/*
 * AimsLab RadioTrack (aka RadioVeveal) driver
 *
 * Copyright 1997 M. Kirkwood
 *
 * Converted to the radio-isa framework by Hans Verkuil <hans.verkuil@cisco.com>
 * Converted to V4L2 API by Mauro Carvalho Chehab <mchehab@kernel.org>
 * Converted to new API by Alan Cox <alan@lxorguk.ukuu.org.uk>
 * Various bugfixes and enhancements by Russell Kroll <rkroll@exploits.org>
 *
 * Notes on the hardware (reverse engineered from other peoples'
 * reverse engineering of AIMS' code :-)
 *
 *  Frequency control is done digitally -- ie out(port,encodefreq(95.8));
 *
 *  The signal strength query is unsurprisingly inaccurate.  And it seems
 *  to indicate that (on my card, at least) the frequency setting isn't
 *  too great.  (I have to tune up .025MHz from what the freq should be
 *  to get a report that the thing is tuned.)
 *
 *  Volume control is (ugh) analogue:
 *   out(port, start_increasing_volume);
 *   wait(a_wee_while);
 *   out(port, stop_changing_the_volume);
 *
 * 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>        /* msleep                       */
#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"
#include "lm7000.h"

MODULE_AUTHOR("M. Kirkwood");
MODULE_DESCRIPTION("A driver for the RadioTrack/RadioReveal radio card.");
MODULE_LICENSE("GPL");
MODULE_VERSION("1.0.0");

#ifndef CONFIG_RADIO_RTRACK_PORT
#define CONFIG_RADIO_RTRACK_PORT -1
#endif

#define RTRACK_MAX 2

static int io[RTRACK_MAX] = { [0] = CONFIG_RADIO_RTRACK_PORT,
                              [1 ... (RTRACK_MAX - 1)] = -1 };
static int radio_nr[RTRACK_MAX] = { [0 ... (RTRACK_MAX - 1)] = -1 };

module_param_array(io, int, NULL, 0444);
MODULE_PARM_DESC(io, "I/O addresses of the RadioTrack card (0x20f or 0x30f)");
module_param_array(radio_nr, int, NULL, 0444);
MODULE_PARM_DESC(radio_nr, "Radio device numbers");

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

static struct radio_isa_card *rtrack_alloc(void)
{
        struct rtrack *rt = kzalloc(sizeof(struct rtrack), GFP_KERNEL);

        if (rt)
                rt->curvol = 0xff;
        return rt ? &rt->isa : NULL;
}

#define AIMS_BIT_TUN_CE         (1 << 0)
#define AIMS_BIT_TUN_CLK        (1 << 1)
#define AIMS_BIT_TUN_DATA       (1 << 2)
#define AIMS_BIT_VOL_CE         (1 << 3)
#define AIMS_BIT_TUN_STRQ       (1 << 4)
/* bit 5 is not connected */
#define AIMS_BIT_VOL_UP         (1 << 6)        /* active low */
#define AIMS_BIT_VOL_DN         (1 << 7)        /* active low */

static void rtrack_set_pins(void *handle, u8 pins)
{
        struct radio_isa_card *isa = handle;
        struct rtrack *rt = container_of(isa, struct rtrack, isa);
        u8 bits = AIMS_BIT_VOL_DN | AIMS_BIT_VOL_UP | AIMS_BIT_TUN_STRQ;

        if (!v4l2_ctrl_g_ctrl(rt->isa.mute))
                bits |= AIMS_BIT_VOL_CE;

        if (pins & LM7000_DATA)
                bits |= AIMS_BIT_TUN_DATA;
        if (pins & LM7000_CLK)
                bits |= AIMS_BIT_TUN_CLK;
        if (pins & LM7000_CE)
                bits |= AIMS_BIT_TUN_CE;

        outb_p(bits, rt->isa.io);
}

static int rtrack_s_frequency(struct radio_isa_card *isa, u32 freq)
{
        lm7000_set_freq(freq, isa, rtrack_set_pins);

        return 0;
}

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

static int rtrack_s_mute_volume(struct radio_isa_card *isa, bool mute, int vol)
{
        struct rtrack *rt = container_of(isa, struct rtrack, isa);
        int curvol = rt->curvol;

        if (mute) {
                outb(0xd0, isa->io);    /* volume steady + sigstr + off */
                return 0;
        }
        if (vol == 0) {                 /* volume = 0 means mute the card */
                outb(0x48, isa->io);    /* volume down but still "on"   */
                msleep(curvol * 3);     /* make sure it's totally down  */
        } else if (curvol < vol) {
                outb(0x98, isa->io);    /* volume up + sigstr + on      */
                for (; curvol < vol; curvol++)
                        mdelay(3);
        } else if (curvol > vol) {
                outb(0x58, isa->io);    /* volume down + sigstr + on    */
                for (; curvol > vol; curvol--)
                        mdelay(3);
        }
        outb(0xd8, isa->io);            /* volume steady + sigstr + on  */
        rt->curvol = vol;
        return 0;
}

/* Mute card - prevents noisy bootups */
static int rtrack_initialize(struct radio_isa_card *isa)
{
        /* this ensures that the volume is all the way up  */
        outb(0x90, isa->io);    /* volume up but still "on"     */
        msleep(3000);           /* make sure it's totally up    */
        outb(0xc0, isa->io);    /* steady volume, mute card     */
        return 0;
}

static const struct radio_isa_ops rtrack_ops = {
        .alloc = rtrack_alloc,
        .init = rtrack_initialize,
        .s_mute_volume = rtrack_s_mute_volume,
        .s_frequency = rtrack_s_frequency,
        .g_signal = rtrack_g_signal,
};

static const int rtrack_ioports[] = { 0x20f, 0x30f };

static struct radio_isa_driver rtrack_driver = {
        .driver = {
                .match          = radio_isa_match,
                .probe          = radio_isa_probe,
                .remove         = radio_isa_remove,
                .driver         = {
                        .name   = "radio-aimslab",
                },
        },
        .io_params = io,
        .radio_nr_params = radio_nr,
        .io_ports = rtrack_ioports,
        .num_of_io_ports = ARRAY_SIZE(rtrack_ioports),
        .region_size = 2,
        .card = "AIMSlab RadioTrack/RadioReveal",
        .ops = &rtrack_ops,
        .has_stereo = true,
        .max_volume = 0xff,
};

static int __init rtrack_init(void)
{
        return isa_register_driver(&rtrack_driver.driver, RTRACK_MAX);
}

static void __exit rtrack_exit(void)
{
        isa_unregister_driver(&rtrack_driver.driver);
}

module_init(rtrack_init);
module_exit(rtrack_exit);