drivers/net/can/m_can/tcan4x5x-core.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // SPI to CAN driver for the Texas Instruments TCAN4x5x
   3 // Copyright (C) 2018-19 Texas Instruments Incorporated - http://www.ti.com/
   4
   5 #include "tcan4x5x.h"
   6
   7 #define TCAN4X5X_EXT_CLK_DEF 40000000
   8
   9 #define TCAN4X5X_DEV_ID0 0x00
  10 #define TCAN4X5X_DEV_ID1 0x04
  11 #define TCAN4X5X_REV 0x08
  12 #define TCAN4X5X_STATUS 0x0C
  13 #define TCAN4X5X_ERROR_STATUS 0x10
  14 #define TCAN4X5X_CONTROL 0x14
  15
  16 #define TCAN4X5X_CONFIG 0x800
  17 #define TCAN4X5X_TS_PRESCALE 0x804
  18 #define TCAN4X5X_TEST_REG 0x808
  19 #define TCAN4X5X_INT_FLAGS 0x820
  20 #define TCAN4X5X_MCAN_INT_REG 0x824
  21 #define TCAN4X5X_INT_EN 0x830
  22
  23 /* Interrupt bits */
  24 #define TCAN4X5X_CANBUSTERMOPEN_INT_EN BIT(30)
  25 #define TCAN4X5X_CANHCANL_INT_EN BIT(29)
  26 #define TCAN4X5X_CANHBAT_INT_EN BIT(28)
  27 #define TCAN4X5X_CANLGND_INT_EN BIT(27)
  28 #define TCAN4X5X_CANBUSOPEN_INT_EN BIT(26)
  29 #define TCAN4X5X_CANBUSGND_INT_EN BIT(25)
  30 #define TCAN4X5X_CANBUSBAT_INT_EN BIT(24)
  31 #define TCAN4X5X_UVSUP_INT_EN BIT(22)
  32 #define TCAN4X5X_UVIO_INT_EN BIT(21)
  33 #define TCAN4X5X_TSD_INT_EN BIT(19)
  34 #define TCAN4X5X_ECCERR_INT_EN BIT(16)
  35 #define TCAN4X5X_CANINT_INT_EN BIT(15)
  36 #define TCAN4X5X_LWU_INT_EN BIT(14)
  37 #define TCAN4X5X_CANSLNT_INT_EN BIT(10)
  38 #define TCAN4X5X_CANDOM_INT_EN BIT(8)
  39 #define TCAN4X5X_CANBUS_ERR_INT_EN BIT(5)
  40 #define TCAN4X5X_BUS_FAULT BIT(4)
  41 #define TCAN4X5X_MCAN_INT BIT(1)
  42 #define TCAN4X5X_ENABLE_TCAN_INT \
  43         (TCAN4X5X_MCAN_INT | TCAN4X5X_BUS_FAULT | \
  44          TCAN4X5X_CANBUS_ERR_INT_EN | TCAN4X5X_CANINT_INT_EN)
  45
  46 /* MCAN Interrupt bits */
  47 #define TCAN4X5X_MCAN_IR_ARA BIT(29)
  48 #define TCAN4X5X_MCAN_IR_PED BIT(28)
  49 #define TCAN4X5X_MCAN_IR_PEA BIT(27)
  50 #define TCAN4X5X_MCAN_IR_WD BIT(26)
  51 #define TCAN4X5X_MCAN_IR_BO BIT(25)
  52 #define TCAN4X5X_MCAN_IR_EW BIT(24)
  53 #define TCAN4X5X_MCAN_IR_EP BIT(23)
  54 #define TCAN4X5X_MCAN_IR_ELO BIT(22)
  55 #define TCAN4X5X_MCAN_IR_BEU BIT(21)
  56 #define TCAN4X5X_MCAN_IR_BEC BIT(20)
  57 #define TCAN4X5X_MCAN_IR_DRX BIT(19)
  58 #define TCAN4X5X_MCAN_IR_TOO BIT(18)
  59 #define TCAN4X5X_MCAN_IR_MRAF BIT(17)
  60 #define TCAN4X5X_MCAN_IR_TSW BIT(16)
  61 #define TCAN4X5X_MCAN_IR_TEFL BIT(15)
  62 #define TCAN4X5X_MCAN_IR_TEFF BIT(14)
  63 #define TCAN4X5X_MCAN_IR_TEFW BIT(13)
  64 #define TCAN4X5X_MCAN_IR_TEFN BIT(12)
  65 #define TCAN4X5X_MCAN_IR_TFE BIT(11)
  66 #define TCAN4X5X_MCAN_IR_TCF BIT(10)
  67 #define TCAN4X5X_MCAN_IR_TC BIT(9)
  68 #define TCAN4X5X_MCAN_IR_HPM BIT(8)
  69 #define TCAN4X5X_MCAN_IR_RF1L BIT(7)
  70 #define TCAN4X5X_MCAN_IR_RF1F BIT(6)
  71 #define TCAN4X5X_MCAN_IR_RF1W BIT(5)
  72 #define TCAN4X5X_MCAN_IR_RF1N BIT(4)
  73 #define TCAN4X5X_MCAN_IR_RF0L BIT(3)
  74 #define TCAN4X5X_MCAN_IR_RF0F BIT(2)
  75 #define TCAN4X5X_MCAN_IR_RF0W BIT(1)
  76 #define TCAN4X5X_MCAN_IR_RF0N BIT(0)
  77 #define TCAN4X5X_ENABLE_MCAN_INT \
  78         (TCAN4X5X_MCAN_IR_TC | TCAN4X5X_MCAN_IR_RF0N | \
  79          TCAN4X5X_MCAN_IR_RF1N | TCAN4X5X_MCAN_IR_RF0F | \
  80          TCAN4X5X_MCAN_IR_RF1F)
  81
  82 #define TCAN4X5X_MRAM_START 0x8000
  83 #define TCAN4X5X_MCAN_OFFSET 0x1000
  84
  85 #define TCAN4X5X_CLEAR_ALL_INT 0xffffffff
  86 #define TCAN4X5X_SET_ALL_INT 0xffffffff
  87
  88 #define TCAN4X5X_MODE_SEL_MASK (BIT(7) | BIT(6))
  89 #define TCAN4X5X_MODE_SLEEP 0x00
  90 #define TCAN4X5X_MODE_STANDBY BIT(6)
  91 #define TCAN4X5X_MODE_NORMAL BIT(7)
  92
  93 #define TCAN4X5X_DISABLE_WAKE_MSK       (BIT(31) | BIT(30))
  94 #define TCAN4X5X_DISABLE_INH_MSK        BIT(9)
  95
  96 #define TCAN4X5X_SW_RESET BIT(2)
  97
  98 #define TCAN4X5X_MCAN_CONFIGURED BIT(5)
  99 #define TCAN4X5X_WATCHDOG_EN BIT(3)
 100 #define TCAN4X5X_WD_60_MS_TIMER 0
 101 #define TCAN4X5X_WD_600_MS_TIMER BIT(28)
 102 #define TCAN4X5X_WD_3_S_TIMER BIT(29)
 103 #define TCAN4X5X_WD_6_S_TIMER (BIT(28) | BIT(29))
 104
 105 static inline struct tcan4x5x_priv *cdev_to_priv(struct m_can_classdev *cdev)
 106 {
 107         return container_of(cdev, struct tcan4x5x_priv, cdev);
 108
 109 }
 110
 111 static void tcan4x5x_check_wake(struct tcan4x5x_priv *priv)
 112 {
 113         int wake_state = 0;
 114
 115         if (priv->device_state_gpio)
 116                 wake_state = gpiod_get_value(priv->device_state_gpio);
 117
 118         if (priv->device_wake_gpio && wake_state) {
 119                 gpiod_set_value(priv->device_wake_gpio, 0);
 120                 usleep_range(5, 50);
 121                 gpiod_set_value(priv->device_wake_gpio, 1);
 122         }
 123 }
 124
 125 static int tcan4x5x_reset(struct tcan4x5x_priv *priv)
 126 {
 127         int ret = 0;
 128
 129         if (priv->reset_gpio) {
 130                 gpiod_set_value(priv->reset_gpio, 1);
 131
 132                 /* tpulse_width minimum 30us */
 133                 usleep_range(30, 100);
 134                 gpiod_set_value(priv->reset_gpio, 0);
 135         } else {
 136                 ret = regmap_write(priv->regmap, TCAN4X5X_CONFIG,
 137                                    TCAN4X5X_SW_RESET);
 138                 if (ret)
 139                         return ret;
 140         }
 141
 142         usleep_range(700, 1000);
 143
 144         return ret;
 145 }
 146
 147 static u32 tcan4x5x_read_reg(struct m_can_classdev *cdev, int reg)
 148 {
 149         struct tcan4x5x_priv *priv = cdev_to_priv(cdev);
 150         u32 val;
 151
 152         regmap_read(priv->regmap, TCAN4X5X_MCAN_OFFSET + reg, &val);
 153
 154         return val;
 155 }
 156
 157 static u32 tcan4x5x_read_fifo(struct m_can_classdev *cdev, int addr_offset)
 158 {
 159         struct tcan4x5x_priv *priv = cdev_to_priv(cdev);
 160         u32 val;
 161
 162         regmap_read(priv->regmap, TCAN4X5X_MRAM_START + addr_offset, &val);
 163
 164         return val;
 165 }
 166
 167 static int tcan4x5x_write_reg(struct m_can_classdev *cdev, int reg, int val)
 168 {
 169         struct tcan4x5x_priv *priv = cdev_to_priv(cdev);
 170
 171         return regmap_write(priv->regmap, TCAN4X5X_MCAN_OFFSET + reg, val);
 172 }
 173
 174 static int tcan4x5x_write_fifo(struct m_can_classdev *cdev,
 175                                int addr_offset, int val)
 176 {
 177         struct tcan4x5x_priv *priv = cdev_to_priv(cdev);
 178
 179         return regmap_write(priv->regmap, TCAN4X5X_MRAM_START + addr_offset, val);
 180 }
 181
 182 static int tcan4x5x_power_enable(struct regulator *reg, int enable)
 183 {
 184         if (IS_ERR_OR_NULL(reg))
 185                 return 0;
 186
 187         if (enable)
 188                 return regulator_enable(reg);
 189         else
 190                 return regulator_disable(reg);
 191 }
 192
 193 static int tcan4x5x_write_tcan_reg(struct m_can_classdev *cdev,
 194                                    int reg, int val)
 195 {
 196         struct tcan4x5x_priv *priv = cdev_to_priv(cdev);
 197
 198         return regmap_write(priv->regmap, reg, val);
 199 }
 200
 201 static int tcan4x5x_clear_interrupts(struct m_can_classdev *cdev)
 202 {
 203         int ret;
 204
 205         ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_STATUS,
 206                                       TCAN4X5X_CLEAR_ALL_INT);
 207         if (ret)
 208                 return ret;
 209
 210         ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_MCAN_INT_REG,
 211                                       TCAN4X5X_ENABLE_MCAN_INT);
 212         if (ret)
 213                 return ret;
 214
 215         ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_INT_FLAGS,
 216                                       TCAN4X5X_CLEAR_ALL_INT);
 217         if (ret)
 218                 return ret;
 219
 220         return tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_ERROR_STATUS,
 221                                        TCAN4X5X_CLEAR_ALL_INT);
 222 }
 223
 224 static int tcan4x5x_init(struct m_can_classdev *cdev)
 225 {
 226         struct tcan4x5x_priv *tcan4x5x = cdev_to_priv(cdev);
 227         int ret;
 228
 229         tcan4x5x_check_wake(tcan4x5x);
 230
 231         ret = tcan4x5x_clear_interrupts(cdev);
 232         if (ret)
 233                 return ret;
 234
 235         ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_INT_EN,
 236                                       TCAN4X5X_ENABLE_TCAN_INT);
 237         if (ret)
 238                 return ret;
 239
 240         /* Zero out the MCAN buffers */
 241         m_can_init_ram(cdev);
 242
 243         ret = regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG,
 244                                  TCAN4X5X_MODE_SEL_MASK, TCAN4X5X_MODE_NORMAL);
 245         if (ret)
 246                 return ret;
 247
 248         return ret;
 249 }
 250
 251 static int tcan4x5x_disable_wake(struct m_can_classdev *cdev)
 252 {
 253         struct tcan4x5x_priv *tcan4x5x = cdev_to_priv(cdev);
 254
 255         return regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG,
 256                                   TCAN4X5X_DISABLE_WAKE_MSK, 0x00);
 257 }
 258
 259 static int tcan4x5x_disable_state(struct m_can_classdev *cdev)
 260 {
 261         struct tcan4x5x_priv *tcan4x5x = cdev_to_priv(cdev);
 262
 263         return regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG,
 264                                   TCAN4X5X_DISABLE_INH_MSK, 0x01);
 265 }
 266
 267 static int tcan4x5x_get_gpios(struct m_can_classdev *cdev)
 268 {
 269         struct tcan4x5x_priv *tcan4x5x = cdev_to_priv(cdev);
 270         int ret;
 271
 272         tcan4x5x->device_wake_gpio = devm_gpiod_get(cdev->dev, "device-wake",
 273                                                     GPIOD_OUT_HIGH);
 274         if (IS_ERR(tcan4x5x->device_wake_gpio)) {
 275                 if (PTR_ERR(tcan4x5x->device_wake_gpio) == -EPROBE_DEFER)
 276                         return -EPROBE_DEFER;
 277
 278                 tcan4x5x_disable_wake(cdev);
 279         }
 280
 281         tcan4x5x->reset_gpio = devm_gpiod_get_optional(cdev->dev, "reset",
 282                                                        GPIOD_OUT_LOW);
 283         if (IS_ERR(tcan4x5x->reset_gpio))
 284                 tcan4x5x->reset_gpio = NULL;
 285
 286         ret = tcan4x5x_reset(tcan4x5x);
 287         if (ret)
 288                 return ret;
 289
 290         tcan4x5x->device_state_gpio = devm_gpiod_get_optional(cdev->dev,
 291                                                               "device-state",
 292                                                               GPIOD_IN);
 293         if (IS_ERR(tcan4x5x->device_state_gpio)) {
 294                 tcan4x5x->device_state_gpio = NULL;
 295                 tcan4x5x_disable_state(cdev);
 296         }
 297
 298         return 0;
 299 }
 300
 301 static struct m_can_ops tcan4x5x_ops = {
 302         .init = tcan4x5x_init,
 303         .read_reg = tcan4x5x_read_reg,
 304         .write_reg = tcan4x5x_write_reg,
 305         .write_fifo = tcan4x5x_write_fifo,
 306         .read_fifo = tcan4x5x_read_fifo,
 307         .clear_interrupts = tcan4x5x_clear_interrupts,
 308 };
 309
 310 static int tcan4x5x_can_probe(struct spi_device *spi)
 311 {
 312         struct tcan4x5x_priv *priv;
 313         struct m_can_classdev *mcan_class;
 314         int freq, ret;
 315
 316         mcan_class = m_can_class_allocate_dev(&spi->dev,
 317                                               sizeof(struct tcan4x5x_priv));
 318         if (!mcan_class)
 319                 return -ENOMEM;
 320
 321         priv = cdev_to_priv(mcan_class);
 322
 323         priv->power = devm_regulator_get_optional(&spi->dev, "vsup");
 324         if (PTR_ERR(priv->power) == -EPROBE_DEFER) {
 325                 ret = -EPROBE_DEFER;
 326                 goto out_m_can_class_free_dev;
 327         } else {
 328                 priv->power = NULL;
 329         }
 330
 331         m_can_class_get_clocks(mcan_class);
 332         if (IS_ERR(mcan_class->cclk)) {
 333                 dev_err(&spi->dev, "no CAN clock source defined\n");
 334                 freq = TCAN4X5X_EXT_CLK_DEF;
 335         } else {
 336                 freq = clk_get_rate(mcan_class->cclk);
 337         }
 338
 339         /* Sanity check */
 340         if (freq < 20000000 || freq > TCAN4X5X_EXT_CLK_DEF) {
 341                 ret = -ERANGE;
 342                 goto out_m_can_class_free_dev;
 343         }
 344
 345         priv->spi = spi;
 346
 347         mcan_class->pm_clock_support = 0;
 348         mcan_class->can.clock.freq = freq;
 349         mcan_class->dev = &spi->dev;
 350         mcan_class->ops = &tcan4x5x_ops;
 351         mcan_class->is_peripheral = true;
 352         mcan_class->net->irq = spi->irq;
 353
 354         spi_set_drvdata(spi, priv);
 355
 356         /* Configure the SPI bus */
 357         spi->bits_per_word = 8;
 358         ret = spi_setup(spi);
 359         if (ret)
 360                 goto out_m_can_class_free_dev;
 361
 362         ret = tcan4x5x_regmap_init(priv);
 363         if (ret)
 364                 goto out_m_can_class_free_dev;
 365
 366         ret = tcan4x5x_power_enable(priv->power, 1);
 367         if (ret)
 368                 goto out_m_can_class_free_dev;
 369
 370         ret = tcan4x5x_get_gpios(mcan_class);
 371         if (ret)
 372                 goto out_power;
 373
 374         ret = tcan4x5x_init(mcan_class);
 375         if (ret)
 376                 goto out_power;
 377
 378         ret = m_can_class_register(mcan_class);
 379         if (ret)
 380                 goto out_power;
 381
 382         netdev_info(mcan_class->net, "TCAN4X5X successfully initialized.\n");
 383         return 0;
 384
 385 out_power:
 386         tcan4x5x_power_enable(priv->power, 0);
 387  out_m_can_class_free_dev:
 388         m_can_class_free_dev(mcan_class->net);
 389         return ret;
 390 }
 391
 392 static int tcan4x5x_can_remove(struct spi_device *spi)
 393 {
 394         struct tcan4x5x_priv *priv = spi_get_drvdata(spi);
 395
 396         m_can_class_unregister(&priv->cdev);
 397
 398         tcan4x5x_power_enable(priv->power, 0);
 399
 400         m_can_class_free_dev(priv->cdev.net);
 401
 402         return 0;
 403 }
 404
 405 static const struct of_device_id tcan4x5x_of_match[] = {
 406         {
 407                 .compatible = "ti,tcan4x5x",
 408         }, {
 409                 /* sentinel */
 410         },
 411 };
 412 MODULE_DEVICE_TABLE(of, tcan4x5x_of_match);
 413
 414 static const struct spi_device_id tcan4x5x_id_table[] = {
 415         {
 416                 .name = "tcan4x5x",
 417         }, {
 418                 /* sentinel */
 419         },
 420 };
 421 MODULE_DEVICE_TABLE(spi, tcan4x5x_id_table);
 422
 423 static struct spi_driver tcan4x5x_can_driver = {
 424         .driver = {
 425                 .name = KBUILD_MODNAME,
 426                 .of_match_table = tcan4x5x_of_match,
 427                 .pm = NULL,
 428         },
 429         .id_table = tcan4x5x_id_table,
 430         .probe = tcan4x5x_can_probe,
 431         .remove = tcan4x5x_can_remove,
 432 };
 433 module_spi_driver(tcan4x5x_can_driver);
 434
 435 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
 436 MODULE_DESCRIPTION("Texas Instruments TCAN4x5x CAN driver");
 437 MODULE_LICENSE("GPL v2");