coreboot-libre-fam15h-rdimm/3rdparty/chromeec/board/cr50/usb_i2c.c

107 lines
2.5 KiB
C

/* Copyright 2016 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "case_closed_debug.h"
#include "ccd_config.h"
#include "console.h"
#include "gpio.h"
#include "hooks.h"
#include "i2c.h"
#include "rdd.h"
#include "registers.h"
#include "system.h"
#include "timer.h"
#include "usb_i2c.h"
#define CPRINTS(format, args...) cprints(CC_USB, format, ## args)
int usb_i2c_board_is_enabled(void)
{
/* board options use the INA pins as GPIOs */
if (!board_has_ina_support())
return 0;
/*
* Note that this signal requires an external pullup, because this is
* one of the real open drain pins; we cannot pull it up or drive it
* high. On test boards without the pullup, this will mis-detect as
* enabled.
*/
return !gpio_get_level(GPIO_EN_PP3300_INA_L);
}
static void ina_disconnect(void)
{
CPRINTS("I2C disconnect");
/* Disonnect I2C0 SDA/SCL output to B1/B0 pads */
GWRITE(PINMUX, DIOB1_SEL, 0);
GWRITE(PINMUX, DIOB0_SEL, 0);
/* Disconnect B1/B0 pads to I2C0 input SDA/SCL */
GWRITE(PINMUX, I2C0_SDA_SEL, 0);
GWRITE(PINMUX, I2C0_SCL_SEL, 0);
/* Disable power to INA chips */
gpio_set_level(GPIO_EN_PP3300_INA_L, 1);
}
static void ina_connect(void)
{
CPRINTS("I2C connect");
/* Apply power to INA chips */
gpio_set_level(GPIO_EN_PP3300_INA_L, 0);
/*
* Connect B0/B1 pads to I2C0 input SDA/SCL. Note, that the inputs
* for these pads are already enabled for the gpio signals I2C_SCL_INA
* and I2C_SDA_INA in gpio.inc.
*/
GWRITE(PINMUX, I2C0_SDA_SEL, GC_PINMUX_DIOB1_SEL);
GWRITE(PINMUX, I2C0_SCL_SEL, GC_PINMUX_DIOB0_SEL);
/* Connect I2CS SDA/SCL output to B1/B0 pads */
GWRITE(PINMUX, DIOB1_SEL, GC_PINMUX_I2C0_SDA_SEL);
GWRITE(PINMUX, DIOB0_SEL, GC_PINMUX_I2C0_SCL_SEL);
/*
* Initialize the i2cm module after the INAs are powered and the signal
* lines are connected.
*/
i2cm_init();
}
void usb_i2c_board_disable(void)
{
if (!usb_i2c_board_is_enabled())
return;
ina_disconnect();
}
int usb_i2c_board_enable(void)
{
/* board options use the INA pins as GPIOs */
if (!board_has_ina_support())
return EC_SUCCESS;
if (servo_is_connected()) {
CPRINTS("Servo attached; cannot enable I2C");
usb_i2c_board_disable();
return EC_ERROR_BUSY;
}
if (!ccd_ext_is_enabled())
return EC_ERROR_BUSY;
if (!ccd_is_cap_enabled(CCD_CAP_I2C))
return EC_ERROR_ACCESS_DENIED;
if (!usb_i2c_board_is_enabled())
ina_connect();
return EC_SUCCESS;
}