1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Synopsys DesignWare I2C adapter driver. 4 * 5 * Based on the TI DAVINCI I2C adapter driver. 6 * 7 * Copyright (C) 2006 Texas Instruments. 8 * Copyright (C) 2007 MontaVista Software Inc. 9 * Copyright (C) 2009 Provigent Ltd. 10 */ 11 #include <linux/acpi.h> 12 #include <linux/clk-provider.h> 13 #include <linux/clk.h> 14 #include <linux/delay.h> 15 #include <linux/dmi.h> 16 #include <linux/err.h> 17 #include <linux/errno.h> 18 #include <linux/i2c.h> 19 #include <linux/interrupt.h> 20 #include <linux/io.h> 21 #include <linux/kernel.h> 22 #include <linux/module.h> 23 #include <linux/of.h> 24 #include <linux/platform_data/i2c-designware.h> 25 #include <linux/platform_device.h> 26 #include <linux/pm.h> 27 #include <linux/pm_runtime.h> 28 #include <linux/property.h> 29 #include <linux/reset.h> 30 #include <linux/sched.h> 31 #include <linux/slab.h> 32 #include <linux/suspend.h> 33 34 #include "i2c-designware-core.h" 35 36 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev) 37 { 38 return clk_get_rate(dev->clk)/1000; 39 } 40 41 #ifdef CONFIG_ACPI 42 /* 43 * The HCNT/LCNT information coming from ACPI should be the most accurate 44 * for given platform. However, some systems get it wrong. On such systems 45 * we get better results by calculating those based on the input clock. 46 */ 47 static const struct dmi_system_id dw_i2c_no_acpi_params[] = { 48 { 49 .ident = "Dell Inspiron 7348", 50 .matches = { 51 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 52 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"), 53 }, 54 }, 55 { } 56 }; 57 58 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[], 59 u16 *hcnt, u16 *lcnt, u32 *sda_hold) 60 { 61 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER }; 62 acpi_handle handle = ACPI_HANDLE(&pdev->dev); 63 union acpi_object *obj; 64 65 if (dmi_check_system(dw_i2c_no_acpi_params)) 66 return; 67 68 if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf))) 69 return; 70 71 obj = (union acpi_object *)buf.pointer; 72 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) { 73 const union acpi_object *objs = obj->package.elements; 74 75 *hcnt = (u16)objs[0].integer.value; 76 *lcnt = (u16)objs[1].integer.value; 77 *sda_hold = (u32)objs[2].integer.value; 78 } 79 80 kfree(buf.pointer); 81 } 82 83 static int dw_i2c_acpi_configure(struct platform_device *pdev) 84 { 85 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 86 struct i2c_timings *t = &dev->timings; 87 u32 ss_ht = 0, fp_ht = 0, hs_ht = 0, fs_ht = 0; 88 acpi_handle handle = ACPI_HANDLE(&pdev->dev); 89 const struct acpi_device_id *id; 90 struct acpi_device *adev; 91 const char *uid; 92 93 dev->adapter.nr = -1; 94 dev->tx_fifo_depth = 32; 95 dev->rx_fifo_depth = 32; 96 97 /* 98 * Try to get SDA hold time and *CNT values from an ACPI method for 99 * selected speed modes. 100 */ 101 dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, &ss_ht); 102 dw_i2c_acpi_params(pdev, "FPCN", &dev->fp_hcnt, &dev->fp_lcnt, &fp_ht); 103 dw_i2c_acpi_params(pdev, "HSCN", &dev->hs_hcnt, &dev->hs_lcnt, &hs_ht); 104 dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, &fs_ht); 105 106 switch (t->bus_freq_hz) { 107 case 100000: 108 dev->sda_hold_time = ss_ht; 109 break; 110 case 1000000: 111 dev->sda_hold_time = fp_ht; 112 break; 113 case 3400000: 114 dev->sda_hold_time = hs_ht; 115 break; 116 case 400000: 117 default: 118 dev->sda_hold_time = fs_ht; 119 break; 120 } 121 122 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev); 123 if (id && id->driver_data) 124 dev->flags |= (u32)id->driver_data; 125 126 if (acpi_bus_get_device(handle, &adev)) 127 return -ENODEV; 128 129 /* 130 * Cherrytrail I2C7 gets used for the PMIC which gets accessed 131 * through ACPI opregions during late suspend / early resume 132 * disable pm for it. 133 */ 134 uid = adev->pnp.unique_id; 135 if ((dev->flags & MODEL_CHERRYTRAIL) && !strcmp(uid, "7")) 136 dev->pm_disabled = true; 137 138 return 0; 139 } 140 141 static const struct acpi_device_id dw_i2c_acpi_match[] = { 142 { "INT33C2", 0 }, 143 { "INT33C3", 0 }, 144 { "INT3432", 0 }, 145 { "INT3433", 0 }, 146 { "80860F41", 0 }, 147 { "808622C1", MODEL_CHERRYTRAIL }, 148 { "AMD0010", ACCESS_INTR_MASK }, 149 { "AMDI0010", ACCESS_INTR_MASK }, 150 { "AMDI0510", 0 }, 151 { "APMC0D0F", 0 }, 152 { "HISI02A1", 0 }, 153 { "HISI02A2", 0 }, 154 { } 155 }; 156 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match); 157 #else 158 static inline int dw_i2c_acpi_configure(struct platform_device *pdev) 159 { 160 return -ENODEV; 161 } 162 #endif 163 164 static void i2c_dw_configure_master(struct dw_i2c_dev *dev) 165 { 166 struct i2c_timings *t = &dev->timings; 167 168 dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY; 169 170 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 171 DW_IC_CON_RESTART_EN; 172 173 dev->mode = DW_IC_MASTER; 174 175 switch (t->bus_freq_hz) { 176 case 100000: 177 dev->master_cfg |= DW_IC_CON_SPEED_STD; 178 break; 179 case 3400000: 180 dev->master_cfg |= DW_IC_CON_SPEED_HIGH; 181 break; 182 default: 183 dev->master_cfg |= DW_IC_CON_SPEED_FAST; 184 } 185 } 186 187 static void i2c_dw_configure_slave(struct dw_i2c_dev *dev) 188 { 189 dev->functionality = I2C_FUNC_SLAVE | DW_IC_DEFAULT_FUNCTIONALITY; 190 191 dev->slave_cfg = DW_IC_CON_RX_FIFO_FULL_HLD_CTRL | 192 DW_IC_CON_RESTART_EN | DW_IC_CON_STOP_DET_IFADDRESSED; 193 194 dev->mode = DW_IC_SLAVE; 195 } 196 197 static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id) 198 { 199 u32 param, tx_fifo_depth, rx_fifo_depth; 200 201 /* 202 * Try to detect the FIFO depth if not set by interface driver, 203 * the depth could be from 2 to 256 from HW spec. 204 */ 205 param = i2c_dw_read_comp_param(dev); 206 tx_fifo_depth = ((param >> 16) & 0xff) + 1; 207 rx_fifo_depth = ((param >> 8) & 0xff) + 1; 208 if (!dev->tx_fifo_depth) { 209 dev->tx_fifo_depth = tx_fifo_depth; 210 dev->rx_fifo_depth = rx_fifo_depth; 211 dev->adapter.nr = id; 212 } else if (tx_fifo_depth >= 2) { 213 dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth, 214 tx_fifo_depth); 215 dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth, 216 rx_fifo_depth); 217 } 218 } 219 220 static void dw_i2c_plat_pm_cleanup(struct dw_i2c_dev *dev) 221 { 222 pm_runtime_disable(dev->dev); 223 224 if (dev->pm_disabled) 225 pm_runtime_put_noidle(dev->dev); 226 } 227 228 static int dw_i2c_plat_probe(struct platform_device *pdev) 229 { 230 struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev); 231 struct i2c_adapter *adap; 232 struct dw_i2c_dev *dev; 233 struct i2c_timings *t; 234 u32 acpi_speed; 235 struct resource *mem; 236 int i, irq, ret; 237 static const int supported_speeds[] = { 238 0, 100000, 400000, 1000000, 3400000 239 }; 240 241 irq = platform_get_irq(pdev, 0); 242 if (irq < 0) 243 return irq; 244 245 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL); 246 if (!dev) 247 return -ENOMEM; 248 249 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 250 dev->base = devm_ioremap_resource(&pdev->dev, mem); 251 if (IS_ERR(dev->base)) 252 return PTR_ERR(dev->base); 253 254 dev->dev = &pdev->dev; 255 dev->irq = irq; 256 platform_set_drvdata(pdev, dev); 257 258 dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL); 259 if (IS_ERR(dev->rst)) { 260 if (PTR_ERR(dev->rst) == -EPROBE_DEFER) 261 return -EPROBE_DEFER; 262 } else { 263 reset_control_deassert(dev->rst); 264 } 265 266 t = &dev->timings; 267 if (pdata) 268 t->bus_freq_hz = pdata->i2c_scl_freq; 269 else 270 i2c_parse_fw_timings(&pdev->dev, t, false); 271 272 acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev); 273 /* 274 * Some DSTDs use a non standard speed, round down to the lowest 275 * standard speed. 276 */ 277 for (i = 1; i < ARRAY_SIZE(supported_speeds); i++) { 278 if (acpi_speed < supported_speeds[i]) 279 break; 280 } 281 acpi_speed = supported_speeds[i - 1]; 282 283 /* 284 * Find bus speed from the "clock-frequency" device property, ACPI 285 * or by using fast mode if neither is set. 286 */ 287 if (acpi_speed && t->bus_freq_hz) 288 t->bus_freq_hz = min(t->bus_freq_hz, acpi_speed); 289 else if (acpi_speed || t->bus_freq_hz) 290 t->bus_freq_hz = max(t->bus_freq_hz, acpi_speed); 291 else 292 t->bus_freq_hz = 400000; 293 294 if (has_acpi_companion(&pdev->dev)) 295 dw_i2c_acpi_configure(pdev); 296 297 /* 298 * Only standard mode at 100kHz, fast mode at 400kHz, 299 * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported. 300 */ 301 if (t->bus_freq_hz != 100000 && t->bus_freq_hz != 400000 && 302 t->bus_freq_hz != 1000000 && t->bus_freq_hz != 3400000) { 303 dev_err(&pdev->dev, 304 "%d Hz is unsupported, only 100kHz, 400kHz, 1MHz and 3.4MHz are supported\n", 305 t->bus_freq_hz); 306 ret = -EINVAL; 307 goto exit_reset; 308 } 309 310 ret = i2c_dw_probe_lock_support(dev); 311 if (ret) 312 goto exit_reset; 313 314 if (i2c_detect_slave_mode(&pdev->dev)) 315 i2c_dw_configure_slave(dev); 316 else 317 i2c_dw_configure_master(dev); 318 319 dev->clk = devm_clk_get(&pdev->dev, NULL); 320 if (!i2c_dw_prepare_clk(dev, true)) { 321 u64 clk_khz; 322 323 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz; 324 clk_khz = dev->get_clk_rate_khz(dev); 325 326 if (!dev->sda_hold_time && t->sda_hold_ns) 327 dev->sda_hold_time = 328 div_u64(clk_khz * t->sda_hold_ns + 500000, 1000000); 329 } 330 331 dw_i2c_set_fifo_size(dev, pdev->id); 332 333 adap = &dev->adapter; 334 adap->owner = THIS_MODULE; 335 adap->class = I2C_CLASS_DEPRECATED; 336 ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev)); 337 adap->dev.of_node = pdev->dev.of_node; 338 339 dev_pm_set_driver_flags(&pdev->dev, 340 DPM_FLAG_SMART_PREPARE | 341 DPM_FLAG_SMART_SUSPEND | 342 DPM_FLAG_LEAVE_SUSPENDED); 343 344 /* The code below assumes runtime PM to be disabled. */ 345 WARN_ON(pm_runtime_enabled(&pdev->dev)); 346 347 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000); 348 pm_runtime_use_autosuspend(&pdev->dev); 349 pm_runtime_set_active(&pdev->dev); 350 351 if (dev->pm_disabled) 352 pm_runtime_get_noresume(&pdev->dev); 353 354 pm_runtime_enable(&pdev->dev); 355 356 if (dev->mode == DW_IC_SLAVE) 357 ret = i2c_dw_probe_slave(dev); 358 else 359 ret = i2c_dw_probe(dev); 360 361 if (ret) 362 goto exit_probe; 363 364 return ret; 365 366 exit_probe: 367 dw_i2c_plat_pm_cleanup(dev); 368 exit_reset: 369 if (!IS_ERR_OR_NULL(dev->rst)) 370 reset_control_assert(dev->rst); 371 return ret; 372 } 373 374 static int dw_i2c_plat_remove(struct platform_device *pdev) 375 { 376 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 377 378 pm_runtime_get_sync(&pdev->dev); 379 380 i2c_del_adapter(&dev->adapter); 381 382 dev->disable(dev); 383 384 pm_runtime_dont_use_autosuspend(&pdev->dev); 385 pm_runtime_put_sync(&pdev->dev); 386 dw_i2c_plat_pm_cleanup(dev); 387 388 if (!IS_ERR_OR_NULL(dev->rst)) 389 reset_control_assert(dev->rst); 390 391 i2c_dw_remove_lock_support(dev); 392 393 return 0; 394 } 395 396 #ifdef CONFIG_OF 397 static const struct of_device_id dw_i2c_of_match[] = { 398 { .compatible = "snps,designware-i2c", }, 399 {}, 400 }; 401 MODULE_DEVICE_TABLE(of, dw_i2c_of_match); 402 #endif 403 404 #ifdef CONFIG_PM_SLEEP 405 static int dw_i2c_plat_prepare(struct device *dev) 406 { 407 /* 408 * If the ACPI companion device object is present for this device, it 409 * may be accessed during suspend and resume of other devices via I2C 410 * operation regions, so tell the PM core and middle layers to avoid 411 * skipping system suspend/resume callbacks for it in that case. 412 */ 413 return !has_acpi_companion(dev); 414 } 415 416 static void dw_i2c_plat_complete(struct device *dev) 417 { 418 /* 419 * The device can only be in runtime suspend at this point if it has not 420 * been resumed throughout the ending system suspend/resume cycle, so if 421 * the platform firmware might mess up with it, request the runtime PM 422 * framework to resume it. 423 */ 424 if (pm_runtime_suspended(dev) && pm_resume_via_firmware()) 425 pm_request_resume(dev); 426 } 427 #else 428 #define dw_i2c_plat_prepare NULL 429 #define dw_i2c_plat_complete NULL 430 #endif 431 432 #ifdef CONFIG_PM 433 static int dw_i2c_plat_suspend(struct device *dev) 434 { 435 struct dw_i2c_dev *i_dev = dev_get_drvdata(dev); 436 437 if (i_dev->pm_disabled) 438 return 0; 439 440 i_dev->disable(i_dev); 441 i2c_dw_prepare_clk(i_dev, false); 442 443 return 0; 444 } 445 446 static int dw_i2c_plat_resume(struct device *dev) 447 { 448 struct dw_i2c_dev *i_dev = dev_get_drvdata(dev); 449 450 if (!i_dev->pm_disabled) 451 i2c_dw_prepare_clk(i_dev, true); 452 453 i_dev->init(i_dev); 454 455 return 0; 456 } 457 458 static const struct dev_pm_ops dw_i2c_dev_pm_ops = { 459 .prepare = dw_i2c_plat_prepare, 460 .complete = dw_i2c_plat_complete, 461 SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume) 462 SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL) 463 }; 464 465 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops) 466 #else 467 #define DW_I2C_DEV_PMOPS NULL 468 #endif 469 470 /* Work with hotplug and coldplug */ 471 MODULE_ALIAS("platform:i2c_designware"); 472 473 static struct platform_driver dw_i2c_driver = { 474 .probe = dw_i2c_plat_probe, 475 .remove = dw_i2c_plat_remove, 476 .driver = { 477 .name = "i2c_designware", 478 .of_match_table = of_match_ptr(dw_i2c_of_match), 479 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match), 480 .pm = DW_I2C_DEV_PMOPS, 481 }, 482 }; 483 484 static int __init dw_i2c_init_driver(void) 485 { 486 return platform_driver_register(&dw_i2c_driver); 487 } 488 subsys_initcall(dw_i2c_init_driver); 489 490 static void __exit dw_i2c_exit_driver(void) 491 { 492 platform_driver_unregister(&dw_i2c_driver); 493 } 494 module_exit(dw_i2c_exit_driver); 495 496 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); 497 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter"); 498 MODULE_LICENSE("GPL"); 499