drivers/gpu/drm/radeon/radeon_dp_auxch.c

   1 /*
   2  * Copyright 2015 Red Hat 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: Dave Airlie
  23  */
  24 #include <drm/drmP.h>
  25 #include <drm/radeon_drm.h>
  26 #include "radeon.h"
  27 #include "nid.h"
  28
  29 #define AUX_RX_ERROR_FLAGS (AUX_SW_RX_OVERFLOW |             \
  30                             AUX_SW_RX_HPD_DISCON |           \
  31                             AUX_SW_RX_PARTIAL_BYTE |         \
  32                             AUX_SW_NON_AUX_MODE |            \
  33                             AUX_SW_RX_SYNC_INVALID_L |       \
  34                             AUX_SW_RX_SYNC_INVALID_H |       \
  35                             AUX_SW_RX_INVALID_START |        \
  36                             AUX_SW_RX_RECV_NO_DET |          \
  37                             AUX_SW_RX_RECV_INVALID_H |       \
  38                             AUX_SW_RX_RECV_INVALID_V)
  39
  40 #define AUX_SW_REPLY_GET_BYTE_COUNT(x) (((x) >> 24) & 0x1f)
  41
  42 #define BARE_ADDRESS_SIZE 3
  43
  44 static const u32 aux_offset[] =
  45 {
  46         0x6200 - 0x6200,
  47         0x6250 - 0x6200,
  48         0x62a0 - 0x6200,
  49         0x6300 - 0x6200,
  50         0x6350 - 0x6200,
  51         0x63a0 - 0x6200,
  52 };
  53
  54 ssize_t
  55 radeon_dp_aux_transfer_native(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
  56 {
  57         struct radeon_i2c_chan *chan =
  58                 container_of(aux, struct radeon_i2c_chan, aux);
  59         struct drm_device *dev = chan->dev;
  60         struct radeon_device *rdev = dev->dev_private;
  61         int ret = 0, i;
  62         uint32_t tmp, ack = 0;
  63         int instance = chan->rec.i2c_id & 0xf;
  64         u8 byte;
  65         u8 *buf = msg->buffer;
  66         int retry_count = 0;
  67         int bytes;
  68         int msize;
  69         bool is_write = false;
  70
  71         if (WARN_ON(msg->size > 16))
  72                 return -E2BIG;
  73
  74         switch (msg->request & ~DP_AUX_I2C_MOT) {
  75         case DP_AUX_NATIVE_WRITE:
  76         case DP_AUX_I2C_WRITE:
  77                 is_write = true;
  78                 break;
  79         case DP_AUX_NATIVE_READ:
  80         case DP_AUX_I2C_READ:
  81                 break;
  82         default:
  83                 return -EINVAL;
  84         }
  85
  86         /* work out two sizes required */
  87         msize = 0;
  88         bytes = BARE_ADDRESS_SIZE;
  89         if (msg->size) {
  90                 msize = msg->size - 1;
  91                 bytes++;
  92                 if (is_write)
  93                         bytes += msg->size;
  94         }
  95
  96         mutex_lock(&chan->mutex);
  97
  98         /* switch the pad to aux mode */
  99         tmp = RREG32(chan->rec.mask_clk_reg);
 100         tmp |= (1 << 16);
 101         WREG32(chan->rec.mask_clk_reg, tmp);
 102
 103         /* setup AUX control register with correct HPD pin */
 104         tmp = RREG32(AUX_CONTROL + aux_offset[instance]);
 105
 106         tmp &= AUX_HPD_SEL(0x7);
 107         tmp |= AUX_HPD_SEL(chan->rec.hpd);
 108         tmp |= AUX_EN | AUX_LS_READ_EN;
 109
 110         WREG32(AUX_CONTROL + aux_offset[instance], tmp);
 111
 112         /* atombios appears to write this twice lets copy it */
 113         WREG32(AUX_SW_CONTROL + aux_offset[instance],
 114                AUX_SW_WR_BYTES(bytes));
 115         WREG32(AUX_SW_CONTROL + aux_offset[instance],
 116                AUX_SW_WR_BYTES(bytes));
 117
 118         /* write the data header into the registers */
 119         /* request, address, msg size */
 120         byte = (msg->request << 4) | ((msg->address >> 16) & 0xf);
 121         WREG32(AUX_SW_DATA + aux_offset[instance],
 122                AUX_SW_DATA_MASK(byte) | AUX_SW_AUTOINCREMENT_DISABLE);
 123
 124         byte = (msg->address >> 8) & 0xff;
 125         WREG32(AUX_SW_DATA + aux_offset[instance],
 126                AUX_SW_DATA_MASK(byte));
 127
 128         byte = msg->address & 0xff;
 129         WREG32(AUX_SW_DATA + aux_offset[instance],
 130                AUX_SW_DATA_MASK(byte));
 131
 132         byte = msize;
 133         WREG32(AUX_SW_DATA + aux_offset[instance],
 134                AUX_SW_DATA_MASK(byte));
 135
 136         /* if we are writing - write the msg buffer */
 137         if (is_write) {
 138                 for (i = 0; i < msg->size; i++) {
 139                         WREG32(AUX_SW_DATA + aux_offset[instance],
 140                                AUX_SW_DATA_MASK(buf[i]));
 141                 }
 142         }
 143
 144         /* clear the ACK */
 145         WREG32(AUX_SW_INTERRUPT_CONTROL + aux_offset[instance], AUX_SW_DONE_ACK);
 146
 147         /* write the size and GO bits */
 148         WREG32(AUX_SW_CONTROL + aux_offset[instance],
 149                AUX_SW_WR_BYTES(bytes) | AUX_SW_GO);
 150
 151         /* poll the status registers - TODO irq support */
 152         do {
 153                 tmp = RREG32(AUX_SW_STATUS + aux_offset[instance]);
 154                 if (tmp & AUX_SW_DONE) {
 155                         break;
 156                 }
 157                 usleep_range(100, 200);
 158         } while (retry_count++ < 1000);
 159
 160         if (retry_count >= 1000) {
 161                 DRM_ERROR("auxch hw never signalled completion, error %08x\n", tmp);
 162                 ret = -EIO;
 163                 goto done;
 164         }
 165
 166         if (tmp & AUX_SW_RX_TIMEOUT) {
 167                 ret = -ETIMEDOUT;
 168                 goto done;
 169         }
 170         if (tmp & AUX_RX_ERROR_FLAGS) {
 171                 DRM_DEBUG_KMS_RATELIMITED("dp_aux_ch flags not zero: %08x\n",
 172                                           tmp);
 173                 ret = -EIO;
 174                 goto done;
 175         }
 176
 177         bytes = AUX_SW_REPLY_GET_BYTE_COUNT(tmp);
 178         if (bytes) {
 179                 WREG32(AUX_SW_DATA + aux_offset[instance],
 180                        AUX_SW_DATA_RW | AUX_SW_AUTOINCREMENT_DISABLE);
 181
 182                 tmp = RREG32(AUX_SW_DATA + aux_offset[instance]);
 183                 ack = (tmp >> 8) & 0xff;
 184
 185                 for (i = 0; i < bytes - 1; i++) {
 186                         tmp = RREG32(AUX_SW_DATA + aux_offset[instance]);
 187                         if (buf)
 188                                 buf[i] = (tmp >> 8) & 0xff;
 189                 }
 190                 if (buf)
 191                         ret = bytes - 1;
 192         }
 193
 194         WREG32(AUX_SW_INTERRUPT_CONTROL + aux_offset[instance], AUX_SW_DONE_ACK);
 195
 196         if (is_write)
 197                 ret = msg->size;
 198 done:
 199         mutex_unlock(&chan->mutex);
 200
 201         if (ret >= 0)
 202                 msg->reply = ack >> 4;
 203         return ret;
 204 }