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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>
This commit is contained in:
Troy Kisky 2012-07-19 08:18:19 +00:00 committed by Heiko Schocher
parent e4ff525f91
commit 96c19bd3ef
1 changed files with 26 additions and 0 deletions
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26
drivers/i2c/mxc_i2c.c
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@ -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);