led_bcm6358.c 4.5 KB

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  1. // SPDX-License-Identifier: GPL-2.0+
  2. /*
  3. * Copyright (C) 2017 Álvaro Fernández Rojas <noltari@gmail.com>
  4. */
  5. #include <common.h>
  6. #include <dm.h>
  7. #include <errno.h>
  8. #include <led.h>
  9. #include <log.h>
  10. #include <asm/io.h>
  11. #include <dm/lists.h>
  12. #include <linux/delay.h>
  13. #define LEDS_MAX 32
  14. #define LEDS_WAIT 100
  15. /* LED Mode register */
  16. #define LED_MODE_REG 0x0
  17. #define LED_MODE_OFF 0
  18. #define LED_MODE_ON 1
  19. #define LED_MODE_MASK 1
  20. /* LED Control register */
  21. #define LED_CTRL_REG 0x4
  22. #define LED_CTRL_CLK_MASK 0x3
  23. #define LED_CTRL_CLK_1 0
  24. #define LED_CTRL_CLK_2 1
  25. #define LED_CTRL_CLK_4 2
  26. #define LED_CTRL_CLK_8 3
  27. #define LED_CTRL_POL_SHIFT 2
  28. #define LED_CTRL_POL_MASK (1 << LED_CTRL_POL_SHIFT)
  29. #define LED_CTRL_BUSY_SHIFT 3
  30. #define LED_CTRL_BUSY_MASK (1 << LED_CTRL_BUSY_SHIFT)
  31. struct bcm6358_led_priv {
  32. void __iomem *regs;
  33. uint8_t pin;
  34. bool active_low;
  35. };
  36. static void bcm6358_led_busy(void __iomem *regs)
  37. {
  38. while (readl_be(regs + LED_CTRL_REG) & LED_CTRL_BUSY_MASK)
  39. udelay(LEDS_WAIT);
  40. }
  41. static unsigned long bcm6358_led_get_mode(struct bcm6358_led_priv *priv)
  42. {
  43. bcm6358_led_busy(priv->regs);
  44. return (readl_be(priv->regs + LED_MODE_REG) >> priv->pin) &
  45. LED_MODE_MASK;
  46. }
  47. static int bcm6358_led_set_mode(struct bcm6358_led_priv *priv, uint8_t mode)
  48. {
  49. bcm6358_led_busy(priv->regs);
  50. clrsetbits_be32(priv->regs + LED_MODE_REG,
  51. (LED_MODE_MASK << priv->pin),
  52. (mode << priv->pin));
  53. return 0;
  54. }
  55. static enum led_state_t bcm6358_led_get_state(struct udevice *dev)
  56. {
  57. struct bcm6358_led_priv *priv = dev_get_priv(dev);
  58. enum led_state_t state = LEDST_OFF;
  59. switch (bcm6358_led_get_mode(priv)) {
  60. case LED_MODE_OFF:
  61. state = (priv->active_low ? LEDST_ON : LEDST_OFF);
  62. break;
  63. case LED_MODE_ON:
  64. state = (priv->active_low ? LEDST_OFF : LEDST_ON);
  65. break;
  66. }
  67. return state;
  68. }
  69. static int bcm6358_led_set_state(struct udevice *dev, enum led_state_t state)
  70. {
  71. struct bcm6358_led_priv *priv = dev_get_priv(dev);
  72. unsigned long mode;
  73. switch (state) {
  74. case LEDST_OFF:
  75. mode = (priv->active_low ? LED_MODE_ON : LED_MODE_OFF);
  76. break;
  77. case LEDST_ON:
  78. mode = (priv->active_low ? LED_MODE_OFF : LED_MODE_ON);
  79. break;
  80. case LEDST_TOGGLE:
  81. if (bcm6358_led_get_state(dev) == LEDST_OFF)
  82. return bcm6358_led_set_state(dev, LEDST_ON);
  83. else
  84. return bcm6358_led_set_state(dev, LEDST_OFF);
  85. break;
  86. default:
  87. return -ENOSYS;
  88. }
  89. return bcm6358_led_set_mode(priv, mode);
  90. }
  91. static const struct led_ops bcm6358_led_ops = {
  92. .get_state = bcm6358_led_get_state,
  93. .set_state = bcm6358_led_set_state,
  94. };
  95. static int bcm6358_led_probe(struct udevice *dev)
  96. {
  97. struct led_uc_plat *uc_plat = dev_get_uclass_platdata(dev);
  98. /* Top-level LED node */
  99. if (!uc_plat->label) {
  100. void __iomem *regs;
  101. unsigned int clk_div;
  102. u32 set_bits = 0;
  103. regs = dev_remap_addr(dev);
  104. if (!regs)
  105. return -EINVAL;
  106. if (dev_read_bool(dev, "brcm,clk-dat-low"))
  107. set_bits |= LED_CTRL_POL_MASK;
  108. clk_div = dev_read_u32_default(dev, "brcm,clk-div",
  109. LED_CTRL_CLK_1);
  110. switch (clk_div) {
  111. case 8:
  112. set_bits |= LED_CTRL_CLK_8;
  113. break;
  114. case 4:
  115. set_bits |= LED_CTRL_CLK_4;
  116. break;
  117. case 2:
  118. set_bits |= LED_CTRL_CLK_2;
  119. break;
  120. default:
  121. set_bits |= LED_CTRL_CLK_1;
  122. break;
  123. }
  124. bcm6358_led_busy(regs);
  125. clrsetbits_be32(regs + LED_CTRL_REG,
  126. LED_CTRL_POL_MASK | LED_CTRL_CLK_MASK,
  127. set_bits);
  128. } else {
  129. struct bcm6358_led_priv *priv = dev_get_priv(dev);
  130. unsigned int pin;
  131. priv->regs = dev_remap_addr(dev);
  132. if (!priv->regs)
  133. return -EINVAL;
  134. pin = dev_read_u32_default(dev, "reg", LEDS_MAX);
  135. if (pin >= LEDS_MAX)
  136. return -EINVAL;
  137. priv->pin = pin;
  138. if (dev_read_bool(dev, "active-low"))
  139. priv->active_low = true;
  140. }
  141. return 0;
  142. }
  143. static int bcm6358_led_bind(struct udevice *parent)
  144. {
  145. ofnode node;
  146. dev_for_each_subnode(node, parent) {
  147. struct led_uc_plat *uc_plat;
  148. struct udevice *dev;
  149. const char *label;
  150. int ret;
  151. label = ofnode_read_string(node, "label");
  152. if (!label) {
  153. debug("%s: node %s has no label\n", __func__,
  154. ofnode_get_name(node));
  155. return -EINVAL;
  156. }
  157. ret = device_bind_driver_to_node(parent, "bcm6358-led",
  158. ofnode_get_name(node),
  159. node, &dev);
  160. if (ret)
  161. return ret;
  162. uc_plat = dev_get_uclass_platdata(dev);
  163. uc_plat->label = label;
  164. }
  165. return 0;
  166. }
  167. static const struct udevice_id bcm6358_led_ids[] = {
  168. { .compatible = "brcm,bcm6358-leds" },
  169. { /* sentinel */ }
  170. };
  171. U_BOOT_DRIVER(bcm6358_led) = {
  172. .name = "bcm6358-led",
  173. .id = UCLASS_LED,
  174. .of_match = bcm6358_led_ids,
  175. .bind = bcm6358_led_bind,
  176. .probe = bcm6358_led_probe,
  177. .priv_auto_alloc_size = sizeof(struct bcm6358_led_priv),
  178. .ops = &bcm6358_led_ops,
  179. };