i2c.c 6.2 KB

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  1. // SPDX-License-Identifier: GPL-2.0-or-later
  2. /*
  3. * I2C Link Layer for Samsung S3FWRN5 NCI based Driver
  4. *
  5. * Copyright (C) 2015 Samsung Electrnoics
  6. * Robert Baldyga <r.baldyga@samsung.com>
  7. */
  8. #include <linux/i2c.h>
  9. #include <linux/gpio.h>
  10. #include <linux/delay.h>
  11. #include <linux/of_gpio.h>
  12. #include <linux/of_irq.h>
  13. #include <linux/module.h>
  14. #include <net/nfc/nfc.h>
  15. #include "s3fwrn5.h"
  16. #define S3FWRN5_I2C_DRIVER_NAME "s3fwrn5_i2c"
  17. #define S3FWRN5_I2C_MAX_PAYLOAD 32
  18. #define S3FWRN5_EN_WAIT_TIME 150
  19. struct s3fwrn5_i2c_phy {
  20. struct i2c_client *i2c_dev;
  21. struct nci_dev *ndev;
  22. int gpio_en;
  23. int gpio_fw_wake;
  24. struct mutex mutex;
  25. enum s3fwrn5_mode mode;
  26. unsigned int irq_skip:1;
  27. };
  28. static void s3fwrn5_i2c_set_wake(void *phy_id, bool wake)
  29. {
  30. struct s3fwrn5_i2c_phy *phy = phy_id;
  31. mutex_lock(&phy->mutex);
  32. gpio_set_value(phy->gpio_fw_wake, wake);
  33. msleep(S3FWRN5_EN_WAIT_TIME/2);
  34. mutex_unlock(&phy->mutex);
  35. }
  36. static void s3fwrn5_i2c_set_mode(void *phy_id, enum s3fwrn5_mode mode)
  37. {
  38. struct s3fwrn5_i2c_phy *phy = phy_id;
  39. mutex_lock(&phy->mutex);
  40. if (phy->mode == mode)
  41. goto out;
  42. phy->mode = mode;
  43. gpio_set_value(phy->gpio_en, 1);
  44. gpio_set_value(phy->gpio_fw_wake, 0);
  45. if (mode == S3FWRN5_MODE_FW)
  46. gpio_set_value(phy->gpio_fw_wake, 1);
  47. if (mode != S3FWRN5_MODE_COLD) {
  48. msleep(S3FWRN5_EN_WAIT_TIME);
  49. gpio_set_value(phy->gpio_en, 0);
  50. msleep(S3FWRN5_EN_WAIT_TIME/2);
  51. }
  52. phy->irq_skip = true;
  53. out:
  54. mutex_unlock(&phy->mutex);
  55. }
  56. static enum s3fwrn5_mode s3fwrn5_i2c_get_mode(void *phy_id)
  57. {
  58. struct s3fwrn5_i2c_phy *phy = phy_id;
  59. enum s3fwrn5_mode mode;
  60. mutex_lock(&phy->mutex);
  61. mode = phy->mode;
  62. mutex_unlock(&phy->mutex);
  63. return mode;
  64. }
  65. static int s3fwrn5_i2c_write(void *phy_id, struct sk_buff *skb)
  66. {
  67. struct s3fwrn5_i2c_phy *phy = phy_id;
  68. int ret;
  69. mutex_lock(&phy->mutex);
  70. phy->irq_skip = false;
  71. ret = i2c_master_send(phy->i2c_dev, skb->data, skb->len);
  72. if (ret == -EREMOTEIO) {
  73. /* Retry, chip was in standby */
  74. usleep_range(110000, 120000);
  75. ret = i2c_master_send(phy->i2c_dev, skb->data, skb->len);
  76. }
  77. mutex_unlock(&phy->mutex);
  78. if (ret < 0)
  79. return ret;
  80. if (ret != skb->len)
  81. return -EREMOTEIO;
  82. return 0;
  83. }
  84. static const struct s3fwrn5_phy_ops i2c_phy_ops = {
  85. .set_wake = s3fwrn5_i2c_set_wake,
  86. .set_mode = s3fwrn5_i2c_set_mode,
  87. .get_mode = s3fwrn5_i2c_get_mode,
  88. .write = s3fwrn5_i2c_write,
  89. };
  90. static int s3fwrn5_i2c_read(struct s3fwrn5_i2c_phy *phy)
  91. {
  92. struct sk_buff *skb;
  93. size_t hdr_size;
  94. size_t data_len;
  95. char hdr[4];
  96. int ret;
  97. hdr_size = (phy->mode == S3FWRN5_MODE_NCI) ?
  98. NCI_CTRL_HDR_SIZE : S3FWRN5_FW_HDR_SIZE;
  99. ret = i2c_master_recv(phy->i2c_dev, hdr, hdr_size);
  100. if (ret < 0)
  101. return ret;
  102. if (ret < hdr_size)
  103. return -EBADMSG;
  104. data_len = (phy->mode == S3FWRN5_MODE_NCI) ?
  105. ((struct nci_ctrl_hdr *)hdr)->plen :
  106. ((struct s3fwrn5_fw_header *)hdr)->len;
  107. skb = alloc_skb(hdr_size + data_len, GFP_KERNEL);
  108. if (!skb)
  109. return -ENOMEM;
  110. skb_put_data(skb, hdr, hdr_size);
  111. if (data_len == 0)
  112. goto out;
  113. ret = i2c_master_recv(phy->i2c_dev, skb_put(skb, data_len), data_len);
  114. if (ret != data_len) {
  115. kfree_skb(skb);
  116. return -EBADMSG;
  117. }
  118. out:
  119. return s3fwrn5_recv_frame(phy->ndev, skb, phy->mode);
  120. }
  121. static irqreturn_t s3fwrn5_i2c_irq_thread_fn(int irq, void *phy_id)
  122. {
  123. struct s3fwrn5_i2c_phy *phy = phy_id;
  124. if (!phy || !phy->ndev) {
  125. WARN_ON_ONCE(1);
  126. return IRQ_NONE;
  127. }
  128. mutex_lock(&phy->mutex);
  129. if (phy->irq_skip)
  130. goto out;
  131. switch (phy->mode) {
  132. case S3FWRN5_MODE_NCI:
  133. case S3FWRN5_MODE_FW:
  134. s3fwrn5_i2c_read(phy);
  135. break;
  136. case S3FWRN5_MODE_COLD:
  137. break;
  138. }
  139. out:
  140. mutex_unlock(&phy->mutex);
  141. return IRQ_HANDLED;
  142. }
  143. static int s3fwrn5_i2c_parse_dt(struct i2c_client *client)
  144. {
  145. struct s3fwrn5_i2c_phy *phy = i2c_get_clientdata(client);
  146. struct device_node *np = client->dev.of_node;
  147. if (!np)
  148. return -ENODEV;
  149. phy->gpio_en = of_get_named_gpio(np, "en-gpios", 0);
  150. if (!gpio_is_valid(phy->gpio_en)) {
  151. /* Support also deprecated property */
  152. phy->gpio_en = of_get_named_gpio(np, "s3fwrn5,en-gpios", 0);
  153. if (!gpio_is_valid(phy->gpio_en))
  154. return -ENODEV;
  155. }
  156. phy->gpio_fw_wake = of_get_named_gpio(np, "wake-gpios", 0);
  157. if (!gpio_is_valid(phy->gpio_fw_wake)) {
  158. /* Support also deprecated property */
  159. phy->gpio_fw_wake = of_get_named_gpio(np, "s3fwrn5,fw-gpios", 0);
  160. if (!gpio_is_valid(phy->gpio_fw_wake))
  161. return -ENODEV;
  162. }
  163. return 0;
  164. }
  165. static int s3fwrn5_i2c_probe(struct i2c_client *client,
  166. const struct i2c_device_id *id)
  167. {
  168. struct s3fwrn5_i2c_phy *phy;
  169. int ret;
  170. phy = devm_kzalloc(&client->dev, sizeof(*phy), GFP_KERNEL);
  171. if (!phy)
  172. return -ENOMEM;
  173. mutex_init(&phy->mutex);
  174. phy->mode = S3FWRN5_MODE_COLD;
  175. phy->irq_skip = true;
  176. phy->i2c_dev = client;
  177. i2c_set_clientdata(client, phy);
  178. ret = s3fwrn5_i2c_parse_dt(client);
  179. if (ret < 0)
  180. return ret;
  181. ret = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_en,
  182. GPIOF_OUT_INIT_HIGH, "s3fwrn5_en");
  183. if (ret < 0)
  184. return ret;
  185. ret = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_fw_wake,
  186. GPIOF_OUT_INIT_LOW, "s3fwrn5_fw_wake");
  187. if (ret < 0)
  188. return ret;
  189. ret = s3fwrn5_probe(&phy->ndev, phy, &phy->i2c_dev->dev, &i2c_phy_ops,
  190. S3FWRN5_I2C_MAX_PAYLOAD);
  191. if (ret < 0)
  192. return ret;
  193. ret = devm_request_threaded_irq(&client->dev, phy->i2c_dev->irq, NULL,
  194. s3fwrn5_i2c_irq_thread_fn, IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
  195. S3FWRN5_I2C_DRIVER_NAME, phy);
  196. if (ret)
  197. s3fwrn5_remove(phy->ndev);
  198. return ret;
  199. }
  200. static int s3fwrn5_i2c_remove(struct i2c_client *client)
  201. {
  202. struct s3fwrn5_i2c_phy *phy = i2c_get_clientdata(client);
  203. s3fwrn5_remove(phy->ndev);
  204. return 0;
  205. }
  206. static const struct i2c_device_id s3fwrn5_i2c_id_table[] = {
  207. {S3FWRN5_I2C_DRIVER_NAME, 0},
  208. {}
  209. };
  210. MODULE_DEVICE_TABLE(i2c, s3fwrn5_i2c_id_table);
  211. static const struct of_device_id of_s3fwrn5_i2c_match[] = {
  212. { .compatible = "samsung,s3fwrn5-i2c", },
  213. {}
  214. };
  215. MODULE_DEVICE_TABLE(of, of_s3fwrn5_i2c_match);
  216. static struct i2c_driver s3fwrn5_i2c_driver = {
  217. .driver = {
  218. .name = S3FWRN5_I2C_DRIVER_NAME,
  219. .of_match_table = of_match_ptr(of_s3fwrn5_i2c_match),
  220. },
  221. .probe = s3fwrn5_i2c_probe,
  222. .remove = s3fwrn5_i2c_remove,
  223. .id_table = s3fwrn5_i2c_id_table,
  224. };
  225. module_i2c_driver(s3fwrn5_i2c_driver);
  226. MODULE_LICENSE("GPL");
  227. MODULE_DESCRIPTION("I2C driver for Samsung S3FWRN5");
  228. MODULE_AUTHOR("Robert Baldyga <r.baldyga@samsung.com>");