1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause 2 /* 3 * AMD MP2 platform driver 4 * 5 * Setup the I2C adapters enumerated in the ACPI namespace. 6 * MP2 controllers have 2 separate busses, up to 2 I2C adapters may be listed. 7 * 8 * Authors: Nehal Bakulchandra Shah <Nehal-bakulchandra.shah@amd.com> 9 * Elie Morisse <syniurge@gmail.com> 10 */ 11 12 #include <linux/acpi.h> 13 #include <linux/kernel.h> 14 #include <linux/module.h> 15 #include <linux/platform_device.h> 16 #include <linux/slab.h> 17 #include <linux/types.h> 18 19 #include "i2c-amd-mp2.h" 20 21 #define AMD_MP2_I2C_MAX_RW_LENGTH ((1 << 12) - 1) 22 #define AMD_I2C_TIMEOUT (msecs_to_jiffies(250)) 23 24 /** 25 * struct amd_i2c_dev - MP2 bus/i2c adapter context 26 * @common: shared context with the MP2 PCI driver 27 * @pdev: platform driver node 28 * @adap: i2c adapter 29 * @cmd_complete: xfer completion object 30 */ 31 struct amd_i2c_dev { 32 struct amd_i2c_common common; 33 struct platform_device *pdev; 34 struct i2c_adapter adap; 35 struct completion cmd_complete; 36 }; 37 38 #define amd_i2c_dev_common(__common) \ 39 container_of(__common, struct amd_i2c_dev, common) 40 41 static int i2c_amd_dma_map(struct amd_i2c_common *i2c_common) 42 { 43 struct device *dev_pci = &i2c_common->mp2_dev->pci_dev->dev; 44 struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common); 45 enum dma_data_direction dma_direction = 46 i2c_common->msg->flags & I2C_M_RD ? 47 DMA_FROM_DEVICE : DMA_TO_DEVICE; 48 49 i2c_common->dma_buf = i2c_get_dma_safe_msg_buf(i2c_common->msg, 0); 50 i2c_common->dma_addr = dma_map_single(dev_pci, i2c_common->dma_buf, 51 i2c_common->msg->len, 52 dma_direction); 53 54 if (unlikely(dma_mapping_error(dev_pci, i2c_common->dma_addr))) { 55 dev_err(&i2c_dev->pdev->dev, 56 "Error while mapping dma buffer %p\n", 57 i2c_common->dma_buf); 58 return -EIO; 59 } 60 61 return 0; 62 } 63 64 static void i2c_amd_dma_unmap(struct amd_i2c_common *i2c_common) 65 { 66 struct device *dev_pci = &i2c_common->mp2_dev->pci_dev->dev; 67 enum dma_data_direction dma_direction = 68 i2c_common->msg->flags & I2C_M_RD ? 69 DMA_FROM_DEVICE : DMA_TO_DEVICE; 70 71 dma_unmap_single(dev_pci, i2c_common->dma_addr, 72 i2c_common->msg->len, dma_direction); 73 74 i2c_put_dma_safe_msg_buf(i2c_common->dma_buf, i2c_common->msg, true); 75 } 76 77 static void i2c_amd_start_cmd(struct amd_i2c_dev *i2c_dev) 78 { 79 struct amd_i2c_common *i2c_common = &i2c_dev->common; 80 81 reinit_completion(&i2c_dev->cmd_complete); 82 i2c_common->cmd_success = false; 83 } 84 85 static void i2c_amd_cmd_completion(struct amd_i2c_common *i2c_common) 86 { 87 struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common); 88 union i2c_event *event = &i2c_common->eventval; 89 90 if (event->r.status == i2c_readcomplete_event) 91 dev_dbg(&i2c_dev->pdev->dev, "%s readdata:%*ph\n", 92 __func__, event->r.length, 93 i2c_common->msg->buf); 94 95 complete(&i2c_dev->cmd_complete); 96 } 97 98 static int i2c_amd_check_cmd_completion(struct amd_i2c_dev *i2c_dev) 99 { 100 struct amd_i2c_common *i2c_common = &i2c_dev->common; 101 unsigned long timeout; 102 103 timeout = wait_for_completion_timeout(&i2c_dev->cmd_complete, 104 i2c_dev->adap.timeout); 105 106 if ((i2c_common->reqcmd == i2c_read || 107 i2c_common->reqcmd == i2c_write) && 108 i2c_common->msg->len > 32) 109 i2c_amd_dma_unmap(i2c_common); 110 111 if (timeout == 0) { 112 amd_mp2_rw_timeout(i2c_common); 113 return -ETIMEDOUT; 114 } 115 116 amd_mp2_process_event(i2c_common); 117 118 if (!i2c_common->cmd_success) 119 return -EIO; 120 121 return 0; 122 } 123 124 static int i2c_amd_enable_set(struct amd_i2c_dev *i2c_dev, bool enable) 125 { 126 struct amd_i2c_common *i2c_common = &i2c_dev->common; 127 128 i2c_amd_start_cmd(i2c_dev); 129 amd_mp2_bus_enable_set(i2c_common, enable); 130 131 return i2c_amd_check_cmd_completion(i2c_dev); 132 } 133 134 static int i2c_amd_xfer_msg(struct amd_i2c_dev *i2c_dev, struct i2c_msg *pmsg) 135 { 136 struct amd_i2c_common *i2c_common = &i2c_dev->common; 137 138 i2c_amd_start_cmd(i2c_dev); 139 i2c_common->msg = pmsg; 140 141 if (pmsg->len > 32) 142 if (i2c_amd_dma_map(i2c_common)) 143 return -EIO; 144 145 if (pmsg->flags & I2C_M_RD) 146 amd_mp2_rw(i2c_common, i2c_read); 147 else 148 amd_mp2_rw(i2c_common, i2c_write); 149 150 return i2c_amd_check_cmd_completion(i2c_dev); 151 } 152 153 static int i2c_amd_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) 154 { 155 struct amd_i2c_dev *i2c_dev = i2c_get_adapdata(adap); 156 int i; 157 struct i2c_msg *pmsg; 158 int err; 159 160 /* the adapter might have been deleted while waiting for the bus lock */ 161 if (unlikely(!i2c_dev->common.mp2_dev)) 162 return -EINVAL; 163 164 amd_mp2_pm_runtime_get(i2c_dev->common.mp2_dev); 165 166 for (i = 0; i < num; i++) { 167 pmsg = &msgs[i]; 168 err = i2c_amd_xfer_msg(i2c_dev, pmsg); 169 if (err) 170 break; 171 } 172 173 amd_mp2_pm_runtime_put(i2c_dev->common.mp2_dev); 174 return err ? err : num; 175 } 176 177 static u32 i2c_amd_func(struct i2c_adapter *a) 178 { 179 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; 180 } 181 182 static const struct i2c_algorithm i2c_amd_algorithm = { 183 .master_xfer = i2c_amd_xfer, 184 .functionality = i2c_amd_func, 185 }; 186 187 #ifdef CONFIG_PM 188 static int i2c_amd_suspend(struct amd_i2c_common *i2c_common) 189 { 190 struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common); 191 192 i2c_amd_enable_set(i2c_dev, false); 193 return 0; 194 } 195 196 static int i2c_amd_resume(struct amd_i2c_common *i2c_common) 197 { 198 struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common); 199 200 return i2c_amd_enable_set(i2c_dev, true); 201 } 202 #endif 203 204 static enum speed_enum i2c_amd_get_bus_speed(struct platform_device *pdev) 205 { 206 u32 acpi_speed; 207 int i; 208 static const u32 supported_speeds[] = { 209 0, 100000, 400000, 1000000, 1400000, 3400000 210 }; 211 212 acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev); 213 /* round down to the lowest standard speed */ 214 for (i = 1; i < ARRAY_SIZE(supported_speeds); i++) { 215 if (acpi_speed < supported_speeds[i]) 216 break; 217 } 218 acpi_speed = supported_speeds[i - 1]; 219 220 switch (acpi_speed) { 221 case 100000: 222 return speed100k; 223 case 400000: 224 return speed400k; 225 case 1000000: 226 return speed1000k; 227 case 1400000: 228 return speed1400k; 229 case 3400000: 230 return speed3400k; 231 default: 232 return speed400k; 233 } 234 } 235 236 static const struct i2c_adapter_quirks amd_i2c_dev_quirks = { 237 .max_read_len = AMD_MP2_I2C_MAX_RW_LENGTH, 238 .max_write_len = AMD_MP2_I2C_MAX_RW_LENGTH, 239 }; 240 241 static int i2c_amd_probe(struct platform_device *pdev) 242 { 243 int ret; 244 struct amd_i2c_dev *i2c_dev; 245 acpi_handle handle = ACPI_HANDLE(&pdev->dev); 246 struct acpi_device *adev; 247 struct amd_mp2_dev *mp2_dev; 248 const char *uid; 249 250 if (acpi_bus_get_device(handle, &adev)) 251 return -ENODEV; 252 253 /* The ACPI namespace doesn't contain information about which MP2 PCI 254 * device an AMDI0011 ACPI device is related to, so assume that there's 255 * only one MP2 PCI device per system. 256 */ 257 mp2_dev = amd_mp2_find_device(); 258 if (!mp2_dev || !mp2_dev->probed) 259 /* The MP2 PCI device should get probed later */ 260 return -EPROBE_DEFER; 261 262 i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL); 263 if (!i2c_dev) 264 return -ENOMEM; 265 266 i2c_dev->common.mp2_dev = mp2_dev; 267 i2c_dev->pdev = pdev; 268 platform_set_drvdata(pdev, i2c_dev); 269 270 i2c_dev->common.cmd_completion = &i2c_amd_cmd_completion; 271 #ifdef CONFIG_PM 272 i2c_dev->common.suspend = &i2c_amd_suspend; 273 i2c_dev->common.resume = &i2c_amd_resume; 274 #endif 275 276 uid = adev->pnp.unique_id; 277 if (!uid) { 278 dev_err(&pdev->dev, "missing UID/bus id!\n"); 279 return -EINVAL; 280 } else if (strcmp(uid, "0") == 0) { 281 i2c_dev->common.bus_id = 0; 282 } else if (strcmp(uid, "1") == 0) { 283 i2c_dev->common.bus_id = 1; 284 } else { 285 dev_err(&pdev->dev, "incorrect UID/bus id \"%s\"!\n", uid); 286 return -EINVAL; 287 } 288 dev_dbg(&pdev->dev, "bus id is %u\n", i2c_dev->common.bus_id); 289 290 /* Register the adapter */ 291 amd_mp2_pm_runtime_get(mp2_dev); 292 293 i2c_dev->common.reqcmd = i2c_none; 294 if (amd_mp2_register_cb(&i2c_dev->common)) 295 return -EINVAL; 296 device_link_add(&i2c_dev->pdev->dev, &mp2_dev->pci_dev->dev, 297 DL_FLAG_AUTOREMOVE_CONSUMER); 298 299 i2c_dev->common.i2c_speed = i2c_amd_get_bus_speed(pdev); 300 301 /* Setup i2c adapter description */ 302 i2c_dev->adap.owner = THIS_MODULE; 303 i2c_dev->adap.algo = &i2c_amd_algorithm; 304 i2c_dev->adap.quirks = &amd_i2c_dev_quirks; 305 i2c_dev->adap.dev.parent = &pdev->dev; 306 i2c_dev->adap.algo_data = i2c_dev; 307 i2c_dev->adap.timeout = AMD_I2C_TIMEOUT; 308 ACPI_COMPANION_SET(&i2c_dev->adap.dev, ACPI_COMPANION(&pdev->dev)); 309 i2c_dev->adap.dev.of_node = pdev->dev.of_node; 310 snprintf(i2c_dev->adap.name, sizeof(i2c_dev->adap.name), 311 "AMD MP2 i2c bus %u", i2c_dev->common.bus_id); 312 i2c_set_adapdata(&i2c_dev->adap, i2c_dev); 313 314 init_completion(&i2c_dev->cmd_complete); 315 316 /* Enable the bus */ 317 if (i2c_amd_enable_set(i2c_dev, true)) 318 dev_err(&pdev->dev, "initial bus enable failed\n"); 319 320 /* Attach to the i2c layer */ 321 ret = i2c_add_adapter(&i2c_dev->adap); 322 323 amd_mp2_pm_runtime_put(mp2_dev); 324 325 if (ret < 0) 326 dev_err(&pdev->dev, "i2c add adapter failed = %d\n", ret); 327 328 return ret; 329 } 330 331 static int i2c_amd_remove(struct platform_device *pdev) 332 { 333 struct amd_i2c_dev *i2c_dev = platform_get_drvdata(pdev); 334 struct amd_i2c_common *i2c_common = &i2c_dev->common; 335 336 i2c_lock_bus(&i2c_dev->adap, I2C_LOCK_ROOT_ADAPTER); 337 338 i2c_amd_enable_set(i2c_dev, false); 339 amd_mp2_unregister_cb(i2c_common); 340 i2c_common->mp2_dev = NULL; 341 342 i2c_unlock_bus(&i2c_dev->adap, I2C_LOCK_ROOT_ADAPTER); 343 344 i2c_del_adapter(&i2c_dev->adap); 345 return 0; 346 } 347 348 static const struct acpi_device_id i2c_amd_acpi_match[] = { 349 { "AMDI0011" }, 350 { }, 351 }; 352 MODULE_DEVICE_TABLE(acpi, i2c_amd_acpi_match); 353 354 static struct platform_driver i2c_amd_plat_driver = { 355 .probe = i2c_amd_probe, 356 .remove = i2c_amd_remove, 357 .driver = { 358 .name = "i2c_amd_mp2", 359 .acpi_match_table = ACPI_PTR(i2c_amd_acpi_match), 360 }, 361 }; 362 module_platform_driver(i2c_amd_plat_driver); 363 364 MODULE_DESCRIPTION("AMD(R) MP2 I2C Platform Driver"); 365 MODULE_AUTHOR("Nehal Shah <nehal-bakulchandra.shah@amd.com>"); 366 MODULE_AUTHOR("Elie Morisse <syniurge@gmail.com>"); 367 MODULE_LICENSE("Dual BSD/GPL"); 368