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Commit 95a5b085 authored by Takashi Iwai's avatar Takashi Iwai Committed by Jaroslav Kysela
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[ALSA] Fixes to follow the standard coding style 

Fixed the tutorial to follow the standard kernel coding style.
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
Signed-off-by: default avatarJaroslav Kysela <perex@suse.cz>
parent 5b31954e
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Showing with 77 additions and 48 deletions
Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl
View file @ 95a5b085
......@@ -18,8 +18,8 @@
</affiliation>
</author>
<date>November 17, 2005</date>
<edition>0.3.6</edition>
<date>July 26, 2007</date>
<edition>0.3.6.1</edition>
<abstract>
<para>
......@@ -405,8 +405,9 @@
/* definition of the chip-specific record */
struct mychip {
struct snd_card *card;
// rest of implementation will be in the section
// "PCI Resource Managements"
/* rest of implementation will be in the section
* "PCI Resource Managements"
*/
};
/* chip-specific destructor
......@@ -414,7 +415,7 @@
*/
static int snd_mychip_free(struct mychip *chip)
{
.... // will be implemented later...
.... /* will be implemented later... */
}
/* component-destructor
......@@ -440,8 +441,9 @@
*rchip = NULL;
// check PCI availability here
// (see "PCI Resource Managements")
/* check PCI availability here
* (see "PCI Resource Managements")
*/
....
/* allocate a chip-specific data with zero filled */
......@@ -451,12 +453,13 @@
chip->card = card;
// rest of initialization here; will be implemented
// later, see "PCI Resource Managements"
/* rest of initialization here; will be implemented
* later, see "PCI Resource Managements"
*/
....
if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL,
chip, &ops)) < 0) {
err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops);
if (err < 0) {
snd_mychip_free(chip);
return err;
}
......@@ -490,7 +493,8 @@
return -ENOMEM;
/* (3) */
if ((err = snd_mychip_create(card, pci, &chip)) < 0) {
err = snd_mychip_create(card, pci, &chip);
if (err < 0) {
snd_card_free(card);
return err;
}
......@@ -502,10 +506,11 @@
card->shortname, chip->ioport, chip->irq);
/* (5) */
.... // implemented later
.... /* implemented later */
/* (6) */
if ((err = snd_card_register(card)) < 0) {
err = snd_card_register(card);
if (err < 0) {
snd_card_free(card);
return err;
}
......@@ -605,7 +610,8 @@
<![CDATA[
struct mychip *chip;
....
if ((err = snd_mychip_create(card, pci, &chip)) < 0) {
err = snd_mychip_create(card, pci, &chip);
if (err < 0) {
snd_card_free(card);
return err;
}
......@@ -666,7 +672,8 @@
<informalexample>
<programlisting>
<![CDATA[
if ((err = snd_card_register(card)) < 0) {
err = snd_card_register(card);
if (err < 0) {
snd_card_free(card);
return err;
}
......@@ -1091,7 +1098,7 @@
static int snd_mychip_free(struct mychip *chip)
{
/* disable hardware here if any */
.... // (not implemented in this document)
.... /* (not implemented in this document) */
/* release the irq */
if (chip->irq >= 0)
......@@ -1119,7 +1126,8 @@
*rchip = NULL;
/* initialize the PCI entry */
if ((err = pci_enable_device(pci)) < 0)
err = pci_enable_device(pci);
if (err < 0)
return err;
/* check PCI availability (28bit DMA) */
if (pci_set_dma_mask(pci, DMA_28BIT_MASK) < 0 ||
......@@ -1141,7 +1149,8 @@
chip->irq = -1;
/* (1) PCI resource allocation */
if ((err = pci_request_regions(pci, "My Chip")) < 0) {
err = pci_request_regions(pci, "My Chip");
if (err < 0) {
kfree(chip);
pci_disable_device(pci);
return err;
......@@ -1156,10 +1165,10 @@
chip->irq = pci->irq;
/* (2) initialization of the chip hardware */
.... // (not implemented in this document)
.... /* (not implemented in this document) */
if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL,
chip, &ops)) < 0) {
err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops);
if (err < 0) {
snd_mychip_free(chip);
return err;
}
......@@ -1233,7 +1242,8 @@
<informalexample>
<programlisting>
<![CDATA[
if ((err = pci_enable_device(pci)) < 0)
err = pci_enable_device(pci);
if (err < 0)
return err;
if (pci_set_dma_mask(pci, DMA_28BIT_MASK) < 0 ||
pci_set_consistent_dma_mask(pci, DMA_28BIT_MASK) < 0) {
......@@ -1294,7 +1304,8 @@
<informalexample>
<programlisting>
<![CDATA[
if ((err = pci_request_regions(pci, "My Chip")) < 0) {
err = pci_request_regions(pci, "My Chip");
if (err < 0) {
kfree(chip);
pci_disable_device(pci);
return err;
......@@ -1773,7 +1784,8 @@
struct snd_pcm_runtime *runtime = substream->runtime;
runtime->hw = snd_mychip_playback_hw;
// more hardware-initialization will be done here
/* more hardware-initialization will be done here */
....
return 0;
}
......@@ -1781,7 +1793,8 @@
static int snd_mychip_playback_close(struct snd_pcm_substream *substream)
{
struct mychip *chip = snd_pcm_substream_chip(substream);
// the hardware-specific codes will be here
/* the hardware-specific codes will be here */
....
return 0;
}
......@@ -1793,7 +1806,8 @@
struct snd_pcm_runtime *runtime = substream->runtime;
runtime->hw = snd_mychip_capture_hw;
// more hardware-initialization will be done here
/* more hardware-initialization will be done here */
....
return 0;
}
......@@ -1801,7 +1815,8 @@
static int snd_mychip_capture_close(struct snd_pcm_substream *substream)
{
struct mychip *chip = snd_pcm_substream_chip(substream);
// the hardware-specific codes will be here
/* the hardware-specific codes will be here */
....
return 0;
}
......@@ -1844,10 +1859,12 @@
{
switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
// do something to start the PCM engine
/* do something to start the PCM engine */
....
break;
case SNDRV_PCM_TRIGGER_STOP:
// do something to stop the PCM engine
/* do something to stop the PCM engine */
....
break;
default:
return -EINVAL;
......@@ -1900,8 +1917,8 @@
struct snd_pcm *pcm;
int err;
if ((err = snd_pcm_new(chip->card, "My Chip", 0, 1, 1,
&pcm)) < 0)
err = snd_pcm_new(chip->card, "My Chip", 0, 1, 1, &pcm);
if (err < 0)
return err;
pcm->private_data = chip;
strcpy(pcm->name, "My Chip");
......@@ -1939,8 +1956,8 @@
struct snd_pcm *pcm;
int err;
if ((err = snd_pcm_new(chip->card, "My Chip", 0, 1, 1,
&pcm)) < 0)
err = snd_pcm_new(chip->card, "My Chip", 0, 1, 1, &pcm);
if (err < 0)
return err;
pcm->private_data = chip;
strcpy(pcm->name, "My Chip");
......@@ -2097,7 +2114,7 @@
struct mychip *chip = snd_pcm_chip(pcm);
/* free your own data */
kfree(chip->my_private_pcm_data);
// do what you like else
/* do what you like else */
....
}
......@@ -2884,10 +2901,10 @@ struct _snd_pcm_runtime {
<![CDATA[
switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
// do something to start the PCM engine
/* do something to start the PCM engine */
break;
case SNDRV_PCM_TRIGGER_STOP:
// do something to stop the PCM engine
/* do something to stop the PCM engine */
break;
default:
return -EINVAL;
......@@ -3071,7 +3088,7 @@ struct _snd_pcm_runtime {
spin_unlock(&chip->lock);
snd_pcm_period_elapsed(chip->substream);
spin_lock(&chip->lock);
// acknowledge the interrupt if necessary
/* acknowledge the interrupt if necessary */
}
....
spin_unlock(&chip->lock);
......@@ -3134,7 +3151,7 @@ struct _snd_pcm_runtime {
snd_pcm_period_elapsed(substream);
spin_lock(&chip->lock);
}
// acknowledge the interrupt if necessary
/* acknowledge the interrupt if necessary */
}
....
spin_unlock(&chip->lock);
......@@ -3604,7 +3621,7 @@ struct _snd_pcm_runtime {
<title>Example of info callback</title>
<programlisting>
<![CDATA[
static int snd_myctl_info(struct snd_kcontrol *kcontrol,
static int snd_myctl_mono_info(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_info *uinfo)
{
uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
......@@ -3639,7 +3656,7 @@ struct _snd_pcm_runtime {
<informalexample>
<programlisting>
<![CDATA[
static int snd_myctl_info(struct snd_kcontrol *kcontrol,
static int snd_myctl_enum_info(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_info *uinfo)
{
static char *texts[4] = {
......@@ -3658,6 +3675,16 @@ struct _snd_pcm_runtime {
</programlisting>
</informalexample>
</para>
<para>
Some common info callbacks are prepared for easy use:
<function>snd_ctl_boolean_mono_info()</function> and
<function>snd_ctl_boolean_stereo_info()</function>.
Obviously, the former is an info callback for a mono channel
boolean item, just like <function>snd_myctl_mono_info</function>
above, and the latter is for a stereo channel boolean item.
</para>
</section>
<section id="control-interface-callbacks-get">
......@@ -3794,7 +3821,8 @@ struct _snd_pcm_runtime {
<informalexample>
<programlisting>
<![CDATA[
if ((err = snd_ctl_add(card, snd_ctl_new1(&my_control, chip))) < 0)
err = snd_ctl_add(card, snd_ctl_new1(&my_control, chip));
if (err < 0)
return err;
]]>
</programlisting>
......@@ -3880,7 +3908,7 @@ struct _snd_pcm_runtime {
{
struct mychip *chip = ac97->private_data;
....
// read a register value here from the codec
/* read a register value here from the codec */
return the_register_value;
}
......@@ -3889,7 +3917,7 @@ struct _snd_pcm_runtime {
{
struct mychip *chip = ac97->private_data;
....
// write the given register value to the codec
/* write the given register value to the codec */
}
static int snd_mychip_ac97(struct mychip *chip)
......@@ -3902,7 +3930,8 @@ struct _snd_pcm_runtime {
.read = snd_mychip_ac97_read,
};
if ((err = snd_ac97_bus(chip->card, 0, &ops, NULL, &bus)) < 0)
err = snd_ac97_bus(chip->card, 0, &ops, NULL, &bus);
if (err < 0)
return err;
memset(&ac97, 0, sizeof(ac97));
ac97.private_data = chip;
......@@ -4447,10 +4476,10 @@ struct _snd_pcm_runtime {
<informalexample>
<programlisting>
<![CDATA[
struct list_head *list;
struct snd_rawmidi_substream *substream;
list_for_each(list, &rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substreams) {
substream = list_entry(list, struct snd_rawmidi_substream, list);
list_for_each_entry(substream,
&rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substreams,
list {
sprintf(substream->name, "My MIDI Port %d", substream->number + 1);
}
/* same for SNDRV_RAWMIDI_STREAM_INPUT */
......
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