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/* Copyright 2021 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 PS8822
* USB Type-C Redriving Switch for USB Host / DisplayPort.
*/
#include "common.h"
#include "i2c.h"
#include "ps8822.h"
#include "usb_mux.h"
#include "util.h"
static int ps8822_read(const struct usb_mux *me, uint8_t reg, int *val)
{
return i2c_read8(me->i2c_port, me->i2c_addr_flags,
reg, val);
}
static int ps8822_write(const struct usb_mux *me, uint8_t reg, uint8_t val)
{
return i2c_write8(me->i2c_port, me->i2c_addr_flags,
reg, val);
}
static int ps8822_init(const struct usb_mux *me)
{
char id[PS8822_ID_LEN + 1];
int reg;
int i;
int rv = 0;
/* Read ID registers */
for (i = 0; i < PS8822_ID_LEN; i++) {
rv |= ps8822_read(me, PS8822_REG_DEV_ID1 + i, ®);
if (!rv)
id[i] = reg;
}
if (!rv) {
id[PS8822_ID_LEN] = '\0';
/* Set mode register to default value */
rv = ps8822_write(me, PS8822_REG_MODE, 0);
rv |= strcasecmp("PS8822", id);
}
return rv;
}
/* Writes control register to set switch mode */
static int ps8822_set_mux(const struct usb_mux *me, mux_state_t mux_state)
{
int reg;
int rv;
rv = ps8822_read(me, PS8822_REG_MODE, ®);
if (rv)
return rv;
/* Assume standby, preserve PIN_E config bit */
reg &= ~(PS8822_MODE_ALT_DP_EN | PS8822_MODE_USB_EN | PS8822_MODE_FLIP);
if (mux_state & USB_PD_MUX_USB_ENABLED)
reg |= PS8822_MODE_USB_EN;
if (mux_state & USB_PD_MUX_DP_ENABLED)
reg |= PS8822_MODE_ALT_DP_EN;
if (mux_state & USB_PD_MUX_POLARITY_INVERTED)
reg |= PS8822_MODE_FLIP;
return ps8822_write(me, PS8822_REG_MODE, reg);
}
/* Reads control register and updates mux_state accordingly */
static int ps8822_get_mux(const struct usb_mux *me, mux_state_t *mux_state)
{
int reg;
int res;
res = ps8822_read(me, PS8822_REG_MODE, ®);
if (res)
return res;
*mux_state = 0;
if (reg & PS8822_MODE_USB_EN)
*mux_state |= USB_PD_MUX_USB_ENABLED;
if (reg & PS8822_MODE_ALT_DP_EN)
*mux_state |= USB_PD_MUX_DP_ENABLED;
if (reg & PS8822_MODE_FLIP)
*mux_state |= USB_PD_MUX_POLARITY_INVERTED;
return EC_SUCCESS;
}
const struct usb_mux_driver ps8822_usb_mux_driver = {
.init = ps8822_init,
.set = ps8822_set_mux,
.get = ps8822_get_mux,
};
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