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#include <linux/export.h>
29#include <linux/i2c.h>
30#include <linux/i2c-algo-bit.h>
31#include <drm/drmP.h>
32
33#include "mgag200_drv.h"
34
35static int mga_i2c_read_gpio(struct mga_device *mdev)
36{
37	WREG8(DAC_INDEX, MGA1064_GEN_IO_DATA);
38	return RREG8(DAC_DATA);
39}
40
41static void mga_i2c_set_gpio(struct mga_device *mdev, int mask, int val)
42{
43	int tmp;
44
45	WREG8(DAC_INDEX, MGA1064_GEN_IO_CTL);
46	tmp = (RREG8(DAC_DATA) & mask) | val;
47	WREG_DAC(MGA1064_GEN_IO_CTL, tmp);
48	WREG_DAC(MGA1064_GEN_IO_DATA, 0);
49}
50
51static inline void mga_i2c_set(struct mga_device *mdev, int mask, int state)
52{
53	if (state)
54		state = 0;
55	else
56		state = mask;
57	mga_i2c_set_gpio(mdev, ~mask, state);
58}
59
60static void mga_gpio_setsda(void *data, int state)
61{
62	struct mga_i2c_chan *i2c = data;
63	struct mga_device *mdev = i2c->dev->dev_private;
64	mga_i2c_set(mdev, i2c->data, state);
65}
66
67static void mga_gpio_setscl(void *data, int state)
68{
69	struct mga_i2c_chan *i2c = data;
70	struct mga_device *mdev = i2c->dev->dev_private;
71	mga_i2c_set(mdev, i2c->clock, state);
72}
73
74static int mga_gpio_getsda(void *data)
75{
76	struct mga_i2c_chan *i2c = data;
77	struct mga_device *mdev = i2c->dev->dev_private;
78	return (mga_i2c_read_gpio(mdev) & i2c->data) ? 1 : 0;
79}
80
81static int mga_gpio_getscl(void *data)
82{
83	struct mga_i2c_chan *i2c = data;
84	struct mga_device *mdev = i2c->dev->dev_private;
85	return (mga_i2c_read_gpio(mdev) & i2c->clock) ? 1 : 0;
86}
87
88struct mga_i2c_chan *mgag200_i2c_create(struct drm_device *dev)
89{
90	struct mga_device *mdev = dev->dev_private;
91	struct mga_i2c_chan *i2c;
92	int ret;
93	int data, clock;
94
95	WREG_DAC(MGA1064_GEN_IO_CTL2, 1);
96	WREG_DAC(MGA1064_GEN_IO_DATA, 0xff);
97	WREG_DAC(MGA1064_GEN_IO_CTL, 0);
98
99	switch (mdev->type) {
100	case G200_SE_A:
101	case G200_SE_B:
102	case G200_EV:
103	case G200_WB:
104	case G200_EW3:
105		data = 1;
106		clock = 2;
107		break;
108	case G200_EH:
109	case G200_ER:
110		data = 2;
111		clock = 1;
112		break;
113	default:
114		data = 2;
115		clock = 8;
116		break;
117	}
118
119	i2c = kzalloc(sizeof(struct mga_i2c_chan), GFP_KERNEL);
120	if (!i2c)
121		return NULL;
122
123	i2c->data = data;
124	i2c->clock = clock;
125	i2c->adapter.owner = THIS_MODULE;
126	i2c->adapter.class = I2C_CLASS_DDC;
127	i2c->adapter.dev.parent = &dev->pdev->dev;
128	i2c->dev = dev;
129	i2c_set_adapdata(&i2c->adapter, i2c);
130	snprintf(i2c->adapter.name, sizeof(i2c->adapter.name), "mga i2c");
131
132	i2c->adapter.algo_data = &i2c->bit;
133
134	i2c->bit.udelay = 10;
135	i2c->bit.timeout = 2;
136	i2c->bit.data = i2c;
137	i2c->bit.setsda		= mga_gpio_setsda;
138	i2c->bit.setscl		= mga_gpio_setscl;
139	i2c->bit.getsda		= mga_gpio_getsda;
140	i2c->bit.getscl		= mga_gpio_getscl;
141
142	ret = i2c_bit_add_bus(&i2c->adapter);
143	if (ret) {
144		kfree(i2c);
145		i2c = NULL;
146	}
147	return i2c;
148}
149
150void mgag200_i2c_destroy(struct mga_i2c_chan *i2c)
151{
152	if (!i2c)
153		return;
154	i2c_del_adapter(&i2c->adapter);
155	kfree(i2c);
156}
157
158