Re: [PATCH 2/4] watchdog: orion: Use the reference clock on Armada 375 SoC

From: Andrew Lunn <andrew@lunn.ch>
To: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Cc: Jason Cooper <jason@lakedaemon.net>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Wim Van Sebroeck <wim@iguana.be>,
	Lior Amsalem <alior@marvell.com>,
	Thomas Petazzoni <thomas.petazzoni@free-electrons.com>,
	linux-watchdog@vger.kernel.org,
	Tawfik Bayouk <tawfik@marvell.com>,
	Nadav Haklai <nadavh@marvell.com>,
	Gregory Clement <gregory.clement@free-electrons.com>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 2/4] watchdog: orion: Use the reference clock on Armada 375 SoC
Date: Wed, 22 Oct 2014 16:02:21 +0200	[thread overview]
Message-ID: <20141022140221.GP9845@lunn.ch> (raw)
In-Reply-To: <1413984884-20273-3-git-send-email-ezequiel.garcia@free-electrons.com>

On Wed, Oct 22, 2014 at 10:34:42AM -0300, Ezequiel Garcia wrote:
> The 25 MHz reference clock has better stability so its use is preferred over the
> core clock. Changes 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.

Hi Ezequiel

There is now quite a lot of code in orion_wdt.c which is not relevant
to Orion5x and Kirkwood. Would it be possible to put some of it inside
a #ifdef MACH_MVEBU_V7?

  Andrew

> 
> Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
> ---
>  drivers/watchdog/orion_wdt.c | 40 +++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 39 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/watchdog/orion_wdt.c b/drivers/watchdog/orion_wdt.c
> index 00d0741..6452fa2 100644
> --- a/drivers/watchdog/orion_wdt.c
> +++ b/drivers/watchdog/orion_wdt.c
> @@ -114,6 +114,44 @@ 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 +432,7 @@ 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
> 
> 
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