From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephen Boyd <sboyd@codeaurora.org>
Subject: Re: [PATCH v5 1/2] clk: add lpc18xx creg clk driver
Date: Fri, 4 Mar 2016 09:42:01 -0800
Message-ID: <20160304174201.GH24999@codeaurora.org>
References: <1457041625-21163-1-git-send-email-manabian@gmail.com>
 <1457041625-21163-2-git-send-email-manabian@gmail.com>
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To: Joachim Eastwood <manabian@gmail.com>
Cc: mturquette@baylibre.com, linux-clk@vger.kernel.org, devicetree@vger.kernel.org
List-Id: devicetree@vger.kernel.org

On 03/03, Joachim Eastwood wrote:
> diff --git a/drivers/clk/nxp/clk-lpc18xx-creg.c b/drivers/clk/nxp/clk-lpc18xx-creg.c
> new file mode 100644
> index 000000000000..d44b61afa2dc
> --- /dev/null
> +++ b/drivers/clk/nxp/clk-lpc18xx-creg.c
> @@ -0,0 +1,226 @@
> +
> +static int clk_creg_32k_is_prepared(struct clk_hw *hw)
> +{
> +	struct clk_creg_data *creg = to_clk_creg(hw);
> +	u32 reg;
> +
> +	regmap_read(creg->reg, LPC18XX_CREG_CREG0, &reg);
> +
> +	return !(reg & LPC18XX_CREG_CREG0_PD32KHZ) &&
> +	       !(reg & LPC18XX_CREG_CREG0_RESET32KHZ);
> +}
> +
> +static unsigned long clk_creg_1k_recalc_rate(struct clk_hw *hw,
> +					     unsigned long parent_rate)
> +{
> +	return parent_rate / 32;
> +}
> +
> +static int clk_creg_enable(struct clk_hw *hw)
> +{
> +	struct clk_creg_data *creg = to_clk_creg(hw);
> +
> +	return regmap_update_bits(creg->reg, LPC18XX_CREG_CREG0,
> +				  creg->en_mask, creg->en_mask);

Have you tested this with CONFIG_DEBUG_ATOMIC_SLEEP=y? I seem to
recall that syscon uses a regmap with regmap_config::fast_io set
to false, so all regmap operations take a mutex lock.
clk_ops::enable is called with a spinlock held, so that isn't
going to work well.

-- 
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