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stm32: fix I2C waveforms and states

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- most events happen in the first 100us, we don't want to sleep to 2ms.
  This introduces big delays. Just poll the 150us, then fall back to
  sleep.
- restore properly the port state after master transfers.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>

BUG=None
TEST=On Lucas DVT, probe I2C signals with logic analyzer and manually
check them. Verify that the keyboard is still working with the charging
code enabled.

Change-Id: Ic0afde081d070ff6720d924469ecc7166bbc9e4c
Reviewed-on: https://gerrit.chromium.org/gerrit/26161
Commit-Ready: Vincent Palatin <vpalatin@chromium.org>
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
Tested-by: Vincent Palatin <vpalatin@chromium.org>
This commit is contained in:
Vincent Palatin
2012-06-26 23:20:46 +00:00
committed by Gerrit
parent 3a841ae872
commit cbbaf428a9
1 changed files with 17 additions and 7 deletions
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24
chip/stm32/i2c.c
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@@ -235,8 +235,8 @@ static int i2c_init1(void)
/* set clock configuration : standard mode (100kHz) */
STM32_I2C_CCR(I2C1) = I2C_CCR;
/* configuration : I2C mode / Periphal enabled */
STM32_I2C_CR1(I2C1) = (1 << 0);
/* configuration : I2C mode / Periphal enabled, ACK enabled */
STM32_I2C_CR1(I2C1) = (1 << 10) | (1 << 0);
/* error and event interrupts enabled / input clock is 16Mhz */
STM32_I2C_CR2(I2C1) = (1 << 9) | (1 << 8) | 0x10;
@@ -332,8 +332,9 @@ static int wait_status(int port, uint32_t mask)
CPRINTF(" - %016b\n", r);
#endif /* CONFIG_DEBUG_I2C */
return EC_ERROR_TIMEOUT;
} else if (t2.val - t1.val > 150) {
usleep(2000);
}
usleep(2000);
r = STM32_I2C_SR1(port);
}
@@ -353,8 +354,8 @@ static int master_start(int port, int slave_addr)
{
int rv;
/* Change to master send mode, send start bit */
STM32_I2C_CR1(port) |= (1 << 8);
/* 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);
if (rv)
@@ -398,13 +399,19 @@ static void handle_i2c_error(int port, int rv)
t2 = get_time();
if (t2.val - t1.val > 1000000) {
dump_i2c_reg(port);
return;
goto cr_cleanup;
}
/* Send stop */
master_stop(port);
usleep(10000);
r = STM32_I2C_SR2(port);
}
cr_cleanup:
/**
* reset control register to the default state :
* I2C mode / Periphal enabled, ACK enabled
*/
STM32_I2C_CR1(port) = (1 << 10) | (1 << 0);
}
static int i2c_master_transmit(int port, int slave_addr, uint8_t *data,
@@ -428,7 +435,10 @@ static int i2c_master_transmit(int port, int slave_addr, uint8_t *data,
return rv;
STM32_I2C_DR(port) = data[i];
}
rv = wait_status(port, SR1_BTF | SR1_TxE);
rv = wait_status(port, SR1_TxE);
if (rv)
return rv;
rv = wait_status(port, SR1_BTF);
if (rv)
return rv;