Message-ID: <543BD71F.7020000@gmail.com>
Date:	Mon, 13 Oct 2014 15:43:59 +0200
From:	Matthias Brugger <matthias.bgg@...il.com>
To:	"Joe.C" <yingjoe.chen@...iatek.com>, arm@...nel.org,
	Rob Herring <robh+dt@...nel.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Jiang Liu <jiang.liu@...ux.intel.com>,
	Marc Zyngier <marc.zyngier@....com>,
	Mark Rutland <mark.rutland@....com>
CC:	linux-arm-kernel@...ts.infradead.org, srv_heupstream@...iatek.com,
	yingjoe.chen@...il.com, hc.yen@...iatek.com,
	eddie.huang@...iatek.com, nathan.chung@...iatek.com,
	yh.chen@...iatek.com, Sascha Hauer <kernel@...gutronix.de>,
	Olof Johansson <olof@...om.net>, Arnd Bergmann <arnd@...db.de>,
	Pawel Moll <pawel.moll@....com>,
	Russell King <linux@....linux.org.uk>,
	Jason Cooper <jason@...edaemon.net>,
	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	Santosh Shilimkar <santosh.shilimkar@...com>,
	Matt Porter <mporter@...aro.org>,
	Marc Carino <marc.ceeeee@...il.com>,
	Florian Fainelli <f.fainelli@...il.com>,
	Sricharan R <r.sricharan@...com>,
	Grant Likely <grant.likely@...aro.org>,
	devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 4/7] ARM: mediatek: Add sysirq interrupt polarity support



On 09/10/14 16:29, Joe.C wrote:
> From: "Joe.C" <yingjoe.chen@...iatek.com>
> 
> Mediatek SoCs have interrupt polarity in sysirq which allows
> to swap the polarity for given interrupts. Add this support
> using hierarchy irq domain.
> 
> Signed-off-by: Joe.C <yingjoe.chen@...iatek.com>
> ---
>  arch/arm/mach-mediatek/Kconfig      |   1 +
>  drivers/irqchip/Makefile            |   1 +
>  drivers/irqchip/irq-mt65xx-sysirq.c | 170 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 172 insertions(+)
>  create mode 100644 drivers/irqchip/irq-mt65xx-sysirq.c
> 
> diff --git a/arch/arm/mach-mediatek/Kconfig b/arch/arm/mach-mediatek/Kconfig
> index 2c043a2..7093859 100644
> --- a/arch/arm/mach-mediatek/Kconfig
> +++ b/arch/arm/mach-mediatek/Kconfig
> @@ -2,5 +2,6 @@ config ARCH_MEDIATEK
>  	bool "Mediatek MT6589 SoC" if ARCH_MULTI_V7
>  	select ARM_GIC
>  	select MTK_TIMER
> +	select IRQ_DOMAIN_HIERARCHY
>  	help
>  	  Support for Mediatek Cortex-A7 Quad-Core-SoC MT6589.
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index 73052ba..809c9d5 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -34,3 +34,4 @@ obj-$(CONFIG_XTENSA)			+= irq-xtensa-pic.o
>  obj-$(CONFIG_XTENSA_MX)			+= irq-xtensa-mx.o
>  obj-$(CONFIG_IRQ_CROSSBAR)		+= irq-crossbar.o
>  obj-$(CONFIG_BRCMSTB_L2_IRQ)		+= irq-brcmstb-l2.o
> +obj-$(CONFIG_ARCH_MEDIATEK)		+= irq-mt65xx-sysirq.o
> diff --git a/drivers/irqchip/irq-mt65xx-sysirq.c b/drivers/irqchip/irq-mt65xx-sysirq.c
> new file mode 100644
> index 0000000..9e0eee5
> --- /dev/null
> +++ b/drivers/irqchip/irq-mt65xx-sysirq.c
> @@ -0,0 +1,170 @@
> +/*
> + * Copyright (c) 2014 MediaTek Inc.
> + * Author: Joe.C <yingjoe.chen@...iatek.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/irq.h>
> +#include <linux/irqdomain.h>
> +#include <linux/of.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_address.h>
> +#include <linux/io.h>
> +#include <linux/slab.h>
> +#include <linux/spinlock.h>
> +
> +#include "irqchip.h"
> +
> +#define MT6577_SYS_INTPOL_NUM	(224)
> +
> +struct mt_sysirq_chip_data {
> +	spinlock_t lock;
> +	void __iomem *intpol_base;
> +};
> +
> +
> +static int mt_sysirq_set_type(struct irq_data *data, unsigned int type)

Are the mt_sysirq_ prefixed functions special to mt65xx processors? In
this case you should prefix them mt65xx_sysirq_
If not, please rename to mtk_sysirq_ to have a consistency in the kernel.

> +{
> +	irq_hw_number_t hwirq = data->hwirq;
> +	struct mt_sysirq_chip_data *chip_data = data->chip_data;
> +	u32 offset, reg_index, value;
> +	unsigned long flags;
> +	int ret;
> +
> +	offset = hwirq & 0x1f;
> +	reg_index = hwirq >> 5;
> +
> +	spin_lock_irqsave(&chip_data->lock, flags);
> +	value = readl_relaxed(chip_data->intpol_base + reg_index * 4);
> +	if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_EDGE_FALLING) {
> +		if (type == IRQ_TYPE_LEVEL_LOW)
> +			type = IRQ_TYPE_LEVEL_HIGH;
> +		else
> +			type = IRQ_TYPE_EDGE_RISING;
> +		value |= (1 << offset);
> +	} else
> +		value &= ~(1 << offset);
> +	writel(value, chip_data->intpol_base + reg_index * 4);
> +
> +	data = data->parent_data;
> +	ret = data->chip->irq_set_type(data, type);
> +	spin_unlock_irqrestore(&chip_data->lock, flags);
> +	return ret;
> +}
> +
> +static struct irq_chip mt_sysirq_chip = {
> +	.name			= "MT_SYSIRQ",
> +	.irq_mask		= irq_chip_mask_parent,
> +	.irq_unmask		= irq_chip_unmask_parent,
> +	.irq_eoi		= irq_chip_eoi_parent,
> +	.irq_set_type		= mt_sysirq_set_type,
> +	.irq_retrigger		= irq_chip_retrigger_hierarchy,
> +	.irq_set_affinity	= irq_chip_set_affinity_parent,
> +};
> +
> +static int mt_sysirq_domain_alloc(struct irq_domain *domain, unsigned int virq,
> +				unsigned int nr_irqs, void *arg)

Same here.

> +{
> +	int i, ret;
> +	irq_hw_number_t hwirq;
> +	struct of_phandle_args *irq_data = arg;
> +	unsigned int type;
> +
> +	if (irq_data->args_count != 3)
> +		return -EINVAL;
> +
> +	hwirq = irq_data->args[1];
> +	if (irq_find_mapping(domain, hwirq) > 0)
> +		return -EEXIST;
> +
> +	for (i = 0; i < nr_irqs; i++)
> +		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
> +					&mt_sysirq_chip, domain->host_data);
> +
> +	ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);
> +	if (ret < 0)
> +		return ret;
> +
> +	type = irq_data->args[2] & IRQ_TYPE_SENSE_MASK;
> +
> +	/* Set type if specified and different than the current one */
> +	if (type != IRQ_TYPE_NONE &&
> +	    type != irq_get_trigger_type(virq))
> +		irq_set_irq_type(virq, type);
> +
> +	return 0;
> +}
> +
> +static void mt_sysirq_domain_free(struct irq_domain *domain, unsigned int virq,
> +				unsigned int nr_irqs)

Same here.

> +{
> +	int i;
> +
> +	for (i = 0; i < nr_irqs; i++) {
> +		irq_set_handler(virq + i, NULL);
> +		irq_domain_set_hwirq_and_chip(domain, virq + i, 0, NULL, NULL);
> +	}
> +	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
> +}
> +
> +static struct irq_domain_ops sysirq_domain_ops = {
> +	.alloc = mt_sysirq_domain_alloc,
> +	.free = mt_sysirq_domain_free,
> +};
> +
> +static int __init mtk_sysirq_of_init(struct device_node *node,
> +				   struct device_node *parent)
> +{
> +	struct device_node *parent_node;
> +	struct irq_domain *domain, *domain_parent = NULL;
> +	struct mt_sysirq_chip_data *chip_data;
> +	int ret = 0;
> +
> +	parent_node = of_irq_find_parent(node);
> +	if (parent_node) {
> +		domain_parent = irq_find_host(parent_node);
> +		of_node_put(parent_node);
> +	}
> +
> +	if (!domain_parent) {
> +		pr_err("mtk_sysirq: interrupt-parent not found\n");
> +		return -EINVAL;
> +	}
> +
> +	chip_data = kzalloc(sizeof(*chip_data), GFP_KERNEL);
> +	if (!chip_data)
> +		return -ENOMEM;
> +
> +	chip_data->intpol_base = of_io_request_and_map(node, 0, "intpol");
> +	if (!chip_data->intpol_base) {
> +		pr_err("mtk_sysirq: unable to map sysirq register\n");
> +		ret = -ENOMEM;
> +		goto out_free;
> +	}
> +
> +	domain = irq_domain_add_linear(node, MT6577_SYS_INTPOL_NUM,
> +				&sysirq_domain_ops, chip_data);
> +	if (!domain) {
> +		ret = -ENOMEM;
> +		goto out_unmap;
> +	}
> +	domain->parent = domain_parent;
> +	spin_lock_init(&chip_data->lock);
> +
> +	return 0;
> +
> +out_unmap:
> +	iounmap(chip_data->intpol_base);
> +out_free:
> +	kfree(chip_data);
> +	return ret;
> +}
> +IRQCHIP_DECLARE(mtk_sysirq, "mediatek,mt6577-sysirq", mtk_sysirq_of_init);

If this is compatible to all mt65xx from mt6577 upwards, we should
rename the file to irq-mt6577-sysirq.c to have consistency in the naming.

> 
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