S5PV210之Nand flash驱动编写

　　大家好，又到了天嵌【嵌入式分享】的时间，相对于前几期【嵌入式分享】做的主要是TQ335X开发板的技术分享，本期决定做同是cortex-a8系列的TQ210开发板的技术分享。本期是关于TQ210开发板的Nand flash驱动编写，可能源码部分会比较多，本文由博主girlkoo编写，感谢他的分享。　　跟裸机程序一样，S5PV210(TQ210)的Nand flash模块跟S3C2440(TQ2440)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，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。
[*]#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[] = {  
[*]    = {  
[*]        .name   = "bootloader",  
[*]        .offset = 0,  
[*]        .size   = SZ_1M,  
[*]    },  
[*]  
[*]    = {  
[*]        .name   = "kernel",  
[*]        .offset = MTDPART_OFS_APPEND,  
[*]        .size   = 5*SZ_1M,  
[*]    },  
[*]  
[*]    = {  
[*]        .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 |= (1<<1);  
[*]    }  
[*]    else{  
[*]        s5p_nand_regs->nfcont &= ~(1<<1);  
[*]    }  
[*]}  
[*]  
[*]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 mem\n");  
[*]        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 failed\n");  
[*]        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 failed\n");  
[*]        ret = -EIO;  
[*]        goto err_iounmap;  
[*]    }  
[*]      
[*]    s5p_nand_clk = clk_get(&pdev->dev, "nand");  
[*]    if(s5p_nand_clk == NULL){  
[*]        dev_dbg(&pdev->dev, "get clk failed\n");  
[*]        ret = -ENODEV;  
[*]        goto err_iounmap;  
[*]    }  
[*]  
[*]    clk_enable(s5p_nand_clk);  
[*]      
[*]    s5p_nand_regs->nfconf = (3<<12)|(5<<8)|(3<<4)|(1<<1);  
[*]    s5p_nand_regs->nfcont |= 3;  
[*]  
[*]    //分配驱动相关结构体  
[*]    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 structure\n");  
[*]        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 structure\n");  
[*]        ret = -ENOMEM;  
[*]        goto err_free_chip;  
[*]    }  
[*]  
[*]    //设置驱动相关结构体  
[*]    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;  
[*]  
[*]    //扫描Nand flash 设备  
[*]    if(nand_scan(s5p_mtd_info, 1)){  
[*]        dev_dbg(&pdev->dev, "nand scan error\n");  
[*]        goto err_free_info;  
[*]    }  
[*]  
[*]    //添加分区信息  
[*]    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");  
　　上述源码为嵌入式爱好者分享，如有更新，请咨询相关客服与销售人员，以便更新与开发。　　操作所使用的硬件：　　TQ210V6开发板