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

[Chris Packham]

On Mon, Feb 18, 2019 at 10:41 AM Chris Packham <judge.packham at gmail.com> wrote:
>
> 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.

*sigh* there is something about Mondays. To those outside of TZ +1300
sorry for the spam.

I thought I'd killed the serial port due to the clocking but this all
seems to work fine. The problem was that on my older setup I needed to
set CONFIG_BOARD_EARLY_INIT_F (it's selected automatically for MVEBU
in u-boot#master). So v4 should be good to go (barring any more review
comments).

>
> >         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
> >