scottk/OpenCellular
1
0
Fork 0
mirror of https://github.com/Telecominfraproject/OpenCellular.git synced 2026-01-11 02:15:14 +00:00
Code Issues Packages Projects Releases Wiki Activity

i2c: Display reason for each timeout

Browse Source 
There are a lot of timeous in the i2c driver. When one occurs, print
out the number of it so that the root cause can more easily be
examined.

BUG=chrome-os-partner:10888
TEST=manual:
Lock up the i2c bus from the AP by running the kernel without bus
arbitration doing i2c traffic:

while true; do i2cdump  -f -y 4 0x48; done >/dev/null

and using 'pmu 100' on the EC.

Then see that a timeout error is printed, for example:

i2c wait_status timeout type 2, 101387 us

Change-Id: I3fb3fcf9f07966ef4e71d4358c791fea90aba5d5
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/26830
Reviewed-by: David Hendricks <dhendrix@chromium.org>
This commit is contained in:
Simon Glass
2012-07-05 19:30:34 -07:00
committed by Gerrit
parent 9284cec2fc
commit 0e42faf85b
1 changed files with 31 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files

44
chip/stm32/i2c.c
View File

@@ -321,13 +321,26 @@ static inline void dump_i2c_reg(int port)
#endif /* CONFIG_DEBUG_I2C */
}
static int wait_status(int port, uint32_t mask)
enum wait_t {
WAIT_NONE,
WAIT_MASTER_START,
WAIT_ADDR_READY,
WAIT_XMIT_TXE,
WAIT_XMIT_FINAL_TXE,
WAIT_XMIT_BTF,
WAIT_XMIT_STOP,
WAIT_RX_NE,
WAIT_RX_NE_FINAL,
WAIT_RX_NE_STOP,
WAIT_RX_NE_STOP_SIZE2,
};
static int wait_status(int port, uint32_t mask, enum wait_t wait)
{
uint32_t r;
timestamp_t t1, t2;
t1 = get_time();
t1 = t2 = get_time();
r = STM32_I2C_SR1(port);
while (mask ? ((r & mask) != mask) : r) {
t2 = get_time();
@@ -336,6 +349,8 @@ static int wait_status(int port, uint32_t mask)
CPRINTF(" m %016b\n", mask);
CPRINTF(" - %016b\n", r);
#endif /* CONFIG_DEBUG_I2C */
CPRINTF("i2c wait_status timeout type %d, %d us\n",
wait, (unsigned)t2.val - (unsigned)t1.val);
return EC_ERROR_TIMEOUT;
} else if (t2.val - t1.val > 150) {
usleep(2000);
@@ -343,6 +358,9 @@ static int wait_status(int port, uint32_t mask)
r = STM32_I2C_SR1(port);
}
if (t2.val - t1.val > 1000)
CPRINTF("timeout=%dus\n", (unsigned)t2.val - (unsigned)t1.val);
return EC_SUCCESS;
}
@@ -362,13 +380,13 @@ static int master_start(int port, int slave_addr)
/* Change to master send mode, reset stop bit, send start bit */
STM32_I2C_CR1(port) = (STM32_I2C_CR1(port) & ~(1 << 9)) | (1 << 8);
/* Wait for start bit sent event */
rv = wait_status(port, SR1_SB);
rv = wait_status(port, SR1_SB, WAIT_MASTER_START);
if (rv)
return rv;
/* Send address */
STM32_I2C_DR(port) = slave_addr;
/* Wait for addr ready */
rv = wait_status(port, SR1_ADDR);
rv = wait_status(port, SR1_ADDR, WAIT_ADDR_READY);
if (rv)
return rv;
read_clear_status(port);
@@ -431,21 +449,21 @@ static int i2c_master_transmit(int port, int slave_addr, uint8_t *data,
/* TODO: use common i2c_write_raw instead */
for (i = 0; i < size; i++) {
rv = wait_status(port, SR1_TxE);
rv = wait_status(port, SR1_TxE, WAIT_XMIT_TXE);
if (rv)
return rv;
STM32_I2C_DR(port) = data[i];
}
rv = wait_status(port, SR1_TxE);
rv = wait_status(port, SR1_TxE, WAIT_XMIT_FINAL_TXE);
if (rv)
return rv;
rv = wait_status(port, SR1_BTF);
rv = wait_status(port, SR1_BTF, WAIT_XMIT_BTF);
if (rv)
return rv;
if (stop) {
master_stop(port);
return wait_status(port, 0);
return wait_status(port, 0, WAIT_XMIT_STOP);
}
return EC_SUCCESS;
@@ -483,7 +501,7 @@ static int i2c_master_receive(int port, int slave_addr, uint8_t *data,
if (size >= 2) {
for (i = 0; i < (size - 2); i++) {
rv = wait_status(port, SR1_RxNE);
rv = wait_status(port, SR1_RxNE, WAIT_RX_NE);
if (rv)
return rv;
@@ -500,7 +518,7 @@ static int i2c_master_receive(int port, int slave_addr, uint8_t *data,
* => wait rx ready
* => read [n-1]
*/
rv = wait_status(port, SR1_RxNE);
rv = wait_status(port, SR1_RxNE, WAIT_RX_NE_FINAL);
if (rv)
return rv;
@@ -509,7 +527,7 @@ static int i2c_master_receive(int port, int slave_addr, uint8_t *data,
data[i] = STM32_I2C_DR(port);
rv = wait_status(port, SR1_RxNE);
rv = wait_status(port, SR1_RxNE, WAIT_RX_NE_STOP);
if (rv)
return rv;
@@ -517,7 +535,7 @@ static int i2c_master_receive(int port, int slave_addr, uint8_t *data,
data[i] = STM32_I2C_DR(port);
} else {
master_stop(port);
rv = wait_status(port, SR1_RxNE);
rv = wait_status(port, SR1_RxNE, WAIT_RX_NE_STOP_SIZE2);
if (rv)
return rv;
data[0] = STM32_I2C_DR(port);