linux/drivers/gpio/gpio-viperboard.c
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   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
  48struct 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
  62struct vprbrd_gpiob_msg {
  63        u8 cmd;
  64        u16 val;
  65        u16 mask;
  66} __packed;
  67
  68struct 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 */
  79static unsigned char gpioa_clk;
  80static unsigned int gpioa_freq = VPRBRD_GPIOA_FREQ_DEFAULT;
  81module_param(gpioa_freq, uint, 0);
  82MODULE_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
  87static 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
 138static 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
 180static 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
 218static 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
 264static 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
 285static 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
 318static 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
 352static 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
 374static 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        if (value)
 384                gpio->gpiob_val |= (1 << offset);
 385        else
 386                gpio->gpiob_val &= ~(1 << offset);
 387
 388        mutex_lock(&vb->lock);
 389
 390        ret = vprbrd_gpiob_setdir(vb, offset, 1);
 391        if (ret)
 392                dev_err(chip->dev, "usb error setting pin to output\n");
 393
 394        mutex_unlock(&vb->lock);
 395
 396        vprbrd_gpiob_set(chip, offset, value);
 397
 398        return ret;
 399}
 400
 401/* ----- end of gpio b chip ---------------------------------------------- */
 402
 403static int vprbrd_gpio_probe(struct platform_device *pdev)
 404{
 405        struct vprbrd *vb = dev_get_drvdata(pdev->dev.parent);
 406        struct vprbrd_gpio *vb_gpio;
 407        int ret;
 408
 409        vb_gpio = devm_kzalloc(&pdev->dev, sizeof(*vb_gpio), GFP_KERNEL);
 410        if (vb_gpio == NULL)
 411                return -ENOMEM;
 412
 413        vb_gpio->vb = vb;
 414        /* registering gpio a */
 415        vb_gpio->gpioa.label = "viperboard gpio a";
 416        vb_gpio->gpioa.dev = &pdev->dev;
 417        vb_gpio->gpioa.owner = THIS_MODULE;
 418        vb_gpio->gpioa.base = -1;
 419        vb_gpio->gpioa.ngpio = 16;
 420        vb_gpio->gpioa.can_sleep = 1;
 421        vb_gpio->gpioa.set = vprbrd_gpioa_set;
 422        vb_gpio->gpioa.get = vprbrd_gpioa_get;
 423        vb_gpio->gpioa.direction_input = vprbrd_gpioa_direction_input;
 424        vb_gpio->gpioa.direction_output = vprbrd_gpioa_direction_output;
 425        ret = gpiochip_add(&vb_gpio->gpioa);
 426        if (ret < 0) {
 427                dev_err(vb_gpio->gpioa.dev, "could not add gpio a");
 428                goto err_gpioa;
 429        }
 430
 431        /* registering gpio b */
 432        vb_gpio->gpiob.label = "viperboard gpio b";
 433        vb_gpio->gpiob.dev = &pdev->dev;
 434        vb_gpio->gpiob.owner = THIS_MODULE;
 435        vb_gpio->gpiob.base = -1;
 436        vb_gpio->gpiob.ngpio = 16;
 437        vb_gpio->gpiob.can_sleep = 1;
 438        vb_gpio->gpiob.set = vprbrd_gpiob_set;
 439        vb_gpio->gpiob.get = vprbrd_gpiob_get;
 440        vb_gpio->gpiob.direction_input = vprbrd_gpiob_direction_input;
 441        vb_gpio->gpiob.direction_output = vprbrd_gpiob_direction_output;
 442        ret = gpiochip_add(&vb_gpio->gpiob);
 443        if (ret < 0) {
 444                dev_err(vb_gpio->gpiob.dev, "could not add gpio b");
 445                goto err_gpiob;
 446        }
 447
 448        platform_set_drvdata(pdev, vb_gpio);
 449
 450        return ret;
 451
 452err_gpiob:
 453        ret = gpiochip_remove(&vb_gpio->gpioa);
 454
 455err_gpioa:
 456        return ret;
 457}
 458
 459static int vprbrd_gpio_remove(struct platform_device *pdev)
 460{
 461        struct vprbrd_gpio *vb_gpio = platform_get_drvdata(pdev);
 462        int ret;
 463
 464        ret = gpiochip_remove(&vb_gpio->gpiob);
 465        if (ret == 0)
 466                ret = gpiochip_remove(&vb_gpio->gpioa);
 467
 468        return ret;
 469}
 470
 471static struct platform_driver vprbrd_gpio_driver = {
 472        .driver.name    = "viperboard-gpio",
 473        .driver.owner   = THIS_MODULE,
 474        .probe          = vprbrd_gpio_probe,
 475        .remove         = vprbrd_gpio_remove,
 476};
 477
 478static int __init vprbrd_gpio_init(void)
 479{
 480        switch (gpioa_freq) {
 481        case 1000000:
 482                gpioa_clk = VPRBRD_GPIOA_CLK_1MHZ;
 483                break;
 484        case 100000:
 485                gpioa_clk = VPRBRD_GPIOA_CLK_100KHZ;
 486                break;
 487        case 10000:
 488                gpioa_clk = VPRBRD_GPIOA_CLK_10KHZ;
 489                break;
 490        case 1000:
 491                gpioa_clk = VPRBRD_GPIOA_CLK_1KHZ;
 492                break;
 493        case 100:
 494                gpioa_clk = VPRBRD_GPIOA_CLK_100HZ;
 495                break;
 496        case 10:
 497                gpioa_clk = VPRBRD_GPIOA_CLK_10HZ;
 498                break;
 499        default:
 500                pr_warn("invalid gpioa_freq (%d)\n", gpioa_freq);
 501                gpioa_clk = VPRBRD_GPIOA_CLK_1KHZ;
 502        }
 503
 504        return platform_driver_register(&vprbrd_gpio_driver);
 505}
 506subsys_initcall(vprbrd_gpio_init);
 507
 508static void __exit vprbrd_gpio_exit(void)
 509{
 510        platform_driver_unregister(&vprbrd_gpio_driver);
 511}
 512module_exit(vprbrd_gpio_exit);
 513
 514MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
 515MODULE_DESCRIPTION("GPIO driver for Nano River Techs Viperboard");
 516MODULE_LICENSE("GPL");
 517MODULE_ALIAS("platform:viperboard-gpio");
 518
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