Re: [PATCH 01/14] qcom: mtd: nand: Add driver data for QPIC DMA

[Archit Taneja <architt@codeaurora.org>]

On 06/29/2017 12:45 PM, Abhishek Sahu wrote:
> The current driver only support EBI2 NAND which uses ADM DMA. The
> latest QCOM controller supports QPIC NAND which uses BAM DMA. NAND
> registers and programming sequence are same for EBI2 and QPIC
> NAND so the same driver can support QPIC NAND also by adding the
> BAM DMA support. This patch adds the QPIC NAND support in current
> NAND driver with compatible string "qcom,qpic-nandc-v1.4.0" and
> maps it with different configuration parameter in driver data.
> 
> Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
> ---
>   .../devicetree/bindings/mtd/qcom_nandc.txt         | 41 +++++++++++++++++++++-
>   drivers/mtd/nand/qcom_nandc.c                      | 37 ++++++++++++++++---
>   2 files changed, 73 insertions(+), 5 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/mtd/qcom_nandc.txt b/Documentation/devicetree/bindings/mtd/qcom_nandc.txt
> index 70dd511..5d0f7ae 100644
> --- a/Documentation/devicetree/bindings/mtd/qcom_nandc.txt
> +++ b/Documentation/devicetree/bindings/mtd/qcom_nandc.txt
> @@ -1,7 +1,9 @@
>   * Qualcomm NAND controller
>   
>   Required properties:
> -- compatible:		should be "qcom,ipq806x-nand"

Since you're changing the compatible string, could you mention in the commit message that
it's okay to do so since there aren't any upstream dtsi files using this binding?

> +- compatible:		must be one of the following:
> +	* "qcom,ebi2-nandc" - EBI2 NAND which uses ADM DMA like IPQ8064.

Are we sure that all EBI2 based NAND controllers would work by this single binding?
Should we put a version here too like we've done for QPIC?

> +	* "qcom,qpic-nandc-v1.4.0" - QPIC NAND v1.4.0 which uses BAM DMA like IPQ4019.
>   - reg:			MMIO address range
>   - clocks:		must contain core clock and always on clock
>   - clock-names:		must contain "core" for the core clock and "aon" for the
> @@ -84,3 +86,40 @@ nand@1ac00000 {
>   		};
>   	};
>   };
> +
> +nand@79b0000 {
> +	compatible = "qcom,qpic-nandc-v1.4.0";
> +	reg = <0x79b0000 0x1000>;
> +
> +	clocks = <&gcc GCC_QPIC_CLK>,
> +		<&gcc GCC_QPIC_AHB_CLK>;
> +	clock-names = "core", "aon";
> +
> +	#address-cells = <1>;
> +	#size-cells = <0>;
> +
> +	nandcs@0 {
> +		compatible = "qcom,nandcs";
> +		reg = <0>;
> +
> +		nand-ecc-strength = <4>;
> +		nand-ecc-step-size = <512>;
> +		nand-bus-width = <8>;
> +
> +		partitions {
> +			compatible = "fixed-partitions";
> +			#address-cells = <1>;
> +			#size-cells = <1>;
> +
> +			partition@0 {
> +				label = "boot-nand";
> +				reg = <0 0x58a0000>;
> +			};
> +
> +			partition@58a0000 {
> +				label = "fs-nand";
> +				reg = <0x58a0000 0x4000000>;
> +			};
> +		};
> +	};
> +};
> diff --git a/drivers/mtd/nand/qcom_nandc.c b/drivers/mtd/nand/qcom_nandc.c
> index 57d483a..f55f728 100644
> --- a/drivers/mtd/nand/qcom_nandc.c
> +++ b/drivers/mtd/nand/qcom_nandc.c
> @@ -1,5 +1,5 @@
>   /*
> - * Copyright (c) 2016, The Linux Foundation. All rights reserved.
> + * Copyright (c) 2016-2017, The Linux Foundation. All rights reserved.
>    *
>    * This software is licensed under the terms of the GNU General Public
>    * License version 2, as published by the Free Software Foundation, and
> @@ -234,6 +234,8 @@ struct nandc_regs {
>    * @cmd1/vld:			some fixed controller register values
>    * @ecc_modes:			supported ECC modes by the current controller,
>    *				initialized via DT match data
> + * @dma_bam_enabled:		flag to tell whether nand controller is using
> + *				bam dma
>    */
>   struct qcom_nand_controller {
>   	struct nand_hw_control controller;
> @@ -253,6 +255,7 @@ struct qcom_nand_controller {
>   	struct list_head desc_list;
>   
>   	u8		*data_buffer;
> +	bool		dma_bam_enabled;
>   	int		buf_size;
>   	int		buf_count;
>   	int		buf_start;
> @@ -316,6 +319,17 @@ struct qcom_nand_host {
>   	u32 clrreadstatus;
>   };
>   
> +/*
> + * This data type corresponds to the nand driver data which will be used at
> + * driver probe time
> + * @ecc_modes - ecc mode for nand
> + * @dma_bam_enabled - whether this driver is using bam
> + */
> +struct qcom_nand_driver_data {
> +	u32 ecc_modes;
> +	bool dma_bam_enabled;
> +};
> +
>   static inline struct qcom_nand_host *to_qcom_nand_host(struct nand_chip *chip)
>   {
>   	return container_of(chip, struct qcom_nand_host, chip);
> @@ -2073,6 +2087,7 @@ static int qcom_nandc_probe(struct platform_device *pdev)
>   	struct device_node *dn = dev->of_node, *child;
>   	struct resource *res;
>   	int ret;
> +	const struct qcom_nand_driver_data *driver_data;
>   
>   	nandc = devm_kzalloc(&pdev->dev, sizeof(*nandc), GFP_KERNEL);
>   	if (!nandc)
> @@ -2087,7 +2102,10 @@ static int qcom_nandc_probe(struct platform_device *pdev)
>   		return -ENODEV;
>   	}
>   
> -	nandc->ecc_modes = (unsigned long)dev_data;
> +	driver_data = (const struct qcom_nand_driver_data *)dev_data;
> +
> +	nandc->ecc_modes = driver_data->ecc_modes;
> +	nandc->dma_bam_enabled = driver_data->dma_bam_enabled;
>   
>   	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>   	nandc->base = devm_ioremap_resource(dev, res);
> @@ -2179,15 +2197,26 @@ static int qcom_nandc_remove(struct platform_device *pdev)
>   	return 0;
>   }
>   
> -#define EBI2_NANDC_ECC_MODES	(ECC_RS_4BIT | ECC_BCH_8BIT)
>   
> +static const struct qcom_nand_driver_data ebi2_nandc_data = {
> +	.ecc_modes = (ECC_RS_4BIT | ECC_BCH_8BIT),
> +	.dma_bam_enabled = false,
> +};
> +
> +static const struct qcom_nand_driver_data qpic_nandc_v1_4_0_data = {
> +	.ecc_modes = (ECC_BCH_4BIT | ECC_BCH_8BIT),
> +	.dma_bam_enabled = true,
> +};
>   /*
>    * data will hold a struct pointer containing more differences once we support
>    * more controller variants
>    */
>   static const struct of_device_id qcom_nandc_of_match[] = {
>   	{	.compatible = "qcom,ipq806x-nand",

Please make sure that you update the compatible string above too.

Thanks,
Archit

> -		.data = (void *)EBI2_NANDC_ECC_MODES,
> +		.data = (void *)&ebi2_nandc_data,
> +	},
> +	{	.compatible = "qcom,qpic-nandc-v1.4.0",
> +		.data = (void *)&qpic_nandc_v1_4_0_data,
>   	},
>   	{}
>   };
> 

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