git.oblomov.eu Git - nouveau/blob - src/nv_i2c.c

   1
   2 #include "nv_include.h"
   3
   4 /*
   5  * DDC1 support only requires DDC_SDA_MASK,
   6  * DDC2 support requires DDC_SDA_MASK and DDC_SCL_MASK
   7  */
   8 #define DDC_SDA_READ_MASK  (1 << 3)
   9 #define DDC_SCL_READ_MASK  (1 << 2)
  10 #define DDC_SDA_WRITE_MASK (1 << 4)
  11 #define DDC_SCL_WRITE_MASK (1 << 5)
  12
  13 static void
  14 NVI2CGetBits(I2CBusPtr b, int *clock, int *data)
  15 {
  16         NVPtr pNv = NVPTR(xf86Screens[b->scrnIndex]);
  17         unsigned char val;
  18
  19         /* Get the result. */
  20         /* Doing this on head 0 seems fine. */
  21         val = NVReadVgaCrtc(pNv, 0, b->DriverPrivate.uval);
  22
  23         *clock = (val & DDC_SCL_READ_MASK) != 0;
  24         *data  = (val & DDC_SDA_READ_MASK) != 0;
  25 }
  26
  27 static void
  28 NVI2CPutBits(I2CBusPtr b, int clock, int data)
  29 {
  30         NVPtr pNv = NVPTR(xf86Screens[b->scrnIndex]);
  31         unsigned char val;
  32
  33         /* Doing this on head 0 seems fine. */
  34         val = NVReadVgaCrtc(pNv, 0, b->DriverPrivate.uval + 1) & 0xf0;
  35         if (clock)
  36                 val |= DDC_SCL_WRITE_MASK;
  37         else
  38                 val &= ~DDC_SCL_WRITE_MASK;
  39
  40         if (data)
  41                 val |= DDC_SDA_WRITE_MASK;
  42         else
  43                 val &= ~DDC_SDA_WRITE_MASK;
  44
  45         /* Doing this on head 0 seems fine. */
  46         NVWriteVgaCrtc(pNv, 0, b->DriverPrivate.uval + 1, val | 0x1);
  47 }
  48
  49 Bool
  50 NV_I2CInit(ScrnInfoPtr pScrn, I2CBusPtr *bus_ptr, int i2c_reg, char *name)
  51 {
  52         I2CBusPtr pI2CBus;
  53
  54         pI2CBus = xf86CreateI2CBusRec();
  55         if(!pI2CBus)
  56                 return FALSE;
  57
  58         pI2CBus->BusName    = name;
  59         pI2CBus->scrnIndex  = pScrn->scrnIndex;
  60         pI2CBus->I2CPutBits = NVI2CPutBits;
  61         pI2CBus->I2CGetBits = NVI2CGetBits;
  62         pI2CBus->AcknTimeout = 5;
  63
  64         pI2CBus->DriverPrivate.uval = i2c_reg;
  65
  66         if (!xf86I2CBusInit(pI2CBus)) {
  67                 return FALSE;
  68         }
  69
  70         *bus_ptr = pI2CBus;
  71         return TRUE;
  72 }
  73