alistair23-linux/drivers/media/radio/tea575x.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *   ALSA driver for TEA5757/5759 Philips AM/FM radio tuner chips
 *
 *	Copyright (c) 2004 Jaroslav Kysela <perex@perex.cz>
 */

#include <linux/delay.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <asm/io.h>
#include <media/v4l2-device.h>
#include <media/v4l2-dev.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-event.h>
#include <media/drv-intf/tea575x.h>

MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
MODULE_DESCRIPTION("Routines for control of TEA5757/5759 Philips AM/FM radio tuner chips");
MODULE_LICENSE("GPL");

/*
 * definitions
 */

#define TEA575X_BIT_SEARCH	(1<<24)		/* 1 = search action, 0 = tuned */
#define TEA575X_BIT_UPDOWN	(1<<23)		/* 0 = search down, 1 = search up */
#define TEA575X_BIT_MONO	(1<<22)		/* 0 = stereo, 1 = mono */
#define TEA575X_BIT_BAND_MASK	(3<<20)
#define TEA575X_BIT_BAND_FM	(0<<20)
#define TEA575X_BIT_BAND_MW	(1<<20)
#define TEA575X_BIT_BAND_LW	(2<<20)
#define TEA575X_BIT_BAND_SW	(3<<20)
#define TEA575X_BIT_PORT_0	(1<<19)		/* user bit */
#define TEA575X_BIT_PORT_1	(1<<18)		/* user bit */
#define TEA575X_BIT_SEARCH_MASK	(3<<16)		/* search level */
#define TEA575X_BIT_SEARCH_5_28	     (0<<16)	/* FM >5uV, AM >28uV */
#define TEA575X_BIT_SEARCH_10_40     (1<<16)	/* FM >10uV, AM > 40uV */
#define TEA575X_BIT_SEARCH_30_63     (2<<16)	/* FM >30uV, AM > 63uV */
#define TEA575X_BIT_SEARCH_150_1000  (3<<16)	/* FM > 150uV, AM > 1000uV */
#define TEA575X_BIT_DUMMY	(1<<15)		/* buffer */
#define TEA575X_BIT_FREQ_MASK	0x7fff

enum { BAND_FM, BAND_FM_JAPAN, BAND_AM };

static const struct v4l2_frequency_band bands[] = {
	{
		.type = V4L2_TUNER_RADIO,
		.index = 0,
		.capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
			      V4L2_TUNER_CAP_FREQ_BANDS,
		.rangelow   =  87500 * 16,
		.rangehigh  = 108000 * 16,
		.modulation = V4L2_BAND_MODULATION_FM,
	},
	{
		.type = V4L2_TUNER_RADIO,
		.index = 0,
		.capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
			      V4L2_TUNER_CAP_FREQ_BANDS,
		.rangelow   = 76000 * 16,
		.rangehigh  = 91000 * 16,
		.modulation = V4L2_BAND_MODULATION_FM,
	},
	{
		.type = V4L2_TUNER_RADIO,
		.index = 1,
		.capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_FREQ_BANDS,
		.rangelow   =  530 * 16,
		.rangehigh  = 1710 * 16,
		.modulation = V4L2_BAND_MODULATION_AM,
	},
};

/*
 * lowlevel part
 */

static void snd_tea575x_write(struct snd_tea575x *tea, unsigned int val)
{
	u16 l;
	u8 data;

	if (tea->ops->write_val)
		return tea->ops->write_val(tea, val);

	tea->ops->set_direction(tea, 1);
	udelay(16);

	for (l = 25; l > 0; l--) {
		data = (val >> 24) & TEA575X_DATA;
		val <<= 1;			/* shift data */
		tea->ops->set_pins(tea, data | TEA575X_WREN);
		udelay(2);
		tea->ops->set_pins(tea, data | TEA575X_WREN | TEA575X_CLK);
		udelay(2);
		tea->ops->set_pins(tea, data | TEA575X_WREN);
		udelay(2);
	}

	if (!tea->mute)
		tea->ops->set_pins(tea, 0);
}

static u32 snd_tea575x_read(struct snd_tea575x *tea)
{
	u16 l, rdata;
	u32 data = 0;

	if (tea->ops->read_val)
		return tea->ops->read_val(tea);

	tea->ops->set_direction(tea, 0);
	tea->ops->set_pins(tea, 0);
	udelay(16);

	for (l = 24; l--;) {
		tea->ops->set_pins(tea, TEA575X_CLK);
		udelay(2);
		if (!l)
			tea->tuned = tea->ops->get_pins(tea) & TEA575X_MOST ? 0 : 1;
		tea->ops->set_pins(tea, 0);
		udelay(2);
		data <<= 1;			/* shift data */
		rdata = tea->ops->get_pins(tea);
		if (!l)
			tea->stereo = (rdata & TEA575X_MOST) ?  0 : 1;
		if (rdata & TEA575X_DATA)
			data++;
		udelay(2);
	}

	if (tea->mute)
		tea->ops->set_pins(tea, TEA575X_WREN);

	return data;
}

static u32 snd_tea575x_val_to_freq(struct snd_tea575x *tea, u32 val)
{
	u32 freq = val & TEA575X_BIT_FREQ_MASK;

	if (freq == 0)
		return freq;

	switch (tea->band) {
	case BAND_FM:
		/* freq *= 12.5 */
		freq *= 125;
		freq /= 10;
		/* crystal fixup */
		freq -= TEA575X_FMIF;
		break;
	case BAND_FM_JAPAN:
		/* freq *= 12.5 */
		freq *= 125;
		freq /= 10;
		/* crystal fixup */
		freq += TEA575X_FMIF;
		break;
	case BAND_AM:
		/* crystal fixup */
		freq -= TEA575X_AMIF;
		break;
	}

	return clamp(freq * 16, bands[tea->band].rangelow,
				bands[tea->band].rangehigh); /* from kHz */
}

static u32 snd_tea575x_get_freq(struct snd_tea575x *tea)
{
	return snd_tea575x_val_to_freq(tea, snd_tea575x_read(tea));
}

void snd_tea575x_set_freq(struct snd_tea575x *tea)
{
	u32 freq = tea->freq / 16;	/* to kHz */
	u32 band = 0;

	switch (tea->band) {
	case BAND_FM:
		band = TEA575X_BIT_BAND_FM;
		/* crystal fixup */
		freq += TEA575X_FMIF;
		/* freq /= 12.5 */
		freq *= 10;
		freq /= 125;
		break;
	case BAND_FM_JAPAN:
		band = TEA575X_BIT_BAND_FM;
		/* crystal fixup */
		freq -= TEA575X_FMIF;
		/* freq /= 12.5 */
		freq *= 10;
		freq /= 125;
		break;
	case BAND_AM:
		band = TEA575X_BIT_BAND_MW;
		/* crystal fixup */
		freq += TEA575X_AMIF;
		break;
	}

	tea->val &= ~(TEA575X_BIT_FREQ_MASK | TEA575X_BIT_BAND_MASK);
	tea->val |= band;
	tea->val |= freq & TEA575X_BIT_FREQ_MASK;
	snd_tea575x_write(tea, tea->val);
	tea->freq = snd_tea575x_val_to_freq(tea, tea->val);
}
EXPORT_SYMBOL(snd_tea575x_set_freq);

/*
 * Linux Video interface
 */

static int vidioc_querycap(struct file *file, void  *priv,
					struct v4l2_capability *v)
{
	struct snd_tea575x *tea = video_drvdata(file);

	strscpy(v->driver, tea->v4l2_dev->name, sizeof(v->driver));
	strscpy(v->card, tea->card, sizeof(v->card));
	strlcat(v->card, tea->tea5759 ? " TEA5759" : " TEA5757", sizeof(v->card));
	strscpy(v->bus_info, tea->bus_info, sizeof(v->bus_info));
	return 0;
}

int snd_tea575x_enum_freq_bands(struct snd_tea575x *tea,
					struct v4l2_frequency_band *band)
{
	int index;

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

	switch (band->index) {
	case 0:
		if (tea->tea5759)
			index = BAND_FM_JAPAN;
		else
			index = BAND_FM;
		break;
	case 1:
		if (tea->has_am) {
			index = BAND_AM;
			break;
		}
		/* Fall through */
	default:
		return -EINVAL;
	}

	*band = bands[index];
	if (!tea->cannot_read_data)
		band->capability |= V4L2_TUNER_CAP_HWSEEK_BOUNDED;

	return 0;
}
EXPORT_SYMBOL(snd_tea575x_enum_freq_bands);

static int vidioc_enum_freq_bands(struct file *file, void *priv,
					 struct v4l2_frequency_band *band)
{
	struct snd_tea575x *tea = video_drvdata(file);

	return snd_tea575x_enum_freq_bands(tea, band);
}

int snd_tea575x_g_tuner(struct snd_tea575x *tea, struct v4l2_tuner *v)
{
	struct v4l2_frequency_band band_fm = { 0, };

	if (v->index > 0)
		return -EINVAL;

	snd_tea575x_read(tea);
	snd_tea575x_enum_freq_bands(tea, &band_fm);

	memset(v, 0, sizeof(*v));
	strscpy(v->name, tea->has_am ? "FM/AM" : "FM", sizeof(v->name));
	v->type = V4L2_TUNER_RADIO;
	v->capability = band_fm.capability;
	v->rangelow = tea->has_am ? bands[BAND_AM].rangelow : band_fm.rangelow;
	v->rangehigh = band_fm.rangehigh;
	v->rxsubchans = tea->stereo ? V4L2_TUNER_SUB_STEREO : V4L2_TUNER_SUB_MONO;
	v->audmode = (tea->val & TEA575X_BIT_MONO) ?
		V4L2_TUNER_MODE_MONO : V4L2_TUNER_MODE_STEREO;
	v->signal = tea->tuned ? 0xffff : 0;
	return 0;
}
EXPORT_SYMBOL(snd_tea575x_g_tuner);

static int vidioc_g_tuner(struct file *file, void *priv,
					struct v4l2_tuner *v)
{
	struct snd_tea575x *tea = video_drvdata(file);

	return snd_tea575x_g_tuner(tea, v);
}

static int vidioc_s_tuner(struct file *file, void *priv,
					const struct v4l2_tuner *v)
{
	struct snd_tea575x *tea = video_drvdata(file);
	u32 orig_val = tea->val;

	if (v->index)
		return -EINVAL;
	tea->val &= ~TEA575X_BIT_MONO;
	if (v->audmode == V4L2_TUNER_MODE_MONO)
		tea->val |= TEA575X_BIT_MONO;
	/* Only apply changes if currently tuning FM */
	if (tea->band != BAND_AM && tea->val != orig_val)
		snd_tea575x_set_freq(tea);

	return 0;
}

static int vidioc_g_frequency(struct file *file, void *priv,
					struct v4l2_frequency *f)
{
	struct snd_tea575x *tea = video_drvdata(file);

	if (f->tuner != 0)
		return -EINVAL;
	f->type = V4L2_TUNER_RADIO;
	f->frequency = tea->freq;
	return 0;
}

static int vidioc_s_frequency(struct file *file, void *priv,
					const struct v4l2_frequency *f)
{
	struct snd_tea575x *tea = video_drvdata(file);

	if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
		return -EINVAL;

	if (tea->has_am && f->frequency < (20000 * 16))
		tea->band = BAND_AM;
	else if (tea->tea5759)
		tea->band = BAND_FM_JAPAN;
	else
		tea->band = BAND_FM;

	tea->freq = clamp_t(u32, f->frequency, bands[tea->band].rangelow,
					bands[tea->band].rangehigh);
	snd_tea575x_set_freq(tea);
	return 0;
}

int snd_tea575x_s_hw_freq_seek(struct file *file, struct snd_tea575x *tea,
				const struct v4l2_hw_freq_seek *a)
{
	unsigned long timeout;
	int i, spacing;

	if (tea->cannot_read_data)
		return -ENOTTY;
	if (a->tuner || a->wrap_around)
		return -EINVAL;

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

	if (a->rangelow || a->rangehigh) {
		for (i = 0; i < ARRAY_SIZE(bands); i++) {
			if ((i == BAND_FM && tea->tea5759) ||
			    (i == BAND_FM_JAPAN && !tea->tea5759) ||
			    (i == BAND_AM && !tea->has_am))
				continue;
			if (bands[i].rangelow  == a->rangelow &&
			    bands[i].rangehigh == a->rangehigh)
				break;
		}
		if (i == ARRAY_SIZE(bands))
			return -EINVAL; /* No matching band found */
		if (i != tea->band) {
			tea->band = i;
			tea->freq = clamp(tea->freq, bands[i].rangelow,
						     bands[i].rangehigh);
			snd_tea575x_set_freq(tea);
		}
	}

	spacing = (tea->band == BAND_AM) ? 5 : 50; /* kHz */

	/* clear the frequency, HW will fill it in */
	tea->val &= ~TEA575X_BIT_FREQ_MASK;
	tea->val |= TEA575X_BIT_SEARCH;
	if (a->seek_upward)
		tea->val |= TEA575X_BIT_UPDOWN;
	else
		tea->val &= ~TEA575X_BIT_UPDOWN;
	snd_tea575x_write(tea, tea->val);
	timeout = jiffies + msecs_to_jiffies(10000);
	for (;;) {
		if (time_after(jiffies, timeout))
			break;
		if (schedule_timeout_interruptible(msecs_to_jiffies(10))) {
			/* some signal arrived, stop search */
			tea->val &= ~TEA575X_BIT_SEARCH;
			snd_tea575x_set_freq(tea);
			return -ERESTARTSYS;
		}
		if (!(snd_tea575x_read(tea) & TEA575X_BIT_SEARCH)) {
			u32 freq;

			/* Found a frequency, wait until it can be read */
			for (i = 0; i < 100; i++) {
				msleep(10);
				freq = snd_tea575x_get_freq(tea);
				if (freq) /* available */
					break;
			}
			if (freq == 0) /* shouldn't happen */
				break;
			/*
			 * if we moved by less than the spacing, or in the
			 * wrong direction, continue seeking
			 */
			if (abs(tea->freq - freq) < 16 * spacing ||
					(a->seek_upward && freq < tea->freq) ||
					(!a->seek_upward && freq > tea->freq)) {
				snd_tea575x_write(tea, tea->val);
				continue;
			}
			tea->freq = freq;
			tea->val &= ~TEA575X_BIT_SEARCH;
			return 0;
		}
	}
	tea->val &= ~TEA575X_BIT_SEARCH;
	snd_tea575x_set_freq(tea);
	return -ENODATA;
}
EXPORT_SYMBOL(snd_tea575x_s_hw_freq_seek);

static int vidioc_s_hw_freq_seek(struct file *file, void *fh,
					const struct v4l2_hw_freq_seek *a)
{
	struct snd_tea575x *tea = video_drvdata(file);

	return snd_tea575x_s_hw_freq_seek(file, tea, a);
}

static int tea575x_s_ctrl(struct v4l2_ctrl *ctrl)
{
	struct snd_tea575x *tea = container_of(ctrl->handler, struct snd_tea575x, ctrl_handler);

	switch (ctrl->id) {
	case V4L2_CID_AUDIO_MUTE:
		tea->mute = ctrl->val;
		snd_tea575x_set_freq(tea);
		return 0;
	}

	return -EINVAL;
}

static const struct v4l2_file_operations tea575x_fops = {
	.unlocked_ioctl	= video_ioctl2,
	.open           = v4l2_fh_open,
	.release        = v4l2_fh_release,
	.poll           = v4l2_ctrl_poll,
};

static const struct v4l2_ioctl_ops tea575x_ioctl_ops = {
	.vidioc_querycap    = vidioc_querycap,
	.vidioc_g_tuner     = vidioc_g_tuner,
	.vidioc_s_tuner     = vidioc_s_tuner,
	.vidioc_g_frequency = vidioc_g_frequency,
	.vidioc_s_frequency = vidioc_s_frequency,
	.vidioc_s_hw_freq_seek = vidioc_s_hw_freq_seek,
	.vidioc_enum_freq_bands = vidioc_enum_freq_bands,
	.vidioc_log_status  = v4l2_ctrl_log_status,
	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
};

static const struct video_device tea575x_radio = {
	.ioctl_ops	= &tea575x_ioctl_ops,
	.release        = video_device_release_empty,
};

static const struct v4l2_ctrl_ops tea575x_ctrl_ops = {
	.s_ctrl = tea575x_s_ctrl,
};


int snd_tea575x_hw_init(struct snd_tea575x *tea)
{
	tea->mute = true;

	/* Not all devices can or know how to read the data back.
	   Such devices can set cannot_read_data to true. */
	if (!tea->cannot_read_data) {
		snd_tea575x_write(tea, 0x55AA);
		if (snd_tea575x_read(tea) != 0x55AA)
			return -ENODEV;
	}

	tea->val = TEA575X_BIT_BAND_FM | TEA575X_BIT_SEARCH_5_28;
	tea->freq = 90500 * 16;		/* 90.5Mhz default */
	snd_tea575x_set_freq(tea);

	return 0;
}
EXPORT_SYMBOL(snd_tea575x_hw_init);

int snd_tea575x_init(struct snd_tea575x *tea, struct module *owner)
{
	int retval = snd_tea575x_hw_init(tea);

	if (retval)
		return retval;

	tea->vd = tea575x_radio;
	video_set_drvdata(&tea->vd, tea);
	mutex_init(&tea->mutex);
	strscpy(tea->vd.name, tea->v4l2_dev->name, sizeof(tea->vd.name));
	tea->vd.lock = &tea->mutex;
	tea->vd.v4l2_dev = tea->v4l2_dev;
	tea->vd.device_caps = V4L2_CAP_TUNER | V4L2_CAP_RADIO;
	if (!tea->cannot_read_data)
		tea->vd.device_caps |= V4L2_CAP_HW_FREQ_SEEK;
	tea->fops = tea575x_fops;
	tea->fops.owner = owner;
	tea->vd.fops = &tea->fops;
	/* disable hw_freq_seek if we can't use it */
	if (tea->cannot_read_data)
		v4l2_disable_ioctl(&tea->vd, VIDIOC_S_HW_FREQ_SEEK);

	if (!tea->cannot_mute) {
		tea->vd.ctrl_handler = &tea->ctrl_handler;
		v4l2_ctrl_handler_init(&tea->ctrl_handler, 1);
		v4l2_ctrl_new_std(&tea->ctrl_handler, &tea575x_ctrl_ops,
				  V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
		retval = tea->ctrl_handler.error;
		if (retval) {
			v4l2_err(tea->v4l2_dev, "can't initialize controls\n");
			v4l2_ctrl_handler_free(&tea->ctrl_handler);
			return retval;
		}

		if (tea->ext_init) {
			retval = tea->ext_init(tea);
			if (retval) {
				v4l2_ctrl_handler_free(&tea->ctrl_handler);
				return retval;
			}
		}

		v4l2_ctrl_handler_setup(&tea->ctrl_handler);
	}

	retval = video_register_device(&tea->vd, VFL_TYPE_RADIO, tea->radio_nr);
	if (retval) {
		v4l2_err(tea->v4l2_dev, "can't register video device!\n");
		v4l2_ctrl_handler_free(tea->vd.ctrl_handler);
		return retval;
	}

	return 0;
}
EXPORT_SYMBOL(snd_tea575x_init);

void snd_tea575x_exit(struct snd_tea575x *tea)
{
	video_unregister_device(&tea->vd);
	v4l2_ctrl_handler_free(tea->vd.ctrl_handler);
}
EXPORT_SYMBOL(snd_tea575x_exit);