On Fri, Aug 16, 2013 at 11:19:42AM +0400, Alexander Shiyan wrote:
> This patch adds a property to automatically determine the NAND
> bus width. This property works if the bus width is not specified
> explicitly.
>
> Signed-off-by: Alexander Shiyan <shc_work@xxxxxxx>
> ---
> .../devicetree/bindings/mtd/gpio-control-nand.txt | 2 ++
> drivers/mtd/nand/gpio.c | 16 ++++++++++++----
> 2 files changed, 14 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/mtd/gpio-control-nand.txt b/Documentation/devicetree/bindings/mtd/gpio-control-nand.txt
> index 36ef07d..91070d0 100644
> --- a/Documentation/devicetree/bindings/mtd/gpio-control-nand.txt
> +++ b/Documentation/devicetree/bindings/mtd/gpio-control-nand.txt
> @@ -19,6 +19,8 @@ Optional properties:
> defaults to 1 byte.
> - chip-delay : chip dependent delay for transferring data from array to
> read registers (tR). If not present then a default of 20us is used.
> +- gpio-control-nand,bank-width-auto : Device bus width is determined
> + automatically if "bank-width" is omitted (Boolean).
> - gpio-control-nand,io-sync-reg : A 64-bit physical address for a read
> location used to guard against bus reordering with regards to accesses to
> the GPIO's and the NAND flash data bus. If present, then after changing
> diff --git a/drivers/mtd/nand/gpio.c b/drivers/mtd/nand/gpio.c
> index e826f89..8eea181 100644
> --- a/drivers/mtd/nand/gpio.c
> +++ b/drivers/mtd/nand/gpio.c
> @@ -116,6 +116,10 @@ static int gpio_nand_get_config_of(const struct device *dev,
> dev_err(dev, "invalid bank-width %u\n", val);
> return -EINVAL;
> }
> + } else {
Combine with the 'if' and make it 'else if'.
> + if (of_get_property(dev->of_node,
> + "gpio-control-nand,bank-width-auto", NULL))
of_property_read_bool()
> + plat->options |= NAND_BUSWIDTH_AUTO;
> }
>
> plat->gpio_rdy = of_get_gpio(dev->of_node, 0);
> @@ -223,6 +227,14 @@ static int gpio_nand_probe(struct platform_device *pdev)
> if (IS_ERR(chip->IO_ADDR_R))
> return PTR_ERR(chip->IO_ADDR_R);
>
> + ret = gpio_nand_get_config(&pdev->dev, &gpiomtd->plat);
> + if (ret)
> + return ret;
> +
> + if (resource_size(res) < 2)
> + gpiomtd->plat.options &= ~(NAND_BUSWIDTH_16 |
> + NAND_BUSWIDTH_AUTO);
I can't quite figure out what the significance of resource_size(res) < 2
is. It doesn't quite match my reading of the device-tree documentation.
Maybe I'm being dense. Is the resource provided as either an 8-bit IO
address (length=1) or 16-bit IO address (length=2)?
> +
> res = gpio_nand_get_io_sync(pdev);
> if (res) {
> gpiomtd->io_sync = devm_ioremap_resource(&pdev->dev, res);
> @@ -230,10 +242,6 @@ static int gpio_nand_probe(struct platform_device *pdev)
> return PTR_ERR(gpiomtd->io_sync);
> }
>
> - ret = gpio_nand_get_config(&pdev->dev, &gpiomtd->plat);
> - if (ret)
> - return ret;
> -
> ret = devm_gpio_request(&pdev->dev, gpiomtd->plat.gpio_nce, "NAND NCE");
> if (ret)
> return ret;
I can fixup the first 2 without a resend. Depending on your response to
the third comment, I'll apply this.
Thanks,
Brian
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