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/* Copyright 2015 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 PS8740 USB port switch driver.
*/
#include "common.h"
#include "i2c.h"
#include "ps8740.h"
#include "usb_mux.h"
#include "util.h"
static int ps8740_read(int i2c_addr, uint8_t reg, uint8_t *val)
{
int read, res;
res = i2c_read8(I2C_PORT_USB_MUX, i2c_addr, reg, &read);
if (res)
return res;
*val = read;
return EC_SUCCESS;
}
static int ps8740_write(int i2c_addr, uint8_t reg, uint8_t val)
{
return i2c_write8(I2C_PORT_USB_MUX, i2c_addr, reg, val);
}
static int ps8740_reset(int i2c_addr)
{
return ps8740_write(i2c_addr, PS8740_REG_MODE, PS8740_MODE_POWER_DOWN);
}
static int ps8740_init(int i2c_addr)
{
uint8_t val;
int res;
/* Reset chip back to power-on state */
res = ps8740_reset(i2c_addr);
if (res)
return res;
/* Verify revision / chip ID registers */
res = ps8740_read(i2c_addr, PS8740_REG_REVISION_ID1, &val);
if (res)
return res;
if (val != PS8740_REVISION_ID1)
return EC_ERROR_UNKNOWN;
res = ps8740_read(i2c_addr, PS8740_REG_REVISION_ID2, &val);
if (res)
return res;
if (val < PS8740_REVISION_ID2)
return EC_ERROR_UNKNOWN;
res = ps8740_read(i2c_addr, PS8740_REG_CHIP_ID1, &val);
if (res)
return res;
if (val != PS8740_CHIP_ID1)
return EC_ERROR_UNKNOWN;
res = ps8740_read(i2c_addr, PS8740_REG_CHIP_ID2, &val);
if (res)
return res;
if (val != PS8740_CHIP_ID2)
return EC_ERROR_UNKNOWN;
return EC_SUCCESS;
}
/* Writes control register to set switch mode */
static int ps8740_set_mux(int i2c_addr, mux_state_t mux_state)
{
uint8_t reg = 0;
if (mux_state & MUX_USB_ENABLED)
reg |= PS8740_MODE_USB_ENABLED;
if (mux_state & MUX_DP_ENABLED)
reg |= PS8740_MODE_DP_ENABLED;
if (mux_state & MUX_POLARITY_INVERTED)
reg |= PS8740_MODE_POLARITY_INVERTED;
return ps8740_write(i2c_addr, PS8740_REG_MODE, reg);
}
/* Reads control register and updates mux_state accordingly */
static int ps8740_get_mux(int i2c_addr, mux_state_t *mux_state)
{
uint8_t reg;
int res;
*mux_state = 0;
res = ps8740_read(i2c_addr, PS8740_REG_STATUS, ®);
if (res)
return res;
if (reg & PS8740_STATUS_USB_ENABLED)
*mux_state |= MUX_USB_ENABLED;
if (reg & PS8740_STATUS_DP_ENABLED)
*mux_state |= MUX_DP_ENABLED;
if (reg & PS8740_STATUS_POLARITY_INVERTED)
*mux_state |= MUX_POLARITY_INVERTED;
return EC_SUCCESS;
}
/* Tune USB Tx/Rx Equalization */
int ps8740_tune_usb_eq(int i2c_addr, uint8_t tx, uint8_t rx)
{
int ret = 0;
ret |= ps8740_write(i2c_addr, PS8740_REG_USB_EQ_TX, tx);
ret |= ps8740_write(i2c_addr, PS8740_REG_USB_EQ_RX, rx);
return ret;
}
const struct usb_mux_driver ps8740_usb_mux_driver = {
.init = ps8740_init,
.set = ps8740_set_mux,
.get = ps8740_get_mux,
};
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