On Thu, 28 Sep 2017 11:46:23 +0200
Romain Izard <romain.izard.pro@xxxxxxxxx> wrote:
> During backup mode, the contents of all registers will be cleared as the
> SoC will be completely powered down. For a product that boots on NAND
> Flash memory, the bootloader will obviously use the related controller
> to read the Flash and correct any detected error in the memory, before
> handling back control to the kernel's resuming entry point.
>
> But it does not clean the NAND controller registers after use and on its
> side the kernel driver expects the error locator to be powered down and
> in a clean state. Add a resume hook for the PMECC error locator, and
> reset its registers.
>
> Signed-off-by: Romain Izard <romain.izard.pro@xxxxxxxxx>
Applied.
Thanks,
Boris
> ---
> Changes in v3:
> * keep the PMECC disabled when not in use, and use atmel_pmecc_resume to
> reset the controller after the bootloader has left it enabled.
>
> Changes in v4:
> * export atmel_pmecc_reset instead of atmel_pmecc_resume
> * use the correct pointer in atmel_nand_controller_resume
>
> drivers/mtd/nand/atmel/nand-controller.c | 3 +++
> drivers/mtd/nand/atmel/pmecc.c | 17 +++++++++--------
> drivers/mtd/nand/atmel/pmecc.h | 1 +
> 3 files changed, 13 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/mtd/nand/atmel/nand-controller.c b/drivers/mtd/nand/atmel/nand-controller.c
> index f25eca79f4e5..8afcff9a66ea 100644
> --- a/drivers/mtd/nand/atmel/nand-controller.c
> +++ b/drivers/mtd/nand/atmel/nand-controller.c
> @@ -2530,6 +2530,9 @@ static __maybe_unused int atmel_nand_controller_resume(struct device *dev)
> struct atmel_nand_controller *nc = dev_get_drvdata(dev);
> struct atmel_nand *nand;
>
> + if (nc->pmecc)
> + atmel_pmecc_reset(nc->pmecc);
> +
> list_for_each_entry(nand, &nc->chips, node) {
> int i;
>
> diff --git a/drivers/mtd/nand/atmel/pmecc.c b/drivers/mtd/nand/atmel/pmecc.c
> index 146af8218314..0a3f12141c45 100644
> --- a/drivers/mtd/nand/atmel/pmecc.c
> +++ b/drivers/mtd/nand/atmel/pmecc.c
> @@ -765,6 +765,13 @@ void atmel_pmecc_get_generated_eccbytes(struct atmel_pmecc_user *user,
> }
> EXPORT_SYMBOL_GPL(atmel_pmecc_get_generated_eccbytes);
>
> +void atmel_pmecc_reset(struct atmel_pmecc *pmecc)
> +{
> + writel(PMECC_CTRL_RST, pmecc->regs.base + ATMEL_PMECC_CTRL);
> + writel(PMECC_CTRL_DISABLE, pmecc->regs.base + ATMEL_PMECC_CTRL);
> +}
> +EXPORT_SYMBOL_GPL(atmel_pmecc_reset);
> +
> int atmel_pmecc_enable(struct atmel_pmecc_user *user, int op)
> {
> struct atmel_pmecc *pmecc = user->pmecc;
> @@ -797,10 +804,7 @@ EXPORT_SYMBOL_GPL(atmel_pmecc_enable);
>
> void atmel_pmecc_disable(struct atmel_pmecc_user *user)
> {
> - struct atmel_pmecc *pmecc = user->pmecc;
> -
> - writel(PMECC_CTRL_RST, pmecc->regs.base + ATMEL_PMECC_CTRL);
> - writel(PMECC_CTRL_DISABLE, pmecc->regs.base + ATMEL_PMECC_CTRL);
> + atmel_pmecc_reset(user->pmecc);
> mutex_unlock(&user->pmecc->lock);
> }
> EXPORT_SYMBOL_GPL(atmel_pmecc_disable);
> @@ -855,10 +859,7 @@ static struct atmel_pmecc *atmel_pmecc_create(struct platform_device *pdev,
>
> /* Disable all interrupts before registering the PMECC handler. */
> writel(0xffffffff, pmecc->regs.base + ATMEL_PMECC_IDR);
> -
> - /* Reset the ECC engine */
> - writel(PMECC_CTRL_RST, pmecc->regs.base + ATMEL_PMECC_CTRL);
> - writel(PMECC_CTRL_DISABLE, pmecc->regs.base + ATMEL_PMECC_CTRL);
> + atmel_pmecc_reset(pmecc);
>
> return pmecc;
> }
> diff --git a/drivers/mtd/nand/atmel/pmecc.h b/drivers/mtd/nand/atmel/pmecc.h
> index a8ddbfca2ea5..817e0dd9fd15 100644
> --- a/drivers/mtd/nand/atmel/pmecc.h
> +++ b/drivers/mtd/nand/atmel/pmecc.h
> @@ -61,6 +61,7 @@ atmel_pmecc_create_user(struct atmel_pmecc *pmecc,
> struct atmel_pmecc_user_req *req);
> void atmel_pmecc_destroy_user(struct atmel_pmecc_user *user);
>
> +void atmel_pmecc_reset(struct atmel_pmecc *pmecc);
> int atmel_pmecc_enable(struct atmel_pmecc_user *user, int op);
> void atmel_pmecc_disable(struct atmel_pmecc_user *user);
> int atmel_pmecc_wait_rdy(struct atmel_pmecc_user *user);
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