linux/sound/pci/oxygen/oxygen_io.c
Clemens Ladisch 1e821dd276 [ALSA] oxygen: use AC97 interrupt
After an AC97 register read or write, use the AC97 interrupt instead of
polling to wait for the access to be completed.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
2008-01-31 17:30:17 +01:00

202 lines
5.5 KiB
C

/*
* C-Media CMI8788 driver - helper functions
*
* Copyright (c) Clemens Ladisch <clemens@ladisch.de>
*
*
* This driver is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2.
*
* This driver 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 driver; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/delay.h>
#include <linux/sched.h>
#include <sound/core.h>
#include <asm/io.h>
#include "oxygen.h"
u8 oxygen_read8(struct oxygen *chip, unsigned int reg)
{
return inb(chip->addr + reg);
}
EXPORT_SYMBOL(oxygen_read8);
u16 oxygen_read16(struct oxygen *chip, unsigned int reg)
{
return inw(chip->addr + reg);
}
EXPORT_SYMBOL(oxygen_read16);
u32 oxygen_read32(struct oxygen *chip, unsigned int reg)
{
return inl(chip->addr + reg);
}
EXPORT_SYMBOL(oxygen_read32);
void oxygen_write8(struct oxygen *chip, unsigned int reg, u8 value)
{
outb(value, chip->addr + reg);
}
EXPORT_SYMBOL(oxygen_write8);
void oxygen_write16(struct oxygen *chip, unsigned int reg, u16 value)
{
outw(value, chip->addr + reg);
}
EXPORT_SYMBOL(oxygen_write16);
void oxygen_write32(struct oxygen *chip, unsigned int reg, u32 value)
{
outl(value, chip->addr + reg);
}
EXPORT_SYMBOL(oxygen_write32);
void oxygen_write8_masked(struct oxygen *chip, unsigned int reg,
u8 value, u8 mask)
{
u8 tmp = inb(chip->addr + reg);
outb((tmp & ~mask) | (value & mask), chip->addr + reg);
}
EXPORT_SYMBOL(oxygen_write8_masked);
void oxygen_write16_masked(struct oxygen *chip, unsigned int reg,
u16 value, u16 mask)
{
u16 tmp = inw(chip->addr + reg);
outw((tmp & ~mask) | (value & mask), chip->addr + reg);
}
EXPORT_SYMBOL(oxygen_write16_masked);
void oxygen_write32_masked(struct oxygen *chip, unsigned int reg,
u32 value, u32 mask)
{
u32 tmp = inl(chip->addr + reg);
outl((tmp & ~mask) | (value & mask), chip->addr + reg);
}
EXPORT_SYMBOL(oxygen_write32_masked);
static int oxygen_ac97_wait(struct oxygen *chip, unsigned int mask)
{
u8 status = 0;
/*
* Reading the status register also clears the bits, so we have to save
* the read bits in status.
*/
wait_event_timeout(chip->ac97_waitqueue,
({ status |= oxygen_read8(chip, OXYGEN_AC97_INTERRUPT_STATUS);
status & mask; }),
msecs_to_jiffies(1) + 1);
/*
* Check even after a timeout because this function should not require
* the AC'97 interrupt to be enabled.
*/
status |= oxygen_read8(chip, OXYGEN_AC97_INTERRUPT_STATUS);
return status & mask ? 0 : -EIO;
}
/*
* About 10% of AC'97 register reads or writes fail to complete, but even those
* where the controller indicates completion aren't guaranteed to have actually
* happened.
*
* It's hard to assign blame to either the controller or the codec because both
* were made by C-Media ...
*/
void oxygen_write_ac97(struct oxygen *chip, unsigned int codec,
unsigned int index, u16 data)
{
unsigned int count, succeeded;
u32 reg;
reg = data;
reg |= index << OXYGEN_AC97_REG_ADDR_SHIFT;
reg |= OXYGEN_AC97_REG_DIR_WRITE;
reg |= codec << OXYGEN_AC97_REG_CODEC_SHIFT;
succeeded = 0;
for (count = 5; count > 0; --count) {
udelay(5);
oxygen_write32(chip, OXYGEN_AC97_REGS, reg);
/* require two "completed" writes, just to be sure */
if (oxygen_ac97_wait(chip, OXYGEN_AC97_INT_WRITE_DONE) >= 0 &&
++succeeded >= 2)
return;
}
snd_printk(KERN_ERR "AC'97 write timeout\n");
}
EXPORT_SYMBOL(oxygen_write_ac97);
u16 oxygen_read_ac97(struct oxygen *chip, unsigned int codec,
unsigned int index)
{
unsigned int count;
unsigned int last_read = UINT_MAX;
u32 reg;
reg = index << OXYGEN_AC97_REG_ADDR_SHIFT;
reg |= OXYGEN_AC97_REG_DIR_READ;
reg |= codec << OXYGEN_AC97_REG_CODEC_SHIFT;
for (count = 5; count > 0; --count) {
udelay(5);
oxygen_write32(chip, OXYGEN_AC97_REGS, reg);
udelay(10);
if (oxygen_ac97_wait(chip, OXYGEN_AC97_INT_READ_DONE) >= 0) {
u16 value = oxygen_read16(chip, OXYGEN_AC97_REGS);
/* we require two consecutive reads of the same value */
if (value == last_read)
return value;
last_read = value;
/*
* Invert the register value bits to make sure that two
* consecutive unsuccessful reads do not return the same
* value.
*/
reg ^= 0xffff;
}
}
snd_printk(KERN_ERR "AC'97 read timeout on codec %u\n", codec);
return 0;
}
EXPORT_SYMBOL(oxygen_read_ac97);
void oxygen_write_ac97_masked(struct oxygen *chip, unsigned int codec,
unsigned int index, u16 data, u16 mask)
{
u16 value = oxygen_read_ac97(chip, codec, index);
value &= ~mask;
value |= data & mask;
oxygen_write_ac97(chip, codec, index, value);
}
EXPORT_SYMBOL(oxygen_write_ac97_masked);
void oxygen_write_spi(struct oxygen *chip, u8 control, unsigned int data)
{
unsigned int count;
/* should not need more than 7.68 us (24 * 320 ns) */
count = 10;
while ((oxygen_read8(chip, OXYGEN_SPI_CONTROL) & OXYGEN_SPI_BUSY)
&& count > 0) {
udelay(1);
--count;
}
spin_lock_irq(&chip->reg_lock);
oxygen_write8(chip, OXYGEN_SPI_DATA1, data);
oxygen_write8(chip, OXYGEN_SPI_DATA2, data >> 8);
if (control & OXYGEN_SPI_DATA_LENGTH_3)
oxygen_write8(chip, OXYGEN_SPI_DATA3, data >> 16);
oxygen_write8(chip, OXYGEN_SPI_CONTROL, control);
spin_unlock_irq(&chip->reg_lock);
}
EXPORT_SYMBOL(oxygen_write_spi);