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 #include <linux/pci.h>
33
34 #include <drm/drm_managed.h>
35
36 #include "mgag200_ddc.h"
37 #include "mgag200_drv.h"
38
39 struct mgag200_ddc {
40 struct mga_device *mdev;
41
42 int data;
43 int clock;
44
45 struct i2c_algo_bit_data bit;
46 struct i2c_adapter adapter;
47 };
48
mga_i2c_read_gpio(struct mga_device * mdev)49 static int mga_i2c_read_gpio(struct mga_device *mdev)
50 {
51 WREG8(DAC_INDEX, MGA1064_GEN_IO_DATA);
52 return RREG8(DAC_DATA);
53 }
54
mga_i2c_set_gpio(struct mga_device * mdev,int mask,int val)55 static void mga_i2c_set_gpio(struct mga_device *mdev, int mask, int val)
56 {
57 int tmp;
58
59 WREG8(DAC_INDEX, MGA1064_GEN_IO_CTL);
60 tmp = (RREG8(DAC_DATA) & mask) | val;
61 WREG_DAC(MGA1064_GEN_IO_CTL, tmp);
62 WREG_DAC(MGA1064_GEN_IO_DATA, 0);
63 }
64
mga_i2c_set(struct mga_device * mdev,int mask,int state)65 static inline void mga_i2c_set(struct mga_device *mdev, int mask, int state)
66 {
67 if (state)
68 state = 0;
69 else
70 state = mask;
71 mga_i2c_set_gpio(mdev, ~mask, state);
72 }
73
mgag200_ddc_algo_bit_data_setsda(void * data,int state)74 static void mgag200_ddc_algo_bit_data_setsda(void *data, int state)
75 {
76 struct mgag200_ddc *ddc = data;
77
78 mga_i2c_set(ddc->mdev, ddc->data, state);
79 }
80
mgag200_ddc_algo_bit_data_setscl(void * data,int state)81 static void mgag200_ddc_algo_bit_data_setscl(void *data, int state)
82 {
83 struct mgag200_ddc *ddc = data;
84
85 mga_i2c_set(ddc->mdev, ddc->clock, state);
86 }
87
mgag200_ddc_algo_bit_data_getsda(void * data)88 static int mgag200_ddc_algo_bit_data_getsda(void *data)
89 {
90 struct mgag200_ddc *ddc = data;
91
92 return (mga_i2c_read_gpio(ddc->mdev) & ddc->data) ? 1 : 0;
93 }
94
mgag200_ddc_algo_bit_data_getscl(void * data)95 static int mgag200_ddc_algo_bit_data_getscl(void *data)
96 {
97 struct mgag200_ddc *ddc = data;
98
99 return (mga_i2c_read_gpio(ddc->mdev) & ddc->clock) ? 1 : 0;
100 }
101
mgag200_ddc_algo_bit_data_pre_xfer(struct i2c_adapter * adapter)102 static int mgag200_ddc_algo_bit_data_pre_xfer(struct i2c_adapter *adapter)
103 {
104 struct mgag200_ddc *ddc = i2c_get_adapdata(adapter);
105 struct mga_device *mdev = ddc->mdev;
106
107 /*
108 * Protect access to I/O registers from concurrent modesetting
109 * by acquiring the I/O-register lock.
110 */
111 mutex_lock(&mdev->rmmio_lock);
112
113 return 0;
114 }
115
mgag200_ddc_algo_bit_data_post_xfer(struct i2c_adapter * adapter)116 static void mgag200_ddc_algo_bit_data_post_xfer(struct i2c_adapter *adapter)
117 {
118 struct mgag200_ddc *ddc = i2c_get_adapdata(adapter);
119 struct mga_device *mdev = ddc->mdev;
120
121 mutex_unlock(&mdev->rmmio_lock);
122 }
123
mgag200_ddc_release(struct drm_device * dev,void * res)124 static void mgag200_ddc_release(struct drm_device *dev, void *res)
125 {
126 struct mgag200_ddc *ddc = res;
127
128 i2c_del_adapter(&ddc->adapter);
129 }
130
mgag200_ddc_create(struct mga_device * mdev)131 struct i2c_adapter *mgag200_ddc_create(struct mga_device *mdev)
132 {
133 struct drm_device *dev = &mdev->base;
134 const struct mgag200_device_info *info = mdev->info;
135 struct mgag200_ddc *ddc;
136 struct i2c_algo_bit_data *bit;
137 struct i2c_adapter *adapter;
138 int ret;
139
140 ddc = drmm_kzalloc(dev, sizeof(*ddc), GFP_KERNEL);
141 if (!ddc)
142 return ERR_PTR(-ENOMEM);
143
144 WREG_DAC(MGA1064_GEN_IO_CTL2, 1);
145 WREG_DAC(MGA1064_GEN_IO_DATA, 0xff);
146 WREG_DAC(MGA1064_GEN_IO_CTL, 0);
147
148 ddc->mdev = mdev;
149 ddc->data = BIT(info->i2c.data_bit);
150 ddc->clock = BIT(info->i2c.clock_bit);
151
152 bit = &ddc->bit;
153 bit->data = ddc;
154 bit->setsda = mgag200_ddc_algo_bit_data_setsda;
155 bit->setscl = mgag200_ddc_algo_bit_data_setscl;
156 bit->getsda = mgag200_ddc_algo_bit_data_getsda;
157 bit->getscl = mgag200_ddc_algo_bit_data_getscl;
158 bit->pre_xfer = mgag200_ddc_algo_bit_data_pre_xfer;
159 bit->post_xfer = mgag200_ddc_algo_bit_data_post_xfer;
160 bit->udelay = 10;
161 bit->timeout = usecs_to_jiffies(2200);
162
163 adapter = &ddc->adapter;
164 adapter->owner = THIS_MODULE;
165 adapter->algo_data = bit;
166 adapter->dev.parent = dev->dev;
167 snprintf(adapter->name, sizeof(adapter->name), "Matrox DDC bus");
168 i2c_set_adapdata(adapter, ddc);
169
170 ret = i2c_bit_add_bus(adapter);
171 if (ret)
172 return ERR_PTR(ret);
173
174 ret = drmm_add_action_or_reset(dev, mgag200_ddc_release, ddc);
175 if (ret)
176 return ERR_PTR(ret);
177
178 return adapter;
179 }
180