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 "drmP.h" 26 #include "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 2 34 #define ATOM_MAX_HW_I2C_READ 255 35 36 static 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; 46 47 memset(&args, 0, sizeof(args)); 48 49 base = (unsigned char *)rdev->mode_info.atom_context->scratch; 50 51 if (flags & HW_I2C_WRITE) { 52 if (num > ATOM_MAX_HW_I2C_WRITE) { 53 DRM_ERROR("hw i2c: tried to write too many bytes (%d vs 2)\n", num); 54 return -EINVAL; 55 } 56 memcpy(&out, buf, num); 57 args.lpI2CDataOut = cpu_to_le16(out); 58 } else { 59 if (num > ATOM_MAX_HW_I2C_READ) { 60 DRM_ERROR("hw i2c: tried to read too many bytes (%d vs 255)\n", num); 61 return -EINVAL; 62 } 63 } 64 65 args.ucI2CSpeed = TARGET_HW_I2C_CLOCK; 66 args.ucRegIndex = 0; 67 args.ucTransBytes = num; 68 args.ucSlaveAddr = slave_addr << 1; 69 args.ucLineNumber = chan->rec.i2c_id; 70 71 atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args); 72 73 /* error */ 74 if (args.ucStatus != HW_ASSISTED_I2C_STATUS_SUCCESS) { 75 DRM_DEBUG_KMS("hw_i2c error\n"); 76 return -EIO; 77 } 78 79 if (!(flags & HW_I2C_WRITE)) 80 memcpy(buf, base, num); 81 82 return 0; 83 } 84 85 int radeon_atom_hw_i2c_xfer(struct i2c_adapter *i2c_adap, 86 struct i2c_msg *msgs, int num) 87 { 88 struct radeon_i2c_chan *i2c = i2c_get_adapdata(i2c_adap); 89 struct i2c_msg *p; 90 int i, remaining, current_count, buffer_offset, max_bytes, ret; 91 u8 buf = 0, flags; 92 93 /* check for bus probe */ 94 p = &msgs[0]; 95 if ((num == 1) && (p->len == 0)) { 96 ret = radeon_process_i2c_ch(i2c, 97 p->addr, HW_I2C_WRITE, 98 &buf, 1); 99 if (ret) 100 return ret; 101 else 102 return num; 103 } 104 105 for (i = 0; i < num; i++) { 106 p = &msgs[i]; 107 remaining = p->len; 108 buffer_offset = 0; 109 /* max_bytes are a limitation of ProcessI2cChannelTransaction not the hw */ 110 if (p->flags & I2C_M_RD) { 111 max_bytes = ATOM_MAX_HW_I2C_READ; 112 flags = HW_I2C_READ; 113 } else { 114 max_bytes = ATOM_MAX_HW_I2C_WRITE; 115 flags = HW_I2C_WRITE; 116 } 117 while (remaining) { 118 if (remaining > max_bytes) 119 current_count = max_bytes; 120 else 121 current_count = remaining; 122 ret = radeon_process_i2c_ch(i2c, 123 p->addr, flags, 124 &p->buf[buffer_offset], current_count); 125 if (ret) 126 return ret; 127 remaining -= current_count; 128 buffer_offset += current_count; 129 } 130 } 131 132 return num; 133 } 134 135 u32 radeon_atom_hw_i2c_func(struct i2c_adapter *adap) 136 { 137 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; 138 } 139 140