gpio-menz127.c 4.9 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * MEN 16Z127 GPIO driver
  4. *
  5. * Copyright (C) 2016 MEN Mikroelektronik GmbH (www.men.de)
  6. */
  7. #include <linux/kernel.h>
  8. #include <linux/module.h>
  9. #include <linux/io.h>
  10. #include <linux/err.h>
  11. #include <linux/mcb.h>
  12. #include <linux/bitops.h>
  13. #include <linux/gpio/driver.h>
  14. #define MEN_Z127_CTRL 0x00
  15. #define MEN_Z127_PSR 0x04
  16. #define MEN_Z127_IRQR 0x08
  17. #define MEN_Z127_GPIODR 0x0c
  18. #define MEN_Z127_IER1 0x10
  19. #define MEN_Z127_IER2 0x14
  20. #define MEN_Z127_DBER 0x18
  21. #define MEN_Z127_ODER 0x1C
  22. #define GPIO_TO_DBCNT_REG(gpio) ((gpio * 4) + 0x80)
  23. #define MEN_Z127_DB_MIN_US 50
  24. /* 16 bit compare register. Each bit represents 50us */
  25. #define MEN_Z127_DB_MAX_US (0xffff * MEN_Z127_DB_MIN_US)
  26. #define MEN_Z127_DB_IN_RANGE(db) ((db >= MEN_Z127_DB_MIN_US) && \
  27. (db <= MEN_Z127_DB_MAX_US))
  28. struct men_z127_gpio {
  29. struct gpio_chip gc;
  30. void __iomem *reg_base;
  31. struct resource *mem;
  32. };
  33. static int men_z127_debounce(struct gpio_chip *gc, unsigned gpio,
  34. unsigned debounce)
  35. {
  36. struct men_z127_gpio *priv = gpiochip_get_data(gc);
  37. struct device *dev = gc->parent;
  38. unsigned int rnd;
  39. u32 db_en, db_cnt;
  40. if (!MEN_Z127_DB_IN_RANGE(debounce)) {
  41. dev_err(dev, "debounce value %u out of range", debounce);
  42. return -EINVAL;
  43. }
  44. if (debounce > 0) {
  45. /* round up or down depending on MSB-1 */
  46. rnd = fls(debounce) - 1;
  47. if (rnd && (debounce & BIT(rnd - 1)))
  48. debounce = roundup(debounce, MEN_Z127_DB_MIN_US);
  49. else
  50. debounce = rounddown(debounce, MEN_Z127_DB_MIN_US);
  51. if (debounce > MEN_Z127_DB_MAX_US)
  52. debounce = MEN_Z127_DB_MAX_US;
  53. /* 50us per register unit */
  54. debounce /= 50;
  55. }
  56. spin_lock(&gc->bgpio_lock);
  57. db_en = readl(priv->reg_base + MEN_Z127_DBER);
  58. if (debounce == 0) {
  59. db_en &= ~BIT(gpio);
  60. db_cnt = 0;
  61. } else {
  62. db_en |= BIT(gpio);
  63. db_cnt = debounce;
  64. }
  65. writel(db_en, priv->reg_base + MEN_Z127_DBER);
  66. writel(db_cnt, priv->reg_base + GPIO_TO_DBCNT_REG(gpio));
  67. spin_unlock(&gc->bgpio_lock);
  68. return 0;
  69. }
  70. static int men_z127_set_single_ended(struct gpio_chip *gc,
  71. unsigned offset,
  72. enum pin_config_param param)
  73. {
  74. struct men_z127_gpio *priv = gpiochip_get_data(gc);
  75. u32 od_en;
  76. spin_lock(&gc->bgpio_lock);
  77. od_en = readl(priv->reg_base + MEN_Z127_ODER);
  78. if (param == PIN_CONFIG_DRIVE_OPEN_DRAIN)
  79. od_en |= BIT(offset);
  80. else
  81. /* Implicitly PIN_CONFIG_DRIVE_PUSH_PULL */
  82. od_en &= ~BIT(offset);
  83. writel(od_en, priv->reg_base + MEN_Z127_ODER);
  84. spin_unlock(&gc->bgpio_lock);
  85. return 0;
  86. }
  87. static int men_z127_set_config(struct gpio_chip *gc, unsigned offset,
  88. unsigned long config)
  89. {
  90. enum pin_config_param param = pinconf_to_config_param(config);
  91. switch (param) {
  92. case PIN_CONFIG_DRIVE_OPEN_DRAIN:
  93. case PIN_CONFIG_DRIVE_PUSH_PULL:
  94. return men_z127_set_single_ended(gc, offset, param);
  95. case PIN_CONFIG_INPUT_DEBOUNCE:
  96. return men_z127_debounce(gc, offset,
  97. pinconf_to_config_argument(config));
  98. default:
  99. break;
  100. }
  101. return -ENOTSUPP;
  102. }
  103. static int men_z127_probe(struct mcb_device *mdev,
  104. const struct mcb_device_id *id)
  105. {
  106. struct men_z127_gpio *men_z127_gpio;
  107. struct device *dev = &mdev->dev;
  108. int ret;
  109. men_z127_gpio = devm_kzalloc(dev, sizeof(struct men_z127_gpio),
  110. GFP_KERNEL);
  111. if (!men_z127_gpio)
  112. return -ENOMEM;
  113. men_z127_gpio->mem = mcb_request_mem(mdev, dev_name(dev));
  114. if (IS_ERR(men_z127_gpio->mem)) {
  115. dev_err(dev, "failed to request device memory");
  116. return PTR_ERR(men_z127_gpio->mem);
  117. }
  118. men_z127_gpio->reg_base = ioremap(men_z127_gpio->mem->start,
  119. resource_size(men_z127_gpio->mem));
  120. if (men_z127_gpio->reg_base == NULL) {
  121. ret = -ENXIO;
  122. goto err_release;
  123. }
  124. mcb_set_drvdata(mdev, men_z127_gpio);
  125. ret = bgpio_init(&men_z127_gpio->gc, &mdev->dev, 4,
  126. men_z127_gpio->reg_base + MEN_Z127_PSR,
  127. men_z127_gpio->reg_base + MEN_Z127_CTRL,
  128. NULL,
  129. men_z127_gpio->reg_base + MEN_Z127_GPIODR,
  130. NULL, 0);
  131. if (ret)
  132. goto err_unmap;
  133. men_z127_gpio->gc.set_config = men_z127_set_config;
  134. ret = gpiochip_add_data(&men_z127_gpio->gc, men_z127_gpio);
  135. if (ret) {
  136. dev_err(dev, "failed to register MEN 16Z127 GPIO controller");
  137. goto err_unmap;
  138. }
  139. dev_info(dev, "MEN 16Z127 GPIO driver registered");
  140. return 0;
  141. err_unmap:
  142. iounmap(men_z127_gpio->reg_base);
  143. err_release:
  144. mcb_release_mem(men_z127_gpio->mem);
  145. return ret;
  146. }
  147. static void men_z127_remove(struct mcb_device *mdev)
  148. {
  149. struct men_z127_gpio *men_z127_gpio = mcb_get_drvdata(mdev);
  150. gpiochip_remove(&men_z127_gpio->gc);
  151. iounmap(men_z127_gpio->reg_base);
  152. mcb_release_mem(men_z127_gpio->mem);
  153. }
  154. static const struct mcb_device_id men_z127_ids[] = {
  155. { .device = 0x7f },
  156. { }
  157. };
  158. MODULE_DEVICE_TABLE(mcb, men_z127_ids);
  159. static struct mcb_driver men_z127_driver = {
  160. .driver = {
  161. .name = "z127-gpio",
  162. },
  163. .probe = men_z127_probe,
  164. .remove = men_z127_remove,
  165. .id_table = men_z127_ids,
  166. };
  167. module_mcb_driver(men_z127_driver);
  168. MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
  169. MODULE_DESCRIPTION("MEN 16z127 GPIO Controller");
  170. MODULE_LICENSE("GPL v2");
  171. MODULE_ALIAS("mcb:16z127");
  172. MODULE_IMPORT_NS(MCB);