Re: [PATCH v3 2/2] mtd: rawnand: Add NAND controller support on Intel LGM SoC

From: Miquel Raynal
Date: Mon Apr 27 2020 - 11:51:37 EST


Hi Ramuthevar,

> > +static int ebu_nand_probe(struct platform_device *pdev)
> > +{
> > + struct device *dev = &pdev->dev;
> > + struct ebu_nand_controller *ebu_host;
> > + struct nand_chip *nand;
> > + phys_addr_t nandaddr_pa;
> > + struct mtd_info *mtd;
> > + struct resource *res;
> > + int ret;
> > + u32 cs;
> > +
> > + ebu_host = devm_kzalloc(dev, sizeof(*ebu_host), GFP_KERNEL);
> > + if (!ebu_host)
> > + return -ENOMEM;
> > +
> > + ebu_host->dev = dev;
> > + nand_controller_init(&ebu_host->controller);
> > +
> > + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ebunand");
> > + ebu_host->ebu_addr = devm_ioremap_resource(&pdev->dev, res);
> > + if (IS_ERR(ebu_host->ebu_addr))
> > + return PTR_ERR(ebu_host->ebu_addr);
> > +
> > + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "hsnand");
> > + ebu_host->nand_addr = devm_ioremap_resource(&pdev->dev, res);
> > + if (IS_ERR(ebu_host->nand_addr))
> > + return PTR_ERR(ebu_host->nand_addr);
> > +
> > + ret = device_property_read_u32(dev, "nand,cs", &cs);
>
> CS ids should be encoded in the reg property (see [1]).

Is it your choice to only support a single CS or is it actually a
controller limitation? If the latter, it would be much better I think
to anticipate the addition of the support for another CS. And in
this case there are many places in this driver that should be
more generic.

> > + if (ret) {
> > + dev_err(dev, "failed to get chip select: %d\n", ret);
> > + return ret;
> > + }
> > +
> > + ebu_host->cs = cs;
> > + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "nand_cs0");

Thanks,
MiquÃl