pinctrl-mcp23s08_spi.c 6.1 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /* MCP23S08 SPI GPIO driver */
  3. #include <linux/mod_devicetable.h>
  4. #include <linux/module.h>
  5. #include <linux/property.h>
  6. #include <linux/regmap.h>
  7. #include <linux/spi/spi.h>
  8. #include "pinctrl-mcp23s08.h"
  9. #define MCP_MAX_DEV_PER_CS 8
  10. /*
  11. * A given spi_device can represent up to eight mcp23sxx chips
  12. * sharing the same chipselect but using different addresses
  13. * (e.g. chips #0 and #3 might be populated, but not #1 or #2).
  14. * Driver data holds all the per-chip data.
  15. */
  16. struct mcp23s08_driver_data {
  17. unsigned ngpio;
  18. struct mcp23s08 *mcp[8];
  19. struct mcp23s08 chip[];
  20. };
  21. static int mcp23sxx_spi_write(void *context, const void *data, size_t count)
  22. {
  23. struct mcp23s08 *mcp = context;
  24. struct spi_device *spi = to_spi_device(mcp->dev);
  25. struct spi_message m;
  26. struct spi_transfer t[2] = { { .tx_buf = &mcp->addr, .len = 1, },
  27. { .tx_buf = data, .len = count, }, };
  28. spi_message_init(&m);
  29. spi_message_add_tail(&t[0], &m);
  30. spi_message_add_tail(&t[1], &m);
  31. return spi_sync(spi, &m);
  32. }
  33. static int mcp23sxx_spi_gather_write(void *context,
  34. const void *reg, size_t reg_size,
  35. const void *val, size_t val_size)
  36. {
  37. struct mcp23s08 *mcp = context;
  38. struct spi_device *spi = to_spi_device(mcp->dev);
  39. struct spi_message m;
  40. struct spi_transfer t[3] = { { .tx_buf = &mcp->addr, .len = 1, },
  41. { .tx_buf = reg, .len = reg_size, },
  42. { .tx_buf = val, .len = val_size, }, };
  43. spi_message_init(&m);
  44. spi_message_add_tail(&t[0], &m);
  45. spi_message_add_tail(&t[1], &m);
  46. spi_message_add_tail(&t[2], &m);
  47. return spi_sync(spi, &m);
  48. }
  49. static int mcp23sxx_spi_read(void *context, const void *reg, size_t reg_size,
  50. void *val, size_t val_size)
  51. {
  52. struct mcp23s08 *mcp = context;
  53. struct spi_device *spi = to_spi_device(mcp->dev);
  54. u8 tx[2];
  55. if (reg_size != 1)
  56. return -EINVAL;
  57. tx[0] = mcp->addr | 0x01;
  58. tx[1] = *((u8 *) reg);
  59. return spi_write_then_read(spi, tx, sizeof(tx), val, val_size);
  60. }
  61. static const struct regmap_bus mcp23sxx_spi_regmap = {
  62. .write = mcp23sxx_spi_write,
  63. .gather_write = mcp23sxx_spi_gather_write,
  64. .read = mcp23sxx_spi_read,
  65. };
  66. static int mcp23s08_spi_regmap_init(struct mcp23s08 *mcp, struct device *dev,
  67. unsigned int addr, unsigned int type)
  68. {
  69. const struct regmap_config *config;
  70. struct regmap_config *copy;
  71. const char *name;
  72. switch (type) {
  73. case MCP_TYPE_S08:
  74. mcp->reg_shift = 0;
  75. mcp->chip.ngpio = 8;
  76. mcp->chip.label = devm_kasprintf(dev, GFP_KERNEL, "mcp23s08.%d", addr);
  77. config = &mcp23x08_regmap;
  78. name = devm_kasprintf(dev, GFP_KERNEL, "%d", addr);
  79. break;
  80. case MCP_TYPE_S17:
  81. mcp->reg_shift = 1;
  82. mcp->chip.ngpio = 16;
  83. mcp->chip.label = devm_kasprintf(dev, GFP_KERNEL, "mcp23s17.%d", addr);
  84. config = &mcp23x17_regmap;
  85. name = devm_kasprintf(dev, GFP_KERNEL, "%d", addr);
  86. break;
  87. case MCP_TYPE_S18:
  88. mcp->reg_shift = 1;
  89. mcp->chip.ngpio = 16;
  90. mcp->chip.label = "mcp23s18";
  91. config = &mcp23x17_regmap;
  92. name = config->name;
  93. break;
  94. default:
  95. dev_err(dev, "invalid device type (%d)\n", type);
  96. return -EINVAL;
  97. }
  98. copy = devm_kmemdup(dev, config, sizeof(*config), GFP_KERNEL);
  99. if (!copy)
  100. return -ENOMEM;
  101. copy->name = name;
  102. mcp->regmap = devm_regmap_init(dev, &mcp23sxx_spi_regmap, mcp, copy);
  103. if (IS_ERR(mcp->regmap))
  104. dev_err(dev, "regmap init failed for %s\n", mcp->chip.label);
  105. return PTR_ERR_OR_ZERO(mcp->regmap);
  106. }
  107. static int mcp23s08_probe(struct spi_device *spi)
  108. {
  109. struct device *dev = &spi->dev;
  110. struct mcp23s08_driver_data *data;
  111. unsigned long spi_present_mask;
  112. const void *match;
  113. unsigned int addr;
  114. unsigned int ngpio = 0;
  115. int chips;
  116. int type;
  117. int ret;
  118. u32 v;
  119. match = device_get_match_data(dev);
  120. if (match)
  121. type = (int)(uintptr_t)match;
  122. else
  123. type = spi_get_device_id(spi)->driver_data;
  124. ret = device_property_read_u32(dev, "microchip,spi-present-mask", &v);
  125. if (ret) {
  126. ret = device_property_read_u32(dev, "mcp,spi-present-mask", &v);
  127. if (ret) {
  128. dev_err(dev, "missing spi-present-mask");
  129. return ret;
  130. }
  131. }
  132. spi_present_mask = v;
  133. if (!spi_present_mask || spi_present_mask >= BIT(MCP_MAX_DEV_PER_CS)) {
  134. dev_err(dev, "invalid spi-present-mask");
  135. return -ENODEV;
  136. }
  137. chips = hweight_long(spi_present_mask);
  138. data = devm_kzalloc(dev, struct_size(data, chip, chips), GFP_KERNEL);
  139. if (!data)
  140. return -ENOMEM;
  141. spi_set_drvdata(spi, data);
  142. for_each_set_bit(addr, &spi_present_mask, MCP_MAX_DEV_PER_CS) {
  143. data->mcp[addr] = &data->chip[--chips];
  144. data->mcp[addr]->irq = spi->irq;
  145. ret = mcp23s08_spi_regmap_init(data->mcp[addr], dev, addr, type);
  146. if (ret)
  147. return ret;
  148. data->mcp[addr]->pinctrl_desc.name = devm_kasprintf(dev, GFP_KERNEL,
  149. "mcp23xxx-pinctrl.%d",
  150. addr);
  151. if (!data->mcp[addr]->pinctrl_desc.name)
  152. return -ENOMEM;
  153. ret = mcp23s08_probe_one(data->mcp[addr], dev, 0x40 | (addr << 1), type, -1);
  154. if (ret < 0)
  155. return ret;
  156. ngpio += data->mcp[addr]->chip.ngpio;
  157. }
  158. data->ngpio = ngpio;
  159. return 0;
  160. }
  161. static const struct spi_device_id mcp23s08_ids[] = {
  162. { "mcp23s08", MCP_TYPE_S08 },
  163. { "mcp23s17", MCP_TYPE_S17 },
  164. { "mcp23s18", MCP_TYPE_S18 },
  165. { }
  166. };
  167. MODULE_DEVICE_TABLE(spi, mcp23s08_ids);
  168. static const struct of_device_id mcp23s08_spi_of_match[] = {
  169. {
  170. .compatible = "microchip,mcp23s08",
  171. .data = (void *) MCP_TYPE_S08,
  172. },
  173. {
  174. .compatible = "microchip,mcp23s17",
  175. .data = (void *) MCP_TYPE_S17,
  176. },
  177. {
  178. .compatible = "microchip,mcp23s18",
  179. .data = (void *) MCP_TYPE_S18,
  180. },
  181. /* NOTE: The use of the mcp prefix is deprecated and will be removed. */
  182. {
  183. .compatible = "mcp,mcp23s08",
  184. .data = (void *) MCP_TYPE_S08,
  185. },
  186. {
  187. .compatible = "mcp,mcp23s17",
  188. .data = (void *) MCP_TYPE_S17,
  189. },
  190. { }
  191. };
  192. MODULE_DEVICE_TABLE(of, mcp23s08_spi_of_match);
  193. static struct spi_driver mcp23s08_driver = {
  194. .probe = mcp23s08_probe,
  195. .id_table = mcp23s08_ids,
  196. .driver = {
  197. .name = "mcp23s08",
  198. .of_match_table = mcp23s08_spi_of_match,
  199. },
  200. };
  201. static int __init mcp23s08_spi_init(void)
  202. {
  203. return spi_register_driver(&mcp23s08_driver);
  204. }
  205. /*
  206. * Register after SPI postcore initcall and before
  207. * subsys initcalls that may rely on these GPIOs.
  208. */
  209. subsys_initcall(mcp23s08_spi_init);
  210. static void mcp23s08_spi_exit(void)
  211. {
  212. spi_unregister_driver(&mcp23s08_driver);
  213. }
  214. module_exit(mcp23s08_spi_exit);
  215. MODULE_LICENSE("GPL");