sys/dev/drm/radeon/atombios_i2c.c

   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  * $FreeBSD: head/sys/dev/drm2/radeon/atombios_i2c.c 254885 2013-08-25 19:37:15Z dumbbell $
  25  */
  26
  27 #include <drm/drmP.h>
  28 #include <uapi_drm/radeon_drm.h>
  29 #include <bus/iicbus/iic.h>
  30 #include <bus/iicbus/iiconf.h>
  31 #include <bus/iicbus/iicbus.h>
  32 #include "radeon.h"
  33 #include "atom.h"
  34 #include "iicbus_if.h"
  35 #include "iicbb_if.h"
  36
  37 #define TARGET_HW_I2C_CLOCK 50
  38
  39 /* these are a limitation of ProcessI2cChannelTransaction not the hw */
  40 #define ATOM_MAX_HW_I2C_WRITE 3
  41 #define ATOM_MAX_HW_I2C_READ  255
  42
  43 static int radeon_process_i2c_ch(struct radeon_i2c_chan *chan,
  44                                  u8 slave_addr, u8 flags,
  45                                  u8 *buf, u8 num)
  46 {
  47         struct drm_device *dev = chan->dev;
  48         struct radeon_device *rdev = dev->dev_private;
  49         PROCESS_I2C_CHANNEL_TRANSACTION_PS_ALLOCATION args;
  50         int index = GetIndexIntoMasterTable(COMMAND, ProcessI2cChannelTransaction);
  51         unsigned char *base;
  52         u16 out = cpu_to_le16(0);
  53         int r = 0;
  54
  55         memset(&args, 0, sizeof(args));
  56
  57         lockmgr(&chan->mutex, LK_EXCLUSIVE);
  58         lockmgr(&rdev->mode_info.atom_context->scratch_mutex, LK_EXCLUSIVE);
  59
  60         base = (unsigned char *)rdev->mode_info.atom_context->scratch;
  61
  62         if (flags & HW_I2C_WRITE) {
  63                 if (num > ATOM_MAX_HW_I2C_WRITE) {
  64                         DRM_ERROR("hw i2c: tried to write too many bytes (%d vs 3)\n", num);
  65                         r = -EINVAL;
  66                         goto done;
  67                 }
  68                 if (buf == NULL)
  69                         args.ucRegIndex = 0;
  70                 else
  71                         args.ucRegIndex = buf[0];
  72                 if (num)
  73                         num--;
  74                 if (num)
  75                         memcpy(&out, &buf[1], num);
  76                 args.lpI2CDataOut = cpu_to_le16(out);
  77         } else {
  78                 if (num > ATOM_MAX_HW_I2C_READ) {
  79                         DRM_ERROR("hw i2c: tried to read too many bytes (%d vs 255)\n", num);
  80                         r = -EINVAL;
  81                         goto done;
  82                 }
  83                 args.ucRegIndex = 0;
  84                 args.lpI2CDataOut = 0;
  85         }
  86
  87         args.ucFlag = flags;
  88         args.ucI2CSpeed = TARGET_HW_I2C_CLOCK;
  89         args.ucTransBytes = num;
  90         args.ucSlaveAddr = slave_addr << 1;
  91         args.ucLineNumber = chan->rec.i2c_id;
  92
  93         atom_execute_table_scratch_unlocked(rdev->mode_info.atom_context, index, (uint32_t *)&args);
  94
  95         /* error */
  96         if (args.ucStatus != HW_ASSISTED_I2C_STATUS_SUCCESS) {
  97                 DRM_DEBUG_KMS("hw_i2c error\n");
  98                 r = -EIO;
  99                 goto done;
 100         }
 101
 102         if (!(flags & HW_I2C_WRITE))
 103                 radeon_atom_copy_swap(buf, base, num, false);
 104
 105 done:
 106         lockmgr(&rdev->mode_info.atom_context->scratch_mutex, LK_RELEASE);
 107         lockmgr(&chan->mutex, LK_RELEASE);
 108
 109         return r;
 110 }
 111
 112 static int
 113 radeon_atom_hw_i2c_xfer(device_t dev, struct iic_msg *msgs, u_int num)
 114 {
 115         struct radeon_i2c_chan *i2c = device_get_softc(dev);
 116         struct iic_msg *p;
 117         int i, remaining, current_count, buffer_offset, max_bytes, ret;
 118         u8 flags;
 119
 120         /* check for bus probe */
 121         p = &msgs[0];
 122         if ((num == 1) && (p->len == 0)) {
 123                 ret = radeon_process_i2c_ch(i2c,
 124                                             p->slave, HW_I2C_WRITE,
 125                                             NULL, 0);
 126                 if (ret)
 127                         return ret;
 128                 else
 129                         return (0);
 130         }
 131
 132         for (i = 0; i < num; i++) {
 133                 p = &msgs[i];
 134                 remaining = p->len;
 135                 buffer_offset = 0;
 136                 /* max_bytes are a limitation of ProcessI2cChannelTransaction not the hw */
 137                 if (p->flags & IIC_M_RD) {
 138                         max_bytes = ATOM_MAX_HW_I2C_READ;
 139                         flags = HW_I2C_READ;
 140                 } else {
 141                         max_bytes = ATOM_MAX_HW_I2C_WRITE;
 142                         flags = HW_I2C_WRITE;
 143                 }
 144                 while (remaining) {
 145                         if (remaining > max_bytes)
 146                                 current_count = max_bytes;
 147                         else
 148                                 current_count = remaining;
 149                         ret = radeon_process_i2c_ch(i2c,
 150                                                     p->slave, flags,
 151                                                     &p->buf[buffer_offset], current_count);
 152                         if (ret)
 153                                 return ret;
 154                         remaining -= current_count;
 155                         buffer_offset += current_count;
 156                 }
 157         }
 158
 159         return (0);
 160 }
 161
 162 static int
 163 radeon_atom_hw_i2c_probe(device_t dev)
 164 {
 165
 166         return (BUS_PROBE_SPECIFIC);
 167 }
 168
 169 static int
 170 radeon_atom_hw_i2c_attach(device_t dev)
 171 {
 172         struct radeon_i2c_chan *i2c;
 173         device_t iic_dev;
 174
 175         i2c = device_get_softc(dev);
 176         device_set_desc(dev, i2c->name);
 177
 178         /* add generic bit-banging code */
 179         iic_dev = device_add_child(dev, "iicbus", -1);
 180         if (iic_dev == NULL)
 181                 return (ENXIO);
 182         device_quiet(iic_dev);
 183
 184         /* attach and probe added child */
 185         bus_generic_attach(dev);
 186
 187         return (0);
 188 }
 189
 190 static int
 191 radeon_atom_hw_i2c_detach(device_t dev)
 192 {
 193         /* detach bit-banding code. */
 194         bus_generic_detach(dev);
 195
 196         /* delete bit-banding code. */
 197         device_delete_children(dev);
 198         return (0);
 199 }
 200
 201 static int
 202 radeon_atom_hw_i2c_reset(device_t dev, u_char speed,
 203     u_char addr, u_char *oldaddr)
 204 {
 205
 206         return (0);
 207 }
 208
 209 static device_method_t radeon_atom_hw_i2c_methods[] = {
 210         DEVMETHOD(device_probe,         radeon_atom_hw_i2c_probe),
 211         DEVMETHOD(device_attach,        radeon_atom_hw_i2c_attach),
 212         DEVMETHOD(device_detach,        radeon_atom_hw_i2c_detach),
 213         DEVMETHOD(iicbus_reset,         radeon_atom_hw_i2c_reset),
 214         DEVMETHOD(iicbus_transfer,      radeon_atom_hw_i2c_xfer),
 215         DEVMETHOD_END
 216 };
 217
 218 static driver_t radeon_atom_hw_i2c_driver = {
 219         "radeon_atom_hw_i2c",
 220         radeon_atom_hw_i2c_methods,
 221         0
 222 };
 223
 224 static devclass_t radeon_atom_hw_i2c_devclass;
 225 DRIVER_MODULE_ORDERED(radeon_atom_hw_i2c, drm, radeon_atom_hw_i2c_driver,
 226     radeon_atom_hw_i2c_devclass, NULL, NULL, SI_ORDER_ANY);