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