Re: [PATCH 1/2] power: reset: at91: add sama5d3 reset function

From: Alexandre Belloni
Date: Fri Jul 10 2015 - 02:04:06 EST


Hi,

On 09/07/2015 at 18:15:46 +0800, Josh Wu wrote :
> As since sama5d3, to reset the chip, we don't need to shutdown the ddr
> controller.
>
> So add a new compatible string and new restart function for sama5d3 and
> later chips. As we don't use sama5d3 ddr controller, so remove it as
> well.
>
> Signed-off-by: Josh Wu <josh.wu@xxxxxxxxx>
> Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>
> ---
>
> drivers/power/reset/at91-reset.c | 30 +++++++++++++++++++++---------
> 1 file changed, 21 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/power/reset/at91-reset.c b/drivers/power/reset/at91-reset.c
> index 36dc52f..8944b63 100644
> --- a/drivers/power/reset/at91-reset.c
> +++ b/drivers/power/reset/at91-reset.c
> @@ -123,6 +123,14 @@ static int at91sam9g45_restart(struct notifier_block *this, unsigned long mode,
> return NOTIFY_DONE;
> }
>
> +static int sama5d3_restart(struct notifier_block *this, unsigned long mode,
> + void *cmd)

Please align that line properly.

> +{
> + writel(cpu_to_le32(AT91_RSTC_KEY | AT91_RSTC_PERRST | AT91_RSTC_PROCRST),
> + at91_rstc_base);

That one too.

> + return NOTIFY_DONE;
> +}
> +
> static void __init at91_reset_status(struct platform_device *pdev)
> {
> u32 reg = readl(at91_rstc_base + AT91_RSTC_SR);
> @@ -155,13 +163,13 @@ static void __init at91_reset_status(struct platform_device *pdev)
> static const struct of_device_id at91_ramc_of_match[] = {
> { .compatible = "atmel,at91sam9260-sdramc", },
> { .compatible = "atmel,at91sam9g45-ddramc", },
> - { .compatible = "atmel,sama5d3-ddramc", },
> { /* sentinel */ }
> };
>
> static const struct of_device_id at91_reset_of_match[] = {
> { .compatible = "atmel,at91sam9260-rstc", .data = at91sam9260_restart },
> { .compatible = "atmel,at91sam9g45-rstc", .data = at91sam9g45_restart },
> + { .compatible = "atmel,sama5d3-rstc", .data = sama5d3_restart },
> { /* sentinel */ }
> };
>
> @@ -181,17 +189,21 @@ static int at91_reset_of_probe(struct platform_device *pdev)
> return -ENODEV;
> }
>
> - for_each_matching_node(np, at91_ramc_of_match) {
> - at91_ramc_base[idx] = of_iomap(np, 0);
> - if (!at91_ramc_base[idx]) {
> - dev_err(&pdev->dev, "Could not map ram controller address\n");
> - return -ENODEV;
> + match = of_match_node(at91_reset_of_match, pdev->dev.of_node);
> + at91_restart_nb.notifier_call = match->data;
> +
> + if (match->data != sama5d3_restart) {

This doesn't scale well. I would create a structure with a pointer to
the restart function and a boolean or a bitfield to store whether the
workaround is needed. Use that structure in your match data. Then, you
won't need to reorder anything.

> + /* we need to shutdown the ddr controller, so get ramc base */
> + for_each_matching_node(np, at91_ramc_of_match) {
> + at91_ramc_base[idx] = of_iomap(np, 0);
> + if (!at91_ramc_base[idx]) {
> + dev_err(&pdev->dev, "Could not map ram controller address\n");
> + return -ENODEV;
> + }
> + idx++;
> }
> - idx++;
> }
>
> - match = of_match_node(at91_reset_of_match, pdev->dev.of_node);
> - at91_restart_nb.notifier_call = match->data;
> return register_restart_handler(&at91_restart_nb);
> }

--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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