Re: [PATCH v1 3/4] irqchip: irq-mtk-cirq: Move register offsets to const array

[Marc Zyngier <maz@kernel.org>]

On Fri, 18 Nov 2022 10:06:38 +0000,
AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> wrote:
> 
> In preparation to add support for new SoCs having different register
> offsets, add an enumeration that documents registers and move the
> register offsets definitions to a u32 array.
> 
> Of course, every usage of the definitions was changed to use the
> newly introduced register offsets array.
> 
> This change brings no functional changes.
> 
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> ---
>  drivers/irqchip/irq-mtk-cirq.c | 62 ++++++++++++++++++++++++----------
>  1 file changed, 44 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/irqchip/irq-mtk-cirq.c b/drivers/irqchip/irq-mtk-cirq.c
> index 9bca0918078e..affbc0f48550 100644
> --- a/drivers/irqchip/irq-mtk-cirq.c
> +++ b/drivers/irqchip/irq-mtk-cirq.c
> @@ -15,14 +15,30 @@
>  #include <linux/slab.h>
>  #include <linux/syscore_ops.h>
>  
> -#define CIRQ_ACK	0x40
> -#define CIRQ_MASK_SET	0xc0
> -#define CIRQ_MASK_CLR	0x100
> -#define CIRQ_SENS_SET	0x180
> -#define CIRQ_SENS_CLR	0x1c0
> -#define CIRQ_POL_SET	0x240
> -#define CIRQ_POL_CLR	0x280
> -#define CIRQ_CONTROL	0x300
> +enum mtk_cirq_reg_index {
> +	CIRQ_STA = 0,

Enums starting from 0 are the default.

> +	CIRQ_ACK,
> +	CIRQ_MASK_SET,
> +	CIRQ_MASK_CLR,
> +	CIRQ_SENS_SET,
> +	CIRQ_SENS_CLR,
> +	CIRQ_POL_SET,
> +	CIRQ_POL_CLR,
> +	CIRQ_CONTROL,
> +	CIRQ_MAX

What's the use of this last constant?

> +};
> +
> +static const u32 mtk_cirq_regs_v1[] = {
> +	[CIRQ_STA]	= 0x0,
> +	[CIRQ_ACK]	= 0x40,
> +	[CIRQ_MASK_SET]	= 0xc0,
> +	[CIRQ_MASK_CLR]	= 0x100,
> +	[CIRQ_SENS_SET]	= 0x180,
> +	[CIRQ_SENS_CLR]	= 0x1c0,
> +	[CIRQ_POL_SET]	= 0x240,
> +	[CIRQ_POL_CLR]	= 0x280,
> +	[CIRQ_CONTROL]	= 0x300,
> +};
>  
>  #define CIRQ_EN	0x1
>  #define CIRQ_EDGE	0x2
> @@ -32,18 +48,20 @@ struct mtk_cirq_chip_data {
>  	void __iomem *base;
>  	unsigned int ext_irq_start;
>  	unsigned int ext_irq_end;
> +	const u32 *regs;

This is an array of *offsets*, not registers. Please name it accordingly.

>  	struct irq_domain *domain;
>  };
>  
>  static struct mtk_cirq_chip_data *cirq_data;
>  
> -static void mtk_cirq_write_mask(struct irq_data *data, unsigned int offset)
> +static void mtk_cirq_write_mask(struct irq_data *data, enum mtk_cirq_reg_index idx)
>  {
>  	struct mtk_cirq_chip_data *chip_data = data->chip_data;
>  	unsigned int cirq_num = data->hwirq;
>  	u32 mask = 1 << (cirq_num % 32);
> +	u32 reg = chip_data->regs[idx] + (cirq_num / 32) * 4;

Please provide an accessor that takes chip_data and an index, and
returns an address.

>  
> -	writel_relaxed(mask, chip_data->base + offset + (cirq_num / 32) * 4);
> +	writel_relaxed(mask, chip_data->base + reg);
>  }
>  
>  static void mtk_cirq_mask(struct irq_data *data)
> @@ -160,7 +178,7 @@ static const struct irq_domain_ops cirq_domain_ops = {
>  #ifdef CONFIG_PM_SLEEP
>  static int mtk_cirq_suspend(void)
>  {
> -	u32 value, mask;
> +	u32 value, mask, reg;
>  	unsigned int irq, hwirq_num;
>  	bool pending, masked;
>  	int i, pendret, maskret;
> @@ -200,31 +218,34 @@ static int mtk_cirq_suspend(void)
>  				continue;
>  		}
>  
> +		reg = cirq_data->regs[CIRQ_ACK] + (i / 32) * 4;
>  		mask = 1 << (i % 32);
> -		writel_relaxed(mask, cirq_data->base + CIRQ_ACK + (i / 32) * 4);
> +		writel_relaxed(mask, cirq_data->base + reg);
>  	}
>  
>  	/* set edge_only mode, record edge-triggerd interrupts */
>  	/* enable cirq */
> -	value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);
> +	reg = cirq_data->regs[CIRQ_CONTROL];
> +	value = readl_relaxed(cirq_data->base + reg);
>  	value |= (CIRQ_EDGE | CIRQ_EN);
> -	writel_relaxed(value, cirq_data->base + CIRQ_CONTROL);
> +	writel_relaxed(value, cirq_data->base + reg);
>  
>  	return 0;
>  }
>  
>  static void mtk_cirq_resume(void)
>  {
> +	u32 reg = cirq_data->regs[CIRQ_CONTROL];
>  	u32 value;
>  
>  	/* flush recorded interrupts, will send signals to parent controller */
> -	value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);
> -	writel_relaxed(value | CIRQ_FLUSH, cirq_data->base + CIRQ_CONTROL);
> +	value = readl_relaxed(cirq_data->base + reg);
> +	writel_relaxed(value | CIRQ_FLUSH, cirq_data->base + reg);
>  
>  	/* disable cirq */
> -	value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);
> +	value = readl_relaxed(cirq_data->base + reg);
>  	value &= ~(CIRQ_EDGE | CIRQ_EN);
> -	writel_relaxed(value, cirq_data->base + CIRQ_CONTROL);
> +	writel_relaxed(value, cirq_data->base + reg);
>  }
>  
>  static struct syscore_ops mtk_cirq_syscore_ops = {
> @@ -240,6 +261,9 @@ static void mtk_cirq_syscore_init(void)
>  static inline void mtk_cirq_syscore_init(void) {}
>  #endif
>  
> +static const struct of_device_id mtk_cirq_of_match[] = {
> +	{ .compatible = "mediatek,
> +

I can tell by this hunk the quality of testing this patch has
received.

>  static int __init mtk_cirq_of_init(struct device_node *node,
>  				   struct device_node *parent)
>  {
> @@ -274,6 +298,8 @@ static int __init mtk_cirq_of_init(struct device_node *node,
>  	if (ret)
>  		goto out_unmap;
>  
> +	cirq_data->regs = mtk_cirq_regs_v1;

Why isn't this obtained from the matching array?

> +
>  	irq_num = cirq_data->ext_irq_end - cirq_data->ext_irq_start + 1;
>  	domain = irq_domain_add_hierarchy(domain_parent, 0,
>  					  irq_num, node,

	M.

-- 
Without deviation from the norm, progress is not possible.