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, "readdata:%*ph\n", event->r.length, 92 i2c_common->msg->buf); 93 94 complete(&i2c_dev->cmd_complete); 95 } 96 97 static int i2c_amd_check_cmd_completion(struct amd_i2c_dev *i2c_dev) 98 { 99 struct amd_i2c_common *i2c_common = &i2c_dev->common; 100 unsigned long time_left; 101 102 time_left = wait_for_completion_timeout(&i2c_dev->cmd_complete, 103 i2c_dev->adap.timeout); 104 105 if ((i2c_common->reqcmd == i2c_read || 106 i2c_common->reqcmd == i2c_write) && 107 i2c_common->msg->len > 32) 108 i2c_amd_dma_unmap(i2c_common); 109 110 if (time_left == 0) { 111 amd_mp2_rw_timeout(i2c_common); 112 return -ETIMEDOUT; 113 } 114 115 amd_mp2_process_event(i2c_common); 116 117 if (!i2c_common->cmd_success) 118 return -EIO; 119 120 return 0; 121 } 122 123 static int i2c_amd_enable_set(struct amd_i2c_dev *i2c_dev, bool enable) 124 { 125 struct amd_i2c_common *i2c_common = &i2c_dev->common; 126 127 i2c_amd_start_cmd(i2c_dev); 128 amd_mp2_bus_enable_set(i2c_common, enable); 129 130 return i2c_amd_check_cmd_completion(i2c_dev); 131 } 132 133 static int i2c_amd_xfer_msg(struct amd_i2c_dev *i2c_dev, struct i2c_msg *pmsg) 134 { 135 struct amd_i2c_common *i2c_common = &i2c_dev->common; 136 137 i2c_amd_start_cmd(i2c_dev); 138 i2c_common->msg = pmsg; 139 140 if (pmsg->len > 32) 141 if (i2c_amd_dma_map(i2c_common)) 142 return -EIO; 143 144 if (pmsg->flags & I2C_M_RD) 145 amd_mp2_rw(i2c_common, i2c_read); 146 else 147 amd_mp2_rw(i2c_common, i2c_write); 148 149 return i2c_amd_check_cmd_completion(i2c_dev); 150 } 151 152 static int i2c_amd_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) 153 { 154 struct amd_i2c_dev *i2c_dev = i2c_get_adapdata(adap); 155 int i; 156 struct i2c_msg *pmsg; 157 int err = 0; 158 159 /* the adapter might have been deleted while waiting for the bus lock */ 160 if (unlikely(!i2c_dev->common.mp2_dev)) 161 return -EINVAL; 162 163 amd_mp2_pm_runtime_get(i2c_dev->common.mp2_dev); 164 165 for (i = 0; i < num; i++) { 166 pmsg = &msgs[i]; 167 err = i2c_amd_xfer_msg(i2c_dev, pmsg); 168 if (err) 169 break; 170 } 171 172 amd_mp2_pm_runtime_put(i2c_dev->common.mp2_dev); 173 return err ? err : num; 174 } 175 176 static u32 i2c_amd_func(struct i2c_adapter *a) 177 { 178 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; 179 } 180 181 static const struct i2c_algorithm i2c_amd_algorithm = { 182 .master_xfer = i2c_amd_xfer, 183 .functionality = i2c_amd_func, 184 }; 185 186 #ifdef CONFIG_PM 187 static int i2c_amd_suspend(struct amd_i2c_common *i2c_common) 188 { 189 struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common); 190 191 i2c_amd_enable_set(i2c_dev, false); 192 return 0; 193 } 194 195 static int i2c_amd_resume(struct amd_i2c_common *i2c_common) 196 { 197 struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common); 198 199 return i2c_amd_enable_set(i2c_dev, true); 200 } 201 #endif 202 203 static const u32 supported_speeds[] = { 204 I2C_MAX_HIGH_SPEED_MODE_FREQ, 205 I2C_MAX_TURBO_MODE_FREQ, 206 I2C_MAX_FAST_MODE_PLUS_FREQ, 207 I2C_MAX_FAST_MODE_FREQ, 208 I2C_MAX_STANDARD_MODE_FREQ, 209 }; 210 211 static enum speed_enum i2c_amd_get_bus_speed(struct platform_device *pdev) 212 { 213 u32 acpi_speed; 214 int i; 215 216 acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev); 217 /* round down to the lowest standard speed */ 218 for (i = 0; i < ARRAY_SIZE(supported_speeds); i++) { 219 if (acpi_speed >= supported_speeds[i]) 220 break; 221 } 222 acpi_speed = i < ARRAY_SIZE(supported_speeds) ? supported_speeds[i] : 0; 223 224 switch (acpi_speed) { 225 case I2C_MAX_STANDARD_MODE_FREQ: 226 return speed100k; 227 case I2C_MAX_FAST_MODE_FREQ: 228 return speed400k; 229 case I2C_MAX_FAST_MODE_PLUS_FREQ: 230 return speed1000k; 231 case I2C_MAX_TURBO_MODE_FREQ: 232 return speed1400k; 233 case I2C_MAX_HIGH_SPEED_MODE_FREQ: 234 return speed3400k; 235 default: 236 return speed400k; 237 } 238 } 239 240 static const struct i2c_adapter_quirks amd_i2c_dev_quirks = { 241 .max_read_len = AMD_MP2_I2C_MAX_RW_LENGTH, 242 .max_write_len = AMD_MP2_I2C_MAX_RW_LENGTH, 243 }; 244 245 static int i2c_amd_probe(struct platform_device *pdev) 246 { 247 struct device *dev = &pdev->dev; 248 int ret; 249 struct amd_i2c_dev *i2c_dev; 250 struct amd_mp2_dev *mp2_dev; 251 u64 uid; 252 253 ret = acpi_dev_uid_to_integer(ACPI_COMPANION(dev), &uid); 254 if (ret) 255 return dev_err_probe(dev, ret, "missing UID/bus id!\n"); 256 if (uid >= 2) 257 return dev_err_probe(dev, -EINVAL, "incorrect UID/bus id \"%llu\"!\n", uid); 258 dev_dbg(dev, "bus id is %llu\n", uid); 259 260 /* The ACPI namespace doesn't contain information about which MP2 PCI 261 * device an AMDI0011 ACPI device is related to, so assume that there's 262 * only one MP2 PCI device per system. 263 */ 264 mp2_dev = amd_mp2_find_device(); 265 if (!mp2_dev || !mp2_dev->probed) 266 /* The MP2 PCI device should get probed later */ 267 return -EPROBE_DEFER; 268 269 i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL); 270 if (!i2c_dev) 271 return -ENOMEM; 272 273 i2c_dev->common.bus_id = uid; 274 i2c_dev->common.mp2_dev = mp2_dev; 275 i2c_dev->pdev = pdev; 276 platform_set_drvdata(pdev, i2c_dev); 277 278 i2c_dev->common.cmd_completion = &i2c_amd_cmd_completion; 279 #ifdef CONFIG_PM 280 i2c_dev->common.suspend = &i2c_amd_suspend; 281 i2c_dev->common.resume = &i2c_amd_resume; 282 #endif 283 284 /* Register the adapter */ 285 amd_mp2_pm_runtime_get(mp2_dev); 286 287 i2c_dev->common.reqcmd = i2c_none; 288 if (amd_mp2_register_cb(&i2c_dev->common)) 289 return -EINVAL; 290 device_link_add(&i2c_dev->pdev->dev, &mp2_dev->pci_dev->dev, 291 DL_FLAG_AUTOREMOVE_CONSUMER); 292 293 i2c_dev->common.i2c_speed = i2c_amd_get_bus_speed(pdev); 294 295 /* Setup i2c adapter description */ 296 i2c_dev->adap.owner = THIS_MODULE; 297 i2c_dev->adap.algo = &i2c_amd_algorithm; 298 i2c_dev->adap.quirks = &amd_i2c_dev_quirks; 299 i2c_dev->adap.dev.parent = &pdev->dev; 300 i2c_dev->adap.algo_data = i2c_dev; 301 i2c_dev->adap.timeout = AMD_I2C_TIMEOUT; 302 ACPI_COMPANION_SET(&i2c_dev->adap.dev, ACPI_COMPANION(&pdev->dev)); 303 i2c_dev->adap.dev.of_node = pdev->dev.of_node; 304 snprintf(i2c_dev->adap.name, sizeof(i2c_dev->adap.name), 305 "AMD MP2 i2c bus %u", i2c_dev->common.bus_id); 306 i2c_set_adapdata(&i2c_dev->adap, i2c_dev); 307 308 init_completion(&i2c_dev->cmd_complete); 309 310 /* Enable the bus */ 311 if (i2c_amd_enable_set(i2c_dev, true)) 312 dev_err(&pdev->dev, "initial bus enable failed\n"); 313 314 /* Attach to the i2c layer */ 315 ret = i2c_add_adapter(&i2c_dev->adap); 316 317 amd_mp2_pm_runtime_put(mp2_dev); 318 319 if (ret < 0) 320 dev_err(&pdev->dev, "i2c add adapter failed = %d\n", ret); 321 322 return ret; 323 } 324 325 static void i2c_amd_remove(struct platform_device *pdev) 326 { 327 struct amd_i2c_dev *i2c_dev = platform_get_drvdata(pdev); 328 struct amd_i2c_common *i2c_common = &i2c_dev->common; 329 330 i2c_lock_bus(&i2c_dev->adap, I2C_LOCK_ROOT_ADAPTER); 331 332 i2c_amd_enable_set(i2c_dev, false); 333 amd_mp2_unregister_cb(i2c_common); 334 i2c_common->mp2_dev = NULL; 335 336 i2c_unlock_bus(&i2c_dev->adap, I2C_LOCK_ROOT_ADAPTER); 337 338 i2c_del_adapter(&i2c_dev->adap); 339 } 340 341 static const struct acpi_device_id i2c_amd_acpi_match[] = { 342 { "AMDI0011" }, 343 { } 344 }; 345 MODULE_DEVICE_TABLE(acpi, i2c_amd_acpi_match); 346 347 static struct platform_driver i2c_amd_plat_driver = { 348 .probe = i2c_amd_probe, 349 .remove_new = i2c_amd_remove, 350 .driver = { 351 .name = "i2c_amd_mp2", 352 .acpi_match_table = ACPI_PTR(i2c_amd_acpi_match), 353 }, 354 }; 355 module_platform_driver(i2c_amd_plat_driver); 356 357 MODULE_DESCRIPTION("AMD(R) MP2 I2C Platform Driver"); 358 MODULE_AUTHOR("Nehal Shah <nehal-bakulchandra.shah@amd.com>"); 359 MODULE_AUTHOR("Elie Morisse <syniurge@gmail.com>"); 360 MODULE_LICENSE("Dual BSD/GPL"); 361