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/radeon_drm.h>
27#include "radeon.h"
28#include "atom.h"
29
30#define TARGET_HW_I2C_CLOCK 50
31
32/* these are a limitation of ProcessI2cChannelTransaction not the hw */
33#define ATOM_MAX_HW_I2C_WRITE 3
34#define ATOM_MAX_HW_I2C_READ 255
35
36static int radeon_process_i2c_ch(struct radeon_i2c_chan *chan,
37 u8 slave_addr, u8 flags,
38 u8 *buf, int num)
39{
40 struct drm_device *dev = chan->dev;
41 struct radeon_device *rdev = dev->dev_private;
42 PROCESS_I2C_CHANNEL_TRANSACTION_PS_ALLOCATION args;
43 int index = GetIndexIntoMasterTable(COMMAND, ProcessI2cChannelTransaction);
44 unsigned char *base;
45 u16 out = cpu_to_le16(0);
46 int r = 0;
47
48 memset(&args, 0, sizeof(args));
49
50 mutex_lock(&chan->mutex);
51 mutex_lock(&rdev->mode_info.atom_context->scratch_mutex);
52
53 base = (unsigned char *)rdev->mode_info.atom_context->scratch;
54
55 if (flags & HW_I2C_WRITE) {
56 if (num > ATOM_MAX_HW_I2C_WRITE) {
57 DRM_ERROR("hw i2c: tried to write too many bytes (%d vs 3)\n", num);
58 r = -EINVAL;
59 goto done;
60 }
61 if (buf == NULL)
62 args.ucRegIndex = 0;
63 else
64 args.ucRegIndex = buf[0];
65 if (num)
66 num--;
67 if (num)
68 memcpy(&out, &buf[1], num);
69 args.lpI2CDataOut = cpu_to_le16(out);
70 } else {
71 if (num > ATOM_MAX_HW_I2C_READ) {
72 DRM_ERROR("hw i2c: tried to read too many bytes (%d vs 255)\n", num);
73 r = -EINVAL;
74 goto done;
75 }
76 args.ucRegIndex = 0;
77 args.lpI2CDataOut = 0;
78 }
79
80 args.ucFlag = flags;
81 args.ucI2CSpeed = TARGET_HW_I2C_CLOCK;
82 args.ucTransBytes = num;
83 args.ucSlaveAddr = slave_addr << 1;
84 args.ucLineNumber = chan->rec.i2c_id;
85
86 atom_execute_table_scratch_unlocked(rdev->mode_info.atom_context, index, (uint32_t *)&args);
87
88 /* error */
89 if (args.ucStatus != HW_ASSISTED_I2C_STATUS_SUCCESS) {
90 DRM_DEBUG_KMS("hw_i2c error\n");
91 r = -EIO;
92 goto done;
93 }
94
95 if (!(flags & HW_I2C_WRITE))
96 radeon_atom_copy_swap(buf, base, num, false);
97
98done:
99 mutex_unlock(&rdev->mode_info.atom_context->scratch_mutex);
100 mutex_unlock(&chan->mutex);
101
102 return r;
103}
104
105int radeon_atom_hw_i2c_xfer(struct i2c_adapter *i2c_adap,
106 struct i2c_msg *msgs, int num)
107{
108 struct radeon_i2c_chan *i2c = i2c_get_adapdata(i2c_adap);
109 struct i2c_msg *p;
110 int i, remaining, current_count, buffer_offset, max_bytes, ret;
111 u8 flags;
112
113 /* check for bus probe */
114 p = &msgs[0];
115 if ((num == 1) && (p->len == 0)) {
116 ret = radeon_process_i2c_ch(i2c,
117 p->addr, HW_I2C_WRITE,
118 NULL, 0);
119 if (ret)
120 return ret;
121 else
122 return num;
123 }
124
125 for (i = 0; i < num; i++) {
126 p = &msgs[i];
127 remaining = p->len;
128 buffer_offset = 0;
129 /* max_bytes are a limitation of ProcessI2cChannelTransaction not the hw */
130 if (p->flags & I2C_M_RD) {
131 max_bytes = ATOM_MAX_HW_I2C_READ;
132 flags = HW_I2C_READ;
133 } else {
134 max_bytes = ATOM_MAX_HW_I2C_WRITE;
135 flags = HW_I2C_WRITE;
136 }
137 while (remaining) {
138 if (remaining > max_bytes)
139 current_count = max_bytes;
140 else
141 current_count = remaining;
142 ret = radeon_process_i2c_ch(i2c,
143 p->addr, flags,
144 &p->buf[buffer_offset], current_count);
145 if (ret)
146 return ret;
147 remaining -= current_count;
148 buffer_offset += current_count;
149 }
150 }
151
152 return num;
153}
154
155u32 radeon_atom_hw_i2c_func(struct i2c_adapter *adap)
156{
157 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
158}
159
160