S5PV210(TQ210)学习笔记——Nand flash驱动编写

跟裸机程序一样，S5PV210的Nandflash模块跟S3C2440的Nand flash模块非常相似，如果不引入ECC，驱动程序的编写也非常简单，具体的分析及编写过程强烈推荐观看韦东山老师的视频教程，我是使用的Linux-3.8.6（Linux-3.8.3也一样）内核，驱动的API函数有些变化，不过原理是相通的，稍微看一下内核源码并参考下其他平台的相关代码就可以自己写出Nand flash驱动了，下面是Nand flash驱动的源码，没有启用ECC，当然，你也可以改成软件ECC，但是我的觉得既然软件ECC不如HWECC快，我就采用硬件ECC吧，我会在下篇文章中加入HWECC。

1. #include
2. #include
3. #include
4. #include
5. #include
6. #include
7. #include
8. #include
10. structs5p_nand_regs{
11. unsignedlongnfconf;
12. unsignedlongnfcont;
13. unsignedlongnfcmmd;
14. unsignedlongnfaddr;
15. unsignedlongnfdata;
16. unsignedlongnfmeccd0;
17. unsignedlongnfmeccd1;
18. unsignedlongnfseccd;
19. unsignedlongnfsblk;
20. unsignedlongnfeblk;
21. unsignedlongnfstat;
22. unsignedlongnfeccerr0;
23. unsignedlongnfeccerr1;
24. unsignedlongnfmecc0;
25. unsignedlongnfmecc1;
26. unsignedlongnfsecc;
27. unsignedlongnfmlcbitpt;
28. };
30. structs5p_nand_ecc{
31. unsignedlongnfeccconf;
32. unsignedlongnfecccont;
33. unsignedlongnfeccstat;
34. unsignedlongnfeccsecstat;
35. unsignedlongnfeccprgecc0;
36. unsignedlongnfeccprgecc1;
37. unsignedlongnfeccprgecc2;
38. unsignedlongnfeccprgecc3;
39. unsignedlongnfeccprgecc4;
40. unsignedlongnfeccprgecc5;
41. unsignedlongnfeccprgecc6;
42. unsignedlongnfeccerl0;
43. unsignedlongnfeccerl1;
44. unsignedlongnfeccerl2;
45. unsignedlongnfeccerl3;
46. unsignedlongnfeccerl4;
47. unsignedlongnfeccerl5;
48. unsignedlongnfeccerl6;
49. unsignedlongnfeccerl7;
50. unsignedlongnfeccerp0;
51. unsignedlongnfeccerp1;
52. unsignedlongnfeccerp2;
53. unsignedlongnfeccerp3;
54. unsignedlongnfeccconecc0;
55. unsignedlongnfeccconecc1;
56. unsignedlongnfeccconecc2;
57. unsignedlongnfeccconecc3;
58. unsignedlongnfeccconecc4;
59. unsignedlongnfeccconecc5;
60. unsignedlongnfeccconecc6;
61. };
63. staticstructnand_chip*nand_chip;
64. staticstructmtd_info*s5p_mtd_info;
65. staticstructs5p_nand_regs*s5p_nand_regs;
66. staticstructs5p_nand_ecc*s5p_nand_ecc;
67. staticstructclk*s5p_nand_clk;
69. staticstructmtd_partitions5p_nand_partions[]={
70. [0]={
71. .name="bootloader",
72. .offset=0,
73. .size=SZ_1M,
74. },
76. [1]={
77. .name="kernel",
78. .offset=MTDPART_OFS_APPEND,
79. .size=5*SZ_1M,
80. },
82. [2]={
83. .name="rootfs",
84. .offset=MTDPART_OFS_APPEND,
85. .size=MTDPART_SIZ_FULL,
86. },
87. };
89. staticvoids5p_nand_select_chip(structmtd_info*mtd,intchipnr){
90. if(chipnr==-1){
91. s5p_nand_regs->nfcont|=(1<<1);
92. }
93. else{
94. s5p_nand_regs->nfcont&=~(1<<1);
95. }
96. }
98. staticvoids5p_nand_cmd_ctrl(structmtd_info*mtd,intcmd,unsignedintctrl)
99. {
100. if(ctrl&NAND_CLE){
101. s5p_nand_regs->nfcmmd=cmd;
102. }
103. else{
104. s5p_nand_regs->nfaddr=cmd;
105. }
106. }
108. staticints5p_nand_ready(structmtd_info*mtd){
109. return(s5p_nand_regs->nfstat&0x1);
110. }
112. staticints5p_nand_probe(structplatform_device*pdev){
113. intret=0;
114. structresource*mem;
115. //硬件部分初始化
116. mem=platform_get_resource(pdev,IORESOURCE_MEM,0);
117. if(!mem){
118. dev_err(&pdev->dev,"cantgetI/Oresourcemem");
119. return-ENXIO;
120. }
122. s5p_nand_regs=(structs5p_nand_regs*)ioremap(mem->start,resource_size(mem));
123. if(s5p_nand_regs==NULL){
124. dev_err(&pdev->dev,"ioremapfailed");
125. ret=-EIO;
126. gotoerr_exit;
127. }
129. s5p_nand_ecc=(structs5p_nand_ecc*)ioremap(0xB0E20000,sizeof(structs5p_nand_ecc));
130. if(s5p_nand_ecc==NULL){
131. dev_err(&pdev->dev,"ioremapfailed");
132. ret=-EIO;
133. gotoerr_iounmap;
134. }
136. s5p_nand_clk=clk_get(&pdev->dev,"nand");
137. if(s5p_nand_clk==NULL){
138. dev_dbg(&pdev->dev,"getclkfailed");
139. ret=-ENODEV;
140. gotoerr_iounmap;
141. }
143. clk_enable(s5p_nand_clk);
145. s5p_nand_regs->nfconf=(3<<12)|(5<<8)|(3<<4)|(1<<1);
146. s5p_nand_regs->nfcont|=3;
148. //分配驱动相关结构体
149. nand_chip=(structnand_chip*)kzalloc(sizeof(structnand_chip),GFP_KERNEL);
150. if(nand_chip==NULL){
151. dev_err(&pdev->dev,"failedtoallocatenand_chipstructure");
152. ret=-ENOMEM;
153. gotoerr_clk_put;
154. }
156. s5p_mtd_info=(structmtd_info*)kzalloc(sizeof(structmtd_info),GFP_KERNEL);
157. if(s5p_mtd_info==NULL){
158. dev_err(&pdev->dev,"failedtoallocatemtd_infostructure");
159. ret=-ENOMEM;
160. gotoerr_free_chip;
161. }
163. //设置驱动相关结构体
164. nand_chip->select_chip=s5p_nand_select_chip;
165. nand_chip->cmd_ctrl=s5p_nand_cmd_ctrl;
166. nand_chip->IO_ADDR_R=&s5p_nand_regs->nfdata;
167. nand_chip->IO_ADDR_W=&s5p_nand_regs->nfdata;
168. nand_chip->dev_ready=s5p_nand_ready;
169. nand_chip->ecc.mode=NAND_ECC_SOFT;
171. s5p_mtd_info->priv=nand_chip;
172. s5p_mtd_info->owner=THIS_MODULE;
174. //扫描Nandflash设备
175. if(nand_scan(s5p_mtd_info,1)){
176. dev_dbg(&pdev->dev,"nandscanerror");
177. gotoerr_free_info;
178. }
180. //添加分区信息
181. ret=mtd_device_parse_register(s5p_mtd_info,NULL,NULL,s5p_nand_partions,ARRAY_SIZE(s5p_nand_partions));
182. if(!ret)
183. return0;
185. err_free_info:
186. kfree(s5p_mtd_info);
187. err_free_chip:
188. kfree(nand_chip);
189. err_clk_put:
190. clk_disable(s5p_nand_clk);
191. clk_put(s5p_nand_clk);
192. err_iounmap:
193. //if(s5p_nand_ecc==NULL)
194. //iounmap(s5p_nand_ecc);
195. if(s5p_nand_regs==NULL)
196. iounmap(s5p_nand_regs);
197. err_exit:
198. returnret;
199. }
201. staticints5p_nand_remove(structplatform_device*pdev){
202. nand_release(s5p_mtd_info);
203. kfree(s5p_mtd_info);
204. kfree(nand_chip);
206. clk_disable(s5p_nand_clk);
207. clk_put(s5p_nand_clk);
209. if(s5p_nand_regs==NULL)
210. iounmap(s5p_nand_regs);
211. return0;
212. }
214. staticstructplatform_drivers5p_nand_drv={
215. .driver={
216. .owner=THIS_MODULE,
217. .name="s5p-nand",
218. },
219. .probe=s5p_nand_probe,
220. .remove=s5p_nand_remove,
221. };
223. module_platform_driver(s5p_nand_drv);
224. MODULE_LICENSE("GPL");

源码都在上面，具体的原理还是参考视频或者其他资料，这里就不多说了，如果有任何问题，欢迎留言讨论。

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