spi-tle62x0.c 7.0 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * Support Infineon TLE62x0 driver chips
  4. *
  5. * Copyright (c) 2007 Simtec Electronics
  6. * Ben Dooks, <ben@simtec.co.uk>
  7. */
  8. #include <linux/device.h>
  9. #include <linux/kernel.h>
  10. #include <linux/module.h>
  11. #include <linux/slab.h>
  12. #include <linux/spi/spi.h>
  13. #include <linux/spi/tle62x0.h>
  14. #define CMD_READ 0x00
  15. #define CMD_SET 0xff
  16. #define DIAG_NORMAL 0x03
  17. #define DIAG_OVERLOAD 0x02
  18. #define DIAG_OPEN 0x01
  19. #define DIAG_SHORTGND 0x00
  20. struct tle62x0_state {
  21. struct spi_device *us;
  22. struct mutex lock;
  23. unsigned int nr_gpio;
  24. unsigned int gpio_state;
  25. unsigned char tx_buff[4];
  26. unsigned char rx_buff[4];
  27. };
  28. static int to_gpio_num(struct device_attribute *attr);
  29. static inline int tle62x0_write(struct tle62x0_state *st)
  30. {
  31. unsigned char *buff = st->tx_buff;
  32. unsigned int gpio_state = st->gpio_state;
  33. buff[0] = CMD_SET;
  34. if (st->nr_gpio == 16) {
  35. buff[1] = gpio_state >> 8;
  36. buff[2] = gpio_state;
  37. } else {
  38. buff[1] = gpio_state;
  39. }
  40. dev_dbg(&st->us->dev, "buff %3ph\n", buff);
  41. return spi_write(st->us, buff, (st->nr_gpio == 16) ? 3 : 2);
  42. }
  43. static inline int tle62x0_read(struct tle62x0_state *st)
  44. {
  45. unsigned char *txbuff = st->tx_buff;
  46. struct spi_transfer xfer = {
  47. .tx_buf = txbuff,
  48. .rx_buf = st->rx_buff,
  49. .len = (st->nr_gpio * 2) / 8,
  50. };
  51. struct spi_message msg;
  52. txbuff[0] = CMD_READ;
  53. txbuff[1] = 0x00;
  54. txbuff[2] = 0x00;
  55. txbuff[3] = 0x00;
  56. spi_message_init(&msg);
  57. spi_message_add_tail(&xfer, &msg);
  58. return spi_sync(st->us, &msg);
  59. }
  60. static unsigned char *decode_fault(unsigned int fault_code)
  61. {
  62. fault_code &= 3;
  63. switch (fault_code) {
  64. case DIAG_NORMAL:
  65. return "N";
  66. case DIAG_OVERLOAD:
  67. return "V";
  68. case DIAG_OPEN:
  69. return "O";
  70. case DIAG_SHORTGND:
  71. return "G";
  72. }
  73. return "?";
  74. }
  75. static ssize_t tle62x0_status_show(struct device *dev,
  76. struct device_attribute *attr, char *buf)
  77. {
  78. struct tle62x0_state *st = dev_get_drvdata(dev);
  79. char *bp = buf;
  80. unsigned char *buff = st->rx_buff;
  81. unsigned long fault = 0;
  82. int ptr;
  83. int ret;
  84. mutex_lock(&st->lock);
  85. ret = tle62x0_read(st);
  86. dev_dbg(dev, "tle62x0_read() returned %d\n", ret);
  87. if (ret < 0) {
  88. mutex_unlock(&st->lock);
  89. return ret;
  90. }
  91. for (ptr = 0; ptr < (st->nr_gpio * 2)/8; ptr += 1) {
  92. fault <<= 8;
  93. fault |= ((unsigned long)buff[ptr]);
  94. dev_dbg(dev, "byte %d is %02x\n", ptr, buff[ptr]);
  95. }
  96. for (ptr = 0; ptr < st->nr_gpio; ptr++) {
  97. bp += sprintf(bp, "%s ", decode_fault(fault >> (ptr * 2)));
  98. }
  99. *bp++ = '\n';
  100. mutex_unlock(&st->lock);
  101. return bp - buf;
  102. }
  103. static DEVICE_ATTR(status_show, S_IRUGO, tle62x0_status_show, NULL);
  104. static ssize_t tle62x0_gpio_show(struct device *dev,
  105. struct device_attribute *attr, char *buf)
  106. {
  107. struct tle62x0_state *st = dev_get_drvdata(dev);
  108. int gpio_num = to_gpio_num(attr);
  109. int value;
  110. mutex_lock(&st->lock);
  111. value = (st->gpio_state >> gpio_num) & 1;
  112. mutex_unlock(&st->lock);
  113. return snprintf(buf, PAGE_SIZE, "%d", value);
  114. }
  115. static ssize_t tle62x0_gpio_store(struct device *dev,
  116. struct device_attribute *attr,
  117. const char *buf, size_t len)
  118. {
  119. struct tle62x0_state *st = dev_get_drvdata(dev);
  120. int gpio_num = to_gpio_num(attr);
  121. unsigned long val;
  122. char *endp;
  123. val = simple_strtoul(buf, &endp, 0);
  124. if (buf == endp)
  125. return -EINVAL;
  126. dev_dbg(dev, "setting gpio %d to %ld\n", gpio_num, val);
  127. mutex_lock(&st->lock);
  128. if (val)
  129. st->gpio_state |= 1 << gpio_num;
  130. else
  131. st->gpio_state &= ~(1 << gpio_num);
  132. tle62x0_write(st);
  133. mutex_unlock(&st->lock);
  134. return len;
  135. }
  136. static DEVICE_ATTR(gpio1, S_IWUSR|S_IRUGO,
  137. tle62x0_gpio_show, tle62x0_gpio_store);
  138. static DEVICE_ATTR(gpio2, S_IWUSR|S_IRUGO,
  139. tle62x0_gpio_show, tle62x0_gpio_store);
  140. static DEVICE_ATTR(gpio3, S_IWUSR|S_IRUGO,
  141. tle62x0_gpio_show, tle62x0_gpio_store);
  142. static DEVICE_ATTR(gpio4, S_IWUSR|S_IRUGO,
  143. tle62x0_gpio_show, tle62x0_gpio_store);
  144. static DEVICE_ATTR(gpio5, S_IWUSR|S_IRUGO,
  145. tle62x0_gpio_show, tle62x0_gpio_store);
  146. static DEVICE_ATTR(gpio6, S_IWUSR|S_IRUGO,
  147. tle62x0_gpio_show, tle62x0_gpio_store);
  148. static DEVICE_ATTR(gpio7, S_IWUSR|S_IRUGO,
  149. tle62x0_gpio_show, tle62x0_gpio_store);
  150. static DEVICE_ATTR(gpio8, S_IWUSR|S_IRUGO,
  151. tle62x0_gpio_show, tle62x0_gpio_store);
  152. static DEVICE_ATTR(gpio9, S_IWUSR|S_IRUGO,
  153. tle62x0_gpio_show, tle62x0_gpio_store);
  154. static DEVICE_ATTR(gpio10, S_IWUSR|S_IRUGO,
  155. tle62x0_gpio_show, tle62x0_gpio_store);
  156. static DEVICE_ATTR(gpio11, S_IWUSR|S_IRUGO,
  157. tle62x0_gpio_show, tle62x0_gpio_store);
  158. static DEVICE_ATTR(gpio12, S_IWUSR|S_IRUGO,
  159. tle62x0_gpio_show, tle62x0_gpio_store);
  160. static DEVICE_ATTR(gpio13, S_IWUSR|S_IRUGO,
  161. tle62x0_gpio_show, tle62x0_gpio_store);
  162. static DEVICE_ATTR(gpio14, S_IWUSR|S_IRUGO,
  163. tle62x0_gpio_show, tle62x0_gpio_store);
  164. static DEVICE_ATTR(gpio15, S_IWUSR|S_IRUGO,
  165. tle62x0_gpio_show, tle62x0_gpio_store);
  166. static DEVICE_ATTR(gpio16, S_IWUSR|S_IRUGO,
  167. tle62x0_gpio_show, tle62x0_gpio_store);
  168. static struct device_attribute *gpio_attrs[] = {
  169. [0] = &dev_attr_gpio1,
  170. [1] = &dev_attr_gpio2,
  171. [2] = &dev_attr_gpio3,
  172. [3] = &dev_attr_gpio4,
  173. [4] = &dev_attr_gpio5,
  174. [5] = &dev_attr_gpio6,
  175. [6] = &dev_attr_gpio7,
  176. [7] = &dev_attr_gpio8,
  177. [8] = &dev_attr_gpio9,
  178. [9] = &dev_attr_gpio10,
  179. [10] = &dev_attr_gpio11,
  180. [11] = &dev_attr_gpio12,
  181. [12] = &dev_attr_gpio13,
  182. [13] = &dev_attr_gpio14,
  183. [14] = &dev_attr_gpio15,
  184. [15] = &dev_attr_gpio16
  185. };
  186. static int to_gpio_num(struct device_attribute *attr)
  187. {
  188. int ptr;
  189. for (ptr = 0; ptr < ARRAY_SIZE(gpio_attrs); ptr++) {
  190. if (gpio_attrs[ptr] == attr)
  191. return ptr;
  192. }
  193. return -1;
  194. }
  195. static int tle62x0_probe(struct spi_device *spi)
  196. {
  197. struct tle62x0_state *st;
  198. struct tle62x0_pdata *pdata;
  199. int ptr;
  200. int ret;
  201. pdata = dev_get_platdata(&spi->dev);
  202. if (pdata == NULL) {
  203. dev_err(&spi->dev, "no device data specified\n");
  204. return -EINVAL;
  205. }
  206. st = kzalloc(sizeof(struct tle62x0_state), GFP_KERNEL);
  207. if (st == NULL)
  208. return -ENOMEM;
  209. st->us = spi;
  210. st->nr_gpio = pdata->gpio_count;
  211. st->gpio_state = pdata->init_state;
  212. mutex_init(&st->lock);
  213. ret = device_create_file(&spi->dev, &dev_attr_status_show);
  214. if (ret) {
  215. dev_err(&spi->dev, "cannot create status attribute\n");
  216. goto err_status;
  217. }
  218. for (ptr = 0; ptr < pdata->gpio_count; ptr++) {
  219. ret = device_create_file(&spi->dev, gpio_attrs[ptr]);
  220. if (ret) {
  221. dev_err(&spi->dev, "cannot create gpio attribute\n");
  222. goto err_gpios;
  223. }
  224. }
  225. /* tle62x0_write(st); */
  226. spi_set_drvdata(spi, st);
  227. return 0;
  228. err_gpios:
  229. while (--ptr >= 0)
  230. device_remove_file(&spi->dev, gpio_attrs[ptr]);
  231. device_remove_file(&spi->dev, &dev_attr_status_show);
  232. err_status:
  233. kfree(st);
  234. return ret;
  235. }
  236. static int tle62x0_remove(struct spi_device *spi)
  237. {
  238. struct tle62x0_state *st = spi_get_drvdata(spi);
  239. int ptr;
  240. for (ptr = 0; ptr < st->nr_gpio; ptr++)
  241. device_remove_file(&spi->dev, gpio_attrs[ptr]);
  242. device_remove_file(&spi->dev, &dev_attr_status_show);
  243. kfree(st);
  244. return 0;
  245. }
  246. static struct spi_driver tle62x0_driver = {
  247. .driver = {
  248. .name = "tle62x0",
  249. },
  250. .probe = tle62x0_probe,
  251. .remove = tle62x0_remove,
  252. };
  253. module_spi_driver(tle62x0_driver);
  254. MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
  255. MODULE_DESCRIPTION("TLE62x0 SPI driver");
  256. MODULE_LICENSE("GPL v2");
  257. MODULE_ALIAS("spi:tle62x0");