linux/drivers/gpio/gpio-mxs.c
Sascha Hauer f08ea3cc94 gpio: mxs: fix duplicate level interrupts
According to the reference manual level interrupts can't be acked
using the IRQSTAT registers. The effect is that when a level interrupt
triggers the following ack is a no-op and the same interrupt triggers
again right after it has been unmasked after running the interrupt
handler.

The reference manual says:

Status bits for pins configured as level sensitive interrupts cannot be
cleared unless either the actual pin is in the non-interrupting state, or
the pin has been disabled as an interrupt source by clearing its bit in
HW_PINCTRL_PIN2IRQ.

To work around the duplicated interrupts we can use the PIN2IRQ
rather than the IRQEN registers to mask the interrupts. This
probably does not work for the edge interrupts, so we have to split up
the irq chip into two chip types, one for the level interrupts and
one for the edge interrupts. We now make use of two different enable
registers, so we have to take care to always enable the right one,
especially during switching of the interrupt type. An easy way
to accomplish this is to use the IRQCHIP_SET_TYPE_MASKED which
makes sure that set_irq_type is called with masked interrupts. With this
the flow to change the irq type is like:

- core masks interrupt (using the current chip type)
- mxs_gpio_set_irq_type() changes chip type if necessary
- mxs_gpio_set_irq_type() unconditionally sets the enable bit in the
  now unused enable register
- core eventually unmasks the interrupt (using the new chip type)

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-10-24 16:33:11 +02:00

396 lines
11 KiB
C

/*
* MXC GPIO support. (c) 2008 Daniel Mack <daniel@caiaq.de>
* Copyright 2008 Juergen Beisert, kernel@pengutronix.de
*
* Based on code from Freescale,
* Copyright (C) 2004-2010 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/err.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/gpio/driver.h>
/* FIXME: for gpio_get_value(), replace this by direct register read */
#include <linux/gpio.h>
#include <linux/module.h>
#define MXS_SET 0x4
#define MXS_CLR 0x8
#define PINCTRL_DOUT(p) ((is_imx23_gpio(p) ? 0x0500 : 0x0700) + (p->id) * 0x10)
#define PINCTRL_DIN(p) ((is_imx23_gpio(p) ? 0x0600 : 0x0900) + (p->id) * 0x10)
#define PINCTRL_DOE(p) ((is_imx23_gpio(p) ? 0x0700 : 0x0b00) + (p->id) * 0x10)
#define PINCTRL_PIN2IRQ(p) ((is_imx23_gpio(p) ? 0x0800 : 0x1000) + (p->id) * 0x10)
#define PINCTRL_IRQEN(p) ((is_imx23_gpio(p) ? 0x0900 : 0x1100) + (p->id) * 0x10)
#define PINCTRL_IRQLEV(p) ((is_imx23_gpio(p) ? 0x0a00 : 0x1200) + (p->id) * 0x10)
#define PINCTRL_IRQPOL(p) ((is_imx23_gpio(p) ? 0x0b00 : 0x1300) + (p->id) * 0x10)
#define PINCTRL_IRQSTAT(p) ((is_imx23_gpio(p) ? 0x0c00 : 0x1400) + (p->id) * 0x10)
#define GPIO_INT_FALL_EDGE 0x0
#define GPIO_INT_LOW_LEV 0x1
#define GPIO_INT_RISE_EDGE 0x2
#define GPIO_INT_HIGH_LEV 0x3
#define GPIO_INT_LEV_MASK (1 << 0)
#define GPIO_INT_POL_MASK (1 << 1)
enum mxs_gpio_id {
IMX23_GPIO,
IMX28_GPIO,
};
struct mxs_gpio_port {
void __iomem *base;
int id;
int irq;
struct irq_domain *domain;
struct gpio_chip gc;
enum mxs_gpio_id devid;
u32 both_edges;
};
static inline int is_imx23_gpio(struct mxs_gpio_port *port)
{
return port->devid == IMX23_GPIO;
}
static inline int is_imx28_gpio(struct mxs_gpio_port *port)
{
return port->devid == IMX28_GPIO;
}
/* Note: This driver assumes 32 GPIOs are handled in one register */
static int mxs_gpio_set_irq_type(struct irq_data *d, unsigned int type)
{
u32 val;
u32 pin_mask = 1 << d->hwirq;
struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
struct irq_chip_type *ct = irq_data_get_chip_type(d);
struct mxs_gpio_port *port = gc->private;
void __iomem *pin_addr;
int edge;
if (!(ct->type & type))
if (irq_setup_alt_chip(d, type))
return -EINVAL;
port->both_edges &= ~pin_mask;
switch (type) {
case IRQ_TYPE_EDGE_BOTH:
val = gpio_get_value(port->gc.base + d->hwirq);
if (val)
edge = GPIO_INT_FALL_EDGE;
else
edge = GPIO_INT_RISE_EDGE;
port->both_edges |= pin_mask;
break;
case IRQ_TYPE_EDGE_RISING:
edge = GPIO_INT_RISE_EDGE;
break;
case IRQ_TYPE_EDGE_FALLING:
edge = GPIO_INT_FALL_EDGE;
break;
case IRQ_TYPE_LEVEL_LOW:
edge = GPIO_INT_LOW_LEV;
break;
case IRQ_TYPE_LEVEL_HIGH:
edge = GPIO_INT_HIGH_LEV;
break;
default:
return -EINVAL;
}
/* set level or edge */
pin_addr = port->base + PINCTRL_IRQLEV(port);
if (edge & GPIO_INT_LEV_MASK) {
writel(pin_mask, pin_addr + MXS_SET);
writel(pin_mask, port->base + PINCTRL_IRQEN(port) + MXS_SET);
} else {
writel(pin_mask, pin_addr + MXS_CLR);
writel(pin_mask, port->base + PINCTRL_PIN2IRQ(port) + MXS_SET);
}
/* set polarity */
pin_addr = port->base + PINCTRL_IRQPOL(port);
if (edge & GPIO_INT_POL_MASK)
writel(pin_mask, pin_addr + MXS_SET);
else
writel(pin_mask, pin_addr + MXS_CLR);
writel(pin_mask,
port->base + PINCTRL_IRQSTAT(port) + MXS_CLR);
return 0;
}
static void mxs_flip_edge(struct mxs_gpio_port *port, u32 gpio)
{
u32 bit, val, edge;
void __iomem *pin_addr;
bit = 1 << gpio;
pin_addr = port->base + PINCTRL_IRQPOL(port);
val = readl(pin_addr);
edge = val & bit;
if (edge)
writel(bit, pin_addr + MXS_CLR);
else
writel(bit, pin_addr + MXS_SET);
}
/* MXS has one interrupt *per* gpio port */
static void mxs_gpio_irq_handler(struct irq_desc *desc)
{
u32 irq_stat;
struct mxs_gpio_port *port = irq_desc_get_handler_data(desc);
desc->irq_data.chip->irq_ack(&desc->irq_data);
irq_stat = readl(port->base + PINCTRL_IRQSTAT(port)) &
readl(port->base + PINCTRL_IRQEN(port));
while (irq_stat != 0) {
int irqoffset = fls(irq_stat) - 1;
if (port->both_edges & (1 << irqoffset))
mxs_flip_edge(port, irqoffset);
generic_handle_irq(irq_find_mapping(port->domain, irqoffset));
irq_stat &= ~(1 << irqoffset);
}
}
/*
* Set interrupt number "irq" in the GPIO as a wake-up source.
* While system is running, all registered GPIO interrupts need to have
* wake-up enabled. When system is suspended, only selected GPIO interrupts
* need to have wake-up enabled.
* @param irq interrupt source number
* @param enable enable as wake-up if equal to non-zero
* @return This function returns 0 on success.
*/
static int mxs_gpio_set_wake_irq(struct irq_data *d, unsigned int enable)
{
struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
struct mxs_gpio_port *port = gc->private;
if (enable)
enable_irq_wake(port->irq);
else
disable_irq_wake(port->irq);
return 0;
}
static int __init mxs_gpio_init_gc(struct mxs_gpio_port *port, int irq_base)
{
struct irq_chip_generic *gc;
struct irq_chip_type *ct;
gc = irq_alloc_generic_chip("gpio-mxs", 2, irq_base,
port->base, handle_level_irq);
if (!gc)
return -ENOMEM;
gc->private = port;
ct = &gc->chip_types[0];
ct->type = IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW;
ct->chip.irq_ack = irq_gc_ack_set_bit;
ct->chip.irq_mask = irq_gc_mask_disable_reg;
ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
ct->chip.irq_set_type = mxs_gpio_set_irq_type;
ct->chip.irq_set_wake = mxs_gpio_set_wake_irq;
ct->chip.flags = IRQCHIP_SET_TYPE_MASKED;
ct->regs.ack = PINCTRL_IRQSTAT(port) + MXS_CLR;
ct->regs.enable = PINCTRL_PIN2IRQ(port) + MXS_SET;
ct->regs.disable = PINCTRL_PIN2IRQ(port) + MXS_CLR;
ct = &gc->chip_types[1];
ct->type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
ct->chip.irq_ack = irq_gc_ack_set_bit;
ct->chip.irq_mask = irq_gc_mask_disable_reg;
ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
ct->chip.irq_set_type = mxs_gpio_set_irq_type;
ct->chip.irq_set_wake = mxs_gpio_set_wake_irq;
ct->chip.flags = IRQCHIP_SET_TYPE_MASKED;
ct->regs.ack = PINCTRL_IRQSTAT(port) + MXS_CLR;
ct->regs.enable = PINCTRL_IRQEN(port) + MXS_SET;
ct->regs.disable = PINCTRL_IRQEN(port) + MXS_CLR;
ct->handler = handle_level_irq;
irq_setup_generic_chip(gc, IRQ_MSK(32), IRQ_GC_INIT_NESTED_LOCK,
IRQ_NOREQUEST, 0);
return 0;
}
static int mxs_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
{
struct mxs_gpio_port *port = gpiochip_get_data(gc);
return irq_find_mapping(port->domain, offset);
}
static int mxs_gpio_get_direction(struct gpio_chip *gc, unsigned offset)
{
struct mxs_gpio_port *port = gpiochip_get_data(gc);
u32 mask = 1 << offset;
u32 dir;
dir = readl(port->base + PINCTRL_DOE(port));
return !(dir & mask);
}
static const struct platform_device_id mxs_gpio_ids[] = {
{
.name = "imx23-gpio",
.driver_data = IMX23_GPIO,
}, {
.name = "imx28-gpio",
.driver_data = IMX28_GPIO,
}, {
/* sentinel */
}
};
MODULE_DEVICE_TABLE(platform, mxs_gpio_ids);
static const struct of_device_id mxs_gpio_dt_ids[] = {
{ .compatible = "fsl,imx23-gpio", .data = (void *) IMX23_GPIO, },
{ .compatible = "fsl,imx28-gpio", .data = (void *) IMX28_GPIO, },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mxs_gpio_dt_ids);
static int mxs_gpio_probe(struct platform_device *pdev)
{
const struct of_device_id *of_id =
of_match_device(mxs_gpio_dt_ids, &pdev->dev);
struct device_node *np = pdev->dev.of_node;
struct device_node *parent;
static void __iomem *base;
struct mxs_gpio_port *port;
int irq_base;
int err;
port = devm_kzalloc(&pdev->dev, sizeof(*port), GFP_KERNEL);
if (!port)
return -ENOMEM;
port->id = of_alias_get_id(np, "gpio");
if (port->id < 0)
return port->id;
port->devid = (enum mxs_gpio_id) of_id->data;
port->irq = platform_get_irq(pdev, 0);
if (port->irq < 0)
return port->irq;
/*
* map memory region only once, as all the gpio ports
* share the same one
*/
if (!base) {
parent = of_get_parent(np);
base = of_iomap(parent, 0);
of_node_put(parent);
if (!base)
return -EADDRNOTAVAIL;
}
port->base = base;
/* initially disable the interrupts */
writel(0, port->base + PINCTRL_PIN2IRQ(port));
writel(0, port->base + PINCTRL_IRQEN(port));
/* clear address has to be used to clear IRQSTAT bits */
writel(~0U, port->base + PINCTRL_IRQSTAT(port) + MXS_CLR);
irq_base = irq_alloc_descs(-1, 0, 32, numa_node_id());
if (irq_base < 0)
return irq_base;
port->domain = irq_domain_add_legacy(np, 32, irq_base, 0,
&irq_domain_simple_ops, NULL);
if (!port->domain) {
err = -ENODEV;
goto out_irqdesc_free;
}
/* gpio-mxs can be a generic irq chip */
err = mxs_gpio_init_gc(port, irq_base);
if (err < 0)
goto out_irqdomain_remove;
/* setup one handler for each entry */
irq_set_chained_handler_and_data(port->irq, mxs_gpio_irq_handler,
port);
err = bgpio_init(&port->gc, &pdev->dev, 4,
port->base + PINCTRL_DIN(port),
port->base + PINCTRL_DOUT(port) + MXS_SET,
port->base + PINCTRL_DOUT(port) + MXS_CLR,
port->base + PINCTRL_DOE(port), NULL, 0);
if (err)
goto out_irqdomain_remove;
port->gc.to_irq = mxs_gpio_to_irq;
port->gc.get_direction = mxs_gpio_get_direction;
port->gc.base = port->id * 32;
err = gpiochip_add_data(&port->gc, port);
if (err)
goto out_irqdomain_remove;
return 0;
out_irqdomain_remove:
irq_domain_remove(port->domain);
out_irqdesc_free:
irq_free_descs(irq_base, 32);
return err;
}
static struct platform_driver mxs_gpio_driver = {
.driver = {
.name = "gpio-mxs",
.of_match_table = mxs_gpio_dt_ids,
},
.probe = mxs_gpio_probe,
.id_table = mxs_gpio_ids,
};
static int __init mxs_gpio_init(void)
{
return platform_driver_register(&mxs_gpio_driver);
}
postcore_initcall(mxs_gpio_init);
MODULE_AUTHOR("Freescale Semiconductor, "
"Daniel Mack <danielncaiaq.de>, "
"Juergen Beisert <kernel@pengutronix.de>");
MODULE_DESCRIPTION("Freescale MXS GPIO");
MODULE_LICENSE("GPL");