Re: [PATCH 4/4] mtd: mchp23k256: Add support for mchp23lcv1024

[Chris Packham]

On 17/05/17 17:39, Chris Packham wrote:
> The mchp23lcv1024 is software compatible with the mchp23k256, the
> only difference (from a software point of view) is the size. There
> is no way to detect the size so we must be told via a Device Tree.


I've just noticed that another difference between the 2 chips is 16-bit 
vs 24-bit addressing. So that will also need to be handled.


> 
> Signed-off-by: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx>
> ---
>   .../bindings/mtd/microchip,mchp23k256.txt           |  2 +-
>   drivers/mtd/devices/mchp23k256.c                    | 21 +++++++++++++++++++--
>   2 files changed, 20 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/mtd/microchip,mchp23k256.txt b/Documentation/devicetree/bindings/mtd/microchip,mchp23k256.txt
> index 25e5ad38b0f0..7328eb92a03c 100644
> --- a/Documentation/devicetree/bindings/mtd/microchip,mchp23k256.txt
> +++ b/Documentation/devicetree/bindings/mtd/microchip,mchp23k256.txt
> @@ -3,7 +3,7 @@
>   Required properties:
>   - #address-cells, #size-cells : Must be present if the device has sub-nodes
>     representing partitions.
> -- compatible : Must be "microchip,mchp23k256"
> +- compatible : Must be one of "microchip,mchp23k256" or "microchip,mchp23lcv1024"
>   - reg : Chip-Select number
>   - spi-max-frequency : Maximum frequency of the SPI bus the chip can operate at
>   
> diff --git a/drivers/mtd/devices/mchp23k256.c b/drivers/mtd/devices/mchp23k256.c
> index 02c6b9dcbd3e..d1eba587633c 100644
> --- a/drivers/mtd/devices/mchp23k256.c
> +++ b/drivers/mtd/devices/mchp23k256.c
> @@ -21,6 +21,8 @@
>   #include <linux/spi/spi.h>
>   #include <linux/of_device.h>
>   
> +enum chips { mchp23k256, mchp23lcv1024 };
> +
>   struct mchp23k256_flash {
>   	struct spi_device	*spi;
>   	struct mutex		lock;
> @@ -128,6 +130,7 @@ static int mchp23k256_probe(struct spi_device *spi)
>   	struct mchp23k256_flash *flash;
>   	struct flash_platform_data *data;
>   	int err;
> +	enum chips chip;
>   
>   	flash = devm_kzalloc(&spi->dev, sizeof(*flash), GFP_KERNEL);
>   	if (!flash)
> @@ -143,15 +146,28 @@ static int mchp23k256_probe(struct spi_device *spi)
>   
>   	data = dev_get_platdata(&spi->dev);
>   
> +	if (spi->dev.of_node)
> +		chip = (enum chips)of_device_get_match_data(&spi->dev);
> +	else
> +		chip = mchp23k256;
> +
>   	mtd_set_of_node(&flash->mtd, spi->dev.of_node);
>   	flash->mtd.dev.parent	= &spi->dev;
>   	flash->mtd.type		= MTD_RAM;
>   	flash->mtd.flags	= MTD_CAP_RAM;
>   	flash->mtd.writesize	= 1;
> -	flash->mtd.size		= SZ_32K;
>   	flash->mtd._read	= mchp23k256_read;
>   	flash->mtd._write	= mchp23k256_write;
>   
> +	switch (chip){
> +	case mchp23lcv1024:
> +		flash->mtd.size		= SZ_128K;
> +		break;
> +	default:
> +		flash->mtd.size		= SZ_32K;
> +		break;
> +	}
> +
>   	flash->mtd.erasesize = PAGE_SIZE;
>   	while (flash->mtd.size & (flash->mtd.erasesize - 1))
>   		flash->mtd.erasesize >>= 1;
> @@ -172,7 +188,8 @@ static int mchp23k256_remove(struct spi_device *spi)
>   }
>   
>   static const struct of_device_id mchp23k256_of_table[] = {
> -	{ .compatible = "microchip,mchp23k256" },
> +	{ .compatible = "microchip,mchp23k256", .data = (void *)mchp23k256 },
> +	{ .compatible = "microchip,mchp23lcv1024", .data = (void *)mchp23lcv1024 },
>   	{}
>   };
>   MODULE_DEVICE_TABLE(of, mchp23k256_of_table);
>