package/kernel/gpio-nct5104d/src/gpio-nct5104d.c

   1 /*
   2  * GPIO driver for NCT5104D
   3  *
   4  * Author: Tasanakorn Phaipool <tasanakorn@gmail.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/io.h>
  16 #include <linux/gpio.h>
  17 #include <linux/version.h>
  18 #include <linux/dmi.h>
  19 #include <linux/string.h>
  20
  21 #define DRVNAME "gpio-nct5104d"
  22
  23 /*
  24  * Super-I/O registers
  25  */
  26 #define SIO_LDSEL               0x07    /* Logical device select */
  27 #define SIO_CHIPID              0x20    /* Chaip ID (2 bytes) */
  28 #define SIO_GPIO_ENABLE 0x30    /* GPIO enable */
  29 #define SIO_GPIO1_MODE          0xE0    /* GPIO1 Mode OpenDrain/Push-Pull */
  30 #define SIO_GPIO2_MODE          0xE1    /* GPIO2 Mode OpenDrain/Push-Pull */
  31
  32 #define SIO_LD_GPIO             0x07    /* GPIO logical device */
  33 #define SIO_LD_GPIO_MODE        0x0F    /* GPIO mode control device */
  34 #define SIO_UNLOCK_KEY          0x87    /* Key to enable Super-I/O */
  35 #define SIO_LOCK_KEY            0xAA    /* Key to disable Super-I/O */
  36
  37 #define SIO_NCT5104D_ID                                 0x1061  /* Chip ID */
  38 #define SIO_PCENGINES_APU_NCT5104D_ID   0xc452  /* Chip ID */
  39
  40 enum chips { nct5104d };
  41
  42 static const char * const nct5104d_names[] = {
  43         "nct5104d"
  44 };
  45
  46 struct nct5104d_sio {
  47         int addr;
  48         enum chips type;
  49 };
  50
  51 struct nct5104d_gpio_bank {
  52         struct gpio_chip chip;
  53         unsigned int regbase;
  54         struct nct5104d_gpio_data *data;
  55 };
  56
  57 struct nct5104d_gpio_data {
  58         struct nct5104d_sio *sio;
  59         int nr_bank;
  60         struct nct5104d_gpio_bank *bank;
  61 };
  62
  63 /*
  64  * Super-I/O functions.
  65  */
  66
  67 static inline int superio_inb(int base, int reg)
  68 {
  69         outb(reg, base);
  70         return inb(base + 1);
  71 }
  72
  73 static int superio_inw(int base, int reg)
  74 {
  75         int val;
  76
  77         outb(reg++, base);
  78         val = inb(base + 1) << 8;
  79         outb(reg, base);
  80         val |= inb(base + 1);
  81
  82         return val;
  83 }
  84
  85 static inline void superio_outb(int base, int reg, int val)
  86 {
  87         outb(reg, base);
  88         outb(val, base + 1);
  89 }
  90
  91 static inline int superio_enter(int base)
  92 {
  93         /* Don't step on other drivers' I/O space by accident. */
  94         if (!request_muxed_region(base, 2, DRVNAME)) {
  95                 pr_err(DRVNAME "I/O address 0x%04x already in use\n", base);
  96                 return -EBUSY;
  97         }
  98
  99         /* According to the datasheet the key must be send twice. */
 100         outb(SIO_UNLOCK_KEY, base);
 101         outb(SIO_UNLOCK_KEY, base);
 102
 103         return 0;
 104 }
 105
 106 static inline void superio_select(int base, int ld)
 107 {
 108         outb(SIO_LDSEL, base);
 109         outb(ld, base + 1);
 110 }
 111
 112 static inline void superio_exit(int base)
 113 {
 114         outb(SIO_LOCK_KEY, base);
 115         release_region(base, 2);
 116 }
 117
 118 /*
 119  * GPIO chip.
 120  */
 121
 122 static int nct5104d_gpio_direction_in(struct gpio_chip *chip, unsigned offset);
 123 static int nct5104d_gpio_get(struct gpio_chip *chip, unsigned offset);
 124 static int nct5104d_gpio_direction_out(struct gpio_chip *chip,
 125                                      unsigned offset, int value);
 126 static void nct5104d_gpio_set(struct gpio_chip *chip, unsigned offset, int value);
 127
 128 #define NCT5104D_GPIO_BANK(_base, _ngpio, _regbase)                     \
 129         {                                                               \
 130                 .chip = {                                               \
 131                         .label            = DRVNAME,                    \
 132                         .owner            = THIS_MODULE,                \
 133                         .direction_input  = nct5104d_gpio_direction_in, \
 134                         .get              = nct5104d_gpio_get,          \
 135                         .direction_output = nct5104d_gpio_direction_out,        \
 136                         .set              = nct5104d_gpio_set,          \
 137                         .base             = _base,                      \
 138                         .ngpio            = _ngpio,                     \
 139                         .can_sleep        = true,                       \
 140                 },                                                      \
 141                 .regbase = _regbase,                                    \
 142         }
 143
 144 #define gpio_dir(base) (base + 0)
 145 #define gpio_data(base) (base + 1)
 146
 147 static struct nct5104d_gpio_bank nct5104d_gpio_bank[] = {
 148         NCT5104D_GPIO_BANK(0 , 8, 0xE0),
 149         NCT5104D_GPIO_BANK(10, 8, 0xE4)
 150 };
 151
 152 static int nct5104d_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
 153 {
 154         int err;
 155         struct nct5104d_gpio_bank *bank =
 156                 container_of(chip, struct nct5104d_gpio_bank, chip);
 157         struct nct5104d_sio *sio = bank->data->sio;
 158         u8 dir;
 159
 160         err = superio_enter(sio->addr);
 161         if (err)
 162                 return err;
 163         superio_select(sio->addr, SIO_LD_GPIO);
 164
 165         dir = superio_inb(sio->addr, gpio_dir(bank->regbase));
 166         dir |= (1 << offset);
 167         superio_outb(sio->addr, gpio_dir(bank->regbase), dir);
 168
 169         superio_exit(sio->addr);
 170
 171         return 0;
 172 }
 173
 174 static int nct5104d_gpio_get(struct gpio_chip *chip, unsigned offset)
 175 {
 176         int err;
 177         struct nct5104d_gpio_bank *bank =
 178                 container_of(chip, struct nct5104d_gpio_bank, chip);
 179         struct nct5104d_sio *sio = bank->data->sio;
 180         u8 data;
 181
 182         err = superio_enter(sio->addr);
 183         if (err)
 184                 return err;
 185         superio_select(sio->addr, SIO_LD_GPIO);
 186
 187         data = superio_inb(sio->addr, gpio_data(bank->regbase));
 188
 189         superio_exit(sio->addr);
 190
 191         return !!(data & 1 << offset);
 192 }
 193
 194 static int nct5104d_gpio_direction_out(struct gpio_chip *chip,
 195                                      unsigned offset, int value)
 196 {
 197         int err;
 198         struct nct5104d_gpio_bank *bank =
 199                 container_of(chip, struct nct5104d_gpio_bank, chip);
 200         struct nct5104d_sio *sio = bank->data->sio;
 201         u8 dir, data_out;
 202
 203         err = superio_enter(sio->addr);
 204         if (err)
 205                 return err;
 206         superio_select(sio->addr, SIO_LD_GPIO);
 207
 208         data_out = superio_inb(sio->addr, gpio_data(bank->regbase));
 209         if (value)
 210                 data_out |= (1 << offset);
 211         else
 212                 data_out &= ~(1 << offset);
 213         superio_outb(sio->addr, gpio_data(bank->regbase), data_out);
 214
 215         dir = superio_inb(sio->addr, gpio_dir(bank->regbase));
 216         dir &= ~(1 << offset);
 217         superio_outb(sio->addr, gpio_dir(bank->regbase), dir);
 218
 219         superio_exit(sio->addr);
 220
 221         return 0;
 222 }
 223
 224 static void nct5104d_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 225 {
 226         int err;
 227         struct nct5104d_gpio_bank *bank =
 228                 container_of(chip, struct nct5104d_gpio_bank, chip);
 229         struct nct5104d_sio *sio = bank->data->sio;
 230         u8 data_out;
 231
 232         err = superio_enter(sio->addr);
 233         if (err)
 234                 return;
 235         superio_select(sio->addr, SIO_LD_GPIO);
 236
 237         data_out = superio_inb(sio->addr, gpio_data(bank->regbase));
 238         if (value)
 239                 data_out |= (1 << offset);
 240         else
 241                 data_out &= ~(1 << offset);
 242         superio_outb(sio->addr, gpio_data(bank->regbase), data_out);
 243
 244         superio_exit(sio->addr);
 245 }
 246
 247 /*
 248  * Platform device and driver.
 249  */
 250
 251 static int nct5104d_gpio_probe(struct platform_device *pdev)
 252 {
 253         int err;
 254         int i;
 255         struct nct5104d_sio *sio = pdev->dev.platform_data;
 256         struct nct5104d_gpio_data *data;
 257
 258         data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
 259         if (!data)
 260                 return -ENOMEM;
 261
 262         switch (sio->type) {
 263         case nct5104d:
 264                 data->nr_bank = ARRAY_SIZE(nct5104d_gpio_bank);
 265                 data->bank = nct5104d_gpio_bank;
 266                 break;
 267         default:
 268                 return -ENODEV;
 269         }
 270         data->sio = sio;
 271
 272         platform_set_drvdata(pdev, data);
 273
 274         /* For each GPIO bank, register a GPIO chip. */
 275         for (i = 0; i < data->nr_bank; i++) {
 276                 struct nct5104d_gpio_bank *bank = &data->bank[i];
 277
 278 #if LINUX_VERSION_CODE < KERNEL_VERSION(4,5,0)
 279                 bank->chip.dev = &pdev->dev;
 280 #else
 281                 bank->chip.parent = &pdev->dev;
 282 #endif
 283                 bank->data = data;
 284
 285                 err = gpiochip_add(&bank->chip);
 286                 if (err) {
 287                         dev_err(&pdev->dev,
 288                                 "Failed to register gpiochip %d: %d\n",
 289                                 i, err);
 290                         goto err_gpiochip;
 291                 }
 292         }
 293
 294         return 0;
 295
 296 err_gpiochip:
 297         for (i = i - 1; i >= 0; i--) {
 298                 struct nct5104d_gpio_bank *bank = &data->bank[i];
 299
 300 #if LINUX_VERSION_CODE < KERNEL_VERSION(3,18,0)
 301                 int rm_err = gpiochip_remove(&bank->chip);
 302                 if (rm_err < 0)
 303                         dev_err(&pdev->dev,
 304                                 "Failed to remove gpiochip %d: %d\n",
 305                                 i, rm_err);
 306 #else /* LINUX_VERSION_CODE < KERNEL_VERSION(3,18,0) */
 307                 gpiochip_remove (&bank->chip);
 308 #endif /* LINUX_VERSION_CODE < KERNEL_VERSION(3,18,0) */
 309         }
 310
 311         return err;
 312 }
 313
 314 static int nct5104d_gpio_remove(struct platform_device *pdev)
 315 {
 316         int i;
 317         struct nct5104d_gpio_data *data = platform_get_drvdata(pdev);
 318
 319         for (i = 0; i < data->nr_bank; i++) {
 320                 struct nct5104d_gpio_bank *bank = &data->bank[i];
 321
 322 #if LINUX_VERSION_CODE < KERNEL_VERSION(3,18,0)
 323                 int err = gpiochip_remove(&bank->chip);
 324                 if (err) {
 325                         dev_err(&pdev->dev,
 326                                 "Failed to remove GPIO gpiochip %d: %d\n",
 327                                 i, err);
 328                         return err;
 329                 }
 330 #else /* LINUX_VERSION_CODE < KERNEL_VERSION(3,18,0) */
 331                 gpiochip_remove (&bank->chip);
 332 #endif /* LINUX_VERSION_CODE < KERNEL_VERSION(3,18,0) */
 333         }
 334
 335         return 0;
 336 }
 337
 338 static int __init nct5104d_find(int addr, struct nct5104d_sio *sio)
 339 {
 340         int err;
 341         u16 devid;
 342         u8 gpio_cfg;
 343
 344         err = superio_enter(addr);
 345         if (err)
 346                 return err;
 347
 348         err = -ENODEV;
 349
 350         devid = superio_inw(addr, SIO_CHIPID);
 351         switch (devid) {
 352         case SIO_NCT5104D_ID:
 353         case SIO_PCENGINES_APU_NCT5104D_ID:
 354                 sio->type = nct5104d;
 355                 /* enable GPIO0 and GPIO1 */
 356                 superio_select(addr, SIO_LD_GPIO);
 357                 gpio_cfg = superio_inb(addr, SIO_GPIO_ENABLE);
 358                 gpio_cfg |= 0x03;
 359                 superio_outb(addr, SIO_GPIO_ENABLE, gpio_cfg);
 360                 break;
 361         default:
 362                 pr_info(DRVNAME ": Unsupported device 0x%04x\n", devid);
 363                 goto err;
 364         }
 365         sio->addr = addr;
 366         err = 0;
 367
 368         pr_info(DRVNAME ": Found %s at %#x chip id 0x%04x\n",
 369                 nct5104d_names[sio->type],
 370                 (unsigned int) addr,
 371                 (int) superio_inw(addr, SIO_CHIPID));
 372
 373         superio_select(sio->addr, SIO_LD_GPIO_MODE);
 374         superio_outb(sio->addr, SIO_GPIO1_MODE, 0x0);
 375         superio_outb(sio->addr, SIO_GPIO2_MODE, 0x0);
 376
 377 err:
 378         superio_exit(addr);
 379         return err;
 380 }
 381
 382 static struct platform_device *nct5104d_gpio_pdev;
 383
 384 static int __init
 385 nct5104d_gpio_device_add(const struct nct5104d_sio *sio)
 386 {
 387         int err;
 388
 389         nct5104d_gpio_pdev = platform_device_alloc(DRVNAME, -1);
 390         if (!nct5104d_gpio_pdev)
 391                 pr_err(DRVNAME ": Error platform_device_alloc\n");
 392         if (!nct5104d_gpio_pdev)
 393                 return -ENOMEM;
 394
 395         err = platform_device_add_data(nct5104d_gpio_pdev,
 396                                        sio, sizeof(*sio));
 397         if (err) {
 398                 pr_err(DRVNAME "Platform data allocation failed\n");
 399                 goto err;
 400         }
 401
 402         err = platform_device_add(nct5104d_gpio_pdev);
 403         if (err) {
 404                 pr_err(DRVNAME "Device addition failed\n");
 405                 goto err;
 406         }
 407         pr_info(DRVNAME ": Device added\n");
 408         return 0;
 409
 410 err:
 411         platform_device_put(nct5104d_gpio_pdev);
 412
 413         return err;
 414 }
 415
 416 /*
 417  */
 418
 419 static struct platform_driver nct5104d_gpio_driver = {
 420         .driver = {
 421                 .owner  = THIS_MODULE,
 422                 .name   = DRVNAME,
 423         },
 424         .probe          = nct5104d_gpio_probe,
 425         .remove         = nct5104d_gpio_remove,
 426 };
 427
 428 static int __init nct5104d_gpio_init(void)
 429 {
 430         int err;
 431         struct nct5104d_sio sio;
 432         const char *board_vendor = dmi_get_system_info(DMI_BOARD_VENDOR);
 433         const char *board_name = dmi_get_system_info(DMI_BOARD_NAME);
 434
 435         /* Make sure we only run on PC Engine APU boards */
 436         if (!board_name || !board_vendor || strcasecmp(board_vendor, "PC Engines") || strncasecmp(board_name, "apu", 3)) {
 437                 return -ENODEV;
 438         }
 439
 440         if (nct5104d_find(0x2e, &sio) &&
 441             nct5104d_find(0x4e, &sio))
 442                 return -ENODEV;
 443
 444         err = platform_driver_register(&nct5104d_gpio_driver);
 445         if (!err) {
 446                 pr_info(DRVNAME ": platform_driver_register\n");
 447                 err = nct5104d_gpio_device_add(&sio);
 448                 if (err)
 449                         platform_driver_unregister(&nct5104d_gpio_driver);
 450         }
 451
 452         return err;
 453 }
 454 subsys_initcall(nct5104d_gpio_init);
 455
 456 static void __exit nct5104d_gpio_exit(void)
 457 {
 458         platform_device_unregister(nct5104d_gpio_pdev);
 459         platform_driver_unregister(&nct5104d_gpio_driver);
 460 }
 461 module_exit(nct5104d_gpio_exit);
 462
 463 MODULE_DESCRIPTION("GPIO driver for Super-I/O chips NCT5104D");
 464 MODULE_AUTHOR("Tasanakorn Phaipool <tasanakorn@gmail.com>");
 465 MODULE_LICENSE("GPL");