Re: [PATCH v2 4/4] power: reset: Add new driver for RZ/V2M PWC poweroff

[Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>]

Hi Fabrizio,

On Wed, Dec 21, 2022 at 10:09 PM Fabrizio Castro
<fabrizio.castro.jz@xxxxxxxxxxx> wrote:
> The RZ/V2M PWC IP controls external power supplies and therefore
> can turn the power supplies off when powering down the system.
>
> Add driver to poweroff the system.
>
> Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@xxxxxxxxxxx>
> ---
>
> v1->v2: Dropped OF match table and syscon as a result of the change in
>         DT model

Thanks for your patch!

> --- /dev/null
> +++ b/drivers/power/reset/rzv2m-pwc-poweroff.c
> @@ -0,0 +1,67 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2022 Renesas Electronics Corporation
> + *
> + * Reset driver for Renesas RZ/V2M External Power Sequence Controller (PWC)
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/platform_device.h>
> +#include <linux/reboot.h>
> +#include "../../mfd/rzv2m-pwc.h"
> +
> +#define PWC_PWCRST_RSTSOFTAX           0x1
> +#define PWC_PWCCKEN_ENGCKMAIN          0x1
> +#define PWC_PWCCTL_PWOFF               0x1
> +
> +struct rzv2m_pwc_poweroff_priv {
> +       void __iomem *base;
> +       struct device *dev;
> +};
> +
> +static int rzv2m_pwc_poweroff(struct sys_off_data *data)
> +{
> +       struct rzv2m_pwc_poweroff_priv *priv =
> +               (struct rzv2m_pwc_poweroff_priv *)data->cb_data;

No need for this cast.

> +
> +       writel(PWC_PWCRST_RSTSOFTAX, priv->base + PWC_PWCRST);
> +       writel(PWC_PWCCKEN_ENGCKMAIN, priv->base + PWC_PWCCKEN);
> +       writel(PWC_PWCCTL_PWOFF, priv->base + PWC_PWCCTL);
> +
> +       mdelay(150);
> +
> +       dev_err(priv->dev, "Failed to power off the system");
> +
> +       return NOTIFY_DONE;
> +}

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds