[U-Boot] [PATCH 5/7] S3C24XX: Add NAND Flash driver

Marek Vasut marex at denx.de
Thu Sep 13 01:45:07 CEST 2012


Dear José Miguel Gonçalves,

> Hi Marek,
> 
> On 09/12/2012 10:11 PM, Marek Vasut wrote:
> > Dear José Miguel Gonçalves,
> > 
> >> +
> >> +/*
> >> + * Hardware specific access to control-lines function
> >> + */
> >> +static void s3c_nand_hwcontrol(struct mtd_info *mtd, int cmd, unsigned
> >> int ctrl) +{
> >> +	s3c24xx_nand *const nand = s3c24xx_get_base_nand();
> >> +	struct nand_chip *this = mtd->priv;
> >> +
> >> +	if (ctrl & NAND_CTRL_CHANGE) {
> >> +		if (ctrl & NAND_CLE)
> >> +			this->IO_ADDR_W = (void __iomem *)&nand->nfcmmd;
> >> +		else if (ctrl & NAND_ALE)
> >> +			this->IO_ADDR_W = (void __iomem *)&nand->nfaddr;
> >> +		else
> >> +			this->IO_ADDR_W = (void __iomem *)&nand->nfdata;
> > 
> > Do you need this cast ?
> 
> Without it gcc gives me a warning:
> 
> s3c24xx_nand.c:90:20: warning: assignment discards `volatile' qualifier
> from pointer target type [enabled by default]

Not that you need to do the assignment into the structure .... use local 
variable, no ?

> > +/*
> > + * Board-specific NAND initialization.
> > + */
> > +int board_nand_init(struct nand_chip *nand)
> > +{
> > +	static int chip_n = 0;
> > +	s3c24xx_nand *const nand_reg = s3c24xx_get_base_nand();
> > +	u_long nfconf, nfcont;
> > +
> > +	if (chip_n == 0) {
> > +		/* Extend NAND timings to the maximum */
> > +		nfconf = readl(&nand_reg->nfconf);
> > +		nfconf |= 0x7770;
> > Magic
> > 
> >> +		writel(nfconf, &nand_reg->nfconf);
> >> +
> >> +		/* Disable chip selects and soft lock, enable controller */
> >> +		nfcont = readl(&nand_reg->nfcont);
> >> +		nfcont &= ~NFCONT_WP;
> >> +		nfcont |= NFCONT_NCE1 | NFCONT_NCE0 | NFCONT_ENABLE;
> >> +		writel(nfcont, &nand_reg->nfcont);
> > 
> > use clrsetbits_le32()
> 
> I will do that and also define some macros for the magic values.
> 
> Regards,
> José Gonçalves

Best regards,
Marek Vasut


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