drivers/leds/leds-ns2.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * leds-ns2.c - Driver for the Network Space v2 (and parents) dual-GPIO LED
   4  *
   5  * Copyright (C) 2010 LaCie
   6  *
   7  * Author: Simon Guinot <sguinot@lacie.com>
   8  *
   9  * Based on leds-gpio.c by Raphael Assenat <raph@8d.com>
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/slab.h>
  15 #include <linux/gpio.h>
  16 #include <linux/leds.h>
  17 #include <linux/module.h>
  18 #include <linux/platform_data/leds-kirkwood-ns2.h>
  19 #include <linux/of.h>
  20 #include <linux/of_gpio.h>
  21 #include "leds.h"
  22
  23 /*
  24  * The Network Space v2 dual-GPIO LED is wired to a CPLD. Three different LED
  25  * modes are available: off, on and SATA activity blinking. The LED modes are
  26  * controlled through two GPIOs (command and slow): each combination of values
  27  * for the command/slow GPIOs corresponds to a LED mode.
  28  */
  29
  30 struct ns2_led_data {
  31         struct led_classdev     cdev;
  32         unsigned int            cmd;
  33         unsigned int            slow;
  34         bool                    can_sleep;
  35         unsigned char           sata; /* True when SATA mode active. */
  36         rwlock_t                rw_lock; /* Lock GPIOs. */
  37         int                     num_modes;
  38         struct ns2_led_modval   *modval;
  39 };
  40
  41 static int ns2_led_get_mode(struct ns2_led_data *led_dat,
  42                             enum ns2_led_modes *mode)
  43 {
  44         int i;
  45         int ret = -EINVAL;
  46         int cmd_level;
  47         int slow_level;
  48
  49         cmd_level = gpio_get_value_cansleep(led_dat->cmd);
  50         slow_level = gpio_get_value_cansleep(led_dat->slow);
  51
  52         for (i = 0; i < led_dat->num_modes; i++) {
  53                 if (cmd_level == led_dat->modval[i].cmd_level &&
  54                     slow_level == led_dat->modval[i].slow_level) {
  55                         *mode = led_dat->modval[i].mode;
  56                         ret = 0;
  57                         break;
  58                 }
  59         }
  60
  61         return ret;
  62 }
  63
  64 static void ns2_led_set_mode(struct ns2_led_data *led_dat,
  65                              enum ns2_led_modes mode)
  66 {
  67         int i;
  68         bool found = false;
  69         unsigned long flags;
  70
  71         for (i = 0; i < led_dat->num_modes; i++)
  72                 if (mode == led_dat->modval[i].mode) {
  73                         found = true;
  74                         break;
  75                 }
  76
  77         if (!found)
  78                 return;
  79
  80         write_lock_irqsave(&led_dat->rw_lock, flags);
  81
  82         if (!led_dat->can_sleep) {
  83                 gpio_set_value(led_dat->cmd,
  84                                led_dat->modval[i].cmd_level);
  85                 gpio_set_value(led_dat->slow,
  86                                led_dat->modval[i].slow_level);
  87                 goto exit_unlock;
  88         }
  89
  90         gpio_set_value_cansleep(led_dat->cmd, led_dat->modval[i].cmd_level);
  91         gpio_set_value_cansleep(led_dat->slow, led_dat->modval[i].slow_level);
  92
  93 exit_unlock:
  94         write_unlock_irqrestore(&led_dat->rw_lock, flags);
  95 }
  96
  97 static void ns2_led_set(struct led_classdev *led_cdev,
  98                         enum led_brightness value)
  99 {
 100         struct ns2_led_data *led_dat =
 101                 container_of(led_cdev, struct ns2_led_data, cdev);
 102         enum ns2_led_modes mode;
 103
 104         if (value == LED_OFF)
 105                 mode = NS_V2_LED_OFF;
 106         else if (led_dat->sata)
 107                 mode = NS_V2_LED_SATA;
 108         else
 109                 mode = NS_V2_LED_ON;
 110
 111         ns2_led_set_mode(led_dat, mode);
 112 }
 113
 114 static int ns2_led_set_blocking(struct led_classdev *led_cdev,
 115                         enum led_brightness value)
 116 {
 117         ns2_led_set(led_cdev, value);
 118         return 0;
 119 }
 120
 121 static ssize_t ns2_led_sata_store(struct device *dev,
 122                                   struct device_attribute *attr,
 123                                   const char *buff, size_t count)
 124 {
 125         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 126         struct ns2_led_data *led_dat =
 127                 container_of(led_cdev, struct ns2_led_data, cdev);
 128         int ret;
 129         unsigned long enable;
 130
 131         ret = kstrtoul(buff, 10, &enable);
 132         if (ret < 0)
 133                 return ret;
 134
 135         enable = !!enable;
 136
 137         if (led_dat->sata == enable)
 138                 goto exit;
 139
 140         led_dat->sata = enable;
 141
 142         if (!led_get_brightness(led_cdev))
 143                 goto exit;
 144
 145         if (enable)
 146                 ns2_led_set_mode(led_dat, NS_V2_LED_SATA);
 147         else
 148                 ns2_led_set_mode(led_dat, NS_V2_LED_ON);
 149
 150 exit:
 151         return count;
 152 }
 153
 154 static ssize_t ns2_led_sata_show(struct device *dev,
 155                                  struct device_attribute *attr, char *buf)
 156 {
 157         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 158         struct ns2_led_data *led_dat =
 159                 container_of(led_cdev, struct ns2_led_data, cdev);
 160
 161         return sprintf(buf, "%d\n", led_dat->sata);
 162 }
 163
 164 static DEVICE_ATTR(sata, 0644, ns2_led_sata_show, ns2_led_sata_store);
 165
 166 static struct attribute *ns2_led_attrs[] = {
 167         &dev_attr_sata.attr,
 168         NULL
 169 };
 170 ATTRIBUTE_GROUPS(ns2_led);
 171
 172 static int
 173 create_ns2_led(struct platform_device *pdev, struct ns2_led_data *led_dat,
 174                const struct ns2_led *template)
 175 {
 176         int ret;
 177         enum ns2_led_modes mode;
 178
 179         ret = devm_gpio_request_one(&pdev->dev, template->cmd,
 180                         gpio_get_value_cansleep(template->cmd) ?
 181                         GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW,
 182                         template->name);
 183         if (ret) {
 184                 dev_err(&pdev->dev, "%s: failed to setup command GPIO\n",
 185                         template->name);
 186                 return ret;
 187         }
 188
 189         ret = devm_gpio_request_one(&pdev->dev, template->slow,
 190                         gpio_get_value_cansleep(template->slow) ?
 191                         GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW,
 192                         template->name);
 193         if (ret) {
 194                 dev_err(&pdev->dev, "%s: failed to setup slow GPIO\n",
 195                         template->name);
 196                 return ret;
 197         }
 198
 199         rwlock_init(&led_dat->rw_lock);
 200
 201         led_dat->cdev.name = template->name;
 202         led_dat->cdev.default_trigger = template->default_trigger;
 203         led_dat->cdev.blink_set = NULL;
 204         led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
 205         led_dat->cdev.groups = ns2_led_groups;
 206         led_dat->cmd = template->cmd;
 207         led_dat->slow = template->slow;
 208         led_dat->can_sleep = gpio_cansleep(led_dat->cmd) |
 209                                 gpio_cansleep(led_dat->slow);
 210         if (led_dat->can_sleep)
 211                 led_dat->cdev.brightness_set_blocking = ns2_led_set_blocking;
 212         else
 213                 led_dat->cdev.brightness_set = ns2_led_set;
 214         led_dat->modval = template->modval;
 215         led_dat->num_modes = template->num_modes;
 216
 217         ret = ns2_led_get_mode(led_dat, &mode);
 218         if (ret < 0)
 219                 return ret;
 220
 221         /* Set LED initial state. */
 222         led_dat->sata = (mode == NS_V2_LED_SATA) ? 1 : 0;
 223         led_dat->cdev.brightness =
 224                 (mode == NS_V2_LED_OFF) ? LED_OFF : LED_FULL;
 225
 226         ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
 227         if (ret < 0)
 228                 return ret;
 229
 230         return 0;
 231 }
 232
 233 static void delete_ns2_led(struct ns2_led_data *led_dat)
 234 {
 235         led_classdev_unregister(&led_dat->cdev);
 236 }
 237
 238 #ifdef CONFIG_OF_GPIO
 239 /*
 240  * Translate OpenFirmware node properties into platform_data.
 241  */
 242 static int
 243 ns2_leds_get_of_pdata(struct device *dev, struct ns2_led_platform_data *pdata)
 244 {
 245         struct device_node *np = dev->of_node;
 246         struct device_node *child;
 247         struct ns2_led *led, *leds;
 248         int num_leds = 0;
 249
 250         num_leds = of_get_child_count(np);
 251         if (!num_leds)
 252                 return -ENODEV;
 253
 254         leds = devm_kcalloc(dev, num_leds, sizeof(struct ns2_led),
 255                             GFP_KERNEL);
 256         if (!leds)
 257                 return -ENOMEM;
 258
 259         led = leds;
 260         for_each_child_of_node(np, child) {
 261                 const char *string;
 262                 int ret, i, num_modes;
 263                 struct ns2_led_modval *modval;
 264
 265                 ret = of_get_named_gpio(child, "cmd-gpio", 0);
 266                 if (ret < 0)
 267                         return ret;
 268                 led->cmd = ret;
 269                 ret = of_get_named_gpio(child, "slow-gpio", 0);
 270                 if (ret < 0)
 271                         return ret;
 272                 led->slow = ret;
 273                 ret = of_property_read_string(child, "label", &string);
 274                 led->name = (ret == 0) ? string : child->name;
 275                 ret = of_property_read_string(child, "linux,default-trigger",
 276                                               &string);
 277                 if (ret == 0)
 278                         led->default_trigger = string;
 279
 280                 ret = of_property_count_u32_elems(child, "modes-map");
 281                 if (ret < 0 || ret % 3) {
 282                         dev_err(dev,
 283                                 "Missing or malformed modes-map property\n");
 284                         return -EINVAL;
 285                 }
 286
 287                 num_modes = ret / 3;
 288                 modval = devm_kcalloc(dev,
 289                                       num_modes,
 290                                       sizeof(struct ns2_led_modval),
 291                                       GFP_KERNEL);
 292                 if (!modval)
 293                         return -ENOMEM;
 294
 295                 for (i = 0; i < num_modes; i++) {
 296                         of_property_read_u32_index(child,
 297                                                 "modes-map", 3 * i,
 298                                                 (u32 *) &modval[i].mode);
 299                         of_property_read_u32_index(child,
 300                                                 "modes-map", 3 * i + 1,
 301                                                 (u32 *) &modval[i].cmd_level);
 302                         of_property_read_u32_index(child,
 303                                                 "modes-map", 3 * i + 2,
 304                                                 (u32 *) &modval[i].slow_level);
 305                 }
 306
 307                 led->num_modes = num_modes;
 308                 led->modval = modval;
 309
 310                 led++;
 311         }
 312
 313         pdata->leds = leds;
 314         pdata->num_leds = num_leds;
 315
 316         return 0;
 317 }
 318
 319 static const struct of_device_id of_ns2_leds_match[] = {
 320         { .compatible = "lacie,ns2-leds", },
 321         {},
 322 };
 323 MODULE_DEVICE_TABLE(of, of_ns2_leds_match);
 324 #endif /* CONFIG_OF_GPIO */
 325
 326 struct ns2_led_priv {
 327         int num_leds;
 328         struct ns2_led_data leds_data[];
 329 };
 330
 331 static inline int sizeof_ns2_led_priv(int num_leds)
 332 {
 333         return sizeof(struct ns2_led_priv) +
 334                       (sizeof(struct ns2_led_data) * num_leds);
 335 }
 336
 337 static int ns2_led_probe(struct platform_device *pdev)
 338 {
 339         struct ns2_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
 340         struct ns2_led_priv *priv;
 341         int i;
 342         int ret;
 343
 344 #ifdef CONFIG_OF_GPIO
 345         if (!pdata) {
 346                 pdata = devm_kzalloc(&pdev->dev,
 347                                      sizeof(struct ns2_led_platform_data),
 348                                      GFP_KERNEL);
 349                 if (!pdata)
 350                         return -ENOMEM;
 351
 352                 ret = ns2_leds_get_of_pdata(&pdev->dev, pdata);
 353                 if (ret)
 354                         return ret;
 355         }
 356 #else
 357         if (!pdata)
 358                 return -EINVAL;
 359 #endif /* CONFIG_OF_GPIO */
 360
 361         priv = devm_kzalloc(&pdev->dev,
 362                             sizeof_ns2_led_priv(pdata->num_leds), GFP_KERNEL);
 363         if (!priv)
 364                 return -ENOMEM;
 365         priv->num_leds = pdata->num_leds;
 366
 367         for (i = 0; i < priv->num_leds; i++) {
 368                 ret = create_ns2_led(pdev, &priv->leds_data[i],
 369                                      &pdata->leds[i]);
 370                 if (ret < 0) {
 371                         for (i = i - 1; i >= 0; i--)
 372                                 delete_ns2_led(&priv->leds_data[i]);
 373                         return ret;
 374                 }
 375         }
 376
 377         platform_set_drvdata(pdev, priv);
 378
 379         return 0;
 380 }
 381
 382 static int ns2_led_remove(struct platform_device *pdev)
 383 {
 384         int i;
 385         struct ns2_led_priv *priv;
 386
 387         priv = platform_get_drvdata(pdev);
 388
 389         for (i = 0; i < priv->num_leds; i++)
 390                 delete_ns2_led(&priv->leds_data[i]);
 391
 392         return 0;
 393 }
 394
 395 static struct platform_driver ns2_led_driver = {
 396         .probe          = ns2_led_probe,
 397         .remove         = ns2_led_remove,
 398         .driver         = {
 399                 .name           = "leds-ns2",
 400                 .of_match_table = of_match_ptr(of_ns2_leds_match),
 401         },
 402 };
 403
 404 module_platform_driver(ns2_led_driver);
 405
 406 MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
 407 MODULE_DESCRIPTION("Network Space v2 LED driver");
 408 MODULE_LICENSE("GPL");
 409 MODULE_ALIAS("platform:leds-ns2");