[U-Boot] [PATCH v4 2/3] watchdog: orion_wdt: take timeout value in ms

[Chris Packham]

On Mon, Feb 18, 2019 at 10:31 AM Chris Packham <judge.packham at gmail.com> wrote:
>
> The generic wdt_start API expects to be called with the timeout in
> milliseconds. Update the orion_wdt driver to accept a timeout in
> milliseconds and use the clock rate specified in the dts to convert the
> timeout to an appropriate value for the timer reload register.
>
> Signed-off-by: Chris Packham <judge.packham at gmail.com>
> ---
> It turned out to be easy enough to make orion_wdt conform to the
> expected wdt APIs. It looks like the turris_mox already assumed a
> timeout in ms, so only the turris_omnia needed updating.
>
> Changes in v4:
> - use DIV_ROUND_UP to avoid setting the timeout to 0.
>
> Changes in v3:
> - new
>
> Changes in v2: None
>
>  board/CZ.NIC/turris_omnia/turris_omnia.c |  2 +-
>  drivers/watchdog/Kconfig                 |  1 +
>  drivers/watchdog/orion_wdt.c             | 23 +++++++++++++++++++----
>  3 files changed, 21 insertions(+), 5 deletions(-)
>
> diff --git a/board/CZ.NIC/turris_omnia/turris_omnia.c b/board/CZ.NIC/turris_omnia/turris_omnia.c
> index 1f7650cb3610..5e0b686c597d 100644
> --- a/board/CZ.NIC/turris_omnia/turris_omnia.c
> +++ b/board/CZ.NIC/turris_omnia/turris_omnia.c
> @@ -379,7 +379,7 @@ int board_init(void)
>                 puts("Cannot find Armada 385 watchdog!\n");
>         } else {
>                 puts("Enabling Armada 385 watchdog.\n");
> -               wdt_start(watchdog_dev, (u32) 25000000 * 120, 0);
> +               wdt_start(watchdog_dev, 120000, 0);
>         }
>  # endif
>
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index 115fc4551ffd..7f7bc4bbc494 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -97,6 +97,7 @@ config WDT_BCM6345
>  config WDT_ORION
>         bool "Orion watchdog timer support"
>         depends on WDT
> +       select CLK

Actually I just realised I can't do this yet. The armada-38x lacks a
clock driver. So while the fixed-rate clock for the watchdog works
fine. Enabling CONFIG_CLK causes the uart to not work because it can't
look up it's clock. This is not initially noticeable because the SPL
sets up the hardware but if you try to change the baudrate things get
upset.

I'm running out of u-boot hacking time to attempt to port the
armada-38x clock code from Linux. For now I'll send a quick v5 that
removes this select.

>         help
>            Select this to enable Orion watchdog timer, which can be found on some
>            Marvell Armada chips.
> diff --git a/drivers/watchdog/orion_wdt.c b/drivers/watchdog/orion_wdt.c
> index c1add3e7c121..885821d562ea 100644
> --- a/drivers/watchdog/orion_wdt.c
> +++ b/drivers/watchdog/orion_wdt.c
> @@ -14,7 +14,9 @@
>
>  #include <common.h>
>  #include <dm.h>
> +#include <clk.h>
>  #include <wdt.h>
> +#include <linux/kernel.h>
>  #include <asm/io.h>
>  #include <asm/arch/cpu.h>
>  #include <asm/arch/soc.h>
> @@ -27,6 +29,8 @@ struct orion_wdt_priv {
>         void __iomem *rstout;
>         void __iomem *rstout_mask;
>         u32 timeout;
> +       unsigned long clk_rate;
> +       struct clk clk;
>  };
>
>  #define RSTOUT_ENABLE_BIT              BIT(8)
> @@ -44,17 +48,18 @@ static int orion_wdt_reset(struct udevice *dev)
>         struct orion_wdt_priv *priv = dev_get_priv(dev);
>
>         /* Reload watchdog duration */
> -       writel(priv->timeout, priv->reg + priv->wdt_counter_offset);
> +       writel(priv->clk_rate * priv->timeout,
> +              priv->reg + priv->wdt_counter_offset);
>
>         return 0;
>  }
>
> -static int orion_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
> +static int orion_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
>  {
>         struct orion_wdt_priv *priv = dev_get_priv(dev);
>         u32 reg;
>
> -       priv->timeout = (u32) timeout;
> +       priv->timeout = DIV_ROUND_UP(timeout_ms, 1000);
>
>         /* Enable the fixed watchdog clock input */
>         reg = readl(priv->reg + TIMER_CTRL);
> @@ -62,7 +67,8 @@ static int orion_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
>         writel(reg, priv->reg + TIMER_CTRL);
>
>         /* Set watchdog duration */
> -       writel(priv->timeout, priv->reg + priv->wdt_counter_offset);
> +       writel(priv->clk_rate * priv->timeout,
> +              priv->reg + priv->wdt_counter_offset);
>
>         /* Clear the watchdog expiration bit */
>         reg = readl(priv->reg + TIMER_A370_STATUS);
> @@ -147,9 +153,18 @@ err:
>
>  static int orion_wdt_probe(struct udevice *dev)
>  {
> +       struct orion_wdt_priv *priv = dev_get_priv(dev);
> +       int ret;
> +
>         debug("%s: Probing wdt%u\n", __func__, dev->seq);
>         orion_wdt_stop(dev);
>
> +       ret = clk_get_by_name(dev, "fixed", &priv->clk);
> +       if (!ret)
> +               priv->clk_rate = clk_get_rate(&priv->clk);
> +       else
> +               priv->clk_rate = 25000000;
> +
>         return 0;
>  }
>
> --
> 2.20.1
>