https://github.com/torvalds/linux
Tip revision: d5226fa6dbae0569ee43ecfc08bdcd6770fc4755 authored by Linus Torvalds on 27 January 2020, 00:23:03 UTC
Linux 5.5
Linux 5.5
Tip revision: d5226fa
radio-terratec.c
// SPDX-License-Identifier: GPL-2.0-only
/* Terratec ActiveRadio ISA Standalone card driver for Linux radio support
* (c) 1999 R. Offermanns (rolf@offermanns.de)
* 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 <hans.verkuil@cisco.com>
* Converted to V4L2 API by Mauro Carvalho Chehab <mchehab@kernel.org>
*/
#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);