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

Chris Packham
2017-05-18T04:36:54Z

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@alliedtelesis.co.nz>
> ---
> .../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);
>