1 /* 2 * Synopsys DesignWare I2C adapter driver (master only). 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/kernel.h> 25 #include <linux/module.h> 26 #include <linux/delay.h> 27 #include <linux/dmi.h> 28 #include <linux/i2c.h> 29 #include <linux/clk.h> 30 #include <linux/clk-provider.h> 31 #include <linux/errno.h> 32 #include <linux/sched.h> 33 #include <linux/err.h> 34 #include <linux/interrupt.h> 35 #include <linux/of.h> 36 #include <linux/platform_device.h> 37 #include <linux/pm.h> 38 #include <linux/pm_runtime.h> 39 #include <linux/property.h> 40 #include <linux/io.h> 41 #include <linux/reset.h> 42 #include <linux/slab.h> 43 #include <linux/acpi.h> 44 #include <linux/platform_data/i2c-designware.h> 45 #include "i2c-designware-core.h" 46 47 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev) 48 { 49 return clk_get_rate(dev->clk)/1000; 50 } 51 52 #ifdef CONFIG_ACPI 53 /* 54 * The HCNT/LCNT information coming from ACPI should be the most accurate 55 * for given platform. However, some systems get it wrong. On such systems 56 * we get better results by calculating those based on the input clock. 57 */ 58 static const struct dmi_system_id dw_i2c_no_acpi_params[] = { 59 { 60 .ident = "Dell Inspiron 7348", 61 .matches = { 62 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 63 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"), 64 }, 65 }, 66 { } 67 }; 68 69 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[], 70 u16 *hcnt, u16 *lcnt, u32 *sda_hold) 71 { 72 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER }; 73 acpi_handle handle = ACPI_HANDLE(&pdev->dev); 74 union acpi_object *obj; 75 76 if (dmi_check_system(dw_i2c_no_acpi_params)) 77 return; 78 79 if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf))) 80 return; 81 82 obj = (union acpi_object *)buf.pointer; 83 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) { 84 const union acpi_object *objs = obj->package.elements; 85 86 *hcnt = (u16)objs[0].integer.value; 87 *lcnt = (u16)objs[1].integer.value; 88 *sda_hold = (u32)objs[2].integer.value; 89 } 90 91 kfree(buf.pointer); 92 } 93 94 static int dw_i2c_acpi_configure(struct platform_device *pdev) 95 { 96 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 97 u32 ss_ht = 0, fp_ht = 0, hs_ht = 0, fs_ht = 0; 98 acpi_handle handle = ACPI_HANDLE(&pdev->dev); 99 const struct acpi_device_id *id; 100 struct acpi_device *adev; 101 const char *uid; 102 103 dev->adapter.nr = -1; 104 dev->tx_fifo_depth = 32; 105 dev->rx_fifo_depth = 32; 106 107 /* 108 * Try to get SDA hold time and *CNT values from an ACPI method for 109 * selected speed modes. 110 */ 111 dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, &ss_ht); 112 dw_i2c_acpi_params(pdev, "FPCN", &dev->fp_hcnt, &dev->fp_lcnt, &fp_ht); 113 dw_i2c_acpi_params(pdev, "HSCN", &dev->hs_hcnt, &dev->hs_lcnt, &hs_ht); 114 dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, &fs_ht); 115 116 switch (dev->clk_freq) { 117 case 100000: 118 dev->sda_hold_time = ss_ht; 119 break; 120 case 1000000: 121 dev->sda_hold_time = fp_ht; 122 break; 123 case 3400000: 124 dev->sda_hold_time = hs_ht; 125 break; 126 case 400000: 127 default: 128 dev->sda_hold_time = fs_ht; 129 break; 130 } 131 132 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev); 133 if (id && id->driver_data) 134 dev->flags |= (u32)id->driver_data; 135 136 if (acpi_bus_get_device(handle, &adev)) 137 return -ENODEV; 138 139 /* 140 * Cherrytrail I2C7 gets used for the PMIC which gets accessed 141 * through ACPI opregions during late suspend / early resume 142 * disable pm for it. 143 */ 144 uid = adev->pnp.unique_id; 145 if ((dev->flags & MODEL_CHERRYTRAIL) && !strcmp(uid, "7")) 146 dev->pm_disabled = true; 147 148 return 0; 149 } 150 151 static const struct acpi_device_id dw_i2c_acpi_match[] = { 152 { "INT33C2", 0 }, 153 { "INT33C3", 0 }, 154 { "INT3432", 0 }, 155 { "INT3433", 0 }, 156 { "80860F41", 0 }, 157 { "808622C1", MODEL_CHERRYTRAIL }, 158 { "AMD0010", ACCESS_INTR_MASK }, 159 { "AMDI0010", ACCESS_INTR_MASK }, 160 { "AMDI0510", 0 }, 161 { "APMC0D0F", 0 }, 162 { "HISI02A1", 0 }, 163 { "HISI02A2", 0 }, 164 { } 165 }; 166 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match); 167 #else 168 static inline int dw_i2c_acpi_configure(struct platform_device *pdev) 169 { 170 return -ENODEV; 171 } 172 #endif 173 174 static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare) 175 { 176 if (IS_ERR(i_dev->clk)) 177 return PTR_ERR(i_dev->clk); 178 179 if (prepare) 180 return clk_prepare_enable(i_dev->clk); 181 182 clk_disable_unprepare(i_dev->clk); 183 return 0; 184 } 185 186 static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id) 187 { 188 u32 param, tx_fifo_depth, rx_fifo_depth; 189 190 /* 191 * Try to detect the FIFO depth if not set by interface driver, 192 * the depth could be from 2 to 256 from HW spec. 193 */ 194 param = i2c_dw_read_comp_param(dev); 195 tx_fifo_depth = ((param >> 16) & 0xff) + 1; 196 rx_fifo_depth = ((param >> 8) & 0xff) + 1; 197 if (!dev->tx_fifo_depth) { 198 dev->tx_fifo_depth = tx_fifo_depth; 199 dev->rx_fifo_depth = rx_fifo_depth; 200 dev->adapter.nr = id; 201 } else if (tx_fifo_depth >= 2) { 202 dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth, 203 tx_fifo_depth); 204 dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth, 205 rx_fifo_depth); 206 } 207 } 208 209 static int dw_i2c_plat_probe(struct platform_device *pdev) 210 { 211 struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev); 212 struct dw_i2c_dev *dev; 213 struct i2c_adapter *adap; 214 struct resource *mem; 215 int irq, r; 216 u32 acpi_speed, ht = 0; 217 218 irq = platform_get_irq(pdev, 0); 219 if (irq < 0) 220 return irq; 221 222 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL); 223 if (!dev) 224 return -ENOMEM; 225 226 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 227 dev->base = devm_ioremap_resource(&pdev->dev, mem); 228 if (IS_ERR(dev->base)) 229 return PTR_ERR(dev->base); 230 231 dev->dev = &pdev->dev; 232 dev->irq = irq; 233 platform_set_drvdata(pdev, dev); 234 235 dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL); 236 if (IS_ERR(dev->rst)) { 237 if (PTR_ERR(dev->rst) == -EPROBE_DEFER) 238 return -EPROBE_DEFER; 239 } else { 240 reset_control_deassert(dev->rst); 241 } 242 243 if (pdata) { 244 dev->clk_freq = pdata->i2c_scl_freq; 245 } else { 246 device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns", 247 &ht); 248 device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns", 249 &dev->sda_falling_time); 250 device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns", 251 &dev->scl_falling_time); 252 device_property_read_u32(&pdev->dev, "clock-frequency", 253 &dev->clk_freq); 254 } 255 256 acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev); 257 /* 258 * Find bus speed from the "clock-frequency" device property, ACPI 259 * or by using fast mode if neither is set. 260 */ 261 if (acpi_speed && dev->clk_freq) 262 dev->clk_freq = min(dev->clk_freq, acpi_speed); 263 else if (acpi_speed || dev->clk_freq) 264 dev->clk_freq = max(dev->clk_freq, acpi_speed); 265 else 266 dev->clk_freq = 400000; 267 268 if (has_acpi_companion(&pdev->dev)) 269 dw_i2c_acpi_configure(pdev); 270 271 /* 272 * Only standard mode at 100kHz, fast mode at 400kHz, 273 * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported. 274 */ 275 if (dev->clk_freq != 100000 && dev->clk_freq != 400000 276 && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) { 277 dev_err(&pdev->dev, 278 "Only 100kHz, 400kHz, 1MHz and 3.4MHz supported"); 279 r = -EINVAL; 280 goto exit_reset; 281 } 282 283 r = i2c_dw_probe_lock_support(dev); 284 if (r) 285 goto exit_reset; 286 287 dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY; 288 289 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 290 DW_IC_CON_RESTART_EN; 291 292 switch (dev->clk_freq) { 293 case 100000: 294 dev->master_cfg |= DW_IC_CON_SPEED_STD; 295 break; 296 case 3400000: 297 dev->master_cfg |= DW_IC_CON_SPEED_HIGH; 298 break; 299 default: 300 dev->master_cfg |= DW_IC_CON_SPEED_FAST; 301 } 302 303 dev->clk = devm_clk_get(&pdev->dev, NULL); 304 if (!i2c_dw_plat_prepare_clk(dev, true)) { 305 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz; 306 307 if (!dev->sda_hold_time && ht) 308 dev->sda_hold_time = div_u64( 309 (u64)dev->get_clk_rate_khz(dev) * ht + 500000, 310 1000000); 311 } 312 313 dw_i2c_set_fifo_size(dev, pdev->id); 314 315 adap = &dev->adapter; 316 adap->owner = THIS_MODULE; 317 adap->class = I2C_CLASS_DEPRECATED; 318 ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev)); 319 adap->dev.of_node = pdev->dev.of_node; 320 321 if (dev->pm_disabled) { 322 pm_runtime_forbid(&pdev->dev); 323 } else { 324 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000); 325 pm_runtime_use_autosuspend(&pdev->dev); 326 pm_runtime_set_active(&pdev->dev); 327 pm_runtime_enable(&pdev->dev); 328 } 329 330 r = i2c_dw_probe(dev); 331 if (r) 332 goto exit_probe; 333 334 return r; 335 336 exit_probe: 337 if (!dev->pm_disabled) 338 pm_runtime_disable(&pdev->dev); 339 exit_reset: 340 if (!IS_ERR_OR_NULL(dev->rst)) 341 reset_control_assert(dev->rst); 342 return r; 343 } 344 345 static int dw_i2c_plat_remove(struct platform_device *pdev) 346 { 347 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 348 349 pm_runtime_get_sync(&pdev->dev); 350 351 i2c_del_adapter(&dev->adapter); 352 353 i2c_dw_disable(dev); 354 355 pm_runtime_dont_use_autosuspend(&pdev->dev); 356 pm_runtime_put_sync(&pdev->dev); 357 if (!dev->pm_disabled) 358 pm_runtime_disable(&pdev->dev); 359 if (!IS_ERR_OR_NULL(dev->rst)) 360 reset_control_assert(dev->rst); 361 362 i2c_dw_remove_lock_support(dev); 363 364 return 0; 365 } 366 367 #ifdef CONFIG_OF 368 static const struct of_device_id dw_i2c_of_match[] = { 369 { .compatible = "snps,designware-i2c", }, 370 {}, 371 }; 372 MODULE_DEVICE_TABLE(of, dw_i2c_of_match); 373 #endif 374 375 #ifdef CONFIG_PM_SLEEP 376 static int dw_i2c_plat_prepare(struct device *dev) 377 { 378 return pm_runtime_suspended(dev); 379 } 380 381 static void dw_i2c_plat_complete(struct device *dev) 382 { 383 if (dev->power.direct_complete) 384 pm_request_resume(dev); 385 } 386 #else 387 #define dw_i2c_plat_prepare NULL 388 #define dw_i2c_plat_complete NULL 389 #endif 390 391 #ifdef CONFIG_PM 392 static int dw_i2c_plat_suspend(struct device *dev) 393 { 394 struct platform_device *pdev = to_platform_device(dev); 395 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 396 397 i2c_dw_disable(i_dev); 398 i2c_dw_plat_prepare_clk(i_dev, false); 399 400 return 0; 401 } 402 403 static int dw_i2c_plat_resume(struct device *dev) 404 { 405 struct platform_device *pdev = to_platform_device(dev); 406 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 407 408 i2c_dw_plat_prepare_clk(i_dev, true); 409 i2c_dw_init(i_dev); 410 411 return 0; 412 } 413 414 static const struct dev_pm_ops dw_i2c_dev_pm_ops = { 415 .prepare = dw_i2c_plat_prepare, 416 .complete = dw_i2c_plat_complete, 417 SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume) 418 SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL) 419 }; 420 421 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops) 422 #else 423 #define DW_I2C_DEV_PMOPS NULL 424 #endif 425 426 /* work with hotplug and coldplug */ 427 MODULE_ALIAS("platform:i2c_designware"); 428 429 static struct platform_driver dw_i2c_driver = { 430 .probe = dw_i2c_plat_probe, 431 .remove = dw_i2c_plat_remove, 432 .driver = { 433 .name = "i2c_designware", 434 .of_match_table = of_match_ptr(dw_i2c_of_match), 435 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match), 436 .pm = DW_I2C_DEV_PMOPS, 437 }, 438 }; 439 440 static int __init dw_i2c_init_driver(void) 441 { 442 return platform_driver_register(&dw_i2c_driver); 443 } 444 subsys_initcall(dw_i2c_init_driver); 445 446 static void __exit dw_i2c_exit_driver(void) 447 { 448 platform_driver_unregister(&dw_i2c_driver); 449 } 450 module_exit(dw_i2c_exit_driver); 451 452 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); 453 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter"); 454 MODULE_LICENSE("GPL"); 455