Re: RT_PREEMPT problem with cascaded irqchip

Yann.LEPROVOST
2006-05-30T10:32:58Z

Of course, here is the file arch/arm/mach-at91rm9200/gpio.c with my
modified gpio_irq_handler.

/*
* linux/arch/arm/mach-at91rm9200/gpio.c
*
* Copyright (C) 2005 HP Labs
*
* 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.
*/

#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>

#include <asm/io.h>
#include <asm/mach/irq.h>
#include <asm/arch/hardware.h>
#include <asm/arch/gpio.h>

static const u32 pio_controller_offset[4] = {
AT91_PIOA,
AT91_PIOB,
AT91_PIOC,
AT91_PIOD,
};

static inline void __iomem *pin_to_controller(unsigned pin)
{
void __iomem *sys_base = (void __iomem *) AT91_VA_BASE_SYS;

pin -= PIN_BASE;
pin /= 32;
if (likely(pin < BGA_GPIO_BANKS))
return sys_base + pio_controller_offset[pin];

return NULL;
}

static inline unsigned pin_to_mask(unsigned pin)
{
pin -= PIN_BASE;
return 1 << (pin % 32);
}

/*--------------------------------------------------------------------------*/

/* Not all hardware capabilities are exposed through these calls; they
* only encapsulate the most common features and modes. (So if you
* want to change signals in groups, do it directly.)
*
* Bootloaders will usually handle some of the pin multiplexing setup.
* The intent is certainly that by the time Linux is fully booted, all
* pins should have been fully initialized. These setup calls should
* only be used by board setup routines, or possibly in driver probe().
*
* For bootloaders doing all that setup, these calls could be inlined
* as NOPs so Linux won't duplicate any setup code
*/

/*
* mux the pin to the "A" internal peripheral role.
*/
int __init_or_module at91_set_A_periph(unsigned pin, int use_pullup)
{
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);

if (!pio)
return -EINVAL;

__raw_writel(mask, pio + PIO_IDR);
__raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR));
__raw_writel(mask, pio + PIO_ASR);
__raw_writel(mask, pio + PIO_PDR);
return 0;
}
EXPORT_SYMBOL(at91_set_A_periph);

/*
* mux the pin to the "B" internal peripheral role.
*/
int __init_or_module at91_set_B_periph(unsigned pin, int use_pullup)
{
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);

if (!pio)
return -EINVAL;

__raw_writel(mask, pio + PIO_IDR);
__raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR));
__raw_writel(mask, pio + PIO_BSR);
__raw_writel(mask, pio + PIO_PDR);
return 0;
}
EXPORT_SYMBOL(at91_set_B_periph);

/*
* mux the pin to the gpio controller (instead of "A" or "B" peripheral),
and
* configure it for an input.
*/
int __init_or_module at91_set_gpio_input(unsigned pin, int use_pullup)
{
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);

if (!pio)
return -EINVAL;

__raw_writel(mask, pio + PIO_IDR);
__raw_writel(mask, pio + (use_pullup ? PIO_PUER : PIO_PUDR));
__raw_writel(mask, pio + PIO_ODR);
__raw_writel(mask, pio + PIO_PER);
return 0;
}
EXPORT_SYMBOL(at91_set_gpio_input);

/*
* mux the pin to the gpio controller (instead of "A" or "B" peripheral),
* and configure it for an output.
*/
int __init_or_module at91_set_gpio_output(unsigned pin, int value)
{
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);

if (!pio)
return -EINVAL;

__raw_writel(mask, pio + PIO_IDR);
__raw_writel(mask, pio + PIO_PUDR);
__raw_writel(mask, pio + (value ? PIO_SODR : PIO_CODR));
__raw_writel(mask, pio + PIO_OER);
__raw_writel(mask, pio + PIO_PER);
return 0;
}
EXPORT_SYMBOL(at91_set_gpio_output);

/*
* enable/disable the glitch filter; mostly used with IRQ handling.
*/
int __init_or_module at91_set_deglitch(unsigned pin, int is_on)
{
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);

if (!pio)
return -EINVAL;
__raw_writel(mask, pio + (is_on ? PIO_IFER : PIO_IFDR));
return 0;
}
EXPORT_SYMBOL(at91_set_deglitch);

/*
* enable/disable the multi-driver; This is only valid for output and
* allows the output pin to run as an open collector output.
*/
int __init_or_module at91_set_multi_drive(unsigned pin, int is_on)
{
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);

if (!pio)
return -EINVAL;

__raw_writel(mask, pio + (is_on ? PIO_MDER : PIO_MDDR));
return 0;
}
EXPORT_SYMBOL(at91_set_multi_drive);

/*--------------------------------------------------------------------------*/

/*
* assuming the pin is muxed as a gpio output, set its value.
*/
int at91_set_gpio_value(unsigned pin, int value)
{
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);

if (!pio)
return -EINVAL;
__raw_writel(mask, pio + (value ? PIO_SODR : PIO_CODR));
return 0;
}
EXPORT_SYMBOL(at91_set_gpio_value);

/*
* read the pin's value (works even if it's not muxed as a gpio).
*/
int at91_get_gpio_value(unsigned pin)
{
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);
u32 pdsr;

if (!pio)
return -EINVAL;
pdsr = __raw_readl(pio + PIO_PDSR);
return (pdsr & mask) != 0;
}
EXPORT_SYMBOL(at91_get_gpio_value);

/*--------------------------------------------------------------------------*/

/* Several AIC controller irqs are dispatched through this GPIO handler.
* To use any AT91_PIN_* as an externally triggered IRQ, first call
* at91_set_gpio_input() then maybe enable its glitch filter.
* Then just request_irq() with the pin ID; it works like any ARM IRQ
* handler, though it always triggers on rising and falling edges.
*
* Alternatively, certain pins may be used directly as IRQ0..IRQ6 after
* configuring them with at91_set_a_periph() or at91_set_b_periph().
* IRQ0..IRQ6 should be configurable, e.g. level vs edge triggering.
*/

static void gpio_irq_mask(unsigned pin)
{
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);

if (pio)
__raw_writel(mask, pio + PIO_IDR);
}

static void gpio_irq_unmask(unsigned pin)
{
void __iomem *pio = pin_to_controller(pin);
unsigned mask = pin_to_mask(pin);

if (pio)
__raw_writel(mask, pio + PIO_IER);
}

static int gpio_irq_type(unsigned pin, unsigned type)
{
return (type == IRQT_BOTHEDGE) ? 0 : -EINVAL;
}

static struct irqchip gpio_irqchip = {
.mask = gpio_irq_mask,
.unmask = gpio_irq_unmask,
.set_type = gpio_irq_type,
};

static void gpio_irq_handler(unsigned irq, struct irqdesc *desc, struct
pt_regs *regs)
{
desc->chip->mask(irq);
desc->chip->unmask(irq);
}

static DEFINE_IRQ_CHAINED_TYPE(gpio_irq_handler);

/* call this from board-specific init_irq */
void __init at91_gpio_irq_setup(unsigned banks)
{
unsigned pioc, pin, id;

if (banks > 4)
banks = 4;
for (pioc = 0, pin = PIN_BASE, id = AT91_ID_PIOA;
pioc < banks;
pioc++, id++) {
void __iomem *controller;
unsigned i;

controller = (void __iomem *) AT91_VA_BASE_SYS +
pio_controller_offset[pioc];
__raw_writel(~0, controller + PIO_IDR);

set_irq_data(id, (void *) pin);
set_irq_chipdata(id, (void __force *) controller);

for (i = 0; i < 32; i++, pin++) {
set_irq_chip(pin, &gpio_irqchip);
printk(KERN_ERR "GPIO SET_IRQ_CHIP\n");
set_irq_handler(pin, do_simple_IRQ);
set_irq_flags(pin, IRQF_VALID);
}

set_irq_chained_handler(id, gpio_irq_handler);

/* enable the PIO peripheral clock */
at91_sys_write(AT91_PMC_PCER, 1 << id);
}
pr_info("AT91: %d gpio irqs in %d banks\n", pin - PIN_BASE, banks);
}

Thomas Gleixner
<tglx@linutronix.
de> To
Sent by: Yann.LEPROVOST@wavecom.fr
linux-kernel-owne cc
r@vger.kernel.org Sven-Thorsten Dietrich
<sven@mvista.com>, Daniel Walker
<dwalker@mvista.com>,
30/05/2006 12:27 linux-kernel@vger.kernel.org,
linux-kernel-owner@vger.kernel.org,
Ingo Molnar <mingo@elte.hu>, Steven
Please respond to Rostedt <rostedt@goodmis.org>,
tglx@linutronix.d Esben Nielsen <simlo@phys.au.dk>
e Subject
Re: RT_PREEMPT problem with
cascaded irqchip

On Tue, 2006-05-30 at 12:00 +0200, Yann.LEPROVOST@wavecom.fr wrote:
> Hi folks,
>
> However, when calling desc->chip->mask, the function at91rm9200_mask_irq
is
> called instead of gpio_mask_irq !

Well, propably the chip setting of the gpio interrupts is not correct.
Can you show me the code please ?

tglx

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/