remarkable-linux/drivers/irqchip/irq-mxs.c
Markus Pargmann b5f83e9b06 ARM: mxs: icoll: Fix interrupts gpio bank 0
The mxs interrupt controller does not support polling for interrupts,
but the driver still does it, which is a relict from
pre-MULTI_IRQ_HANDLER times.

The existing code assumes that 0x7f means no interrupt, but this value
is an actually valid irq number, namely gpio bank 0's irq. This results
in the driver not detecting when irq 0x7f is active which makes the
machine effectively dead lock.

This patch removes the interrupt poll loop and allows usage of gpio0
interrupt without an infinite loop.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
2013-06-03 23:18:15 +08:00

116 lines
3.3 KiB
C

/*
* Copyright (C) 2009-2010 Freescale Semiconductor, Inc. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/stmp_device.h>
#include <asm/exception.h>
#include "irqchip.h"
#define HW_ICOLL_VECTOR 0x0000
#define HW_ICOLL_LEVELACK 0x0010
#define HW_ICOLL_CTRL 0x0020
#define HW_ICOLL_STAT_OFFSET 0x0070
#define HW_ICOLL_INTERRUPTn_SET(n) (0x0124 + (n) * 0x10)
#define HW_ICOLL_INTERRUPTn_CLR(n) (0x0128 + (n) * 0x10)
#define BM_ICOLL_INTERRUPTn_ENABLE 0x00000004
#define BV_ICOLL_LEVELACK_IRQLEVELACK__LEVEL0 0x1
#define ICOLL_NUM_IRQS 128
static void __iomem *icoll_base;
static struct irq_domain *icoll_domain;
static void icoll_ack_irq(struct irq_data *d)
{
/*
* The Interrupt Collector is able to prioritize irqs.
* Currently only level 0 is used. So acking can use
* BV_ICOLL_LEVELACK_IRQLEVELACK__LEVEL0 unconditionally.
*/
__raw_writel(BV_ICOLL_LEVELACK_IRQLEVELACK__LEVEL0,
icoll_base + HW_ICOLL_LEVELACK);
}
static void icoll_mask_irq(struct irq_data *d)
{
__raw_writel(BM_ICOLL_INTERRUPTn_ENABLE,
icoll_base + HW_ICOLL_INTERRUPTn_CLR(d->hwirq));
}
static void icoll_unmask_irq(struct irq_data *d)
{
__raw_writel(BM_ICOLL_INTERRUPTn_ENABLE,
icoll_base + HW_ICOLL_INTERRUPTn_SET(d->hwirq));
}
static struct irq_chip mxs_icoll_chip = {
.irq_ack = icoll_ack_irq,
.irq_mask = icoll_mask_irq,
.irq_unmask = icoll_unmask_irq,
};
asmlinkage void __exception_irq_entry icoll_handle_irq(struct pt_regs *regs)
{
u32 irqnr;
irqnr = __raw_readl(icoll_base + HW_ICOLL_STAT_OFFSET);
__raw_writel(irqnr, icoll_base + HW_ICOLL_VECTOR);
irqnr = irq_find_mapping(icoll_domain, irqnr);
handle_IRQ(irqnr, regs);
}
static int icoll_irq_domain_map(struct irq_domain *d, unsigned int virq,
irq_hw_number_t hw)
{
irq_set_chip_and_handler(virq, &mxs_icoll_chip, handle_level_irq);
set_irq_flags(virq, IRQF_VALID);
return 0;
}
static struct irq_domain_ops icoll_irq_domain_ops = {
.map = icoll_irq_domain_map,
.xlate = irq_domain_xlate_onecell,
};
static void __init icoll_of_init(struct device_node *np,
struct device_node *interrupt_parent)
{
icoll_base = of_iomap(np, 0);
WARN_ON(!icoll_base);
/*
* Interrupt Collector reset, which initializes the priority
* for each irq to level 0.
*/
stmp_reset_block(icoll_base + HW_ICOLL_CTRL);
icoll_domain = irq_domain_add_linear(np, ICOLL_NUM_IRQS,
&icoll_irq_domain_ops, NULL);
WARN_ON(!icoll_domain);
}
IRQCHIP_DECLARE(mxs, "fsl,icoll", icoll_of_init);