aepko/Ardupilot2
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

HAL_ChibiOS: detect stuck I2C bus and clear with SCL

Browse Source 
This detects the I2C bus becoming stuck with SDA low after a timeout
and clears the bus by toggling SCL. Many thanks to @jhw84 for the
suggestion
This commit is contained in:
Andrew Tridgell 2018-11-15 21:25:29 +11:00
parent a0ed658fcc
commit adf7fefc2e
3 changed files with 50 additions and 32 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

66
libraries/AP_HAL_ChibiOS/I2CDevice.cpp
View File

@ -30,6 +30,8 @@ static const struct I2CInfo {
struct I2CDriver *i2c;
uint8_t dma_channel_rx;
uint8_t dma_channel_tx;
ioline_t scl_line;
ioline_t sda_line;
} I2CD[] = { HAL_I2C_DEVICE_LIST };
using namespace ChibiOS;
@ -51,6 +53,13 @@ I2CBus I2CDeviceManager::businfo[ARRAY_SIZE(I2CD)];
#define HAL_I2C_F7_100_TIMINGR 0x20404768
#define HAL_I2C_F7_400_TIMINGR 0x6000030D
/*
enable clear (toggling SCL) on I2C bus timeouts which leave SDA stuck low
*/
#ifndef HAL_I2C_CLEAR_ON_TIMEOUT
#define HAL_I2C_CLEAR_ON_TIMEOUT 1
#endif
// get a handle for DMA sharing DMA channels with other subsystems
void I2CBus::dma_init(void)
{
@ -63,33 +72,39 @@ void I2CBus::dma_init(void)
// Clear Bus to avoid bus lockup
void I2CBus::clear_all()
{
#if defined(HAL_GPIO_PIN_I2C1_SCL) && defined(HAL_I2C1_SCL_AF)
clear_bus(HAL_GPIO_PIN_I2C1_SCL, HAL_I2C1_SCL_AF);
#endif
#if defined(HAL_GPIO_PIN_I2C2_SCL) && defined(HAL_I2C2_SCL_AF)
clear_bus(HAL_GPIO_PIN_I2C2_SCL, HAL_I2C2_SCL_AF);
#endif
#if defined(HAL_GPIO_PIN_I2C3_SCL) && defined(HAL_I2C3_SCL_AF)
clear_bus(HAL_GPIO_PIN_I2C3_SCL, HAL_I2C3_SCL_AF);
#endif
#if defined(HAL_GPIO_PIN_I2C4_SCL) && defined(HAL_I2C4_SCL_AF)
clear_bus(HAL_GPIO_PIN_I2C4_SCL, HAL_I2C4_SCL_AF);
#endif
for (uint8_t i=0; i<ARRAY_SIZE(I2CD); i++) {
clear_bus(i);
}
}
//This code blocks!
void I2CBus::clear_bus(ioline_t scl_line, uint8_t scl_af)
/*
clear a stuck bus (bus held by a device that is holding SDA low) by
clocking out pulses on SCL to let the device complete its
transaction
*/
void I2CBus::clear_bus(uint8_t busidx)
{
//send dummy clock
palSetLineMode(scl_line, PAL_MODE_OUTPUT_PUSHPULL);
for(int i = 0; i < 20; i++) {
palToggleLine(scl_line);
hal.scheduler->delay_microseconds(200);
const struct I2CInfo &info = I2CD[busidx];
const iomode_t mode_saved = palReadLineMode(info.scl_line);
palSetLineMode(info.scl_line, PAL_MODE_OUTPUT_PUSHPULL);
for(uint8_t j = 0; j < 20; j++) {
palToggleLine(info.scl_line);
hal.scheduler->delay_microseconds(10);
}
palSetLineMode(scl_line, PAL_MODE_ALTERNATE(scl_af) | PAL_STM32_OSPEED_MID2 | PAL_STM32_OTYPE_OPENDRAIN);
palSetLineMode(info.scl_line, mode_saved);
}
/*
read SDA on a bus, to check if it may be stuck
*/
uint8_t I2CBus::read_sda(uint8_t busidx)
{
const struct I2CInfo &info = I2CD[busidx];
const iomode_t mode_saved = palReadLineMode(info.sda_line);
palSetLineMode(info.sda_line, PAL_MODE_INPUT);
uint8_t ret = palReadLine(info.sda_line);
palSetLineMode(info.sda_line, mode_saved);
return ret;
}
// setup I2C buses
@ -260,6 +275,11 @@ bool I2CDevice::_transfer(const uint8_t *send, uint32_t send_len,
i2cReleaseBus(I2CD[bus.busnum].i2c);
return true;
}
#if HAL_I2C_CLEAR_ON_TIMEOUT
if (ret == MSG_TIMEOUT && I2CBus::read_sda(bus.busnum) == 0) {
I2CBus::clear_bus(bus.busnum);
}
#endif
}
bus.bouncebuffer_finish(send, recv, recv_len);
i2cReleaseBus(I2CD[bus.busnum].i2c);

3
libraries/AP_HAL_ChibiOS/I2CDevice.h
View File

@ -50,7 +50,8 @@ public:
void dma_deallocate(Shared_DMA *);
void dma_init(void);
static void clear_all(void);
static void clear_bus(ioline_t scl_line, uint8_t scl_af);
static void clear_bus(uint8_t busidx);
static uint8_t read_sda(uint8_t busidx);
};
class I2CDevice : public AP_HAL::I2CDevice {

13
libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py
View File

@ -872,6 +872,8 @@ def write_I2C_config(f):
if len(i2c_list) == 0:
error("I2C_ORDER invalid")
devlist = []
# write out config structures
for dev in i2c_list:
if not dev.startswith('I2C') or dev[3] not in "1234":
error("Bad I2C_ORDER element %s" % dev)
@ -879,17 +881,12 @@ def write_I2C_config(f):
devlist.append('HAL_I2C%u_CONFIG' % n)
f.write('''
#if defined(STM32_I2C_I2C%u_RX_DMA_STREAM) && defined(STM32_I2C_I2C%u_TX_DMA_STREAM)
#define HAL_I2C%u_CONFIG { &I2CD%u, STM32_I2C_I2C%u_RX_DMA_STREAM, STM32_I2C_I2C%u_TX_DMA_STREAM }
#define HAL_I2C%u_CONFIG { &I2CD%u, STM32_I2C_I2C%u_RX_DMA_STREAM, STM32_I2C_I2C%u_TX_DMA_STREAM, HAL_GPIO_PIN_I2C%u_SCL, HAL_GPIO_PIN_I2C%u_SDA }
#else
#define HAL_I2C%u_CONFIG { &I2CD%u, SHARED_DMA_NONE, SHARED_DMA_NONE }
#define HAL_I2C%u_CONFIG { &I2CD%u, SHARED_DMA_NONE, SHARED_DMA_NONE, HAL_GPIO_PIN_I2C%u_SCL, HAL_GPIO_PIN_I2C%u_SDA }
#endif
'''
% (n, n, n, n, n, n, n, n))
if dev + "_SCL" in bylabel:
p = bylabel[dev + "_SCL"]
f.write(
'#define HAL_%s_SCL_AF %d\n' % (dev, p.af)
)
% (n, n, n, n, n, n, n, n, n, n, n, n))
f.write('\n#define HAL_I2C_DEVICE_LIST %s\n\n' % ','.join(devlist))
def parse_timer(str):