1 /* 2 * Synopsys DesignWare I2C adapter driver. 3 * 4 * Based on the TI DAVINCI I2C adapter driver. 5 * 6 * Copyright (C) 2006 Texas Instruments. 7 * Copyright (C) 2007 MontaVista Software Inc. 8 * Copyright (C) 2009 Provigent Ltd. 9 * 10 * ---------------------------------------------------------------------------- 11 * 12 * This program is free software; you can redistribute it and/or modify 13 * it under the terms of the GNU General Public License as published by 14 * the Free Software Foundation; either version 2 of the License, or 15 * (at your option) any later version. 16 * 17 * This program is distributed in the hope that it will be useful, 18 * but WITHOUT ANY WARRANTY; without even the implied warranty of 19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 20 * GNU General Public License for more details. 21 * ---------------------------------------------------------------------------- 22 * 23 */ 24 #include <linux/acpi.h> 25 #include <linux/clk-provider.h> 26 #include <linux/clk.h> 27 #include <linux/delay.h> 28 #include <linux/dmi.h> 29 #include <linux/err.h> 30 #include <linux/errno.h> 31 #include <linux/i2c.h> 32 #include <linux/interrupt.h> 33 #include <linux/io.h> 34 #include <linux/kernel.h> 35 #include <linux/module.h> 36 #include <linux/of.h> 37 #include <linux/platform_data/i2c-designware.h> 38 #include <linux/platform_device.h> 39 #include <linux/pm.h> 40 #include <linux/pm_runtime.h> 41 #include <linux/property.h> 42 #include <linux/reset.h> 43 #include <linux/sched.h> 44 #include <linux/slab.h> 45 46 #include "i2c-designware-core.h" 47 48 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev) 49 { 50 return clk_get_rate(dev->clk)/1000; 51 } 52 53 #ifdef CONFIG_ACPI 54 /* 55 * The HCNT/LCNT information coming from ACPI should be the most accurate 56 * for given platform. However, some systems get it wrong. On such systems 57 * we get better results by calculating those based on the input clock. 58 */ 59 static const struct dmi_system_id dw_i2c_no_acpi_params[] = { 60 { 61 .ident = "Dell Inspiron 7348", 62 .matches = { 63 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 64 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"), 65 }, 66 }, 67 { } 68 }; 69 70 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[], 71 u16 *hcnt, u16 *lcnt, u32 *sda_hold) 72 { 73 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER }; 74 acpi_handle handle = ACPI_HANDLE(&pdev->dev); 75 union acpi_object *obj; 76 77 if (dmi_check_system(dw_i2c_no_acpi_params)) 78 return; 79 80 if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf))) 81 return; 82 83 obj = (union acpi_object *)buf.pointer; 84 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) { 85 const union acpi_object *objs = obj->package.elements; 86 87 *hcnt = (u16)objs[0].integer.value; 88 *lcnt = (u16)objs[1].integer.value; 89 *sda_hold = (u32)objs[2].integer.value; 90 } 91 92 kfree(buf.pointer); 93 } 94 95 static int dw_i2c_acpi_configure(struct platform_device *pdev) 96 { 97 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 98 u32 ss_ht = 0, fp_ht = 0, hs_ht = 0, fs_ht = 0; 99 acpi_handle handle = ACPI_HANDLE(&pdev->dev); 100 const struct acpi_device_id *id; 101 struct acpi_device *adev; 102 const char *uid; 103 104 dev->adapter.nr = -1; 105 dev->tx_fifo_depth = 32; 106 dev->rx_fifo_depth = 32; 107 108 /* 109 * Try to get SDA hold time and *CNT values from an ACPI method for 110 * selected speed modes. 111 */ 112 dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, &ss_ht); 113 dw_i2c_acpi_params(pdev, "FPCN", &dev->fp_hcnt, &dev->fp_lcnt, &fp_ht); 114 dw_i2c_acpi_params(pdev, "HSCN", &dev->hs_hcnt, &dev->hs_lcnt, &hs_ht); 115 dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, &fs_ht); 116 117 switch (dev->clk_freq) { 118 case 100000: 119 dev->sda_hold_time = ss_ht; 120 break; 121 case 1000000: 122 dev->sda_hold_time = fp_ht; 123 break; 124 case 3400000: 125 dev->sda_hold_time = hs_ht; 126 break; 127 case 400000: 128 default: 129 dev->sda_hold_time = fs_ht; 130 break; 131 } 132 133 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev); 134 if (id && id->driver_data) 135 dev->flags |= (u32)id->driver_data; 136 137 if (acpi_bus_get_device(handle, &adev)) 138 return -ENODEV; 139 140 /* 141 * Cherrytrail I2C7 gets used for the PMIC which gets accessed 142 * through ACPI opregions during late suspend / early resume 143 * disable pm for it. 144 */ 145 uid = adev->pnp.unique_id; 146 if ((dev->flags & MODEL_CHERRYTRAIL) && !strcmp(uid, "7")) 147 dev->pm_disabled = true; 148 149 return 0; 150 } 151 152 static const struct acpi_device_id dw_i2c_acpi_match[] = { 153 { "INT33C2", 0 }, 154 { "INT33C3", 0 }, 155 { "INT3432", 0 }, 156 { "INT3433", 0 }, 157 { "80860F41", 0 }, 158 { "808622C1", MODEL_CHERRYTRAIL }, 159 { "AMD0010", ACCESS_INTR_MASK }, 160 { "AMDI0010", ACCESS_INTR_MASK }, 161 { "AMDI0510", 0 }, 162 { "APMC0D0F", 0 }, 163 { "HISI02A1", 0 }, 164 { "HISI02A2", 0 }, 165 { } 166 }; 167 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match); 168 #else 169 static inline int dw_i2c_acpi_configure(struct platform_device *pdev) 170 { 171 return -ENODEV; 172 } 173 #endif 174 175 static void i2c_dw_configure_master(struct dw_i2c_dev *dev) 176 { 177 dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY; 178 179 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 180 DW_IC_CON_RESTART_EN; 181 182 dev->mode = DW_IC_MASTER; 183 184 switch (dev->clk_freq) { 185 case 100000: 186 dev->master_cfg |= DW_IC_CON_SPEED_STD; 187 break; 188 case 3400000: 189 dev->master_cfg |= DW_IC_CON_SPEED_HIGH; 190 break; 191 default: 192 dev->master_cfg |= DW_IC_CON_SPEED_FAST; 193 } 194 } 195 196 static void i2c_dw_configure_slave(struct dw_i2c_dev *dev) 197 { 198 dev->functionality = I2C_FUNC_SLAVE | DW_IC_DEFAULT_FUNCTIONALITY; 199 200 dev->slave_cfg = DW_IC_CON_RX_FIFO_FULL_HLD_CTRL | 201 DW_IC_CON_RESTART_EN | DW_IC_CON_STOP_DET_IFADDRESSED; 202 203 dev->mode = DW_IC_SLAVE; 204 205 switch (dev->clk_freq) { 206 case 100000: 207 dev->slave_cfg |= DW_IC_CON_SPEED_STD; 208 break; 209 case 3400000: 210 dev->slave_cfg |= DW_IC_CON_SPEED_HIGH; 211 break; 212 default: 213 dev->slave_cfg |= DW_IC_CON_SPEED_FAST; 214 } 215 } 216 217 static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare) 218 { 219 if (IS_ERR(i_dev->clk)) 220 return PTR_ERR(i_dev->clk); 221 222 if (prepare) 223 return clk_prepare_enable(i_dev->clk); 224 225 clk_disable_unprepare(i_dev->clk); 226 return 0; 227 } 228 229 static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id) 230 { 231 u32 param, tx_fifo_depth, rx_fifo_depth; 232 233 /* 234 * Try to detect the FIFO depth if not set by interface driver, 235 * the depth could be from 2 to 256 from HW spec. 236 */ 237 param = i2c_dw_read_comp_param(dev); 238 tx_fifo_depth = ((param >> 16) & 0xff) + 1; 239 rx_fifo_depth = ((param >> 8) & 0xff) + 1; 240 if (!dev->tx_fifo_depth) { 241 dev->tx_fifo_depth = tx_fifo_depth; 242 dev->rx_fifo_depth = rx_fifo_depth; 243 dev->adapter.nr = id; 244 } else if (tx_fifo_depth >= 2) { 245 dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth, 246 tx_fifo_depth); 247 dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth, 248 rx_fifo_depth); 249 } 250 } 251 252 static void dw_i2c_plat_pm_cleanup(struct dw_i2c_dev *dev) 253 { 254 pm_runtime_disable(dev->dev); 255 256 if (dev->pm_disabled) 257 pm_runtime_put_noidle(dev->dev); 258 } 259 260 static int dw_i2c_plat_probe(struct platform_device *pdev) 261 { 262 struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev); 263 struct i2c_adapter *adap; 264 struct dw_i2c_dev *dev; 265 u32 acpi_speed, ht = 0; 266 struct resource *mem; 267 int i, irq, ret; 268 static const int supported_speeds[] = { 269 0, 100000, 400000, 1000000, 3400000 270 }; 271 272 irq = platform_get_irq(pdev, 0); 273 if (irq < 0) 274 return irq; 275 276 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL); 277 if (!dev) 278 return -ENOMEM; 279 280 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 281 dev->base = devm_ioremap_resource(&pdev->dev, mem); 282 if (IS_ERR(dev->base)) 283 return PTR_ERR(dev->base); 284 285 dev->dev = &pdev->dev; 286 dev->irq = irq; 287 platform_set_drvdata(pdev, dev); 288 289 dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL); 290 if (IS_ERR(dev->rst)) { 291 if (PTR_ERR(dev->rst) == -EPROBE_DEFER) 292 return -EPROBE_DEFER; 293 } else { 294 reset_control_deassert(dev->rst); 295 } 296 297 if (pdata) { 298 dev->clk_freq = pdata->i2c_scl_freq; 299 } else { 300 device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns", 301 &ht); 302 device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns", 303 &dev->sda_falling_time); 304 device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns", 305 &dev->scl_falling_time); 306 device_property_read_u32(&pdev->dev, "clock-frequency", 307 &dev->clk_freq); 308 } 309 310 acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev); 311 /* 312 * Some DSTDs use a non standard speed, round down to the lowest 313 * standard speed. 314 */ 315 for (i = 1; i < ARRAY_SIZE(supported_speeds); i++) { 316 if (acpi_speed < supported_speeds[i]) 317 break; 318 } 319 acpi_speed = supported_speeds[i - 1]; 320 321 /* 322 * Find bus speed from the "clock-frequency" device property, ACPI 323 * or by using fast mode if neither is set. 324 */ 325 if (acpi_speed && dev->clk_freq) 326 dev->clk_freq = min(dev->clk_freq, acpi_speed); 327 else if (acpi_speed || dev->clk_freq) 328 dev->clk_freq = max(dev->clk_freq, acpi_speed); 329 else 330 dev->clk_freq = 400000; 331 332 if (has_acpi_companion(&pdev->dev)) 333 dw_i2c_acpi_configure(pdev); 334 335 /* 336 * Only standard mode at 100kHz, fast mode at 400kHz, 337 * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported. 338 */ 339 if (dev->clk_freq != 100000 && dev->clk_freq != 400000 340 && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) { 341 dev_err(&pdev->dev, 342 "%d Hz is unsupported, only 100kHz, 400kHz, 1MHz and 3.4MHz are supported\n", 343 dev->clk_freq); 344 ret = -EINVAL; 345 goto exit_reset; 346 } 347 348 ret = i2c_dw_probe_lock_support(dev); 349 if (ret) 350 goto exit_reset; 351 352 if (i2c_detect_slave_mode(&pdev->dev)) 353 i2c_dw_configure_slave(dev); 354 else 355 i2c_dw_configure_master(dev); 356 357 dev->clk = devm_clk_get(&pdev->dev, NULL); 358 if (!i2c_dw_plat_prepare_clk(dev, true)) { 359 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz; 360 361 if (!dev->sda_hold_time && ht) 362 dev->sda_hold_time = div_u64( 363 (u64)dev->get_clk_rate_khz(dev) * ht + 500000, 364 1000000); 365 } 366 367 dw_i2c_set_fifo_size(dev, pdev->id); 368 369 adap = &dev->adapter; 370 adap->owner = THIS_MODULE; 371 adap->class = I2C_CLASS_DEPRECATED; 372 ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev)); 373 adap->dev.of_node = pdev->dev.of_node; 374 375 /* The code below assumes runtime PM to be disabled. */ 376 WARN_ON(pm_runtime_enabled(&pdev->dev)); 377 378 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000); 379 pm_runtime_use_autosuspend(&pdev->dev); 380 pm_runtime_set_active(&pdev->dev); 381 382 if (dev->pm_disabled) 383 pm_runtime_get_noresume(&pdev->dev); 384 385 pm_runtime_enable(&pdev->dev); 386 387 if (dev->mode == DW_IC_SLAVE) 388 ret = i2c_dw_probe_slave(dev); 389 else 390 ret = i2c_dw_probe(dev); 391 392 if (ret) 393 goto exit_probe; 394 395 return ret; 396 397 exit_probe: 398 dw_i2c_plat_pm_cleanup(dev); 399 exit_reset: 400 if (!IS_ERR_OR_NULL(dev->rst)) 401 reset_control_assert(dev->rst); 402 return ret; 403 } 404 405 static int dw_i2c_plat_remove(struct platform_device *pdev) 406 { 407 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 408 409 pm_runtime_get_sync(&pdev->dev); 410 411 i2c_del_adapter(&dev->adapter); 412 413 dev->disable(dev); 414 415 pm_runtime_dont_use_autosuspend(&pdev->dev); 416 pm_runtime_put_sync(&pdev->dev); 417 dw_i2c_plat_pm_cleanup(dev); 418 419 if (!IS_ERR_OR_NULL(dev->rst)) 420 reset_control_assert(dev->rst); 421 422 i2c_dw_remove_lock_support(dev); 423 424 return 0; 425 } 426 427 #ifdef CONFIG_OF 428 static const struct of_device_id dw_i2c_of_match[] = { 429 { .compatible = "snps,designware-i2c", }, 430 {}, 431 }; 432 MODULE_DEVICE_TABLE(of, dw_i2c_of_match); 433 #endif 434 435 #ifdef CONFIG_PM_SLEEP 436 static int dw_i2c_plat_prepare(struct device *dev) 437 { 438 return pm_runtime_suspended(dev); 439 } 440 441 static void dw_i2c_plat_complete(struct device *dev) 442 { 443 if (dev->power.direct_complete) 444 pm_request_resume(dev); 445 } 446 #else 447 #define dw_i2c_plat_prepare NULL 448 #define dw_i2c_plat_complete NULL 449 #endif 450 451 #ifdef CONFIG_PM 452 static int dw_i2c_plat_suspend(struct device *dev) 453 { 454 struct dw_i2c_dev *i_dev = dev_get_drvdata(dev); 455 456 if (i_dev->suspended) { 457 i_dev->skip_resume = true; 458 return 0; 459 } 460 461 i_dev->disable(i_dev); 462 i2c_dw_plat_prepare_clk(i_dev, false); 463 464 i_dev->suspended = true; 465 466 return 0; 467 } 468 469 static int dw_i2c_plat_resume(struct device *dev) 470 { 471 struct dw_i2c_dev *i_dev = dev_get_drvdata(dev); 472 473 if (!i_dev->suspended) 474 return 0; 475 476 if (i_dev->skip_resume) { 477 i_dev->skip_resume = false; 478 return 0; 479 } 480 481 i2c_dw_plat_prepare_clk(i_dev, true); 482 i_dev->init(i_dev); 483 484 i_dev->suspended = false; 485 486 return 0; 487 } 488 489 static const struct dev_pm_ops dw_i2c_dev_pm_ops = { 490 .prepare = dw_i2c_plat_prepare, 491 .complete = dw_i2c_plat_complete, 492 SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume) 493 SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL) 494 }; 495 496 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops) 497 #else 498 #define DW_I2C_DEV_PMOPS NULL 499 #endif 500 501 /* Work with hotplug and coldplug */ 502 MODULE_ALIAS("platform:i2c_designware"); 503 504 static struct platform_driver dw_i2c_driver = { 505 .probe = dw_i2c_plat_probe, 506 .remove = dw_i2c_plat_remove, 507 .driver = { 508 .name = "i2c_designware", 509 .of_match_table = of_match_ptr(dw_i2c_of_match), 510 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match), 511 .pm = DW_I2C_DEV_PMOPS, 512 }, 513 }; 514 515 static int __init dw_i2c_init_driver(void) 516 { 517 return platform_driver_register(&dw_i2c_driver); 518 } 519 subsys_initcall(dw_i2c_init_driver); 520 521 static void __exit dw_i2c_exit_driver(void) 522 { 523 platform_driver_unregister(&dw_i2c_driver); 524 } 525 module_exit(dw_i2c_exit_driver); 526 527 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); 528 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter"); 529 MODULE_LICENSE("GPL"); 530