diff options
Diffstat (limited to 'chip/lm4/i2c.c')
| -rw-r--r-- | chip/lm4/i2c.c | 30 |
1 files changed, 21 insertions, 9 deletions
diff --git a/chip/lm4/i2c.c b/chip/lm4/i2c.c index 7ca195f587..a789478e4b 100644 --- a/chip/lm4/i2c.c +++ b/chip/lm4/i2c.c @@ -85,7 +85,7 @@ static int wait_idle(int port) task_set_event(task_get_current(), event, 0); /* Check for errors */ - if (i & LM4_I2C_MCS_ERROR) + if (i & (LM4_I2C_MCS_CLKTO | LM4_I2C_MCS_ARBLST | LM4_I2C_MCS_ERROR)) return EC_ERROR_UNKNOWN; return EC_SUCCESS; @@ -108,15 +108,27 @@ static int i2c_transmit_receive(int port, int slave_addr, if (transmit_size == 0 && receive_size == 0) return EC_SUCCESS; - if (!started && (LM4_I2C_MCS(port) & - (LM4_I2C_MCS_CLKTO | LM4_I2C_MCS_BUSBSY))) { + reg_mcs = LM4_I2C_MCS(port); + if (!started && (reg_mcs & (LM4_I2C_MCS_CLKTO | LM4_I2C_MCS_ARBLST))) { + uint32_t tpr = LM4_I2C_MTPR(port); + + CPRINTF("[%T I2C%d bad status 0x%02x]\n", port, reg_mcs); + + /* Clock timeout or arbitration lost. Reset port to clear. */ + LM4_SYSTEM_SRI2C |= (1 << port); + clock_wait_cycles(3); + LM4_SYSTEM_SRI2C &= ~(1 << port); + clock_wait_cycles(3); + + /* Restore settings */ + LM4_I2C_MCR(port) = 0x10; + LM4_I2C_MTPR(port) = tpr; + /* - * Previous clock timeout or bus-busy. Bounce the master to - * clear these error states. + * We don't know what edges the slave saw, so sleep long enough + * that the slave will see the new start condition below. */ - LM4_I2C_MCR(port) = 0; - usleep(100000); - LM4_I2C_MCR(port) = 0x10; + usleep(1000); } if (transmit_data) { @@ -184,7 +196,7 @@ static int i2c_transmit_receive(int port, int slave_addr, } /* Check for error conditions */ - if (LM4_I2C_MCS(port) & (LM4_I2C_MCS_CLKTO | LM4_I2C_MCS_BUSBSY | + if (LM4_I2C_MCS(port) & (LM4_I2C_MCS_CLKTO | LM4_I2C_MCS_ARBLST | LM4_I2C_MCS_ERROR)) return EC_ERROR_UNKNOWN; |