linux-kernel - Re: [PATCH v3 2/2] mtd: spi-nor: cadence-quadspi: Add support for Octal SPI controller

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Message-ID: <6e6f7c3a-4772-1a17-0f5f-547ea9809283@microchip.com>
Date:   Sun, 20 Jan 2019 14:56:42 +0000
From:   <Tudor.Ambarus@...rochip.com>
To:     <vigneshr@...com>, <bbrezillon@...nel.org>
CC:     <marek.vasut@...il.com>, <robh+dt@...nel.org>,
        <linux-mtd@...ts.infradead.org>, <devicetree@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v3 2/2] mtd: spi-nor: cadence-quadspi: Add support for
 Octal SPI controller

Hi, Vignesh,

On 01/16/2019 12:30 PM, Vignesh R wrote:
> Cadence OSPI controller IP supports Octal IO (x8 IO lines),
> It also has an integrated PHY. IP register layout is very
> similar to existing QSPI IP except for additional bits to support Octal
> and Octal DDR mode. Therefore, extend current driver to support Octal
> mode.
> 
> Signed-off-by: Vignesh R <vigneshr@...com>
> ---
> v3: No changes
> 
> v2:
> Declare Octal mode capability based on compatible.
> 
>  drivers/mtd/spi-nor/cadence-quadspi.c | 54 +++++++++++++++++++++------
>  1 file changed, 42 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c
> index 04cedd3a2bf6..31ed50f78972 100644
> --- a/drivers/mtd/spi-nor/cadence-quadspi.c
> +++ b/drivers/mtd/spi-nor/cadence-quadspi.c
> @@ -93,6 +93,11 @@ struct cqspi_st {
>  	struct cqspi_flash_pdata f_pdata[CQSPI_MAX_CHIPSELECT];
>  };
>  
> +struct cqspi_driver_platdata {
> +	u32 hwcaps_mask;
> +	u8 quirks;
> +};
> +
>  /* Operation timeout value */
>  #define CQSPI_TIMEOUT_MS			500
>  #define CQSPI_READ_TIMEOUT_MS			10
> @@ -101,6 +106,7 @@ struct cqspi_st {
>  #define CQSPI_INST_TYPE_SINGLE			0
>  #define CQSPI_INST_TYPE_DUAL			1
>  #define CQSPI_INST_TYPE_QUAD			2
> +#define CQSPI_INST_TYPE_OCTAL			3
>  
>  #define CQSPI_DUMMY_CLKS_PER_BYTE		8
>  #define CQSPI_DUMMY_BYTES_MAX			4
> @@ -911,6 +917,9 @@ static int cqspi_set_protocol(struct spi_nor *nor, const int read)
>  		case SNOR_PROTO_1_1_4:
>  			f_pdata->data_width = CQSPI_INST_TYPE_QUAD;
>  			break;
> +		case SNOR_PROTO_1_1_8:
> +			f_pdata->data_width = CQSPI_INST_TYPE_OCTAL;
> +			break;
>  		default:
>  			return -EINVAL;
>  		}
> @@ -1213,21 +1222,19 @@ static void cqspi_request_mmap_dma(struct cqspi_st *cqspi)
>  
>  static int cqspi_setup_flash(struct cqspi_st *cqspi, struct device_node *np)
>  {
> -	const struct spi_nor_hwcaps hwcaps = {
> -		.mask = SNOR_HWCAPS_READ |
> -			SNOR_HWCAPS_READ_FAST |
> -			SNOR_HWCAPS_READ_1_1_2 |
> -			SNOR_HWCAPS_READ_1_1_4 |
> -			SNOR_HWCAPS_PP,
> -	};
>  	struct platform_device *pdev = cqspi->pdev;
>  	struct device *dev = &pdev->dev;
> +	struct cqspi_driver_platdata *ddata;

const struct cqspi_driver_platdata *ddata;

> +	struct spi_nor_hwcaps hwcaps;
>  	struct cqspi_flash_pdata *f_pdata;
>  	struct spi_nor *nor;
>  	struct mtd_info *mtd;
>  	unsigned int cs;
>  	int i, ret;
>  
> +	ddata = (struct cqspi_driver_platdata *)of_device_get_match_data(dev);

You forgot to check for NULL. Also, I would expect an implicit type cast, you
can drop the explicit cast.

> +	hwcaps.mask = ddata->hwcaps_mask;
> +
>  	/* Get flash device data */
>  	for_each_available_child_of_node(dev->of_node, np) {
>  		ret = of_property_read_u32(np, "reg", &cs);
> @@ -1310,7 +1317,7 @@ static int cqspi_probe(struct platform_device *pdev)
>  	struct cqspi_st *cqspi;
>  	struct resource *res;
>  	struct resource *res_ahb;
> -	unsigned long data;
> +	struct cqspi_driver_platdata *ddata;

const struct cqspi_driver_platdata *ddata;

>  	int ret;
>  	int irq;
>  
> @@ -1377,8 +1384,8 @@ static int cqspi_probe(struct platform_device *pdev)
>  	}
>  
>  	cqspi->master_ref_clk_hz = clk_get_rate(cqspi->clk);
> -	data  = (unsigned long)of_device_get_match_data(dev);
> -	if (data & CQSPI_NEEDS_WR_DELAY)
> +	ddata  = (struct cqspi_driver_platdata *)of_device_get_match_data(dev);

I would expect an implicit type cast, you can drop the explicit cast.

> +	if (ddata && (ddata->quirks & CQSPI_NEEDS_WR_DELAY))
>  		cqspi->wr_delay = 5 * DIV_ROUND_UP(NSEC_PER_SEC,
>  						   cqspi->master_ref_clk_hz);
>  
> @@ -1460,14 +1467,37 @@ static const struct dev_pm_ops cqspi__dev_pm_ops = {
>  #define CQSPI_DEV_PM_OPS	NULL
>  #endif
>  
> +#define cqspi_base_hwcaps_mask					\
> +	(SNOR_HWCAPS_READ | SNOR_HWCAPS_READ_FAST |		\
> +	SNOR_HWCAPS_READ_1_1_2 | SNOR_HWCAPS_READ_1_1_4 |	\
> +	SNOR_HWCAPS_PP)
> +
> +static const struct cqspi_driver_platdata cdns_qspi = {
> +	.hwcaps_mask = cqspi_base_hwcaps_mask,
> +};
> +
> +static const struct cqspi_driver_platdata k2g_qspi = {
> +	.hwcaps_mask = cqspi_base_hwcaps_mask,
> +	.quirks = CQSPI_NEEDS_WR_DELAY,
> +};
> +
> +static const struct cqspi_driver_platdata am654_ospi = {
> +	.hwcaps_mask = cqspi_base_hwcaps_mask | SNOR_HWCAPS_READ_1_1_8,
> +	.quirks = CQSPI_NEEDS_WR_DELAY,
> +};
> +
>  static const struct of_device_id cqspi_dt_ids[] = {
>  	{
>  		.compatible = "cdns,qspi-nor",
> -		.data = (void *)0,
> +		.data = (void *)&cdns_qspi,

You can drop the (void *) cast.

Looks good. Did you test the octal mode with mt35xu512aba? If yes, it would be
nice to specify this in the commit message.

Cheers,
ta

>  	},
>  	{
>  		.compatible = "ti,k2g-qspi",
> -		.data = (void *)CQSPI_NEEDS_WR_DELAY,
> +		.data = (void *)&k2g_qspi,
> +	},
> +	{
> +		.compatible = "ti,am654-ospi",
> +		.data = (void *)&am654_ospi,
>  	},
>  	{ /* end of table */ }
>  };
>