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 2
  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;
  53
  54         memset(&args, 0, sizeof(args));
  55
  56         base = (unsigned char *)rdev->mode_info.atom_context->scratch;
  57
  58         if (flags & HW_I2C_WRITE) {
  59                 if (num > ATOM_MAX_HW_I2C_WRITE) {
  60                         DRM_ERROR("hw i2c: tried to write too many bytes (%d vs 2)\n", num);
  61                         return EINVAL;
  62                 }
  63                 memcpy(&out, buf, num);
  64                 args.lpI2CDataOut = cpu_to_le16(out);
  65         }
  66
  67         args.ucI2CSpeed = TARGET_HW_I2C_CLOCK;
  68         args.ucRegIndex = 0;
  69         args.ucTransBytes = num;
  70         args.ucSlaveAddr = slave_addr << 1;
  71         args.ucLineNumber = chan->rec.i2c_id;
  72
  73         atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
  74
  75         /* error */
  76         if (args.ucStatus != HW_ASSISTED_I2C_STATUS_SUCCESS) {
  77                 DRM_DEBUG_KMS("hw_i2c error\n");
  78                 return EIO;
  79         }
  80
  81         if (!(flags & HW_I2C_WRITE))
  82                 memcpy(buf, base, num);
  83
  84         return 0;
  85 }
  86
  87 static int
  88 radeon_atom_hw_i2c_xfer(device_t dev, struct iic_msg *msgs, u_int num)
  89 {
  90         struct radeon_i2c_chan *i2c = device_get_softc(dev);
  91         struct iic_msg *p;
  92         int i, remaining, current_count, buffer_offset, max_bytes, ret;
  93         u8 buf = 0, flags;
  94
  95         /* check for bus probe */
  96         p = &msgs[0];
  97         if ((num == 1) && (p->len == 0)) {
  98                 ret = radeon_process_i2c_ch(i2c,
  99                                             p->slave, HW_I2C_WRITE,
 100                                             &buf, 1);
 101                 if (ret)
 102                         return ret;
 103                 else
 104                         return (0);
 105         }
 106
 107         for (i = 0; i < num; i++) {
 108                 p = &msgs[i];
 109                 remaining = p->len;
 110                 buffer_offset = 0;
 111                 /* max_bytes are a limitation of ProcessI2cChannelTransaction not the hw */
 112                 if (p->flags & IIC_M_RD) {
 113                         max_bytes = ATOM_MAX_HW_I2C_READ;
 114                         flags = HW_I2C_READ;
 115                 } else {
 116                         max_bytes = ATOM_MAX_HW_I2C_WRITE;
 117                         flags = HW_I2C_WRITE;
 118                 }
 119                 while (remaining) {
 120                         if (remaining > max_bytes)
 121                                 current_count = max_bytes;
 122                         else
 123                                 current_count = remaining;
 124                         ret = radeon_process_i2c_ch(i2c,
 125                                                     p->slave, flags,
 126                                                     &p->buf[buffer_offset], current_count);
 127                         if (ret)
 128                                 return ret;
 129                         remaining -= current_count;
 130                         buffer_offset += current_count;
 131                 }
 132         }
 133
 134         return (0);
 135 }
 136
 137 static int
 138 radeon_atom_hw_i2c_probe(device_t dev)
 139 {
 140
 141         return (BUS_PROBE_SPECIFIC);
 142 }
 143
 144 static int
 145 radeon_atom_hw_i2c_attach(device_t dev)
 146 {
 147         struct radeon_i2c_chan *i2c;
 148         device_t iic_dev;
 149
 150         i2c = device_get_softc(dev);
 151         device_set_desc(dev, i2c->name);
 152
 153         /* add generic bit-banging code */
 154         iic_dev = device_add_child(dev, "iicbus", -1);
 155         if (iic_dev == NULL)
 156                 return (ENXIO);
 157         device_quiet(iic_dev);
 158
 159         /* attach and probe added child */
 160         bus_generic_attach(dev);
 161
 162         return (0);
 163 }
 164
 165 static int
 166 radeon_atom_hw_i2c_detach(device_t dev)
 167 {
 168         /* detach bit-banding code. */
 169         bus_generic_detach(dev);
 170
 171         /* delete bit-banding code. */
 172         device_delete_children(dev);
 173         return (0);
 174 }
 175
 176 static int
 177 radeon_atom_hw_i2c_reset(device_t dev, u_char speed,
 178     u_char addr, u_char *oldaddr)
 179 {
 180
 181         return (0);
 182 }
 183
 184 static device_method_t radeon_atom_hw_i2c_methods[] = {
 185         DEVMETHOD(device_probe,         radeon_atom_hw_i2c_probe),
 186         DEVMETHOD(device_attach,        radeon_atom_hw_i2c_attach),
 187         DEVMETHOD(device_detach,        radeon_atom_hw_i2c_detach),
 188         DEVMETHOD(iicbus_reset,         radeon_atom_hw_i2c_reset),
 189         DEVMETHOD(iicbus_transfer,      radeon_atom_hw_i2c_xfer),
 190         DEVMETHOD_END
 191 };
 192
 193 static driver_t radeon_atom_hw_i2c_driver = {
 194         "radeon_atom_hw_i2c",
 195         radeon_atom_hw_i2c_methods,
 196         0
 197 };
 198
 199 static devclass_t radeon_atom_hw_i2c_devclass;
 200 DRIVER_MODULE_ORDERED(radeon_atom_hw_i2c, drm, radeon_atom_hw_i2c_driver,
 201     radeon_atom_hw_i2c_devclass, 0, 0, SI_ORDER_ANY);