drivers/i2c/busses/i2c-at91-core.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  i2c Support for Atmel's AT91 Two-Wire Interface (TWI)
   4  *
   5  *  Copyright (C) 2011 Weinmann Medical GmbH
   6  *  Author: Nikolaus Voss <n.voss@weinmann.de>
   7  *
   8  *  Evolved from original work by:
   9  *  Copyright (C) 2004 Rick Bronson
  10  *  Converted to 2.6 by Andrew Victor <andrew@sanpeople.com>
  11  *
  12  *  Borrowed heavily from original work by:
  13  *  Copyright (C) 2000 Philip Edelbrock <phil@stimpy.netroedge.com>
  14  */
  15
  16 #include <linux/clk.h>
  17 #include <linux/err.h>
  18 #include <linux/i2c.h>
  19 #include <linux/io.h>
  20 #include <linux/module.h>
  21 #include <linux/of.h>
  22 #include <linux/of_device.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/pm_runtime.h>
  25 #include <linux/pinctrl/consumer.h>
  26
  27 #include "i2c-at91.h"
  28
  29 unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg)
  30 {
  31         return readl_relaxed(dev->base + reg);
  32 }
  33
  34 void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val)
  35 {
  36         writel_relaxed(val, dev->base + reg);
  37 }
  38
  39 void at91_disable_twi_interrupts(struct at91_twi_dev *dev)
  40 {
  41         at91_twi_write(dev, AT91_TWI_IDR, AT91_TWI_INT_MASK);
  42 }
  43
  44 void at91_twi_irq_save(struct at91_twi_dev *dev)
  45 {
  46         dev->imr = at91_twi_read(dev, AT91_TWI_IMR) & AT91_TWI_INT_MASK;
  47         at91_disable_twi_interrupts(dev);
  48 }
  49
  50 void at91_twi_irq_restore(struct at91_twi_dev *dev)
  51 {
  52         at91_twi_write(dev, AT91_TWI_IER, dev->imr);
  53 }
  54
  55 void at91_init_twi_bus(struct at91_twi_dev *dev)
  56 {
  57         at91_disable_twi_interrupts(dev);
  58         at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SWRST);
  59         if (dev->slave_detected)
  60                 at91_init_twi_bus_slave(dev);
  61         else
  62                 at91_init_twi_bus_master(dev);
  63 }
  64
  65 static struct at91_twi_pdata at91rm9200_config = {
  66         .clk_max_div = 5,
  67         .clk_offset = 3,
  68         .has_unre_flag = true,
  69         .has_alt_cmd = false,
  70         .has_hold_field = false,
  71         .has_dig_filtr = false,
  72         .has_adv_dig_filtr = false,
  73         .has_ana_filtr = false,
  74 };
  75
  76 static struct at91_twi_pdata at91sam9261_config = {
  77         .clk_max_div = 5,
  78         .clk_offset = 4,
  79         .has_unre_flag = false,
  80         .has_alt_cmd = false,
  81         .has_hold_field = false,
  82         .has_dig_filtr = false,
  83         .has_adv_dig_filtr = false,
  84         .has_ana_filtr = false,
  85 };
  86
  87 static struct at91_twi_pdata at91sam9260_config = {
  88         .clk_max_div = 7,
  89         .clk_offset = 4,
  90         .has_unre_flag = false,
  91         .has_alt_cmd = false,
  92         .has_hold_field = false,
  93         .has_dig_filtr = false,
  94         .has_adv_dig_filtr = false,
  95         .has_ana_filtr = false,
  96 };
  97
  98 static struct at91_twi_pdata at91sam9g20_config = {
  99         .clk_max_div = 7,
 100         .clk_offset = 4,
 101         .has_unre_flag = false,
 102         .has_alt_cmd = false,
 103         .has_hold_field = false,
 104         .has_dig_filtr = false,
 105         .has_adv_dig_filtr = false,
 106         .has_ana_filtr = false,
 107 };
 108
 109 static struct at91_twi_pdata at91sam9g10_config = {
 110         .clk_max_div = 7,
 111         .clk_offset = 4,
 112         .has_unre_flag = false,
 113         .has_alt_cmd = false,
 114         .has_hold_field = false,
 115         .has_dig_filtr = false,
 116         .has_adv_dig_filtr = false,
 117         .has_ana_filtr = false,
 118 };
 119
 120 static const struct platform_device_id at91_twi_devtypes[] = {
 121         {
 122                 .name = "i2c-at91rm9200",
 123                 .driver_data = (unsigned long) &at91rm9200_config,
 124         }, {
 125                 .name = "i2c-at91sam9261",
 126                 .driver_data = (unsigned long) &at91sam9261_config,
 127         }, {
 128                 .name = "i2c-at91sam9260",
 129                 .driver_data = (unsigned long) &at91sam9260_config,
 130         }, {
 131                 .name = "i2c-at91sam9g20",
 132                 .driver_data = (unsigned long) &at91sam9g20_config,
 133         }, {
 134                 .name = "i2c-at91sam9g10",
 135                 .driver_data = (unsigned long) &at91sam9g10_config,
 136         }, {
 137                 /* sentinel */
 138         }
 139 };
 140
 141 #if defined(CONFIG_OF)
 142 static struct at91_twi_pdata at91sam9x5_config = {
 143         .clk_max_div = 7,
 144         .clk_offset = 4,
 145         .has_unre_flag = false,
 146         .has_alt_cmd = false,
 147         .has_hold_field = false,
 148         .has_dig_filtr = false,
 149         .has_adv_dig_filtr = false,
 150         .has_ana_filtr = false,
 151 };
 152
 153 static struct at91_twi_pdata sama5d4_config = {
 154         .clk_max_div = 7,
 155         .clk_offset = 4,
 156         .has_unre_flag = false,
 157         .has_alt_cmd = false,
 158         .has_hold_field = true,
 159         .has_dig_filtr = true,
 160         .has_adv_dig_filtr = false,
 161         .has_ana_filtr = false,
 162 };
 163
 164 static struct at91_twi_pdata sama5d2_config = {
 165         .clk_max_div = 7,
 166         .clk_offset = 3,
 167         .has_unre_flag = true,
 168         .has_alt_cmd = true,
 169         .has_hold_field = true,
 170         .has_dig_filtr = true,
 171         .has_adv_dig_filtr = true,
 172         .has_ana_filtr = true,
 173 };
 174
 175 static struct at91_twi_pdata sam9x60_config = {
 176         .clk_max_div = 7,
 177         .clk_offset = 3,
 178         .has_unre_flag = true,
 179         .has_alt_cmd = true,
 180         .has_hold_field = true,
 181         .has_dig_filtr = true,
 182         .has_adv_dig_filtr = true,
 183         .has_ana_filtr = true,
 184 };
 185
 186 static const struct of_device_id atmel_twi_dt_ids[] = {
 187         {
 188                 .compatible = "atmel,at91rm9200-i2c",
 189                 .data = &at91rm9200_config,
 190         }, {
 191                 .compatible = "atmel,at91sam9260-i2c",
 192                 .data = &at91sam9260_config,
 193         }, {
 194                 .compatible = "atmel,at91sam9261-i2c",
 195                 .data = &at91sam9261_config,
 196         }, {
 197                 .compatible = "atmel,at91sam9g20-i2c",
 198                 .data = &at91sam9g20_config,
 199         }, {
 200                 .compatible = "atmel,at91sam9g10-i2c",
 201                 .data = &at91sam9g10_config,
 202         }, {
 203                 .compatible = "atmel,at91sam9x5-i2c",
 204                 .data = &at91sam9x5_config,
 205         }, {
 206                 .compatible = "atmel,sama5d4-i2c",
 207                 .data = &sama5d4_config,
 208         }, {
 209                 .compatible = "atmel,sama5d2-i2c",
 210                 .data = &sama5d2_config,
 211         }, {
 212                 .compatible = "microchip,sam9x60-i2c",
 213                 .data = &sam9x60_config,
 214         }, {
 215                 /* sentinel */
 216         }
 217 };
 218 MODULE_DEVICE_TABLE(of, atmel_twi_dt_ids);
 219 #endif
 220
 221 static struct at91_twi_pdata *at91_twi_get_driver_data(
 222                                         struct platform_device *pdev)
 223 {
 224         if (pdev->dev.of_node) {
 225                 const struct of_device_id *match;
 226                 match = of_match_node(atmel_twi_dt_ids, pdev->dev.of_node);
 227                 if (!match)
 228                         return NULL;
 229                 return (struct at91_twi_pdata *)match->data;
 230         }
 231         return (struct at91_twi_pdata *) platform_get_device_id(pdev)->driver_data;
 232 }
 233
 234 static int at91_twi_probe(struct platform_device *pdev)
 235 {
 236         struct at91_twi_dev *dev;
 237         struct resource *mem;
 238         int rc;
 239         u32 phy_addr;
 240
 241         dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
 242         if (!dev)
 243                 return -ENOMEM;
 244
 245         dev->dev = &pdev->dev;
 246
 247         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 248         if (!mem)
 249                 return -ENODEV;
 250         phy_addr = mem->start;
 251
 252         dev->pdata = at91_twi_get_driver_data(pdev);
 253         if (!dev->pdata)
 254                 return -ENODEV;
 255
 256         dev->base = devm_ioremap_resource(&pdev->dev, mem);
 257         if (IS_ERR(dev->base))
 258                 return PTR_ERR(dev->base);
 259
 260         dev->irq = platform_get_irq(pdev, 0);
 261         if (dev->irq < 0)
 262                 return dev->irq;
 263
 264         platform_set_drvdata(pdev, dev);
 265
 266         dev->clk = devm_clk_get(dev->dev, NULL);
 267         if (IS_ERR(dev->clk)) {
 268                 dev_err(dev->dev, "no clock defined\n");
 269                 return -ENODEV;
 270         }
 271         clk_prepare_enable(dev->clk);
 272
 273         snprintf(dev->adapter.name, sizeof(dev->adapter.name), "AT91");
 274         i2c_set_adapdata(&dev->adapter, dev);
 275         dev->adapter.owner = THIS_MODULE;
 276         dev->adapter.class = I2C_CLASS_DEPRECATED;
 277         dev->adapter.dev.parent = dev->dev;
 278         dev->adapter.nr = pdev->id;
 279         dev->adapter.timeout = AT91_I2C_TIMEOUT;
 280         dev->adapter.dev.of_node = pdev->dev.of_node;
 281
 282         dev->slave_detected = i2c_detect_slave_mode(&pdev->dev);
 283
 284         if (dev->slave_detected)
 285                 rc = at91_twi_probe_slave(pdev, phy_addr, dev);
 286         else
 287                 rc = at91_twi_probe_master(pdev, phy_addr, dev);
 288         if (rc)
 289                 return rc;
 290
 291         at91_init_twi_bus(dev);
 292
 293         pm_runtime_set_autosuspend_delay(dev->dev, AUTOSUSPEND_TIMEOUT);
 294         pm_runtime_use_autosuspend(dev->dev);
 295         pm_runtime_set_active(dev->dev);
 296         pm_runtime_enable(dev->dev);
 297
 298         rc = i2c_add_numbered_adapter(&dev->adapter);
 299         if (rc) {
 300                 clk_disable_unprepare(dev->clk);
 301
 302                 pm_runtime_disable(dev->dev);
 303                 pm_runtime_set_suspended(dev->dev);
 304
 305                 return rc;
 306         }
 307
 308         dev_info(dev->dev, "AT91 i2c bus driver (hw version: %#x).\n",
 309                  at91_twi_read(dev, AT91_TWI_VER));
 310         return 0;
 311 }
 312
 313 static int at91_twi_remove(struct platform_device *pdev)
 314 {
 315         struct at91_twi_dev *dev = platform_get_drvdata(pdev);
 316
 317         i2c_del_adapter(&dev->adapter);
 318         clk_disable_unprepare(dev->clk);
 319
 320         pm_runtime_disable(dev->dev);
 321         pm_runtime_set_suspended(dev->dev);
 322
 323         return 0;
 324 }
 325
 326 #ifdef CONFIG_PM
 327
 328 static int at91_twi_runtime_suspend(struct device *dev)
 329 {
 330         struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
 331
 332         clk_disable_unprepare(twi_dev->clk);
 333
 334         pinctrl_pm_select_sleep_state(dev);
 335
 336         return 0;
 337 }
 338
 339 static int at91_twi_runtime_resume(struct device *dev)
 340 {
 341         struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
 342
 343         pinctrl_pm_select_default_state(dev);
 344
 345         return clk_prepare_enable(twi_dev->clk);
 346 }
 347
 348 static int at91_twi_suspend_noirq(struct device *dev)
 349 {
 350         if (!pm_runtime_status_suspended(dev))
 351                 at91_twi_runtime_suspend(dev);
 352
 353         return 0;
 354 }
 355
 356 static int at91_twi_resume_noirq(struct device *dev)
 357 {
 358         struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
 359         int ret;
 360
 361         if (!pm_runtime_status_suspended(dev)) {
 362                 ret = at91_twi_runtime_resume(dev);
 363                 if (ret)
 364                         return ret;
 365         }
 366
 367         pm_runtime_mark_last_busy(dev);
 368         pm_request_autosuspend(dev);
 369
 370         at91_init_twi_bus(twi_dev);
 371
 372         return 0;
 373 }
 374
 375 static const struct dev_pm_ops at91_twi_pm = {
 376         .suspend_noirq  = at91_twi_suspend_noirq,
 377         .resume_noirq   = at91_twi_resume_noirq,
 378         .runtime_suspend        = at91_twi_runtime_suspend,
 379         .runtime_resume         = at91_twi_runtime_resume,
 380 };
 381
 382 #define at91_twi_pm_ops (&at91_twi_pm)
 383 #else
 384 #define at91_twi_pm_ops NULL
 385 #endif
 386
 387 static struct platform_driver at91_twi_driver = {
 388         .probe          = at91_twi_probe,
 389         .remove         = at91_twi_remove,
 390         .id_table       = at91_twi_devtypes,
 391         .driver         = {
 392                 .name   = "at91_i2c",
 393                 .of_match_table = of_match_ptr(atmel_twi_dt_ids),
 394                 .pm     = at91_twi_pm_ops,
 395         },
 396 };
 397
 398 static int __init at91_twi_init(void)
 399 {
 400         return platform_driver_register(&at91_twi_driver);
 401 }
 402
 403 static void __exit at91_twi_exit(void)
 404 {
 405         platform_driver_unregister(&at91_twi_driver);
 406 }
 407
 408 subsys_initcall(at91_twi_init);
 409 module_exit(at91_twi_exit);
 410
 411 MODULE_AUTHOR("Nikolaus Voss <n.voss@weinmann.de>");
 412 MODULE_DESCRIPTION("I2C (TWI) driver for Atmel AT91");
 413 MODULE_LICENSE("GPL");
 414 MODULE_ALIAS("platform:at91_i2c");