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[BACKPORT] kinetis_i2c ensure timeout on bus error #31

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merged 1 commit into from
Aug 25, 2018
Merged

[BACKPORT] kinetis_i2c ensure timeout on bus error #31

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44 changes: 28 additions & 16 deletions arch/arm/src/kinetis/kinetis_i2c.c
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Original file line number Diff line number Diff line change
Expand Up @@ -74,7 +74,7 @@
* Pre-processor Definitions
****************************************************************************/

#define I2C_TIMEOUT (20*1000/CONFIG_USEC_PER_TICK) /* 20 mS */
#define I2C_TIMEOUT USEC2TICK(20*1000) /* 20 mS */

#define I2C_DEFAULT_FREQUENCY 400000

Expand Down Expand Up @@ -790,6 +790,7 @@ static void kinetis_i2c_setfrequency(struct kinetis_i2cdev_s *priv,
static int kinetis_i2c_start(struct kinetis_i2cdev_s *priv)
{
struct i2c_msg_s *msg;
systime_t start;

i2cinfo("START msg=%p\n", priv->msgs);
msg = priv->msgs;
Expand All @@ -805,9 +806,18 @@ static int kinetis_i2c_start(struct kinetis_i2cdev_s *priv)
}
else
{
/* We are not currently the bus master, so wait for bus ready */
/* We are not currently the bus master, wait for bus ready or timeout */

while (kinetis_i2c_getreg(priv, KINETIS_I2C_S_OFFSET) & I2C_S_BUSY);
start = clock_systimer();

while (kinetis_i2c_getreg(priv, KINETIS_I2C_S_OFFSET) & I2C_S_BUSY)
{
if (clock_systimer() - start > I2C_TIMEOUT)
{
priv->state = STATE_TIMEOUT;
return -EIO;
}
}

/* Become the bus master in transmit mode (send start) */

Expand All @@ -817,13 +827,18 @@ static int kinetis_i2c_start(struct kinetis_i2cdev_s *priv)

if (I2C_M_READ & msg->flags) /* DEBUG: should happen always */
{
/* Wait until start condition establishes control of the bus */
/* Wait until start condition establishes control of the bus or
* a timeout occurs
*/

start = clock_systimer();

while (1)
while ((kinetis_i2c_getreg(priv, KINETIS_I2C_S_OFFSET) & I2C_S_BUSY) == 0)
{
if (kinetis_i2c_getreg(priv, KINETIS_I2C_S_OFFSET) & I2C_S_BUSY)
if (clock_systimer() - start > I2C_TIMEOUT)
{
break;
priv->state = STATE_TIMEOUT;
return -EIO;
}
}
}
Expand Down Expand Up @@ -1167,7 +1182,10 @@ static int kinetis_i2c_transfer(struct i2c_master_s *dev,
{
/* Initiate the transfer, in case restart is required */

kinetis_i2c_start(priv);
if (kinetis_i2c_start(priv) < 0)
{
goto timeout;
}
}

/* Wait for transfer complete */
Expand All @@ -1183,20 +1201,14 @@ static int kinetis_i2c_transfer(struct i2c_master_s *dev,

/* Disable interrupts */

timeout:
kinetis_i2c_putreg(priv, I2C_C1_IICEN, KINETIS_I2C_C1_OFFSET);

/* Release access to I2C bus */

kinetis_i2c_sem_post(priv);

if (priv->state != STATE_OK)
{
return -EIO;
}
else
{
return 0;
}
return (priv->state != STATE_OK) ? -EIO : 0;
}

/************************************************************************************
Expand Down