summaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/mgag200/mgag200_i2c.c
blob: 5a88ec51b5137604c0a0824fea72941e6de8ccc7 (plain)
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
/*
 * Copyright 2012 Red Hat Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 */
/*
 * Authors: Dave Airlie <airlied@redhat.com>
 */
#include <linux/export.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-bit.h>
#include <drm/drmP.h>

#include "mgag200_drv.h"

static int mga_i2c_read_gpio(struct mga_device *mdev)
{
	WREG8(DAC_INDEX, MGA1064_GEN_IO_DATA);
	return RREG8(DAC_DATA);
}

static void mga_i2c_set_gpio(struct mga_device *mdev, int mask, int val)
{
	int tmp;

	WREG8(DAC_INDEX, MGA1064_GEN_IO_CTL);
	tmp = (RREG8(DAC_DATA) & mask) | val;
	WREG_DAC(MGA1064_GEN_IO_CTL, tmp);
	WREG_DAC(MGA1064_GEN_IO_DATA, 0);
}

static inline void mga_i2c_set(struct mga_device *mdev, int mask, int state)
{
	if (state)
		state = 0;
	else
		state = mask;
	mga_i2c_set_gpio(mdev, ~mask, state);
}

static void mga_gpio_setsda(void *data, int state)
{
	struct mga_i2c_chan *i2c = data;
	struct mga_device *mdev = i2c->dev->dev_private;
	mga_i2c_set(mdev, i2c->data, state);
}

static void mga_gpio_setscl(void *data, int state)
{
	struct mga_i2c_chan *i2c = data;
	struct mga_device *mdev = i2c->dev->dev_private;
	mga_i2c_set(mdev, i2c->clock, state);
}

static int mga_gpio_getsda(void *data)
{
	struct mga_i2c_chan *i2c = data;
	struct mga_device *mdev = i2c->dev->dev_private;
	return (mga_i2c_read_gpio(mdev) & i2c->data) ? 1 : 0;
}

static int mga_gpio_getscl(void *data)
{
	struct mga_i2c_chan *i2c = data;
	struct mga_device *mdev = i2c->dev->dev_private;
	return (mga_i2c_read_gpio(mdev) & i2c->clock) ? 1 : 0;
}

struct mga_i2c_chan *mgag200_i2c_create(struct drm_device *dev)
{
	struct mga_device *mdev = dev->dev_private;
	struct mga_i2c_chan *i2c;
	int ret;
	int data, clock;

	WREG_DAC(MGA1064_GEN_IO_DATA, 0xff);
	WREG_DAC(MGA1064_GEN_IO_CTL, 0);

	switch (mdev->type) {
	case G200_SE_A:
	case G200_SE_B:
	case G200_EV:
	case G200_WB:
		data = 1;
		clock = 2;
		break;
	case G200_EH:
	case G200_ER:
		data = 2;
		clock = 1;
		break;
	default:
		data = 2;
		clock = 8;
		break;
	}

	i2c = kzalloc(sizeof(struct mga_i2c_chan), GFP_KERNEL);
	if (!i2c)
		return NULL;

	i2c->data = data;
	i2c->clock = clock;
	i2c->adapter.owner = THIS_MODULE;
	i2c->adapter.class = I2C_CLASS_DDC;
	i2c->adapter.dev.parent = &dev->pdev->dev;
	i2c->dev = dev;
	i2c_set_adapdata(&i2c->adapter, i2c);
	snprintf(i2c->adapter.name, sizeof(i2c->adapter.name), "mga i2c");

	i2c->adapter.algo_data = &i2c->bit;

	i2c->bit.udelay = 10;
	i2c->bit.timeout = 2;
	i2c->bit.data = i2c;
	i2c->bit.setsda		= mga_gpio_setsda;
	i2c->bit.setscl		= mga_gpio_setscl;
	i2c->bit.getsda		= mga_gpio_getsda;
	i2c->bit.getscl		= mga_gpio_getscl;

	ret = i2c_bit_add_bus(&i2c->adapter);
	if (ret) {
		kfree(i2c);
		i2c = NULL;
	}
	return i2c;
}

void mgag200_i2c_destroy(struct mga_i2c_chan *i2c)
{
	if (!i2c)
		return;
	i2c_del_adapter(&i2c->adapter);
	kfree(i2c);
}