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