Re: [PATCH v6 2/2] mtd: rawnand: Add NAND controller support on Intel LGM SoC

[Andy Shevchenko <andriy.shevchenko@intel.com>]

On Wed, May 13, 2020 at 06:46:15PM +0800, Ramuthevar,Vadivel MuruganX wrote:
> From: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@linux.intel.com>
> 
> This patch adds the new IP of Nand Flash Controller(NFC) support
> on Intel's Lightning Mountain(LGM) SoC.
> 
> DMA is used for burst data transfer operation, also DMA HW supports
> aligned 32bit memory address and aligned data access by default.
> DMA burst of 8 supported. Data register used to support the read/write
> operation from/to device.
> 
> NAND controller driver implements ->exec_op() to replace legacy hooks,
> these specific call-back method to execute NAND operations.

...

> +static int ebu_nand_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct ebu_nand_controller *ebu_host;
> +	struct nand_chip *nand;
> +	struct mtd_info *mtd;
> +	struct resource *res;
> +	char *resname;
> +	int ret, i;
> +	u32 reg;
> +
> +	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 = devm_ioremap_resource(&pdev->dev, res);

devm_platform_ioremap_resource_byname

> +	if (IS_ERR(ebu_host->ebu))
> +		return PTR_ERR(ebu_host->ebu);
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "hsnand");
> +	ebu_host->hsnand = devm_ioremap_resource(&pdev->dev, res);

devm_platform_ioremap_resource_byname

> +	if (IS_ERR(ebu_host->hsnand))
> +		return PTR_ERR(ebu_host->hsnand);
> +
> +	ret = device_property_read_u32(dev, "nand,cs", &reg);
> +	if (ret) {
> +		dev_err(dev, "failed to get chip select: %d\n", ret);
> +		return ret;
> +	}
> +	ebu_host->cs_num = reg;
> +
> +	for (i = 0; i < MAX_CS; i++) {
> +		resname = devm_kasprintf(dev, GFP_KERNEL, "nand_cs%d", i);
> +		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> +						   resname);

if res is NULL?

> +		ebu_host->cs[i].chipaddr = devm_ioremap_resource(dev, res);
> +		ebu_host->cs[i].nand_pa = res->start;
> +			if (IS_ERR(ebu_host->cs[i].chipaddr))
> +				return PTR_ERR(ebu_host->cs[i].chipaddr);

Something happened with ordering / indentation along these lines...

> +	}
> +

> +	for (i = 0; i < MAX_CS; i++) {
> +		resname = devm_kasprintf(dev, GFP_KERNEL, "addr_sel%d", i);
> +		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> +						   resname);

if res is NULL?

> +		ebu_host->cs[i].addr_sel = res->start;
> +		writel(ebu_host->cs[i].addr_sel | EBU_ADDR_MASK(5) |
> +		       EBU_ADDR_SEL_REGEN, ebu_host->ebu + EBU_ADDR_SEL(i));
> +	}

> +	return ret;
> +}

...

> +static int ebu_nand_remove(struct platform_device *pdev)
> +{
> +	struct ebu_nand_controller *ebu_host = platform_get_drvdata(pdev);
> +

> +	if (ebu_host) {

How it can be NULL here?

> +		mtd_device_unregister(nand_to_mtd(&ebu_host->chip));
> +		nand_cleanup(&ebu_host->chip);
> +		ebu_nand_disable(&ebu_host->chip);
> +
> +		if (ebu_host->dma_rx || ebu_host->dma_tx)
> +			ebu_dma_cleanup(ebu_host);
> +
> +		clk_disable_unprepare(ebu_host->clk);
> +	}
> +
> +	return 0;
> +}


-- 
With Best Regards,
Andy Shevchenko