coreboot-libre-fam15h-rdimm/3rdparty/chromeec/driver/usb_mux/ps874x.c

128 lines
2.9 KiB
C

/* Copyright 2017 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.
*
* Parade PS874X USB Type-C Redriving Switch for USB Host / DisplayPort.
*/
#include "common.h"
#include "i2c.h"
#include "ps874x.h"
#include "usb_mux.h"
#include "util.h"
static inline int ps874x_read(int port, uint8_t reg, int *val)
{
return i2c_read8(I2C_PORT_USB_MUX, MUX_ADDR(port),
reg, val);
}
static inline int ps874x_write(int port, uint8_t reg, uint8_t val)
{
return i2c_write8(I2C_PORT_USB_MUX, MUX_ADDR(port),
reg, val);
}
static int ps874x_init(int port)
{
int val;
int res;
/* Reset chip back to power-on state */
res = ps874x_write(port, PS874X_REG_MODE, PS874X_MODE_POWER_DOWN);
if (res)
return res;
/*
* Verify revision / chip ID registers.
*/
res = ps874x_read(port, PS874X_REG_REVISION_ID1, &val);
if (res)
return res;
#ifdef CONFIG_USB_MUX_PS8743
/*
* From Parade: PS8743 may have REVISION_ID1 as 0 or 1
* Rev 1 is derived from Rev 0 and have same functionality.
*/
if (val != PS874X_REVISION_ID1_0 && val != PS874X_REVISION_ID1_1)
return EC_ERROR_UNKNOWN;
#else
if (val != PS874X_REVISION_ID1)
return EC_ERROR_UNKNOWN;
#endif
res = ps874x_read(port, PS874X_REG_REVISION_ID2, &val);
if (res)
return res;
if (val != PS874X_REVISION_ID2)
return EC_ERROR_UNKNOWN;
res = ps874x_read(port, PS874X_REG_CHIP_ID1, &val);
if (res)
return res;
if (val != PS874X_CHIP_ID1)
return EC_ERROR_UNKNOWN;
res = ps874x_read(port, PS874X_REG_CHIP_ID2, &val);
if (res)
return res;
if (val != PS874X_CHIP_ID2)
return EC_ERROR_UNKNOWN;
return EC_SUCCESS;
}
/* Writes control register to set switch mode */
static int ps874x_set_mux(int port, mux_state_t mux_state)
{
uint8_t reg = 0;
if (mux_state & MUX_USB_ENABLED)
reg |= PS874X_MODE_USB_ENABLED;
if (mux_state & MUX_DP_ENABLED)
reg |= PS874X_MODE_DP_ENABLED;
if (mux_state & MUX_POLARITY_INVERTED)
reg |= PS874X_MODE_POLARITY_INVERTED;
return ps874x_write(port, PS874X_REG_MODE, reg);
}
/* Reads control register and updates mux_state accordingly */
static int ps874x_get_mux(int port, mux_state_t *mux_state)
{
int reg;
int res;
res = ps874x_read(port, PS874X_REG_STATUS, &reg);
if (res)
return res;
*mux_state = 0;
if (reg & PS874X_STATUS_USB_ENABLED)
*mux_state |= MUX_USB_ENABLED;
if (reg & PS874X_STATUS_DP_ENABLED)
*mux_state |= MUX_DP_ENABLED;
if (reg & PS874X_STATUS_POLARITY_INVERTED)
*mux_state |= MUX_POLARITY_INVERTED;
return EC_SUCCESS;
}
/* Tune USB Tx/Rx Equalization */
int ps874x_tune_usb_eq(int port, uint8_t tx, uint8_t rx)
{
int ret;
ret = ps874x_write(port, PS874X_REG_USB_EQ_TX, tx);
ret |= ps874x_write(port, PS874X_REG_USB_EQ_RX, rx);
return ret;
}
const struct usb_mux_driver ps874x_usb_mux_driver = {
.init = ps874x_init,
.set = ps874x_set_mux,
.get = ps874x_get_mux,
};