1/*
2 * Copyright 2011 Advanced Micro Devices, 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 "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20 * OTHER DEALINGS IN THE SOFTWARE.
21 *
22 * Authors: Alex Deucher
23 *
24 */
25#include <drm/drmP.h>
26#include <drm/amdgpu_drm.h>
27#include "amdgpu.h"
28#include "atom.h"
29#include "amdgpu_atombios.h"
30#include "atombios_i2c.h"
31
32#define TARGET_HW_I2C_CLOCK 50
33
34/* these are a limitation of ProcessI2cChannelTransaction not the hw */
35#define ATOM_MAX_HW_I2C_WRITE 3
36#define ATOM_MAX_HW_I2C_READ 255
37
38static int amdgpu_atombios_i2c_process_i2c_ch(struct amdgpu_i2c_chan *chan,
39 u8 slave_addr, u8 flags,
40 u8 *buf, u8 num)
41{
42 struct drm_device *dev = chan->dev;
43 struct amdgpu_device *adev = dev->dev_private;
44 PROCESS_I2C_CHANNEL_TRANSACTION_PS_ALLOCATION args;
45 int index = GetIndexIntoMasterTable(COMMAND, ProcessI2cChannelTransaction);
46 unsigned char *base;
47 u16 out = cpu_to_le16(0);
48 int r = 0;
49
50 memset(&args, 0, sizeof(args));
51
52 mutex_lock(&chan->mutex);
53
54 base = (unsigned char *)adev->mode_info.atom_context->scratch;
55
56 if (flags & HW_I2C_WRITE) {
57 if (num > ATOM_MAX_HW_I2C_WRITE) {
58 DRM_ERROR("hw i2c: tried to write too many bytes (%d vs 3)\n", num);
59 r = -EINVAL;
60 goto done;
61 }
62 if (buf == NULL)
63 args.ucRegIndex = 0;
64 else
65 args.ucRegIndex = buf[0];
66 if (num)
67 num--;
68 if (num) {
69 if (buf) {
70 memcpy(&out, &buf[1], num);
71 } else {
72 DRM_ERROR("hw i2c: missing buf with num > 1\n");
73 r = -EINVAL;
74 goto done;
75 }
76 }
77 args.lpI2CDataOut = cpu_to_le16(out);
78 } else {
79 if (num > ATOM_MAX_HW_I2C_READ) {
80 DRM_ERROR("hw i2c: tried to read too many bytes (%d vs 255)\n", num);
81 r = -EINVAL;
82 goto done;
83 }
84 args.ucRegIndex = 0;
85 args.lpI2CDataOut = 0;
86 }
87
88 args.ucFlag = flags;
89 args.ucI2CSpeed = TARGET_HW_I2C_CLOCK;
90 args.ucTransBytes = num;
91 args.ucSlaveAddr = slave_addr << 1;
92 args.ucLineNumber = chan->rec.i2c_id;
93
94 amdgpu_atom_execute_table(adev->mode_info.atom_context, index, (uint32_t *)&args);
95
96 /* error */
97 if (args.ucStatus != HW_ASSISTED_I2C_STATUS_SUCCESS) {
98 DRM_DEBUG_KMS("hw_i2c error\n");
99 r = -EIO;
100 goto done;
101 }
102
103 if (!(flags & HW_I2C_WRITE))
104 amdgpu_atombios_copy_swap(buf, base, num, false);
105
106done:
107 mutex_unlock(&chan->mutex);
108
109 return r;
110}
111
112int amdgpu_atombios_i2c_xfer(struct i2c_adapter *i2c_adap,
113 struct i2c_msg *msgs, int num)
114{
115 struct amdgpu_i2c_chan *i2c = i2c_get_adapdata(i2c_adap);
116 struct i2c_msg *p;
117 int i, remaining, current_count, buffer_offset, max_bytes, ret;
118 u8 flags;
119
120 /* check for bus probe */
121 p = &msgs[0];
122 if ((num == 1) && (p->len == 0)) {
123 ret = amdgpu_atombios_i2c_process_i2c_ch(i2c,
124 p->addr, HW_I2C_WRITE,
125 NULL, 0);
126 if (ret)
127 return ret;
128 else
129 return num;
130 }
131
132 for (i = 0; i < num; i++) {
133 p = &msgs[i];
134 remaining = p->len;
135 buffer_offset = 0;
136 /* max_bytes are a limitation of ProcessI2cChannelTransaction not the hw */
137 if (p->flags & I2C_M_RD) {
138 max_bytes = ATOM_MAX_HW_I2C_READ;
139 flags = HW_I2C_READ;
140 } else {
141 max_bytes = ATOM_MAX_HW_I2C_WRITE;
142 flags = HW_I2C_WRITE;
143 }
144 while (remaining) {
145 if (remaining > max_bytes)
146 current_count = max_bytes;
147 else
148 current_count = remaining;
149 ret = amdgpu_atombios_i2c_process_i2c_ch(i2c,
150 p->addr, flags,
151 &p->buf[buffer_offset], current_count);
152 if (ret)
153 return ret;
154 remaining -= current_count;
155 buffer_offset += current_count;
156 }
157 }
158
159 return num;
160}
161
162u32 amdgpu_atombios_i2c_func(struct i2c_adapter *adap)
163{
164 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
165}
166
167void amdgpu_atombios_i2c_channel_trans(struct amdgpu_device* adev, u8 slave_addr, u8 line_number, u8 offset, u8 data)
168{
169 PROCESS_I2C_CHANNEL_TRANSACTION_PS_ALLOCATION args;
170 int index = GetIndexIntoMasterTable(COMMAND, ProcessI2cChannelTransaction);
171
172 args.ucRegIndex = offset;
173 args.lpI2CDataOut = data;
174 args.ucFlag = 1;
175 args.ucI2CSpeed = TARGET_HW_I2C_CLOCK;
176 args.ucTransBytes = 1;
177 args.ucSlaveAddr = slave_addr;
178 args.ucLineNumber = line_number;
179
180 amdgpu_atom_execute_table(adev->mode_info.atom_context, index, (uint32_t *)&args);
181}
182