Re: [PATCH 03/19] irqchip: atmel-aic: clean up RTT interrupt code

[Boris Brezillon <boris.brezillon@free-electrons.com>]

On Mon, 4 Jan 2016 13:28:27 +0900
Milo Kim <milo.kim@ti.com> wrote:

> Atmel AIC disables RTT(Real Time Timer) interrupt on initialization.
> Alarm interrupt(ALMIEN) and RTT increment interrupt(RTTINCIEN) are used.
> However, the controller doesn't need to do it.
> 
> * RTT driver disables interrupts on _probe().
>   ALMIEN and RTTINCIEN bits in RTT_MR are cleared to disable RTT
>   interrupts.
>   (drivers/rtc/rtc-at91sam9.c)
>   /* disable all interrupts (same as on shutdown path) */
>   mr &= ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN);
>   rtt_writel(rtc, MR, mr);
> 
> * All RTT interrupts are disabled by default.
>   Reset value of ALMIEN and RTTINCIEN bits are 0.
>   Please note that all devices have same RTT registers.
>   AT91RM9G45
>   AT91SAM9RL
>   AT91SAM9260
>   AT91SAM9261
>   AT91SAM9263
>   AT91SAM9G20
> 
> So, aic_common_rtt_irq_fixup() helper can be removed.
> And aic_common_irq_fixup() also can be removed because no driver
> calls it any more.

Same as for patch 2, you cannot remove these functions without
impacting the system behavior.

> 
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Jason Cooper <jason@lakedaemon.net>
> Cc: Marc Zyngier <marc.zyngier@arm.com>
> Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
> Cc: Boris BREZILLON <boris.brezillon@free-electrons.com>
> Cc: Ludovic Desroches <ludovic.desroches@atmel.com>
> Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Milo Kim <milo.kim@ti.com>
> ---
>  drivers/irqchip/irq-atmel-aic-common.c | 45 ----------------------------------
>  drivers/irqchip/irq-atmel-aic-common.h |  4 ---
>  drivers/irqchip/irq-atmel-aic.c        | 22 -----------------
>  3 files changed, 71 deletions(-)
> 
> diff --git a/drivers/irqchip/irq-atmel-aic-common.c b/drivers/irqchip/irq-atmel-aic-common.c
> index f8261be..ef2c619 100644
> --- a/drivers/irqchip/irq-atmel-aic-common.c
> +++ b/drivers/irqchip/irq-atmel-aic-common.c
> @@ -139,51 +139,6 @@ static void __init aic_common_ext_irq_of_init(struct irq_domain *domain)
>  	}
>  }
>  
> -#define AT91_RTT_MR		0x00			/* Real-time Mode Register */
> -#define AT91_RTT_ALMIEN		(1 << 16)		/* Alarm Interrupt Enable */
> -#define AT91_RTT_RTTINCIEN	(1 << 17)		/* Real Time Timer Increment Interrupt Enable */
> -
> -void __init aic_common_rtt_irq_fixup(struct device_node *root)
> -{
> -	struct device_node *np;
> -	void __iomem *regs;
> -
> -	/*
> -	 * The at91sam9263 SoC has 2 instances of the RTT block, hence we
> -	 * iterate over the DT to find each occurrence.
> -	 */
> -	for_each_compatible_node(np, NULL, "atmel,at91sam9260-rtt") {
> -		regs = of_iomap(np, 0);
> -		if (!regs)
> -			continue;
> -
> -		writel(readl(regs + AT91_RTT_MR) &
> -		       ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN),
> -		       regs + AT91_RTT_MR);
> -
> -		iounmap(regs);
> -	}
> -}
> -
> -void __init aic_common_irq_fixup(const struct of_device_id *matches)
> -{
> -	struct device_node *root = of_find_node_by_path("/");
> -	const struct of_device_id *match;
> -
> -	if (!root)
> -		return;
> -
> -	match = of_match_node(matches, root);
> -	of_node_put(root);
> -
> -	if (match) {
> -		void (*fixup)(struct device_node *) = match->data;
> -		fixup(root);
> -	}
> -
> -	of_node_put(root);
> -}
> -
>  struct irq_domain *__init aic_common_of_init(struct device_node *node,
>  					     const struct irq_domain_ops *ops,
>  					     const char *name, int nirqs)
> diff --git a/drivers/irqchip/irq-atmel-aic-common.h b/drivers/irqchip/irq-atmel-aic-common.h
> index 9027f15..c178557 100644
> --- a/drivers/irqchip/irq-atmel-aic-common.h
> +++ b/drivers/irqchip/irq-atmel-aic-common.h
> @@ -32,8 +32,4 @@ struct irq_domain *__init aic_common_of_init(struct device_node *node,
>  					     const struct irq_domain_ops *ops,
>  					     const char *name, int nirqs);
>  
> -void __init aic_common_rtt_irq_fixup(struct device_node *root);
> -
> -void __init aic_common_irq_fixup(const struct of_device_id *matches);
> -
>  #endif /* __IRQ_ATMEL_AIC_COMMON_H */
> diff --git a/drivers/irqchip/irq-atmel-aic.c b/drivers/irqchip/irq-atmel-aic.c
> index 4c60224..6fcd680 100644
> --- a/drivers/irqchip/irq-atmel-aic.c
> +++ b/drivers/irqchip/irq-atmel-aic.c
> @@ -209,26 +209,6 @@ static const struct irq_domain_ops aic_irq_ops = {
>  	.xlate	= aic_irq_domain_xlate,
>  };
>  
> -static void __init at91sam9260_aic_irq_fixup(struct device_node *root)
> -{
> -	aic_common_rtt_irq_fixup(root);
> -}
> -
> -static void __init at91sam9g45_aic_irq_fixup(struct device_node *root)
> -{
> -	aic_common_rtt_irq_fixup(root);
> -}
> -
> -static const struct of_device_id aic_irq_fixups[] __initconst = {
> -	{ .compatible = "atmel,at91sam9g45", .data = at91sam9g45_aic_irq_fixup },
> -	{ .compatible = "atmel,at91sam9rl", .data = at91sam9g45_aic_irq_fixup },
> -	{ .compatible = "atmel,at91sam9260", .data = at91sam9260_aic_irq_fixup },
> -	{ .compatible = "atmel,at91sam9261", .data = at91sam9260_aic_irq_fixup },
> -	{ .compatible = "atmel,at91sam9263", .data = at91sam9260_aic_irq_fixup },
> -	{ .compatible = "atmel,at91sam9g20", .data = at91sam9260_aic_irq_fixup },
> -	{ /* sentinel */ },
> -};
> -
>  static int __init aic_of_init(struct device_node *node,
>  			      struct device_node *parent)
>  {
> @@ -243,8 +223,6 @@ static int __init aic_of_init(struct device_node *node,
>  	if (IS_ERR(domain))
>  		return PTR_ERR(domain);
>  
> -	aic_common_irq_fixup(aic_irq_fixups);
> -
>  	aic_domain = domain;
>  	gc = irq_get_domain_generic_chip(domain, 0);
>  



-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com