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@DanielLockau-MLPA
DanielLockau-MLPA committed Aug 27, 2024
1 parent 5ca39b4 commit b0e02ff
Showing 1 changed file with 53 additions and 76 deletions.
129 changes: 53 additions & 76 deletions cpu/sam0_common/periph/i2c.c
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Original file line number Diff line number Diff line change
Expand Up @@ -51,7 +51,7 @@
#define SERCOM_I2CM_CTRLA_MODE_I2C_MASTER SERCOM_I2CM_CTRLA_MODE(5)
#endif

static int _i2c_start(SercomI2cm *dev, uint16_t addr);
static int _i2c_start(i2c_t dev_id, uint16_t addr);
static inline int _write(SercomI2cm *dev, const uint8_t *data, size_t length,
uint8_t stop);
static inline int _read(SercomI2cm *dev, uint8_t *data, size_t length,
Expand All @@ -75,17 +75,6 @@ static inline SercomI2cm *bus(i2c_t dev)
return i2c_config[dev].dev;
}

static inline const i2c_conf_t *config(SercomI2cm *dev)
{
for (unsigned i = 0; i < I2C_NUMOF; i++) {
if (i2c_config[i].dev == dev) {
return &i2c_config[i];
}
}

return NULL;
}

static void _syncbusy(SercomI2cm *dev)
{
#ifdef SERCOM_I2CM_STATUS_SYNCBUSY
Expand Down Expand Up @@ -121,12 +110,9 @@ static void _reset(SercomI2cm *dev)
* @return true if bus was not blocked or successfully unblocked,
* false otherwise
*/
static bool _check_and_unblock_bus(const i2c_conf_t *dev_conf, bool initialized)
static bool _check_and_unblock_bus(i2c_t dev_id, bool initialized)
{
assert(dev_conf != NULL);

unsigned dev_num = ((uintptr_t)dev_conf - (uintptr_t)i2c_config) / sizeof(i2c_conf_t);
(void) dev_num; /* only required for debug output */
const i2c_conf_t *dev_conf = &i2c_config[dev_id];

/* reconfigure pins to gpio for testing */
gpio_disable_mux(dev_conf->sda_pin);
Expand All @@ -139,11 +125,11 @@ static bool _check_and_unblock_bus(const i2c_conf_t *dev_conf, bool initialized)
if (!gpio_read(dev_conf->sda_pin)) {
printf("i2c.c: i2c bus hangup detected for bus #%u"
" with configuration at 0x%08"PRIx32", recovering...\n",
dev_num, (uint32_t)dev_conf);
dev_id, (uint32_t)dev_conf);
}
else {
printf("i2c.c: i2c bus #%u with configuration at"
" 0x%08"PRIx32" is ok\n", dev_num, (uint32_t)dev_conf);
" 0x%08"PRIx32" is ok\n", dev_id, (uint32_t)dev_conf);
}
}

Expand All @@ -165,7 +151,7 @@ static bool _check_and_unblock_bus(const i2c_conf_t *dev_conf, bool initialized)
bool success = !!gpio_read(dev_conf->sda_pin);

if (IS_ACTIVE(ENABLE_DEBUG) && !success) {
DEBUG("i2c.c: i2c recovery failed for bus #%u\n", dev_num);
DEBUG("i2c.c: i2c recovery failed for bus #%u\n", dev_id);
}

if (initialized) {
Expand All @@ -192,7 +178,7 @@ void i2c_init(i2c_t dev)
const uint32_t fGCLK = sam0_gclk_freq(i2c_config[dev].gclk_src);

/* initial check if bus is blocked & resolve attempt */
if (!_check_and_unblock_bus(&i2c_config[dev], false)) {
if (!_check_and_unblock_bus(dev, false)) {
DEBUG("i2c.c: bus #%u is blocked - init will continue\n", dev);
}

Expand Down Expand Up @@ -340,7 +326,7 @@ int i2c_read_bytes(i2c_t dev, uint16_t addr,

if (!(flags & I2C_NOSTART)) {
/* start transmission and send slave address */
ret = _i2c_start(bus(dev), (addr << 1) | I2C_READ);
ret = _i2c_start(dev, (addr << 1) | I2C_READ);
if (ret < 0) {
DEBUG("Start command failed\n");
return ret;
Expand Down Expand Up @@ -381,7 +367,7 @@ int i2c_write_bytes(i2c_t dev, uint16_t addr, const void *data, size_t len,
}

if (!(flags & I2C_NOSTART)) {
ret = _i2c_start(bus(dev), (addr<<1));
ret = _i2c_start(dev, (addr<<1));
if (ret < 0) {
DEBUG("Start command failed\n");
return ret;
Expand Down Expand Up @@ -418,8 +404,10 @@ void _i2c_poweroff(i2c_t dev)
_syncbusy(bus(dev));
}

static int _i2c_start(SercomI2cm *dev, uint16_t addr)
static int _i2c_start(i2c_t dev_id, uint16_t addr)
{
SercomI2cm *dev = bus(dev_id);

/* Wait for hardware module to sync */
DEBUG_PUTS("i2c.c: Wait for device to be ready");
_syncbusy(dev);
Expand Down Expand Up @@ -453,7 +441,7 @@ static int _i2c_start(SercomI2cm *dev, uint16_t addr)
*
* We further generally check for BUSERR and unexpected bus states.
*
* We ignore dev->INTFLAG.bit.ERROR altogehter as it does not
* We ignore dev->INTFLAG.bit.ERROR altogether as it does not
* seem to get set in the current configuration of the SERCOM module
* (this finding applies to SAME54 / SAMD51 devices).
*
Expand All @@ -466,62 +454,51 @@ static int _i2c_start(SercomI2cm *dev, uint16_t addr)
*/
uint16_t intflag = dev->INTFLAG.reg;
uint16_t status = dev->STATUS.reg;
bool any_error = res ||
(
(intflag & SERCOM_I2CM_INTFLAG_MB) &&
(status & (SERCOM_I2CM_STATUS_ARBLOST | SERCOM_I2CM_STATUS_RXNACK))
) || (
status & SERCOM_I2CM_STATUS_BUSERR
) || (
(status & SERCOM_I2CM_STATUS_BUSSTATE_Msk) == BUSSTATE_UNKNOWN
) || (
(status & SERCOM_I2CM_STATUS_BUSSTATE_Msk) == BUSSTATE_BUSY
);

/* handle errors */
if (any_error) {
bool unblock_bus = false;
bool unblock_bus = false;

DEBUG("i2c.c: error: res=%d, INTFLAG=0x%04"PRIx16", STATUS=0x%04"PRIx16"\n",
res, dev->INTFLAG.reg, dev->STATUS.reg);
if (res) {
DEBUG_PUTS("i2c.c: STATUS_ERR_TIMEOUT");
unblock_bus = true;
}
else if ((status & SERCOM_I2CM_STATUS_BUSSTATE_Msk) == BUSSTATE_BUSY) {
DEBUG_PUTS("i2c.c: STATUS_ERR_BUS_BUSY");
unblock_bus = true;
res = -EAGAIN;
}
else if ((status & SERCOM_I2CM_STATUS_BUSSTATE_Msk) == BUSSTATE_UNKNOWN) {
DEBUG_PUTS("i2c.c: STATUS_ERR_BUS_STATE_UNKNOWN");
unblock_bus = true;
res = -EIO;
}
else if ((intflag & SERCOM_I2CM_INTFLAG_MB) &&
(status & SERCOM_I2CM_STATUS_ARBLOST)) {
DEBUG_PUTS("i2c.c: STATUS_ERR_ARBLOST");
res = -EAGAIN;
}
else if (status & SERCOM_I2CM_STATUS_BUSERR) {
/* a bus error not related to a lost arbitration */
DEBUG_PUTS("i2c.c: STATUS_ERR_BUSERR");
unblock_bus = true;
res = -EIO;
}
else if ((intflag & SERCOM_I2CM_INTFLAG_MB) &&
(status & SERCOM_I2CM_STATUS_RXNACK)) {
/* datasheet recommends: send ack + stop condition */
dev->CTRLB.reg |= SERCOM_I2CM_CTRLB_CMD(3);
_syncbusy(dev);
DEBUG_PUTS("i2c.c: STATUS_ERR_BUSY_OR_BAD_ADDRESS");
res = -ENXIO;
}

if (res) {
DEBUG_PUTS("i2c.c: STATUS_ERR_TIMEOUT");
unblock_bus = true;
}
else if ((status & SERCOM_I2CM_STATUS_BUSSTATE_Msk) & BUSSTATE_BUSY) {
DEBUG_PUTS("i2c.c: STATUS_ERR_BUS_BUSY");
unblock_bus = true;
res = -EAGAIN;
}
else if ((status & SERCOM_I2CM_STATUS_BUSSTATE_Msk) & BUSSTATE_UNKNOWN) {
DEBUG_PUTS("i2c.c: STATUS_ERR_BUS_STATE_UNKNOWN");
unblock_bus = true;
res = -EIO;
}
else if ((intflag & SERCOM_I2CM_INTFLAG_MB) &&
(status & SERCOM_I2CM_STATUS_ARBLOST)) {
DEBUG_PUTS("i2c.c: STATUS_ERR_ARBLOST");
res = -EAGAIN;
}
else if (status & SERCOM_I2CM_STATUS_BUSERR) {
/* a bus error not related to a lost arbitration */
DEBUG_PUTS("i2c.c: STATUS_ERR_BUSERR");
unblock_bus = true;
res = -EIO;
}
else if ((intflag & SERCOM_I2CM_INTFLAG_MB) &&
(status & SERCOM_I2CM_STATUS_RXNACK)) {
/* datasheet recommends: send ack + stop condition */
dev->CTRLB.reg |= SERCOM_I2CM_CTRLB_CMD(3);
_syncbusy(dev);
DEBUG_PUTS("i2c.c: STATUS_ERR_BUSY_OR_BAD_ADDRESS");
res = -ENXIO;
}
if (IS_ACTIVE(ENABLE_DEBUG) && res) {
DEBUG("i2c.c: error: res=%d, INTFLAG=0x%04"PRIx16", STATUS=0x%04"PRIx16"\n",
res, dev->INTFLAG.reg, dev->STATUS.reg);
}

if (unblock_bus) {
_check_and_unblock_bus(config(dev), true);
}
if (unblock_bus) {
_check_and_unblock_bus(dev_id, true);
}

/* Reset flags */
Expand Down

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