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/platform_device.h>
  23 #include <linux/pm_runtime.h>
  24 #include <linux/pinctrl/consumer.h>
  25
  26 #include "i2c-at91.h"
  27
  28 unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg)
  29 {
  30         return readl_relaxed(dev->base + reg);
  31 }
  32
  33 void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val)
  34 {
  35         writel_relaxed(val, dev->base + reg);
  36 }
  37
  38 void at91_disable_twi_interrupts(struct at91_twi_dev *dev)
  39 {
  40         at91_twi_write(dev, AT91_TWI_IDR, AT91_TWI_INT_MASK);
  41 }
  42
  43 void at91_twi_irq_save(struct at91_twi_dev *dev)
  44 {
  45         dev->imr = at91_twi_read(dev, AT91_TWI_IMR) & AT91_TWI_INT_MASK;
  46         at91_disable_twi_interrupts(dev);
  47 }
  48
  49 void at91_twi_irq_restore(struct at91_twi_dev *dev)
  50 {
  51         at91_twi_write(dev, AT91_TWI_IER, dev->imr);
  52 }
  53
  54 void at91_init_twi_bus(struct at91_twi_dev *dev)
  55 {
  56         at91_disable_twi_interrupts(dev);
  57         at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SWRST);
  58         if (dev->slave_detected)
  59                 at91_init_twi_bus_slave(dev);
  60         else
  61                 at91_init_twi_bus_master(dev);
  62 }
  63
  64 static struct at91_twi_pdata at91rm9200_config = {
  65         .clk_max_div = 5,
  66         .clk_offset = 3,
  67         .has_unre_flag = true,
  68 };
  69
  70 static struct at91_twi_pdata at91sam9261_config = {
  71         .clk_max_div = 5,
  72         .clk_offset = 4,
  73 };
  74
  75 static struct at91_twi_pdata at91sam9260_config = {
  76         .clk_max_div = 7,
  77         .clk_offset = 4,
  78 };
  79
  80 static struct at91_twi_pdata at91sam9g20_config = {
  81         .clk_max_div = 7,
  82         .clk_offset = 4,
  83 };
  84
  85 static struct at91_twi_pdata at91sam9g10_config = {
  86         .clk_max_div = 7,
  87         .clk_offset = 4,
  88 };
  89
  90 static const struct platform_device_id at91_twi_devtypes[] = {
  91         {
  92                 .name = "i2c-at91rm9200",
  93                 .driver_data = (unsigned long) &at91rm9200_config,
  94         }, {
  95                 .name = "i2c-at91sam9261",
  96                 .driver_data = (unsigned long) &at91sam9261_config,
  97         }, {
  98                 .name = "i2c-at91sam9260",
  99                 .driver_data = (unsigned long) &at91sam9260_config,
 100         }, {
 101                 .name = "i2c-at91sam9g20",
 102                 .driver_data = (unsigned long) &at91sam9g20_config,
 103         }, {
 104                 .name = "i2c-at91sam9g10",
 105                 .driver_data = (unsigned long) &at91sam9g10_config,
 106         }, {
 107                 /* sentinel */
 108         }
 109 };
 110
 111 #if defined(CONFIG_OF)
 112 static struct at91_twi_pdata at91sam9x5_config = {
 113         .clk_max_div = 7,
 114         .clk_offset = 4,
 115 };
 116
 117 static struct at91_twi_pdata sama5d4_config = {
 118         .clk_max_div = 7,
 119         .clk_offset = 4,
 120         .has_hold_field = true,
 121         .has_dig_filtr = true,
 122 };
 123
 124 static struct at91_twi_pdata sama5d2_config = {
 125         .clk_max_div = 7,
 126         .clk_offset = 3,
 127         .has_unre_flag = true,
 128         .has_alt_cmd = true,
 129         .has_hold_field = true,
 130         .has_dig_filtr = true,
 131         .has_adv_dig_filtr = true,
 132         .has_ana_filtr = true,
 133         .has_clear_cmd = false, /* due to errata, CLEAR cmd is not working */
 134 };
 135
 136 static struct at91_twi_pdata sam9x60_config = {
 137         .clk_max_div = 7,
 138         .clk_offset = 3,
 139         .has_unre_flag = true,
 140         .has_alt_cmd = true,
 141         .has_hold_field = true,
 142         .has_dig_filtr = true,
 143         .has_adv_dig_filtr = true,
 144         .has_ana_filtr = true,
 145         .has_clear_cmd = true,
 146 };
 147
 148 static const struct of_device_id atmel_twi_dt_ids[] = {
 149         {
 150                 .compatible = "atmel,at91rm9200-i2c",
 151                 .data = &at91rm9200_config,
 152         }, {
 153                 .compatible = "atmel,at91sam9260-i2c",
 154                 .data = &at91sam9260_config,
 155         }, {
 156                 .compatible = "atmel,at91sam9261-i2c",
 157                 .data = &at91sam9261_config,
 158         }, {
 159                 .compatible = "atmel,at91sam9g20-i2c",
 160                 .data = &at91sam9g20_config,
 161         }, {
 162                 .compatible = "atmel,at91sam9g10-i2c",
 163                 .data = &at91sam9g10_config,
 164         }, {
 165                 .compatible = "atmel,at91sam9x5-i2c",
 166                 .data = &at91sam9x5_config,
 167         }, {
 168                 .compatible = "atmel,sama5d4-i2c",
 169                 .data = &sama5d4_config,
 170         }, {
 171                 .compatible = "atmel,sama5d2-i2c",
 172                 .data = &sama5d2_config,
 173         }, {
 174                 .compatible = "microchip,sam9x60-i2c",
 175                 .data = &sam9x60_config,
 176         }, {
 177                 /* sentinel */
 178         }
 179 };
 180 MODULE_DEVICE_TABLE(of, atmel_twi_dt_ids);
 181 #endif
 182
 183 static struct at91_twi_pdata *at91_twi_get_driver_data(
 184                                         struct platform_device *pdev)
 185 {
 186         if (pdev->dev.of_node) {
 187                 const struct of_device_id *match;
 188                 match = of_match_node(atmel_twi_dt_ids, pdev->dev.of_node);
 189                 if (!match)
 190                         return NULL;
 191                 return (struct at91_twi_pdata *)match->data;
 192         }
 193         return (struct at91_twi_pdata *) platform_get_device_id(pdev)->driver_data;
 194 }
 195
 196 static int at91_twi_probe(struct platform_device *pdev)
 197 {
 198         struct at91_twi_dev *dev;
 199         struct resource *mem;
 200         int rc;
 201         u32 phy_addr;
 202
 203         dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
 204         if (!dev)
 205                 return -ENOMEM;
 206
 207         dev->dev = &pdev->dev;
 208
 209         dev->base = devm_platform_get_and_ioremap_resource(pdev, 0, &mem);
 210         if (IS_ERR(dev->base))
 211                 return PTR_ERR(dev->base);
 212         phy_addr = mem->start;
 213
 214         dev->pdata = at91_twi_get_driver_data(pdev);
 215         if (!dev->pdata)
 216                 return -ENODEV;
 217
 218         dev->irq = platform_get_irq(pdev, 0);
 219         if (dev->irq < 0)
 220                 return dev->irq;
 221
 222         platform_set_drvdata(pdev, dev);
 223
 224         dev->clk = devm_clk_get_enabled(dev->dev, NULL);
 225         if (IS_ERR(dev->clk))
 226                 return dev_err_probe(dev->dev, PTR_ERR(dev->clk),
 227                                      "failed to enable clock\n");
 228
 229         snprintf(dev->adapter.name, sizeof(dev->adapter.name), "AT91");
 230         i2c_set_adapdata(&dev->adapter, dev);
 231         dev->adapter.owner = THIS_MODULE;
 232         dev->adapter.class = I2C_CLASS_DEPRECATED;
 233         dev->adapter.dev.parent = dev->dev;
 234         dev->adapter.nr = pdev->id;
 235         dev->adapter.timeout = AT91_I2C_TIMEOUT;
 236         dev->adapter.dev.of_node = pdev->dev.of_node;
 237
 238         dev->slave_detected = i2c_detect_slave_mode(&pdev->dev);
 239
 240         if (dev->slave_detected)
 241                 rc = at91_twi_probe_slave(pdev, phy_addr, dev);
 242         else
 243                 rc = at91_twi_probe_master(pdev, phy_addr, dev);
 244         if (rc)
 245                 return rc;
 246
 247         at91_init_twi_bus(dev);
 248
 249         pm_runtime_set_autosuspend_delay(dev->dev, AUTOSUSPEND_TIMEOUT);
 250         pm_runtime_use_autosuspend(dev->dev);
 251         pm_runtime_set_active(dev->dev);
 252         pm_runtime_enable(dev->dev);
 253
 254         rc = i2c_add_numbered_adapter(&dev->adapter);
 255         if (rc) {
 256                 pm_runtime_disable(dev->dev);
 257                 pm_runtime_set_suspended(dev->dev);
 258
 259                 return rc;
 260         }
 261
 262         dev_info(dev->dev, "AT91 i2c bus driver (hw version: %#x).\n",
 263                  at91_twi_read(dev, AT91_TWI_VER));
 264         return 0;
 265 }
 266
 267 static void at91_twi_remove(struct platform_device *pdev)
 268 {
 269         struct at91_twi_dev *dev = platform_get_drvdata(pdev);
 270
 271         i2c_del_adapter(&dev->adapter);
 272
 273         pm_runtime_disable(dev->dev);
 274         pm_runtime_set_suspended(dev->dev);
 275 }
 276
 277 static int __maybe_unused at91_twi_runtime_suspend(struct device *dev)
 278 {
 279         struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
 280
 281         clk_disable_unprepare(twi_dev->clk);
 282
 283         pinctrl_pm_select_sleep_state(dev);
 284
 285         return 0;
 286 }
 287
 288 static int __maybe_unused at91_twi_runtime_resume(struct device *dev)
 289 {
 290         struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
 291
 292         pinctrl_pm_select_default_state(dev);
 293
 294         return clk_prepare_enable(twi_dev->clk);
 295 }
 296
 297 static int __maybe_unused at91_twi_suspend_noirq(struct device *dev)
 298 {
 299         if (!pm_runtime_status_suspended(dev))
 300                 at91_twi_runtime_suspend(dev);
 301
 302         return 0;
 303 }
 304
 305 static int __maybe_unused at91_twi_resume_noirq(struct device *dev)
 306 {
 307         struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
 308         int ret;
 309
 310         if (!pm_runtime_status_suspended(dev)) {
 311                 ret = at91_twi_runtime_resume(dev);
 312                 if (ret)
 313                         return ret;
 314         }
 315
 316         pm_runtime_mark_last_busy(dev);
 317         pm_request_autosuspend(dev);
 318
 319         at91_init_twi_bus(twi_dev);
 320
 321         return 0;
 322 }
 323
 324 static const struct dev_pm_ops __maybe_unused at91_twi_pm = {
 325         .suspend_noirq  = at91_twi_suspend_noirq,
 326         .resume_noirq   = at91_twi_resume_noirq,
 327         .runtime_suspend        = at91_twi_runtime_suspend,
 328         .runtime_resume         = at91_twi_runtime_resume,
 329 };
 330
 331 static struct platform_driver at91_twi_driver = {
 332         .probe          = at91_twi_probe,
 333         .remove_new     = at91_twi_remove,
 334         .id_table       = at91_twi_devtypes,
 335         .driver         = {
 336                 .name   = "at91_i2c",
 337                 .of_match_table = of_match_ptr(atmel_twi_dt_ids),
 338                 .pm     = pm_ptr(&at91_twi_pm),
 339         },
 340 };
 341
 342 static int __init at91_twi_init(void)
 343 {
 344         return platform_driver_register(&at91_twi_driver);
 345 }
 346
 347 static void __exit at91_twi_exit(void)
 348 {
 349         platform_driver_unregister(&at91_twi_driver);
 350 }
 351
 352 subsys_initcall(at91_twi_init);
 353 module_exit(at91_twi_exit);
 354
 355 MODULE_AUTHOR("Nikolaus Voss <n.voss@weinmann.de>");
 356 MODULE_DESCRIPTION("I2C (TWI) driver for Atmel AT91");
 357 MODULE_LICENSE("GPL");
 358 MODULE_ALIAS("platform:at91_i2c");