path: root/drivers/media/radio/radio-si476x.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * drivers/media/radio/radio-si476x.c -- V4L2 driver for SI476X chips
 *
 * Copyright (C) 2012 Innovative Converged Devices(ICD)
 * Copyright (C) 2013 Andrey Smirnov
 *
 * Author: Andrey Smirnov <andrew.smirnov@gmail.com>
 */

#include <linux/module.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/atomic.h>
#include <linux/videodev2.h>
#include <linux/mutex.h>
#include <linux/debugfs.h>
#include <media/v4l2-common.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-event.h>
#include <media/v4l2-device.h>

#include <media/drv-intf/si476x.h>
#include <linux/mfd/si476x-core.h>

#define FM_FREQ_RANGE_LOW   64000000
#define FM_FREQ_RANGE_HIGH 108000000

#define AM_FREQ_RANGE_LOW    520000
#define AM_FREQ_RANGE_HIGH 30000000

#define PWRLINEFLTR (1 << 8)

#define FREQ_MUL (10000000 / 625)

#define SI476X_PHDIV_STATUS_LINK_LOCKED(status) (0x80 & (status))

#define DRIVER_NAME "si476x-radio"
#define DRIVER_CARD "SI476x AM/FM Receiver"

enum si476x_freq_bands {
	SI476X_BAND_FM,
	SI476X_BAND_AM,
};

static const struct v4l2_frequency_band si476x_bands[] = {
	[SI476X_BAND_FM] = {
		.type		= V4L2_TUNER_RADIO,
		.index		= SI476X_BAND_FM,
		.capability	= V4L2_TUNER_CAP_LOW
		| V4L2_TUNER_CAP_STEREO
		| V4L2_TUNER_CAP_RDS
		| V4L2_TUNER_CAP_RDS_BLOCK_IO
		| V4L2_TUNER_CAP_FREQ_BANDS,
		.rangelow	=  64 * FREQ_MUL,
		.rangehigh	= 108 * FREQ_MUL,
		.modulation	= V4L2_BAND_MODULATION_FM,
	},
	[SI476X_BAND_AM] = {
		.type		= V4L2_TUNER_RADIO,
		.index		= SI476X_BAND_AM,
		.capability	= V4L2_TUNER_CAP_LOW
		| V4L2_TUNER_CAP_FREQ_BANDS,
		.rangelow	= 0.52 * FREQ_MUL,
		.rangehigh	= 30 * FREQ_MUL,
		.modulation	= V4L2_BAND_MODULATION_AM,
	},
};

static inline bool si476x_radio_freq_is_inside_of_the_band(u32 freq, int band)
{
	return freq >= si476x_bands[band].rangelow &&
		freq <= si476x_bands[band].rangehigh;
}

static inline bool si476x_radio_range_is_inside_of_the_band(u32 low, u32 high,
							    int band)
{
	return low  >= si476x_bands[band].rangelow &&
		high <= si476x_bands[band].rangehigh;
}

static int si476x_radio_s_ctrl(struct v4l2_ctrl *ctrl);
static int si476x_radio_g_volatile_ctrl(struct v4l2_ctrl *ctrl);

enum phase_diversity_modes_idx {
	SI476X_IDX_PHDIV_DISABLED,
	SI476X_IDX_PHDIV_PRIMARY_COMBINING,
	SI476X_IDX_PHDIV_PRIMARY_ANTENNA,
	SI476X_IDX_PHDIV_SECONDARY_ANTENNA,
	SI476X_IDX_PHDIV_SECONDARY_COMBINING,
};

static const char * const phase_diversity_modes[] = {
	[SI476X_IDX_PHDIV_DISABLED]		= "Disabled",
	[SI476X_IDX_PHDIV_PRIMARY_COMBINING]	= "Primary with Secondary",
	[SI476X_IDX_PHDIV_PRIMARY_ANTENNA]	= "Primary Antenna",
	[SI476X_IDX_PHDIV_SECONDARY_ANTENNA]	= "Secondary Antenna",
	[SI476X_IDX_PHDIV_SECONDARY_COMBINING]	= "Secondary with Primary",
};

static inline enum phase_diversity_modes_idx
si476x_phase_diversity_mode_to_idx(enum si476x_phase_diversity_mode mode)
{
	switch (mode) {
	default:		/* FALLTHROUGH */
	case SI476X_PHDIV_DISABLED:
		return SI476X_IDX_PHDIV_DISABLED;
	case SI476X_PHDIV_PRIMARY_COMBINING:
		return SI476X_IDX_PHDIV_PRIMARY_COMBINING;
	case SI476X_PHDIV_PRIMARY_ANTENNA:
		return SI476X_IDX_PHDIV_PRIMARY_ANTENNA;
	case SI476X_PHDIV_SECONDARY_ANTENNA:
		return SI476X_IDX_PHDIV_SECONDARY_ANTENNA;
	case SI476X_PHDIV_SECONDARY_COMBINING:
		return SI476X_IDX_PHDIV_SECONDARY_COMBINING;
	}
}

static inline enum si476x_phase_diversity_mode
si476x_phase_diversity_idx_to_mode(enum phase_diversity_modes_idx idx)
{
	static const int idx_to_value[] = {
		[SI476X_IDX_PHDIV_DISABLED]		= SI476X_PHDIV_DISABLED,
		[SI476X_IDX_PHDIV_PRIMARY_COMBINING]	= SI476X_PHDIV_PRIMARY_COMBINING,
		[SI476X_IDX_PHDIV_PRIMARY_ANTENNA]	= SI476X_PHDIV_PRIMARY_ANTENNA,
		[SI476X_IDX_PHDIV_SECONDARY_ANTENNA]	= SI476X_PHDIV_SECONDARY_ANTENNA,
		[SI476X_IDX_PHDIV_SECONDARY_COMBINING]	= SI476X_PHDIV_SECONDARY_COMBINING,
	};

	return idx_to_value[idx];
}

static const struct v4l2_ctrl_ops si476x_ctrl_ops = {
	.g_volatile_ctrl	= si476x_radio_g_volatile_ctrl,
	.s_ctrl			= si476x_radio_s_ctrl,
};


enum si476x_ctrl_idx {
	SI476X_IDX_RSSI_THRESHOLD,
	SI476X_IDX_SNR_THRESHOLD,
	SI476X_IDX_MAX_TUNE_ERROR,
	SI476X_IDX_HARMONICS_COUNT,
	SI476X_IDX_DIVERSITY_MODE,
	SI476X_IDX_INTERCHIP_LINK,
};
static struct v4l2_ctrl_config si476x_ctrls[] = {

	/*
	 * SI476X during its station seeking(or tuning) process uses several
	 * parameters to detrmine if "the station" is valid:
	 *
	 *	- Signal's SNR(in dBuV) must be lower than
	 *	#V4L2_CID_SI476X_SNR_THRESHOLD
	 *	- Signal's RSSI(in dBuV) must be greater than
	 *	#V4L2_CID_SI476X_RSSI_THRESHOLD
	 *	- Signal's frequency deviation(in units of 2ppm) must not be
	 *	more than #V4L2_CID_SI476X_MAX_TUNE_ERROR
	 */
	[SI476X_IDX_RSSI_THRESHOLD] = {
		.ops	= &si476x_ctrl_ops,
		.id	= V4L2_CID_SI476X_RSSI_THRESHOLD,
		.name	= "Valid RSSI Threshold",
		.type	= V4L2_CTRL_TYPE_INTEGER,
		.min	= -128,
		.max	= 127,
		.step	= 1,
	},
	[SI476X_IDX_SNR_THRESHOLD] = {
		.ops	= &si476x_ctrl_ops,
		.id	= V4L2_CID_SI476X_SNR_THRESHOLD,
		.type	= V4L2_CTRL_TYPE_INTEGER,
		.name	= "Valid SNR Threshold",
		.min	= -128,
		.max	= 127,
		.step	= 1,
	},
	[SI476X_IDX_MAX_TUNE_ERROR] = {
		.ops	= &si476x_ctrl_ops,
		.id	= V4L2_CID_SI476X_MAX_TUNE_ERROR,
		.type	= V4L2_CTRL_TYPE_INTEGER,
		.name	= "Max Tune Errors",
		.min	= 0,
		.max	= 126 * 2,
		.step	= 2,
	},

	/*
	 * #V4L2_CID_SI476X_HARMONICS_COUNT -- number of harmonics
	 * built-in power-line noise supression filter is to reject
	 * during AM-mode operation.
	 */
	[SI476X_IDX_HARMONICS_COUNT] = {
		.ops	= &si476x_ctrl_ops,
		.id	= V4L2_CID_SI476X_HARMONIC