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/i2c-algo-bit.h>
30 #include <linux/i2c.h>
31 #include <linux/pci.h>
32
33 #include <drm/drm_managed.h>
34
35 #include "mgag200_ddc.h"
36 #include "mgag200_drv.h"
37
38 struct mgag200_ddc {
39 struct mga_device *mdev;
40
41 int data;
42 int clock;
43
44 struct i2c_algo_bit_data bit;
45 struct i2c_adapter adapter;
46 };
47
mga_i2c_read_gpio(struct mga_device * mdev)48 static int mga_i2c_read_gpio(struct mga_device *mdev)
49 {
50 WREG8(DAC_INDEX, MGA1064_GEN_IO_DATA);
51 return RREG8(DAC_DATA);
52 }
53
mga_i2c_set_gpio(struct mga_device * mdev,int mask,int val)54 static void mga_i2c_set_gpio(struct mga_device *mdev, int mask, int val)
55 {
56 int tmp;
57
58 WREG8(DAC_INDEX, MGA1064_GEN_IO_CTL);
59 tmp = (RREG8(DAC_DATA) & mask) | val;
60 WREG_DAC(MGA1064_GEN_IO_CTL, tmp);
61 WREG_DAC(MGA1064_GEN_IO_DATA, 0);
62 }
63
mga_i2c_set(struct mga_device * mdev,int mask,int state)64 static inline void mga_i2c_set(struct mga_device *mdev, int mask, int state)
65 {
66 if (state)
67 state = 0;
68 else
69 state = mask;
70 mga_i2c_set_gpio(mdev, ~mask, state);
71 }
72
mgag200_ddc_algo_bit_data_setsda(void * data,int state)73 static void mgag200_ddc_algo_bit_data_setsda(void *data, int state)
74 {
75 struct mgag200_ddc *ddc = data;
76
77 mga_i2c_set(ddc->mdev, ddc->data, state);
78 }
79
mgag200_ddc_algo_bit_data_setscl(void * data,int state)80 static void mgag200_ddc_algo_bit_data_setscl(void *data, int state)
81 {
82 struct mgag200_ddc *ddc = data;
83
84 mga_i2c_set(ddc->mdev, ddc->clock, state);
85 }
86
mgag200_ddc_algo_bit_data_getsda(void * data)87 static int mgag200_ddc_algo_bit_data_getsda(void *data)
88 {
89 struct mgag200_ddc *ddc = data;
90
91 return (mga_i2c_read_gpio(ddc->mdev) & ddc->data) ? 1 : 0;
92 }
93
mgag200_ddc_algo_bit_data_getscl(void * data)94 static int mgag200_ddc_algo_bit_data_getscl(void *data)
95 {
96 struct mgag200_ddc *ddc = data;
97
98 return (mga_i2c_read_gpio(ddc->mdev) & ddc->clock) ? 1 : 0;
99 }
100
mgag200_ddc_algo_bit_data_pre_xfer(struct i2c_adapter * adapter)101 static int mgag200_ddc_algo_bit_data_pre_xfer(struct i2c_adapter *adapter)
102 {
103 struct mgag200_ddc *ddc = i2c_get_adapdata(adapter);
104 struct mga_device *mdev = ddc->mdev;
105
106 /*
107 * Protect access to I/O registers from concurrent modesetting
108 * by acquiring the I/O-register lock.
109 */
110 mutex_lock(&mdev->rmmio_lock);
111
112 return 0;
113 }
114
mgag200_ddc_algo_bit_data_post_xfer(struct i2c_adapter * adapter)115 static void mgag200_ddc_algo_bit_data_post_xfer(struct i2c_adapter *adapter)
116 {
117 struct mgag200_ddc *ddc = i2c_get_adapdata(adapter);
118 struct mga_device *mdev = ddc->mdev;
119
120 mutex_unlock(&mdev->rmmio_lock);
121 }
122
mgag200_ddc_release(struct drm_device * dev,void * res)123 static void mgag200_ddc_release(struct drm_device *dev, void *res)
124 {
125 struct mgag200_ddc *ddc = res;
126
127 i2c_del_adapter(&ddc->adapter);
128 }
129
mgag200_ddc_create(struct mga_device * mdev)130 struct i2c_adapter *mgag200_ddc_create(struct mga_device *mdev)
131 {
132 struct drm_device *dev = &mdev->base;
133 const struct mgag200_device_info *info = mdev->info;
134 struct mgag200_ddc *ddc;
135 struct i2c_algo_bit_data *bit;
136 struct i2c_adapter *adapter;
137 int ret;
138
139 ddc = drmm_kzalloc(dev, sizeof(*ddc), GFP_KERNEL);
140 if (!ddc)
141 return ERR_PTR(-ENOMEM);
142
143 WREG_DAC(MGA1064_GEN_IO_CTL2, 1);
144 WREG_DAC(MGA1064_GEN_IO_DATA, 0xff);
145 WREG_DAC(MGA1064_GEN_IO_CTL, 0);
146
147 ddc->mdev = mdev;
148 ddc->data = BIT(info->i2c.data_bit);
149 ddc->clock = BIT(info->i2c.clock_bit);
150
151 bit = &ddc->bit;
152 bit->data = ddc;
153 bit->setsda = mgag200_ddc_algo_bit_data_setsda;
154 bit->setscl = mgag200_ddc_algo_bit_data_setscl;
155 bit->getsda = mgag200_ddc_algo_bit_data_getsda;
156 bit->getscl = mgag200_ddc_algo_bit_data_getscl;
157 bit->pre_xfer = mgag200_ddc_algo_bit_data_pre_xfer;
158 bit->post_xfer = mgag200_ddc_algo_bit_data_post_xfer;
159 bit->udelay = 10;
160 bit->timeout = usecs_to_jiffies(2200);
161
162 adapter = &ddc->adapter;
163 adapter->owner = THIS_MODULE;
164 adapter->algo_data = bit;
165 adapter->dev.parent = dev->dev;
166 snprintf(adapter->name, sizeof(adapter->name), "Matrox DDC bus");
167 i2c_set_adapdata(adapter, ddc);
168
169 ret = i2c_bit_add_bus(adapter);
170 if (ret)
171 return ERR_PTR(ret);
172
173 ret = drmm_add_action_or_reset(dev, mgag200_ddc_release, ddc);
174 if (ret)
175 return ERR_PTR(ret);
176
177 return adapter;
178 }
179