radio-si470x.c

来自「trident tm5600的linux驱动」· C语言 代码 · 共 1,789 行 · 第 1/4 页

 * si470x_device - private data
 */
struct si470x_device {
	/* reference to USB and video device */
	struct usb_device *usbdev;
	struct usb_interface *intf;
	struct video_device *videodev;

	/* driver management */
	unsigned int users;
	unsigned char disconnected;
	struct mutex disconnect_lock;

	/* Silabs internal registers (0..15) */
	unsigned short registers[RADIO_REGISTER_NUM];

	/* RDS receive buffer */
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
	struct work_struct work;
#else
	struct delayed_work work;
#endif
	wait_queue_head_t read_queue;
	struct mutex lock;		/* buffer locking */
	unsigned char *buffer;		/* size is always multiple of three */
	unsigned int buf_size;
	unsigned int rd_index;
	unsigned int wr_index;
};


/*
 * The frequency is set in units of 62.5 Hz when using V4L2_TUNER_CAP_LOW,
 * 62.5 kHz otherwise.
 * The tuner is able to have a channel spacing of 50, 100 or 200 kHz.
 * tuner->capability is therefore set to V4L2_TUNER_CAP_LOW
 * The FREQ_MUL is then: 1 MHz / 62.5 Hz = 16000
 */
#define FREQ_MUL (1000000 / 62.5)



/**************************************************************************
 * General Driver Functions
 **************************************************************************/

/*
 * si470x_get_report - receive a HID report
 */
static int si470x_get_report(struct si470x_device *radio, void *buf, int size)
{
	unsigned char *report = (unsigned char *) buf;
	int retval;

	retval = usb_control_msg(radio->usbdev,
		usb_rcvctrlpipe(radio->usbdev, 0),
		HID_REQ_GET_REPORT,
		USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
		report[0], 2,
		buf, size, usb_timeout);

	if (retval < 0)
		printk(KERN_WARNING DRIVER_NAME
			": si470x_get_report: usb_control_msg returned %d\n",
			retval);
	return retval;
}


/*
 * si470x_set_report - send a HID report
 */
static int si470x_set_report(struct si470x_device *radio, void *buf, int size)
{
	unsigned char *report = (unsigned char *) buf;
	int retval;

	retval = usb_control_msg(radio->usbdev,
		usb_sndctrlpipe(radio->usbdev, 0),
		HID_REQ_SET_REPORT,
		USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
		report[0], 2,
		buf, size, usb_timeout);

	if (retval < 0)
		printk(KERN_WARNING DRIVER_NAME
			": si470x_set_report: usb_control_msg returned %d\n",
			retval);
	return retval;
}


/*
 * si470x_get_register - read register
 */
static int si470x_get_register(struct si470x_device *radio, int regnr)
{
	unsigned char buf[REGISTER_REPORT_SIZE];
	int retval;

	buf[0] = REGISTER_REPORT(regnr);

	retval = si470x_get_report(radio, (void *) &buf, sizeof(buf));

	if (retval >= 0)
		radio->registers[regnr] = get_unaligned_be16(&buf[1]);

	return (retval < 0) ? -EINVAL : 0;
}


/*
 * si470x_set_register - write register
 */
static int si470x_set_register(struct si470x_device *radio, int regnr)
{
	unsigned char buf[REGISTER_REPORT_SIZE];
	int retval;

	buf[0] = REGISTER_REPORT(regnr);
	put_unaligned_be16(radio->registers[regnr], &buf[1]);

	retval = si470x_set_report(radio, (void *) &buf, sizeof(buf));

	return (retval < 0) ? -EINVAL : 0;
}


/*
 * si470x_get_all_registers - read entire registers
 */
static int si470x_get_all_registers(struct si470x_device *radio)
{
	unsigned char buf[ENTIRE_REPORT_SIZE];
	int retval;
	unsigned char regnr;

	buf[0] = ENTIRE_REPORT;

	retval = si470x_get_report(radio, (void *) &buf, sizeof(buf));

	if (retval >= 0)
		for (regnr = 0; regnr < RADIO_REGISTER_NUM; regnr++)
			radio->registers[regnr] = get_unaligned_be16(
				&buf[regnr * RADIO_REGISTER_SIZE + 1]);

	return (retval < 0) ? -EINVAL : 0;
}


/*
 * si470x_get_rds_registers - read rds registers
 */
static int si470x_get_rds_registers(struct si470x_device *radio)
{
	unsigned char buf[RDS_REPORT_SIZE];
	int retval;
	int size;
	unsigned char regnr;

	buf[0] = RDS_REPORT;

	retval = usb_interrupt_msg(radio->usbdev,
		usb_rcvintpipe(radio->usbdev, 1),
		(void *) &buf, sizeof(buf), &size, usb_timeout);
	if (size != sizeof(buf))
		printk(KERN_WARNING DRIVER_NAME ": si470x_get_rds_registers: "
			"return size differs: %d != %zu\n", size, sizeof(buf));
	if (retval < 0)
		printk(KERN_WARNING DRIVER_NAME ": si470x_get_rds_registers: "
			"usb_interrupt_msg returned %d\n", retval);

	if (retval >= 0)
		for (regnr = 0; regnr < RDS_REGISTER_NUM; regnr++)
			radio->registers[STATUSRSSI + regnr] =
				get_unaligned_be16(
				&buf[regnr * RADIO_REGISTER_SIZE + 1]);

	return (retval < 0) ? -EINVAL : 0;
}


/*
 * si470x_set_chan - set the channel
 */
static int si470x_set_chan(struct si470x_device *radio, unsigned short chan)
{
	int retval;
	unsigned long timeout;
	bool timed_out = 0;

	/* start tuning */
	radio->registers[CHANNEL] &= ~CHANNEL_CHAN;
	radio->registers[CHANNEL] |= CHANNEL_TUNE | chan;
	retval = si470x_set_register(radio, CHANNEL);
	if (retval < 0)
		goto done;

	/* wait till tune operation has completed */
	timeout = jiffies + msecs_to_jiffies(tune_timeout);
	do {
		retval = si470x_get_register(radio, STATUSRSSI);
		if (retval < 0)
			goto stop;
		timed_out = time_after(jiffies, timeout);
	} while (((radio->registers[STATUSRSSI] & STATUSRSSI_STC) == 0) &&
		(!timed_out));
	if ((radio->registers[STATUSRSSI] & STATUSRSSI_STC) == 0)
		printk(KERN_WARNING DRIVER_NAME ": tune does not complete\n");
	if (timed_out)
		printk(KERN_WARNING DRIVER_NAME
			": tune timed out after %u ms\n", tune_timeout);

stop:
	/* stop tuning */
	radio->registers[CHANNEL] &= ~CHANNEL_TUNE;
	retval = si470x_set_register(radio, CHANNEL);

done:
	return retval;
}


/*
 * si470x_get_freq - get the frequency
 */
static int si470x_get_freq(struct si470x_device *radio, unsigned int *freq)
{
	unsigned int spacing, band_bottom;
	unsigned short chan;
	int retval;

	/* Spacing (kHz) */
	switch ((radio->registers[SYSCONFIG2] & SYSCONFIG2_SPACE) >> 4) {
	/* 0: 200 kHz (USA, Australia) */
	case 0:
		spacing = 0.200 * FREQ_MUL; break;
	/* 1: 100 kHz (Europe, Japan) */
	case 1:
		spacing = 0.100 * FREQ_MUL; break;
	/* 2:  50 kHz */
	default:
		spacing = 0.050 * FREQ_MUL; break;
	};

	/* Bottom of Band (MHz) */
	switch ((radio->registers[SYSCONFIG2] & SYSCONFIG2_BAND) >> 6) {
	/* 0: 87.5 - 108 MHz (USA, Europe) */
	case 0:
		band_bottom = 87.5 * FREQ_MUL; break;
	/* 1: 76   - 108 MHz (Japan wide band) */
	default:
		band_bottom = 76   * FREQ_MUL; break;
	/* 2: 76   -  90 MHz (Japan) */
	case 2:
		band_bottom = 76   * FREQ_MUL; break;
	};

	/* read channel */
	retval = si470x_get_register(radio, READCHAN);
	chan = radio->registers[READCHAN] & READCHAN_READCHAN;

	/* Frequency (MHz) = Spacing (kHz) x Channel + Bottom of Band (MHz) */
	*freq = chan * spacing + band_bottom;

	return retval;
}


/*
 * si470x_set_freq - set the frequency
 */
static int si470x_set_freq(struct si470x_device *radio, unsigned int freq)
{
	unsigned int spacing, band_bottom;
	unsigned short chan;

	/* Spacing (kHz) */
	switch ((radio->registers[SYSCONFIG2] & SYSCONFIG2_SPACE) >> 4) {
	/* 0: 200 kHz (USA, Australia) */
	case 0:
		spacing = 0.200 * FREQ_MUL; break;
	/* 1: 100 kHz (Europe, Japan) */
	case 1:
		spacing = 0.100 * FREQ_MUL; break;
	/* 2:  50 kHz */
	default:
		spacing = 0.050 * FREQ_MUL; break;
	};

	/* Bottom of Band (MHz) */
	switch ((radio->registers[SYSCONFIG2] & SYSCONFIG2_BAND) >> 6) {
	/* 0: 87.5 - 108 MHz (USA, Europe) */
	case 0:
		band_bottom = 87.5 * FREQ_MUL; break;
	/* 1: 76   - 108 MHz (Japan wide band) */
	default:
		band_bottom = 76   * FREQ_MUL; break;
	/* 2: 76   -  90 MHz (Japan) */
	case 2:
		band_bottom = 76   * FREQ_MUL; break;
	};

	/* Chan = [ Freq (Mhz) - Bottom of Band (MHz) ] / Spacing (kHz) */
	chan = (freq - band_bottom) / spacing;

	return si470x_set_chan(radio, chan);
}


/*
 * si470x_set_seek - set seek
 */
static int si470x_set_seek(struct si470x_device *radio,
		unsigned int wrap_around, unsigned int seek_upward)
{
	int retval = 0;
	unsigned long timeout;
	bool timed_out = 0;

	/* start seeking */
	radio->registers[POWERCFG] |= POWERCFG_SEEK;
	if (wrap_around == 1)
		radio->registers[POWERCFG] &= ~POWERCFG_SKMODE;
	else
		radio->registers[POWERCFG] |= POWERCFG_SKMODE;
	if (seek_upward == 1)
		radio->registers[POWERCFG] |= POWERCFG_SEEKUP;
	else
		radio->registers[POWERCFG] &= ~POWERCFG_SEEKUP;
	retval = si470x_set_register(radio, POWERCFG);
	if (retval < 0)
		goto done;

	/* wait till seek operation has completed */
	timeout = jiffies + msecs_to_jiffies(seek_timeout);
	do {
		retval = si470x_get_register(radio, STATUSRSSI);
		if (retval < 0)
			goto stop;
		timed_out = time_after(jiffies, timeout);
	} while (((radio->registers[STATUSRSSI] & STATUSRSSI_STC) == 0) &&
		(!timed_out));
	if ((radio->registers[STATUSRSSI] & STATUSRSSI_STC) == 0)
		printk(KERN_WARNING DRIVER_NAME ": seek does not complete\n");
	if (radio->registers[STATUSRSSI] & STATUSRSSI_SF)
		printk(KERN_WARNING DRIVER_NAME
			": seek failed / band limit reached\n");
	if (timed_out)
		printk(KERN_WARNING DRIVER_NAME
			": seek timed out after %u ms\n", seek_timeout);

stop:
	/* stop seeking */
	radio->registers[POWERCFG] &= ~POWERCFG_SEEK;
	retval = si470x_set_register(radio, POWERCFG);

done:
	/* try again, if timed out */
	if ((retval == 0) && timed_out)
		retval = -EAGAIN;

	return retval;
}


/*
 * si470x_start - switch on radio
 */
static int si470x_start(struct si470x_device *radio)
{
	int retval;

	/* powercfg */
	radio->registers[POWERCFG] =
		POWERCFG_DMUTE | POWERCFG_ENABLE | POWERCFG_RDSM;
	retval = si470x_set_register(radio, POWERCFG);
	if (retval < 0)
		goto done;

	/* sysconfig 1 */
	radio->registers[SYSCONFIG1] = SYSCONFIG1_DE;
	retval = si470x_set_register(radio, SYSCONFIG1);
	if (retval < 0)
		goto done;

	/* sysconfig 2 */
	radio->registers[SYSCONFIG2] =
		(0x3f  << 8) |				/* SEEKTH */
		((band  << 6) & SYSCONFIG2_BAND)  |	/* BAND */
		((space << 4) & SYSCONFIG2_SPACE) |	/* SPACE */
		15;					/* VOLUME (max) */
	retval = si470x_set_register(radio, SYSCONFIG2);
	if (retval < 0)
		goto done;

	/* reset last channel */
	retval = si470x_set_chan(radio,
		radio->registers[CHANNEL] & CHANNEL_CHAN);

done:
	return retval;
}


/*
 * si470x_stop - switch off radio
 */
static int si470x_stop(struct si470x_device *radio)
{
	int retval;

	/* sysconfig 1 */
	radio->registers[SYSCONFIG1] &= ~SYSCONFIG1_RDS;
	retval = si470x_set_register(radio, SYSCONFIG1);
	if (retval < 0)
		goto done;

	/* powercfg */
	radio->registers[POWERCFG] &= ~POWERCFG_DMUTE;
	/* POWERCFG_ENABLE has to automatically go low */
	radio->registers[POWERCFG] |= POWERCFG_ENABLE |	POWERCFG_DISABLE;
	retval = si470x_set_register(radio, POWERCFG);

done:
	return retval;
}


/*
 * si470x_rds_on - switch on rds reception
 */
static int si470x_rds_on(struct si470x_device *radio)
{
	int retval;

	/* sysconfig 1 */
	mutex_lock(&radio->lock);
	radio->registers[SYSCONFIG1] |= SYSCONFIG1_RDS;
	retval = si470x_set_register(radio, SYSCONFIG1);
	if (retval < 0)
		radio->registers[SYSCONFIG1] &= ~SYSCONFIG1_RDS;
	mutex_unlock(&radio->lock);

	return retval;
}