tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
30extern void radeon_atom_copy_swap(u8 *dst, u8 *src, u8 num_bytes, bool to_le);
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 radeon_process_i2c_ch(struct radeon_i2c_chan *chan,
39 u8 slave_addr, u8 flags,
40 u8 *buf, u8 num)
41{
42 struct drm_device *dev = chan->dev;
43 struct radeon_device *rdev = dev->dev_private;
44 PROCESS_I2C_CHANNEL_TRANSACTION_PS_ALLOCATION args;
45 int index = GetIndexIntoMasterTable(COMMAND, ProcessI2cChannelTransaction);
46 unsigned char *base;
47 u16 out;
48
49 memset(&args, 0, sizeof(args));
50
51 base = (unsigned char *)rdev->mode_info.atom_context->scratch;
52
53 if (flags & HW_I2C_WRITE) {
54 if (num > ATOM_MAX_HW_I2C_WRITE) {
55 DRM_ERROR("hw i2c: tried to write too many bytes (%d vs 3)\n", num);
56 return -EINVAL;
57 }
58 args.ucRegIndex = buf[0];
59 if (num > 1)
60 memcpy(&out, &buf[1], num - 1);
61 args.lpI2CDataOut = cpu_to_le16(out);
62 } else {
63 if (num > ATOM_MAX_HW_I2C_READ) {
64 DRM_ERROR("hw i2c: tried to read too many bytes (%d vs 255)\n", num);
65 return -EINVAL;
66 }
67 args.ucRegIndex = 0;
68 args.lpI2CDataOut = 0;
69 }
70
71 args.ucFlag = flags;
72 args.ucI2CSpeed = TARGET_HW_I2C_CLOCK;
73 args.ucTransBytes = num;
74 args.ucSlaveAddr = slave_addr << 1;
75 args.ucLineNumber = chan->rec.i2c_id;
76
77 atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
78
79 /* error */
80 if (args.ucStatus != HW_ASSISTED_I2C_STATUS_SUCCESS) {
81 DRM_DEBUG_KMS("hw_i2c error\n");
82 return -EIO;
83 }
84
85 if (!(flags & HW_I2C_WRITE))
86 radeon_atom_copy_swap(buf, base, num, false);
87
88 return 0;
89}
90
91int radeon_atom_hw_i2c_xfer(struct i2c_adapter *i2c_adap,
92 struct i2c_msg *msgs, int num)
93{
94 struct radeon_i2c_chan *i2c = i2c_get_adapdata(i2c_adap);
95 struct i2c_msg *p;
96 int i, remaining, current_count, buffer_offset, max_bytes, ret;
97 u8 buf = 0, flags;
98
99 /* check for bus probe */
100 p = &msgs[0];
101 if ((num == 1) && (p->len == 0)) {
102 ret = radeon_process_i2c_ch(i2c,
103 p->addr, HW_I2C_WRITE,
104 &buf, 1);
105 if (ret)
106 return ret;
107 else
108 return num;
109 }
110
111 for (i = 0; i < num; i++) {
112 p = &msgs[i];
113 remaining = p->len;
114 buffer_offset = 0;
115 /* max_bytes are a limitation of ProcessI2cChannelTransaction not the hw */
116 if (p->flags & I2C_M_RD) {
117 max_bytes = ATOM_MAX_HW_I2C_READ;
118 flags = HW_I2C_READ;
119 } else {
120 max_bytes = ATOM_MAX_HW_I2C_WRITE;
121 flags = HW_I2C_WRITE;
122 }
123 while (remaining) {
124 if (remaining > max_bytes)
125 current_count = max_bytes;
126 else
127 current_count = remaining;
128 ret = radeon_process_i2c_ch(i2c,
129 p->addr, flags,
130 &p->buf[buffer_offset], current_count);
131 if (ret)
132 return ret;
133 remaining -= current_count;
134 buffer_offset += current_count;
135 }
136 }
137
138 return num;
139}
140
141u32 radeon_atom_hw_i2c_func(struct i2c_adapter *adap)
142{
143 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
144}
145