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Commit 8cb17b5e authored by Vladimir Zapolskiy's avatar Vladimir Zapolskiy Committed by Marc Zyngier
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irqchip: Add LPC32xx interrupt controller driver 



The change adds improved support of NXP LPC32xx MIC, SIC1 and SIC2
interrupt controllers.

This is a list of new features in comparison to the legacy driver:
* irq types are taken from device tree settings, no more need to
  hardcode them,
* old driver is based on irq_domain_add_legacy, which causes problems
  with handling MIC hardware interrupt 0 produced by SIC1,
* there is one driver for MIC, SIC1 and SIC2, no more need to handle
  them separately, e.g. have two separate handlers for SIC1 and SIC2,
* the driver does not have any dependencies on hardcoded register
  offsets,
* the driver is much simpler for maintenance,
* SPARSE_IRQS option is supported.

Legacy LPC32xx interrupt controller driver was broken since commit
76ba59f8 ("genirq: Add irq_domain-aware core IRQ handler"), which
requires a private interrupt handler, otherwise any SIC1 generated
interrupt (mapped to MIC hwirq 0) breaks the kernel with the message
"unexpected IRQ trap at vector 00".

The change disables compilation of a legacy driver found at
arch/arm/mach-lpc32xx/irq.c, the file will be removed in a separate
commit.

Fixes: 76ba59f8 ("genirq: Add irq_domain-aware core IRQ handler")
Tested-by: default avatarSylvain Lemieux <slemieux.tyco@gmail.com>
Signed-off-by: default avatarVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent f86c4fbd

arch/arm/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -531,6 +531,8 @@ config ARCH_LPC32XX 
	select COMMON_CLK

	select CPU_ARM926T

	select GENERIC_CLOCKEVENTS

	select MULTI_IRQ_HANDLER

	select SPARSE_IRQ

	select USE_OF

	help

	  Support for the NXP LPC32XX family of processors

arch/arm/mach-lpc32xx/phy3250.c

+0 −1
Original line number Diff line number Diff line
@@ -206,7 +206,6 @@ static const char *const lpc32xx_dt_compat[] __initconst = { 
DT_MACHINE_START(LPC32XX_DT, "LPC32XX SoC (Flattened Device Tree)")

	.atag_offset	= 0x100,

	.map_io		= lpc32xx_map_io,

	.init_irq	= lpc32xx_init_irq,

	.init_machine	= lpc3250_machine_init,

	.dt_compat	= lpc32xx_dt_compat,

MACHINE_END

drivers/irqchip/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ obj-$(CONFIG_ARCH_BCM2835) += irq-bcm2835.o 
obj-$(CONFIG_ARCH_BCM2835)		+= irq-bcm2836.o

obj-$(CONFIG_ARCH_EXYNOS)		+= exynos-combiner.o

obj-$(CONFIG_ARCH_HIP04)		+= irq-hip04.o

obj-$(CONFIG_ARCH_LPC32XX)		+= irq-lpc32xx.o

obj-$(CONFIG_ARCH_MMP)			+= irq-mmp.o

obj-$(CONFIG_IRQ_MXS)			+= irq-mxs.o

obj-$(CONFIG_ARCH_TEGRA)		+= irq-tegra.o

drivers/irqchip/irq-lpc32xx.c

0 → 100644
+238 −0
Original line number Diff line number Diff line 
/*

 * Copyright 2015-2016 Vladimir Zapolskiy <vz@mleia.com>

 *

 * The code contained herein is licensed under the GNU General Public

 * License. You may obtain a copy of the GNU General Public License

 * Version 2 or later at the following locations:

 *

 * http://www.opensource.org/licenses/gpl-license.html

 * http://www.gnu.org/copyleft/gpl.html

 */



#define pr_fmt(fmt) "%s: " fmt, __func__



#include <linux/io.h>

#include <linux/irqchip.h>

#include <linux/irqchip/chained_irq.h>

#include <linux/of_address.h>

#include <linux/of_irq.h>

#include <linux/of_platform.h>

#include <linux/slab.h>

#include <asm/exception.h>



#define LPC32XX_INTC_MASK		0x00

#define LPC32XX_INTC_RAW		0x04

#define LPC32XX_INTC_STAT		0x08

#define LPC32XX_INTC_POL		0x0C

#define LPC32XX_INTC_TYPE		0x10

#define LPC32XX_INTC_FIQ		0x14



#define NR_LPC32XX_IC_IRQS		32



struct lpc32xx_irq_chip {

	void __iomem *base;

	struct irq_domain *domain;

	struct irq_chip chip;

};



static struct lpc32xx_irq_chip *lpc32xx_mic_irqc;



static inline u32 lpc32xx_ic_read(struct lpc32xx_irq_chip *ic, u32 reg)

{

	return readl_relaxed(ic->base + reg);

}



static inline void lpc32xx_ic_write(struct lpc32xx_irq_chip *ic,

				    u32 reg, u32 val)

{

	writel_relaxed(val, ic->base + reg);

}



static void lpc32xx_irq_mask(struct irq_data *d)

{

	struct lpc32xx_irq_chip *ic = irq_data_get_irq_chip_data(d);

	u32 val, mask = BIT(d->hwirq);



	val = lpc32xx_ic_read(ic, LPC32XX_INTC_MASK) & ~mask;

	lpc32xx_ic_write(ic, LPC32XX_INTC_MASK, val);

}



static void lpc32xx_irq_unmask(struct irq_data *d)

{

	struct lpc32xx_irq_chip *ic = irq_data_get_irq_chip_data(d);

	u32 val, mask = BIT(d->hwirq);



	val = lpc32xx_ic_read(ic, LPC32XX_INTC_MASK) | mask;

	lpc32xx_ic_write(ic, LPC32XX_INTC_MASK, val);

}



static void lpc32xx_irq_ack(struct irq_data *d)

{

	struct lpc32xx_irq_chip *ic = irq_data_get_irq_chip_data(d);

	u32 mask = BIT(d->hwirq);



	lpc32xx_ic_write(ic, LPC32XX_INTC_RAW, mask);

}



static int lpc32xx_irq_set_type(struct irq_data *d, unsigned int type)

{

	struct lpc32xx_irq_chip *ic = irq_data_get_irq_chip_data(d);

	u32 val, mask = BIT(d->hwirq);

	bool high, edge;



	switch (type) {

	case IRQ_TYPE_EDGE_RISING:

		edge = true;

		high = true;

		break;

	case IRQ_TYPE_EDGE_FALLING:

		edge = true;

		high = false;

		break;

	case IRQ_TYPE_LEVEL_HIGH:

		edge = false;

		high = true;

		break;

	case IRQ_TYPE_LEVEL_LOW:

		edge = false;

		high = false;

		break;

	default:

		pr_info("unsupported irq type %d\n", type);

		return -EINVAL;

	}



	irqd_set_trigger_type(d, type);



	val = lpc32xx_ic_read(ic, LPC32XX_INTC_POL);

	if (high)

		val |= mask;

	else

		val &= ~mask;

	lpc32xx_ic_write(ic, LPC32XX_INTC_POL, val);



	val = lpc32xx_ic_read(ic, LPC32XX_INTC_TYPE);

	if (edge) {

		val |= mask;

		irq_set_handler_locked(d, handle_edge_irq);

	} else {

		val &= ~mask;

		irq_set_handler_locked(d, handle_level_irq);

	}

	lpc32xx_ic_write(ic, LPC32XX_INTC_TYPE, val);



	return 0;

}



static void __exception_irq_entry lpc32xx_handle_irq(struct pt_regs *regs)

{

	struct lpc32xx_irq_chip *ic = lpc32xx_mic_irqc;

	u32 hwirq = lpc32xx_ic_read(ic, LPC32XX_INTC_STAT), irq;



	while (hwirq) {

		irq = __ffs(hwirq);

		hwirq &= ~BIT(irq);

		handle_domain_irq(lpc32xx_mic_irqc->domain, irq, regs);

	}

}



static void lpc32xx_sic_handler(struct irq_desc *desc)

{

	struct lpc32xx_irq_chip *ic = irq_desc_get_handler_data(desc);

	struct irq_chip *chip = irq_desc_get_chip(desc);

	u32 hwirq = lpc32xx_ic_read(ic, LPC32XX_INTC_STAT), irq;



	chained_irq_enter(chip, desc);



	while (hwirq) {

		irq = __ffs(hwirq);

		hwirq &= ~BIT(irq);

		generic_handle_irq(irq_find_mapping(ic->domain, irq));

	}



	chained_irq_exit(chip, desc);

}



static int lpc32xx_irq_domain_map(struct irq_domain *id, unsigned int virq,

				  irq_hw_number_t hw)

{

	struct lpc32xx_irq_chip *ic = id->host_data;



	irq_set_chip_data(virq, ic);

	irq_set_chip_and_handler(virq, &ic->chip, handle_level_irq);

	irq_set_status_flags(virq, IRQ_LEVEL);

	irq_set_noprobe(virq);



	return 0;

}



static void lpc32xx_irq_domain_unmap(struct irq_domain *id, unsigned int virq)

{

	irq_set_chip_and_handler(virq, NULL, NULL);

}



static const struct irq_domain_ops lpc32xx_irq_domain_ops = {

	.map    = lpc32xx_irq_domain_map,

	.unmap	= lpc32xx_irq_domain_unmap,

	.xlate  = irq_domain_xlate_twocell,

};



static int __init lpc32xx_of_ic_init(struct device_node *node,

				     struct device_node *parent)

{

	struct lpc32xx_irq_chip *irqc;

	bool is_mic = of_device_is_compatible(node, "nxp,lpc3220-mic");

	const __be32 *reg = of_get_property(node, "reg", NULL);

	u32 parent_irq, i, addr = reg ? be32_to_cpu(*reg) : 0;



	irqc = kzalloc(sizeof(*irqc), GFP_KERNEL);

	if (!irqc)

		return -ENOMEM;



	irqc->base = of_iomap(node, 0);

	if (!irqc->base) {

		pr_err("%s: unable to map registers\n", node->full_name);

		kfree(irqc);

		return -EINVAL;

	}



	irqc->chip.irq_ack = lpc32xx_irq_ack;

	irqc->chip.irq_mask = lpc32xx_irq_mask;

	irqc->chip.irq_unmask = lpc32xx_irq_unmask;

	irqc->chip.irq_set_type = lpc32xx_irq_set_type;

	if (is_mic)

		irqc->chip.name = kasprintf(GFP_KERNEL, "%08x.mic", addr);

	else

		irqc->chip.name = kasprintf(GFP_KERNEL, "%08x.sic", addr);



	irqc->domain = irq_domain_add_linear(node, NR_LPC32XX_IC_IRQS,

					     &lpc32xx_irq_domain_ops, irqc);

	if (!irqc->domain) {

		pr_err("unable to add irq domain\n");

		iounmap(irqc->base);

		kfree(irqc->chip.name);

		kfree(irqc);

		return -ENODEV;

	}



	if (is_mic) {

		lpc32xx_mic_irqc = irqc;

		set_handle_irq(lpc32xx_handle_irq);

	} else {

		for (i = 0; i < of_irq_count(node); i++) {

			parent_irq = irq_of_parse_and_map(node, i);

			if (parent_irq)

				irq_set_chained_handler_and_data(parent_irq,

						 lpc32xx_sic_handler, irqc);

		}

	}



	lpc32xx_ic_write(irqc, LPC32XX_INTC_MASK, 0x00);

	lpc32xx_ic_write(irqc, LPC32XX_INTC_POL,  0x00);

	lpc32xx_ic_write(irqc, LPC32XX_INTC_TYPE, 0x00);



	return 0;

}



IRQCHIP_DECLARE(nxp_lpc32xx_mic, "nxp,lpc3220-mic", lpc32xx_of_ic_init);

IRQCHIP_DECLARE(nxp_lpc32xx_sic, "nxp,lpc3220-sic", lpc32xx_of_ic_init);