Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 | /*
* GPIO Testing Device Driver
*
* Copyright (C) 2014 Kamlakant Patel <kamlakant.patel@broadcom.com>
* Copyright (C) 2015-2016 Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/consumer.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irq_work.h>
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include "gpiolib.h"
#define GPIO_MOCKUP_NAME "gpio-mockup"
#define GPIO_MOCKUP_MAX_GC 10
enum {
DIR_IN = 0,
DIR_OUT,
};
/*
* struct gpio_pin_status - structure describing a GPIO status
* @dir: Configures direction of gpio as "in" or "out", 0=in, 1=out
* @value: Configures status of the gpio as 0(low) or 1(high)
*/
struct gpio_mockup_line_status {
int dir;
bool value;
};
struct gpio_mockup_irq_context {
struct irq_work work;
int irq;
};
struct gpio_mockup_chip {
struct gpio_chip gc;
struct gpio_mockup_line_status *lines;
struct gpio_mockup_irq_context irq_ctx;
struct dentry *dbg_dir;
};
struct gpio_mockup_dbgfs_private {
struct gpio_mockup_chip *chip;
struct gpio_desc *desc;
int offset;
};
static int gpio_mockup_ranges[GPIO_MOCKUP_MAX_GC << 1];
static int gpio_mockup_params_nr;
module_param_array(gpio_mockup_ranges, int, &gpio_mockup_params_nr, 0400);
static bool gpio_mockup_named_lines;
module_param_named(gpio_mockup_named_lines,
gpio_mockup_named_lines, bool, 0400);
static const char gpio_mockup_name_start = 'A';
static struct dentry *gpio_mockup_dbg_dir;
static int gpio_mockup_get(struct gpio_chip *gc, unsigned int offset)
{
struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
return chip->lines[offset].value;
}
static void gpio_mockup_set(struct gpio_chip *gc, unsigned int offset,
int value)
{
struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
chip->lines[offset].value = !!value;
}
static int gpio_mockup_dirout(struct gpio_chip *gc, unsigned int offset,
int value)
{
struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
gpio_mockup_set(gc, offset, value);
chip->lines[offset].dir = DIR_OUT;
return 0;
}
static int gpio_mockup_dirin(struct gpio_chip *gc, unsigned int offset)
{
struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
chip->lines[offset].dir = DIR_IN;
return 0;
}
static int gpio_mockup_get_direction(struct gpio_chip *gc, unsigned int offset)
{
struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
return chip->lines[offset].dir;
}
static int gpio_mockup_name_lines(struct device *dev,
struct gpio_mockup_chip *chip)
{
struct gpio_chip *gc = &chip->gc;
char **names;
int i;
names = devm_kzalloc(dev, sizeof(char *) * gc->ngpio, GFP_KERNEL);
if (!names)
return -ENOMEM;
for (i = 0; i < gc->ngpio; i++) {
names[i] = devm_kasprintf(dev, GFP_KERNEL,
"%s-%d", gc->label, i);
if (!names[i])
return -ENOMEM;
}
gc->names = (const char *const *)names;
return 0;
}
static int gpio_mockup_to_irq(struct gpio_chip *chip, unsigned int offset)
{
return chip->irq_base + offset;
}
/*
* While we should generally support irqmask and irqunmask, this driver is
* for testing purposes only so we don't care.
*/
static void gpio_mockup_irqmask(struct irq_data *d) { }
static void gpio_mockup_irqunmask(struct irq_data *d) { }
static struct irq_chip gpio_mockup_irqchip = {
.name = GPIO_MOCKUP_NAME,
.irq_mask = gpio_mockup_irqmask,
.irq_unmask = gpio_mockup_irqunmask,
};
static void gpio_mockup_handle_irq(struct irq_work *work)
{
struct gpio_mockup_irq_context *irq_ctx;
irq_ctx = container_of(work, struct gpio_mockup_irq_context, work);
handle_simple_irq(irq_to_desc(irq_ctx->irq));
}
static int gpio_mockup_irqchip_setup(struct device *dev,
struct gpio_mockup_chip *chip)
{
struct gpio_chip *gc = &chip->gc;
int irq_base, i;
irq_base = devm_irq_alloc_descs(dev, -1, 0, gc->ngpio, 0);
if (irq_base < 0)
return irq_base;
gc->irq_base = irq_base;
gc->irqchip = &gpio_mockup_irqchip;
for (i = 0; i < gc->ngpio; i++) {
irq_set_chip(irq_base + i, gc->irqchip);
irq_set_handler(irq_base + i, &handle_simple_irq);
irq_modify_status(irq_base + i,
IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE);
}
init_irq_work(&chip->irq_ctx.work, gpio_mockup_handle_irq);
return 0;
}
static ssize_t gpio_mockup_event_write(struct file *file,
const char __user *usr_buf,
size_t size, loff_t *ppos)
{
struct gpio_mockup_dbgfs_private *priv;
struct gpio_mockup_chip *chip;
struct seq_file *sfile;
struct gpio_desc *desc;
struct gpio_chip *gc;
int val;
char buf;
sfile = file->private_data;
priv = sfile->private;
desc = priv->desc;
chip = priv->chip;
gc = &chip->gc;
if (copy_from_user(&buf, usr_buf, 1))
return -EFAULT;
if (buf == '0')
val = 0;
else if (buf == '1')
val = 1;
else
return -EINVAL;
gpiod_set_value_cansleep(desc, val);
priv->chip->irq_ctx.irq = gc->irq_base + priv->offset;
irq_work_queue(&priv->chip->irq_ctx.work);
return size;
}
static int gpio_mockup_event_open(struct inode *inode, struct file *file)
{
return single_open(file, NULL, inode->i_private);
}
static const struct file_operations gpio_mockup_event_ops = {
.owner = THIS_MODULE,
.open = gpio_mockup_event_open,
.write = gpio_mockup_event_write,
.llseek = no_llseek,
};
static void gpio_mockup_debugfs_setup(struct device *dev,
struct gpio_mockup_chip *chip)
{
struct gpio_mockup_dbgfs_private *priv;
struct dentry *evfile;
struct gpio_chip *gc;
char *name;
int i;
gc = &chip->gc;
chip->dbg_dir = debugfs_create_dir(gc->label, gpio_mockup_dbg_dir);
if (!chip->dbg_dir)
goto err;
for (i = 0; i < gc->ngpio; i++) {
name = devm_kasprintf(dev, GFP_KERNEL, "%d", i);
if (!name)
goto err;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
goto err;
priv->chip = chip;
priv->offset = i;
priv->desc = &gc->gpiodev->descs[i];
evfile = debugfs_create_file(name, 0200, chip->dbg_dir, priv,
&gpio_mockup_event_ops);
if (!evfile)
goto err;
}
return;
err:
dev_err(dev, "error creating debugfs directory\n");
}
static int gpio_mockup_add(struct device *dev,
struct gpio_mockup_chip *chip,
const char *name, int base, int ngpio)
{
struct gpio_chip *gc = &chip->gc;
int ret;
gc->base = base;
gc->ngpio = ngpio;
gc->label = name;
gc->owner = THIS_MODULE;
gc->parent = dev;
gc->get = gpio_mockup_get;
gc->set = gpio_mockup_set;
gc->direction_output = gpio_mockup_dirout;
gc->direction_input = gpio_mockup_dirin;
gc->get_direction = gpio_mockup_get_direction;
gc->to_irq = gpio_mockup_to_irq;
chip->lines = devm_kzalloc(dev, sizeof(*chip->lines) * gc->ngpio,
GFP_KERNEL);
if (!chip->lines)
return -ENOMEM;
if (gpio_mockup_named_lines) {
ret = gpio_mockup_name_lines(dev, chip);
if (ret)
return ret;
}
ret = gpio_mockup_irqchip_setup(dev, chip);
if (ret)
return ret;
ret = devm_gpiochip_add_data(dev, &chip->gc, chip);
if (ret)
return ret;
if (gpio_mockup_dbg_dir)
gpio_mockup_debugfs_setup(dev, chip);
return 0;
}
static int gpio_mockup_probe(struct platform_device *pdev)
{
struct gpio_mockup_chip *chips;
struct device *dev = &pdev->dev;
int ret, i, base, ngpio;
char *chip_name;
if (gpio_mockup_params_nr < 2)
return -EINVAL;
chips = devm_kzalloc(dev,
sizeof(*chips) * (gpio_mockup_params_nr >> 1),
GFP_KERNEL);
if (!chips)
return -ENOMEM;
platform_set_drvdata(pdev, chips);
for (i = 0; i < gpio_mockup_params_nr >> 1; i++) {
base = gpio_mockup_ranges[i * 2];
if (base == -1)
ngpio = gpio_mockup_ranges[i * 2 + 1];
else
ngpio = gpio_mockup_ranges[i * 2 + 1] - base;
if (ngpio >= 0) {
chip_name = devm_kasprintf(dev, GFP_KERNEL,
"%s-%c", GPIO_MOCKUP_NAME,
gpio_mockup_name_start + i);
if (!chip_name)
return -ENOMEM;
ret = gpio_mockup_add(dev, &chips[i],
chip_name, base, ngpio);
} else {
ret = -1;
}
if (ret) {
dev_err(dev, "gpio<%d..%d> add failed\n",
base, base < 0 ? ngpio : base + ngpio);
return ret;
}
dev_info(dev, "gpio<%d..%d> add successful!",
base, base + ngpio);
}
return 0;
}
static struct platform_driver gpio_mockup_driver = {
.driver = {
.name = GPIO_MOCKUP_NAME,
},
.probe = gpio_mockup_probe,
};
static struct platform_device *pdev;
static int __init mock_device_init(void)
{
int err;
gpio_mockup_dbg_dir = debugfs_create_dir("gpio-mockup-event", NULL);
if (!gpio_mockup_dbg_dir)
pr_err("%s: error creating debugfs directory\n",
GPIO_MOCKUP_NAME);
pdev = platform_device_alloc(GPIO_MOCKUP_NAME, -1);
if (!pdev)
return -ENOMEM;
err = platform_device_add(pdev);
if (err) {
platform_device_put(pdev);
return err;
}
err = platform_driver_register(&gpio_mockup_driver);
if (err) {
platform_device_unregister(pdev);
return err;
}
return 0;
}
static void __exit mock_device_exit(void)
{
debugfs_remove_recursive(gpio_mockup_dbg_dir);
platform_driver_unregister(&gpio_mockup_driver);
platform_device_unregister(pdev);
}
module_init(mock_device_init);
module_exit(mock_device_exit);
MODULE_AUTHOR("Kamlakant Patel <kamlakant.patel@broadcom.com>");
MODULE_AUTHOR("Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>");
MODULE_DESCRIPTION("GPIO Testing driver");
MODULE_LICENSE("GPL v2");
|