[PATCH v2 03/15] watchdog: orion: Use atomic access for shared registers

On Tue, Jan 21, 2014 at 10:54:37AM +0100, Arnd Bergmann wrote:

On Tuesday 21 January 2014 06:12:29 Ezequiel Garcia wrote:

quoted

        writel(~WDT_INT_REQ, BRIDGE_CAUSE);
 
        /* Enable watchdog timer */
-       reg = readl(wdt_reg + TIMER_CTRL);
-       reg |= WDT_EN;
-       writel(reg, wdt_reg + TIMER_CTRL);
+       atomic_io_modify(wdt_reg + TIMER_CTRL, WDT_EN, WDT_EN);

As mentioned in my comment for patch 2, it seems that the exported
orion_timer_ctrl_clrset() function would be more appropriate for this.

Hi Arnd

As Sebastian points out, Armada 370 XP does not have this function. 

quoted

        /* Enable reset on watchdog */
-       reg = readl(RSTOUTn_MASK);
-       reg |= WDT_RESET_OUT_EN;
-       writel(reg, RSTOUTn_MASK);
+       atomic_io_modify(RSTOUTn_MASK, WDT_RESET_OUT_EN, WDT_RESET_OUT_EN);

And this register already has an abstraction in
arch/arm/mach-mvebu/system-controller.c. I would prefer to find a way
to generalize that. I can see multiple ways to do that:

Please be aware that arch/arm/mach-mvebu/system-controller.c is
currently DT only. We need a solution which works for both with DT and
without DT, since orion5x and mv78xx0 none DT boards are not going
away soon.

     Andrew