root/drivers/leds/leds-mlxreg.c

DEFINITIONS

1. mlxreg_led_store_hw
2. mlxreg_led_get_hw
3. mlxreg_led_brightness_set
4. mlxreg_led_brightness_get
5. mlxreg_led_blink_set
6. mlxreg_led_config
7. mlxreg_led_probe
8. mlxreg_led_remove

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