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