amd/amdgpu/atombios_i2c.c

0001 /*
0002  * Copyright 2011 Advanced Micro Devices, Inc.
0003  *
0004  * Permission is hereby granted, free of charge, to any person obtaining a
0005  * copy of this software and associated documentation files (the "Software"),
0006  * to deal in the Software without restriction, including without limitation
0007  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
0008  * and/or sell copies of the Software, and to permit persons to whom the
0009  * Software is furnished to do so, subject to the following conditions:
0010  *
0011  * The above copyright notice and this permission notice shall be included in
0012  * all copies or substantial portions of the Software.
0013  *
0014  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
0015  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
0016  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
0017  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
0018  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
0019  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
0020  * OTHER DEALINGS IN THE SOFTWARE.
0021  *
0022  * Authors: Alex Deucher
0023  *
0024  */
0025
0026 #include <drm/amdgpu_drm.h>
0027 #include "amdgpu.h"
0028 #include "atom.h"
0029 #include "amdgpu_atombios.h"
0030 #include "atombios_i2c.h"
0031
0032 #define TARGET_HW_I2C_CLOCK 50
0033
0034 /* these are a limitation of ProcessI2cChannelTransaction not the hw */
0035 #define ATOM_MAX_HW_I2C_WRITE 3
0036 #define ATOM_MAX_HW_I2C_READ  255
0037
0038 static int amdgpu_atombios_i2c_process_i2c_ch(struct amdgpu_i2c_chan *chan,
0039                        u8 slave_addr, u8 flags,
0040                        u8 *buf, u8 num)
0041 {
0042     struct drm_device *dev = chan->dev;
0043     struct amdgpu_device *adev = drm_to_adev(dev);
0044     PROCESS_I2C_CHANNEL_TRANSACTION_PS_ALLOCATION args;
0045     int index = GetIndexIntoMasterTable(COMMAND, ProcessI2cChannelTransaction);
0046     unsigned char *base;
0047     u16 out = cpu_to_le16(0);
0048     int r = 0;
0049
0050     memset(&args, 0, sizeof(args));
0051
0052     mutex_lock(&chan->mutex);
0053
0054     base = (unsigned char *)adev->mode_info.atom_context->scratch;
0055
0056     if (flags & HW_I2C_WRITE) {
0057         if (num > ATOM_MAX_HW_I2C_WRITE) {
0058             DRM_ERROR("hw i2c: tried to write too many bytes (%d vs 3)\n", num);
0059             r = -EINVAL;
0060             goto done;
0061         }
0062         if (buf == NULL)
0063             args.ucRegIndex = 0;
0064         else
0065             args.ucRegIndex = buf[0];
0066         if (num)
0067             num--;
0068         if (num) {
0069             if (buf) {
0070                 memcpy(&out, &buf[1], num);
0071             } else {
0072                 DRM_ERROR("hw i2c: missing buf with num > 1\n");
0073                 r = -EINVAL;
0074                 goto done;
0075             }
0076         }
0077         args.lpI2CDataOut = cpu_to_le16(out);
0078     } else {
0079         args.ucRegIndex = 0;
0080         args.lpI2CDataOut = 0;
0081     }
0082
0083     args.ucFlag = flags;
0084     args.ucI2CSpeed = TARGET_HW_I2C_CLOCK;
0085     args.ucTransBytes = num;
0086     args.ucSlaveAddr = slave_addr << 1;
0087     args.ucLineNumber = chan->rec.i2c_id;
0088
0089     amdgpu_atom_execute_table(adev->mode_info.atom_context, index, (uint32_t *)&args);
0090
0091     /* error */
0092     if (args.ucStatus != HW_ASSISTED_I2C_STATUS_SUCCESS) {
0093         DRM_DEBUG_KMS("hw_i2c error\n");
0094         r = -EIO;
0095         goto done;
0096     }
0097
0098     if (!(flags & HW_I2C_WRITE))
0099         amdgpu_atombios_copy_swap(buf, base, num, false);
0100
0101 done:
0102     mutex_unlock(&chan->mutex);
0103
0104     return r;
0105 }
0106
0107 int amdgpu_atombios_i2c_xfer(struct i2c_adapter *i2c_adap,
0108               struct i2c_msg *msgs, int num)
0109 {
0110     struct amdgpu_i2c_chan *i2c = i2c_get_adapdata(i2c_adap);
0111     struct i2c_msg *p;
0112     int i, remaining, current_count, buffer_offset, max_bytes, ret;
0113     u8 flags;
0114
0115     /* check for bus probe */
0116     p = &msgs[0];
0117     if ((num == 1) && (p->len == 0)) {
0118         ret = amdgpu_atombios_i2c_process_i2c_ch(i2c,
0119                           p->addr, HW_I2C_WRITE,
0120                           NULL, 0);
0121         if (ret)
0122             return ret;
0123         else
0124             return num;
0125     }
0126
0127     for (i = 0; i < num; i++) {
0128         p = &msgs[i];
0129         remaining = p->len;
0130         buffer_offset = 0;
0131         /* max_bytes are a limitation of ProcessI2cChannelTransaction not the hw */
0132         if (p->flags & I2C_M_RD) {
0133             max_bytes = ATOM_MAX_HW_I2C_READ;
0134             flags = HW_I2C_READ;
0135         } else {
0136             max_bytes = ATOM_MAX_HW_I2C_WRITE;
0137             flags = HW_I2C_WRITE;
0138         }
0139         while (remaining) {
0140             if (remaining > max_bytes)
0141                 current_count = max_bytes;
0142             else
0143                 current_count = remaining;
0144             ret = amdgpu_atombios_i2c_process_i2c_ch(i2c,
0145                               p->addr, flags,
0146                               &p->buf[buffer_offset], current_count);
0147             if (ret)
0148                 return ret;
0149             remaining -= current_count;
0150             buffer_offset += current_count;
0151         }
0152     }
0153
0154     return num;
0155 }
0156
0157 u32 amdgpu_atombios_i2c_func(struct i2c_adapter *adap)
0158 {
0159     return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
0160 }
0161
0162 void amdgpu_atombios_i2c_channel_trans(struct amdgpu_device *adev, u8 slave_addr, u8 line_number, u8 offset, u8 data)
0163 {
0164     PROCESS_I2C_CHANNEL_TRANSACTION_PS_ALLOCATION args;
0165     int index = GetIndexIntoMasterTable(COMMAND, ProcessI2cChannelTransaction);
0166
0167     args.ucRegIndex = offset;
0168     args.lpI2CDataOut = data;
0169     args.ucFlag = 1;
0170     args.ucI2CSpeed = TARGET_HW_I2C_CLOCK;
0171     args.ucTransBytes = 1;
0172     args.ucSlaveAddr = slave_addr;
0173     args.ucLineNumber = line_number;
0174
0175     amdgpu_atom_execute_table(adev->mode_info.atom_context, index, (uint32_t *)&args);
0176 }