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[linux-2.6.git] / drivers / i2c / busses / i2c-ibm_iic.c

diff --git a/drivers/i2c/busses/i2c-ibm_iic.c b/drivers/i2c/busses/i2c-ibm_iic.c
index a25218d..962184b 100644 (file)
--- a/drivers/i2c/busses/i2c-ibm_iic.c
+++ b/drivers/i2c/busses/i2c-ibm_iic.c
@@ -45,7 +45,7 @@
 
 #include "i2c-ibm_iic.h"
 
-#define DRIVER_VERSION "2.1"
+#define DRIVER_VERSION "2.01"
 
 MODULE_DESCRIPTION("IBM IIC driver v" DRIVER_VERSION);
 MODULE_LICENSE("GPL");
@@ -96,31 +96,6 @@ static void dump_iic_regs(const char* header, struct ibm_iic_private* dev)
 #  define DUMP_REGS(h,dev)     ((void)0)
 #endif
 
-/* Bus timings (in ns) for bit-banging */
-static struct i2c_timings {
-       unsigned int hd_sta;
-       unsigned int su_sto;
-       unsigned int low;
-       unsigned int high;
-       unsigned int buf;
-} timings [] = {
-/* Standard mode (100 KHz) */
-{
-       .hd_sta = 4000,
-       .su_sto = 4000,
-       .low    = 4700,
-       .high   = 4000,
-       .buf    = 4700,
-},
-/* Fast mode (400 KHz) */
-{
-       .hd_sta = 600,
-       .su_sto = 600,
-       .low    = 1300,
-       .high   = 600,
-       .buf    = 1300,
-}};
-
 /* Enable/disable interrupt generation */
 static inline void iic_interrupt_mode(struct ibm_iic_private* dev, int enable)
 {
@@ -220,104 +195,6 @@ static void iic_dev_reset(struct ibm_iic_private* dev)
        iic_dev_init(dev);
 }
 
-/*
- * Do 0-length transaction using bit-banging through IIC_DIRECTCNTL register.
- */
-
-/* Wait for SCL and/or SDA to be high */
-static int iic_dc_wait(volatile struct iic_regs *iic, u8 mask)
-{
-       unsigned long x = jiffies + HZ / 28 + 2;
-       while ((in_8(&iic->directcntl) & mask) != mask){
-               if (unlikely(time_after(jiffies, x)))
-                       return -1;
-               cond_resched();
-       }
-       return 0;
-}
-
-static int iic_smbus_quick(struct ibm_iic_private* dev, const struct i2c_msg* p)
-{
-       volatile struct iic_regs* iic = dev->vaddr;
-       const struct i2c_timings* t = &timings[dev->fast_mode ? 1 : 0];
-       u8 mask, v, sda;
-       int i, res;
-
-       /* Only 7-bit addresses are supported */
-       if (unlikely(p->flags & I2C_M_TEN)){
-               DBG("%d: smbus_quick - 10 bit addresses are not supported\n",
-                       dev->idx);
-               return -EINVAL;
-       }
-
-       DBG("%d: smbus_quick(0x%02x)\n", dev->idx, p->addr);
-
-       /* Reset IIC interface */
-       out_8(&iic->xtcntlss, XTCNTLSS_SRST);
-
-       /* Wait for bus to become free */
-       out_8(&iic->directcntl, DIRCNTL_SDAC | DIRCNTL_SCC);
-       if (unlikely(iic_dc_wait(iic, DIRCNTL_MSDA | DIRCNTL_MSC)))
-               goto err;
-       ndelay(t->buf);
-
-       /* START */
-       out_8(&iic->directcntl, DIRCNTL_SCC);
-       sda = 0;
-       ndelay(t->hd_sta);
-
-       /* Send address */
-       v = (u8)((p->addr << 1) | ((p->flags & I2C_M_RD) ? 1 : 0));
-       for (i = 0, mask = 0x80; i < 8; ++i, mask >>= 1){
-               out_8(&iic->directcntl, sda);
-               ndelay(t->low / 2);
-               sda = (v & mask) ? DIRCNTL_SDAC : 0;
-               out_8(&iic->directcntl, sda);
-               ndelay(t->low / 2);
-
-               out_8(&iic->directcntl, DIRCNTL_SCC | sda);
-               if (unlikely(iic_dc_wait(iic, DIRCNTL_MSC)))
-                       goto err;
-               ndelay(t->high);
-       }
-
-       /* ACK */
-       out_8(&iic->directcntl, sda);
-       ndelay(t->low / 2);
-       out_8(&iic->directcntl, DIRCNTL_SDAC);
-       ndelay(t->low / 2);
-       out_8(&iic->directcntl, DIRCNTL_SDAC | DIRCNTL_SCC);
-       if (unlikely(iic_dc_wait(iic, DIRCNTL_MSC)))
-               goto err;
-       res = (in_8(&iic->directcntl) & DIRCNTL_MSDA) ? -EREMOTEIO : 1;
-       ndelay(t->high);
-
-       /* STOP */
-       out_8(&iic->directcntl, 0);
-       ndelay(t->low);
-       out_8(&iic->directcntl, DIRCNTL_SCC);
-       if (unlikely(iic_dc_wait(iic, DIRCNTL_MSC)))
-               goto err;
-       ndelay(t->su_sto);
-       out_8(&iic->directcntl, DIRCNTL_SDAC | DIRCNTL_SCC);
-
-       ndelay(t->buf);
-
-       DBG("%d: smbus_quick -> %s\n", dev->idx, res ? "NACK" : "ACK");
-out:
-       /* Remove reset */
-       out_8(&iic->xtcntlss, 0);
-
-       /* Reinitialize interface */
-       iic_dev_init(dev);
-
-       return res;
-err:
-       DBG("%d: smbus_quick - bus is stuck\n", dev->idx);
-       res = -EREMOTEIO;
-       goto out;
-}
-
 /*
  * IIC interrupt handler
  */
@@ -580,10 +457,13 @@ static int iic_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
                if (unlikely(msgs[i].len <= 0)){
                        if (num == 1 && !msgs[0].len){
                                /* Special case for I2C_SMBUS_QUICK emulation.
+                                * Although this logic is FAR FROM PERFECT, this 
+                                * is what previous driver version did.
                                 * IBM IIC doesn't support 0-length transactions
-                                * so we have to emulate them using bit-banging.
+                                * (except bit-banging through IICx_DIRECTCNTL).
                                 */
-                               return iic_smbus_quick(dev, &msgs[0]);
+                               DBG("%d: zero-length msg kludge\n", dev->idx); 
+                               return 0;
                        }
                        DBG("%d: invalid len %d in msg[%d]\n", dev->idx, 
                                msgs[i].len, i);