leds-mlxreg.c 8.8 KB

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