drivers/leds/leds-sgm3140.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (C) 2020 Luca Weiss <luca@z3ntu.xyz>
   3
   4 #include <linux/gpio/consumer.h>
   5 #include <linux/led-class-flash.h>
   6 #include <linux/module.h>
   7 #include <linux/regulator/consumer.h>
   8 #include <linux/platform_device.h>
   9
  10 #include <media/v4l2-flash-led-class.h>
  11
  12 #define FLASH_TIMEOUT_DEFAULT           250000U /* 250ms */
  13 #define FLASH_MAX_TIMEOUT_DEFAULT       300000U /* 300ms */
  14
  15 struct sgm3140 {
  16         struct led_classdev_flash fled_cdev;
  17         struct v4l2_flash *v4l2_flash;
  18
  19         struct timer_list powerdown_timer;
  20
  21         struct gpio_desc *flash_gpio;
  22         struct gpio_desc *enable_gpio;
  23         struct regulator *vin_regulator;
  24
  25         bool enabled;
  26
  27         /* current timeout in us */
  28         u32 timeout;
  29         /* maximum timeout in us */
  30         u32 max_timeout;
  31 };
  32
  33 static struct sgm3140 *flcdev_to_sgm3140(struct led_classdev_flash *flcdev)
  34 {
  35         return container_of(flcdev, struct sgm3140, fled_cdev);
  36 }
  37
  38 static int sgm3140_strobe_set(struct led_classdev_flash *fled_cdev, bool state)
  39 {
  40         struct sgm3140 *priv = flcdev_to_sgm3140(fled_cdev);
  41         int ret;
  42
  43         if (priv->enabled == state)
  44                 return 0;
  45
  46         if (state) {
  47                 ret = regulator_enable(priv->vin_regulator);
  48                 if (ret) {
  49                         dev_err(fled_cdev->led_cdev.dev,
  50                                 "failed to enable regulator: %d\n", ret);
  51                         return ret;
  52                 }
  53                 gpiod_set_value_cansleep(priv->flash_gpio, 1);
  54                 gpiod_set_value_cansleep(priv->enable_gpio, 1);
  55                 mod_timer(&priv->powerdown_timer,
  56                           jiffies + usecs_to_jiffies(priv->timeout));
  57         } else {
  58                 del_timer_sync(&priv->powerdown_timer);
  59                 gpiod_set_value_cansleep(priv->enable_gpio, 0);
  60                 gpiod_set_value_cansleep(priv->flash_gpio, 0);
  61                 ret = regulator_disable(priv->vin_regulator);
  62                 if (ret) {
  63                         dev_err(fled_cdev->led_cdev.dev,
  64                                 "failed to disable regulator: %d\n", ret);
  65                         return ret;
  66                 }
  67         }
  68
  69         priv->enabled = state;
  70
  71         return 0;
  72 }
  73
  74 static int sgm3140_strobe_get(struct led_classdev_flash *fled_cdev, bool *state)
  75 {
  76         struct sgm3140 *priv = flcdev_to_sgm3140(fled_cdev);
  77
  78         *state = timer_pending(&priv->powerdown_timer);
  79
  80         return 0;
  81 }
  82
  83 static int sgm3140_timeout_set(struct led_classdev_flash *fled_cdev,
  84                                u32 timeout)
  85 {
  86         struct sgm3140 *priv = flcdev_to_sgm3140(fled_cdev);
  87
  88         priv->timeout = timeout;
  89
  90         return 0;
  91 }
  92
  93 static const struct led_flash_ops sgm3140_flash_ops = {
  94         .strobe_set = sgm3140_strobe_set,
  95         .strobe_get = sgm3140_strobe_get,
  96         .timeout_set = sgm3140_timeout_set,
  97 };
  98
  99 static int sgm3140_brightness_set(struct led_classdev *led_cdev,
 100                                   enum led_brightness brightness)
 101 {
 102         struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
 103         struct sgm3140 *priv = flcdev_to_sgm3140(fled_cdev);
 104         bool enable = brightness == LED_ON;
 105         int ret;
 106
 107         if (priv->enabled == enable)
 108                 return 0;
 109
 110         if (enable) {
 111                 ret = regulator_enable(priv->vin_regulator);
 112                 if (ret) {
 113                         dev_err(led_cdev->dev,
 114                                 "failed to enable regulator: %d\n", ret);
 115                         return ret;
 116                 }
 117                 gpiod_set_value_cansleep(priv->enable_gpio, 1);
 118         } else {
 119                 gpiod_set_value_cansleep(priv->enable_gpio, 0);
 120                 ret = regulator_disable(priv->vin_regulator);
 121                 if (ret) {
 122                         dev_err(led_cdev->dev,
 123                                 "failed to disable regulator: %d\n", ret);
 124                         return ret;
 125                 }
 126         }
 127
 128         priv->enabled = enable;
 129
 130         return 0;
 131 }
 132
 133 static void sgm3140_powerdown_timer(struct timer_list *t)
 134 {
 135         struct sgm3140 *priv = from_timer(priv, t, powerdown_timer);
 136
 137         gpiod_set_value(priv->enable_gpio, 0);
 138         gpiod_set_value(priv->flash_gpio, 0);
 139         regulator_disable(priv->vin_regulator);
 140
 141         priv->enabled = false;
 142 }
 143
 144 static void sgm3140_init_flash_timeout(struct sgm3140 *priv)
 145 {
 146         struct led_classdev_flash *fled_cdev = &priv->fled_cdev;
 147         struct led_flash_setting *s;
 148
 149         /* Init flash timeout setting */
 150         s = &fled_cdev->timeout;
 151         s->min = 1;
 152         s->max = priv->max_timeout;
 153         s->step = 1;
 154         s->val = FLASH_TIMEOUT_DEFAULT;
 155 }
 156
 157 #if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
 158 static void sgm3140_init_v4l2_flash_config(struct sgm3140 *priv,
 159                                         struct v4l2_flash_config *v4l2_sd_cfg)
 160 {
 161         struct led_classdev *led_cdev = &priv->fled_cdev.led_cdev;
 162         struct led_flash_setting *s;
 163
 164         strscpy(v4l2_sd_cfg->dev_name, led_cdev->dev->kobj.name,
 165                 sizeof(v4l2_sd_cfg->dev_name));
 166
 167         /* Init flash intensity setting */
 168         s = &v4l2_sd_cfg->intensity;
 169         s->min = 0;
 170         s->max = 1;
 171         s->step = 1;
 172         s->val = 1;
 173 }
 174
 175 #else
 176 static void sgm3140_init_v4l2_flash_config(struct sgm3140 *priv,
 177                                         struct v4l2_flash_config *v4l2_sd_cfg)
 178 {
 179 }
 180 #endif
 181
 182 static int sgm3140_probe(struct platform_device *pdev)
 183 {
 184         struct sgm3140 *priv;
 185         struct led_classdev *led_cdev;
 186         struct led_classdev_flash *fled_cdev;
 187         struct led_init_data init_data = {};
 188         struct fwnode_handle *child_node;
 189         struct v4l2_flash_config v4l2_sd_cfg = {};
 190         int ret;
 191
 192         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 193         if (!priv)
 194                 return -ENOMEM;
 195
 196         priv->flash_gpio = devm_gpiod_get(&pdev->dev, "flash", GPIOD_OUT_LOW);
 197         ret = PTR_ERR_OR_ZERO(priv->flash_gpio);
 198         if (ret)
 199                 return dev_err_probe(&pdev->dev, ret,
 200                                      "Failed to request flash gpio\n");
 201
 202         priv->enable_gpio = devm_gpiod_get(&pdev->dev, "enable", GPIOD_OUT_LOW);
 203         ret = PTR_ERR_OR_ZERO(priv->enable_gpio);
 204         if (ret)
 205                 return dev_err_probe(&pdev->dev, ret,
 206                                      "Failed to request enable gpio\n");
 207
 208         priv->vin_regulator = devm_regulator_get(&pdev->dev, "vin");
 209         ret = PTR_ERR_OR_ZERO(priv->vin_regulator);
 210         if (ret)
 211                 return dev_err_probe(&pdev->dev, ret,
 212                                      "Failed to request regulator\n");
 213
 214         child_node = fwnode_get_next_available_child_node(pdev->dev.fwnode,
 215                                                           NULL);
 216         if (!child_node) {
 217                 dev_err(&pdev->dev,
 218                         "No fwnode child node found for connected LED.\n");
 219                 return -EINVAL;
 220         }
 221
 222         ret = fwnode_property_read_u32(child_node, "flash-max-timeout-us",
 223                                        &priv->max_timeout);
 224         if (ret) {
 225                 priv->max_timeout = FLASH_MAX_TIMEOUT_DEFAULT;
 226                 dev_warn(&pdev->dev,
 227                          "flash-max-timeout-us property missing\n");
 228         }
 229
 230         /*
 231          * Set default timeout to FLASH_DEFAULT_TIMEOUT except if max_timeout
 232          * from DT is lower.
 233          */
 234         priv->timeout = min(priv->max_timeout, FLASH_TIMEOUT_DEFAULT);
 235
 236         timer_setup(&priv->powerdown_timer, sgm3140_powerdown_timer, 0);
 237
 238         fled_cdev = &priv->fled_cdev;
 239         led_cdev = &fled_cdev->led_cdev;
 240
 241         fled_cdev->ops = &sgm3140_flash_ops;
 242
 243         led_cdev->brightness_set_blocking = sgm3140_brightness_set;
 244         led_cdev->max_brightness = LED_ON;
 245         led_cdev->flags |= LED_DEV_CAP_FLASH;
 246
 247         sgm3140_init_flash_timeout(priv);
 248
 249         init_data.fwnode = child_node;
 250
 251         platform_set_drvdata(pdev, priv);
 252
 253         /* Register in the LED subsystem */
 254         ret = devm_led_classdev_flash_register_ext(&pdev->dev,
 255                                                    fled_cdev, &init_data);
 256         if (ret) {
 257                 dev_err(&pdev->dev, "Failed to register flash device: %d\n",
 258                         ret);
 259                 goto err;
 260         }
 261
 262         sgm3140_init_v4l2_flash_config(priv, &v4l2_sd_cfg);
 263
 264         /* Create V4L2 Flash subdev */
 265         priv->v4l2_flash = v4l2_flash_init(&pdev->dev,
 266                                            child_node,
 267                                            fled_cdev, NULL,
 268                                            &v4l2_sd_cfg);
 269         if (IS_ERR(priv->v4l2_flash)) {
 270                 ret = PTR_ERR(priv->v4l2_flash);
 271                 goto err;
 272         }
 273
 274         return ret;
 275
 276 err:
 277         fwnode_handle_put(child_node);
 278         return ret;
 279 }
 280
 281 static int sgm3140_remove(struct platform_device *pdev)
 282 {
 283         struct sgm3140 *priv = platform_get_drvdata(pdev);
 284
 285         del_timer_sync(&priv->powerdown_timer);
 286
 287         v4l2_flash_release(priv->v4l2_flash);
 288
 289         return 0;
 290 }
 291
 292 static const struct of_device_id sgm3140_dt_match[] = {
 293         { .compatible = "sgmicro,sgm3140" },
 294         { /* sentinel */ }
 295 };
 296 MODULE_DEVICE_TABLE(of, sgm3140_dt_match);
 297
 298 static struct platform_driver sgm3140_driver = {
 299         .probe  = sgm3140_probe,
 300         .remove = sgm3140_remove,
 301         .driver = {
 302                 .name   = "sgm3140",
 303                 .of_match_table = sgm3140_dt_match,
 304         },
 305 };
 306
 307 module_platform_driver(sgm3140_driver);
 308
 309 MODULE_AUTHOR("Luca Weiss <luca@z3ntu.xyz>");
 310 MODULE_DESCRIPTION("SG Micro SGM3140 charge pump LED driver");
 311 MODULE_LICENSE("GPL v2");