When the code detected that the bus is hung (e.g. SDA stuck low),
send 9 pulses on SCL to try to fixup the bus.
Signed-off-by: Zhao Chenhui <chenhui.z...@freescale.com>
Signed-off-by: Chunhe Lan <chunhe....@freescale.com>
Cc: Scott Wood <scottw...@freescale.com>
Cc: Heiko Schocher <h...@denx.de>
---
Changes for v2:
- No change
Changes for v3:
- Rework codes for the newest mainline
drivers/i2c/fsl_i2c.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 57 insertions(+), 2 deletions(-)
diff --git a/drivers/i2c/fsl_i2c.c b/drivers/i2c/fsl_i2c.c
index 38455e1..44b08f7 100644
--- a/drivers/i2c/fsl_i2c.c
+++ b/drivers/i2c/fsl_i2c.c
@@ -206,9 +206,50 @@ static unsigned int get_i2c_clock(int bus)
return gd->arch.i2c1_clk; /* I2C1 clock */
}
+static int fsl_i2c_fixup(const struct fsl_i2c *dev)
+{
+ const unsigned long long timeout = usec2ticks(CONFIG_I2C_MBB_TIMEOUT);
+ unsigned long long timeval = 0;
+ int ret = -1;
+
+ writeb(I2C_CR_MEN | I2C_CR_MSTA, &dev->cr);
+
+ timeval = get_ticks();
+ while (!(readb(&dev->sr) & I2C_SR_MBB)) {
+ if ((get_ticks() - timeval) > timeout)
+ goto err;
+ }
+
+ if (readb(&dev->sr) & I2C_SR_MAL) {
+ /* SDA is stuck low */
+ writeb(0, &dev->cr);
+ udelay(100);
+ writeb(I2C_CR_MSTA, &dev->cr);
+ writeb(I2C_CR_MEN | I2C_CR_MSTA, &dev->cr);
+ }
+
+ readb(&dev->dr);
+
+ timeval = get_ticks();
+ while (!(readb(&dev->sr) & I2C_SR_MIF)) {
+ if ((get_ticks() - timeval) > timeout)
+ goto err;
+ }
+ ret = 0;
+
+err:
+ writeb(I2C_CR_MEN, &dev->cr);
+ writeb(0, &dev->sr);
+ udelay(100);
+
+ return ret;
+}
+
static void fsl_i2c_init(struct i2c_adapter *adap, int speed, int slaveadd)
{
const struct fsl_i2c *dev;
+ const unsigned long long timeout = usec2ticks(CONFIG_I2C_MBB_TIMEOUT);
+ unsigned long long timeval;
#ifdef CONFIG_SYS_I2C_INIT_BOARD
/* Call board specific i2c bus reset routine before accessing the
@@ -226,6 +267,18 @@ static void fsl_i2c_init(struct i2c_adapter *adap, int
speed, int slaveadd)
writeb(0x0, &dev->sr); /* clear status register */
writeb(I2C_CR_MEN, &dev->cr); /* start I2C controller */
+ timeval = get_ticks();
+ while (readb(&dev->sr) & I2C_SR_MBB) {
+ if ((get_ticks() - timeval) < timeout)
+ continue;
+
+ if (fsl_i2c_fixup(dev))
+ debug("i2c_init: BUS#%d failed to init\n",
+ adap->hwadapnr);
+
+ break;
+ }
+
#ifdef CONFIG_SYS_I2C_BOARD_LATE_INIT
/* Call board specific i2c bus reset routine AFTER the bus has been
* initialized. Use either this callpoint or i2c_init_board;
@@ -394,8 +447,10 @@ fsl_i2c_write(struct i2c_adapter *adap, u8 dev, uint addr,
int alen,
int i = -1; /* signal error */
u8 *a = (u8*)&addr;
- if (i2c_wait4bus(adap) >= 0 &&
- i2c_write_addr(adap, dev, I2C_WRITE_BIT, 0) != 0 &&
+ if (i2c_wait4bus(adap) < 0)
+ return -1;
+
+ if (i2c_write_addr(adap, dev, I2C_WRITE_BIT, 0) != 0 &&
__i2c_write(adap, &a[4 - alen], alen) == alen) {
i = __i2c_write(adap, data, length);
}
--
1.7.6.5
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