linux-kernel - Re: [PATCH v2 4/6] clk: stm32f4: Add RTC clock

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Date:   Wed, 19 Oct 2016 13:45:37 -0700
From:   Stephen Boyd <sboyd@...eaurora.org>
To:     gabriel.fernandez@...com
Cc:     Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Russell King <linux@...linux.org.uk>,
        Maxime Coquelin <mcoquelin.stm32@...il.com>,
        Alexandre Torgue <alexandre.torgue@...com>,
        Michael Turquette <mturquette@...libre.com>,
        Nicolas Pitre <nico@...aro.org>, Arnd Bergmann <arnd@...db.de>,
        daniel.thompson@...aro.org, devicetree@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        linux-clk@...r.kernel.org, ludovic.barre@...com,
        olivier.bideau@...com, amelie.delaunay@...com
Subject: Re: [PATCH v2 4/6] clk: stm32f4: Add RTC clock

On 10/14, gabriel.fernandez@...com wrote:
> @@ -310,6 +310,15 @@ static inline void enable_power_domain_write_protection(void)
>  	regmap_update_bits(pdrm, 0x00, (1 << 8), (0 << 8));
>  }
>  
> +static inline void sofware_reset_backup_domain(void)
> +{
> +	unsigned long val;
> +
> +	val = readl(base + STM32F4_RCC_BDCR);
> +	writel(val |= (1 << 16), base + STM32F4_RCC_BDCR);

Interesting C style here! Why set the bit in val that will then
be cleared in the next function call? Please just don't do it. It
would be better to do writel(val | BIT(16), ...)

> +	writel(val & ~(1 << 16), base + STM32F4_RCC_BDCR);
> +}
> +
>  struct stm32_rgate {
>  	struct	clk_hw hw;
>  	struct	clk_gate gate;
> @@ -396,6 +405,113 @@ static struct clk_hw *clk_register_rgate(struct device *dev, const char *name,
>  	return hw;
>  }
>  
> +static int cclk_gate_enable(struct clk_hw *hw)
> +{
> +	int ret;
> +
> +	disable_power_domain_write_protection();
> +
> +	ret = clk_gate_ops.enable(hw);
> +
> +	enable_power_domain_write_protection();
> +
> +	return ret;
> +}
> +
> +static void cclk_gate_disable(struct clk_hw *hw)
> +{
> +	disable_power_domain_write_protection();
> +
> +	clk_gate_ops.disable(hw);
> +
> +	enable_power_domain_write_protection();
> +}
> +
> +static int cclk_gate_is_enabled(struct clk_hw *hw)
> +{
> +	return clk_gate_ops.is_enabled(hw);
> +}
> +
> +static const struct clk_ops cclk_gate_ops = {
> +	.enable		= cclk_gate_enable,
> +	.disable	= cclk_gate_disable,
> +	.is_enabled	= cclk_gate_is_enabled,
> +};
> +
> +static u8 cclk_mux_get_parent(struct clk_hw *hw)
> +{
> +	return clk_mux_ops.get_parent(hw);
> +}
> +
> +

Weird double newline here. Please remove one.

> +static int cclk_mux_set_parent(struct clk_hw *hw, u8 index)
> +{
> +	int ret;
> +
> +	disable_power_domain_write_protection();
> +
> +	sofware_reset_backup_domain();
> +
> +	ret = clk_mux_ops.set_parent(hw, index);
> +
> +	enable_power_domain_write_protection();
> +
> +	return ret;
> +}
> +
> +

Same.

> +static const struct clk_ops cclk_mux_ops = {
> +	.get_parent = cclk_mux_get_parent,
> +	.set_parent = cclk_mux_set_parent,
> +};
> +
> +static struct clk_hw *stm32_register_cclk(struct device *dev, const char *name,
> +		const char * const *parent_names, int num_parents,
> +		void __iomem *reg, u8 bit_idx, u8 shift, unsigned long flags,
> +		spinlock_t *lock)
> +{
> +	struct clk_hw *hw;
> +	struct clk_gate *gate;
> +	struct clk_mux *mux;
> +
> +	gate = kzalloc(sizeof(struct clk_gate), GFP_KERNEL);

sizeof(*gate) please.

> +	if (!gate) {
> +		hw = ERR_PTR(-EINVAL);
> +		goto fail;
> +	}
> +
> +	mux = kzalloc(sizeof(struct clk_mux), GFP_KERNEL);

sizeof(*mux) please.

> +	if (!mux) {
> +		kfree(gate);
> +		hw = ERR_PTR(-EINVAL);
> +		goto fail;
> +	}
> +

-- 
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