1 /*
2  * Copyright 2012 Red Hat Inc.
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the
6  * "Software"), to deal in the Software without restriction, including
7  * without limitation the rights to use, copy, modify, merge, publish,
8  * distribute, sub license, and/or sell copies of the Software, and to
9  * permit persons to whom the Software is furnished to do so, subject to
10  * the following conditions:
11  *
12  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
13  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
14  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
15  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
16  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
17  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
18  * USE OR OTHER DEALINGS IN THE SOFTWARE.
19  *
20  * The above copyright notice and this permission notice (including the
21  * next paragraph) shall be included in all copies or substantial portions
22  * of the Software.
23  *
24  */
25 /*
26  * Authors: Dave Airlie <airlied@redhat.com>
27  */
28 
29 #include <linux/export.h>
30 #include <linux/i2c-algo-bit.h>
31 #include <linux/i2c.h>
32 
33 #include <drm/drm_pci.h>
34 
35 #include "mgag200_drv.h"
36 
37 static int mga_i2c_read_gpio(struct mga_device *mdev)
38 {
39 	WREG8(DAC_INDEX, MGA1064_GEN_IO_DATA);
40 	return RREG8(DAC_DATA);
41 }
42 
43 static void mga_i2c_set_gpio(struct mga_device *mdev, int mask, int val)
44 {
45 	int tmp;
46 
47 	WREG8(DAC_INDEX, MGA1064_GEN_IO_CTL);
48 	tmp = (RREG8(DAC_DATA) & mask) | val;
49 	WREG_DAC(MGA1064_GEN_IO_CTL, tmp);
50 	WREG_DAC(MGA1064_GEN_IO_DATA, 0);
51 }
52 
53 static inline void mga_i2c_set(struct mga_device *mdev, int mask, int state)
54 {
55 	if (state)
56 		state = 0;
57 	else
58 		state = mask;
59 	mga_i2c_set_gpio(mdev, ~mask, state);
60 }
61 
62 static void mga_gpio_setsda(void *data, int state)
63 {
64 	struct mga_i2c_chan *i2c = data;
65 	struct mga_device *mdev = i2c->dev->dev_private;
66 	mga_i2c_set(mdev, i2c->data, state);
67 }
68 
69 static void mga_gpio_setscl(void *data, int state)
70 {
71 	struct mga_i2c_chan *i2c = data;
72 	struct mga_device *mdev = i2c->dev->dev_private;
73 	mga_i2c_set(mdev, i2c->clock, state);
74 }
75 
76 static int mga_gpio_getsda(void *data)
77 {
78 	struct mga_i2c_chan *i2c = data;
79 	struct mga_device *mdev = i2c->dev->dev_private;
80 	return (mga_i2c_read_gpio(mdev) & i2c->data) ? 1 : 0;
81 }
82 
83 static int mga_gpio_getscl(void *data)
84 {
85 	struct mga_i2c_chan *i2c = data;
86 	struct mga_device *mdev = i2c->dev->dev_private;
87 	return (mga_i2c_read_gpio(mdev) & i2c->clock) ? 1 : 0;
88 }
89 
90 struct mga_i2c_chan *mgag200_i2c_create(struct drm_device *dev)
91 {
92 	struct mga_device *mdev = dev->dev_private;
93 	struct mga_i2c_chan *i2c;
94 	int ret;
95 	int data, clock;
96 
97 	WREG_DAC(MGA1064_GEN_IO_CTL2, 1);
98 	WREG_DAC(MGA1064_GEN_IO_DATA, 0xff);
99 	WREG_DAC(MGA1064_GEN_IO_CTL, 0);
100 
101 	switch (mdev->type) {
102 	case G200_SE_A:
103 	case G200_SE_B:
104 	case G200_EV:
105 	case G200_WB:
106 	case G200_EW3:
107 		data = 1;
108 		clock = 2;
109 		break;
110 	case G200_EH:
111 	case G200_EH3:
112 	case G200_ER:
113 		data = 2;
114 		clock = 1;
115 		break;
116 	default:
117 		data = 2;
118 		clock = 8;
119 		break;
120 	}
121 
122 	i2c = kzalloc(sizeof(struct mga_i2c_chan), GFP_KERNEL);
123 	if (!i2c)
124 		return NULL;
125 
126 	i2c->data = data;
127 	i2c->clock = clock;
128 	i2c->adapter.owner = THIS_MODULE;
129 	i2c->adapter.class = I2C_CLASS_DDC;
130 	i2c->adapter.dev.parent = &dev->pdev->dev;
131 	i2c->dev = dev;
132 	i2c_set_adapdata(&i2c->adapter, i2c);
133 	snprintf(i2c->adapter.name, sizeof(i2c->adapter.name), "mga i2c");
134 
135 	i2c->adapter.algo_data = &i2c->bit;
136 
137 	i2c->bit.udelay = 10;
138 	i2c->bit.timeout = 2;
139 	i2c->bit.data = i2c;
140 	i2c->bit.setsda		= mga_gpio_setsda;
141 	i2c->bit.setscl		= mga_gpio_setscl;
142 	i2c->bit.getsda		= mga_gpio_getsda;
143 	i2c->bit.getscl		= mga_gpio_getscl;
144 
145 	ret = i2c_bit_add_bus(&i2c->adapter);
146 	if (ret) {
147 		kfree(i2c);
148 		i2c = NULL;
149 	}
150 	return i2c;
151 }
152 
153 void mgag200_i2c_destroy(struct mga_i2c_chan *i2c)
154 {
155 	if (!i2c)
156 		return;
157 	i2c_del_adapter(&i2c->adapter);
158 	kfree(i2c);
159 }
160 
161