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 I2C_MAX_STANDARD_MODE_FREQ: 103 dev->sda_hold_time = ss_ht; 104 break; 105 case I2C_MAX_FAST_MODE_PLUS_FREQ: 106 dev->sda_hold_time = fp_ht; 107 break; 108 case I2C_MAX_HIGH_SPEED_MODE_FREQ: 109 dev->sda_hold_time = hs_ht; 110 break; 111 case I2C_MAX_FAST_MODE_FREQ: 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 { "HISI02A3", 0 }, 134 { } 135 }; 136 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match); 137 #else 138 static inline int dw_i2c_acpi_configure(struct platform_device *pdev) 139 { 140 return -ENODEV; 141 } 142 #endif 143 144 #ifdef CONFIG_OF 145 #define MSCC_ICPU_CFG_TWI_DELAY 0x0 146 #define MSCC_ICPU_CFG_TWI_DELAY_ENABLE BIT(0) 147 #define MSCC_ICPU_CFG_TWI_SPIKE_FILTER 0x4 148 149 static int mscc_twi_set_sda_hold_time(struct dw_i2c_dev *dev) 150 { 151 writel((dev->sda_hold_time << 1) | MSCC_ICPU_CFG_TWI_DELAY_ENABLE, 152 dev->ext + MSCC_ICPU_CFG_TWI_DELAY); 153 154 return 0; 155 } 156 157 static int dw_i2c_of_configure(struct platform_device *pdev) 158 { 159 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 160 struct resource *mem; 161 162 switch (dev->flags & MODEL_MASK) { 163 case MODEL_MSCC_OCELOT: 164 mem = platform_get_resource(pdev, IORESOURCE_MEM, 1); 165 dev->ext = devm_ioremap_resource(&pdev->dev, mem); 166 if (!IS_ERR(dev->ext)) 167 dev->set_sda_hold_time = mscc_twi_set_sda_hold_time; 168 break; 169 default: 170 break; 171 } 172 173 return 0; 174 } 175 176 static const struct of_device_id dw_i2c_of_match[] = { 177 { .compatible = "snps,designware-i2c", }, 178 { .compatible = "mscc,ocelot-i2c", .data = (void *)MODEL_MSCC_OCELOT }, 179 {}, 180 }; 181 MODULE_DEVICE_TABLE(of, dw_i2c_of_match); 182 #else 183 static inline int dw_i2c_of_configure(struct platform_device *pdev) 184 { 185 return -ENODEV; 186 } 187 #endif 188 189 static void i2c_dw_configure_master(struct dw_i2c_dev *dev) 190 { 191 struct i2c_timings *t = &dev->timings; 192 193 dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY; 194 195 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 196 DW_IC_CON_RESTART_EN; 197 198 dev->mode = DW_IC_MASTER; 199 200 switch (t->bus_freq_hz) { 201 case I2C_MAX_STANDARD_MODE_FREQ: 202 dev->master_cfg |= DW_IC_CON_SPEED_STD; 203 break; 204 case I2C_MAX_HIGH_SPEED_MODE_FREQ: 205 dev->master_cfg |= DW_IC_CON_SPEED_HIGH; 206 break; 207 default: 208 dev->master_cfg |= DW_IC_CON_SPEED_FAST; 209 } 210 } 211 212 static void i2c_dw_configure_slave(struct dw_i2c_dev *dev) 213 { 214 dev->functionality = I2C_FUNC_SLAVE | DW_IC_DEFAULT_FUNCTIONALITY; 215 216 dev->slave_cfg = DW_IC_CON_RX_FIFO_FULL_HLD_CTRL | 217 DW_IC_CON_RESTART_EN | DW_IC_CON_STOP_DET_IFADDRESSED; 218 219 dev->mode = DW_IC_SLAVE; 220 } 221 222 static void dw_i2c_plat_pm_cleanup(struct dw_i2c_dev *dev) 223 { 224 pm_runtime_disable(dev->dev); 225 226 if (dev->shared_with_punit) 227 pm_runtime_put_noidle(dev->dev); 228 } 229 230 static const u32 supported_speeds[] = { 231 I2C_MAX_HIGH_SPEED_MODE_FREQ, 232 I2C_MAX_FAST_MODE_PLUS_FREQ, 233 I2C_MAX_FAST_MODE_FREQ, 234 I2C_MAX_STANDARD_MODE_FREQ, 235 }; 236 237 static int dw_i2c_plat_probe(struct platform_device *pdev) 238 { 239 struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev); 240 struct i2c_adapter *adap; 241 struct dw_i2c_dev *dev; 242 struct i2c_timings *t; 243 u32 acpi_speed; 244 struct resource *mem; 245 int i, irq, ret; 246 247 irq = platform_get_irq(pdev, 0); 248 if (irq < 0) 249 return irq; 250 251 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL); 252 if (!dev) 253 return -ENOMEM; 254 255 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 256 dev->base = devm_ioremap_resource(&pdev->dev, mem); 257 if (IS_ERR(dev->base)) 258 return PTR_ERR(dev->base); 259 260 dev->dev = &pdev->dev; 261 dev->irq = irq; 262 platform_set_drvdata(pdev, dev); 263 264 dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL); 265 if (IS_ERR(dev->rst)) 266 return PTR_ERR(dev->rst); 267 268 reset_control_deassert(dev->rst); 269 270 t = &dev->timings; 271 if (pdata) 272 t->bus_freq_hz = pdata->i2c_scl_freq; 273 else 274 i2c_parse_fw_timings(&pdev->dev, t, false); 275 276 acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev); 277 /* 278 * Some DSTDs use a non standard speed, round down to the lowest 279 * standard speed. 280 */ 281 for (i = 0; i < ARRAY_SIZE(supported_speeds); i++) { 282 if (acpi_speed >= supported_speeds[i]) 283 break; 284 } 285 acpi_speed = i < ARRAY_SIZE(supported_speeds) ? supported_speeds[i] : 0; 286 287 /* 288 * Find bus speed from the "clock-frequency" device property, ACPI 289 * or by using fast mode if neither is set. 290 */ 291 if (acpi_speed && t->bus_freq_hz) 292 t->bus_freq_hz = min(t->bus_freq_hz, acpi_speed); 293 else if (acpi_speed || t->bus_freq_hz) 294 t->bus_freq_hz = max(t->bus_freq_hz, acpi_speed); 295 else 296 t->bus_freq_hz = I2C_MAX_FAST_MODE_FREQ; 297 298 dev->flags |= (uintptr_t)device_get_match_data(&pdev->dev); 299 300 if (pdev->dev.of_node) 301 dw_i2c_of_configure(pdev); 302 303 if (has_acpi_companion(&pdev->dev)) 304 dw_i2c_acpi_configure(pdev); 305 306 /* 307 * Only standard mode at 100kHz, fast mode at 400kHz, 308 * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported. 309 */ 310 for (i = 0; i < ARRAY_SIZE(supported_speeds); i++) { 311 if (t->bus_freq_hz == supported_speeds[i]) 312 break; 313 } 314 if (i == ARRAY_SIZE(supported_speeds)) { 315 dev_err(&pdev->dev, 316 "%d Hz is unsupported, only 100kHz, 400kHz, 1MHz and 3.4MHz are supported\n", 317 t->bus_freq_hz); 318 ret = -EINVAL; 319 goto exit_reset; 320 } 321 322 ret = i2c_dw_probe_lock_support(dev); 323 if (ret) 324 goto exit_reset; 325 326 if (i2c_detect_slave_mode(&pdev->dev)) 327 i2c_dw_configure_slave(dev); 328 else 329 i2c_dw_configure_master(dev); 330 331 /* Optional interface clock */ 332 dev->pclk = devm_clk_get_optional(&pdev->dev, "pclk"); 333 if (IS_ERR(dev->pclk)) { 334 ret = PTR_ERR(dev->pclk); 335 goto exit_reset; 336 } 337 338 dev->clk = devm_clk_get(&pdev->dev, NULL); 339 if (!i2c_dw_prepare_clk(dev, true)) { 340 u64 clk_khz; 341 342 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz; 343 clk_khz = dev->get_clk_rate_khz(dev); 344 345 if (!dev->sda_hold_time && t->sda_hold_ns) 346 dev->sda_hold_time = 347 div_u64(clk_khz * t->sda_hold_ns + 500000, 1000000); 348 } 349 350 adap = &dev->adapter; 351 adap->owner = THIS_MODULE; 352 adap->class = I2C_CLASS_DEPRECATED; 353 ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev)); 354 adap->dev.of_node = pdev->dev.of_node; 355 adap->nr = -1; 356 357 dev_pm_set_driver_flags(&pdev->dev, 358 DPM_FLAG_SMART_PREPARE | 359 DPM_FLAG_SMART_SUSPEND | 360 DPM_FLAG_LEAVE_SUSPENDED); 361 362 /* The code below assumes runtime PM to be disabled. */ 363 WARN_ON(pm_runtime_enabled(&pdev->dev)); 364 365 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000); 366 pm_runtime_use_autosuspend(&pdev->dev); 367 pm_runtime_set_active(&pdev->dev); 368 369 if (dev->shared_with_punit) 370 pm_runtime_get_noresume(&pdev->dev); 371 372 pm_runtime_enable(&pdev->dev); 373 374 if (dev->mode == DW_IC_SLAVE) 375 ret = i2c_dw_probe_slave(dev); 376 else 377 ret = i2c_dw_probe(dev); 378 379 if (ret) 380 goto exit_probe; 381 382 return ret; 383 384 exit_probe: 385 dw_i2c_plat_pm_cleanup(dev); 386 exit_reset: 387 reset_control_assert(dev->rst); 388 return ret; 389 } 390 391 static int dw_i2c_plat_remove(struct platform_device *pdev) 392 { 393 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 394 395 pm_runtime_get_sync(&pdev->dev); 396 397 i2c_del_adapter(&dev->adapter); 398 399 dev->disable(dev); 400 401 pm_runtime_dont_use_autosuspend(&pdev->dev); 402 pm_runtime_put_sync(&pdev->dev); 403 dw_i2c_plat_pm_cleanup(dev); 404 405 reset_control_assert(dev->rst); 406 407 return 0; 408 } 409 410 #ifdef CONFIG_PM_SLEEP 411 static int dw_i2c_plat_prepare(struct device *dev) 412 { 413 /* 414 * If the ACPI companion device object is present for this device, it 415 * may be accessed during suspend and resume of other devices via I2C 416 * operation regions, so tell the PM core and middle layers to avoid 417 * skipping system suspend/resume callbacks for it in that case. 418 */ 419 return !has_acpi_companion(dev); 420 } 421 422 static void dw_i2c_plat_complete(struct device *dev) 423 { 424 /* 425 * The device can only be in runtime suspend at this point if it has not 426 * been resumed throughout the ending system suspend/resume cycle, so if 427 * the platform firmware might mess up with it, request the runtime PM 428 * framework to resume it. 429 */ 430 if (pm_runtime_suspended(dev) && pm_resume_via_firmware()) 431 pm_request_resume(dev); 432 } 433 #else 434 #define dw_i2c_plat_prepare NULL 435 #define dw_i2c_plat_complete NULL 436 #endif 437 438 #ifdef CONFIG_PM 439 static int dw_i2c_plat_suspend(struct device *dev) 440 { 441 struct dw_i2c_dev *i_dev = dev_get_drvdata(dev); 442 443 i_dev->suspended = true; 444 445 if (i_dev->shared_with_punit) 446 return 0; 447 448 i_dev->disable(i_dev); 449 i2c_dw_prepare_clk(i_dev, false); 450 451 return 0; 452 } 453 454 static int dw_i2c_plat_resume(struct device *dev) 455 { 456 struct dw_i2c_dev *i_dev = dev_get_drvdata(dev); 457 458 if (!i_dev->shared_with_punit) 459 i2c_dw_prepare_clk(i_dev, true); 460 461 i_dev->init(i_dev); 462 i_dev->suspended = false; 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