大家好，又到了天嵌【嵌入式分享】的時(shí)間，相對(duì)于前幾期【嵌入式分享】做的主要是TQ335X開發(fā)板的技術(shù)分享，本期決定做同是cortex-a8系列的TQ210開發(fā)板的技術(shù)分享。本期是關(guān)于TQ210開發(fā)板的Nand flash驅(qū)動(dòng)編寫，可能源碼部分會(huì)比較多，本文由博主girlkoo編寫，感謝他的分享。

跟裸機(jī)程序一樣，S5PV210(TQ210)的Nand flash模塊跟S3C2440(TQ2440)的Nand flash模塊非常相似，如果不引入ECC，驅(qū)動(dòng)程序的編寫也非常簡(jiǎn)單，我是使用的Linux-3.8.6(Linux-3.8.3也一樣)內(nèi)核，驅(qū)動(dòng)的API函數(shù)有些變化，不過原理是相通的，稍微看一下內(nèi)核源碼并參考下其他平臺(tái)的相關(guān)代碼就可以自己寫出Nand flash驅(qū)動(dòng)了，下面是Nand flash驅(qū)動(dòng)的源碼，沒有啟用ECC，當(dāng)然，你也可以改成軟件ECC，但是我的覺得既然軟件ECC不如HWECC快，我就采用硬件ECC吧。

#include

#include

#include

#include

#include

#include

#include

#include

struct s5p_nand_regs{

unsigned long nfconf;

unsigned long nfcont;

unsigned long nfcmmd;

unsigned long nfaddr;

unsigned long nfdata;

unsigned long nfmeccd0;

unsigned long nfmeccd1;

unsigned long nfseccd;

unsigned long nfsblk;

unsigned long nfeblk;

unsigned long nfstat;

unsigned long nfeccerr0;

unsigned long nfeccerr1;

unsigned long nfmecc0;

unsigned long nfmecc1;

unsigned long nfsecc;

unsigned long nfmlcbitpt;

};

struct s5p_nand_ecc{

unsigned long nfeccconf;

unsigned long nfecccont;

unsigned long nfeccstat;

unsigned long nfeccsecstat;

unsigned long nfeccprgecc0;

unsigned long nfeccprgecc1;

unsigned long nfeccprgecc2;

unsigned long nfeccprgecc3;

unsigned long nfeccprgecc4;

unsigned long nfeccprgecc5;

unsigned long nfeccprgecc6;

unsigned long nfeccerl0;

unsigned long nfeccerl1;

unsigned long nfeccerl2;

unsigned long nfeccerl3;

unsigned long nfeccerl4;

unsigned long nfeccerl5;

unsigned long nfeccerl6;

unsigned long nfeccerl7;

unsigned long nfeccerp0;

unsigned long nfeccerp1;

unsigned long nfeccerp2;

unsigned long nfeccerp3;

unsigned long nfeccconecc0;

unsigned long nfeccconecc1;

unsigned long nfeccconecc2;

unsigned long nfeccconecc3;

unsigned long nfeccconecc4;

unsigned long nfeccconecc5;

unsigned long nfeccconecc6;

};

static struct nand_chip *nand_chip;

static struct mtd_info *s5p_mtd_info;

static struct s5p_nand_regs *s5p_nand_regs;

static struct s5p_nand_ecc *s5p_nand_ecc;

static struct clk *s5p_nand_clk;

static struct mtd_partition s5p_nand_partions[] = {

[0] = {

.name = bootloader,

.offset = 0,

.size = SZ_1M,

},

[1] = {

.name = kernel,

.offset = MTDPART_OFS_APPEND,

.size = 5*SZ_1M,

},

[2] = {

.name = rootfs,

.offset = MTDPART_OFS_APPEND,

.size = MTDPART_SIZ_FULL,

},

};

static void s5p_nand_select_chip(struct mtd_info *mtd, int chipnr){

if(chipnr == -1){

s5p_nand_regs->nfcont |= (11);

}

else{

s5p_nand_regs->nfcont = ~(11);

}

}

static void s5p_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)

{

if (ctrl NAND_CLE){

s5p_nand_regs->nfcmmd = cmd;

}

else{

s5p_nand_regs->nfaddr = cmd;

}

}

static int s5p_nand_ready(struct mtd_info *mtd){

return (s5p_nand_regs->nfstat 0x1);

}

static int s5p_nand_probe(struct platform_device *pdev){

int ret = 0;

struct resource *mem;

//硬件部分初始化

mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);

if (!mem) {

dev_err(pdev->dev, can't get I/O resource memn);

return -ENXIO;

}

s5p_nand_regs = (struct s5p_nand_regs *)ioremap(mem->start, resource_size(mem));

if (s5p_nand_regs == NULL) {

dev_err(pdev->dev, ioremap failedn);

ret = -EIO;

goto err_exit;

}

s5p_nand_ecc = (struct s5p_nand_ecc *)ioremap(0xB0E20000, sizeof(struct s5p_nand_ecc));

if(s5p_nand_ecc == NULL){

dev_err(pdev->dev, ioremap failedn);

ret = -EIO;

goto err_iounmap;

}

s5p_nand_clk = clk_get(pdev->dev, nand);

if(s5p_nand_clk == NULL){

dev_dbg(pdev->dev, get clk failedn);

ret = -ENODEV;

goto err_iounmap;

}

clk_enable(s5p_nand_clk);

s5p_nand_regs->nfconf = (312)|(58)|(34)|(11);

s5p_nand_regs->nfcont |= 3;

//分配驅(qū)動(dòng)相關(guān)結(jié)構(gòu)體

nand_chip = (struct nand_chip *)kzalloc(sizeof(struct nand_chip), GFP_KERNEL);

if(nand_chip == NULL){

dev_err(pdev->dev, failed to allocate nand_chip structuren);

ret = -ENOMEM;

goto err_clk_put;

}

s5p_mtd_info = (struct mtd_info *)kzalloc(sizeof(struct mtd_info), GFP_KERNEL);

if(s5p_mtd_info == NULL){

dev_err(pdev->dev, failed to allocate mtd_info structuren);

ret = -ENOMEM;

goto err_free_chip;

}

//設(shè)置驅(qū)動(dòng)相關(guān)結(jié)構(gòu)體

nand_chip->select_chip = s5p_nand_select_chip;

nand_chip->cmd_ctrl = s5p_nand_cmd_ctrl;

nand_chip->IO_ADDR_R = s5p_nand_regs->nfdata;

nand_chip->IO_ADDR_W = s5p_nand_regs->nfdata;

nand_chip->dev_ready = s5p_nand_ready;

nand_chip->ecc.mode = NAND_ECC_SOFT;

s5p_mtd_info->priv = nand_chip;

s5p_mtd_info->owner = THIS_MODULE;

//掃描Nand flash 設(shè)備

if(nand_scan(s5p_mtd_info, 1)){

dev_dbg(pdev->dev, nand scan errorn);

goto err_free_info;

}

//添加分區(qū)信息

ret = mtd_device_parse_register(s5p_mtd_info, NULL, NULL, s5p_nand_partions, ARRAY_SIZE(s5p_nand_partions));

if(!ret)

return 0;

err_free_info:

kfree(s5p_mtd_info);

err_free_chip:

kfree(nand_chip);

err_clk_put:

clk_disable(s5p_nand_clk);

clk_put(s5p_nand_clk);

err_iounmap:

//if(s5p_nand_ecc == NULL)

// iounmap(s5p_nand_ecc);

if(s5p_nand_regs == NULL)

iounmap(s5p_nand_regs);

err_exit:

return ret;

}

static int s5p_nand_remove(struct platform_device *pdev){

nand_release(s5p_mtd_info);

kfree(s5p_mtd_info);

kfree(nand_chip);

clk_disable(s5p_nand_clk);

clk_put(s5p_nand_clk);

if(s5p_nand_regs == NULL)

iounmap(s5p_nand_regs);

return 0;

}

static struct platform_driver s5p_nand_drv = {

.driver = {

.owner = THIS_MODULE,

.name = s5p-nand,

},

.probe = s5p_nand_probe,

.remove = s5p_nand_remove,

};

module_platform_driver(s5p_nand_drv);

MODULE_LICENSE(GPL);

上述源碼為嵌入式愛好者分享，如有更新，請(qǐng)咨詢相關(guān)客服與銷售人員，以便更新與開發(fā)。

操作所使用的硬件：

TQ210V6開發(fā)板