leds-lp8788.c 3.7 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * TI LP8788 MFD - keyled driver
  4. *
  5. * Copyright 2012 Texas Instruments
  6. *
  7. * Author: Milo(Woogyom) Kim <milo.kim@ti.com>
  8. */
  9. #include <linux/module.h>
  10. #include <linux/slab.h>
  11. #include <linux/err.h>
  12. #include <linux/platform_device.h>
  13. #include <linux/leds.h>
  14. #include <linux/mutex.h>
  15. #include <linux/mfd/lp8788.h>
  16. #include <linux/mfd/lp8788-isink.h>
  17. #define MAX_BRIGHTNESS LP8788_ISINK_MAX_PWM
  18. #define DEFAULT_LED_NAME "keyboard-backlight"
  19. struct lp8788_led {
  20. struct lp8788 *lp;
  21. struct mutex lock;
  22. struct led_classdev led_dev;
  23. enum lp8788_isink_number isink_num;
  24. int on;
  25. };
  26. struct lp8788_led_config {
  27. enum lp8788_isink_scale scale;
  28. enum lp8788_isink_number num;
  29. int iout;
  30. };
  31. static struct lp8788_led_config default_led_config = {
  32. .scale = LP8788_ISINK_SCALE_100mA,
  33. .num = LP8788_ISINK_3,
  34. .iout = 0,
  35. };
  36. static int lp8788_led_init_device(struct lp8788_led *led,
  37. struct lp8788_led_platform_data *pdata)
  38. {
  39. struct lp8788_led_config *cfg = &default_led_config;
  40. u8 addr, mask, val;
  41. int ret;
  42. if (pdata) {
  43. cfg->scale = pdata->scale;
  44. cfg->num = pdata->num;
  45. cfg->iout = pdata->iout_code;
  46. }
  47. led->isink_num = cfg->num;
  48. /* scale configuration */
  49. addr = LP8788_ISINK_CTRL;
  50. mask = 1 << (cfg->num + LP8788_ISINK_SCALE_OFFSET);
  51. val = cfg->scale << (cfg->num + LP8788_ISINK_SCALE_OFFSET);
  52. ret = lp8788_update_bits(led->lp, addr, mask, val);
  53. if (ret)
  54. return ret;
  55. /* current configuration */
  56. addr = lp8788_iout_addr[cfg->num];
  57. mask = lp8788_iout_mask[cfg->num];
  58. val = cfg->iout;
  59. return lp8788_update_bits(led->lp, addr, mask, val);
  60. }
  61. static int lp8788_led_enable(struct lp8788_led *led,
  62. enum lp8788_isink_number num, int on)
  63. {
  64. int ret;
  65. u8 mask = 1 << num;
  66. u8 val = on << num;
  67. ret = lp8788_update_bits(led->lp, LP8788_ISINK_CTRL, mask, val);
  68. if (ret == 0)
  69. led->on = on;
  70. return ret;
  71. }
  72. static int lp8788_brightness_set(struct led_classdev *led_cdev,
  73. enum led_brightness val)
  74. {
  75. struct lp8788_led *led =
  76. container_of(led_cdev, struct lp8788_led, led_dev);
  77. enum lp8788_isink_number num = led->isink_num;
  78. int enable, ret;
  79. mutex_lock(&led->lock);
  80. switch (num) {
  81. case LP8788_ISINK_1:
  82. case LP8788_ISINK_2:
  83. case LP8788_ISINK_3:
  84. ret = lp8788_write_byte(led->lp, lp8788_pwm_addr[num], val);
  85. if (ret < 0)
  86. goto unlock;
  87. break;
  88. default:
  89. mutex_unlock(&led->lock);
  90. return -EINVAL;
  91. }
  92. enable = (val > 0) ? 1 : 0;
  93. if (enable != led->on)
  94. ret = lp8788_led_enable(led, num, enable);
  95. unlock:
  96. mutex_unlock(&led->lock);
  97. return ret;
  98. }
  99. static int lp8788_led_probe(struct platform_device *pdev)
  100. {
  101. struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent);
  102. struct lp8788_led_platform_data *led_pdata;
  103. struct lp8788_led *led;
  104. struct device *dev = &pdev->dev;
  105. int ret;
  106. led = devm_kzalloc(dev, sizeof(struct lp8788_led), GFP_KERNEL);
  107. if (!led)
  108. return -ENOMEM;
  109. led->lp = lp;
  110. led->led_dev.max_brightness = MAX_BRIGHTNESS;
  111. led->led_dev.brightness_set_blocking = lp8788_brightness_set;
  112. led_pdata = lp->pdata ? lp->pdata->led_pdata : NULL;
  113. if (!led_pdata || !led_pdata->name)
  114. led->led_dev.name = DEFAULT_LED_NAME;
  115. else
  116. led->led_dev.name = led_pdata->name;
  117. mutex_init(&led->lock);
  118. ret = lp8788_led_init_device(led, led_pdata);
  119. if (ret) {
  120. dev_err(dev, "led init device err: %d\n", ret);
  121. return ret;
  122. }
  123. ret = devm_led_classdev_register(dev, &led->led_dev);
  124. if (ret) {
  125. dev_err(dev, "led register err: %d\n", ret);
  126. return ret;
  127. }
  128. return 0;
  129. }
  130. static struct platform_driver lp8788_led_driver = {
  131. .probe = lp8788_led_probe,
  132. .driver = {
  133. .name = LP8788_DEV_KEYLED,
  134. },
  135. };
  136. module_platform_driver(lp8788_led_driver);
  137. MODULE_DESCRIPTION("Texas Instruments LP8788 Keyboard LED Driver");
  138. MODULE_AUTHOR("Milo Kim");
  139. MODULE_LICENSE("GPL");
  140. MODULE_ALIAS("platform:lp8788-keyled");