diff options
Diffstat (limited to 'Documentation/sound')
| -rw-r--r-- | Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl | 29 |
1 files changed, 25 insertions, 4 deletions
diff --git a/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl b/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl index 23c6c7cde4e..635cbb94357 100644 --- a/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl +++ b/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl @@ -4215,7 +4215,7 @@ struct _snd_pcm_runtime { <programlisting> <![CDATA[ struct snd_rawmidi *rmidi; - snd_mpu401_uart_new(card, 0, MPU401_HW_MPU401, port, integrated, + snd_mpu401_uart_new(card, 0, MPU401_HW_MPU401, port, info_flags, irq, irq_flags, &rmidi); ]]> </programlisting> @@ -4242,15 +4242,36 @@ struct _snd_pcm_runtime { </para> <para> + The 5th argument is bitflags for additional information. When the i/o port address above is a part of the PCI i/o region, the MPU401 i/o port might have been already allocated - (reserved) by the driver itself. In such a case, pass non-zero - to the 5th argument - (<parameter>integrated</parameter>). Otherwise, pass 0 to it, + (reserved) by the driver itself. In such a case, pass a bit flag + <constant>MPU401_INFO_INTEGRATED</constant>, and the mpu401-uart layer will allocate the i/o ports by itself. </para> + <para> + When the controller supports only the input or output MIDI stream, + pass <constant>MPU401_INFO_INPUT</constant> or + <constant>MPU401_INFO_OUTPUT</constant> bitflag, respectively. + Then the rawmidi instance is created as a single stream. + </para> + + <para> + <constant>MPU401_INFO_MMIO</constant> bitflag is used to change + the access method to MMIO (via readb and writeb) instead of + iob and outb. In this case, you have to pass the iomapped address + to <function>snd_mpu401_uart_new()</function>. + </para> + + <para> + When <constant>MPU401_INFO_TX_IRQ</constant> is set, the output + stream isn't checked in the default interrupt handler. The driver + needs to call <function>snd_mpu401_uart_interrupt_tx()</function> + by itself to start processing the output stream in irq handler. + </para> + <para> Usually, the port address corresponds to the command port and port + 1 corresponds to the data port. If not, you may change |