radio-terratec.c

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/* Terratec ActiveRadio ISA Standalone card driver for Linux radio support
 * (c) 1999 R. Offermanns ([email protected])
 * based on the aimslab radio driver from M. Kirkwood
 * many thanks to Michael Becker and Friedhelm Birth (from TerraTec)
 *
 *
 * History:
 * 1999-05-21   First preview release
 *
 *  Notes on the hardware:
 *  There are two "main" chips on the card:
 *  - Philips OM5610 (http://www-us.semiconductors.philips.com/acrobat/datasheets/OM5610_2.pdf)
 *  - Philips SAA6588 (http://www-us.semiconductors.philips.com/acrobat/datasheets/SAA6588_1.pdf)
 *  (you can get the datasheet at the above links)
 *
 *  Frequency control is done digitally -- ie out(port,encodefreq(95.8));
 *  Volume Control is done digitally
 *
 * Converted to the radio-isa framework by Hans Verkuil <[email protected]>
 * Converted to V4L2 API by Mauro Carvalho Chehab <[email protected]>
 */

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

MODULE_AUTHOR("R. Offermans & others");
MODULE_DESCRIPTION("A driver for the TerraTec ActiveRadio Standalone radio card.");
MODULE_LICENSE("GPL");
MODULE_VERSION("0.1.99");

/* Note: there seems to be only one possible port (0x590), but without
   hardware this is hard to verify. For now, this is the only one we will
   support. */
static int io = 0x590;
static int radio_nr = -1;

module_param(radio_nr, int, 0444);
MODULE_PARM_DESC(radio_nr, "Radio device number");

#define WRT_DIS     0x00
#define CLK_OFF     0x00
#define IIC_DATA    0x01
#define IIC_CLK     0x02
#define DATA        0x04
#define CLK_ON      0x08
#define WRT_EN      0x10

static struct radio_isa_card *terratec_alloc(void)
{
    return kzalloc(sizeof(struct radio_isa_card), GFP_KERNEL);
}

static int terratec_s_mute_volume(struct radio_isa_card *isa, bool mute, int vol)
{
    int i;

    if (mute)
        vol = 0;
    vol = vol + (vol * 32); /* change both channels */
    for (i = 0; i < 8; i++) {
        if (vol & (0x80 >> i))
            outb(0x80, isa->io + 1);
        else
            outb(0x00, isa->io + 1);
    }
    return 0;
}


/* this is the worst part in this driver */
/* many more or less strange things are going on here, but hey, it works :) */

static int terratec_s_frequency(struct radio_isa_card *isa, u32 freq)
{
    int i;
    int p;
    int temp;
    long rest;
    unsigned char buffer[25];       /* we have to bit shift 25 registers */

    freq = freq / 160;          /* convert the freq. to a nice to handle value */
    memset(buffer, 0, sizeof(buffer));

    rest = freq * 10 + 10700;   /* I once had understood what is going on here */
                    /* maybe some wise guy (friedhelm?) can comment this stuff */
    i = 13;
    p = 10;
    temp = 102400;
    while (rest != 0) {
        if (rest % temp  == rest)
            buffer[i] = 0;
        else {
            buffer[i] = 1;
            rest = rest - temp;
        }
        i--;
        p--;
        temp = temp / 2;
    }

    for (i = 24; i > -1; i--) { /* bit shift the values to the radiocard */
        if (buffer[i] == 1) {
            outb(WRT_EN | DATA, isa->io);
            outb(WRT_EN | DATA | CLK_ON, isa->io);
            outb(WRT_EN | DATA, isa->io);
        } else {
            outb(WRT_EN | 0x00, isa->io);
            outb(WRT_EN | 0x00 | CLK_ON, isa->io);
        }
    }
    outb(0x00, isa->io);
    return 0;
}

static u32 terratec_g_signal(struct radio_isa_card *isa)
{
    /* bit set = no signal present  */
    return (inb(isa->io) & 2) ? 0 : 0xffff;
}

static const struct radio_isa_ops terratec_ops = {
    .alloc = terratec_alloc,
    .s_mute_volume = terratec_s_mute_volume,
    .s_frequency = terratec_s_frequency,
    .g_signal = terratec_g_signal,
};

static const int terratec_ioports[] = { 0x590 };

static struct radio_isa_driver terratec_driver = {
    .driver = {
        .match      = radio_isa_match,
        .probe      = radio_isa_probe,
        .remove     = radio_isa_remove,
        .driver     = {
            .name   = "radio-terratec",
        },
    },
    .io_params = &io,
    .radio_nr_params = &radio_nr,
    .io_ports = terratec_ioports,
    .num_of_io_ports = ARRAY_SIZE(terratec_ioports),
    .region_size = 2,
    .card = "TerraTec ActiveRadio",
    .ops = &terratec_ops,
    .has_stereo = true,
    .max_volume = 10,
};

static int __init terratec_init(void)
{
    return isa_register_driver(&terratec_driver.driver, 1);
}

static void __exit terratec_exit(void)
{
    isa_unregister_driver(&terratec_driver.driver);
}

module_init(terratec_init);
module_exit(terratec_exit);