cr50: Have INAs and I2Cm enabled when rdd is attached

The INAs are only used for development and testing
purposes. Therefore, the 3.3V rail to the INAs is off by default and
the I2Cm module is not enabled. Enabling INA power and connecting the
I2Cm module was done at the beginning of each USB to I2C request. The
problem with this approach is that INA measurments didn't always
succeed due to not enough time for the INAs to initialize.

Rather than add some arbitrary delay, it is better to tie the INAs to
when rdd is attached/detached. It is only when rdd is attached that
the INAs will be accessed, so there is no need to enable/disable for
each individual I2C transaction.

This CL ties the enabling/disabling of the INA and I2Cm module to the
rdd state. This change makes the previous use of
usb_i2c_board_enable() and usb_i2c_board_disable() obslete.

BRANCH=none
BUG=chrome-os-partner:62375
TEST=manual
Connect servo with suzyq connected:
sudo servod -p 0x5014 -b eve -c eve_r0_inas.xml
Then execute single INA reads dut-control pp3300_dx_edp_mv and verify
that it returns meaningful numbers. Without this CL single reads via
dut-control would always return 0.

Change-Id: I799552bfd0701efd1828a0d720ac2a6cedee5ca1
Signed-off-by: Scott <scollyer@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/436864
Commit-Ready: Scott Collyer <scollyer@chromium.org>
Tested-by: Scott Collyer <scollyer@chromium.org>
Reviewed-by: Mary Ruthven <mruthven@chromium.org>

1 files changed, 5 insertions, 11 deletions

diff --git a/board/cr50/usb_i2c.c b/board/cr50/usb_i2c.c
index 8ba90c5f63..786a886c7f 100644
--- a/board/cr50/usb_i2c.c
+++ b/board/cr50/usb_i2c.c
@@ -35,7 +35,6 @@ static void ina_disconnect(void)
 	/* Disable power to INA chips */
 	gpio_set_level(GPIO_EN_PP3300_INA_L, 1);
 }
-DECLARE_DEFERRED(ina_disconnect);
 
 static void ina_connect(void)
 {
@@ -65,29 +64,24 @@ static void ina_connect(void)
 	i2cm_init();
 }
 
-void usb_i2c_board_disable(int debounce)
+void usb_i2c_board_disable(void)
 {
 	if (!i2c_enabled())
 		return;
 
-	/*
-	 * Wait to disable i2c in case we are doing a bunch of i2c transactions
-	 * in a row.
-	 */
-	hook_call_deferred(&ina_disconnect_data, debounce ? 1 * SECOND : 0);
+	ina_disconnect();
 }
 
 int usb_i2c_board_enable(void)
 {
-	if (device_get_state(DEVICE_SERVO) != DEVICE_STATE_OFF) {
+	if (device_get_state(DEVICE_SERVO) == DEVICE_STATE_ON) {
 		CPRINTS("Servo is attached I2C cannot be enabled");
-		usb_i2c_board_disable(0);
+		usb_i2c_board_disable();
 		return EC_ERROR_BUSY;
 	}
 
-	hook_call_deferred(&ina_disconnect_data, -1);
-
 	if (!i2c_enabled())
 		ina_connect();
+
 	return EC_SUCCESS;
 }