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oxygen_io.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 <sound/mpu401.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);
      chip->saved_registers._8[reg] = value;
}
EXPORT_SYMBOL(oxygen_write8);

void oxygen_write16(struct oxygen *chip, unsigned int reg, u16 value)
{
      outw(value, chip->addr + reg);
      chip->saved_registers._16[reg / 2] = cpu_to_le16(value);
}
EXPORT_SYMBOL(oxygen_write16);

void oxygen_write32(struct oxygen *chip, unsigned int reg, u32 value)
{
      outl(value, chip->addr + reg);
      chip->saved_registers._32[reg / 4] = cpu_to_le32(value);
}
EXPORT_SYMBOL(oxygen_write32);

void oxygen_write8_masked(struct oxygen *chip, unsigned int reg,
                    u8 value, u8 mask)
{
      u8 tmp = inb(chip->addr + reg);
      tmp &= ~mask;
      tmp |= value & mask;
      outb(tmp, chip->addr + reg);
      chip->saved_registers._8[reg] = tmp;
}
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);
      tmp &= ~mask;
      tmp |= value & mask;
      outw(tmp, chip->addr + reg);
      chip->saved_registers._16[reg / 2] = cpu_to_le16(tmp);
}
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);
      tmp &= ~mask;
      tmp |= value & mask;
      outl(tmp, chip->addr + reg);
      chip->saved_registers._32[reg / 4] = cpu_to_le32(tmp);
}
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) {
                  chip->saved_ac97_registers[codec][index / 2] = data;
                  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;
      }

      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);
}
EXPORT_SYMBOL(oxygen_write_spi);

void oxygen_write_i2c(struct oxygen *chip, u8 device, u8 map, u8 data)
{
      unsigned long timeout;

      /* should not need more than about 300 us */
      timeout = jiffies + msecs_to_jiffies(1);
      do {
            if (!(oxygen_read16(chip, OXYGEN_2WIRE_BUS_STATUS)
                  & OXYGEN_2WIRE_BUSY))
                  break;
            udelay(1);
            cond_resched();
      } while (time_after_eq(timeout, jiffies));

      oxygen_write8(chip, OXYGEN_2WIRE_MAP, map);
      oxygen_write8(chip, OXYGEN_2WIRE_DATA, data);
      oxygen_write8(chip, OXYGEN_2WIRE_CONTROL,
                  device | OXYGEN_2WIRE_DIR_WRITE);
}
EXPORT_SYMBOL(oxygen_write_i2c);

static void _write_uart(struct oxygen *chip, unsigned int port, u8 data)
{
      if (oxygen_read8(chip, OXYGEN_MPU401 + 1) & MPU401_TX_FULL)
            msleep(1);
      oxygen_write8(chip, OXYGEN_MPU401 + port, data);
}

void oxygen_reset_uart(struct oxygen *chip)
{
      _write_uart(chip, 1, MPU401_RESET);
      msleep(1); /* wait for ACK */
      _write_uart(chip, 1, MPU401_ENTER_UART);
}
EXPORT_SYMBOL(oxygen_reset_uart);

void oxygen_write_uart(struct oxygen *chip, u8 data)
{
      _write_uart(chip, 0, data);
}
EXPORT_SYMBOL(oxygen_write_uart);

u16 oxygen_read_eeprom(struct oxygen *chip, unsigned int index)
{
      unsigned int timeout;

      oxygen_write8(chip, OXYGEN_EEPROM_CONTROL,
                  index | OXYGEN_EEPROM_DIR_READ);
      for (timeout = 0; timeout < 100; ++timeout) {
            udelay(1);
            if (!(oxygen_read8(chip, OXYGEN_EEPROM_STATUS)
                  & OXYGEN_EEPROM_BUSY))
                  break;
      }
      return oxygen_read16(chip, OXYGEN_EEPROM_DATA);
}

void oxygen_write_eeprom(struct oxygen *chip, unsigned int index, u16 value)
{
      unsigned int timeout;

      oxygen_write16(chip, OXYGEN_EEPROM_DATA, value);
      oxygen_write8(chip, OXYGEN_EEPROM_CONTROL,
                  index | OXYGEN_EEPROM_DIR_WRITE);
      for (timeout = 0; timeout < 10; ++timeout) {
            msleep(1);
            if (!(oxygen_read8(chip, OXYGEN_EEPROM_STATUS)
                  & OXYGEN_EEPROM_BUSY))
                  return;
      }
      snd_printk(KERN_ERR "EEPROM write timeout\n");
}

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