drivers/gpio/gpio-viperboard.c

   1 /*
   2  *  Nano River Technologies viperboard GPIO lib driver
   3  *
   4  *  (C) 2012 by Lemonage GmbH
   5  *  Author: Lars Poeschel <poeschel@lemonage.de>
   6  *  All rights reserved.
   7  *
   8  *  This program is free software; you can redistribute  it and/or modify it
   9  *  under  the terms of  the GNU General  Public License as published by the
  10  *  Free Software Foundation;  either version 2 of the  License, or (at your
  11  *  option) any later version.
  12  *
  13  */
  14
  15 #include <linux/kernel.h>
  16 #include <linux/errno.h>
  17 #include <linux/module.h>
  18 #include <linux/slab.h>
  19 #include <linux/types.h>
  20 #include <linux/mutex.h>
  21 #include <linux/platform_device.h>
  22
  23 #include <linux/usb.h>
  24 #include <linux/gpio.h>
  25
  26 #include <linux/mfd/viperboard.h>
  27
  28 #define VPRBRD_GPIOA_CLK_1MHZ           0
  29 #define VPRBRD_GPIOA_CLK_100KHZ         1
  30 #define VPRBRD_GPIOA_CLK_10KHZ          2
  31 #define VPRBRD_GPIOA_CLK_1KHZ           3
  32 #define VPRBRD_GPIOA_CLK_100HZ          4
  33 #define VPRBRD_GPIOA_CLK_10HZ           5
  34
  35 #define VPRBRD_GPIOA_FREQ_DEFAULT       1000
  36
  37 #define VPRBRD_GPIOA_CMD_CONT           0x00
  38 #define VPRBRD_GPIOA_CMD_PULSE          0x01
  39 #define VPRBRD_GPIOA_CMD_PWM            0x02
  40 #define VPRBRD_GPIOA_CMD_SETOUT         0x03
  41 #define VPRBRD_GPIOA_CMD_SETIN          0x04
  42 #define VPRBRD_GPIOA_CMD_SETINT         0x05
  43 #define VPRBRD_GPIOA_CMD_GETIN          0x06
  44
  45 #define VPRBRD_GPIOB_CMD_SETDIR         0x00
  46 #define VPRBRD_GPIOB_CMD_SETVAL         0x01
  47
  48 struct vprbrd_gpioa_msg {
  49         u8 cmd;
  50         u8 clk;
  51         u8 offset;
  52         u8 t1;
  53         u8 t2;
  54         u8 invert;
  55         u8 pwmlevel;
  56         u8 outval;
  57         u8 risefall;
  58         u8 answer;
  59         u8 __fill;
  60 } __packed;
  61
  62 struct vprbrd_gpiob_msg {
  63         u8 cmd;
  64         u16 val;
  65         u16 mask;
  66 } __packed;
  67
  68 struct vprbrd_gpio {
  69         struct gpio_chip gpioa; /* gpio a related things */
  70         u32 gpioa_out;
  71         u32 gpioa_val;
  72         struct gpio_chip gpiob; /* gpio b related things */
  73         u32 gpiob_out;
  74         u32 gpiob_val;
  75         struct vprbrd *vb;
  76 };
  77
  78 /* gpioa sampling clock module parameter */
  79 static unsigned char gpioa_clk;
  80 static unsigned int gpioa_freq = VPRBRD_GPIOA_FREQ_DEFAULT;
  81 module_param(gpioa_freq, uint, 0);
  82 MODULE_PARM_DESC(gpioa_freq,
  83         "gpio-a sampling freq in Hz (default is 1000Hz) valid values: 10, 100, 1000, 10000, 100000, 1000000");
  84
  85 /* ----- begin of gipo a chip -------------------------------------------- */
  86
  87 static int vprbrd_gpioa_get(struct gpio_chip *chip,
  88                 unsigned offset)
  89 {
  90         int ret, answer, error = 0;
  91         struct vprbrd_gpio *gpio =
  92                         container_of(chip, struct vprbrd_gpio, gpioa);
  93         struct vprbrd *vb = gpio->vb;
  94         struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
  95
  96         /* if io is set to output, just return the saved value */
  97         if (gpio->gpioa_out & (1 << offset))
  98                 return gpio->gpioa_val & (1 << offset);
  99
 100         mutex_lock(&vb->lock);
 101
 102         gamsg->cmd = VPRBRD_GPIOA_CMD_GETIN;
 103         gamsg->clk = 0x00;
 104         gamsg->offset = offset;
 105         gamsg->t1 = 0x00;
 106         gamsg->t2 = 0x00;
 107         gamsg->invert = 0x00;
 108         gamsg->pwmlevel = 0x00;
 109         gamsg->outval = 0x00;
 110         gamsg->risefall = 0x00;
 111         gamsg->answer = 0x00;
 112         gamsg->__fill = 0x00;
 113
 114         ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
 115                 VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
 116                 0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
 117                 VPRBRD_USB_TIMEOUT_MS);
 118         if (ret != sizeof(struct vprbrd_gpioa_msg))
 119                 error = -EREMOTEIO;
 120
 121         ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
 122                 VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_IN, 0x0000,
 123                 0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
 124                 VPRBRD_USB_TIMEOUT_MS);
 125         answer = gamsg->answer & 0x01;
 126
 127         mutex_unlock(&vb->lock);
 128
 129         if (ret != sizeof(struct vprbrd_gpioa_msg))
 130                 error = -EREMOTEIO;
 131
 132         if (error)
 133                 return error;
 134
 135         return answer;
 136 }
 137
 138 static void vprbrd_gpioa_set(struct gpio_chip *chip,
 139                 unsigned offset, int value)
 140 {
 141         int ret;
 142         struct vprbrd_gpio *gpio =
 143                         container_of(chip, struct vprbrd_gpio, gpioa);
 144         struct vprbrd *vb = gpio->vb;
 145         struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
 146
 147         if (gpio->gpioa_out & (1 << offset)) {
 148                 if (value)
 149                         gpio->gpioa_val |= (1 << offset);
 150                 else
 151                         gpio->gpioa_val &= ~(1 << offset);
 152
 153                 mutex_lock(&vb->lock);
 154
 155                 gamsg->cmd = VPRBRD_GPIOA_CMD_SETOUT;
 156                 gamsg->clk = 0x00;
 157                 gamsg->offset = offset;
 158                 gamsg->t1 = 0x00;
 159                 gamsg->t2 = 0x00;
 160                 gamsg->invert = 0x00;
 161                 gamsg->pwmlevel = 0x00;
 162                 gamsg->outval = value;
 163                 gamsg->risefall = 0x00;
 164                 gamsg->answer = 0x00;
 165                 gamsg->__fill = 0x00;
 166
 167                 ret = usb_control_msg(vb->usb_dev,
 168                         usb_sndctrlpipe(vb->usb_dev, 0),
 169                         VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT,
 170                         0x0000, 0x0000, gamsg,
 171                         sizeof(struct vprbrd_gpioa_msg), VPRBRD_USB_TIMEOUT_MS);
 172
 173                 mutex_unlock(&vb->lock);
 174
 175                 if (ret != sizeof(struct vprbrd_gpioa_msg))
 176                         dev_err(chip->dev, "usb error setting pin value\n");
 177         }
 178 }
 179
 180 static int vprbrd_gpioa_direction_input(struct gpio_chip *chip,
 181                         unsigned offset)
 182 {
 183         int ret;
 184         struct vprbrd_gpio *gpio =
 185                         container_of(chip, struct vprbrd_gpio, gpioa);
 186         struct vprbrd *vb = gpio->vb;
 187         struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
 188
 189         gpio->gpioa_out &= ~(1 << offset);
 190
 191         mutex_lock(&vb->lock);
 192
 193         gamsg->cmd = VPRBRD_GPIOA_CMD_SETIN;
 194         gamsg->clk = gpioa_clk;
 195         gamsg->offset = offset;
 196         gamsg->t1 = 0x00;
 197         gamsg->t2 = 0x00;
 198         gamsg->invert = 0x00;
 199         gamsg->pwmlevel = 0x00;
 200         gamsg->outval = 0x00;
 201         gamsg->risefall = 0x00;
 202         gamsg->answer = 0x00;
 203         gamsg->__fill = 0x00;
 204
 205         ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
 206                 VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
 207                 0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
 208                 VPRBRD_USB_TIMEOUT_MS);
 209
 210         mutex_unlock(&vb->lock);
 211
 212         if (ret != sizeof(struct vprbrd_gpioa_msg))
 213                 return -EREMOTEIO;
 214
 215         return 0;
 216 }
 217
 218 static int vprbrd_gpioa_direction_output(struct gpio_chip *chip,
 219                         unsigned offset, int value)
 220 {
 221         int ret;
 222         struct vprbrd_gpio *gpio =
 223                         container_of(chip, struct vprbrd_gpio, gpioa);
 224         struct vprbrd *vb = gpio->vb;
 225         struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
 226
 227         gpio->gpioa_out |= (1 << offset);
 228         if (value)
 229                 gpio->gpioa_val |= (1 << offset);
 230         else
 231                 gpio->gpioa_val &= ~(1 << offset);
 232
 233         mutex_lock(&vb->lock);
 234
 235         gamsg->cmd = VPRBRD_GPIOA_CMD_SETOUT;
 236         gamsg->clk = 0x00;
 237         gamsg->offset = offset;
 238         gamsg->t1 = 0x00;
 239         gamsg->t2 = 0x00;
 240         gamsg->invert = 0x00;
 241         gamsg->pwmlevel = 0x00;
 242         gamsg->outval = value;
 243         gamsg->risefall = 0x00;
 244         gamsg->answer = 0x00;
 245         gamsg->__fill = 0x00;
 246
 247         ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
 248                 VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
 249                 0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
 250                 VPRBRD_USB_TIMEOUT_MS);
 251
 252         mutex_unlock(&vb->lock);
 253
 254         if (ret != sizeof(struct vprbrd_gpioa_msg))
 255                 return -EREMOTEIO;
 256
 257         return 0;
 258 }
 259
 260 /* ----- end of gpio a chip ---------------------------------------------- */
 261
 262 /* ----- begin of gipo b chip -------------------------------------------- */
 263
 264 static int vprbrd_gpiob_setdir(struct vprbrd *vb, unsigned offset,
 265         unsigned dir)
 266 {
 267         struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;
 268         int ret;
 269
 270         gbmsg->cmd = VPRBRD_GPIOB_CMD_SETDIR;
 271         gbmsg->val = cpu_to_be16(dir << offset);
 272         gbmsg->mask = cpu_to_be16(0x0001 << offset);
 273
 274         ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
 275                 VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_OUT, 0x0000,
 276                 0x0000, gbmsg, sizeof(struct vprbrd_gpiob_msg),
 277                 VPRBRD_USB_TIMEOUT_MS);
 278
 279         if (ret != sizeof(struct vprbrd_gpiob_msg))
 280                 return -EREMOTEIO;
 281
 282         return 0;
 283 }
 284
 285 static int vprbrd_gpiob_get(struct gpio_chip *chip,
 286                 unsigned offset)
 287 {
 288         int ret;
 289         u16 val;
 290         struct vprbrd_gpio *gpio =
 291                         container_of(chip, struct vprbrd_gpio, gpiob);
 292         struct vprbrd *vb = gpio->vb;
 293         struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;
 294
 295         /* if io is set to output, just return the saved value */
 296         if (gpio->gpiob_out & (1 << offset))
 297                 return gpio->gpiob_val & (1 << offset);
 298
 299         mutex_lock(&vb->lock);
 300
 301         ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
 302                 VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_IN, 0x0000,
 303                 0x0000, gbmsg,  sizeof(struct vprbrd_gpiob_msg),
 304                 VPRBRD_USB_TIMEOUT_MS);
 305         val = gbmsg->val;
 306
 307         mutex_unlock(&vb->lock);
 308
 309         if (ret != sizeof(struct vprbrd_gpiob_msg))
 310                 return ret;
 311
 312         /* cache the read values */
 313         gpio->gpiob_val = be16_to_cpu(val);
 314
 315         return (gpio->gpiob_val >> offset) & 0x1;
 316 }
 317
 318 static void vprbrd_gpiob_set(struct gpio_chip *chip,
 319                 unsigned offset, int value)
 320 {
 321         int ret;
 322         struct vprbrd_gpio *gpio =
 323                         container_of(chip, struct vprbrd_gpio, gpiob);
 324         struct vprbrd *vb = gpio->vb;
 325         struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;
 326
 327         if (gpio->gpiob_out & (1 << offset)) {
 328                 if (value)
 329                         gpio->gpiob_val |= (1 << offset);
 330                 else
 331                         gpio->gpiob_val &= ~(1 << offset);
 332
 333                 mutex_lock(&vb->lock);
 334
 335                 gbmsg->cmd = VPRBRD_GPIOB_CMD_SETVAL;
 336                 gbmsg->val = cpu_to_be16(value << offset);
 337                 gbmsg->mask = cpu_to_be16(0x0001 << offset);
 338
 339                 ret = usb_control_msg(vb->usb_dev,
 340                         usb_sndctrlpipe(vb->usb_dev, 0),
 341                         VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_OUT,
 342                         0x0000, 0x0000, gbmsg,
 343                         sizeof(struct vprbrd_gpiob_msg), VPRBRD_USB_TIMEOUT_MS);
 344
 345                 mutex_unlock(&vb->lock);
 346
 347                 if (ret != sizeof(struct vprbrd_gpiob_msg))
 348                         dev_err(chip->dev, "usb error setting pin value\n");
 349         }
 350 }
 351
 352 static int vprbrd_gpiob_direction_input(struct gpio_chip *chip,
 353                         unsigned offset)
 354 {
 355         int ret;
 356         struct vprbrd_gpio *gpio =
 357                         container_of(chip, struct vprbrd_gpio, gpiob);
 358         struct vprbrd *vb = gpio->vb;
 359
 360         gpio->gpiob_out &= ~(1 << offset);
 361
 362         mutex_lock(&vb->lock);
 363
 364         ret = vprbrd_gpiob_setdir(vb, offset, 0);
 365
 366         mutex_unlock(&vb->lock);
 367
 368         if (ret)
 369                 dev_err(chip->dev, "usb error setting pin to input\n");
 370
 371         return ret;
 372 }
 373
 374 static int vprbrd_gpiob_direction_output(struct gpio_chip *chip,
 375                         unsigned offset, int value)
 376 {
 377         int ret;
 378         struct vprbrd_gpio *gpio =
 379                         container_of(chip, struct vprbrd_gpio, gpiob);
 380         struct vprbrd *vb = gpio->vb;
 381
 382         gpio->gpiob_out |= (1 << offset);
 383
 384         mutex_lock(&vb->lock);
 385
 386         ret = vprbrd_gpiob_setdir(vb, offset, 1);
 387         if (ret)
 388                 dev_err(chip->dev, "usb error setting pin to output\n");
 389
 390         mutex_unlock(&vb->lock);
 391
 392         vprbrd_gpiob_set(chip, offset, value);
 393
 394         return ret;
 395 }
 396
 397 /* ----- end of gpio b chip ---------------------------------------------- */
 398
 399 static int vprbrd_gpio_probe(struct platform_device *pdev)
 400 {
 401         struct vprbrd *vb = dev_get_drvdata(pdev->dev.parent);
 402         struct vprbrd_gpio *vb_gpio;
 403         int ret;
 404
 405         vb_gpio = devm_kzalloc(&pdev->dev, sizeof(*vb_gpio), GFP_KERNEL);
 406         if (vb_gpio == NULL)
 407                 return -ENOMEM;
 408
 409         vb_gpio->vb = vb;
 410         /* registering gpio a */
 411         vb_gpio->gpioa.label = "viperboard gpio a";
 412         vb_gpio->gpioa.dev = &pdev->dev;
 413         vb_gpio->gpioa.owner = THIS_MODULE;
 414         vb_gpio->gpioa.base = -1;
 415         vb_gpio->gpioa.ngpio = 16;
 416         vb_gpio->gpioa.can_sleep = 1;
 417         vb_gpio->gpioa.set = vprbrd_gpioa_set;
 418         vb_gpio->gpioa.get = vprbrd_gpioa_get;
 419         vb_gpio->gpioa.direction_input = vprbrd_gpioa_direction_input;
 420         vb_gpio->gpioa.direction_output = vprbrd_gpioa_direction_output;
 421         ret = gpiochip_add(&vb_gpio->gpioa);
 422         if (ret < 0) {
 423                 dev_err(vb_gpio->gpioa.dev, "could not add gpio a");
 424                 goto err_gpioa;
 425         }
 426
 427         /* registering gpio b */
 428         vb_gpio->gpiob.label = "viperboard gpio b";
 429         vb_gpio->gpiob.dev = &pdev->dev;
 430         vb_gpio->gpiob.owner = THIS_MODULE;
 431         vb_gpio->gpiob.base = -1;
 432         vb_gpio->gpiob.ngpio = 16;
 433         vb_gpio->gpiob.can_sleep = 1;
 434         vb_gpio->gpiob.set = vprbrd_gpiob_set;
 435         vb_gpio->gpiob.get = vprbrd_gpiob_get;
 436         vb_gpio->gpiob.direction_input = vprbrd_gpiob_direction_input;
 437         vb_gpio->gpiob.direction_output = vprbrd_gpiob_direction_output;
 438         ret = gpiochip_add(&vb_gpio->gpiob);
 439         if (ret < 0) {
 440                 dev_err(vb_gpio->gpiob.dev, "could not add gpio b");
 441                 goto err_gpiob;
 442         }
 443
 444         platform_set_drvdata(pdev, vb_gpio);
 445
 446         return ret;
 447
 448 err_gpiob:
 449         if (gpiochip_remove(&vb_gpio->gpioa))
 450                 dev_err(&pdev->dev, "%s gpiochip_remove failed\n", __func__);
 451
 452 err_gpioa:
 453         return ret;
 454 }
 455
 456 static int vprbrd_gpio_remove(struct platform_device *pdev)
 457 {
 458         struct vprbrd_gpio *vb_gpio = platform_get_drvdata(pdev);
 459         int ret;
 460
 461         ret = gpiochip_remove(&vb_gpio->gpiob);
 462         if (ret == 0)
 463                 ret = gpiochip_remove(&vb_gpio->gpioa);
 464
 465         return ret;
 466 }
 467
 468 static struct platform_driver vprbrd_gpio_driver = {
 469         .driver.name    = "viperboard-gpio",
 470         .driver.owner   = THIS_MODULE,
 471         .probe          = vprbrd_gpio_probe,
 472         .remove         = vprbrd_gpio_remove,
 473 };
 474
 475 static int __init vprbrd_gpio_init(void)
 476 {
 477         switch (gpioa_freq) {
 478         case 1000000:
 479                 gpioa_clk = VPRBRD_GPIOA_CLK_1MHZ;
 480                 break;
 481         case 100000:
 482                 gpioa_clk = VPRBRD_GPIOA_CLK_100KHZ;
 483                 break;
 484         case 10000:
 485                 gpioa_clk = VPRBRD_GPIOA_CLK_10KHZ;
 486                 break;
 487         case 1000:
 488                 gpioa_clk = VPRBRD_GPIOA_CLK_1KHZ;
 489                 break;
 490         case 100:
 491                 gpioa_clk = VPRBRD_GPIOA_CLK_100HZ;
 492                 break;
 493         case 10:
 494                 gpioa_clk = VPRBRD_GPIOA_CLK_10HZ;
 495                 break;
 496         default:
 497                 pr_warn("invalid gpioa_freq (%d)\n", gpioa_freq);
 498                 gpioa_clk = VPRBRD_GPIOA_CLK_1KHZ;
 499         }
 500
 501         return platform_driver_register(&vprbrd_gpio_driver);
 502 }
 503 subsys_initcall(vprbrd_gpio_init);
 504
 505 static void __exit vprbrd_gpio_exit(void)
 506 {
 507         platform_driver_unregister(&vprbrd_gpio_driver);
 508 }
 509 module_exit(vprbrd_gpio_exit);
 510
 511 MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
 512 MODULE_DESCRIPTION("GPIO driver for Nano River Techs Viperboard");
 513 MODULE_LICENSE("GPL");
 514 MODULE_ALIAS("platform:viperboard-gpio");