mcp230xx_gpio.c 5.3 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * Copyright (C) 2021, Collabora Ltd.
  4. * Copyright (C) 2021, General Electric Company
  5. * Author(s): Sebastian Reichel <sebastian.reichel@collabora.com>
  6. */
  7. #define LOG_CATEGORY UCLASS_GPIO
  8. #include <common.h>
  9. #include <errno.h>
  10. #include <dm.h>
  11. #include <i2c.h>
  12. #include <asm/gpio.h>
  13. #include <dm/device_compat.h>
  14. #include <dt-bindings/gpio/gpio.h>
  15. enum mcp230xx_type {
  16. UNKNOWN = 0,
  17. MCP23008,
  18. MCP23017,
  19. MCP23018,
  20. };
  21. #define MCP230XX_IODIR 0x00
  22. #define MCP230XX_GPPU 0x06
  23. #define MCP230XX_GPIO 0x09
  24. #define MCP230XX_OLAT 0x0a
  25. #define BANKSIZE 8
  26. static int mcp230xx_read(struct udevice *dev, uint reg, uint offset)
  27. {
  28. struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
  29. int bank = offset / BANKSIZE;
  30. int mask = 1 << (offset % BANKSIZE);
  31. int shift = (uc_priv->gpio_count / BANKSIZE) - 1;
  32. int ret;
  33. ret = dm_i2c_reg_read(dev, (reg << shift) | bank);
  34. if (ret < 0)
  35. return ret;
  36. return !!(ret & mask);
  37. }
  38. static int mcp230xx_write(struct udevice *dev, uint reg, uint offset, bool val)
  39. {
  40. struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
  41. int bank = offset / BANKSIZE;
  42. int mask = 1 << (offset % BANKSIZE);
  43. int shift = (uc_priv->gpio_count / BANKSIZE) - 1;
  44. return dm_i2c_reg_clrset(dev, (reg << shift) | bank, mask, val ? mask : 0);
  45. }
  46. static int mcp230xx_get_value(struct udevice *dev, uint offset)
  47. {
  48. int ret;
  49. ret = mcp230xx_read(dev, MCP230XX_GPIO, offset);
  50. if (ret < 0) {
  51. dev_err(dev, "%s error: %d\n", __func__, ret);
  52. return ret;
  53. }
  54. return ret;
  55. }
  56. static int mcp230xx_set_value(struct udevice *dev, uint offset, int val)
  57. {
  58. int ret;
  59. ret = mcp230xx_write(dev, MCP230XX_GPIO, offset, val);
  60. if (ret < 0) {
  61. dev_err(dev, "%s error: %d\n", __func__, ret);
  62. return ret;
  63. }
  64. return ret;
  65. }
  66. static int mcp230xx_get_flags(struct udevice *dev, unsigned int offset,
  67. ulong *flags)
  68. {
  69. int direction, pullup;
  70. pullup = mcp230xx_read(dev, MCP230XX_GPPU, offset);
  71. if (pullup < 0) {
  72. dev_err(dev, "%s error: %d\n", __func__, pullup);
  73. return pullup;
  74. }
  75. direction = mcp230xx_read(dev, MCP230XX_IODIR, offset);
  76. if (direction < 0) {
  77. dev_err(dev, "%s error: %d\n", __func__, direction);
  78. return direction;
  79. }
  80. *flags = direction ? GPIOD_IS_IN : GPIOD_IS_OUT;
  81. if (pullup)
  82. *flags |= GPIOD_PULL_UP;
  83. return 0;
  84. }
  85. static int mcp230xx_set_flags(struct udevice *dev, uint offset, ulong flags)
  86. {
  87. bool input = !(flags & (GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE));
  88. bool pullup = flags & GPIOD_PULL_UP;
  89. ulong supported_mask;
  90. int ret;
  91. /* Note: active-low is ignored (handled by core) */
  92. supported_mask = GPIOD_ACTIVE_LOW | GPIOD_MASK_DIR | GPIOD_PULL_UP;
  93. if (flags & ~supported_mask) {
  94. dev_err(dev, "%s unsupported flag(s): %lx\n", __func__, flags);
  95. return -EINVAL;
  96. }
  97. ret = mcp230xx_write(dev, MCP230XX_OLAT, offset, !!(flags & GPIOD_IS_OUT_ACTIVE));
  98. if (ret) {
  99. dev_err(dev, "%s failed to setup output latch: %d\n", __func__, ret);
  100. return ret;
  101. }
  102. ret = mcp230xx_write(dev, MCP230XX_GPPU, offset, pullup);
  103. if (ret) {
  104. dev_err(dev, "%s failed to setup pull-up: %d\n", __func__, ret);
  105. return ret;
  106. }
  107. ret = mcp230xx_write(dev, MCP230XX_IODIR, offset, input);
  108. if (ret) {
  109. dev_err(dev, "%s failed to setup direction: %d\n", __func__, ret);
  110. return ret;
  111. }
  112. return 0;
  113. }
  114. static int mcp230xx_direction_input(struct udevice *dev, uint offset)
  115. {
  116. return mcp230xx_set_flags(dev, offset, GPIOD_IS_IN);
  117. }
  118. static int mcp230xx_direction_output(struct udevice *dev, uint offset, int val)
  119. {
  120. int ret = mcp230xx_set_value(dev, offset, val);
  121. if (ret < 0) {
  122. dev_err(dev, "%s error: %d\n", __func__, ret);
  123. return ret;
  124. }
  125. return mcp230xx_set_flags(dev, offset, GPIOD_IS_OUT);
  126. }
  127. static int mcp230xx_get_function(struct udevice *dev, uint offset)
  128. {
  129. int ret;
  130. ret = mcp230xx_read(dev, MCP230XX_IODIR, offset);
  131. if (ret < 0) {
  132. dev_err(dev, "%s error: %d\n", __func__, ret);
  133. return ret;
  134. }
  135. return ret ? GPIOF_INPUT : GPIOF_OUTPUT;
  136. }
  137. static const struct dm_gpio_ops mcp230xx_ops = {
  138. .direction_input = mcp230xx_direction_input,
  139. .direction_output = mcp230xx_direction_output,
  140. .get_value = mcp230xx_get_value,
  141. .set_value = mcp230xx_set_value,
  142. .get_function = mcp230xx_get_function,
  143. .set_flags = mcp230xx_set_flags,
  144. .get_flags = mcp230xx_get_flags,
  145. };
  146. static int mcp230xx_probe(struct udevice *dev)
  147. {
  148. struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
  149. char name[32], label[8], *str;
  150. int addr, gpio_count, size;
  151. const u8 *tmp;
  152. switch (dev_get_driver_data(dev)) {
  153. case MCP23008:
  154. gpio_count = 8;
  155. break;
  156. case MCP23017:
  157. case MCP23018:
  158. gpio_count = 16;
  159. break;
  160. default:
  161. return -ENODEV;
  162. }
  163. addr = dev_read_addr(dev);
  164. tmp = dev_read_prop(dev, "label", &size);
  165. if (tmp) {
  166. memcpy(label, tmp, sizeof(label) - 1);
  167. label[sizeof(label) - 1] = '\0';
  168. snprintf(name, sizeof(name), "%s@%x_", label, addr);
  169. } else {
  170. snprintf(name, sizeof(name), "gpio@%x_", addr);
  171. }
  172. str = strdup(name);
  173. if (!str)
  174. return -ENOMEM;
  175. uc_priv->bank_name = str;
  176. uc_priv->gpio_count = gpio_count;
  177. dev_dbg(dev, "%s is ready\n", str);
  178. return 0;
  179. }
  180. static const struct udevice_id mcp230xx_ids[] = {
  181. { .compatible = "microchip,mcp23008", .data = MCP23008, },
  182. { .compatible = "microchip,mcp23017", .data = MCP23017, },
  183. { .compatible = "microchip,mcp23018", .data = MCP23018, },
  184. { }
  185. };
  186. U_BOOT_DRIVER(mcp230xx) = {
  187. .name = "mcp230xx",
  188. .id = UCLASS_GPIO,
  189. .ops = &mcp230xx_ops,
  190. .probe = mcp230xx_probe,
  191. .of_match = mcp230xx_ids,
  192. };