[PATCH 8/9] mtd: nand: mxc: implement onfi get/set features

[boris.brezillon@free-electrons.com (Boris Brezillon)]

Hi Sascha,

On Thu, 15 Sep 2016 10:32:52 +0200
Sascha Hauer <s.hauer@pengutronix.de> wrote:

> To be able to support different ONFI timing modes we have to implement
> the onfi_set_features and onfi_get_features. Tested on an i.MX25 SoC.
> 
> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> ---
>  drivers/mtd/nand/mxc_nand.c | 53 +++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 53 insertions(+)
> 
> diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
> index 5173fad..1db8299 100644
> --- a/drivers/mtd/nand/mxc_nand.c
> +++ b/drivers/mtd/nand/mxc_nand.c
> @@ -1239,6 +1239,57 @@ static void mxc_nand_command(struct mtd_info *mtd, unsigned command,
>  	}
>  }
>  
> +static int mxc_nand_onfi_set_features(struct mtd_info *mtd, struct nand_chip *chip,
> +			int addr, uint8_t *subfeature_param)
> +{
> +	struct nand_chip *nand_chip = mtd_to_nand(mtd);
> +	struct mxc_nand_host *host = nand_get_controller_data(nand_chip);
> +	int i;
> +
> +	if (!chip->onfi_version ||
> +	    !(le16_to_cpu(chip->onfi_params.opt_cmd)
> +	      & ONFI_OPT_CMD_SET_GET_FEATURES))
> +		return -EINVAL;
> +
> +	host->buf_start = 0;
> +
> +	for (i = 0; i < ONFI_SUBFEATURE_PARAM_LEN; ++i)
> +		chip->write_byte(mtd, subfeature_param[i]);
> +
> +	memcpy32_toio(host->main_area0, host->data_buf, mtd->writesize);
> +	host->devtype_data->send_cmd(host, NAND_CMD_SET_FEATURES, false);
> +	mxc_do_addr_cycle(mtd, addr, -1);
> +	host->devtype_data->send_page(mtd, NFC_INPUT);

I've been working with an mx27 board embedding a NAND device lately,
and had a closer look at the NAND controller IP.
With this IP, you're not able to send only 4 bytes of data, and I'm
sure sure what you're doing here (sending a full page of data) works
for a SET_FEATURE command.

Do you have a way to test it (my NAND is not ONFI compliant)? By test
it, I mean, set a timing mode using SET_FEATURE and check if the new
mode has been applied using GET_FEATURE.

> +
> +	return 0;
> +}
> +
> +static int mxc_nand_onfi_get_features(struct mtd_info *mtd, struct nand_chip *chip,
> +			int addr, uint8_t *subfeature_param)
> +{
> +	struct nand_chip *nand_chip = mtd_to_nand(mtd);
> +	struct mxc_nand_host *host = nand_get_controller_data(nand_chip);
> +	int i;
> +
> +	if (!chip->onfi_version ||
> +	    !(le16_to_cpu(chip->onfi_params.opt_cmd)
> +	      & ONFI_OPT_CMD_SET_GET_FEATURES))
> +		return -EINVAL;
> +
> +	*(uint32_t *)host->main_area0 = 0xdeadbeef;
> +
> +	host->devtype_data->send_cmd(host, NAND_CMD_GET_FEATURES, false);
> +	mxc_do_addr_cycle(mtd, addr, -1);
> +	host->devtype_data->send_page(mtd, NFC_OUTPUT);
> +	memcpy32_fromio(host->data_buf, host->main_area0, 512);
> +	host->buf_start = 0;
> +
> +	for (i = 0; i < ONFI_SUBFEATURE_PARAM_LEN; ++i)
> +		*subfeature_param++ = chip->read_byte(mtd);
> +
> +	return 0;
> +}
> +
>  /*
>   * The generic flash bbt decriptors overlap with our ecc
>   * hardware, so define some i.MX specific ones.
> @@ -1513,6 +1564,8 @@ static int mxcnd_probe(struct platform_device *pdev)
>  	this->read_word = mxc_nand_read_word;
>  	this->write_buf = mxc_nand_write_buf;
>  	this->read_buf = mxc_nand_read_buf;
> +	this->onfi_set_features = mxc_nand_onfi_set_features;
> +	this->onfi_get_features = mxc_nand_onfi_get_features;
>  
>  	host->clk = devm_clk_get(&pdev->dev, NULL);
>  	if (IS_ERR(host->clk))