drivers/leds/leds-mlxreg.c

   1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
   2 //
   3 // Copyright (c) 2018 Mellanox Technologies. All rights reserved.
   4 // Copyright (c) 2018 Vadim Pasternak <vadimp@mellanox.com>
   5
   6 #include <linux/bitops.h>
   7 #include <linux/device.h>
   8 #include <linux/io.h>
   9 #include <linux/leds.h>
  10 #include <linux/module.h>
  11 #include <linux/of_device.h>
  12 #include <linux/platform_data/mlxreg.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/regmap.h>
  15
  16 /* Codes for LEDs. */
  17 #define MLXREG_LED_OFFSET_BLINK_3HZ     0x01 /* Offset from solid: 3Hz blink */
  18 #define MLXREG_LED_OFFSET_BLINK_6HZ     0x02 /* Offset from solid: 6Hz blink */
  19 #define MLXREG_LED_IS_OFF               0x00 /* Off */
  20 #define MLXREG_LED_RED_SOLID            0x05 /* Solid red */
  21 #define MLXREG_LED_GREEN_SOLID          0x0D /* Solid green */
  22 #define MLXREG_LED_AMBER_SOLID          0x09 /* Solid amber */
  23 #define MLXREG_LED_BLINK_3HZ            167 /* ~167 msec off/on - HW support */
  24 #define MLXREG_LED_BLINK_6HZ            83 /* ~83 msec off/on - HW support */
  25 #define MLXREG_LED_CAPABILITY_CLEAR     GENMASK(31, 8) /* Clear mask */
  26
  27 /**
  28  * struct mlxreg_led_data - led control data:
  29  *
  30  * @data: led configuration data;
  31  * @led_cdev: led class data;
  32  * @base_color: base led color (other colors have constant offset from base);
  33  * @led_data: led data;
  34  * @data_parent: pointer to private device control data of parent;
  35  * @led_cdev_name: class device name
  36  */
  37 struct mlxreg_led_data {
  38         struct mlxreg_core_data *data;
  39         struct led_classdev led_cdev;
  40         u8 base_color;
  41         void *data_parent;
  42         char led_cdev_name[MLXREG_CORE_LABEL_MAX_SIZE];
  43 };
  44
  45 #define cdev_to_priv(c) container_of(c, struct mlxreg_led_data, led_cdev)
  46
  47 /**
  48  * struct mlxreg_led_priv_data - platform private data:
  49  *
  50  * @pdev: platform device;
  51  * @pdata: platform data;
  52  * @access_lock: mutex for attribute IO access;
  53  */
  54 struct mlxreg_led_priv_data {
  55         struct platform_device *pdev;
  56         struct mlxreg_core_platform_data *pdata;
  57         struct mutex access_lock; /* protect IO operations */
  58 };
  59
  60 static int
  61 mlxreg_led_store_hw(struct mlxreg_led_data *led_data, u8 vset)
  62 {
  63         struct mlxreg_led_priv_data *priv = led_data->data_parent;
  64         struct mlxreg_core_platform_data *led_pdata = priv->pdata;
  65         struct mlxreg_core_data *data = led_data->data;
  66         u32 regval;
  67         u32 nib;
  68         int ret;
  69
  70         /*
  71          * Each LED is controlled through low or high nibble of the relevant
  72          * register byte. Register offset is specified by off parameter.
  73          * Parameter vset provides color code: 0x0 for off, 0x5 for solid red,
  74          * 0x6 for 3Hz blink red, 0xd for solid green, 0xe for 3Hz blink
  75          * green.
  76          * Parameter mask specifies which nibble is used for specific LED: mask
  77          * 0xf0 - lower nibble is to be used (bits from 0 to 3), mask 0x0f -
  78          * higher nibble (bits from 4 to 7).
  79          */
  80         mutex_lock(&priv->access_lock);
  81
  82         ret = regmap_read(led_pdata->regmap, data->reg, &regval);
  83         if (ret)
  84                 goto access_error;
  85
  86         nib = (ror32(data->mask, data->bit) == 0xf0) ? rol32(vset, data->bit) :
  87               rol32(vset, data->bit + 4);
  88         regval = (regval & data->mask) | nib;
  89
  90         ret = regmap_write(led_pdata->regmap, data->reg, regval);
  91
  92 access_error:
  93         mutex_unlock(&priv->access_lock);
  94
  95         return ret;
  96 }
  97
  98 static enum led_brightness
  99 mlxreg_led_get_hw(struct mlxreg_led_data *led_data)
 100 {
 101         struct mlxreg_led_priv_data *priv = led_data->data_parent;
 102         struct mlxreg_core_platform_data *led_pdata = priv->pdata;
 103         struct mlxreg_core_data *data = led_data->data;
 104         u32 regval;
 105         int err;
 106
 107         /*
 108          * Each LED is controlled through low or high nibble of the relevant
 109          * register byte. Register offset is specified by off parameter.
 110          * Parameter vset provides color code: 0x0 for off, 0x5 for solid red,
 111          * 0x6 for 3Hz blink red, 0xd for solid green, 0xe for 3Hz blink
 112          * green.
 113          * Parameter mask specifies which nibble is used for specific LED: mask
 114          * 0xf0 - lower nibble is to be used (bits from 0 to 3), mask 0x0f -
 115          * higher nibble (bits from 4 to 7).
 116          */
 117         err = regmap_read(led_pdata->regmap, data->reg, &regval);
 118         if (err < 0) {
 119                 dev_warn(led_data->led_cdev.dev, "Failed to get current brightness, error: %d\n",
 120                          err);
 121                 /* Assume the LED is OFF */
 122                 return LED_OFF;
 123         }
 124
 125         regval = regval & ~data->mask;
 126         regval = (ror32(data->mask, data->bit) == 0xf0) ? ror32(regval,
 127                  data->bit) : ror32(regval, data->bit + 4);
 128         if (regval >= led_data->base_color &&
 129             regval <= (led_data->base_color + MLXREG_LED_OFFSET_BLINK_6HZ))
 130                 return LED_FULL;
 131
 132         return LED_OFF;
 133 }
 134
 135 static int
 136 mlxreg_led_brightness_set(struct led_classdev *cled, enum led_brightness value)
 137 {
 138         struct mlxreg_led_data *led_data = cdev_to_priv(cled);
 139
 140         if (value)
 141                 return mlxreg_led_store_hw(led_data, led_data->base_color);
 142         else
 143                 return mlxreg_led_store_hw(led_data, MLXREG_LED_IS_OFF);
 144 }
 145
 146 static enum led_brightness
 147 mlxreg_led_brightness_get(struct led_classdev *cled)
 148 {
 149         struct mlxreg_led_data *led_data = cdev_to_priv(cled);
 150
 151         return mlxreg_led_get_hw(led_data);
 152 }
 153
 154 static int
 155 mlxreg_led_blink_set(struct led_classdev *cled, unsigned long *delay_on,
 156                      unsigned long *delay_off)
 157 {
 158         struct mlxreg_led_data *led_data = cdev_to_priv(cled);
 159         int err;
 160
 161         /*
 162          * HW supports two types of blinking: full (6Hz) and half (3Hz).
 163          * For delay on/off zero LED is setting to solid color. For others
 164          * combination blinking is to be controlled by the software timer.
 165          */
 166         if (!(*delay_on == 0 && *delay_off == 0) &&
 167             !(*delay_on == MLXREG_LED_BLINK_3HZ &&
 168               *delay_off == MLXREG_LED_BLINK_3HZ) &&
 169             !(*delay_on == MLXREG_LED_BLINK_6HZ &&
 170               *delay_off == MLXREG_LED_BLINK_6HZ))
 171                 return -EINVAL;
 172
 173         if (*delay_on == MLXREG_LED_BLINK_6HZ)
 174                 err = mlxreg_led_store_hw(led_data, led_data->base_color +
 175                                           MLXREG_LED_OFFSET_BLINK_6HZ);
 176         else if (*delay_on == MLXREG_LED_BLINK_3HZ)
 177                 err = mlxreg_led_store_hw(led_data, led_data->base_color +
 178                                           MLXREG_LED_OFFSET_BLINK_3HZ);
 179         else
 180                 err = mlxreg_led_store_hw(led_data, led_data->base_color);
 181
 182         return err;
 183 }
 184
 185 static int mlxreg_led_config(struct mlxreg_led_priv_data *priv)
 186 {
 187         struct mlxreg_core_platform_data *led_pdata = priv->pdata;
 188         struct mlxreg_core_data *data = led_pdata->data;
 189         struct mlxreg_led_data *led_data;
 190         struct led_classdev *led_cdev;
 191         enum led_brightness brightness;
 192         u32 regval;
 193         int i;
 194         int err;
 195
 196         for (i = 0; i < led_pdata->counter; i++, data++) {
 197                 led_data = devm_kzalloc(&priv->pdev->dev, sizeof(*led_data),
 198                                         GFP_KERNEL);
 199                 if (!led_data)
 200                         return -ENOMEM;
 201
 202                 if (data->capability) {
 203                         err = regmap_read(led_pdata->regmap, data->capability,
 204                                           &regval);
 205                         if (err) {
 206                                 dev_err(&priv->pdev->dev, "Failed to query capability register\n");
 207                                 return err;
 208                         }
 209                         if (!(regval & data->bit))
 210                                 continue;
 211                         /*
 212                          * Field "bit" can contain one capability bit in 0 byte
 213                          * and offset bit in 1-3 bytes. Clear capability bit and
 214                          * keep only offset bit.
 215                          */
 216                         data->bit &= MLXREG_LED_CAPABILITY_CLEAR;
 217                 }
 218
 219                 led_cdev = &led_data->led_cdev;
 220                 led_data->data_parent = priv;
 221                 if (strstr(data->label, "red") ||
 222                     strstr(data->label, "orange")) {
 223                         brightness = LED_OFF;
 224                         led_data->base_color = MLXREG_LED_RED_SOLID;
 225                 } else if (strstr(data->label, "amber")) {
 226                         brightness = LED_OFF;
 227                         led_data->base_color = MLXREG_LED_AMBER_SOLID;
 228                 } else {
 229                         brightness = LED_OFF;
 230                         led_data->base_color = MLXREG_LED_GREEN_SOLID;
 231                 }
 232                 snprintf(led_data->led_cdev_name, sizeof(led_data->led_cdev_name),
 233                          "mlxreg:%s", data->label);
 234                 led_cdev->name = led_data->led_cdev_name;
 235                 led_cdev->brightness = brightness;
 236                 led_cdev->max_brightness = LED_ON;
 237                 led_cdev->brightness_set_blocking =
 238                                                 mlxreg_led_brightness_set;
 239                 led_cdev->brightness_get = mlxreg_led_brightness_get;
 240                 led_cdev->blink_set = mlxreg_led_blink_set;
 241                 led_cdev->flags = LED_CORE_SUSPENDRESUME;
 242                 led_data->data = data;
 243                 err = devm_led_classdev_register(&priv->pdev->dev, led_cdev);
 244                 if (err)
 245                         return err;
 246
 247                 if (led_cdev->brightness)
 248                         mlxreg_led_brightness_set(led_cdev,
 249                                                   led_cdev->brightness);
 250                 dev_info(led_cdev->dev, "label: %s, mask: 0x%02x, offset:0x%02x\n",
 251                          data->label, data->mask, data->reg);
 252         }
 253
 254         return 0;
 255 }
 256
 257 static int mlxreg_led_probe(struct platform_device *pdev)
 258 {
 259         struct mlxreg_core_platform_data *led_pdata;
 260         struct mlxreg_led_priv_data *priv;
 261
 262         led_pdata = dev_get_platdata(&pdev->dev);
 263         if (!led_pdata) {
 264                 dev_err(&pdev->dev, "Failed to get platform data.\n");
 265                 return -EINVAL;
 266         }
 267
 268         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 269         if (!priv)
 270                 return -ENOMEM;
 271
 272         mutex_init(&priv->access_lock);
 273         priv->pdev = pdev;
 274         priv->pdata = led_pdata;
 275
 276         return mlxreg_led_config(priv);
 277 }
 278
 279 static int mlxreg_led_remove(struct platform_device *pdev)
 280 {
 281         struct mlxreg_led_priv_data *priv = dev_get_drvdata(&pdev->dev);
 282
 283         mutex_destroy(&priv->access_lock);
 284
 285         return 0;
 286 }
 287
 288 static struct platform_driver mlxreg_led_driver = {
 289         .driver = {
 290             .name = "leds-mlxreg",
 291         },
 292         .probe = mlxreg_led_probe,
 293         .remove = mlxreg_led_remove,
 294 };
 295
 296 module_platform_driver(mlxreg_led_driver);
 297
 298 MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
 299 MODULE_DESCRIPTION("Mellanox LED regmap driver");
 300 MODULE_LICENSE("Dual BSD/GPL");
 301 MODULE_ALIAS("platform:leds-mlxreg");