #include <linux/module.h>
  #include <media/v4l2-device.h>
  #include <media/v4l2-ioctl.h>
  #include <media/v4l2-common.h>
  
  #include "si4713.h"
  
  /* module parameters */
  static int debug;
  module_param(debug, int, S_IRUGO | S_IWUSR);
  MODULE_PARM_DESC(debug, "Debug level (0 - 2)");
  
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("Eduardo Valentin <eduardo.valentin@nokia.com>");
  MODULE_DESCRIPTION("I2C driver for Si4713 FM Radio Transmitter");
  MODULE_VERSION("0.0.1");
  
  #define DEFAULT_RDS_PI			0x00
  #define DEFAULT_RDS_PTY			0x00
  #define DEFAULT_RDS_DEVIATION		0x00C8
  #define DEFAULT_RDS_PS_REPEAT_COUNT	0x0003
  #define DEFAULT_LIMITER_RTIME		0x1392
  #define DEFAULT_LIMITER_DEV		0x102CA
  #define DEFAULT_PILOT_FREQUENCY		0x4A38
  #define DEFAULT_PILOT_DEVIATION		0x1A5E
  #define DEFAULT_ACOMP_ATIME		0x0000
  #define DEFAULT_ACOMP_RTIME		0xF4240L
  #define DEFAULT_ACOMP_GAIN		0x0F
  #define DEFAULT_ACOMP_THRESHOLD		(-0x28)
  #define DEFAULT_MUTE			0x01
  #define DEFAULT_POWER_LEVEL		88
  #define DEFAULT_FREQUENCY		8800
  #define DEFAULT_PREEMPHASIS		FMPE_EU
  #define DEFAULT_TUNE_RNL		0xFF
  
  #define to_si4713_device(sd)	container_of(sd, struct si4713_device, sd)
  
  /* frequency domain transformation (using times 10 to avoid floats) */
  #define FREQDEV_UNIT	100000
  #define FREQV4L2_MULTI	625
  #define si4713_to_v4l2(f)	((f * FREQDEV_UNIT) / FREQV4L2_MULTI)
  #define v4l2_to_si4713(f)	((f * FREQV4L2_MULTI) / FREQDEV_UNIT)
  #define FREQ_RANGE_LOW			7600
  #define FREQ_RANGE_HIGH			10800
  
  #define MAX_ARGS 7
  
  #define RDS_BLOCK			8
  #define RDS_BLOCK_CLEAR			0x03
  #define RDS_BLOCK_LOAD			0x04
  #define RDS_RADIOTEXT_2A		0x20
  #define RDS_RADIOTEXT_BLK_SIZE		4
  #define RDS_RADIOTEXT_INDEX_MAX		0x0F
  #define RDS_CARRIAGE_RETURN		0x0D
  
  #define rds_ps_nblocks(len)	((len / RDS_BLOCK) + (len % RDS_BLOCK ? 1 : 0))
  
  #define get_status_bit(p, b, m)	(((p) & (m)) >> (b))
  #define set_bits(p, v, b, m)	(((p) & ~(m)) | ((v) << (b)))
  
  #define ATTACK_TIME_UNIT	500
  
  #define POWER_OFF			0x00
  #define POWER_ON			0x01
  
  #define msb(x)                  ((u8)((u16) x >> 8))
  #define lsb(x)                  ((u8)((u16) x &  0x00FF))
  #define compose_u16(msb, lsb)	(((u16)msb << 8) | lsb)
  #define check_command_failed(status)	(!(status & SI4713_CTS) || \
  					(status & SI4713_ERR))
  /* mute definition */
  #define set_mute(p)	((p & 1) | ((p & 1) << 1));
  
  #ifdef DEBUG
  #define DBG_BUFFER(device, message, buffer, size)			\
  	{								\
  		int i;							\
  		char str[(size)*5];					\
  		for (i = 0; i < size; i++)				\
  			sprintf(str + i * 5, " 0x%02x", buffer[i]);	\
  		v4l2_dbg(2, debug, device, "%s:%s
  ", message, str);	\
  	}
  #else
  #define DBG_BUFFER(device, message, buffer, size)
  #endif
  
  /*
   * Values for limiter release time (sorted by second column)
   *	device	release
   *	value	time (us)
   */
  static long limiter_times[] = {
  	2000,	250,
  	1000,	500,
  	510,	1000,
  	255,	2000,
  	170,	3000,
  	127,	4020,
  	102,	5010,
  	85,	6020,
  	73,	7010,
  	64,	7990,
  	57,	8970,
  	51,	10030,
  	25,	20470,
  	17,	30110,
  	13,	39380,
  	10,	51190,
  	8,	63690,
  	7,	73140,
  	6,	85330,
  	5,	102390,
  };
  
  /*
   * Values for audio compression release time (sorted by second column)
   *	device	release
   *	value	time (us)
   */
  static unsigned long acomp_rtimes[] = {
  	0,	100000,
  	1,	200000,
  	2,	350000,
  	3,	525000,
  	4,	1000000,
  };
  
  /*
   * Values for preemphasis (sorted by second column)
   *	device	preemphasis
   *	value	value (v4l2)
   */
  static unsigned long preemphasis_values[] = {
  	FMPE_DISABLED,	V4L2_PREEMPHASIS_DISABLED,
  	FMPE_EU,	V4L2_PREEMPHASIS_50_uS,
  	FMPE_USA,	V4L2_PREEMPHASIS_75_uS,
  };
  
  static int usecs_to_dev(unsigned long usecs, unsigned long const array[],
  			int size)
  {
  	int i;
  	int rval = -EINVAL;
  
  	for (i = 0; i < size / 2; i++)
  		if (array[(i * 2) + 1] >= usecs) {
  			rval = array[i * 2];
  			break;
  		}
  
  	return rval;
  }
  
  /* si4713_handler: IRQ handler, just complete work */
  static irqreturn_t si4713_handler(int irq, void *dev)
  {
  	struct si4713_device *sdev = dev;
  
  	v4l2_dbg(2, debug, &sdev->sd,
  			"%s: sending signal to completion work.
  ", __func__);
  	complete(&sdev->work);
  
  	return IRQ_HANDLED;
  }
  
  /*
   * si4713_send_command - sends a command to si4713 and waits its response
   * @sdev: si4713_device structure for the device we are communicating
   * @command: command id
   * @args: command arguments we are sending (up to 7)
   * @argn: actual size of @args
   * @response: buffer to place the expected response from the device (up to 15)
   * @respn: actual size of @response
   * @usecs: amount of time to wait before reading the response (in usecs)
   */
  static int si4713_send_command(struct si4713_device *sdev, const u8 command,
  				const u8 args[], const int argn,
  				u8 response[], const int respn, const int usecs)
  {
  	struct i2c_client *client = v4l2_get_subdevdata(&sdev->sd);
  	unsigned long until_jiffies;
  	u8 data1[MAX_ARGS + 1];
  	int err;
  
  	if (!client->adapter)
  		return -ENODEV;
  
  	/* First send the command and its arguments */
  	data1[0] = command;
  	memcpy(data1 + 1, args, argn);
  	DBG_BUFFER(&sdev->sd, "Parameters", data1, argn + 1);
  
  	err = i2c_master_send(client, data1, argn + 1);
  	if (err != argn + 1) {
  		v4l2_err(&sdev->sd, "Error while sending command 0x%02x
  ",
  			command);
  		return err < 0 ? err : -EIO;
  	}
  
  	until_jiffies = jiffies + usecs_to_jiffies(usecs) + 1;
  
  	/* Wait response from interrupt */
  	if (client->irq) {
  		if (!wait_for_completion_timeout(&sdev->work,
  				usecs_to_jiffies(usecs) + 1))
  			v4l2_warn(&sdev->sd,
  				"(%s) Device took too much time to answer.
  ",
  				__func__);
  	}
  
  	do {
  		err = i2c_master_recv(client, response, respn);
  		if (err != respn) {
  			v4l2_err(&sdev->sd,
  				"Error %d while reading response for command 0x%02x
  ",
  				err, command);
  			return err < 0 ? err : -EIO;
  		}
  
  		DBG_BUFFER(&sdev->sd, "Response", response, respn);
  		if (!check_command_failed(response[0]))
  			return 0;
  
  		if (client->irq)
  			return -EBUSY;
  		if (usecs <= 1000)
  			usleep_range(usecs, 1000);
  		else
  			usleep_range(1000, 2000);
  	} while (time_is_after_jiffies(until_jiffies));
  
  	return -EBUSY;
  }
  
  /*
   * si4713_read_property - reads a si4713 property
   * @sdev: si4713_device structure for the device we are communicating
   * @prop: property identification number
   * @pv: property value to be returned on success
   */
  static int si4713_read_property(struct si4713_device *sdev, u16 prop, u32 *pv)
  {
  	int err;
  	u8 val[SI4713_GET_PROP_NRESP];
  	/*
  	 *	.First byte = 0
  	 *	.Second byte = property's MSB
  	 *	.Third byte = property's LSB
  	 */
  	const u8 args[SI4713_GET_PROP_NARGS] = {
  		0x00,
  		msb(prop),
  		lsb(prop),
  	};
  
  	err = si4713_send_command(sdev, SI4713_CMD_GET_PROPERTY,
  				  args, ARRAY_SIZE(args), val,
  				  ARRAY_SIZE(val), DEFAULT_TIMEOUT);
  
  	if (err < 0)
  		return err;
  
  	*pv = compose_u16(val[2], val[3]);
  
  	v4l2_dbg(1, debug, &sdev->sd,
  			"%s: property=0x%02x value=0x%02x status=0x%02x
  ",
  			__func__, prop, *pv, val[0]);
  
  	return err;
  }
  
  /*
   * si4713_write_property - modifies a si4713 property
   * @sdev: si4713_device structure for the device we are communicating
   * @prop: property identification number
   * @val: new value for that property
   */
  static int si4713_write_property(struct si4713_device *sdev, u16 prop, u16 val)
  {
  	int rval;
  	u8 resp[SI4713_SET_PROP_NRESP];
  	/*
  	 *	.First byte = 0
  	 *	.Second byte = property's MSB
  	 *	.Third byte = property's LSB
  	 *	.Fourth byte = value's MSB
  	 *	.Fifth byte = value's LSB
  	 */
  	const u8 args[SI4713_SET_PROP_NARGS] = {
  		0x00,
  		msb(prop),
  		lsb(prop),
  		msb(val),
  		lsb(val),
  	};
  
  	rval = si4713_send_command(sdev, SI4713_CMD_SET_PROPERTY,
  					args, ARRAY_SIZE(args),
  					resp, ARRAY_SIZE(resp),
  					DEFAULT_TIMEOUT);
  
  	if (rval < 0)
  		return rval;
  
  	v4l2_dbg(1, debug, &sdev->sd,
  			"%s: property=0x%02x value=0x%02x status=0x%02x
  ",
  			__func__, prop, val, resp[0]);
  
  	/*
  	 * As there is no command response for SET_PROPERTY,
  	 * wait Tcomp time to finish before proceed, in order
  	 * to have property properly set.
  	 */
  	msleep(TIMEOUT_SET_PROPERTY);
  
  	return rval;
  }
  
  /*
   * si4713_powerup - Powers the device up
   * @sdev: si4713_device structure for the device we are communicating
   */
  static int si4713_powerup(struct si4713_device *sdev)
  {
  	struct i2c_client *client = v4l2_get_subdevdata(&sdev->sd);
  	int err;
  	u8 resp[SI4713_PWUP_NRESP];
  	/*
  	 *	.First byte = Enabled interrupts and boot function
  	 *	.Second byte = Input operation mode
  	 */
  	u8 args[SI4713_PWUP_NARGS] = {
  		SI4713_PWUP_GPO2OEN | SI4713_PWUP_FUNC_TX,
  		SI4713_PWUP_OPMOD_ANALOG,
  	};
  
  	if (sdev->power_state)
  		return 0;
  
  	if (sdev->vdd) {
  		err = regulator_enable(sdev->vdd);
  		if (err) {
  			v4l2_err(&sdev->sd, "Failed to enable vdd: %d
  ", err);
  			return err;
  		}
  	}
  
  	if (sdev->vio) {
  		err = regulator_enable(sdev->vio);
  		if (err) {
  			v4l2_err(&sdev->sd, "Failed to enable vio: %d
  ", err);
  			return err;
  		}
  	}
  
  	if (sdev->gpio_reset) {
  		udelay(50);
  		gpiod_set_value(sdev->gpio_reset, 1);
  	}
  
  	if (client->irq)
  		args[0] |= SI4713_PWUP_CTSIEN;
  
  	err = si4713_send_command(sdev, SI4713_CMD_POWER_UP,
  					args, ARRAY_SIZE(args),
  					resp, ARRAY_SIZE(resp),
  					TIMEOUT_POWER_UP);
  
  	if (!err) {
  		v4l2_dbg(1, debug, &sdev->sd, "Powerup response: 0x%02x
  ",
  				resp[0]);
  		v4l2_dbg(1, debug, &sdev->sd, "Device in power up mode
  ");
  		sdev->power_state = POWER_ON;
  
  		if (client->irq)
  			err = si4713_write_property(sdev, SI4713_GPO_IEN,
  						SI4713_STC_INT | SI4713_CTS);
  		return err;
  	}
  	gpiod_set_value(sdev->gpio_reset, 0);
  
  
  	if (sdev->vdd) {
  		err = regulator_disable(sdev->vdd);
  		if (err)
  			v4l2_err(&sdev->sd, "Failed to disable vdd: %d
  ", err);
  	}
  
  	if (sdev->vio) {
  		err = regulator_disable(sdev->vio);
  		if (err)
  			v4l2_err(&sdev->sd, "Failed to disable vio: %d
  ", err);
  	}
  
  	return err;
  }
  
  /*
   * si4713_powerdown - Powers the device down
   * @sdev: si4713_device structure for the device we are communicating
   */
  static int si4713_powerdown(struct si4713_device *sdev)
  {
  	int err;
  	u8 resp[SI4713_PWDN_NRESP];
  
  	if (!sdev->power_state)
  		return 0;
  
  	err = si4713_send_command(sdev, SI4713_CMD_POWER_DOWN,
  					NULL, 0,
  					resp, ARRAY_SIZE(resp),
  					DEFAULT_TIMEOUT);
  
  	if (!err) {
  		v4l2_dbg(1, debug, &sdev->sd, "Power down response: 0x%02x
  ",
  				resp[0]);
  		v4l2_dbg(1, debug, &sdev->sd, "Device in reset mode
  ");
  		if (sdev->gpio_reset)
  			gpiod_set_value(sdev->gpio_reset, 0);
  
  		if (sdev->vdd) {
  			err = regulator_disable(sdev->vdd);
  			if (err) {
  				v4l2_err(&sdev->sd,
  					"Failed to disable vdd: %d
  ", err);
  			}
  		}
  
  		if (sdev->vio) {
  			err = regulator_disable(sdev->vio);
  			if (err) {
  				v4l2_err(&sdev->sd,
  					"Failed to disable vio: %d
  ", err);
  			}
  		}
  		sdev->power_state = POWER_OFF;
  	}
  
  	return err;
  }
  
  /*
   * si4713_checkrev - Checks if we are treating a device with the correct rev.
   * @sdev: si4713_device structure for the device we are communicating
   */
  static int si4713_checkrev(struct si4713_device *sdev)
  {
  	struct i2c_client *client = v4l2_get_subdevdata(&sdev->sd);
  	int rval;
  	u8 resp[SI4713_GETREV_NRESP];
  
  	rval = si4713_send_command(sdev, SI4713_CMD_GET_REV,
  					NULL, 0,
  					resp, ARRAY_SIZE(resp),
  					DEFAULT_TIMEOUT);
  
  	if (rval < 0)
  		return rval;
  
  	if (resp[1] == SI4713_PRODUCT_NUMBER) {
  		v4l2_info(&sdev->sd, "chip found @ 0x%02x (%s)
  ",
  				client->addr << 1, client->adapter->name);
  	} else {
  		v4l2_err(&sdev->sd, "Invalid product number 0x%X
  ", resp[1]);
  		rval = -EINVAL;
  	}
  	return rval;
  }
  
  /*
   * si4713_wait_stc - Waits STC interrupt and clears status bits. Useful
   *		     for TX_TUNE_POWER, TX_TUNE_FREQ and TX_TUNE_MEAS
   * @sdev: si4713_device structure for the device we are communicating
   * @usecs: timeout to wait for STC interrupt signal
   */
  static int si4713_wait_stc(struct si4713_device *sdev, const int usecs)
  {
  	struct i2c_client *client = v4l2_get_subdevdata(&sdev->sd);
  	u8 resp[SI4713_GET_STATUS_NRESP];
  	unsigned long start_jiffies = jiffies;
  	int err;
  
  	if (client->irq &&
  	    !wait_for_completion_timeout(&sdev->work, usecs_to_jiffies(usecs) + 1))
  		v4l2_warn(&sdev->sd,
  			"(%s) Device took too much time to answer.
  ", __func__);
  
  	for (;;) {
  		/* Clear status bits */
  		err = si4713_send_command(sdev, SI4713_CMD_GET_INT_STATUS,
  				NULL, 0,
  				resp, ARRAY_SIZE(resp),
  				DEFAULT_TIMEOUT);
  		/* The USB device returns errors when it waits for the
  		 * STC bit to be set. Hence polling */
  		if (err >= 0) {
  			v4l2_dbg(1, debug, &sdev->sd,
  				"%s: status bits: 0x%02x
  ", __func__, resp[0]);
  
  			if (resp[0] & SI4713_STC_INT)
  				return 0;
  		}
  		if (jiffies_to_usecs(jiffies - start_jiffies) > usecs)
  			return err < 0 ? err : -EIO;
  		/* We sleep here for 3-4 ms in order to avoid flooding the device
  		 * with USB requests. The si4713 USB driver was developed
  		 * by reverse engineering the Windows USB driver. The windows
  		 * driver also has a ~2.5 ms delay between responses. */
  		usleep_range(3000, 4000);
  	}
  }
  
  /*
   * si4713_tx_tune_freq - Sets the state of the RF carrier and sets the tuning
   *			frequency between 76 and 108 MHz in 10 kHz units and
   *			steps of 50 kHz.
   * @sdev: si4713_device structure for the device we are communicating
   * @frequency: desired frequency (76 - 108 MHz, unit 10 KHz, step 50 kHz)
   */
  static int si4713_tx_tune_freq(struct si4713_device *sdev, u16 frequency)
  {
  	int err;
  	u8 val[SI4713_TXFREQ_NRESP];
  	/*
  	 *	.First byte = 0
  	 *	.Second byte = frequency's MSB
  	 *	.Third byte = frequency's LSB
  	 */
  	const u8 args[SI4713_TXFREQ_NARGS] = {
  		0x00,
  		msb(frequency),
  		lsb(frequency),
  	};
  
  	err = si4713_send_command(sdev, SI4713_CMD_TX_TUNE_FREQ,
  				  args, ARRAY_SIZE(args), val,
  				  ARRAY_SIZE(val), DEFAULT_TIMEOUT);
  
  	if (err < 0)
  		return err;
  
  	v4l2_dbg(1, debug, &sdev->sd,
  			"%s: frequency=0x%02x status=0x%02x
  ", __func__,
  			frequency, val[0]);
  
  	err = si4713_wait_stc(sdev, TIMEOUT_TX_TUNE);
  	if (err < 0)
  		return err;
  
  	return compose_u16(args[1], args[2]);
  }
  
  /*
   * si4713_tx_tune_power - Sets the RF voltage level between 88 and 120 dBuV in
   *			1 dB units. A value of 0x00 indicates off. The command
   *			also sets the antenna tuning capacitance. A value of 0
   *			indicates autotuning, and a value of 1 - 191 indicates
   *			a manual override, which results in a tuning
   *			capacitance of 0.25 pF x @antcap.
   * @sdev: si4713_device structure for the device we are communicating
   * @power: tuning power (88 - 120 dBuV, unit/step 1 dB)
   * @antcap: value of antenna tuning capacitor (0 - 191)
   */
  static int si4713_tx_tune_power(struct si4713_device *sdev, u8 power,
  				u8 antcap)
  {
  	int err;
  	u8 val[SI4713_TXPWR_NRESP];
  	/*
  	 *	.First byte = 0
  	 *	.Second byte = 0
  	 *	.Third byte = power
  	 *	.Fourth byte = antcap
  	 */
  	u8 args[SI4713_TXPWR_NARGS] = {
  		0x00,
  		0x00,
  		power,
  		antcap,
  	};
  
  	/* Map power values 1-87 to MIN_POWER (88) */
  	if (power > 0 && power < SI4713_MIN_POWER)
  		args[2] = power = SI4713_MIN_POWER;
  
  	err = si4713_send_command(sdev, SI4713_CMD_TX_TUNE_POWER,
  				  args, ARRAY_SIZE(args), val,
  				  ARRAY_SIZE(val), DEFAULT_TIMEOUT);
  
  	if (err < 0)
  		return err;
  
  	v4l2_dbg(1, debug, &sdev->sd,
  			"%s: power=0x%02x antcap=0x%02x status=0x%02x
  ",
  			__func__, power, antcap, val[0]);
  
  	return si4713_wait_stc(sdev, TIMEOUT_TX_TUNE_POWER);
  }
  
  /*
   * si4713_tx_tune_measure - Enters receive mode and measures the received noise
   *			level in units of dBuV on the selected frequency.
   *			The Frequency must be between 76 and 108 MHz in 10 kHz
   *			units and steps of 50 kHz. The command also sets the
   *			antenna	tuning capacitance. A value of 0 means
   *			autotuning, and a value of 1 to 191 indicates manual
   *			override.
   * @sdev: si4713_device structure for the device we are communicating
   * @frequency: desired frequency (76 - 108 MHz, unit 10 KHz, step 50 kHz)
   * @antcap: value of antenna tuning capacitor (0 - 191)
   */
  static int si4713_tx_tune_measure(struct si4713_device *sdev, u16 frequency,
  					u8 antcap)
  {
  	int err;
  	u8 val[SI4713_TXMEA_NRESP];
  	/*
  	 *	.First byte = 0
  	 *	.Second byte = frequency's MSB
  	 *	.Third byte = frequency's LSB
  	 *	.Fourth byte = antcap
  	 */
  	const u8 args[SI4713_TXMEA_NARGS] = {
  		0x00,
  		msb(frequency),
  		lsb(frequency),
  		antcap,
  	};
  
  	sdev->tune_rnl = DEFAULT_TUNE_RNL;
  
  	if (antcap > SI4713_MAX_ANTCAP)
  		return -EDOM;
  
  	err = si4713_send_command(sdev, SI4713_CMD_TX_TUNE_MEASURE,
  				  args, ARRAY_SIZE(args), val,
  				  ARRAY_SIZE(val), DEFAULT_TIMEOUT);
  
  	if (err < 0)
  		return err;
  
  	v4l2_dbg(1, debug, &sdev->sd,
  			"%s: frequency=0x%02x antcap=0x%02x status=0x%02x
  ",
  			__func__, frequency, antcap, val[0]);
  
  	return si4713_wait_stc(sdev, TIMEOUT_TX_TUNE);
  }
  
  /*
   * si4713_tx_tune_status- Returns the status of the tx_tune_freq, tx_tune_mea or
   *			tx_tune_power commands. This command return the current
   *			frequency, output voltage in dBuV, the antenna tunning
   *			capacitance value and the received noise level. The
   *			command also clears the stcint interrupt bit when the
   *			first bit of its arguments is high.
   * @sdev: si4713_device structure for the device we are communicating
   * @intack: 0x01 to clear the seek/tune complete interrupt status indicator.
   * @frequency: returned frequency
   * @power: returned power
   * @antcap: returned antenna capacitance
   * @noise: returned noise level
   */
  static int si4713_tx_tune_status(struct si4713_device *sdev, u8 intack,
  					u16 *frequency,	u8 *power,
  					u8 *antcap, u8 *noise)
  {
  	int err;
  	u8 val[SI4713_TXSTATUS_NRESP];
  	/*
  	 *	.First byte = intack bit
  	 */
  	const u8 args[SI4713_TXSTATUS_NARGS] = {
  		intack & SI4713_INTACK_MASK,
  	};
  
  	err = si4713_send_command(sdev, SI4713_CMD_TX_TUNE_STATUS,
  				  args, ARRAY_SIZE(args), val,
  				  ARRAY_SIZE(val), DEFAULT_TIMEOUT);
  
  	if (!err) {
  		v4l2_dbg(1, debug, &sdev->sd,
  			"%s: status=0x%02x
  ", __func__, val[0]);
  		*frequency = compose_u16(val[2], val[3]);
  		sdev->frequency = *frequency;
  		*power = val[5];
  		*antcap = val[6];
  		*noise = val[7];
  		v4l2_dbg(1, debug, &sdev->sd, "%s: response: %d x 10 kHz "
  				"(power %d, antcap %d, rnl %d)
  ", __func__,
  				*frequency, *power, *antcap, *noise);
  	}
  
  	return err;
  }
  
  /*
   * si4713_tx_rds_buff - Loads the RDS group buffer FIFO or circular buffer.
   * @sdev: si4713_device structure for the device we are communicating
   * @mode: the buffer operation mode.
   * @rdsb: RDS Block B
   * @rdsc: RDS Block C
   * @rdsd: RDS Block D
   * @cbleft: returns the number of available circular buffer blocks minus the
   *          number of used circular buffer blocks.
   */
  static int si4713_tx_rds_buff(struct si4713_device *sdev, u8 mode, u16 rdsb,
  				u16 rdsc, u16 rdsd, s8 *cbleft)
  {
  	int err;
  	u8 val[SI4713_RDSBUFF_NRESP];
  
  	const u8 args[SI4713_RDSBUFF_NARGS] = {
  		mode & SI4713_RDSBUFF_MODE_MASK,
  		msb(rdsb),
  		lsb(rdsb),
  		msb(rdsc),
  		lsb(rdsc),
  		msb(rdsd),
  		lsb(rdsd),
  	};
  
  	err = si4713_send_command(sdev, SI4713_CMD_TX_RDS_BUFF,
  				  args, ARRAY_SIZE(args), val,
  				  ARRAY_SIZE(val), DEFAULT_TIMEOUT);
  
  	if (!err) {
  		v4l2_dbg(1, debug, &sdev->sd,
  			"%s: status=0x%02x
  ", __func__, val[0]);
  		*cbleft = (s8)val[2] - val[3];
  		v4l2_dbg(1, debug, &sdev->sd, "%s: response: interrupts"
  				" 0x%02x cb avail: %d cb used %d fifo avail"
  				" %d fifo used %d
  ", __func__, val[1],
  				val[2], val[3], val[4], val[5]);
  	}
  
  	return err;
  }
  
  /*
   * si4713_tx_rds_ps - Loads the program service buffer.
   * @sdev: si4713_device structure for the device we are communicating
   * @psid: program service id to be loaded.
   * @pschar: assumed 4 size char array to be loaded into the program service
   */
  static int si4713_tx_rds_ps(struct si4713_device *sdev, u8 psid,
  				unsigned char *pschar)
  {
  	int err;
  	u8 val[SI4713_RDSPS_NRESP];
  
  	const u8 args[SI4713_RDSPS_NARGS] = {
  		psid & SI4713_RDSPS_PSID_MASK,
  		pschar[0],
  		pschar[1],
  		pschar[2],
  		pschar[3],
  	};
  
  	err = si4713_send_command(sdev, SI4713_CMD_TX_RDS_PS,
  				  args, ARRAY_SIZE(args), val,
  				  ARRAY_SIZE(val), DEFAULT_TIMEOUT);
  
  	if (err < 0)
  		return err;
  
  	v4l2_dbg(1, debug, &sdev->sd, "%s: status=0x%02x
  ", __func__, val[0]);
  
  	return err;
  }
  
  static int si4713_set_power_state(struct si4713_device *sdev, u8 value)
  {
  	if (value)
  		return si4713_powerup(sdev);
  	return si4713_powerdown(sdev);
  }
  
  static int si4713_set_mute(struct si4713_device *sdev, u16 mute)
  {
  	int rval = 0;
  
  	mute = set_mute(mute);
  
  	if (sdev->power_state)
  		rval = si4713_write_property(sdev,
  				SI4713_TX_LINE_INPUT_MUTE, mute);
  
  	return rval;
  }
  
  static int si4713_set_rds_ps_name(struct si4713_device *sdev, char *ps_name)
  {
  	int rval = 0, i;
  	u8 len = 0;
  
  	/* We want to clear the whole thing */
  	if (!strlen(ps_name))
  		memset(ps_name, 0, MAX_RDS_PS_NAME + 1);
  
  	if (sdev->power_state) {
  		/* Write the new ps name and clear the padding */
  		for (i = 0; i < MAX_RDS_PS_NAME; i += (RDS_BLOCK / 2)) {
  			rval = si4713_tx_rds_ps(sdev, (i / (RDS_BLOCK / 2)),
  						ps_name + i);
  			if (rval < 0)
  				return rval;
  		}
  
  		/* Setup the size to be sent */
  		if (strlen(ps_name))
  			len = strlen(ps_name) - 1;
  		else
  			len = 1;
  
  		rval = si4713_write_property(sdev,
  				SI4713_TX_RDS_PS_MESSAGE_COUNT,
  				rds_ps_nblocks(len));
  		if (rval < 0)
  			return rval;
  
  		rval = si4713_write_property(sdev,
  				SI4713_TX_RDS_PS_REPEAT_COUNT,
  				DEFAULT_RDS_PS_REPEAT_COUNT * 2);
  		if (rval < 0)
  			return rval;
  	}
  
  	return rval;
  }
  
  static int si4713_set_rds_radio_text(struct si4713_device *sdev, const char *rt)
  {
  	static const char cr[RDS_RADIOTEXT_BLK_SIZE] = { RDS_CARRIAGE_RETURN, 0 };
  	int rval = 0, i;
  	u16 t_index = 0;
  	u8 b_index = 0, cr_inserted = 0;
  	s8 left;
  
  	if (!sdev->power_state)
  		return rval;
  
  	rval = si4713_tx_rds_buff(sdev, RDS_BLOCK_CLEAR, 0, 0, 0, &left);
  	if (rval < 0)
  		return rval;
  
  	if (!strlen(rt))
  		return rval;
  
  	do {
  		/* RDS spec says that if the last block isn't used,
  		 * then apply a carriage return
  		 */
  		if (t_index < (RDS_RADIOTEXT_INDEX_MAX * RDS_RADIOTEXT_BLK_SIZE)) {
  			for (i = 0; i < RDS_RADIOTEXT_BLK_SIZE; i++) {
  				if (!rt[t_index + i] ||
  				    rt[t_index + i] == RDS_CARRIAGE_RETURN) {
  					rt = cr;
  					cr_inserted = 1;
  					break;
  				}
  			}
  		}
  
  		rval = si4713_tx_rds_buff(sdev, RDS_BLOCK_LOAD,
  				compose_u16(RDS_RADIOTEXT_2A, b_index++),
  				compose_u16(rt[t_index], rt[t_index + 1]),
  				compose_u16(rt[t_index + 2], rt[t_index + 3]),
  				&left);
  		if (rval < 0)
  			return rval;
  
  		t_index += RDS_RADIOTEXT_BLK_SIZE;
  
  		if (cr_inserted)
  			break;
  	} while (left > 0);
  
  	return rval;
  }
  
  /*
   * si4713_update_tune_status - update properties from tx_tune_status
   * command. Must be called with sdev->mutex held.
   * @sdev: si4713_device structure for the device we are communicating
   */
  static int si4713_update_tune_status(struct si4713_device *sdev)
  {
  	int rval;
  	u16 f = 0;
  	u8 p = 0, a = 0, n = 0;
  
  	rval = si4713_tx_tune_status(sdev, 0x00, &f, &p, &a, &n);
  
  	if (rval < 0)
  		goto exit;
  
  /*	TODO: check that power_level and antenna_capacitor really are not
  	changed by the hardware. If they are, then these controls should become
  	volatiles.
  	sdev->power_level = p;
  	sdev->antenna_capacitor = a;*/
  	sdev->tune_rnl = n;
  
  exit:
  	return rval;
  }
  
  static int si4713_choose_econtrol_action(struct si4713_device *sdev, u32 id,
  		s32 *bit, s32 *mask, u16 *property, int *mul,
  		unsigned long **table, int *size)
  {
  	s32 rval = 0;
  
  	switch (id) {
  	/* FM_TX class controls */
  	case V4L2_CID_RDS_TX_PI:
  		*property = SI4713_TX_RDS_PI;
  		*mul = 1;
  		break;
  	case V4L2_CID_AUDIO_COMPRESSION_THRESHOLD:
  		*property = SI4713_TX_ACOMP_THRESHOLD;
  		*mul = 1;
  		break;
  	case V4L2_CID_AUDIO_COMPRESSION_GAIN:
  		*property = SI4713_TX_ACOMP_GAIN;
  		*mul = 1;
  		break;
  	case V4L2_CID_PILOT_TONE_FREQUENCY:
  		*property = SI4713_TX_PILOT_FREQUENCY;
  		*mul = 1;
  		break;
  	case V4L2_CID_AUDIO_COMPRESSION_ATTACK_TIME:
  		*property = SI4713_TX_ACOMP_ATTACK_TIME;
  		*mul = ATTACK_TIME_UNIT;
  		break;
  	case V4L2_CID_PILOT_TONE_DEVIATION:
  		*property = SI4713_TX_PILOT_DEVIATION;
  		*mul = 10;
  		break;
  	case V4L2_CID_AUDIO_LIMITER_DEVIATION:
  		*property = SI4713_TX_AUDIO_DEVIATION;
  		*mul = 10;
  		break;
  	case V4L2_CID_RDS_TX_DEVIATION:
  		*property = SI4713_TX_RDS_DEVIATION;
  		*mul = 1;
  		break;
  
  	case V4L2_CID_RDS_TX_PTY:
  		*property = SI4713_TX_RDS_PS_MISC;
  		*bit = 5;
  		*mask = 0x1F << 5;
  		break;
  	case V4L2_CID_RDS_TX_DYNAMIC_PTY:
  		*property = SI4713_TX_RDS_PS_MISC;
  		*bit = 15;
  		*mask = 1 << 15;
  		break;
  	case V4L2_CID_RDS_TX_COMPRESSED:
  		*property = SI4713_TX_RDS_PS_MISC;
  		*bit = 14;
  		*mask = 1 << 14;
  		break;
  	case V4L2_CID_RDS_TX_ARTIFICIAL_HEAD:
  		*property = SI4713_TX_RDS_PS_MISC;
  		*bit = 13;
  		*mask = 1 << 13;
  		break;
  	case V4L2_CID_RDS_TX_MONO_STEREO:
  		*property = SI4713_TX_RDS_PS_MISC;
  		*bit = 12;
  		*mask = 1 << 12;
  		break;
  	case V4L2_CID_RDS_TX_TRAFFIC_PROGRAM:
  		*property = SI4713_TX_RDS_PS_MISC;
  		*bit = 10;
  		*mask = 1 << 10;
  		break;
  	case V4L2_CID_RDS_TX_TRAFFIC_ANNOUNCEMENT:
  		*property = SI4713_TX_RDS_PS_MISC;
  		*bit = 4;
  		*mask = 1 << 4;
  		break;
  	case V4L2_CID_RDS_TX_MUSIC_SPEECH:
  		*property = SI4713_TX_RDS_PS_MISC;
  		*bit = 3;
  		*mask = 1 << 3;
  		break;
  	case V4L2_CID_AUDIO_LIMITER_ENABLED:
  		*property = SI4713_TX_ACOMP_ENABLE;
  		*bit = 1;
  		*mask = 1 << 1;
  		break;
  	case V4L2_CID_AUDIO_COMPRESSION_ENABLED:
  		*property = SI4713_TX_ACOMP_ENABLE;
  		*bit = 0;
  		*mask = 1 << 0;
  		break;
  	case V4L2_CID_PILOT_TONE_ENABLED:
  		*property = SI4713_TX_COMPONENT_ENABLE;
  		*bit = 0;
  		*mask = 1 << 0;
  		break;
  
  	case V4L2_CID_AUDIO_LIMITER_RELEASE_TIME:
  		*property = SI4713_TX_LIMITER_RELEASE_TIME;
  		*table = limiter_times;
  		*size = ARRAY_SIZE(limiter_times);
  		break;
  	case V4L2_CID_AUDIO_COMPRESSION_RELEASE_TIME:
  		*property = SI4713_TX_ACOMP_RELEASE_TIME;
  		*table = acomp_rtimes;
  		*size = ARRAY_SIZE(acomp_rtimes);
  		break;
  	case V4L2_CID_TUNE_PREEMPHASIS:
  		*property = SI4713_TX_PREEMPHASIS;
  		*table = preemphasis_values;
  		*size = ARRAY_SIZE(preemphasis_values);
  		break;
  
  	default:
  		rval = -EINVAL;
  		break;
  	}
  
  	return rval;
  }
  
  static int si4713_s_frequency(struct v4l2_subdev *sd, const struct v4l2_frequency *f);
  static int si4713_s_modulator(struct v4l2_subdev *sd, const struct v4l2_modulator *);
  /*
   * si4713_setup - Sets the device up with current configuration.
   * @sdev: si4713_device structure for the device we are communicating
   */
  static int si4713_setup(struct si4713_device *sdev)
  {
  	struct v4l2_frequency f;
  	struct v4l2_modulator vm;
  	int rval;
  
  	/* Device procedure needs to set frequency first */
  	f.tuner = 0;
  	f.frequency = sdev->frequency ? sdev->frequency : DEFAULT_FREQUENCY;
  	f.frequency = si4713_to_v4l2(f.frequency);
  	rval = si4713_s_frequency(&sdev->sd, &f);
  
  	vm.index = 0;
  	if (sdev->stereo)
  		vm.txsubchans = V4L2_TUNER_SUB_STEREO;
  	else
  		vm.txsubchans = V4L2_TUNER_SUB_MONO;
  	if (sdev->rds_enabled)
  		vm.txsubchans |= V4L2_TUNER_SUB_RDS;
  	si4713_s_modulator(&sdev->sd, &vm);
  
  	return rval;
  }
  
  /*
   * si4713_initialize - Sets the device up with default configuration.
   * @sdev: si4713_device structure for the device we are communicating
   */
  static int si4713_initialize(struct si4713_device *sdev)
  {
  	int rval;
  
  	rval = si4713_set_power_state(sdev, POWER_ON);
  	if (rval < 0)
  		return rval;
  
  	rval = si4713_checkrev(sdev);
  	if (rval < 0)
  		return rval;
  
  	rval = si4713_set_power_state(sdev, POWER_OFF);
  	if (rval < 0)
  		return rval;
  
  	sdev->frequency = DEFAULT_FREQUENCY;
  	sdev->stereo = 1;
  	sdev->tune_rnl = DEFAULT_TUNE_RNL;
  	return 0;
  }
  
  /* si4713_s_ctrl - set the value of a control */
  static int si4713_s_ctrl(struct v4l2_ctrl *ctrl)
  {
  	struct si4713_device *sdev =
  		container_of(ctrl->handler, struct si4713_device, ctrl_handler);
  	u32 val = 0;
  	s32 bit = 0, mask = 0;
  	u16 property = 0;
  	int mul = 0;
  	unsigned long *table = NULL;
  	int size = 0;
  	bool force = false;
  	int c;
  	int ret = 0;
  
  	if (ctrl->id != V4L2_CID_AUDIO_MUTE)
  		return -EINVAL;
  	if (ctrl->is_new) {
  		if (ctrl->val) {
  			ret = si4713_set_mute(sdev, ctrl->val);
  			if (!ret)
  				ret = si4713_set_power_state(sdev, POWER_DOWN);
  			return ret;
  		}
  		ret = si4713_set_power_state(sdev, POWER_UP);
  		if (!ret)
  			ret = si4713_set_mute(sdev, ctrl->val);
  		if (!ret)
  			ret = si4713_setup(sdev);
  		if (ret)
  			return ret;
  		force = true;
  	}
  
  	if (!sdev->power_state)
  		return 0;
  
  	for (c = 1; !ret && c < ctrl->ncontrols; c++) {
  		ctrl = ctrl->cluster[c];
  
  		if (!force && !ctrl->is_new)
  			continue;
  
  		switch (ctrl->id) {
  		case V4L2_CID_RDS_TX_PS_NAME:
  			ret = si4713_set_rds_ps_name(sdev, ctrl->p_new.p_char);
  			break;
  
  		case V4L2_CID_RDS_TX_RADIO_TEXT:
  			ret = si4713_set_rds_radio_text(sdev, ctrl->p_new.p_char);
  			break;
  
  		case V4L2_CID_TUNE_ANTENNA_CAPACITOR:
  			/* don't handle this control if we force setting all
  			 * controls since in that case it will be handled by
  			 * V4L2_CID_TUNE_POWER_LEVEL. */
  			if (force)
  				break;
  			/* fall through */
  		case V4L2_CID_TUNE_POWER_LEVEL:
  			ret = si4713_tx_tune_power(sdev,
  				sdev->tune_pwr_level->val, sdev->tune_ant_cap->val);
  			if (!ret) {
  				/* Make sure we don't set this twice */
  				sdev->tune_ant_cap->is_new = false;
  				sdev->tune_pwr_level->is_new = false;
  			}
  			break;
  
  		case V4L2_CID_RDS_TX_ALT_FREQS_ENABLE:
  		case V4L2_CID_RDS_TX_ALT_FREQS:
  			if (sdev->rds_alt_freqs_enable->val) {
  				val = sdev->rds_alt_freqs->p_new.p_u32[0];
  				val = val / 100 - 876 + 0xe101;
  			} else {
  				val = 0xe0e0;
  			}
  			ret = si4713_write_property(sdev, SI4713_TX_RDS_PS_AF, val);
  			break;
  
  		default:
  			ret = si4713_choose_econtrol_action(sdev, ctrl->id, &bit,
  					&mask, &property, &mul, &table, &size);
  			if (ret < 0)
  				break;
  
  			val = ctrl->val;
  			if (mul) {
  				val = val / mul;
  			} else if (table) {
  				ret = usecs_to_dev(val, table, size);
  				if (ret < 0)
  					break;
  				val = ret;
  				ret = 0;
  			}
  
  			if (mask) {
  				ret = si4713_read_property(sdev, property, &val);
  				if (ret < 0)
  					break;
  				val = set_bits(val, ctrl->val, bit, mask);
  			}
  
  			ret = si4713_write_property(sdev, property, val);
  			if (ret < 0)
  				break;
  			if (mask)
  				val = ctrl->val;
  			break;
  		}
  	}
  
  	return ret;
  }
  
  /* si4713_ioctl - deal with private ioctls (only rnl for now) */
  static long si4713_ioctl(struct v4l2_subdev *sd, unsigned int cmd, void *arg)
  {
  	struct si4713_device *sdev = to_si4713_device(sd);
  	struct si4713_rnl *rnl = arg;
  	u16 frequency;
  	int rval = 0;
  
  	if (!arg)
  		return -EINVAL;
  
  	switch (cmd) {
  	case SI4713_IOC_MEASURE_RNL:
  		frequency = v4l2_to_si4713(rnl->frequency);
  
  		if (sdev->power_state) {
  			/* Set desired measurement frequency */
  			rval = si4713_tx_tune_measure(sdev, frequency, 0);
  			if (rval < 0)
  				return rval;
  			/* get results from tune status */
  			rval = si4713_update_tune_status(sdev);
  			if (rval < 0)
  				return rval;
  		}
  		rnl->rnl = sdev->tune_rnl;
  		break;
  
  	default:
  		/* nothing */
  		rval = -ENOIOCTLCMD;
  	}
  
  	return rval;
  }
  
  /* si4713_g_modulator - get modulator attributes */
  static int si4713_g_modulator(struct v4l2_subdev *sd, struct v4l2_modulator *vm)
  {
  	struct si4713_device *sdev = to_si4713_device(sd);
  	int rval = 0;
  
  	if (!sdev)
  		return -ENODEV;
  
  	if (vm->index > 0)
  		return -EINVAL;
  
  	strncpy(vm->name, "FM Modulator", 32);
  	vm->capability = V4L2_TUNER_CAP_STEREO | V4L2_TUNER_CAP_LOW |
  		V4L2_TUNER_CAP_RDS | V4L2_TUNER_CAP_RDS_CONTROLS;
  
  	/* Report current frequency range limits */
  	vm->rangelow = si4713_to_v4l2(FREQ_RANGE_LOW);
  	vm->rangehigh = si4713_to_v4l2(FREQ_RANGE_HIGH);
  
  	if (sdev->power_state) {
  		u32 comp_en = 0;
  
  		rval = si4713_read_property(sdev, SI4713_TX_COMPONENT_ENABLE,
  						&comp_en);
  		if (rval < 0)
  			return rval;
  
  		sdev->stereo = get_status_bit(comp_en, 1, 1 << 1);
  	}
  
  	/* Report current audio mode: mono or stereo */
  	if (sdev->stereo)
  		vm->txsubchans = V4L2_TUNER_SUB_STEREO;
  	else
  		vm->txsubchans = V4L2_TUNER_SUB_MONO;
  
  	/* Report rds feature status */
  	if (sdev->rds_enabled)
  		vm->txsubchans |= V4L2_TUNER_SUB_RDS;
  	else
  		vm->txsubchans &= ~V4L2_TUNER_SUB_RDS;
  
  	return rval;
  }
  
  /* si4713_s_modulator - set modulator attributes */
  static int si4713_s_modulator(struct v4l2_subdev *sd, const struct v4l2_modulator *vm)
  {
  	struct si4713_device *sdev = to_si4713_device(sd);
  	int rval = 0;
  	u16 stereo, rds;
  	u32 p;
  
  	if (!sdev)
  		return -ENODEV;
  
  	if (vm->index > 0)
  		return -EINVAL;
  
  	/* Set audio mode: mono or stereo */
  	if (vm->txsubchans & V4L2_TUNER_SUB_STEREO)
  		stereo = 1;
  	else if (vm->txsubchans & V4L2_TUNER_SUB_MONO)
  		stereo = 0;
  	else
  		return -EINVAL;
  
  	rds = !!(vm->txsubchans & V4L2_TUNER_SUB_RDS);
  
  	if (sdev->power_state) {
  		rval = si4713_read_property(sdev,
  						SI4713_TX_COMPONENT_ENABLE, &p);
  		if (rval < 0)
  			return rval;
  
  		p = set_bits(p, stereo, 1, 1 << 1);
  		p = set_bits(p, rds, 2, 1 << 2);
  
  		rval = si4713_write_property(sdev,
  						SI4713_TX_COMPONENT_ENABLE, p);
  		if (rval < 0)
  			return rval;
  	}
  
  	sdev->stereo = stereo;
  	sdev->rds_enabled = rds;
  
  	return rval;
  }
  
  /* si4713_g_frequency - get tuner or modulator radio frequency */
  static int si4713_g_frequency(struct v4l2_subdev *sd, struct v4l2_frequency *f)
  {
  	struct si4713_device *sdev = to_si4713_device(sd);
  	int rval = 0;
  
  	if (f->tuner)
  		return -EINVAL;
  
  	if (sdev->power_state) {
  		u16 freq;
  		u8 p, a, n;
  
  		rval = si4713_tx_tune_status(sdev, 0x00, &freq, &p, &a, &n);
  		if (rval < 0)
  			return rval;
  
  		sdev->frequency = freq;
  	}
  
  	f->frequency = si4713_to_v4l2(sdev->frequency);
  
  	return rval;
  }
  
  /* si4713_s_frequency - set tuner or modulator radio frequency */
  static int si4713_s_frequency(struct v4l2_subdev *sd, const struct v4l2_frequency *f)
  {
  	struct si4713_device *sdev = to_si4713_device(sd);
  	int rval = 0;
  	u16 frequency = v4l2_to_si4713(f->frequency);
  
  	if (f->tuner)
  		return -EINVAL;
  
  	/* Check frequency range */
  	frequency = clamp_t(u16, frequency, FREQ_RANGE_LOW, FREQ_RANGE_HIGH);
  
  	if (sdev->power_state) {
  		rval = si4713_tx_tune_freq(sdev, frequency);
  		if (rval < 0)
  			return rval;
  		frequency = rval;
  		rval = 0;
  	}
  	sdev->frequency = frequency;
  
  	return rval;
  }
  
  static const struct v4l2_ctrl_ops si4713_ctrl_ops = {
  	.s_ctrl = si4713_s_ctrl,
  };
  
  static const struct v4l2_subdev_core_ops si4713_subdev_core_ops = {
  	.ioctl		= si4713_ioctl,
  };
  
  static const struct v4l2_subdev_tuner_ops si4713_subdev_tuner_ops = {
  	.g_frequency	= si4713_g_frequency,
  	.s_frequency	= si4713_s_frequency,
  	.g_modulator	= si4713_g_modulator,
  	.s_modulator	= si4713_s_modulator,
  };
  
  static const struct v4l2_subdev_ops si4713_subdev_ops = {
  	.core		= &si4713_subdev_core_ops,
  	.tuner		= &si4713_subdev_tuner_ops,
  };
  
  static const struct v4l2_ctrl_config si4713_alt_freqs_ctrl = {
  	.id = V4L2_CID_RDS_TX_ALT_FREQS,
  	.type = V4L2_CTRL_TYPE_U32,
  	.min = 87600,
  	.max = 107900,
  	.step = 100,
  	.def = 87600,
  	.dims = { 1 },
  	.elem_size = sizeof(u32),
  };
  
  /*
   * I2C driver interface
   */
  /* si4713_probe - probe for the device */
  static int si4713_probe(struct i2c_client *client,
  					const struct i2c_device_id *id)
  {
  	struct si4713_device *sdev;
  	struct v4l2_ctrl_handler *hdl;
  	struct si4713_platform_data *pdata = client->dev.platform_data;
  	struct device_node *np = client->dev.of_node;
  	struct radio_si4713_platform_data si4713_pdev_pdata;
  	struct platform_device *si4713_pdev;
  	int rval;
  
  	sdev = devm_kzalloc(&client->dev, sizeof(*sdev), GFP_KERNEL);
  	if (!sdev) {
  		dev_err(&client->dev, "Failed to alloc video device.
  ");
  		rval = -ENOMEM;
  		goto exit;
  	}
  
  	sdev->gpio_reset = devm_gpiod_get_optional(&client->dev, "reset",
  						   GPIOD_OUT_LOW);
  	if (IS_ERR(sdev->gpio_reset)) {
  		rval = PTR_ERR(sdev->gpio_reset);
  		dev_err(&client->dev, "Failed to request gpio: %d
  ", rval);
  		goto exit;
  	}
  
  	sdev->vdd = devm_regulator_get_optional(&client->dev, "vdd");
  	if (IS_ERR(sdev->vdd)) {
  		rval = PTR_ERR(sdev->vdd);
  		if (rval == -EPROBE_DEFER)
  			goto exit;
  
  		dev_dbg(&client->dev, "no vdd regulator found: %d
  ", rval);
  		sdev->vdd = NULL;
  	}
  
  	sdev->vio = devm_regulator_get_optional(&client->dev, "vio");
  	if (IS_ERR(sdev->vio)) {
  		rval = PTR_ERR(sdev->vio);
  		if (rval == -EPROBE_DEFER)
  			goto exit;
  
  		dev_dbg(&client->dev, "no vio regulator found: %d
  ", rval);
  		sdev->vio = NULL;
  	}
  
  	v4l2_i2c_subdev_init(&sdev->sd, client, &si4713_subdev_ops);
  
  	init_completion(&sdev->work);
  
  	hdl = &sdev->ctrl_handler;
  	v4l2_ctrl_handler_init(hdl, 20);
  	sdev->mute = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_AUDIO_MUTE, 0, 1, 1, DEFAULT_MUTE);
  
  	sdev->rds_pi = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_RDS_TX_PI, 0, 0xffff, 1, DEFAULT_RDS_PI);
  	sdev->rds_pty = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_RDS_TX_PTY, 0, 31, 1, DEFAULT_RDS_PTY);
  	sdev->rds_compressed = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_RDS_TX_COMPRESSED, 0, 1, 1, 0);
  	sdev->rds_art_head = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_RDS_TX_ARTIFICIAL_HEAD, 0, 1, 1, 0);
  	sdev->rds_stereo = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_RDS_TX_MONO_STEREO, 0, 1, 1, 1);
  	sdev->rds_tp = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_RDS_TX_TRAFFIC_PROGRAM, 0, 1, 1, 0);
  	sdev->rds_ta = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_RDS_TX_TRAFFIC_ANNOUNCEMENT, 0, 1, 1, 0);
  	sdev->rds_ms = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_RDS_TX_MUSIC_SPEECH, 0, 1, 1, 1);
  	sdev->rds_dyn_pty = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_RDS_TX_DYNAMIC_PTY, 0, 1, 1, 0);
  	sdev->rds_alt_freqs_enable = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_RDS_TX_ALT_FREQS_ENABLE, 0, 1, 1, 0);
  	sdev->rds_alt_freqs = v4l2_ctrl_new_custom(hdl, &si4713_alt_freqs_ctrl, NULL);
  	sdev->rds_deviation = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_RDS_TX_DEVIATION, 0, MAX_RDS_DEVIATION,
  			10, DEFAULT_RDS_DEVIATION);
  	/*
  	 * Report step as 8. From RDS spec, psname
  	 * should be 8. But there are receivers which scroll strings
  	 * sized as 8xN.
  	 */
  	sdev->rds_ps_name = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_RDS_TX_PS_NAME, 0, MAX_RDS_PS_NAME, 8, 0);
  	/*
  	 * Report step as 32 (2A block). From RDS spec,
  	 * radio text should be 32 for 2A block. But there are receivers
  	 * which scroll strings sized as 32xN. Setting default to 32.
  	 */
  	sdev->rds_radio_text = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_RDS_TX_RADIO_TEXT, 0, MAX_RDS_RADIO_TEXT, 32, 0);
  
  	sdev->limiter_enabled = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_AUDIO_LIMITER_ENABLED, 0, 1, 1, 1);
  	sdev->limiter_release_time = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_AUDIO_LIMITER_RELEASE_TIME, 250,
  			MAX_LIMITER_RELEASE_TIME, 10, DEFAULT_LIMITER_RTIME);
  	sdev->limiter_deviation = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_AUDIO_LIMITER_DEVIATION, 0,
  			MAX_LIMITER_DEVIATION, 10, DEFAULT_LIMITER_DEV);
  
  	sdev->compression_enabled = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_AUDIO_COMPRESSION_ENABLED, 0, 1, 1, 1);
  	sdev->compression_gain = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_AUDIO_COMPRESSION_GAIN, 0, MAX_ACOMP_GAIN, 1,
  			DEFAULT_ACOMP_GAIN);
  	sdev->compression_threshold = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_AUDIO_COMPRESSION_THRESHOLD,
  			MIN_ACOMP_THRESHOLD, MAX_ACOMP_THRESHOLD, 1,
  			DEFAULT_ACOMP_THRESHOLD);
  	sdev->compression_attack_time = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_AUDIO_COMPRESSION_ATTACK_TIME, 0,
  			MAX_ACOMP_ATTACK_TIME, 500, DEFAULT_ACOMP_ATIME);
  	sdev->compression_release_time = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_AUDIO_COMPRESSION_RELEASE_TIME, 100000,
  			MAX_ACOMP_RELEASE_TIME, 100000, DEFAULT_ACOMP_RTIME);
  
  	sdev->pilot_tone_enabled = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_PILOT_TONE_ENABLED, 0, 1, 1, 1);
  	sdev->pilot_tone_deviation = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_PILOT_TONE_DEVIATION, 0, MAX_PILOT_DEVIATION,
  			10, DEFAULT_PILOT_DEVIATION);
  	sdev->pilot_tone_freq = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_PILOT_TONE_FREQUENCY, 0, MAX_PILOT_FREQUENCY,
  			1, DEFAULT_PILOT_FREQUENCY);
  
  	sdev->tune_preemphasis = v4l2_ctrl_new_std_menu(hdl, &si4713_ctrl_ops,
  			V4L2_CID_TUNE_PREEMPHASIS,
  			V4L2_PREEMPHASIS_75_uS, 0, V4L2_PREEMPHASIS_50_uS);
  	sdev->tune_pwr_level = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_TUNE_POWER_LEVEL, 0, SI4713_MAX_POWER,
  			1, DEFAULT_POWER_LEVEL);
  	sdev->tune_ant_cap = v4l2_ctrl_new_std(hdl, &si4713_ctrl_ops,
  			V4L2_CID_TUNE_ANTENNA_CAPACITOR, 0, SI4713_MAX_ANTCAP,
  			1, 0);
  
  	if (hdl->error) {
  		rval = hdl->error;
  		goto free_ctrls;
  	}
  	v4l2_ctrl_cluster(29, &sdev->mute);
  	sdev->sd.ctrl_handler = hdl;
  
  	if (client->irq) {
  		rval = devm_request_irq(&client->dev, client->irq,
  			si4713_handler, IRQF_TRIGGER_FALLING,
  			client->name, sdev);
  		if (rval < 0) {
  			v4l2_err(&sdev->sd, "Could not request IRQ
  ");
  			goto free_ctrls;
  		}
  		v4l2_dbg(1, debug, &sdev->sd, "IRQ requested.
  ");
  	} else {
  		v4l2_warn(&sdev->sd, "IRQ not configured. Using timeouts.
  ");
  	}
  
  	rval = si4713_initialize(sdev);
  	if (rval < 0) {
  		v4l2_err(&sdev->sd, "Failed to probe device information.
  ");
  		goto free_ctrls;
  	}
  
  	if (!np && (!pdata || !pdata->is_platform_device))
  		return 0;
  
  	si4713_pdev = platform_device_alloc("radio-si4713", -1);
  	if (!si4713_pdev) {
  		rval = -ENOMEM;
  		goto put_main_pdev;
  	}
  
  	si4713_pdev_pdata.subdev = client;
  	rval = platform_device_add_data(si4713_pdev, &si4713_pdev_pdata,
  					sizeof(si4713_pdev_pdata));
  	if (rval)
  		goto put_main_pdev;
  
  	rval = platform_device_add(si4713_pdev);
  	if (rval)
  		goto put_main_pdev;
  
  	sdev->pd = si4713_pdev;
  
  	return 0;
  
  put_main_pdev:
  	platform_device_put(si4713_pdev);
  	v4l2_device_unregister_subdev(&sdev->sd);
  free_ctrls:
  	v4l2_ctrl_handler_free(hdl);
  exit:
  	return rval;
  }
  
  /* si4713_remove - remove the device */
  static int si4713_remove(struct i2c_client *client)
  {
  	struct v4l2_subdev *sd = i2c_get_clientdata(client);
  	struct si4713_device *sdev = to_si4713_device(sd);
  
  	platform_device_unregister(sdev->pd);
  
  	if (sdev->power_state)
  		si4713_set_power_state(sdev, POWER_DOWN);
  
  	v4l2_device_unregister_subdev(sd);
  	v4l2_ctrl_handler_free(sd->ctrl_handler);
  
  	return 0;
  }
  
  /* si4713_i2c_driver - i2c driver interface */
  static const struct i2c_device_id si4713_id[] = {
  	{ "si4713" , 0 },
  	{ },
  };
  MODULE_DEVICE_TABLE(i2c, si4713_id);
  
  static struct i2c_driver si4713_i2c_driver = {
  	.driver		= {
  		.name	= "si4713",
  	},
  	.probe		= si4713_probe,
  	.remove         = si4713_remove,
  	.id_table       = si4713_id,
  };
  
  module_i2c_driver(si4713_i2c_driver);