drivers/gpu/drm/amd/amdgpu/amdgpu_i2c.c

   1 /*
   2  * Copyright 2007-8 Advanced Micro Devices, Inc.
   3  * Copyright 2008 Red Hat Inc.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9  * and/or sell copies of the Software, and to permit persons to whom the
  10  * Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be included in
  13  * all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
  19  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  20  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  21  * OTHER DEALINGS IN THE SOFTWARE.
  22  *
  23  * Authors: Dave Airlie
  24  *          Alex Deucher
  25  */
  26 #include <linux/export.h>
  27
  28 #include <drm/drmP.h>
  29 #include <drm/drm_edid.h>
  30 #include <drm/amdgpu_drm.h>
  31 #include "amdgpu.h"
  32 #include "amdgpu_i2c.h"
  33 #include "amdgpu_atombios.h"
  34 #include "atom.h"
  35 #include "atombios_dp.h"
  36 #include "atombios_i2c.h"
  37
  38 /* bit banging i2c */
  39 static int amdgpu_i2c_pre_xfer(struct i2c_adapter *i2c_adap)
  40 {
  41         struct amdgpu_i2c_chan *i2c = i2c_get_adapdata(i2c_adap);
  42         struct amdgpu_device *adev = i2c->dev->dev_private;
  43         struct amdgpu_i2c_bus_rec *rec = &i2c->rec;
  44         uint32_t temp;
  45
  46         mutex_lock(&i2c->mutex);
  47
  48         /* switch the pads to ddc mode */
  49         if (rec->hw_capable) {
  50                 temp = RREG32(rec->mask_clk_reg);
  51                 temp &= ~(1 << 16);
  52                 WREG32(rec->mask_clk_reg, temp);
  53         }
  54
  55         /* clear the output pin values */
  56         temp = RREG32(rec->a_clk_reg) & ~rec->a_clk_mask;
  57         WREG32(rec->a_clk_reg, temp);
  58
  59         temp = RREG32(rec->a_data_reg) & ~rec->a_data_mask;
  60         WREG32(rec->a_data_reg, temp);
  61
  62         /* set the pins to input */
  63         temp = RREG32(rec->en_clk_reg) & ~rec->en_clk_mask;
  64         WREG32(rec->en_clk_reg, temp);
  65
  66         temp = RREG32(rec->en_data_reg) & ~rec->en_data_mask;
  67         WREG32(rec->en_data_reg, temp);
  68
  69         /* mask the gpio pins for software use */
  70         temp = RREG32(rec->mask_clk_reg) | rec->mask_clk_mask;
  71         WREG32(rec->mask_clk_reg, temp);
  72         temp = RREG32(rec->mask_clk_reg);
  73
  74         temp = RREG32(rec->mask_data_reg) | rec->mask_data_mask;
  75         WREG32(rec->mask_data_reg, temp);
  76         temp = RREG32(rec->mask_data_reg);
  77
  78         return 0;
  79 }
  80
  81 static void amdgpu_i2c_post_xfer(struct i2c_adapter *i2c_adap)
  82 {
  83         struct amdgpu_i2c_chan *i2c = i2c_get_adapdata(i2c_adap);
  84         struct amdgpu_device *adev = i2c->dev->dev_private;
  85         struct amdgpu_i2c_bus_rec *rec = &i2c->rec;
  86         uint32_t temp;
  87
  88         /* unmask the gpio pins for software use */
  89         temp = RREG32(rec->mask_clk_reg) & ~rec->mask_clk_mask;
  90         WREG32(rec->mask_clk_reg, temp);
  91         temp = RREG32(rec->mask_clk_reg);
  92
  93         temp = RREG32(rec->mask_data_reg) & ~rec->mask_data_mask;
  94         WREG32(rec->mask_data_reg, temp);
  95         temp = RREG32(rec->mask_data_reg);
  96
  97         mutex_unlock(&i2c->mutex);
  98 }
  99
 100 static int amdgpu_i2c_get_clock(void *i2c_priv)
 101 {
 102         struct amdgpu_i2c_chan *i2c = i2c_priv;
 103         struct amdgpu_device *adev = i2c->dev->dev_private;
 104         struct amdgpu_i2c_bus_rec *rec = &i2c->rec;
 105         uint32_t val;
 106
 107         /* read the value off the pin */
 108         val = RREG32(rec->y_clk_reg);
 109         val &= rec->y_clk_mask;
 110
 111         return (val != 0);
 112 }
 113
 114
 115 static int amdgpu_i2c_get_data(void *i2c_priv)
 116 {
 117         struct amdgpu_i2c_chan *i2c = i2c_priv;
 118         struct amdgpu_device *adev = i2c->dev->dev_private;
 119         struct amdgpu_i2c_bus_rec *rec = &i2c->rec;
 120         uint32_t val;
 121
 122         /* read the value off the pin */
 123         val = RREG32(rec->y_data_reg);
 124         val &= rec->y_data_mask;
 125
 126         return (val != 0);
 127 }
 128
 129 static void amdgpu_i2c_set_clock(void *i2c_priv, int clock)
 130 {
 131         struct amdgpu_i2c_chan *i2c = i2c_priv;
 132         struct amdgpu_device *adev = i2c->dev->dev_private;
 133         struct amdgpu_i2c_bus_rec *rec = &i2c->rec;
 134         uint32_t val;
 135
 136         /* set pin direction */
 137         val = RREG32(rec->en_clk_reg) & ~rec->en_clk_mask;
 138         val |= clock ? 0 : rec->en_clk_mask;
 139         WREG32(rec->en_clk_reg, val);
 140 }
 141
 142 static void amdgpu_i2c_set_data(void *i2c_priv, int data)
 143 {
 144         struct amdgpu_i2c_chan *i2c = i2c_priv;
 145         struct amdgpu_device *adev = i2c->dev->dev_private;
 146         struct amdgpu_i2c_bus_rec *rec = &i2c->rec;
 147         uint32_t val;
 148
 149         /* set pin direction */
 150         val = RREG32(rec->en_data_reg) & ~rec->en_data_mask;
 151         val |= data ? 0 : rec->en_data_mask;
 152         WREG32(rec->en_data_reg, val);
 153 }
 154
 155 static const struct i2c_algorithm amdgpu_atombios_i2c_algo = {
 156         .master_xfer = amdgpu_atombios_i2c_xfer,
 157         .functionality = amdgpu_atombios_i2c_func,
 158 };
 159
 160 struct amdgpu_i2c_chan *amdgpu_i2c_create(struct drm_device *dev,
 161                                             struct amdgpu_i2c_bus_rec *rec,
 162                                             const char *name)
 163 {
 164         struct amdgpu_i2c_chan *i2c;
 165         int ret;
 166
 167         /* don't add the mm_i2c bus unless hw_i2c is enabled */
 168         if (rec->mm_i2c && (amdgpu_hw_i2c == 0))
 169                 return NULL;
 170
 171         i2c = kzalloc(sizeof(struct amdgpu_i2c_chan), GFP_KERNEL);
 172         if (i2c == NULL)
 173                 return NULL;
 174
 175         i2c->rec = *rec;
 176         i2c->adapter.owner = THIS_MODULE;
 177         i2c->adapter.class = I2C_CLASS_DDC;
 178         i2c->adapter.dev.parent = &dev->pdev->dev;
 179         i2c->dev = dev;
 180         i2c_set_adapdata(&i2c->adapter, i2c);
 181         mutex_init(&i2c->mutex);
 182         if (rec->hw_capable &&
 183             amdgpu_hw_i2c) {
 184                 /* hw i2c using atom */
 185                 snprintf(i2c->adapter.name, sizeof(i2c->adapter.name),
 186                          "AMDGPU i2c hw bus %s", name);
 187                 i2c->adapter.algo = &amdgpu_atombios_i2c_algo;
 188                 ret = i2c_add_adapter(&i2c->adapter);
 189                 if (ret) {
 190                         DRM_ERROR("Failed to register hw i2c %s\n", name);
 191                         goto out_free;
 192                 }
 193         } else {
 194                 /* set the amdgpu bit adapter */
 195                 snprintf(i2c->adapter.name, sizeof(i2c->adapter.name),
 196                          "AMDGPU i2c bit bus %s", name);
 197                 i2c->adapter.algo_data = &i2c->bit;
 198                 i2c->bit.pre_xfer = amdgpu_i2c_pre_xfer;
 199                 i2c->bit.post_xfer = amdgpu_i2c_post_xfer;
 200                 i2c->bit.setsda = amdgpu_i2c_set_data;
 201                 i2c->bit.setscl = amdgpu_i2c_set_clock;
 202                 i2c->bit.getsda = amdgpu_i2c_get_data;
 203                 i2c->bit.getscl = amdgpu_i2c_get_clock;
 204                 i2c->bit.udelay = 10;
 205                 i2c->bit.timeout = usecs_to_jiffies(2200);      /* from VESA */
 206                 i2c->bit.data = i2c;
 207                 ret = i2c_bit_add_bus(&i2c->adapter);
 208                 if (ret) {
 209                         DRM_ERROR("Failed to register bit i2c %s\n", name);
 210                         goto out_free;
 211                 }
 212         }
 213
 214         return i2c;
 215 out_free:
 216         kfree(i2c);
 217         return NULL;
 218
 219 }
 220
 221 void amdgpu_i2c_destroy(struct amdgpu_i2c_chan *i2c)
 222 {
 223         if (!i2c)
 224                 return;
 225         i2c_del_adapter(&i2c->adapter);
 226         kfree(i2c);
 227 }
 228
 229 /* Add the default buses */
 230 void amdgpu_i2c_init(struct amdgpu_device *adev)
 231 {
 232         if (amdgpu_hw_i2c)
 233                 DRM_INFO("hw_i2c forced on, you may experience display detection problems!\n");
 234
 235         if (adev->is_atom_bios)
 236                 amdgpu_atombios_i2c_init(adev);
 237 }
 238
 239 /* remove all the buses */
 240 void amdgpu_i2c_fini(struct amdgpu_device *adev)
 241 {
 242         int i;
 243
 244         for (i = 0; i < AMDGPU_MAX_I2C_BUS; i++) {
 245                 if (adev->i2c_bus[i]) {
 246                         amdgpu_i2c_destroy(adev->i2c_bus[i]);
 247                         adev->i2c_bus[i] = NULL;
 248                 }
 249         }
 250 }
 251
 252 /* Add additional buses */
 253 void amdgpu_i2c_add(struct amdgpu_device *adev,
 254                      struct amdgpu_i2c_bus_rec *rec,
 255                      const char *name)
 256 {
 257         struct drm_device *dev = adev->ddev;
 258         int i;
 259
 260         for (i = 0; i < AMDGPU_MAX_I2C_BUS; i++) {
 261                 if (!adev->i2c_bus[i]) {
 262                         adev->i2c_bus[i] = amdgpu_i2c_create(dev, rec, name);
 263                         return;
 264                 }
 265         }
 266 }
 267
 268 /* looks up bus based on id */
 269 struct amdgpu_i2c_chan *
 270 amdgpu_i2c_lookup(struct amdgpu_device *adev,
 271                    struct amdgpu_i2c_bus_rec *i2c_bus)
 272 {
 273         int i;
 274
 275         for (i = 0; i < AMDGPU_MAX_I2C_BUS; i++) {
 276                 if (adev->i2c_bus[i] &&
 277                     (adev->i2c_bus[i]->rec.i2c_id == i2c_bus->i2c_id)) {
 278                         return adev->i2c_bus[i];
 279                 }
 280         }
 281         return NULL;
 282 }
 283
 284 static void amdgpu_i2c_get_byte(struct amdgpu_i2c_chan *i2c_bus,
 285                                  u8 slave_addr,
 286                                  u8 addr,
 287                                  u8 *val)
 288 {
 289         u8 out_buf[2];
 290         u8 in_buf[2];
 291         struct i2c_msg msgs[] = {
 292                 {
 293                         .addr = slave_addr,
 294                         .flags = 0,
 295                         .len = 1,
 296                         .buf = out_buf,
 297                 },
 298                 {
 299                         .addr = slave_addr,
 300                         .flags = I2C_M_RD,
 301                         .len = 1,
 302                         .buf = in_buf,
 303                 }
 304         };
 305
 306         out_buf[0] = addr;
 307         out_buf[1] = 0;
 308
 309         if (i2c_transfer(&i2c_bus->adapter, msgs, 2) == 2) {
 310                 *val = in_buf[0];
 311                 DRM_DEBUG("val = 0x%02x\n", *val);
 312         } else {
 313                 DRM_DEBUG("i2c 0x%02x 0x%02x read failed\n",
 314                           addr, *val);
 315         }
 316 }
 317
 318 static void amdgpu_i2c_put_byte(struct amdgpu_i2c_chan *i2c_bus,
 319                                  u8 slave_addr,
 320                                  u8 addr,
 321                                  u8 val)
 322 {
 323         uint8_t out_buf[2];
 324         struct i2c_msg msg = {
 325                 .addr = slave_addr,
 326                 .flags = 0,
 327                 .len = 2,
 328                 .buf = out_buf,
 329         };
 330
 331         out_buf[0] = addr;
 332         out_buf[1] = val;
 333
 334         if (i2c_transfer(&i2c_bus->adapter, &msg, 1) != 1)
 335                 DRM_DEBUG("i2c 0x%02x 0x%02x write failed\n",
 336                           addr, val);
 337 }
 338
 339 /* ddc router switching */
 340 void
 341 amdgpu_i2c_router_select_ddc_port(struct amdgpu_connector *amdgpu_connector)
 342 {
 343         u8 val;
 344
 345         if (!amdgpu_connector->router.ddc_valid)
 346                 return;
 347
 348         if (!amdgpu_connector->router_bus)
 349                 return;
 350
 351         amdgpu_i2c_get_byte(amdgpu_connector->router_bus,
 352                             amdgpu_connector->router.i2c_addr,
 353                             0x3, &val);
 354         val &= ~amdgpu_connector->router.ddc_mux_control_pin;
 355         amdgpu_i2c_put_byte(amdgpu_connector->router_bus,
 356                             amdgpu_connector->router.i2c_addr,
 357                             0x3, val);
 358         amdgpu_i2c_get_byte(amdgpu_connector->router_bus,
 359                             amdgpu_connector->router.i2c_addr,
 360                             0x1, &val);
 361         val &= ~amdgpu_connector->router.ddc_mux_control_pin;
 362         val |= amdgpu_connector->router.ddc_mux_state;
 363         amdgpu_i2c_put_byte(amdgpu_connector->router_bus,
 364                             amdgpu_connector->router.i2c_addr,
 365                             0x1, val);
 366 }
 367
 368 /* clock/data router switching */
 369 void
 370 amdgpu_i2c_router_select_cd_port(struct amdgpu_connector *amdgpu_connector)
 371 {
 372         u8 val;
 373
 374         if (!amdgpu_connector->router.cd_valid)
 375                 return;
 376
 377         if (!amdgpu_connector->router_bus)
 378                 return;
 379
 380         amdgpu_i2c_get_byte(amdgpu_connector->router_bus,
 381                             amdgpu_connector->router.i2c_addr,
 382                             0x3, &val);
 383         val &= ~amdgpu_connector->router.cd_mux_control_pin;
 384         amdgpu_i2c_put_byte(amdgpu_connector->router_bus,
 385                             amdgpu_connector->router.i2c_addr,
 386                             0x3, val);
 387         amdgpu_i2c_get_byte(amdgpu_connector->router_bus,
 388                             amdgpu_connector->router.i2c_addr,
 389                             0x1, &val);
 390         val &= ~amdgpu_connector->router.cd_mux_control_pin;
 391         val |= amdgpu_connector->router.cd_mux_state;
 392         amdgpu_i2c_put_byte(amdgpu_connector->router_bus,
 393                             amdgpu_connector->router.i2c_addr,
 394                             0x1, val);
 395 }