Re: [PATCH v3 2/3] watchdog: orion: Use the reference clock on Armada 375 SoC

Wim Van Sebroeck
2014-11-25T13:30:50Z

Hi Ezequiel,

You can add my: Acked-by: Wim Van Sebroeck <wim@iguana.be>

Kind regards,
Wim.

> The 25 MHz reference clock has better stability so its use is prefered over the
> core clock. Change the Armada 375 clock initialization to use this reference
> clock. To ensure the driver is compatible with an old devicetree, also provide
> a fallback path which will silently return to the previous behavior.
>
> While here, add the clock specification to the binding documentation.
>
> Acked-by: Jason Cooper <jason@lakedaemon.net>
> Reviewed-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
> Tested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
> Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
> ---
> .../devicetree/bindings/watchdog/marvel.txt | 13 +++++++
> drivers/watchdog/orion_wdt.c | 42 +++++++++++++++++++++-
> 2 files changed, 54 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/watchdog/marvel.txt b/Documentation/devicetree/bindings/watchdog/marvel.txt
> index 97223fd..858ed92 100644
> --- a/Documentation/devicetree/bindings/watchdog/marvel.txt
> +++ b/Documentation/devicetree/bindings/watchdog/marvel.txt
> @@ -17,6 +17,18 @@ For "marvell,armada-375-wdt" and "marvell,armada-380-wdt":
> - reg : A third entry is mandatory and should contain the
> shared mask/unmask RSTOUT address.
>
> +Clocks required for compatibles = "marvell,orion-wdt",
> + "marvell,armada-370-wdt":
> +- clocks : Must contain a single entry describing the clock input
> +
> +Clocks required for compatibles = "marvell,armada-xp-wdt"
> + "marvell,armada-375-wdt"
> + "marvell,armada-380-wdt":
> +- clocks : Must contain an entry for each entry in clock-names.
> +- clock-names : Must include the following entries:
> + "nbclk" (L2/coherency fabric clock),
> + "fixed" (Reference 25 MHz fixed-clock).
> +
> Optional properties:
>
> - interrupts : Contains the IRQ for watchdog expiration
> @@ -30,4 +42,5 @@ Example:
> interrupts = <3>;
> timeout-sec = <10>;
> status = "okay";
> + clocks = <&gate_clk 7>;
> };
> diff --git a/drivers/watchdog/orion_wdt.c b/drivers/watchdog/orion_wdt.c
> index 00d0741..8cb1ff3 100644
> --- a/drivers/watchdog/orion_wdt.c
> +++ b/drivers/watchdog/orion_wdt.c
> @@ -114,6 +114,46 @@ static int armada370_wdt_clock_init(struct platform_device *pdev,
> return 0;
> }
>
> +static int armada375_wdt_clock_init(struct platform_device *pdev,
> + struct orion_watchdog *dev)
> +{
> + int ret;
> +
> + dev->clk = of_clk_get_by_name(pdev->dev.of_node, "fixed");
> + if (!IS_ERR(dev->clk)) {
> + ret = clk_prepare_enable(dev->clk);
> + if (ret) {
> + clk_put(dev->clk);
> + return ret;
> + }
> +
> + atomic_io_modify(dev->reg + TIMER_CTRL,
> + WDT_AXP_FIXED_ENABLE_BIT,
> + WDT_AXP_FIXED_ENABLE_BIT);
> + dev->clk_rate = clk_get_rate(dev->clk);
> +
> + return 0;
> + }
> +
> + /* Mandatory fallback for proper devicetree backward compatibility */
> + dev->clk = clk_get(&pdev->dev, NULL);
> + if (IS_ERR(dev->clk))
> + return PTR_ERR(dev->clk);
> +
> + ret = clk_prepare_enable(dev->clk);
> + if (ret) {
> + clk_put(dev->clk);
> + return ret;
> + }
> +
> + atomic_io_modify(dev->reg + TIMER_CTRL,
> + WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT),
> + WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT));
> + dev->clk_rate = clk_get_rate(dev->clk) / WDT_A370_RATIO;
> +
> + return 0;
> +}
> +
> static int armadaxp_wdt_clock_init(struct platform_device *pdev,
> struct orion_watchdog *dev)
> {
> @@ -394,7 +434,7 @@ static const struct orion_watchdog_data armada375_data = {
> .rstout_mask_bit = BIT(10),
> .wdt_enable_bit = BIT(8),
> .wdt_counter_offset = 0x34,
> - .clock_init = armada370_wdt_clock_init,
> + .clock_init = armada375_wdt_clock_init,
> .enabled = armada375_enabled,
> .start = armada375_start,
> .stop = armada375_stop,
> --
> 2.1.0
>