dm9000a驱动源码分析

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dm9000a框架原理图:

EEPROM Interface接口用于存放mac地址，InternalSRAM用于存放收发数据，MII部分把MAC部分与PHY部分连接起来通信，AUTO-MDIX用于自适应10/100M网络,在物理层上,MAC在PHY之下。 

 

由dm9000a驱动可知，dm9000a驱动是用platform模型编写的，分析一个驱动源码都是从模块加载函数module_init()开始，而dm9000a加载函数是module_init(dm9000_init).

 

继而调用：

1. static int __init

2. dm9000_init(void)

3. {

4. printk(KERN_INFO "%s Ethernet Driver, V%s\n", CARDNAME, DRV_VERSION);

5. return platform_driver_register(&dm9000_driver);

6. }

 

dm9000_driver结构体：

1. static struct platform_driver dm9000_driver = {

2. .driver = {

3. .name = "dm9000",//名字

4. .owner = THIS_MODULE,

5. },

6. .probe = dm9000_probe,//模块加载后，调用probe函数

7. .remove = __devexit_p(dm9000_drv_remove),

8. .suspend = dm9000_drv_suspend,

9. .resume = dm9000_drv_resume,

10. };

模块加载之后，调用probe函数，如下：

 

1. /*

2. * Search DM9000 board, allocate space and register it

3. */

4. static int __devinit

5. dm9000_probe(struct platform_device *pdev)

6. {

7. struct dm9000_plat_data *pdata = pdev->dev.platform_data;

8. struct board_info *db; /* Point a board information structure */

9. struct net_device *ndev;

10. const unsigned char *mac_src;

11. int ret = 0;

12. int iosize;

13. int i;

14. u32 id_val;

15.  

16. unsigned char ne_def_eth_mac_addr[]={0x00,0x12,0x34,0x56,0x80,0x49};

17.  

18. /* ------------------------------------------------------------------------ */

19. static void *bwscon;

20. static void *gpfcon;

21. static void *extint0;

22. static void *intmsk;

23. #define BWSCON (0x48000000)

24. #define GPFCON (0x56000050)

25. #define EXTINT0 (0x56000088)

26. #define INTMSK (0x4A000008)

27.  

28. bwscon=ioremap_nocache(BWSCON,0x0000004);

29. gpfcon=ioremap_nocache(GPFCON,0x0000004);

30. extint0=ioremap_nocache(EXTINT0,0x0000004);

31. intmsk=ioremap_nocache(INTMSK,0x0000004);

32.  

33. writel(readl(bwscon)|0xc0000,bwscon);

34. writel( (readl(gpfcon) & ~(0x3 << 14)) | (0x2 << 14), gpfcon);

35. writel( readl(gpfcon) | (0x1 << 7), gpfcon); // Disable pull-up

36. writel( (readl(extint0) & ~(0xf << 28)) | (0x4 << 28), extint0); //rising edge

37. writel( (readl(intmsk)) & ~0x80, intmsk);

38. /* ------------------------------------------------------------------------ */

39.  

40. /* Init network device */

41. /* 分配eth网卡资源，私有数据区保存board_info*/

42. ndev = alloc_etherdev(sizeof(struct board_info));

43. if (!ndev) {

44. dev_err(&pdev->dev, "could not allocate device.\n");

45. return -ENOMEM;

46. }

47.  

48. SET_NETDEV_DEV(ndev, &pdev->dev);

49.  

50. dev_dbg(&pdev->dev, "dm9000_probe()\n");

51.  

52. /* setup board info structure 初始化为0*/

53. db = ndev->priv;

54. memset(db, 0, sizeof(*db));

55.  

56. db->dev = &pdev->dev;

57. db->ndev = ndev;

58. /*初始化spinlock*/

59. spin_lock_init(&db->lock);

60. mutex_init(&db->addr_lock);

61. /*提交一个任务给一个工作队列，你需要填充一个work_struct结构db->phy_poll*/

62. INIT_DELAYED_WORK(&db->phy_poll, dm9000_poll_work);

63. /*获取IO内存和中断资源*/

64. db->addr_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

65. db->data_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);

66. db->irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);

67.  

68. if (db->addr_res == NULL || db->data_res == NULL ||

69. db->irq_res == NULL) {

70. dev_err(db->dev, "insufficient resources\n");

71. ret = -ENOENT;

72. goto out;

73. }

74. /*映射到内核，并获得IO内存的虚拟地址，ioremap完成页表的建立，

75. 不同于vmalloc，但是，它实际上不分配内存*/

76. iosize = res_size(db->addr_res);

77. db->addr_req = request_mem_region(db->addr_res->start, iosize,

78. pdev->name);

79.  

80. if (db->addr_req == NULL) {

81. dev_err(db->dev, "cannot claim address reg area\n");

82. ret = -EIO;

83. goto out;

84. }

85.  

86. db->io_addr = ioremap(db->addr_res->start, iosize);

87.  

88. if (db->io_addr == NULL) {

89. dev_err(db->dev, "failed to ioremap address reg\n");

90. ret = -EINVAL;

91. goto out;

92. }

93.  

94. iosize = res_size(db->data_res);

95. db->data_req = request_mem_region(db->data_res->start, iosize,

96. pdev->name);

97.  

98. if (db->data_req == NULL) {

99. dev_err(db->dev, "cannot claim data reg area\n");

100. ret = -EIO;

101. goto out;

102. }

103.  

104. db->io_data = ioremap(db->data_res->start, iosize);

105.  

106. if (db->io_data == NULL) {

107. dev_err(db->dev, "failed to ioremap data reg\n");

108. ret = -EINVAL;

109. goto out;

110. }

111.  

112. /* fill in parameters for net-dev structure */

113. /*获得网络设备的基地址*/

114. ndev->base_addr = (unsigned long)db->io_addr;

115. /*获得网络设备的中断号*/

116. ndev->irq = db->irq_res->start;

117.  

118. /* ensure at least we have a default set of IO routines */

119. /*设置默认的IO函数*/

120. dm9000_set_io(db, iosize);

121.  

122. /*如果平台数据不为空 */

123. if (pdata != NULL) {

124. /* check to see if the driver wants to over-ride the

125. * default IO width */

126.  

127. if (pdata->flags & DM9000_PLATF_8BITONLY)

128. dm9000_set_io(db, 1);

129.  

130. if (pdata->flags & DM9000_PLATF_16BITONLY)

131. dm9000_set_io(db, 2);

132.  

133. if (pdata->flags & DM9000_PLATF_32BITONLY)

134. dm9000_set_io(db, 4);

135.  

136. /* check to see if there are any IO routine

137. * over-rides */

138.  

139. if (pdata->inblk != NULL)

140. db->inblk = pdata->inblk;

141.  

142. if (pdata->outblk != NULL)

143. db->outblk = pdata->outblk;

144.  

145. if (pdata->dumpblk != NULL)

146. db->dumpblk = pdata->dumpblk;

147.  

148. db->flags = pdata->flags;

149. }

150.  

151. #ifdef CONFIG_DM9000_FORCE_SIMPLE_PHY_POLL

152. db->flags |= DM9000_PLATF_SIMPLE_PHY;

153. #endif

154. /*根据board info信息，复位DM9000芯片*/

155. dm9000_reset(db);

156. /*读取Vendor ID Register,Product ID Register中的值，与0x90000A46比较，如果相等，则说明是DM9000*/

157. /* try multiple times, DM9000 sometimes gets the read wrong */

158. for (i = 0; i < 8; i++) {

159. id_val = ior(db, DM9000_VIDL);

160. id_val |= (u32)ior(db, DM9000_VIDH) << 8;

161. id_val |= (u32)ior(db, DM9000_PIDL) << 16;

162. id_val |= (u32)ior(db, DM9000_PIDH) << 24;

163.  

164. if (id_val == DM9000_ID)

165. break;

166. dev_err(db->dev, "read wrong id 0x%08x\n", id_val);

167. }

168. /*芯片的ID获取失败，驱动不匹配*/

169. if (id_val != DM9000_ID) {

170. dev_err(db->dev, "wrong id: 0x%08x\n", id_val);

171. ret = -ENODEV;

172. goto out;

173. }

174.  

175. /* Identify what type of DM9000 we are working on */

176. /*读取Chip Revision Register中的值*/

177. id_val = ior(db, DM9000_CHIPR);

178. dev_dbg(db->dev, "dm9000 revision 0x%02x\n", id_val);

179.  

180. switch (id_val) {

181. case CHIPR_DM9000A:

182. db->type = TYPE_DM9000A;

183. break;

184. case CHIPR_DM9000B:

185. db->type = TYPE_DM9000B;

186. break;

187. default:

188. dev_dbg(db->dev, "ID %02x => defaulting to DM9000E\n", id_val);

189. db->type = TYPE_DM9000E;

190. }

191.  

192. /* from this point we assume that we have found a DM9000 */

193.  

194. /* driver system function */

195. /*设置部分net_device字段*/

196. ether_setup(ndev);

197.  

198. ndev->open = &dm9000_open;

199. ndev->hard_start_xmit = &dm9000_start_xmit;

200. ndev->tx_timeout = &dm9000_timeout;

201. ndev->watchdog_timeo = msecs_to_jiffies(watchdog);

202. ndev->stop = &dm9000_stop;

203. ndev->set_multicast_list = &dm9000_hash_table;

204. /*对ethtool支持的相关声明可在<linux/ethtool.h>中找到。

205. 它的核心是一个ethtool_ops类型的结构，里边包含一个全部

206. 的24个不同的方法来支持ethtool*/

207. ndev->ethtool_ops = &dm9000_ethtool_ops;

208. ndev->do_ioctl = &dm9000_ioctl;

209.  

210. #ifdef CONFIG_NET_POLL_CONTROLLER

211. ndev->poll_controller = &dm9000_poll_controller;

212. #endif

213.  

214. db->msg_enable = NETIF_MSG_LINK;

215. db->mii.phy_id_mask = 0x1f;

216. db->mii.reg_num_mask = 0x1f;

217. db->mii.force_media = 0;

218. db->mii.full_duplex = 0;

219. db->mii.dev = ndev;

220. db->mii.mdio_read = dm9000_phy_read;

221. db->mii.mdio_write = dm9000_phy_write;

222. /*MAC地址的源是eeprom*/

223. mac_src = "eeprom";

224.  

225. /* try reading the node address from the attached EEPROM */

226. for (i = 0; i < 6; i += 2)

227. dm9000_read_eeprom(db, i / 2, ndev->dev_addr+i);

228. /*如果从eeprom中读取的地址无效，并且私有数据不为空，从platform_device的私有数据中获取dev_addr*/

229. if (!is_valid_ether_addr(ndev->dev_addr) && pdata != NULL) {

230. mac_src = "platform data";

231. memcpy(ndev->dev_addr, pdata->dev_addr, 6);

232. }

233. /*如果地址依然无效，从PAR:物理地址(MAC)寄存器(Physical Address Register)中读取*/

234. if (!is_valid_ether_addr(ndev->dev_addr)) {

235. /* try reading from mac */

236.  

237. mac_src = "chip";

238. for (i = 0; i < 6; i++)

239. //ndev->dev_addr[i] = ior(db, i+DM9000_PAR); // by bai

240. ndev->dev_addr[i] = ne_def_eth_mac_addr[i];

241. }

242. /*查看以太网网卡设备地址是否有效*/

243. if (!is_valid_ether_addr(ndev->dev_addr))

244. dev_warn(db->dev, "%s: Invalid ethernet MAC address. Please "

245. "set using ifconfig\n", ndev->name);

246. /*将ndev保存到pdev->dev->driver_data中*/

247. platform_set_drvdata(pdev, ndev);

248. /*一切都初始化好后，注册网络设备*/

249. ret = register_netdev(ndev);

250.  

251. if (ret == 0) {

252. DECLARE_MAC_BUF(mac);

253. printk(KERN_INFO "%s: dm9000%c at %p,%p IRQ %d MAC: %s (%s)\n",

254. ndev->name, dm9000_type_to_char(db->type),

255. db->io_addr, db->io_data, ndev->irq,

256. print_mac(mac, ndev->dev_addr), mac_src);

257. }

258. return 0;

259.  

260. out:

261. dev_err(db->dev, "not found (%d).\n", ret);

262. /*失败时,释放资源*/

263. dm9000_release_board(pdev, db);

264. free_netdev(ndev);

265.  

266. return ret;

267. }

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