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   1 /*
   2  * C-Media CMI8788 driver - helper functions
   3  *
   4  * Copyright (c) Clemens Ladisch <clemens@ladisch.de>
   5  *
   6  *
   7  *  This driver is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License, version 2.
   9  *
  10  *  This driver is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this driver; if not, write to the Free Software
  17  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  18  */
  19
  20 #include <linux/delay.h>
  21 #include <linux/sched.h>
  22 #include <sound/core.h>
  23 #include <asm/io.h>
  24 #include "oxygen.h"
  25
  26 u8 oxygen_read8(struct oxygen *chip, unsigned int reg)
  27 {
  28         return inb(chip->addr + reg);
  29 }
  30 EXPORT_SYMBOL(oxygen_read8);
  31
  32 u16 oxygen_read16(struct oxygen *chip, unsigned int reg)
  33 {
  34         return inw(chip->addr + reg);
  35 }
  36 EXPORT_SYMBOL(oxygen_read16);
  37
  38 u32 oxygen_read32(struct oxygen *chip, unsigned int reg)
  39 {
  40         return inl(chip->addr + reg);
  41 }
  42 EXPORT_SYMBOL(oxygen_read32);
  43
  44 void oxygen_write8(struct oxygen *chip, unsigned int reg, u8 value)
  45 {
  46         outb(value, chip->addr + reg);
  47 }
  48 EXPORT_SYMBOL(oxygen_write8);
  49
  50 void oxygen_write16(struct oxygen *chip, unsigned int reg, u16 value)
  51 {
  52         outw(value, chip->addr + reg);
  53 }
  54 EXPORT_SYMBOL(oxygen_write16);
  55
  56 void oxygen_write32(struct oxygen *chip, unsigned int reg, u32 value)
  57 {
  58         outl(value, chip->addr + reg);
  59 }
  60 EXPORT_SYMBOL(oxygen_write32);
  61
  62 void oxygen_write8_masked(struct oxygen *chip, unsigned int reg,
  63                           u8 value, u8 mask)
  64 {
  65         u8 tmp = inb(chip->addr + reg);
  66         outb((tmp & ~mask) | (value & mask), chip->addr + reg);
  67 }
  68 EXPORT_SYMBOL(oxygen_write8_masked);
  69
  70 void oxygen_write16_masked(struct oxygen *chip, unsigned int reg,
  71                            u16 value, u16 mask)
  72 {
  73         u16 tmp = inw(chip->addr + reg);
  74         outw((tmp & ~mask) | (value & mask), chip->addr + reg);
  75 }
  76 EXPORT_SYMBOL(oxygen_write16_masked);
  77
  78 void oxygen_write32_masked(struct oxygen *chip, unsigned int reg,
  79                            u32 value, u32 mask)
  80 {
  81         u32 tmp = inl(chip->addr + reg);
  82         outl((tmp & ~mask) | (value & mask), chip->addr + reg);
  83 }
  84 EXPORT_SYMBOL(oxygen_write32_masked);
  85
  86 static int oxygen_ac97_wait(struct oxygen *chip, unsigned int mask)
  87 {
  88         unsigned long timeout = jiffies + msecs_to_jiffies(1);
  89         do {
  90                 udelay(5);
  91                 cond_resched();
  92                 if (oxygen_read8(chip, OXYGEN_AC97_INTERRUPT_STATUS) & mask)
  93                         return 0;
  94         } while (time_after_eq(timeout, jiffies));
  95         return -EIO;
  96 }
  97
  98 /*
  99  * About 10% of AC'97 register reads or writes fail to complete, but even those
 100  * where the controller indicates completion aren't guaranteed to have actually
 101  * happened.
 102  *
 103  * It's hard to assign blame to either the controller or the codec because both
 104  * were made by C-Media ...
 105  */
 106
 107 void oxygen_write_ac97(struct oxygen *chip, unsigned int codec,
 108                        unsigned int index, u16 data)
 109 {
 110         unsigned int count, succeeded;
 111         u32 reg;
 112
 113         reg = data;
 114         reg |= index << OXYGEN_AC97_REG_ADDR_SHIFT;
 115         reg |= OXYGEN_AC97_REG_DIR_WRITE;
 116         reg |= codec << OXYGEN_AC97_REG_CODEC_SHIFT;
 117         succeeded = 0;
 118         for (count = 5; count > 0; --count) {
 119                 udelay(5);
 120                 oxygen_write32(chip, OXYGEN_AC97_REGS, reg);
 121                 /* require two "completed" writes, just to be sure */
 122                 if (oxygen_ac97_wait(chip, OXYGEN_AC97_INT_WRITE_DONE) >= 0 &&
 123                     ++succeeded >= 2)
 124                         return;
 125         }
 126         snd_printk(KERN_ERR "AC'97 write timeout\n");
 127 }
 128 EXPORT_SYMBOL(oxygen_write_ac97);
 129
 130 u16 oxygen_read_ac97(struct oxygen *chip, unsigned int codec,
 131                      unsigned int index)
 132 {
 133         unsigned int count;
 134         unsigned int last_read = UINT_MAX;
 135         u32 reg;
 136
 137         reg = index << OXYGEN_AC97_REG_ADDR_SHIFT;
 138         reg |= OXYGEN_AC97_REG_DIR_READ;
 139         reg |= codec << OXYGEN_AC97_REG_CODEC_SHIFT;
 140         for (count = 5; count > 0; --count) {
 141                 udelay(5);
 142                 oxygen_write32(chip, OXYGEN_AC97_REGS, reg);
 143                 udelay(10);
 144                 if (oxygen_ac97_wait(chip, OXYGEN_AC97_INT_READ_DONE) >= 0) {
 145                         u16 value = oxygen_read16(chip, OXYGEN_AC97_REGS);
 146                         /* we require two consecutive reads of the same value */
 147                         if (value == last_read)
 148                                 return value;
 149                         last_read = value;
 150                         /*
 151                          * Invert the register value bits to make sure that two
 152                          * consecutive unsuccessful reads do not return the same
 153                          * value.
 154                          */
 155                         reg ^= 0xffff;
 156                 }
 157         }
 158         snd_printk(KERN_ERR "AC'97 read timeout on codec %u\n", codec);
 159         return 0;
 160 }
 161 EXPORT_SYMBOL(oxygen_read_ac97);
 162
 163 void oxygen_write_ac97_masked(struct oxygen *chip, unsigned int codec,
 164                               unsigned int index, u16 data, u16 mask)
 165 {
 166         u16 value = oxygen_read_ac97(chip, codec, index);
 167         value &= ~mask;
 168         value |= data & mask;
 169         oxygen_write_ac97(chip, codec, index, value);
 170 }
 171 EXPORT_SYMBOL(oxygen_write_ac97_masked);
 172
 173 void oxygen_write_spi(struct oxygen *chip, u8 control, unsigned int data)
 174 {
 175         unsigned int count;
 176
 177         /* should not need more than 7.68 us (24 * 320 ns) */
 178         count = 10;
 179         while ((oxygen_read8(chip, OXYGEN_SPI_CONTROL) & OXYGEN_SPI_BUSY)
 180                && count > 0) {
 181                 udelay(1);
 182                 --count;
 183         }
 184
 185         spin_lock_irq(&chip->reg_lock);
 186         oxygen_write8(chip, OXYGEN_SPI_DATA1, data);
 187         oxygen_write8(chip, OXYGEN_SPI_DATA2, data >> 8);
 188         if (control & OXYGEN_SPI_DATA_LENGTH_3)
 189                 oxygen_write8(chip, OXYGEN_SPI_DATA3, data >> 16);
 190         oxygen_write8(chip, OXYGEN_SPI_CONTROL, control);
 191         spin_unlock_irq(&chip->reg_lock);
 192 }
 193 EXPORT_SYMBOL(oxygen_write_spi);