radio-aztech.c

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/*
 * radio-aztech.c - Aztech radio card driver
 *
 * Converted to the radio-isa framework by Hans Verkuil <[email protected]>
 * Converted to V4L2 API by Mauro Carvalho Chehab <[email protected]>
 * Adapted to support the Video for Linux API by
 * Russell Kroll <[email protected]>.  Based on original tuner code by:
 *
 * Quay Ly
 * Donald Song
 * Jason Lewis      ([email protected])
 * Scott McGrath    ([email protected])
 * William McGrath  ([email protected])
 *
 * 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/io.h>       /* outb, outb_p         */
#include <linux/slab.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-ctrls.h>
#include "radio-isa.h"

MODULE_AUTHOR("Russell Kroll, Quay Lu, Donald Song, Jason Lewis, Scott McGrath, William McGrath");
MODULE_DESCRIPTION("A driver for the Aztech radio card.");
MODULE_LICENSE("GPL");
MODULE_VERSION("1.0.0");

/* acceptable ports: 0x350 (JP3 shorted), 0x358 (JP3 open) */
#ifndef CONFIG_RADIO_AZTECH_PORT
#define CONFIG_RADIO_AZTECH_PORT -1
#endif

#define AZTECH_MAX 2

static int io[AZTECH_MAX] = { [0] = CONFIG_RADIO_AZTECH_PORT,
                  [1 ... (AZTECH_MAX - 1)] = -1 };
static int radio_nr[AZTECH_MAX] = { [0 ... (AZTECH_MAX - 1)] = -1 };
static const int radio_wait_time = 1000;

module_param_array(io, int, NULL, 0444);
MODULE_PARM_DESC(io, "I/O addresses of the Aztech card (0x350 or 0x358)");
module_param_array(radio_nr, int, NULL, 0444);
MODULE_PARM_DESC(radio_nr, "Radio device numbers");

struct aztech {
    struct radio_isa_card isa;
    int curvol;
};

static void send_0_byte(struct aztech *az)
{
    udelay(radio_wait_time);
    outb_p(2 + az->curvol, az->isa.io);
    outb_p(64 + 2 + az->curvol, az->isa.io);
}

static void send_1_byte(struct aztech *az)
{
    udelay(radio_wait_time);
    outb_p(128 + 2 + az->curvol, az->isa.io);
    outb_p(128 + 64 + 2 + az->curvol, az->isa.io);
}

static struct radio_isa_card *aztech_alloc(void)
{
    struct aztech *az = kzalloc(sizeof(*az), GFP_KERNEL);

    return az ? &az->isa : NULL;
}

static int aztech_s_frequency(struct radio_isa_card *isa, u32 freq)
{
    struct aztech *az = container_of(isa, struct aztech, isa);
    int  i;

    freq += 171200;         /* Add 10.7 MHz IF      */
    freq /= 800;            /* Convert to 50 kHz units  */

    send_0_byte(az);        /*  0: LSB of frequency       */

    for (i = 0; i < 13; i++)    /*   : frequency bits (1-13)  */
        if (freq & (1 << i))
            send_1_byte(az);
        else
            send_0_byte(az);

    send_0_byte(az);        /* 14: test bit - always 0    */
    send_0_byte(az);        /* 15: test bit - always 0    */
    send_0_byte(az);        /* 16: band data 0 - always 0 */
    if (isa->stereo)        /* 17: stereo (1 to enable)   */
        send_1_byte(az);
    else
        send_0_byte(az);

    send_1_byte(az);        /* 18: band data 1 - unknown  */
    send_0_byte(az);        /* 19: time base - always 0   */
    send_0_byte(az);        /* 20: spacing (0 = 25 kHz)   */
    send_1_byte(az);        /* 21: spacing (1 = 25 kHz)   */
    send_0_byte(az);        /* 22: spacing (0 = 25 kHz)   */
    send_1_byte(az);        /* 23: AM/FM (FM = 1, always) */

    /* latch frequency */

    udelay(radio_wait_time);
    outb_p(128 + 64 + az->curvol, az->isa.io);

    return 0;
}

/* thanks to Michael Dwyer for giving me a dose of clues in
 * the signal strength department..
 *
 * This card has a stereo bit - bit 0 set = mono, not set = stereo
 */
static u32 aztech_g_rxsubchans(struct radio_isa_card *isa)
{
    if (inb(isa->io) & 1)
        return V4L2_TUNER_SUB_MONO;
    return V4L2_TUNER_SUB_STEREO;
}

static int aztech_s_stereo(struct radio_isa_card *isa, bool stereo)
{
    return aztech_s_frequency(isa, isa->freq);
}

static int aztech_s_mute_volume(struct radio_isa_card *isa, bool mute, int vol)
{
    struct aztech *az = container_of(isa, struct aztech, isa);

    if (mute)
        vol = 0;
    az->curvol = (vol & 1) + ((vol & 2) << 1);
    outb(az->curvol, isa->io);
    return 0;
}

static const struct radio_isa_ops aztech_ops = {
    .alloc = aztech_alloc,
    .s_mute_volume = aztech_s_mute_volume,
    .s_frequency = aztech_s_frequency,
    .s_stereo = aztech_s_stereo,
    .g_rxsubchans = aztech_g_rxsubchans,
};

static const int aztech_ioports[] = { 0x350, 0x358 };

static struct radio_isa_driver aztech_driver = {
    .driver = {
        .match      = radio_isa_match,
        .probe      = radio_isa_probe,
        .remove     = radio_isa_remove,
        .driver     = {
            .name   = "radio-aztech",
        },
    },
    .io_params = io,
    .radio_nr_params = radio_nr,
    .io_ports = aztech_ioports,
    .num_of_io_ports = ARRAY_SIZE(aztech_ioports),
    .region_size = 2,
    .card = "Aztech Radio",
    .ops = &aztech_ops,
    .has_stereo = true,
    .max_volume = 3,
};

static int __init aztech_init(void)
{
    return isa_register_driver(&aztech_driver.driver, AZTECH_MAX);
}

static void __exit aztech_exit(void)
{
    isa_unregister_driver(&aztech_driver.driver);
}

module_init(aztech_init);
module_exit(aztech_exit);