linux/sound/isa/ad1848/ad1848.c
David Howells e992ef5705 Annotate hardware config module parameters in sound/isa/
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/isa/.

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: alsa-devel@alsa-project.org
2017-04-20 12:02:32 +01:00

174 lines
5.0 KiB
C

/*
* Generic driver for AD1848/AD1847/CS4248 chips (0.1 Alpha)
* Copyright (c) by Tugrul Galatali <galatalt@stuy.edu>,
* Jaroslav Kysela <perex@perex.cz>
* Based on card-4232.c by Jaroslav Kysela <perex@perex.cz>
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <linux/init.h>
#include <linux/err.h>
#include <linux/isa.h>
#include <linux/time.h>
#include <linux/wait.h>
#include <linux/module.h>
#include <sound/core.h>
#include <sound/wss.h>
#include <sound/initval.h>
#define CRD_NAME "Generic AD1848/AD1847/CS4248"
#define DEV_NAME "ad1848"
MODULE_DESCRIPTION(CRD_NAME);
MODULE_AUTHOR("Tugrul Galatali <galatalt@stuy.edu>, Jaroslav Kysela <perex@perex.cz>");
MODULE_LICENSE("GPL");
MODULE_SUPPORTED_DEVICE("{{Analog Devices,AD1848},"
"{Analog Devices,AD1847},"
"{Crystal Semiconductors,CS4248}}");
static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */
static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* ID for this card */
static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE; /* Enable this card */
static long port[SNDRV_CARDS] = SNDRV_DEFAULT_PORT; /* PnP setup */
static int irq[SNDRV_CARDS] = SNDRV_DEFAULT_IRQ; /* 5,7,9,11,12,15 */
static int dma1[SNDRV_CARDS] = SNDRV_DEFAULT_DMA; /* 0,1,3,5,6,7 */
static bool thinkpad[SNDRV_CARDS]; /* Thinkpad special case */
module_param_array(index, int, NULL, 0444);
MODULE_PARM_DESC(index, "Index value for " CRD_NAME " soundcard.");
module_param_array(id, charp, NULL, 0444);
MODULE_PARM_DESC(id, "ID string for " CRD_NAME " soundcard.");
module_param_array(enable, bool, NULL, 0444);
MODULE_PARM_DESC(enable, "Enable " CRD_NAME " soundcard.");
module_param_hw_array(port, long, ioport, NULL, 0444);
MODULE_PARM_DESC(port, "Port # for " CRD_NAME " driver.");
module_param_hw_array(irq, int, irq, NULL, 0444);
MODULE_PARM_DESC(irq, "IRQ # for " CRD_NAME " driver.");
module_param_hw_array(dma1, int, dma, NULL, 0444);
MODULE_PARM_DESC(dma1, "DMA1 # for " CRD_NAME " driver.");
module_param_array(thinkpad, bool, NULL, 0444);
MODULE_PARM_DESC(thinkpad, "Enable only for the onboard CS4248 of IBM Thinkpad 360/750/755 series.");
static int snd_ad1848_match(struct device *dev, unsigned int n)
{
if (!enable[n])
return 0;
if (port[n] == SNDRV_AUTO_PORT) {
dev_err(dev, "please specify port\n");
return 0;
}
if (irq[n] == SNDRV_AUTO_IRQ) {
dev_err(dev, "please specify irq\n");
return 0;
}
if (dma1[n] == SNDRV_AUTO_DMA) {
dev_err(dev, "please specify dma1\n");
return 0;
}
return 1;
}
static int snd_ad1848_probe(struct device *dev, unsigned int n)
{
struct snd_card *card;
struct snd_wss *chip;
int error;
error = snd_card_new(dev, index[n], id[n], THIS_MODULE, 0, &card);
if (error < 0)
return error;
error = snd_wss_create(card, port[n], -1, irq[n], dma1[n], -1,
thinkpad[n] ? WSS_HW_THINKPAD : WSS_HW_DETECT,
0, &chip);
if (error < 0)
goto out;
card->private_data = chip;
error = snd_wss_pcm(chip, 0);
if (error < 0)
goto out;
error = snd_wss_mixer(chip);
if (error < 0)
goto out;
strcpy(card->driver, "AD1848");
strcpy(card->shortname, chip->pcm->name);
sprintf(card->longname, "%s at 0x%lx, irq %d, dma %d",
chip->pcm->name, chip->port, irq[n], dma1[n]);
if (thinkpad[n])
strcat(card->longname, " [Thinkpad]");
error = snd_card_register(card);
if (error < 0)
goto out;
dev_set_drvdata(dev, card);
return 0;
out: snd_card_free(card);
return error;
}
static int snd_ad1848_remove(struct device *dev, unsigned int n)
{
snd_card_free(dev_get_drvdata(dev));
return 0;
}
#ifdef CONFIG_PM
static int snd_ad1848_suspend(struct device *dev, unsigned int n, pm_message_t state)
{
struct snd_card *card = dev_get_drvdata(dev);
struct snd_wss *chip = card->private_data;
snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
chip->suspend(chip);
return 0;
}
static int snd_ad1848_resume(struct device *dev, unsigned int n)
{
struct snd_card *card = dev_get_drvdata(dev);
struct snd_wss *chip = card->private_data;
chip->resume(chip);
snd_power_change_state(card, SNDRV_CTL_POWER_D0);
return 0;
}
#endif
static struct isa_driver snd_ad1848_driver = {
.match = snd_ad1848_match,
.probe = snd_ad1848_probe,
.remove = snd_ad1848_remove,
#ifdef CONFIG_PM
.suspend = snd_ad1848_suspend,
.resume = snd_ad1848_resume,
#endif
.driver = {
.name = DEV_NAME
}
};
module_isa_driver(snd_ad1848_driver, SNDRV_CARDS);