Re: [PATCH v1 2/5] mtd: atmel_nand: Support variable RB_EDGE interrupts

[Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>]

Hi Romain,

On Wed, 13 Jan 2016 17:34:14 +0100
Romain Izard <romain.izard.pro-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:

> The NFC controller used to accelerate the NAND transfers on SAMA5 chips
> can use either RB_EDGE0 or RB_EDGE3 as its ready/busy interrupt bit.
> 
> Use the controller's compatible string to select the correct bit.
> 
> Signed-off-by: Romain Izard <romain.izard.pro-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> Reviewed-by: Wenyou Yang <Wenyou.yang-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
> ---
>  .../devicetree/bindings/mtd/atmel-nand.txt         |  2 +-
>  drivers/mtd/nand/atmel_nand.c                      | 39 +++++++++++++++++-----
>  drivers/mtd/nand/atmel_nand_nfc.h                  |  5 ++-
>  3 files changed, 36 insertions(+), 10 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/mtd/atmel-nand.txt b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
> index 7d4c8eb775a5..89b0db9801b0 100644
> --- a/Documentation/devicetree/bindings/mtd/atmel-nand.txt
> +++ b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
> @@ -34,7 +34,7 @@ Optional properties:
>  - nand-on-flash-bbt: boolean to enable on flash bbt option if not present false
>  - Nand Flash Controller(NFC) is a slave driver under Atmel nand flash
>    - Required properties:
> -    - compatible : "atmel,sama5d3-nfc".
> +    - compatible : "atmel,sama5d3-nfc" or "atmel,sama5d4-nfc".
>      - reg : should specify the address and size used for NFC command registers,
>              NFC registers and NFC Sram. NFC Sram address and size can be absent
>              if don't want to use it.
> diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
> index 9d71f9e6a8de..e5d7e7e63f49 100644
> --- a/drivers/mtd/nand/atmel_nand.c
> +++ b/drivers/mtd/nand/atmel_nand.c
> @@ -67,6 +67,10 @@ struct atmel_nand_caps {
>  	bool pmecc_correct_erase_page;
>  };
>  
> +struct atmel_nand_nfc_priv {

Can you rename this struct into atmel_nfc_caps to be consistant with the
atmel_nand_caps?

> +	uint32_t rb_edge;

Actually, AFAIU, it's not encoding the type of edges, but the available
native R/B lines (by native I mean the R/B lines directly connected to
the NFC IP).
I suggest renaming this field avail_rb_lines, and making it a bitfield
(one bit per possible R/B line).

> +};
> +
>  /* oob layout for large page size
>   * bad block info is on bytes 0 and 1
>   * the bytes have to be consecutives to avoid
> @@ -111,6 +115,7 @@ struct atmel_nfc {
>  	/* Point to the sram bank which include readed data via NFC */
>  	void			*data_in_sram;
>  	bool			will_write_sram;
> +	uint32_t		rb_edge;

Replace this by
	const struct atmel_nfc_caps *caps;

so that next time you have a per-SoC particularity, you can just add it
to your struct atmel_nfc_caps without adding new fields to atmel_nfc.

>  };
>  static struct atmel_nfc	nand_nfc;
>  
> @@ -1675,9 +1680,9 @@ static irqreturn_t hsmc_interrupt(int irq, void *dev_id)
>  		nfc_writel(host->nfc->hsmc_regs, IDR, NFC_SR_XFR_DONE);
>  		ret = IRQ_HANDLED;
>  	}
> -	if (pending & NFC_SR_RB_EDGE) {
> +	if (pending & host->nfc->rb_edge) {
>  		complete(&host->nfc->comp_ready);
> -		nfc_writel(host->nfc->hsmc_regs, IDR, NFC_SR_RB_EDGE);
> +		nfc_writel(host->nfc->hsmc_regs, IDR, host->nfc->rb_edge);

How about creating a macro that would generate the appropriate bitmask
for you?

Something like

#define NFC_SR_RB_EDGE_MASK(x)	((x) << 24)

>  		ret = IRQ_HANDLED;
>  	}
>  	if (pending & NFC_SR_CMD_DONE) {
> @@ -1695,7 +1700,7 @@ static void nfc_prepare_interrupt(struct atmel_nand_host *host, u32 flag)
>  	if (flag & NFC_SR_XFR_DONE)
>  		init_completion(&host->nfc->comp_xfer_done);
>  
> -	if (flag & NFC_SR_RB_EDGE)
> +	if (flag & host->nfc->rb_edge)
>  		init_completion(&host->nfc->comp_ready);
>  
>  	if (flag & NFC_SR_CMD_DONE)
> @@ -1713,7 +1718,7 @@ static int nfc_wait_interrupt(struct atmel_nand_host *host, u32 flag)
>  	if (flag & NFC_SR_XFR_DONE)
>  		comp[index++] = &host->nfc->comp_xfer_done;
>  
> -	if (flag & NFC_SR_RB_EDGE)
> +	if (flag & host->nfc->rb_edge)
>  		comp[index++] = &host->nfc->comp_ready;
>  
>  	if (flag & NFC_SR_CMD_DONE)
> @@ -1781,7 +1786,7 @@ static int nfc_device_ready(struct mtd_info *mtd)
>  		dev_err(host->dev, "Lost the interrupt flags: 0x%08x\n",
>  				mask & status);
>  
> -	return status & NFC_SR_RB_EDGE;
> +	return status & host->nfc->rb_edge;
>  }
>  
>  static void nfc_select_chip(struct mtd_info *mtd, int chip)
> @@ -1954,8 +1959,8 @@ static void nfc_nand_command(struct mtd_info *mtd, unsigned int command,
>  		}
>  		/* fall through */
>  	default:
> -		nfc_prepare_interrupt(host, NFC_SR_RB_EDGE);
> -		nfc_wait_interrupt(host, NFC_SR_RB_EDGE);
> +		nfc_prepare_interrupt(host, host->nfc->rb_edge);
> +		nfc_wait_interrupt(host, host->nfc->rb_edge);
>  	}
>  }
>  
> @@ -2318,9 +2323,12 @@ static const struct of_device_id atmel_nand_dt_ids[] = {
>  
>  MODULE_DEVICE_TABLE(of, atmel_nand_dt_ids);
>  
> +static const struct of_device_id atmel_nand_nfc_match[];
> +
>  static int atmel_nand_nfc_probe(struct platform_device *pdev)
>  {
>  	struct atmel_nfc *nfc = &nand_nfc;
> +	const struct atmel_nand_nfc_priv *priv;
>  	struct resource *nfc_cmd_regs, *nfc_hsmc_regs, *nfc_sram;
>  	int ret;
>  
> @@ -2352,6 +2360,12 @@ static int atmel_nand_nfc_probe(struct platform_device *pdev)
>  		}
>  	}
>  
> +	priv = of_match_device(atmel_nand_nfc_match, &pdev->dev)->data;
> +	if (NULL == priv)
> +		return -ENODEV;
> +
> +	nfc->rb_edge = priv->rb_edge;
> +
>  	nfc_writel(nfc->hsmc_regs, IDR, 0xffffffff);
>  	nfc_readl(nfc->hsmc_regs, SR);	/* clear the NFC_SR */
>  
> @@ -2380,8 +2394,17 @@ static int atmel_nand_nfc_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> +static struct atmel_nand_nfc_priv sama5d3_nfc_priv = {
> +	.rb_edge = NFC_SR_RB_EDGE0,
> +};
> +
> +static struct atmel_nand_nfc_priv sama5d4_nfc_priv = {
> +	.rb_edge = NFC_SR_RB_EDGE3,
> +};
> +
>  static const struct of_device_id atmel_nand_nfc_match[] = {
> -	{ .compatible = "atmel,sama5d3-nfc" },
> +	{ .compatible = "atmel,sama5d3-nfc", .data = &sama5d3_nfc_priv },
> +	{ .compatible = "atmel,sama5d4-nfc", .data = &sama5d4_nfc_priv },
>  	{ /* sentinel */ }
>  };
>  MODULE_DEVICE_TABLE(of, atmel_nand_nfc_match);
> diff --git a/drivers/mtd/nand/atmel_nand_nfc.h b/drivers/mtd/nand/atmel_nand_nfc.h
> index 4d5d26221a7e..2cd9c57b1e53 100644
> --- a/drivers/mtd/nand/atmel_nand_nfc.h
> +++ b/drivers/mtd/nand/atmel_nand_nfc.h
> @@ -42,7 +42,10 @@
>  #define		NFC_SR_UNDEF		(1 << 21)
>  #define		NFC_SR_AWB		(1 << 22)
>  #define		NFC_SR_ASE		(1 << 23)
> -#define		NFC_SR_RB_EDGE		(1 << 24)
> +#define		NFC_SR_RB_EDGE0		(1 << 24)
> +#define		NFC_SR_RB_EDGE1		(1 << 25)
> +#define		NFC_SR_RB_EDGE2		(1 << 26)
> +#define		NFC_SR_RB_EDGE3		(1 << 27)

Please replace those 4 definitions by:

#define			NFC_SR_RB_EDGE(x)	BIT(x + 24)

>  
>  #define ATMEL_HSMC_NFC_IER	0x0c
>  #define ATMEL_HSMC_NFC_IDR	0x10

Best Regards,

Boris

-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
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