LXR linux/drivers/gpu/drm/radeon/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#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, u8 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