RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-05-31 10:48:11 +00:00
Code Issues Activity Actions

Kernel: Implement ioctl for the SB16 to change sample rate

Browse source 
Two new ioctl requests are used to get and set the sample rate of the
sound card. The SB16 device keeps track of the sample rate separately,
because I don't want to figure out how to read the sample rate from the
device; it's easier that way.

The soundcard write doesn't set the sample rate to 44100 Hz every time
anymore, as we want to change it externally.
This commit is contained in:
kleines Filmröllchen 2021-08-19 00:04:03 +02:00 • committed by Ali Mohammad Pur
parent 2c9afaf5ac
commit d0ceaa24a6
3 changed files with 34 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

29
Kernel/Devices/SB16.cpp
View file

@ -15,6 +15,7 @@
#include <Kernel/Memory/MemoryManager.h>
#include <Kernel/Sections.h>
#include <Kernel/Thread.h>
#include <LibC/sys/ioctl_numbers.h>
namespace Kernel {
@ -49,6 +50,8 @@ u8 SB16::dsp_read()
/* Changes the sample rate of sound output */
void SB16::set_sample_rate(uint16_t hz)
{
dbgln("SB16: Changing sample rate to {} Hz", hz);
m_sample_rate = hz;
dsp_write(0x41); // output
dsp_write((u8)(hz >> 8));
dsp_write((u8)hz);
@ -115,6 +118,30 @@ UNMAP_AFTER_INIT void SB16::initialize()
dmesgln("SB16: Found version {}.{}", m_major_version, vmin);
set_irq_register(SB16_DEFAULT_IRQ);
dmesgln("SB16: IRQ {}", get_irq_line());
set_sample_rate(m_sample_rate);
}
KResult SB16::ioctl(FileDescription&, unsigned request, Userspace<void*> arg)
{
switch (request) {
case SOUNDCARD_IOCTL_GET_SAMPLE_RATE: {
auto output = static_ptr_cast<u16*>(arg);
if (!copy_to_user(output, &m_sample_rate))
return EFAULT;
return KSuccess;
}
case SOUNDCARD_IOCTL_SET_SAMPLE_RATE: {
auto sample_rate_value = static_cast<u16>(arg.ptr());
if (sample_rate_value == 0)
return EINVAL;
if (m_sample_rate != sample_rate_value)
set_sample_rate(sample_rate_value);
return KSuccess;
}
default:
return EINVAL;
}
}
void SB16::set_irq_register(u8 irq_number)
@ -256,8 +283,6 @@ KResultOr<size_t> SB16::write(FileDescription&, u64, UserOrKernelBuffer const& d
u8 mode = (u8)SampleFormat::Signed | (u8)SampleFormat::Stereo;
const int sample_rate = 44100;
set_sample_rate(sample_rate);
if (!data.read(m_dma_region->vaddr().as_ptr(), length))
return EFAULT;
dma_start(length);