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 = gpiochip_get_data(chip);
  92         struct vprbrd *vb = gpio->vb;
  93         struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
  94
  95         /* if io is set to output, just return the saved value */
  96         if (gpio->gpioa_out & (1 << offset))
  97                 return !!(gpio->gpioa_val & (1 << offset));
  98
  99         mutex_lock(&vb->lock);
 100
 101         gamsg->cmd = VPRBRD_GPIOA_CMD_GETIN;
 102         gamsg->clk = 0x00;
 103         gamsg->offset = offset;
 104         gamsg->t1 = 0x00;
 105         gamsg->t2 = 0x00;
 106         gamsg->invert = 0x00;
 107         gamsg->pwmlevel = 0x00;
 108         gamsg->outval = 0x00;
 109         gamsg->risefall = 0x00;
 110         gamsg->answer = 0x00;
 111         gamsg->__fill = 0x00;
 112
 113         ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
 114                 VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
 115                 0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
 116                 VPRBRD_USB_TIMEOUT_MS);
 117         if (ret != sizeof(struct vprbrd_gpioa_msg))
 118                 error = -EREMOTEIO;
 119
 120         ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
 121                 VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_IN, 0x0000,
 122                 0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
 123                 VPRBRD_USB_TIMEOUT_MS);
 124         answer = gamsg->answer & 0x01;
 125
 126         mutex_unlock(&vb->lock);
 127
 128         if (ret != sizeof(struct vprbrd_gpioa_msg))
 129                 error = -EREMOTEIO;
 130
 131         if (error)
 132                 return error;
 133
 134         return answer;
 135 }
 136
 137 static void vprbrd_gpioa_set(struct gpio_chip *chip,
 138                 unsigned offset, int value)
 139 {
 140         int ret;
 141         struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
 142         struct vprbrd *vb = gpio->vb;
 143         struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
 144
 145         if (gpio->gpioa_out & (1 << offset)) {
 146                 if (value)
 147                         gpio->gpioa_val |= (1 << offset);
 148                 else
 149                         gpio->gpioa_val &= ~(1 << offset);
 150
 151                 mutex_lock(&vb->lock);
 152
 153                 gamsg->cmd = VPRBRD_GPIOA_CMD_SETOUT;
 154                 gamsg->clk = 0x00;
 155                 gamsg->offset = offset;
 156                 gamsg->t1 = 0x00;
 157                 gamsg->t2 = 0x00;
 158                 gamsg->invert = 0x00;
 159                 gamsg->pwmlevel = 0x00;
 160                 gamsg->outval = value;
 161                 gamsg->risefall = 0x00;
 162                 gamsg->answer = 0x00;
 163                 gamsg->__fill = 0x00;
 164
 165                 ret = usb_control_msg(vb->usb_dev,
 166                         usb_sndctrlpipe(vb->usb_dev, 0),
 167                         VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT,
 168                         0x0000, 0x0000, gamsg,
 169                         sizeof(struct vprbrd_gpioa_msg), VPRBRD_USB_TIMEOUT_MS);
 170
 171                 mutex_unlock(&vb->lock);
 172
 173                 if (ret != sizeof(struct vprbrd_gpioa_msg))
 174                         dev_err(chip->parent, "usb error setting pin value\n");
 175         }
 176 }
 177
 178 static int vprbrd_gpioa_direction_input(struct gpio_chip *chip,
 179                         unsigned offset)
 180 {
 181         int ret;
 182         struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
 183         struct vprbrd *vb = gpio->vb;
 184         struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
 185
 186         gpio->gpioa_out &= ~(1 << offset);
 187
 188         mutex_lock(&vb->lock);
 189
 190         gamsg->cmd = VPRBRD_GPIOA_CMD_SETIN;
 191         gamsg->clk = gpioa_clk;
 192         gamsg->offset = offset;
 193         gamsg->t1 = 0x00;
 194         gamsg->t2 = 0x00;
 195         gamsg->invert = 0x00;
 196         gamsg->pwmlevel = 0x00;
 197         gamsg->outval = 0x00;
 198         gamsg->risefall = 0x00;
 199         gamsg->answer = 0x00;
 200         gamsg->__fill = 0x00;
 201
 202         ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
 203                 VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
 204                 0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
 205                 VPRBRD_USB_TIMEOUT_MS);
 206
 207         mutex_unlock(&vb->lock);
 208
 209         if (ret != sizeof(struct vprbrd_gpioa_msg))
 210                 return -EREMOTEIO;
 211
 212         return 0;
 213 }
 214
 215 static int vprbrd_gpioa_direction_output(struct gpio_chip *chip,
 216                         unsigned offset, int value)
 217 {
 218         int ret;
 219         struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
 220         struct vprbrd *vb = gpio->vb;
 221         struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
 222
 223         gpio->gpioa_out |= (1 << offset);
 224         if (value)
 225                 gpio->gpioa_val |= (1 << offset);
 226         else
 227                 gpio->gpioa_val &= ~(1 << offset);
 228
 229         mutex_lock(&vb->lock);
 230
 231         gamsg->cmd = VPRBRD_GPIOA_CMD_SETOUT;
 232         gamsg->clk = 0x00;
 233         gamsg->offset = offset;
 234         gamsg->t1 = 0x00;
 235         gamsg->t2 = 0x00;
 236         gamsg->invert = 0x00;
 237         gamsg->pwmlevel = 0x00;
 238         gamsg->outval = value;
 239         gamsg->risefall = 0x00;
 240         gamsg->answer = 0x00;
 241         gamsg->__fill = 0x00;
 242
 243         ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
 244                 VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
 245                 0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
 246                 VPRBRD_USB_TIMEOUT_MS);
 247
 248         mutex_unlock(&vb->lock);
 249
 250         if (ret != sizeof(struct vprbrd_gpioa_msg))
 251                 return -EREMOTEIO;
 252
 253         return 0;
 254 }
 255
 256 /* ----- end of gpio a chip ---------------------------------------------- */
 257
 258 /* ----- begin of gipo b chip -------------------------------------------- */
 259
 260 static int vprbrd_gpiob_setdir(struct vprbrd *vb, unsigned offset,
 261         unsigned dir)
 262 {
 263         struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;
 264         int ret;
 265
 266         gbmsg->cmd = VPRBRD_GPIOB_CMD_SETDIR;
 267         gbmsg->val = cpu_to_be16(dir << offset);
 268         gbmsg->mask = cpu_to_be16(0x0001 << offset);
 269
 270         ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
 271                 VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_OUT, 0x0000,
 272                 0x0000, gbmsg, sizeof(struct vprbrd_gpiob_msg),
 273                 VPRBRD_USB_TIMEOUT_MS);
 274
 275         if (ret != sizeof(struct vprbrd_gpiob_msg))
 276                 return -EREMOTEIO;
 277
 278         return 0;
 279 }
 280
 281 static int vprbrd_gpiob_get(struct gpio_chip *chip,
 282                 unsigned offset)
 283 {
 284         int ret;
 285         u16 val;
 286         struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
 287         struct vprbrd *vb = gpio->vb;
 288         struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;
 289
 290         /* if io is set to output, just return the saved value */
 291         if (gpio->gpiob_out & (1 << offset))
 292                 return gpio->gpiob_val & (1 << offset);
 293
 294         mutex_lock(&vb->lock);
 295
 296         ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
 297                 VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_IN, 0x0000,
 298                 0x0000, gbmsg,  sizeof(struct vprbrd_gpiob_msg),
 299                 VPRBRD_USB_TIMEOUT_MS);
 300         val = gbmsg->val;
 301
 302         mutex_unlock(&vb->lock);
 303
 304         if (ret != sizeof(struct vprbrd_gpiob_msg))
 305                 return ret;
 306
 307         /* cache the read values */
 308         gpio->gpiob_val = be16_to_cpu(val);
 309
 310         return (gpio->gpiob_val >> offset) & 0x1;
 311 }
 312
 313 static void vprbrd_gpiob_set(struct gpio_chip *chip,
 314                 unsigned offset, int value)
 315 {
 316         int ret;
 317         struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
 318         struct vprbrd *vb = gpio->vb;
 319         struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;
 320
 321         if (gpio->gpiob_out & (1 << offset)) {
 322                 if (value)
 323                         gpio->gpiob_val |= (1 << offset);
 324                 else
 325                         gpio->gpiob_val &= ~(1 << offset);
 326
 327                 mutex_lock(&vb->lock);
 328
 329                 gbmsg->cmd = VPRBRD_GPIOB_CMD_SETVAL;
 330                 gbmsg->val = cpu_to_be16(value << offset);
 331                 gbmsg->mask = cpu_to_be16(0x0001 << offset);
 332
 333                 ret = usb_control_msg(vb->usb_dev,
 334                         usb_sndctrlpipe(vb->usb_dev, 0),
 335                         VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_OUT,
 336                         0x0000, 0x0000, gbmsg,
 337                         sizeof(struct vprbrd_gpiob_msg), VPRBRD_USB_TIMEOUT_MS);
 338
 339                 mutex_unlock(&vb->lock);
 340
 341                 if (ret != sizeof(struct vprbrd_gpiob_msg))
 342                         dev_err(chip->parent, "usb error setting pin value\n");
 343         }
 344 }
 345
 346 static int vprbrd_gpiob_direction_input(struct gpio_chip *chip,
 347                         unsigned offset)
 348 {
 349         int ret;
 350         struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
 351         struct vprbrd *vb = gpio->vb;
 352
 353         gpio->gpiob_out &= ~(1 << offset);
 354
 355         mutex_lock(&vb->lock);
 356
 357         ret = vprbrd_gpiob_setdir(vb, offset, 0);
 358
 359         mutex_unlock(&vb->lock);
 360
 361         if (ret)
 362                 dev_err(chip->parent, "usb error setting pin to input\n");
 363
 364         return ret;
 365 }
 366
 367 static int vprbrd_gpiob_direction_output(struct gpio_chip *chip,
 368                         unsigned offset, int value)
 369 {
 370         int ret;
 371         struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
 372         struct vprbrd *vb = gpio->vb;
 373
 374         gpio->gpiob_out |= (1 << offset);
 375
 376         mutex_lock(&vb->lock);
 377
 378         ret = vprbrd_gpiob_setdir(vb, offset, 1);
 379         if (ret)
 380                 dev_err(chip->parent, "usb error setting pin to output\n");
 381
 382         mutex_unlock(&vb->lock);
 383
 384         vprbrd_gpiob_set(chip, offset, value);
 385
 386         return ret;
 387 }
 388
 389 /* ----- end of gpio b chip ---------------------------------------------- */
 390
 391 static int vprbrd_gpio_probe(struct platform_device *pdev)
 392 {
 393         struct vprbrd *vb = dev_get_drvdata(pdev->dev.parent);
 394         struct vprbrd_gpio *vb_gpio;
 395         int ret;
 396
 397         vb_gpio = devm_kzalloc(&pdev->dev, sizeof(*vb_gpio), GFP_KERNEL);
 398         if (vb_gpio == NULL)
 399                 return -ENOMEM;
 400
 401         vb_gpio->vb = vb;
 402         /* registering gpio a */
 403         vb_gpio->gpioa.label = "viperboard gpio a";
 404         vb_gpio->gpioa.parent = &pdev->dev;
 405         vb_gpio->gpioa.owner = THIS_MODULE;
 406         vb_gpio->gpioa.base = -1;
 407         vb_gpio->gpioa.ngpio = 16;
 408         vb_gpio->gpioa.can_sleep = true;
 409         vb_gpio->gpioa.set = vprbrd_gpioa_set;
 410         vb_gpio->gpioa.get = vprbrd_gpioa_get;
 411         vb_gpio->gpioa.direction_input = vprbrd_gpioa_direction_input;
 412         vb_gpio->gpioa.direction_output = vprbrd_gpioa_direction_output;
 413         ret = devm_gpiochip_add_data(&pdev->dev, &vb_gpio->gpioa, vb_gpio);
 414         if (ret < 0) {
 415                 dev_err(vb_gpio->gpioa.parent, "could not add gpio a");
 416                 return ret;
 417         }
 418
 419         /* registering gpio b */
 420         vb_gpio->gpiob.label = "viperboard gpio b";
 421         vb_gpio->gpiob.parent = &pdev->dev;
 422         vb_gpio->gpiob.owner = THIS_MODULE;
 423         vb_gpio->gpiob.base = -1;
 424         vb_gpio->gpiob.ngpio = 16;
 425         vb_gpio->gpiob.can_sleep = true;
 426         vb_gpio->gpiob.set = vprbrd_gpiob_set;
 427         vb_gpio->gpiob.get = vprbrd_gpiob_get;
 428         vb_gpio->gpiob.direction_input = vprbrd_gpiob_direction_input;
 429         vb_gpio->gpiob.direction_output = vprbrd_gpiob_direction_output;
 430         ret = devm_gpiochip_add_data(&pdev->dev, &vb_gpio->gpiob, vb_gpio);
 431         if (ret < 0) {
 432                 dev_err(vb_gpio->gpiob.parent, "could not add gpio b");
 433                 return ret;
 434         }
 435
 436         platform_set_drvdata(pdev, vb_gpio);
 437
 438         return ret;
 439 }
 440
 441 static struct platform_driver vprbrd_gpio_driver = {
 442         .driver.name    = "viperboard-gpio",
 443         .probe          = vprbrd_gpio_probe,
 444 };
 445
 446 static int __init vprbrd_gpio_init(void)
 447 {
 448         switch (gpioa_freq) {
 449         case 1000000:
 450                 gpioa_clk = VPRBRD_GPIOA_CLK_1MHZ;
 451                 break;
 452         case 100000:
 453                 gpioa_clk = VPRBRD_GPIOA_CLK_100KHZ;
 454                 break;
 455         case 10000:
 456                 gpioa_clk = VPRBRD_GPIOA_CLK_10KHZ;
 457                 break;
 458         case 1000:
 459                 gpioa_clk = VPRBRD_GPIOA_CLK_1KHZ;
 460                 break;
 461         case 100:
 462                 gpioa_clk = VPRBRD_GPIOA_CLK_100HZ;
 463                 break;
 464         case 10:
 465                 gpioa_clk = VPRBRD_GPIOA_CLK_10HZ;
 466                 break;
 467         default:
 468                 pr_warn("invalid gpioa_freq (%d)\n", gpioa_freq);
 469                 gpioa_clk = VPRBRD_GPIOA_CLK_1KHZ;
 470         }
 471
 472         return platform_driver_register(&vprbrd_gpio_driver);
 473 }
 474 subsys_initcall(vprbrd_gpio_init);
 475
 476 static void __exit vprbrd_gpio_exit(void)
 477 {
 478         platform_driver_unregister(&vprbrd_gpio_driver);
 479 }
 480 module_exit(vprbrd_gpio_exit);
 481
 482 MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
 483 MODULE_DESCRIPTION("GPIO driver for Nano River Techs Viperboard");
 484 MODULE_LICENSE("GPL");
 485 MODULE_ALIAS("platform:viperboard-gpio");