radio-gemtek.c

trident tm5600的linux驱动

/* GemTek radio card driver for Linux (C) 1998 Jonas Munsin <[e-mail]>
 *
 * GemTek hasn't released any specs on the card, so the protocol had to
 * be reverse engineered with dosemu.
 *
 * Besides the protocol changes, this is mostly a copy of:
 *
 *    RadioTrack II driver for Linux radio support (C) 1998 Ben Pfaff
 *
 *    Based on RadioTrack I/RadioReveal (C) 1997 M. Kirkwood
 *    Converted to new API by Alan Cox <[e-mail]>
 *    Various bugfixes and enhancements by Russell Kroll <[e-mail]>
 *
 * TODO: Allow for more than one of these foolish entities :-)
 *
 * Converted to V4L2 API by Mauro Carvalho Chehab <[e-mail]>
 */

#include <linux/module.h>	/* Modules 			*/
#include <linux/init.h>		/* Initdata			*/
#include <linux/ioport.h>	/* request_region		*/
#include <linux/delay.h>	/* udelay			*/
#include <asm/io.h>		/* outb, outb_p			*/
#include <asm/uaccess.h>	/* copy to/from user		*/
#include "compat.h"
#include <linux/videodev2.h>	/* kernel radio structs		*/
#include <media/v4l2-ioctl.h>
#include <media/v4l2-common.h>
#include <linux/spinlock.h>

#include <linux/version.h>	/* for KERNEL_VERSION MACRO	*/
#define RADIO_VERSION KERNEL_VERSION(0,0,3)
#define RADIO_BANNER "GemTek Radio card driver: v0.0.3"

/*
 * Module info.
 */

MODULE_AUTHOR("Jonas Munsin, Pekka Sepp鋘en <[e-mail]>");
MODULE_DESCRIPTION("A driver for the GemTek Radio card.");
MODULE_LICENSE("GPL");

/*
 * Module params.
 */

#ifndef CONFIG_RADIO_GEMTEK_PORT
#define CONFIG_RADIO_GEMTEK_PORT -1
#endif
#ifndef CONFIG_RADIO_GEMTEK_PROBE
#define CONFIG_RADIO_GEMTEK_PROBE 1
#endif

static int io		= CONFIG_RADIO_GEMTEK_PORT;
static int probe	= CONFIG_RADIO_GEMTEK_PROBE;
static int hardmute;
static int shutdown	= 1;
static int keepmuted	= 1;
static int initmute	= 1;
static int radio_nr	= -1;
static unsigned long in_use;

module_param(io, int, 0444);
MODULE_PARM_DESC(io, "Force I/O port for the GemTek Radio card if automatic "
	 "probing is disabled or fails. The most common I/O ports are: 0x20c "
	 "0x30c, 0x24c or 0x34c (0x20c, 0x248 and 0x28c have been reported to "
	 "work for the combined sound/radiocard).");

module_param(probe, bool, 0444);
MODULE_PARM_DESC(probe, "Enable automatic device probing. Note: only the most "
	"common I/O ports used by the card are probed.");

module_param(hardmute, bool, 0644);
MODULE_PARM_DESC(hardmute, "Enable `hard muting' by shutting down PLL, may "
	 "reduce static noise.");

module_param(shutdown, bool, 0644);
MODULE_PARM_DESC(shutdown, "Enable shutting down PLL and muting line when "
	 "module is unloaded.");

module_param(keepmuted, bool, 0644);
MODULE_PARM_DESC(keepmuted, "Keep card muted even when frequency is changed.");

module_param(initmute, bool, 0444);
MODULE_PARM_DESC(initmute, "Mute card when module is loaded.");

module_param(radio_nr, int, 0444);

/*
 * Functions for controlling the card.
 */
#define GEMTEK_LOWFREQ	(87*16000)
#define GEMTEK_HIGHFREQ	(108*16000)

/*
 * Frequency calculation constants.  Intermediate frequency 10.52 MHz (nominal
 * value 10.7 MHz), reference divisor 6.39 kHz (nominal 6.25 kHz).
 */
#define FSCALE		8
#define IF_OFFSET	((unsigned int)(10.52 * 16000 * (1<<FSCALE)))
#define REF_FREQ	((unsigned int)(6.39 * 16 * (1<<FSCALE)))

#define GEMTEK_CK		0x01	/* Clock signal			*/
#define GEMTEK_DA		0x02	/* Serial data			*/
#define GEMTEK_CE		0x04	/* Chip enable			*/
#define GEMTEK_NS		0x08	/* No signal			*/
#define GEMTEK_MT		0x10	/* Line mute			*/
#define GEMTEK_STDF_3_125_KHZ	0x01	/* Standard frequency 3.125 kHz	*/
#define GEMTEK_PLL_OFF		0x07	/* PLL off			*/

#define BU2614_BUS_SIZE	32	/* BU2614 / BU2614FS bus size		*/

#define SHORT_DELAY 5		/* usec */
#define LONG_DELAY 75		/* usec */

struct gemtek_device {
	unsigned long lastfreq;
	int muted;
	u32 bu2614data;
};

#define BU2614_FREQ_BITS 	16 /* D0..D15, Frequency data		*/
#define BU2614_PORT_BITS	3 /* P0..P2, Output port control data	*/
#define BU2614_VOID_BITS	4 /* unused 				*/
#define BU2614_FMES_BITS	1 /* CT, Frequency measurement beginning data */
#define BU2614_STDF_BITS	3 /* R0..R2, Standard frequency data	*/
#define BU2614_SWIN_BITS	1 /* S, Switch between FMIN / AMIN	*/
#define BU2614_SWAL_BITS        1 /* PS, Swallow counter division (AMIN only)*/
#define BU2614_VOID2_BITS	1 /* unused				*/
#define BU2614_FMUN_BITS	1 /* GT, Frequency measurement time & unlock */
#define BU2614_TEST_BITS	1 /* TS, Test data is input		*/

#define BU2614_FREQ_SHIFT 	0
#define BU2614_PORT_SHIFT	(BU2614_FREQ_BITS + BU2614_FREQ_SHIFT)
#define BU2614_VOID_SHIFT	(BU2614_PORT_BITS + BU2614_PORT_SHIFT)
#define BU2614_FMES_SHIFT	(BU2614_VOID_BITS + BU2614_VOID_SHIFT)
#define BU2614_STDF_SHIFT	(BU2614_FMES_BITS + BU2614_FMES_SHIFT)
#define BU2614_SWIN_SHIFT	(BU2614_STDF_BITS + BU2614_STDF_SHIFT)
#define BU2614_SWAL_SHIFT	(BU2614_SWIN_BITS + BU2614_SWIN_SHIFT)
#define BU2614_VOID2_SHIFT	(BU2614_SWAL_BITS + BU2614_SWAL_SHIFT)
#define BU2614_FMUN_SHIFT	(BU2614_VOID2_BITS + BU2614_VOID2_SHIFT)
#define BU2614_TEST_SHIFT	(BU2614_FMUN_BITS + BU2614_FMUN_SHIFT)

#define MKMASK(field)	(((1<<BU2614_##field##_BITS) - 1) << \
			BU2614_##field##_SHIFT)
#define BU2614_PORT_MASK	MKMASK(PORT)
#define BU2614_FREQ_MASK	MKMASK(FREQ)
#define BU2614_VOID_MASK	MKMASK(VOID)
#define BU2614_FMES_MASK	MKMASK(FMES)
#define BU2614_STDF_MASK	MKMASK(STDF)
#define BU2614_SWIN_MASK	MKMASK(SWIN)
#define BU2614_SWAL_MASK	MKMASK(SWAL)
#define BU2614_VOID2_MASK	MKMASK(VOID2)
#define BU2614_FMUN_MASK	MKMASK(FMUN)
#define BU2614_TEST_MASK	MKMASK(TEST)

static struct gemtek_device gemtek_unit;

static spinlock_t lock;

/*
 * Set data which will be sent to BU2614FS.
 */
#define gemtek_bu2614_set(dev, field, data) ((dev)->bu2614data = \
	((dev)->bu2614data & ~field##_MASK) | ((data) << field##_SHIFT))

/*
 * Transmit settings to BU2614FS over GemTek IC.
 */
static void gemtek_bu2614_transmit(struct gemtek_device *dev)
{
	int i, bit, q, mute;

	spin_lock(&lock);

	mute = dev->muted ? GEMTEK_MT : 0x00;

	outb_p(mute | GEMTEK_DA | GEMTEK_CK, io);
	udelay(SHORT_DELAY);
	outb_p(mute | GEMTEK_CE | GEMTEK_DA | GEMTEK_CK, io);
	udelay(LONG_DELAY);

	for (i = 0, q = dev->bu2614data; i < 32; i++, q >>= 1) {
	    bit = (q & 1) ? GEMTEK_DA : 0;
	    outb_p(mute | GEMTEK_CE | bit, io);
	    udelay(SHORT_DELAY);
	    outb_p(mute | GEMTEK_CE | bit | GEMTEK_CK, io);
	    udelay(SHORT_DELAY);
	}

	outb_p(mute | GEMTEK_DA | GEMTEK_CK, io);
	udelay(SHORT_DELAY);
	outb_p(mute | GEMTEK_CE | GEMTEK_DA | GEMTEK_CK, io);
	udelay(LONG_DELAY);

	spin_unlock(&lock);
}

/*
 * Calculate divisor from FM-frequency for BU2614FS (3.125 KHz STDF expected).
 */
static unsigned long gemtek_convfreq(unsigned long freq)
{
	return ((freq<<FSCALE) + IF_OFFSET + REF_FREQ/2) / REF_FREQ;
}

/*
 * Set FM-frequency.
 */
static void gemtek_setfreq(struct gemtek_device *dev, unsigned long freq)
{

	if (keepmuted && hardmute && dev->muted)
		return;

	if (freq < GEMTEK_LOWFREQ)
		freq = GEMTEK_LOWFREQ;
	else if (freq > GEMTEK_HIGHFREQ)
		freq = GEMTEK_HIGHFREQ;

	dev->lastfreq = freq;
	dev->muted = 0;

	gemtek_bu2614_set(dev, BU2614_PORT, 0);
	gemtek_bu2614_set(dev, BU2614_FMES, 0);
	gemtek_bu2614_set(dev, BU2614_SWIN, 0);	/* FM-mode	*/
	gemtek_bu2614_set(dev, BU2614_SWAL, 0);
	gemtek_bu2614_set(dev, BU2614_FMUN, 1);	/* GT bit set	*/
	gemtek_bu2614_set(dev, BU2614_TEST, 0);

	gemtek_bu2614_set(dev, BU2614_STDF, GEMTEK_STDF_3_125_KHZ);
	gemtek_bu2614_set(dev, BU2614_FREQ, gemtek_convfreq(freq));

	gemtek_bu2614_transmit(dev);
}

/*
 * Set mute flag.
 */
static void gemtek_mute(struct gemtek_device *dev)
{
	int i;
	dev->muted = 1;

	if (hardmute) {
		/* Turn off PLL, disable data output */
		gemtek_bu2614_set(dev, BU2614_PORT, 0);
		gemtek_bu2614_set(dev, BU2614_FMES, 0);	/* CT bit off	*/
		gemtek_bu2614_set(dev, BU2614_SWIN, 0);	/* FM-mode	*/
		gemtek_bu2614_set(dev, BU2614_SWAL, 0);
		gemtek_bu2614_set(dev, BU2614_FMUN, 0);	/* GT bit off	*/
		gemtek_bu2614_set(dev, BU2614_TEST, 0);
		gemtek_bu2614_set(dev, BU2614_STDF, GEMTEK_PLL_OFF);
		gemtek_bu2614_set(dev, BU2614_FREQ, 0);
		gemtek_bu2614_transmit(dev);
	} else {
		spin_lock(&lock);

		/* Read bus contents (CE, CK and DA). */
		i = inb_p(io);
		/* Write it back with mute flag set. */
		outb_p((i >> 5) | GEMTEK_MT, io);
		udelay(SHORT_DELAY);

		spin_unlock(&lock);
	}
}

/*
 * Unset mute flag.
 */
static void gemtek_unmute(struct gemtek_device *dev)
{
	int i;
	dev->muted = 0;

	if (hardmute) {
		/* Turn PLL back on. */
		gemtek_setfreq(dev, dev->lastfreq);
	} else {
		spin_lock(&lock);

		i = inb_p(io);
		outb_p(i >> 5, io);
		udelay(SHORT_DELAY);

		spin_unlock(&lock);
	}
}

/*
 * Get signal strength (= stereo status).
 */
static inline int gemtek_getsigstr(void)
{
	return inb_p(io) & GEMTEK_NS ? 0 : 1;
}

/*
 * Check if requested card acts like GemTek Radio card.
 */
static int gemtek_verify(int port)
{
	static int verified = -1;
	int i, q;

	if (verified == port)
		return 1;

	spin_lock(&lock);

	q = inb_p(port);	/* Read bus contents before probing. */
	/* Try to turn on CE, CK and DA respectively and check if card responds
	   properly. */
	for (i = 0; i < 3; ++i) {
		outb_p(1 << i, port);
		udelay(SHORT_DELAY);

		if ((inb_p(port) & (~GEMTEK_NS)) != (0x17 | (1 << (i + 5)))) {
			spin_unlock(&lock);
			return 0;
		}
	}
	outb_p(q >> 5, port);	/* Write bus contents back. */
	udelay(SHORT_DELAY);

	spin_unlock(&lock);
	verified = port;