1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
|
/* Copyright 2020 The ChromiumOS Authors
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*
* Parade PS8740 (and PS8742)
* USB Type-C Redriving Switch for USB Host / DisplayPort.
*/
#include "common.h"
#include "i2c.h"
#include "ps8740.h"
#include "usb_mux.h"
#include "util.h"
int ps8740_read(const struct usb_mux *me, uint8_t reg, int *val)
{
return i2c_read8(me->i2c_port, me->i2c_addr_flags, reg, val);
}
int ps8740_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 ps8740_init(const struct usb_mux *me)
{
int id1;
int id2;
int res;
/* Reset chip back to power-on state */
res = ps8740_write(me, PS8740_REG_MODE, PS8740_MODE_POWER_DOWN);
if (res)
return res;
/*
* Verify chip ID registers.
*/
res = ps8740_read(me, PS8740_REG_CHIP_ID1, &id1);
if (res)
return res;
res = ps8740_read(me, PS8740_REG_CHIP_ID2, &id2);
if (res)
return res;
if (id1 != PS8740_CHIP_ID1 || id2 != PS8740_CHIP_ID2)
return EC_ERROR_UNKNOWN;
/*
* Verify revision ID registers.
*/
res = ps8740_read(me, PS8740_REG_REVISION_ID1, &id1);
if (res)
return res;
res = ps8740_read(me, PS8740_REG_REVISION_ID2, &id2);
if (res)
return res;
if (id1 != PS8740_REVISION_ID1)
return EC_ERROR_UNKNOWN;
/* PS8740 may have REVISION_ID2 as 0xa or 0xb */
if (id2 != PS8740_REVISION_ID2_0 && id2 != PS8740_REVISION_ID2_1)
return EC_ERROR_UNKNOWN;
return EC_SUCCESS;
}
/* Writes control register to set switch mode */
static int ps8740_set_mux(const struct usb_mux *me, mux_state_t mux_state,
bool *ack_required)
{
uint8_t reg = 0;
/* This driver does not use host command ACKs */
*ack_required = false;
/* This driver treats safe mode as none */
if (mux_state & USB_PD_MUX_SAFE_MODE)
mux_state = USB_PD_MUX_NONE;
if (mux_state & USB_PD_MUX_USB_ENABLED)
reg |= PS8740_MODE_USB_ENABLED;
if (mux_state & USB_PD_MUX_DP_ENABLED)
reg |= PS8740_MODE_DP_ENABLED;
if (mux_state & USB_PD_MUX_POLARITY_INVERTED)
reg |= PS8740_MODE_POLARITY_INVERTED;
return ps8740_write(me, PS8740_REG_MODE, reg);
}
/* Reads control register and updates mux_state accordingly */
static int ps8740_get_mux(const struct usb_mux *me, mux_state_t *mux_state)
{
int reg;
int res;
res = ps8740_read(me, PS8740_REG_STATUS, ®);
if (res)
return res;
*mux_state = 0;
if (reg & PS8740_STATUS_USB_ENABLED)
*mux_state |= USB_PD_MUX_USB_ENABLED;
if (reg & PS8740_STATUS_DP_ENABLED)
*mux_state |= USB_PD_MUX_DP_ENABLED;
if (reg & PS8740_STATUS_POLARITY_INVERTED)
*mux_state |= USB_PD_MUX_POLARITY_INVERTED;
return EC_SUCCESS;
}
/* Tune USB Tx/Rx Equalization */
int ps8740_tune_usb_eq(const struct usb_mux *me, uint8_t tx, uint8_t rx)
{
int ret;
ret = ps8740_write(me, PS8740_REG_USB_EQ_TX, tx);
ret |= ps8740_write(me, 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,
};
|
