LXR linux/drivers/gpu/drm/amd/amdgpu/atombios

   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
  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 = drm_to_adev(dev);
  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                args.ucRegIndex = 0;
  80                args.lpI2CDataOut = 0;
  81        }
  82
  83        args.ucFlag = flags;
  84        args.ucI2CSpeed = TARGET_HW_I2C_CLOCK;
  85        args.ucTransBytes = num;
  86        args.ucSlaveAddr = slave_addr << 1;
  87        args.ucLineNumber = chan->rec.i2c_id;
  88
  89        amdgpu_atom_execute_table(adev->mode_info.atom_context, index, (uint32_t *)&args);
  90
  91        /* error */
  92        if (args.ucStatus != HW_ASSISTED_I2C_STATUS_SUCCESS) {
  93                DRM_DEBUG_KMS("hw_i2c error\n");
  94                r = -EIO;
  95                goto done;
  96        }
  97
  98        if (!(flags & HW_I2C_WRITE))
  99                amdgpu_atombios_copy_swap(buf, base, num, false);
 100
 101done:
 102        mutex_unlock(&chan->mutex);
 103
 104        return r;
 105}
 106
 107int amdgpu_atombios_i2c_xfer(struct i2c_adapter *i2c_adap,
 108                      struct i2c_msg *msgs, int num)
 109{
 110        struct amdgpu_i2c_chan *i2c = i2c_get_adapdata(i2c_adap);
 111        struct i2c_msg *p;
 112        int i, remaining, current_count, buffer_offset, max_bytes, ret;
 113        u8 flags;
 114
 115        /* check for bus probe */
 116        p = &msgs[0];
 117        if ((num == 1) && (p->len == 0)) {
 118                ret = amdgpu_atombios_i2c_process_i2c_ch(i2c,
 119                                                  p->addr, HW_I2C_WRITE,
 120                                                  NULL, 0);
 121                if (ret)
 122                        return ret;
 123                else
 124                        return num;
 125        }
 126
 127        for (i = 0; i < num; i++) {
 128                p = &msgs[i];
 129                remaining = p->len;
 130                buffer_offset = 0;
 131                /* max_bytes are a limitation of ProcessI2cChannelTransaction not the hw */
 132                if (p->flags & I2C_M_RD) {
 133                        max_bytes = ATOM_MAX_HW_I2C_READ;
 134                        flags = HW_I2C_READ;
 135                } else {
 136                        max_bytes = ATOM_MAX_HW_I2C_WRITE;
 137                        flags = HW_I2C_WRITE;
 138                }
 139                while (remaining) {
 140                        if (remaining > max_bytes)
 141                                current_count = max_bytes;
 142                        else
 143                                current_count = remaining;
 144                        ret = amdgpu_atombios_i2c_process_i2c_ch(i2c,
 145                                                          p->addr, flags,
 146                                                          &p->buf[buffer_offset], current_count);
 147                        if (ret)
 148                                return ret;
 149                        remaining -= current_count;
 150                        buffer_offset += current_count;
 151                }
 152        }
 153
 154        return num;
 155}
 156
 157u32 amdgpu_atombios_i2c_func(struct i2c_adapter *adap)
 158{
 159        return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 160}
 161
 162void amdgpu_atombios_i2c_channel_trans(struct amdgpu_device *adev, u8 slave_addr, u8 line_number, u8 offset, u8 data)
 163{
 164        PROCESS_I2C_CHANNEL_TRANSACTION_PS_ALLOCATION args;
 165        int index = GetIndexIntoMasterTable(COMMAND, ProcessI2cChannelTransaction);
 166
 167        args.ucRegIndex = offset;
 168        args.lpI2CDataOut = data;
 169        args.ucFlag = 1;
 170        args.ucI2CSpeed = TARGET_HW_I2C_CLOCK;
 171        args.ucTransBytes = 1;
 172        args.ucSlaveAddr = slave_addr;
 173        args.ucLineNumber = line_number;
 174
 175        amdgpu_atom_execute_table(adev->mode_info.atom_context, index, (uint32_t *)&args);
 176}
 177