root/drivers/i2c/busses/i2c-designware-platdrv.c

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DEFINITIONS

This source file includes following definitions.
  1. i2c_dw_get_clk_rate_khz
  2. dw_i2c_acpi_params
  3. dw_i2c_acpi_configure
  4. dw_i2c_acpi_configure
  5. mscc_twi_set_sda_hold_time
  6. dw_i2c_of_configure
  7. dw_i2c_of_configure
  8. i2c_dw_configure_master
  9. i2c_dw_configure_slave
  10. dw_i2c_set_fifo_size
  11. dw_i2c_plat_pm_cleanup
  12. dw_i2c_plat_probe
  13. dw_i2c_plat_remove
  14. dw_i2c_plat_prepare
  15. dw_i2c_plat_complete
  16. dw_i2c_plat_suspend
  17. dw_i2c_plat_resume
  18. dw_i2c_init_driver
  19. dw_i2c_exit_driver

   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         if (dev->flags & ACCESS_NO_IRQ_SUSPEND) {
 374                 dev_pm_set_driver_flags(&pdev->dev,
 375                                         DPM_FLAG_SMART_PREPARE |
 376                                         DPM_FLAG_LEAVE_SUSPENDED);
 377         } else {
 378                 dev_pm_set_driver_flags(&pdev->dev,
 379                                         DPM_FLAG_SMART_PREPARE |
 380                                         DPM_FLAG_SMART_SUSPEND |
 381                                         DPM_FLAG_LEAVE_SUSPENDED);
 382         }
 383 
 384         /* The code below assumes runtime PM to be disabled. */
 385         WARN_ON(pm_runtime_enabled(&pdev->dev));
 386 
 387         pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
 388         pm_runtime_use_autosuspend(&pdev->dev);
 389         pm_runtime_set_active(&pdev->dev);
 390 
 391         if (dev->shared_with_punit)
 392                 pm_runtime_get_noresume(&pdev->dev);
 393 
 394         pm_runtime_enable(&pdev->dev);
 395 
 396         if (dev->mode == DW_IC_SLAVE)
 397                 ret = i2c_dw_probe_slave(dev);
 398         else
 399                 ret = i2c_dw_probe(dev);
 400 
 401         if (ret)
 402                 goto exit_probe;
 403 
 404         return ret;
 405 
 406 exit_probe:
 407         dw_i2c_plat_pm_cleanup(dev);
 408 exit_reset:
 409         reset_control_assert(dev->rst);
 410         return ret;
 411 }
 412 
 413 static int dw_i2c_plat_remove(struct platform_device *pdev)
 414 {
 415         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 416 
 417         pm_runtime_get_sync(&pdev->dev);
 418 
 419         i2c_del_adapter(&dev->adapter);
 420 
 421         dev->disable(dev);
 422 
 423         pm_runtime_dont_use_autosuspend(&pdev->dev);
 424         pm_runtime_put_sync(&pdev->dev);
 425         dw_i2c_plat_pm_cleanup(dev);
 426 
 427         reset_control_assert(dev->rst);
 428 
 429         return 0;
 430 }
 431 
 432 #ifdef CONFIG_PM_SLEEP
 433 static int dw_i2c_plat_prepare(struct device *dev)
 434 {
 435         /*
 436          * If the ACPI companion device object is present for this device, it
 437          * may be accessed during suspend and resume of other devices via I2C
 438          * operation regions, so tell the PM core and middle layers to avoid
 439          * skipping system suspend/resume callbacks for it in that case.
 440          */
 441         return !has_acpi_companion(dev);
 442 }
 443 
 444 static void dw_i2c_plat_complete(struct device *dev)
 445 {
 446         /*
 447          * The device can only be in runtime suspend at this point if it has not
 448          * been resumed throughout the ending system suspend/resume cycle, so if
 449          * the platform firmware might mess up with it, request the runtime PM
 450          * framework to resume it.
 451          */
 452         if (pm_runtime_suspended(dev) && pm_resume_via_firmware())
 453                 pm_request_resume(dev);
 454 }
 455 #else
 456 #define dw_i2c_plat_prepare     NULL
 457 #define dw_i2c_plat_complete    NULL
 458 #endif
 459 
 460 #ifdef CONFIG_PM
 461 static int dw_i2c_plat_suspend(struct device *dev)
 462 {
 463         struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
 464 
 465         i_dev->suspended = true;
 466 
 467         if (i_dev->shared_with_punit)
 468                 return 0;
 469 
 470         i_dev->disable(i_dev);
 471         i2c_dw_prepare_clk(i_dev, false);
 472 
 473         return 0;
 474 }
 475 
 476 static int dw_i2c_plat_resume(struct device *dev)
 477 {
 478         struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
 479 
 480         if (!i_dev->shared_with_punit)
 481                 i2c_dw_prepare_clk(i_dev, true);
 482 
 483         i_dev->init(i_dev);
 484         i_dev->suspended = false;
 485 
 486         return 0;
 487 }
 488 
 489 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
 490         .prepare = dw_i2c_plat_prepare,
 491         .complete = dw_i2c_plat_complete,
 492         SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
 493         SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
 494 };
 495 
 496 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
 497 #else
 498 #define DW_I2C_DEV_PMOPS NULL
 499 #endif
 500 
 501 /* Work with hotplug and coldplug */
 502 MODULE_ALIAS("platform:i2c_designware");
 503 
 504 static struct platform_driver dw_i2c_driver = {
 505         .probe = dw_i2c_plat_probe,
 506         .remove = dw_i2c_plat_remove,
 507         .driver         = {
 508                 .name   = "i2c_designware",
 509                 .of_match_table = of_match_ptr(dw_i2c_of_match),
 510                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
 511                 .pm     = DW_I2C_DEV_PMOPS,
 512         },
 513 };
 514 
 515 static int __init dw_i2c_init_driver(void)
 516 {
 517         return platform_driver_register(&dw_i2c_driver);
 518 }
 519 subsys_initcall(dw_i2c_init_driver);
 520 
 521 static void __exit dw_i2c_exit_driver(void)
 522 {
 523         platform_driver_unregister(&dw_i2c_driver);
 524 }
 525 module_exit(dw_i2c_exit_driver);
 526 
 527 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 528 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
 529 MODULE_LICENSE("GPL");

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