mxc_i2c: add bus recovery support

Add support for calling a function that will toggle the
SCL line to return the bus to idle condition.

The actual toggling function is added in a later patch.

Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>

diff --git a/drivers/i2c/mxc_i2c.c b/drivers/i2c/mxc_i2c.c
index ead6e209b25441d9d2422c68d14a3aa64f03f89a..c00ead1f56bf3538782b1807f71a21efb0c1a685 100644 (file)
--- a/drivers/i2c/mxc_i2c.c
+++ b/drivers/i2c/mxc_i2c.c
@@ -251,6 +251,8 @@ static int i2c_init_transfer_(struct mxc_i2c_regs *i2c_regs,
        return 0;
 }
 
+static int i2c_idle_bus(void *base);
+
 static int i2c_init_transfer(struct mxc_i2c_regs *i2c_regs,
                uchar chip, uint addr, int alen)
 {
@@ -269,6 +271,8 @@ static int i2c_init_transfer(struct mxc_i2c_regs *i2c_regs,
                if (ret != -ERESTART)
                        writeb(0, &i2c_regs->i2cr);     /* Disable controller */
                udelay(100);
+               if (i2c_idle_bus(i2c_regs) < 0)
+                       break;
        }
        printf("%s: give up i2c_regs=%p\n", __func__, i2c_regs);
        return ret;
@@ -390,6 +394,28 @@ void *get_base(void)
 #endif
 }
 
+static struct i2c_parms *i2c_get_parms(void *base)
+{
+       int i = 0;
+       struct i2c_parms *p = srdata.i2c_data;
+       while (i < ARRAY_SIZE(srdata.i2c_data)) {
+               if (p->base == base)
+                       return p;
+               p++;
+               i++;
+       }
+       printf("Invalid I2C base: %p\n", base);
+       return NULL;
+}
+
+static int i2c_idle_bus(void *base)
+{
+       struct i2c_parms *p = i2c_get_parms(base);
+       if (p && p->idle_bus_fn)
+               return p->idle_bus_fn(p->idle_bus_data);
+       return 0;
+}
+
 int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len)
 {
        return bus_i2c_read(get_base(), chip, addr, alen, buf, len);