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
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright © 2006-2007 Intel Corporation
*
* Authors:
* Eric Anholt <eric@anholt.net>
*/
#include <linux/export.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-bit.h>
#include "psb_drv.h"
#include "psb_intel_reg.h"
/*
* Intel GPIO access functions
*/
#define I2C_RISEFALL_TIME 20
static int get_clock(void *data)
{
struct psb_intel_i2c_chan *chan = data;
struct drm_device *dev = chan->drm_dev;
u32 val;
val = REG_READ(chan->reg);
return (val & GPIO_CLOCK_VAL_IN) != 0;
}
static int get_data(void *data)
{
struct psb_intel_i2c_chan *chan = data;
struct drm_device *dev = chan->drm_dev;
u32 val;
val = REG_READ(chan->reg);
return (val & GPIO_DATA_VAL_IN) != 0;
}
static void set_clock(void *data, int state_high)
{
struct psb_intel_i2c_chan *chan = data;
struct drm_device *dev = chan->drm_dev;
u32 reserved = 0, clock_bits;
/* On most chips, these bits must be preserved in software. */
reserved =
REG_READ(chan->reg) & (GPIO_DATA_PULLUP_DISABLE |
GPIO_CLOCK_PULLUP_DISABLE);
if (state_high)
clock_bits = GPIO_CLOCK_DIR_IN | GPIO_CLOCK_DIR_MASK;
else
clock_bits = GPIO_CLOCK_DIR_OUT | GPIO_CLOCK_DIR_MASK |
GPIO_CLOCK_VAL_MASK;
REG_WRITE(chan->reg, reserved | clock_bits);
udelay(I2C_RISEFALL_TIME); /* wait for the line to change state */
}
static void set_data(void *data, int state_high)
{
struct psb_intel_i2c_chan *chan = data;
struct drm_device *dev = chan->drm_dev;
u32 reserved = 0, data_bits;
/* On most chips, these bits must be preserved in software. */
reserved =
REG_READ(chan->reg) & (GPIO_DATA_PULLUP_DISABLE |
GPIO_CLOCK_PULLUP_DISABLE);
if (state_high)
data_bits = GPIO_DATA_DIR_IN | GPIO_DATA_DIR_MASK;
else
data_bits =
GPIO_DATA_DIR_OUT | GPIO_DATA_DIR_MASK |
GPIO_DATA_VAL_MASK;
REG_WRITE(chan->reg, reserved | data_bits);
udelay(I2C_RISEFALL_TIME); /* wait for the line to change state */
}
/**
* psb_intel_i2c_create - instantiate an Intel i2c bus using the specified GPIO reg
* @dev: DRM device
* @output: driver specific output device
* @reg: GPIO reg to use
* @name: name for this bus
*
* Creates and registers a new i2c bus with the Linux i2c layer, for use
* in output probing and control (e.g. DDC or SDVO control functions).
*
* Possible values for @reg include:
* %GPIOA
* %GPIOB
* %GPIOC
* %GPIOD
* %GPIOE
* %GPIOF
* %GPIOG
* %GPIOH
* see PRM for details on how these different busses are used.
*/
struct psb_intel_i2c_chan *psb_intel_i2c_create(struct drm_device *dev,
const u32 reg, const char *name)
{
struct psb_intel_i2c_chan *chan;
chan = kzalloc(sizeof(struct psb_intel_i2c_chan), GFP_KERNEL);
if (!chan)
goto out_free;
chan->drm_dev = dev;
chan->reg = reg;
snprintf(chan->adapter.name, I2C_NAME_SIZE, "intel drm %s", name);
chan->adapter.owner = THIS_MODULE;
chan->adapter.algo_data = &chan->algo;
chan->adapter.dev.parent = &dev->pdev->dev;
chan->algo.setsda = set_data;
chan->algo.setscl = set_clock;
chan->algo.getsda = get_data;
chan->algo.getscl = get_clock;
chan->algo.udelay = 20;
chan->algo.timeout = usecs_to_jiffies(2200);
chan->algo.data = chan;
i2c_set_adapdata(&chan->adapter, chan);
if (i2c_bit_add_bus(&chan->adapter))
goto out_free;
/* JJJ: raise SCL and SDA? */
set_data(chan, 1);
set_clock(chan, 1);
udelay(20);
return chan;
out_free:
kfree(chan);
return NULL;
}
/**
* psb_intel_i2c_destroy - unregister and free i2c bus resources
* @output: channel to free
*
* Unregister the adapter from the i2c layer, then free the structure.
*/
void psb_intel_i2c_destroy(struct psb_intel_i2c_chan *chan)
{
if (!chan)
return;
i2c_del_adapter(&chan->adapter);
kfree(chan);
}
|
