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 89 dev->tx_fifo_depth = 32; 90 dev->rx_fifo_depth = 32; 91 92 /* 93 * Try to get SDA hold time and *CNT values from an ACPI method for 94 * selected speed modes. 95 */ 96 dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, &ss_ht); 97 dw_i2c_acpi_params(pdev, "FPCN", &dev->fp_hcnt, &dev->fp_lcnt, &fp_ht); 98 dw_i2c_acpi_params(pdev, "HSCN", &dev->hs_hcnt, &dev->hs_lcnt, &hs_ht); 99 dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, &fs_ht); 100 101 switch (t->bus_freq_hz) { 102 case 100000: 103 dev->sda_hold_time = ss_ht; 104 break; 105 case 1000000: 106 dev->sda_hold_time = fp_ht; 107 break; 108 case 3400000: 109 dev->sda_hold_time = hs_ht; 110 break; 111 case 400000: 112 default: 113 dev->sda_hold_time = fs_ht; 114 break; 115 } 116 117 return 0; 118 } 119 120 static const struct acpi_device_id dw_i2c_acpi_match[] = { 121 { "INT33C2", 0 }, 122 { "INT33C3", 0 }, 123 { "INT3432", 0 }, 124 { "INT3433", 0 }, 125 { "80860F41", ACCESS_NO_IRQ_SUSPEND }, 126 { "808622C1", ACCESS_NO_IRQ_SUSPEND | MODEL_CHERRYTRAIL }, 127 { "AMD0010", ACCESS_INTR_MASK }, 128 { "AMDI0010", ACCESS_INTR_MASK }, 129 { "AMDI0510", 0 }, 130 { "APMC0D0F", 0 }, 131 { "HISI02A1", 0 }, 132 { "HISI02A2", 0 }, 133 { } 134 }; 135 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match); 136 #else 137 static inline int dw_i2c_acpi_configure(struct platform_device *pdev) 138 { 139 return -ENODEV; 140 } 141 #endif 142 143 #ifdef CONFIG_OF 144 #define MSCC_ICPU_CFG_TWI_DELAY 0x0 145 #define MSCC_ICPU_CFG_TWI_DELAY_ENABLE BIT(0) 146 #define MSCC_ICPU_CFG_TWI_SPIKE_FILTER 0x4 147 148 static int mscc_twi_set_sda_hold_time(struct dw_i2c_dev *dev) 149 { 150 writel((dev->sda_hold_time << 1) | MSCC_ICPU_CFG_TWI_DELAY_ENABLE, 151 dev->ext + MSCC_ICPU_CFG_TWI_DELAY); 152 153 return 0; 154 } 155 156 static int dw_i2c_of_configure(struct platform_device *pdev) 157 { 158 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 159 struct resource *mem; 160 161 switch (dev->flags & MODEL_MASK) { 162 case MODEL_MSCC_OCELOT: 163 mem = platform_get_resource(pdev, IORESOURCE_MEM, 1); 164 dev->ext = devm_ioremap_resource(&pdev->dev, mem); 165 if (!IS_ERR(dev->ext)) 166 dev->set_sda_hold_time = mscc_twi_set_sda_hold_time; 167 break; 168 default: 169 break; 170 } 171 172 return 0; 173 } 174 175 static const struct of_device_id dw_i2c_of_match[] = { 176 { .compatible = "snps,designware-i2c", }, 177 { .compatible = "mscc,ocelot-i2c", .data = (void *)MODEL_MSCC_OCELOT }, 178 {}, 179 }; 180 MODULE_DEVICE_TABLE(of, dw_i2c_of_match); 181 #else 182 static inline int dw_i2c_of_configure(struct platform_device *pdev) 183 { 184 return -ENODEV; 185 } 186 #endif 187 188 static void i2c_dw_configure_master(struct dw_i2c_dev *dev) 189 { 190 struct i2c_timings *t = &dev->timings; 191 192 dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY; 193 194 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 195 DW_IC_CON_RESTART_EN; 196 197 dev->mode = DW_IC_MASTER; 198 199 switch (t->bus_freq_hz) { 200 case 100000: 201 dev->master_cfg |= DW_IC_CON_SPEED_STD; 202 break; 203 case 3400000: 204 dev->master_cfg |= DW_IC_CON_SPEED_HIGH; 205 break; 206 default: 207 dev->master_cfg |= DW_IC_CON_SPEED_FAST; 208 } 209 } 210 211 static void i2c_dw_configure_slave(struct dw_i2c_dev *dev) 212 { 213 dev->functionality = I2C_FUNC_SLAVE | DW_IC_DEFAULT_FUNCTIONALITY; 214 215 dev->slave_cfg = DW_IC_CON_RX_FIFO_FULL_HLD_CTRL | 216 DW_IC_CON_RESTART_EN | DW_IC_CON_STOP_DET_IFADDRESSED; 217 218 dev->mode = DW_IC_SLAVE; 219 } 220 221 static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev) 222 { 223 u32 param, tx_fifo_depth, rx_fifo_depth; 224 225 /* 226 * Try to detect the FIFO depth if not set by interface driver, 227 * the depth could be from 2 to 256 from HW spec. 228 */ 229 param = i2c_dw_read_comp_param(dev); 230 tx_fifo_depth = ((param >> 16) & 0xff) + 1; 231 rx_fifo_depth = ((param >> 8) & 0xff) + 1; 232 if (!dev->tx_fifo_depth) { 233 dev->tx_fifo_depth = tx_fifo_depth; 234 dev->rx_fifo_depth = rx_fifo_depth; 235 } else if (tx_fifo_depth >= 2) { 236 dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth, 237 tx_fifo_depth); 238 dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth, 239 rx_fifo_depth); 240 } 241 } 242 243 static void dw_i2c_plat_pm_cleanup(struct dw_i2c_dev *dev) 244 { 245 pm_runtime_disable(dev->dev); 246 247 if (dev->shared_with_punit) 248 pm_runtime_put_noidle(dev->dev); 249 } 250 251 static int dw_i2c_plat_probe(struct platform_device *pdev) 252 { 253 struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev); 254 struct i2c_adapter *adap; 255 struct dw_i2c_dev *dev; 256 struct i2c_timings *t; 257 u32 acpi_speed; 258 struct resource *mem; 259 int i, irq, ret; 260 static const int supported_speeds[] = { 261 0, 100000, 400000, 1000000, 3400000 262 }; 263 264 irq = platform_get_irq(pdev, 0); 265 if (irq < 0) 266 return irq; 267 268 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL); 269 if (!dev) 270 return -ENOMEM; 271 272 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 273 dev->base = devm_ioremap_resource(&pdev->dev, mem); 274 if (IS_ERR(dev->base)) 275 return PTR_ERR(dev->base); 276 277 dev->dev = &pdev->dev; 278 dev->irq = irq; 279 platform_set_drvdata(pdev, dev); 280 281 dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL); 282 if (IS_ERR(dev->rst)) 283 return PTR_ERR(dev->rst); 284 285 reset_control_deassert(dev->rst); 286 287 t = &dev->timings; 288 if (pdata) 289 t->bus_freq_hz = pdata->i2c_scl_freq; 290 else 291 i2c_parse_fw_timings(&pdev->dev, t, false); 292 293 acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev); 294 /* 295 * Some DSTDs use a non standard speed, round down to the lowest 296 * standard speed. 297 */ 298 for (i = 1; i < ARRAY_SIZE(supported_speeds); i++) { 299 if (acpi_speed < supported_speeds[i]) 300 break; 301 } 302 acpi_speed = supported_speeds[i - 1]; 303 304 /* 305 * Find bus speed from the "clock-frequency" device property, ACPI 306 * or by using fast mode if neither is set. 307 */ 308 if (acpi_speed && t->bus_freq_hz) 309 t->bus_freq_hz = min(t->bus_freq_hz, acpi_speed); 310 else if (acpi_speed || t->bus_freq_hz) 311 t->bus_freq_hz = max(t->bus_freq_hz, acpi_speed); 312 else 313 t->bus_freq_hz = 400000; 314 315 dev->flags |= (uintptr_t)device_get_match_data(&pdev->dev); 316 317 if (pdev->dev.of_node) 318 dw_i2c_of_configure(pdev); 319 320 if (has_acpi_companion(&pdev->dev)) 321 dw_i2c_acpi_configure(pdev); 322 323 /* 324 * Only standard mode at 100kHz, fast mode at 400kHz, 325 * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported. 326 */ 327 if (t->bus_freq_hz != 100000 && t->bus_freq_hz != 400000 && 328 t->bus_freq_hz != 1000000 && t->bus_freq_hz != 3400000) { 329 dev_err(&pdev->dev, 330 "%d Hz is unsupported, only 100kHz, 400kHz, 1MHz and 3.4MHz are supported\n", 331 t->bus_freq_hz); 332 ret = -EINVAL; 333 goto exit_reset; 334 } 335 336 ret = i2c_dw_probe_lock_support(dev); 337 if (ret) 338 goto exit_reset; 339 340 if (i2c_detect_slave_mode(&pdev->dev)) 341 i2c_dw_configure_slave(dev); 342 else 343 i2c_dw_configure_master(dev); 344 345 /* Optional interface clock */ 346 dev->pclk = devm_clk_get_optional(&pdev->dev, "pclk"); 347 if (IS_ERR(dev->pclk)) { 348 ret = PTR_ERR(dev->pclk); 349 goto exit_reset; 350 } 351 352 dev->clk = devm_clk_get(&pdev->dev, NULL); 353 if (!i2c_dw_prepare_clk(dev, true)) { 354 u64 clk_khz; 355 356 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz; 357 clk_khz = dev->get_clk_rate_khz(dev); 358 359 if (!dev->sda_hold_time && t->sda_hold_ns) 360 dev->sda_hold_time = 361 div_u64(clk_khz * t->sda_hold_ns + 500000, 1000000); 362 } 363 364 dw_i2c_set_fifo_size(dev); 365 366 adap = &dev->adapter; 367 adap->owner = THIS_MODULE; 368 adap->class = I2C_CLASS_DEPRECATED; 369 ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev)); 370 adap->dev.of_node = pdev->dev.of_node; 371 adap->nr = -1; 372 373 dev_pm_set_driver_flags(&pdev->dev, 374 DPM_FLAG_SMART_PREPARE | 375 DPM_FLAG_SMART_SUSPEND | 376 DPM_FLAG_LEAVE_SUSPENDED); 377 378 /* The code below assumes runtime PM to be disabled. */ 379 WARN_ON(pm_runtime_enabled(&pdev->dev)); 380 381 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000); 382 pm_runtime_use_autosuspend(&pdev->dev); 383 pm_runtime_set_active(&pdev->dev); 384 385 if (dev->shared_with_punit) 386 pm_runtime_get_noresume(&pdev->dev); 387 388 pm_runtime_enable(&pdev->dev); 389 390 if (dev->mode == DW_IC_SLAVE) 391 ret = i2c_dw_probe_slave(dev); 392 else 393 ret = i2c_dw_probe(dev); 394 395 if (ret) 396 goto exit_probe; 397 398 return ret; 399 400 exit_probe: 401 dw_i2c_plat_pm_cleanup(dev); 402 exit_reset: 403 reset_control_assert(dev->rst); 404 return ret; 405 } 406 407 static int dw_i2c_plat_remove(struct platform_device *pdev) 408 { 409 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 410 411 pm_runtime_get_sync(&pdev->dev); 412 413 i2c_del_adapter(&dev->adapter); 414 415 dev->disable(dev); 416 417 pm_runtime_dont_use_autosuspend(&pdev->dev); 418 pm_runtime_put_sync(&pdev->dev); 419 dw_i2c_plat_pm_cleanup(dev); 420 421 reset_control_assert(dev->rst); 422 423 return 0; 424 } 425 426 #ifdef CONFIG_PM_SLEEP 427 static int dw_i2c_plat_prepare(struct device *dev) 428 { 429 /* 430 * If the ACPI companion device object is present for this device, it 431 * may be accessed during suspend and resume of other devices via I2C 432 * operation regions, so tell the PM core and middle layers to avoid 433 * skipping system suspend/resume callbacks for it in that case. 434 */ 435 return !has_acpi_companion(dev); 436 } 437 438 static void dw_i2c_plat_complete(struct device *dev) 439 { 440 /* 441 * The device can only be in runtime suspend at this point if it has not 442 * been resumed throughout the ending system suspend/resume cycle, so if 443 * the platform firmware might mess up with it, request the runtime PM 444 * framework to resume it. 445 */ 446 if (pm_runtime_suspended(dev) && pm_resume_via_firmware()) 447 pm_request_resume(dev); 448 } 449 #else 450 #define dw_i2c_plat_prepare NULL 451 #define dw_i2c_plat_complete NULL 452 #endif 453 454 #ifdef CONFIG_PM 455 static int dw_i2c_plat_suspend(struct device *dev) 456 { 457 struct dw_i2c_dev *i_dev = dev_get_drvdata(dev); 458 459 i_dev->suspended = true; 460 461 if (i_dev->shared_with_punit) 462 return 0; 463 464 i_dev->disable(i_dev); 465 i2c_dw_prepare_clk(i_dev, false); 466 467 return 0; 468 } 469 470 static int dw_i2c_plat_resume(struct device *dev) 471 { 472 struct dw_i2c_dev *i_dev = dev_get_drvdata(dev); 473 474 if (!i_dev->shared_with_punit) 475 i2c_dw_prepare_clk(i_dev, true); 476 477 i_dev->init(i_dev); 478 i_dev->suspended = false; 479 480 return 0; 481 } 482 483 static const struct dev_pm_ops dw_i2c_dev_pm_ops = { 484 .prepare = dw_i2c_plat_prepare, 485 .complete = dw_i2c_plat_complete, 486 SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume) 487 SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL) 488 }; 489 490 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops) 491 #else 492 #define DW_I2C_DEV_PMOPS NULL 493 #endif 494 495 /* Work with hotplug and coldplug */ 496 MODULE_ALIAS("platform:i2c_designware"); 497 498 static struct platform_driver dw_i2c_driver = { 499 .probe = dw_i2c_plat_probe, 500 .remove = dw_i2c_plat_remove, 501 .driver = { 502 .name = "i2c_designware", 503 .of_match_table = of_match_ptr(dw_i2c_of_match), 504 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match), 505 .pm = DW_I2C_DEV_PMOPS, 506 }, 507 }; 508 509 static int __init dw_i2c_init_driver(void) 510 { 511 return platform_driver_register(&dw_i2c_driver); 512 } 513 subsys_initcall(dw_i2c_init_driver); 514 515 static void __exit dw_i2c_exit_driver(void) 516 { 517 platform_driver_unregister(&dw_i2c_driver); 518 } 519 module_exit(dw_i2c_exit_driver); 520 521 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); 522 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter"); 523 MODULE_LICENSE("GPL"); 524