[U-Boot] [PATCH 17/24] mxc_i2c: add bus recovery support

[Troy Kisky]

Toggling the scl line 9 clocks is the standard
way of returning a locked up bus to idle condition.

Signed-off-by: Troy Kisky <troy.kisky at boundarydevices.com>
---
 drivers/i2c/mxc_i2c.c |   26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/i2c/mxc_i2c.c b/drivers/i2c/mxc_i2c.c
index ec05798..339bb6f 100644
--- a/drivers/i2c/mxc_i2c.c
+++ b/drivers/i2c/mxc_i2c.c
@@ -246,6 +246,8 @@ static int i2c_init_transfer_(struct mxc_i2c_regs *i2c_regs,
 	return 0;
 }
 
+static void toggle_i2c(void *i2c_regs);
+
 static int i2c_init_transfer(struct mxc_i2c_regs *i2c_regs,
 		uchar chip, uint addr, int alen)
 {
@@ -264,6 +266,7 @@ static int i2c_init_transfer(struct mxc_i2c_regs *i2c_regs,
 		if (ret != -ERESTART)
 			writeb(0, &i2c_regs->i2cr);	/* Disable controller */
 		udelay(100);
+		toggle_i2c(i2c_regs);
 	}
 	printf("%s: give up i2c_regs=%p\n", __func__, i2c_regs);
 	return ret;
@@ -381,6 +384,29 @@ void *get_base(void)
 #endif
 }
 
+static struct i2c_parms *i2c_get_parms(void *base)
+{
+	int i = 0;
+	struct i2c_parms *p = g_parms;
+	while (i < ARRAY_SIZE(g_parms)) {
+		if (p->base == base)
+			return p;
+		p++;
+		i++;
+	}
+	printf("Invalid I2C base: %p\n", base);
+	return NULL;
+}
+
+static void toggle_i2c(void *base)
+{
+	struct i2c_parms *p = i2c_get_parms(base);
+	if (!p)
+		return;
+	if (p->toggle_fn)
+		p->toggle_fn(p->toggle_data);
+}
+
 int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len)
 {
 	return bus_i2c_read(get_base(), chip, addr, alen, buf, len);
-- 
1.7.9.5