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

Boris Brezillon
2016-01-13T18:14:33Z

Hi Romain,

On Wed, 13 Jan 2016 17:34:14 +0100
Romain Izard <romain.izard.pro@gmail.com> 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@gmail.com>
> Reviewed-by: Wenyou Yang <Wenyou.yang@atmel.com>
> ---
> .../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