linux/sound/oss/uart6850.c
David Howells 232b0b0829 Annotate hardware config module parameters in sound/oss/
When the kernel is running in secure boot mode, we lock down the kernel to
prevent userspace from modifying the running kernel image.  Whilst this
includes prohibiting access to things like /dev/mem, it must also prevent
access by means of configuring driver modules in such a way as to cause a
device to access or modify the kernel image.

To this end, annotate module_param* statements that refer to hardware
configuration and indicate for future reference what type of parameter they
specify.  The parameter parser in the core sees this information and can
skip such parameters with an error message if the kernel is locked down.
The module initialisation then runs as normal, but just sees whatever the
default values for those parameters is.

Note that we do still need to do the module initialisation because some
drivers have viable defaults set in case parameters aren't specified and
some drivers support automatic configuration (e.g. PNP or PCI) in addition
to manually coded parameters.

This patch annotates drivers in sound/oss/.

Suggested-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jaroslav Kysela <perex@perex.cz>
cc: Takashi Iwai <tiwai@suse.com>
cc: Andrew Veliath <andrewtv@usa.net>
cc: alsa-devel@alsa-project.org
2017-04-20 12:02:32 +01:00

362 lines
7.1 KiB
C

/*
* sound/oss/uart6850.c
*
*
* Copyright (C) by Hannu Savolainen 1993-1997
*
* OSS/Free for Linux is distributed under the GNU GENERAL PUBLIC LICENSE (GPL)
* Version 2 (June 1991). See the "COPYING" file distributed with this software
* for more info.
* Extended by Alan Cox for Red Hat Software. Now a loadable MIDI driver.
* 28/4/97 - (C) Copyright Alan Cox. Released under the GPL version 2.
*
* Alan Cox: Updated for new modular code. Removed snd_* irq handling. Now
* uses native linux resources
* Christoph Hellwig: Adapted to module_init/module_exit
* Jeff Garzik: Made it work again, in theory
* FIXME: If the request_irq() succeeds, the probe succeeds. Ug.
*
* Status: Testing required (no shit -jgarzik)
*
*
*/
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/spinlock.h>
/* Mon Nov 22 22:38:35 MET 1993 marco@driq.home.usn.nl:
* added 6850 support, used with COVOX SoundMaster II and custom cards.
*/
#include "sound_config.h"
static int uart6850_base = 0x330;
static int *uart6850_osp;
#define DATAPORT (uart6850_base)
#define COMDPORT (uart6850_base+1)
#define STATPORT (uart6850_base+1)
static int uart6850_status(void)
{
return inb(STATPORT);
}
#define input_avail() (uart6850_status()&INPUT_AVAIL)
#define output_ready() (uart6850_status()&OUTPUT_READY)
static void uart6850_cmd(unsigned char cmd)
{
outb(cmd, COMDPORT);
}
static int uart6850_read(void)
{
return inb(DATAPORT);
}
static void uart6850_write(unsigned char byte)
{
outb(byte, DATAPORT);
}
#define OUTPUT_READY 0x02 /* Mask for data ready Bit */
#define INPUT_AVAIL 0x01 /* Mask for Data Send Ready Bit */
#define UART_RESET 0x95
#define UART_MODE_ON 0x03
static int uart6850_opened;
static int uart6850_irq;
static int uart6850_detected;
static int my_dev;
static DEFINE_SPINLOCK(lock);
static void (*midi_input_intr) (int dev, unsigned char data);
static void poll_uart6850(unsigned long dummy);
static DEFINE_TIMER(uart6850_timer, poll_uart6850, 0, 0);
static void uart6850_input_loop(void)
{
int count = 10;
while (count)
{
/*
* Not timed out
*/
if (input_avail())
{
unsigned char c = uart6850_read();
count = 100;
if (uart6850_opened & OPEN_READ)
midi_input_intr(my_dev, c);
}
else
{
while (!input_avail() && count)
count--;
}
}
}
static irqreturn_t m6850intr(int irq, void *dev_id)
{
if (input_avail())
uart6850_input_loop();
return IRQ_HANDLED;
}
/*
* It looks like there is no input interrupts in the UART mode. Let's try
* polling.
*/
static void poll_uart6850(unsigned long dummy)
{
unsigned long flags;
if (!(uart6850_opened & OPEN_READ))
return; /* Device has been closed */
spin_lock_irqsave(&lock,flags);
if (input_avail())
uart6850_input_loop();
uart6850_timer.expires = 1 + jiffies;
add_timer(&uart6850_timer);
/*
* Come back later
*/
spin_unlock_irqrestore(&lock,flags);
}
static int uart6850_open(int dev, int mode,
void (*input) (int dev, unsigned char data),
void (*output) (int dev)
)
{
if (uart6850_opened)
{
/* printk("Midi6850: Midi busy\n");*/
return -EBUSY;
}
uart6850_cmd(UART_RESET);
uart6850_input_loop();
midi_input_intr = input;
uart6850_opened = mode;
poll_uart6850(0); /*
* Enable input polling
*/
return 0;
}
static void uart6850_close(int dev)
{
uart6850_cmd(UART_MODE_ON);
del_timer(&uart6850_timer);
uart6850_opened = 0;
}
static int uart6850_out(int dev, unsigned char midi_byte)
{
int timeout;
unsigned long flags;
/*
* Test for input since pending input seems to block the output.
*/
spin_lock_irqsave(&lock,flags);
if (input_avail())
uart6850_input_loop();
spin_unlock_irqrestore(&lock,flags);
/*
* Sometimes it takes about 13000 loops before the output becomes ready
* (After reset). Normally it takes just about 10 loops.
*/
for (timeout = 30000; timeout > 0 && !output_ready(); timeout--); /*
* Wait
*/
if (!output_ready())
{
printk(KERN_WARNING "Midi6850: Timeout\n");
return 0;
}
uart6850_write(midi_byte);
return 1;
}
static inline int uart6850_command(int dev, unsigned char *midi_byte)
{
return 1;
}
static inline int uart6850_start_read(int dev)
{
return 0;
}
static inline int uart6850_end_read(int dev)
{
return 0;
}
static inline void uart6850_kick(int dev)
{
}
static inline int uart6850_buffer_status(int dev)
{
return 0; /*
* No data in buffers
*/
}
#define MIDI_SYNTH_NAME "6850 UART Midi"
#define MIDI_SYNTH_CAPS SYNTH_CAP_INPUT
#include "midi_synth.h"
static struct midi_operations uart6850_operations =
{
.owner = THIS_MODULE,
.info = {"6850 UART", 0, 0, SNDCARD_UART6850},
.converter = &std_midi_synth,
.in_info = {0},
.open = uart6850_open,
.close = uart6850_close,
.outputc = uart6850_out,
.start_read = uart6850_start_read,
.end_read = uart6850_end_read,
.kick = uart6850_kick,
.command = uart6850_command,
.buffer_status = uart6850_buffer_status
};
static void __init attach_uart6850(struct address_info *hw_config)
{
int ok, timeout;
unsigned long flags;
if (!uart6850_detected)
return;
if ((my_dev = sound_alloc_mididev()) == -1)
{
printk(KERN_INFO "uart6850: Too many midi devices detected\n");
return;
}
uart6850_base = hw_config->io_base;
uart6850_osp = hw_config->osp;
uart6850_irq = hw_config->irq;
spin_lock_irqsave(&lock,flags);
for (timeout = 30000; timeout > 0 && !output_ready(); timeout--); /*
* Wait
*/
uart6850_cmd(UART_MODE_ON);
ok = 1;
spin_unlock_irqrestore(&lock,flags);
conf_printf("6850 Midi Interface", hw_config);
std_midi_synth.midi_dev = my_dev;
hw_config->slots[4] = my_dev;
midi_devs[my_dev] = &uart6850_operations;
sequencer_init();
}
static inline int reset_uart6850(void)
{
uart6850_read();
return 1; /*
* OK
*/
}
static int __init probe_uart6850(struct address_info *hw_config)
{
int ok;
uart6850_osp = hw_config->osp;
uart6850_base = hw_config->io_base;
uart6850_irq = hw_config->irq;
if (request_irq(uart6850_irq, m6850intr, 0, "MIDI6850", NULL) < 0)
return 0;
ok = reset_uart6850();
uart6850_detected = ok;
return ok;
}
static void __exit unload_uart6850(struct address_info *hw_config)
{
free_irq(hw_config->irq, NULL);
sound_unload_mididev(hw_config->slots[4]);
}
static struct address_info cfg_mpu;
static int __initdata io = -1;
static int __initdata irq = -1;
module_param_hw(io, int, ioport, 0);
module_param_hw(irq, int, irq, 0);
static int __init init_uart6850(void)
{
cfg_mpu.io_base = io;
cfg_mpu.irq = irq;
if (cfg_mpu.io_base == -1 || cfg_mpu.irq == -1) {
printk(KERN_INFO "uart6850: irq and io must be set.\n");
return -EINVAL;
}
if (probe_uart6850(&cfg_mpu))
return -ENODEV;
attach_uart6850(&cfg_mpu);
return 0;
}
static void __exit cleanup_uart6850(void)
{
unload_uart6850(&cfg_mpu);
}
module_init(init_uart6850);
module_exit(cleanup_uart6850);
#ifndef MODULE
static int __init setup_uart6850(char *str)
{
/* io, irq */
int ints[3];
str = get_options(str, ARRAY_SIZE(ints), ints);
io = ints[1];
irq = ints[2];
return 1;
}
__setup("uart6850=", setup_uart6850);
#endif
MODULE_LICENSE("GPL");