radio-gemtek.c

Go to the documentation of this file.

/*
 * GemTek radio card driver
 *
 * Copyright 1998 Jonas Munsin <[email protected]>
 *
 * 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 <[email protected]>
 *    Various bugfixes and enhancements by Russell Kroll <[email protected]>
 *
 * Converted to the radio-isa framework by Hans Verkuil <[email protected]>
 * Converted to V4L2 API by Mauro Carvalho Chehab <[email protected]>
 *
 * Note: this card seems to swap the left and right audio channels!
 *
 * Fully tested with the Keene USB FM Transmitter and the v4l2-compliance tool.
 */

#include <linux/module.h>   /* Modules          */
#include <linux/init.h>     /* Initdata         */
#include <linux/ioport.h>   /* request_region       */
#include <linux/delay.h>    /* udelay           */
#include <linux/videodev2.h>    /* kernel radio structs     */
#include <linux/mutex.h>
#include <linux/io.h>       /* outb, outb_p         */
#include <linux/pnp.h>
#include <linux/slab.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-device.h>
#include "radio-isa.h"

/*
 * Module info.
 */

MODULE_AUTHOR("Jonas Munsin, Pekka Seppänen <[email protected]>");
MODULE_DESCRIPTION("A driver for the GemTek Radio card.");
MODULE_LICENSE("GPL");
MODULE_VERSION("1.0.0");

/*
 * 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

#define GEMTEK_MAX 4

static bool probe = CONFIG_RADIO_GEMTEK_PROBE;
static bool hardmute;
static int io[GEMTEK_MAX] = { [0] = CONFIG_RADIO_GEMTEK_PORT,
                  [1 ... (GEMTEK_MAX - 1)] = -1 };
static int radio_nr[GEMTEK_MAX] = { [0 ... (GEMTEK_MAX - 1)] = -1 };

module_param(probe, bool, 0444);
MODULE_PARM_DESC(probe, "Enable automatic device probing.");

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

module_param_array(io, int, NULL, 0444);
MODULE_PARM_DESC(io, "Force I/O ports 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_array(radio_nr, int, NULL, 0444);
MODULE_PARM_DESC(radio_nr, "Radio device numbers");

/*
 * 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 {
    struct radio_isa_card isa;
    bool 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)

/*
 * 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 *gt)
{
    struct radio_isa_card *isa = &gt->isa;
    int i, bit, q, mute;

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

    outb_p(mute | GEMTEK_CE | GEMTEK_DA | GEMTEK_CK, isa->io);
    udelay(LONG_DELAY);

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

    outb_p(mute | GEMTEK_DA | GEMTEK_CK, isa->io);
    udelay(SHORT_DELAY);
}

/*
 * 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;
}

static struct radio_isa_card *gemtek_alloc(void)
{
    struct gemtek *gt = kzalloc(sizeof(*gt), GFP_KERNEL);

    if (gt)
        gt->muted = true;
    return gt ? &gt->isa : NULL;
}

/*
 * Set FM-frequency.
 */
static int gemtek_s_frequency(struct radio_isa_card *isa, u32 freq)
{
    struct gemtek *gt = container_of(isa, struct gemtek, isa);

    if (hardmute && gt->muted)
        return 0;

    gemtek_bu2614_set(gt, BU2614_PORT, 0);
    gemtek_bu2614_set(gt, BU2614_FMES, 0);
    gemtek_bu2614_set(gt, BU2614_SWIN, 0);  /* FM-mode  */
    gemtek_bu2614_set(gt, BU2614_SWAL, 0);
    gemtek_bu2614_set(gt, BU2614_FMUN, 1);  /* GT bit set   */
    gemtek_bu2614_set(gt, BU2614_TEST, 0);
    gemtek_bu2614_set(gt, BU2614_STDF, GEMTEK_STDF_3_125_KHZ);
    gemtek_bu2614_set(gt, BU2614_FREQ, gemtek_convfreq(freq));
    gemtek_bu2614_transmit(gt);
    return 0;
}

/*
 * Set mute flag.
 */
static int gemtek_s_mute_volume(struct radio_isa_card *isa, bool mute, int vol)
{
    struct gemtek *gt = container_of(isa, struct gemtek, isa);
    int i;

    gt->muted = mute;
    if (hardmute) {
        if (!mute)
            return gemtek_s_frequency(isa, isa->freq);

        /* Turn off PLL, disable data output */
        gemtek_bu2614_set(gt, BU2614_PORT, 0);
        gemtek_bu2614_set(gt, BU2614_FMES, 0);  /* CT bit off   */
        gemtek_bu2614_set(gt, BU2614_SWIN, 0);  /* FM-mode  */
        gemtek_bu2614_set(gt, BU2614_SWAL, 0);
        gemtek_bu2614_set(gt, BU2614_FMUN, 0);  /* GT bit off   */
        gemtek_bu2614_set(gt, BU2614_TEST, 0);
        gemtek_bu2614_set(gt, BU2614_STDF, GEMTEK_PLL_OFF);
        gemtek_bu2614_set(gt, BU2614_FREQ, 0);
        gemtek_bu2614_transmit(gt);
        return 0;
    }

    /* Read bus contents (CE, CK and DA). */
    i = inb_p(isa->io);
    /* Write it back with mute flag set. */
    outb_p((i >> 5) | (mute ? GEMTEK_MT : 0), isa->io);
    udelay(SHORT_DELAY);
    return 0;
}

static u32 gemtek_g_rxsubchans(struct radio_isa_card *isa)
{
    if (inb_p(isa->io) & GEMTEK_NS)
        return V4L2_TUNER_SUB_MONO;
    return V4L2_TUNER_SUB_STEREO;
}

/*
 * Check if requested card acts like GemTek Radio card.
 */
static bool gemtek_probe(struct radio_isa_card *isa, int io)
{
    int i, q;

    q = inb_p(io);  /* 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, io);
        udelay(SHORT_DELAY);

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

static const struct radio_isa_ops gemtek_ops = {
    .alloc = gemtek_alloc,
    .probe = gemtek_probe,
    .s_mute_volume = gemtek_s_mute_volume,
    .s_frequency = gemtek_s_frequency,
    .g_rxsubchans = gemtek_g_rxsubchans,
};

static const int gemtek_ioports[] = { 0x20c, 0x30c, 0x24c, 0x34c, 0x248, 0x28c };

#ifdef CONFIG_PNP
static struct pnp_device_id gemtek_pnp_devices[] = {
    /* AOpen FX-3D/Pro Radio */
    {.id = "ADS7183", .driver_data = 0},
    {.id = ""}
};

MODULE_DEVICE_TABLE(pnp, gemtek_pnp_devices);
#endif

static struct radio_isa_driver gemtek_driver = {
    .driver = {
        .match      = radio_isa_match,
        .probe      = radio_isa_probe,
        .remove     = radio_isa_remove,
        .driver     = {
            .name   = "radio-gemtek",
        },
    },
#ifdef CONFIG_PNP
    .pnp_driver = {
        .name       = "radio-gemtek",
        .id_table   = gemtek_pnp_devices,
        .probe      = radio_isa_pnp_probe,
        .remove     = radio_isa_pnp_remove,
    },
#endif
    .io_params = io,
    .radio_nr_params = radio_nr,
    .io_ports = gemtek_ioports,
    .num_of_io_ports = ARRAY_SIZE(gemtek_ioports),
    .region_size = 1,
    .card = "GemTek Radio",
    .ops = &gemtek_ops,
    .has_stereo = true,
};

static int __init gemtek_init(void)
{
    gemtek_driver.probe = probe;
#ifdef CONFIG_PNP
    pnp_register_driver(&gemtek_driver.pnp_driver);
#endif
    return isa_register_driver(&gemtek_driver.driver, GEMTEK_MAX);
}

static void __exit gemtek_exit(void)
{
    hardmute = 1;   /* Turn off PLL */
#ifdef CONFIG_PNP
    pnp_unregister_driver(&gemtek_driver.pnp_driver);
#endif
    isa_unregister_driver(&gemtek_driver.driver);
}

module_init(gemtek_init);
module_exit(gemtek_exit);