Re: [PATCH v5 22/28] mtd: rawnand: Add the ->choose_data_interface() hook

From: Boris Brezillon <boris.brezillon@collabora.com>
To: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Rickard Andersson <rickaran@axis.com>,
	Richard Weinberger <richard@nod.at>,
	linux-mtd@lists.infradead.org,
	Vignesh Raghavendra <vigneshr@ti.com>,
	Tudor Ambarus <Tudor.Ambarus@microchip.com>
Subject: Re: [PATCH v5 22/28] mtd: rawnand: Add the ->choose_data_interface() hook
Date: Tue, 26 May 2020 23:52:25 +0200	[thread overview]
Message-ID: <20200526235225.6e0f0ce2@collabora.com> (raw)
In-Reply-To: <20200526191725.7591-23-miquel.raynal@bootlin.com>

On Tue, 26 May 2020 21:17:19 +0200
Miquel Raynal <miquel.raynal@bootlin.com> wrote:

> This hook can be overloaded by NAND manufacturer drivers to propose
> alternative timings when not following the main standards. In this
> case, the manufacturer drivers is responsible for choosing the best
> data interface and configuration that fits both the controller and

		  ^ s/and//

> chip capabilities.
> 
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> ---
>  drivers/mtd/nand/raw/nand_base.c | 9 +++++++--
>  include/linux/mtd/rawnand.h      | 3 +++
>  2 files changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
> index b2e833a8ab9d..f14d297c50f4 100644
> --- a/drivers/mtd/nand/raw/nand_base.c
> +++ b/drivers/mtd/nand/raw/nand_base.c
> @@ -1046,7 +1046,6 @@ int nand_choose_best_sdr_timings(struct nand_chip *chip,
>  		}
>  	}
>  
> -

Should this line removal be part of another patch?

>  	for (mode = best_mode; mode >= 0; mode--) {
>  		ret = onfi_fill_data_interface(chip, iface, NAND_SDR_IFACE,
>  					       mode);
> @@ -1068,7 +1067,9 @@ int nand_choose_best_sdr_timings(struct nand_chip *chip,
>   * @chip: The NAND chip
>   *
>   * Find the best data interface and NAND timings supported by the chip
> - * and the driver.
> + * and the driver. Eventually let the NAND manufacturer driver propose his own
> + * set of timings.
> + *
>   * After this function nand_chip->data_interface is initialized with the best
>   * timing mode available.
>   *
> @@ -1079,6 +1080,10 @@ static int nand_choose_data_interface(struct nand_chip *chip)
>  	if (!nand_controller_has_setup_data_iface(chip))
>  		return 0;
>  
> +	if (chip->ops.choose_data_interface)
> +		return chip->ops.choose_data_interface(chip,
> +						       &chip->data_interface);
> +
>  	return nand_choose_best_sdr_timings(chip, &chip->data_interface, NULL);
>  }
>  
> diff --git a/include/linux/mtd/rawnand.h b/include/linux/mtd/rawnand.h
> index 2995d29587c3..5bd79e853140 100644
> --- a/include/linux/mtd/rawnand.h
> +++ b/include/linux/mtd/rawnand.h
> @@ -1034,6 +1034,7 @@ struct nand_legacy {
>   * @lock_area: Lock operation
>   * @unlock_area: Unlock operation
>   * @setup_read_retry: Set the read-retry mode (mostly needed for MLC NANDs)
> + * @choose_data_interface: Choose the best data interface
>   */
>  struct nand_chip_ops {
>  	int (*suspend)(struct nand_chip *chip);
> @@ -1041,6 +1042,8 @@ struct nand_chip_ops {
>  	int (*lock_area)(struct nand_chip *chip, loff_t ofs, uint64_t len);
>  	int (*unlock_area)(struct nand_chip *chip, loff_t ofs, uint64_t len);
>  	int (*setup_read_retry)(struct nand_chip *chip, int retry_mode);
> +	int (*choose_data_interface)(struct nand_chip *chip,
> +				     struct nand_data_interface *iface);
>  };
>  
>  /**

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