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 #include <linux/suspend.h> 46 47 #include "i2c-designware-core.h" 48 49 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev) 50 { 51 return clk_get_rate(dev->clk)/1000; 52 } 53 54 #ifdef CONFIG_ACPI 55 /* 56 * The HCNT/LCNT information coming from ACPI should be the most accurate 57 * for given platform. However, some systems get it wrong. On such systems 58 * we get better results by calculating those based on the input clock. 59 */ 60 static const struct dmi_system_id dw_i2c_no_acpi_params[] = { 61 { 62 .ident = "Dell Inspiron 7348", 63 .matches = { 64 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 65 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"), 66 }, 67 }, 68 { } 69 }; 70 71 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[], 72 u16 *hcnt, u16 *lcnt, u32 *sda_hold) 73 { 74 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER }; 75 acpi_handle handle = ACPI_HANDLE(&pdev->dev); 76 union acpi_object *obj; 77 78 if (dmi_check_system(dw_i2c_no_acpi_params)) 79 return; 80 81 if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf))) 82 return; 83 84 obj = (union acpi_object *)buf.pointer; 85 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) { 86 const union acpi_object *objs = obj->package.elements; 87 88 *hcnt = (u16)objs[0].integer.value; 89 *lcnt = (u16)objs[1].integer.value; 90 *sda_hold = (u32)objs[2].integer.value; 91 } 92 93 kfree(buf.pointer); 94 } 95 96 static int dw_i2c_acpi_configure(struct platform_device *pdev) 97 { 98 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 99 u32 ss_ht = 0, fp_ht = 0, hs_ht = 0, fs_ht = 0; 100 acpi_handle handle = ACPI_HANDLE(&pdev->dev); 101 const struct acpi_device_id *id; 102 struct acpi_device *adev; 103 const char *uid; 104 105 dev->adapter.nr = -1; 106 dev->tx_fifo_depth = 32; 107 dev->rx_fifo_depth = 32; 108 109 /* 110 * Try to get SDA hold time and *CNT values from an ACPI method for 111 * selected speed modes. 112 */ 113 dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, &ss_ht); 114 dw_i2c_acpi_params(pdev, "FPCN", &dev->fp_hcnt, &dev->fp_lcnt, &fp_ht); 115 dw_i2c_acpi_params(pdev, "HSCN", &dev->hs_hcnt, &dev->hs_lcnt, &hs_ht); 116 dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, &fs_ht); 117 118 switch (dev->clk_freq) { 119 case 100000: 120 dev->sda_hold_time = ss_ht; 121 break; 122 case 1000000: 123 dev->sda_hold_time = fp_ht; 124 break; 125 case 3400000: 126 dev->sda_hold_time = hs_ht; 127 break; 128 case 400000: 129 default: 130 dev->sda_hold_time = fs_ht; 131 break; 132 } 133 134 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev); 135 if (id && id->driver_data) 136 dev->flags |= (u32)id->driver_data; 137 138 if (acpi_bus_get_device(handle, &adev)) 139 return -ENODEV; 140 141 /* 142 * Cherrytrail I2C7 gets used for the PMIC which gets accessed 143 * through ACPI opregions during late suspend / early resume 144 * disable pm for it. 145 */ 146 uid = adev->pnp.unique_id; 147 if ((dev->flags & MODEL_CHERRYTRAIL) && !strcmp(uid, "7")) 148 dev->pm_disabled = true; 149 150 return 0; 151 } 152 153 static const struct acpi_device_id dw_i2c_acpi_match[] = { 154 { "INT33C2", 0 }, 155 { "INT33C3", 0 }, 156 { "INT3432", 0 }, 157 { "INT3433", 0 }, 158 { "80860F41", 0 }, 159 { "808622C1", MODEL_CHERRYTRAIL }, 160 { "AMD0010", ACCESS_INTR_MASK }, 161 { "AMDI0010", ACCESS_INTR_MASK }, 162 { "AMDI0510", 0 }, 163 { "APMC0D0F", 0 }, 164 { "HISI02A1", 0 }, 165 { "HISI02A2", 0 }, 166 { } 167 }; 168 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match); 169 #else 170 static inline int dw_i2c_acpi_configure(struct platform_device *pdev) 171 { 172 return -ENODEV; 173 } 174 #endif 175 176 static void i2c_dw_configure_master(struct dw_i2c_dev *dev) 177 { 178 dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY; 179 180 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 181 DW_IC_CON_RESTART_EN; 182 183 dev->mode = DW_IC_MASTER; 184 185 switch (dev->clk_freq) { 186 case 100000: 187 dev->master_cfg |= DW_IC_CON_SPEED_STD; 188 break; 189 case 3400000: 190 dev->master_cfg |= DW_IC_CON_SPEED_HIGH; 191 break; 192 default: 193 dev->master_cfg |= DW_IC_CON_SPEED_FAST; 194 } 195 } 196 197 static void i2c_dw_configure_slave(struct dw_i2c_dev *dev) 198 { 199 dev->functionality = I2C_FUNC_SLAVE | DW_IC_DEFAULT_FUNCTIONALITY; 200 201 dev->slave_cfg = DW_IC_CON_RX_FIFO_FULL_HLD_CTRL | 202 DW_IC_CON_RESTART_EN | DW_IC_CON_STOP_DET_IFADDRESSED; 203 204 dev->mode = DW_IC_SLAVE; 205 } 206 207 static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id) 208 { 209 u32 param, tx_fifo_depth, rx_fifo_depth; 210 211 /* 212 * Try to detect the FIFO depth if not set by interface driver, 213 * the depth could be from 2 to 256 from HW spec. 214 */ 215 param = i2c_dw_read_comp_param(dev); 216 tx_fifo_depth = ((param >> 16) & 0xff) + 1; 217 rx_fifo_depth = ((param >> 8) & 0xff) + 1; 218 if (!dev->tx_fifo_depth) { 219 dev->tx_fifo_depth = tx_fifo_depth; 220 dev->rx_fifo_depth = rx_fifo_depth; 221 dev->adapter.nr = id; 222 } else if (tx_fifo_depth >= 2) { 223 dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth, 224 tx_fifo_depth); 225 dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth, 226 rx_fifo_depth); 227 } 228 } 229 230 static void dw_i2c_plat_pm_cleanup(struct dw_i2c_dev *dev) 231 { 232 pm_runtime_disable(dev->dev); 233 234 if (dev->pm_disabled) 235 pm_runtime_put_noidle(dev->dev); 236 } 237 238 static int dw_i2c_plat_probe(struct platform_device *pdev) 239 { 240 struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev); 241 struct i2c_adapter *adap; 242 struct dw_i2c_dev *dev; 243 u32 acpi_speed, ht = 0; 244 struct resource *mem; 245 int i, irq, ret; 246 static const int supported_speeds[] = { 247 0, 100000, 400000, 1000000, 3400000 248 }; 249 250 irq = platform_get_irq(pdev, 0); 251 if (irq < 0) 252 return irq; 253 254 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL); 255 if (!dev) 256 return -ENOMEM; 257 258 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 259 dev->base = devm_ioremap_resource(&pdev->dev, mem); 260 if (IS_ERR(dev->base)) 261 return PTR_ERR(dev->base); 262 263 dev->dev = &pdev->dev; 264 dev->irq = irq; 265 platform_set_drvdata(pdev, dev); 266 267 dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL); 268 if (IS_ERR(dev->rst)) { 269 if (PTR_ERR(dev->rst) == -EPROBE_DEFER) 270 return -EPROBE_DEFER; 271 } else { 272 reset_control_deassert(dev->rst); 273 } 274 275 if (pdata) { 276 dev->clk_freq = pdata->i2c_scl_freq; 277 } else { 278 device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns", 279 &ht); 280 device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns", 281 &dev->sda_falling_time); 282 device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns", 283 &dev->scl_falling_time); 284 device_property_read_u32(&pdev->dev, "clock-frequency", 285 &dev->clk_freq); 286 } 287 288 acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev); 289 /* 290 * Some DSTDs use a non standard speed, round down to the lowest 291 * standard speed. 292 */ 293 for (i = 1; i < ARRAY_SIZE(supported_speeds); i++) { 294 if (acpi_speed < supported_speeds[i]) 295 break; 296 } 297 acpi_speed = supported_speeds[i - 1]; 298 299 /* 300 * Find bus speed from the "clock-frequency" device property, ACPI 301 * or by using fast mode if neither is set. 302 */ 303 if (acpi_speed && dev->clk_freq) 304 dev->clk_freq = min(dev->clk_freq, acpi_speed); 305 else if (acpi_speed || dev->clk_freq) 306 dev->clk_freq = max(dev->clk_freq, acpi_speed); 307 else 308 dev->clk_freq = 400000; 309 310 if (has_acpi_companion(&pdev->dev)) 311 dw_i2c_acpi_configure(pdev); 312 313 /* 314 * Only standard mode at 100kHz, fast mode at 400kHz, 315 * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported. 316 */ 317 if (dev->clk_freq != 100000 && dev->clk_freq != 400000 318 && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) { 319 dev_err(&pdev->dev, 320 "%d Hz is unsupported, only 100kHz, 400kHz, 1MHz and 3.4MHz are supported\n", 321 dev->clk_freq); 322 ret = -EINVAL; 323 goto exit_reset; 324 } 325 326 ret = i2c_dw_probe_lock_support(dev); 327 if (ret) 328 goto exit_reset; 329 330 if (i2c_detect_slave_mode(&pdev->dev)) 331 i2c_dw_configure_slave(dev); 332 else 333 i2c_dw_configure_master(dev); 334 335 dev->clk = devm_clk_get(&pdev->dev, NULL); 336 if (!i2c_dw_prepare_clk(dev, true)) { 337 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz; 338 339 if (!dev->sda_hold_time && ht) 340 dev->sda_hold_time = div_u64( 341 (u64)dev->get_clk_rate_khz(dev) * ht + 500000, 342 1000000); 343 } 344 345 dw_i2c_set_fifo_size(dev, pdev->id); 346 347 adap = &dev->adapter; 348 adap->owner = THIS_MODULE; 349 adap->class = I2C_CLASS_DEPRECATED; 350 ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev)); 351 adap->dev.of_node = pdev->dev.of_node; 352 353 dev_pm_set_driver_flags(&pdev->dev, 354 DPM_FLAG_SMART_PREPARE | 355 DPM_FLAG_SMART_SUSPEND | 356 DPM_FLAG_LEAVE_SUSPENDED); 357 358 /* The code below assumes runtime PM to be disabled. */ 359 WARN_ON(pm_runtime_enabled(&pdev->dev)); 360 361 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000); 362 pm_runtime_use_autosuspend(&pdev->dev); 363 pm_runtime_set_active(&pdev->dev); 364 365 if (dev->pm_disabled) 366 pm_runtime_get_noresume(&pdev->dev); 367 368 pm_runtime_enable(&pdev->dev); 369 370 if (dev->mode == DW_IC_SLAVE) 371 ret = i2c_dw_probe_slave(dev); 372 else 373 ret = i2c_dw_probe(dev); 374 375 if (ret) 376 goto exit_probe; 377 378 return ret; 379 380 exit_probe: 381 dw_i2c_plat_pm_cleanup(dev); 382 exit_reset: 383 if (!IS_ERR_OR_NULL(dev->rst)) 384 reset_control_assert(dev->rst); 385 return ret; 386 } 387 388 static int dw_i2c_plat_remove(struct platform_device *pdev) 389 { 390 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 391 392 pm_runtime_get_sync(&pdev->dev); 393 394 i2c_del_adapter(&dev->adapter); 395 396 dev->disable(dev); 397 398 pm_runtime_dont_use_autosuspend(&pdev->dev); 399 pm_runtime_put_sync(&pdev->dev); 400 dw_i2c_plat_pm_cleanup(dev); 401 402 if (!IS_ERR_OR_NULL(dev->rst)) 403 reset_control_assert(dev->rst); 404 405 i2c_dw_remove_lock_support(dev); 406 407 return 0; 408 } 409 410 #ifdef CONFIG_OF 411 static const struct of_device_id dw_i2c_of_match[] = { 412 { .compatible = "snps,designware-i2c", }, 413 {}, 414 }; 415 MODULE_DEVICE_TABLE(of, dw_i2c_of_match); 416 #endif 417 418 #ifdef CONFIG_PM_SLEEP 419 static int dw_i2c_plat_prepare(struct device *dev) 420 { 421 /* 422 * If the ACPI companion device object is present for this device, it 423 * may be accessed during suspend and resume of other devices via I2C 424 * operation regions, so tell the PM core and middle layers to avoid 425 * skipping system suspend/resume callbacks for it in that case. 426 */ 427 return !has_acpi_companion(dev); 428 } 429 430 static void dw_i2c_plat_complete(struct device *dev) 431 { 432 /* 433 * The device can only be in runtime suspend at this point if it has not 434 * been resumed throughout the ending system suspend/resume cycle, so if 435 * the platform firmware might mess up with it, request the runtime PM 436 * framework to resume it. 437 */ 438 if (pm_runtime_suspended(dev) && pm_resume_via_firmware()) 439 pm_request_resume(dev); 440 } 441 #else 442 #define dw_i2c_plat_prepare NULL 443 #define dw_i2c_plat_complete NULL 444 #endif 445 446 #ifdef CONFIG_PM 447 static int dw_i2c_plat_suspend(struct device *dev) 448 { 449 struct dw_i2c_dev *i_dev = dev_get_drvdata(dev); 450 451 i_dev->disable(i_dev); 452 i2c_dw_prepare_clk(i_dev, false); 453 454 return 0; 455 } 456 457 static int dw_i2c_plat_resume(struct device *dev) 458 { 459 struct dw_i2c_dev *i_dev = dev_get_drvdata(dev); 460 461 i2c_dw_prepare_clk(i_dev, true); 462 i_dev->init(i_dev); 463 464 return 0; 465 } 466 467 static const struct dev_pm_ops dw_i2c_dev_pm_ops = { 468 .prepare = dw_i2c_plat_prepare, 469 .complete = dw_i2c_plat_complete, 470 SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume) 471 SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL) 472 }; 473 474 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops) 475 #else 476 #define DW_I2C_DEV_PMOPS NULL 477 #endif 478 479 /* Work with hotplug and coldplug */ 480 MODULE_ALIAS("platform:i2c_designware"); 481 482 static struct platform_driver dw_i2c_driver = { 483 .probe = dw_i2c_plat_probe, 484 .remove = dw_i2c_plat_remove, 485 .driver = { 486 .name = "i2c_designware", 487 .of_match_table = of_match_ptr(dw_i2c_of_match), 488 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match), 489 .pm = DW_I2C_DEV_PMOPS, 490 }, 491 }; 492 493 static int __init dw_i2c_init_driver(void) 494 { 495 return platform_driver_register(&dw_i2c_driver); 496 } 497 subsys_initcall(dw_i2c_init_driver); 498 499 static void __exit dw_i2c_exit_driver(void) 500 { 501 platform_driver_unregister(&dw_i2c_driver); 502 } 503 module_exit(dw_i2c_exit_driver); 504 505 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); 506 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter"); 507 MODULE_LICENSE("GPL"); 508