linux/drivers/gpio/gpio-em.c
Bartosz Golaszewski 19ec11a223 gpio: em: remove the gpiochip before removing the irq domain
In commit 8764c4ca50 ("gpio: em: use the managed version of
gpiochip_add_data()") we implicitly altered the ordering of resource
freeing: since gpiochip_remove() calls gpiochip_irqchip_remove()
internally, we now can potentially use the irq_domain after it was
destroyed in the remove() callback (as devm resources are freed after
remove() has returned).

Use devm_add_action_or_reset() to keep the ordering right and entirely
kill the remove() callback in the driver.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Fixes: 8764c4ca50 ("gpio: em: use the managed version of gpiochip_add_data()")
Cc: stable@vger.kernel.org
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
2019-07-15 11:52:42 +02:00

398 lines
9.7 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Emma Mobile GPIO Support - GIO
*
* Copyright (C) 2012 Magnus Damm
*/
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/gpio/driver.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/pinctrl/consumer.h>
struct em_gio_priv {
void __iomem *base0;
void __iomem *base1;
spinlock_t sense_lock;
struct platform_device *pdev;
struct gpio_chip gpio_chip;
struct irq_chip irq_chip;
struct irq_domain *irq_domain;
};
#define GIO_E1 0x00
#define GIO_E0 0x04
#define GIO_EM 0x04
#define GIO_OL 0x08
#define GIO_OH 0x0c
#define GIO_I 0x10
#define GIO_IIA 0x14
#define GIO_IEN 0x18
#define GIO_IDS 0x1c
#define GIO_IIM 0x1c
#define GIO_RAW 0x20
#define GIO_MST 0x24
#define GIO_IIR 0x28
#define GIO_IDT0 0x40
#define GIO_IDT1 0x44
#define GIO_IDT2 0x48
#define GIO_IDT3 0x4c
#define GIO_RAWBL 0x50
#define GIO_RAWBH 0x54
#define GIO_IRBL 0x58
#define GIO_IRBH 0x5c
#define GIO_IDT(n) (GIO_IDT0 + ((n) * 4))
static inline unsigned long em_gio_read(struct em_gio_priv *p, int offs)
{
if (offs < GIO_IDT0)
return ioread32(p->base0 + offs);
else
return ioread32(p->base1 + (offs - GIO_IDT0));
}
static inline void em_gio_write(struct em_gio_priv *p, int offs,
unsigned long value)
{
if (offs < GIO_IDT0)
iowrite32(value, p->base0 + offs);
else
iowrite32(value, p->base1 + (offs - GIO_IDT0));
}
static void em_gio_irq_disable(struct irq_data *d)
{
struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
em_gio_write(p, GIO_IDS, BIT(irqd_to_hwirq(d)));
}
static void em_gio_irq_enable(struct irq_data *d)
{
struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
em_gio_write(p, GIO_IEN, BIT(irqd_to_hwirq(d)));
}
static int em_gio_irq_reqres(struct irq_data *d)
{
struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
int ret;
ret = gpiochip_lock_as_irq(&p->gpio_chip, irqd_to_hwirq(d));
if (ret) {
dev_err(p->gpio_chip.parent,
"unable to lock HW IRQ %lu for IRQ\n",
irqd_to_hwirq(d));
return ret;
}
return 0;
}
static void em_gio_irq_relres(struct irq_data *d)
{
struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
gpiochip_unlock_as_irq(&p->gpio_chip, irqd_to_hwirq(d));
}
#define GIO_ASYNC(x) (x + 8)
static unsigned char em_gio_sense_table[IRQ_TYPE_SENSE_MASK + 1] = {
[IRQ_TYPE_EDGE_RISING] = GIO_ASYNC(0x00),
[IRQ_TYPE_EDGE_FALLING] = GIO_ASYNC(0x01),
[IRQ_TYPE_LEVEL_HIGH] = GIO_ASYNC(0x02),
[IRQ_TYPE_LEVEL_LOW] = GIO_ASYNC(0x03),
[IRQ_TYPE_EDGE_BOTH] = GIO_ASYNC(0x04),
};
static int em_gio_irq_set_type(struct irq_data *d, unsigned int type)
{
unsigned char value = em_gio_sense_table[type & IRQ_TYPE_SENSE_MASK];
struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
unsigned int reg, offset, shift;
unsigned long flags;
unsigned long tmp;
if (!value)
return -EINVAL;
offset = irqd_to_hwirq(d);
pr_debug("gio: sense irq = %d, mode = %d\n", offset, value);
/* 8 x 4 bit fields in 4 IDT registers */
reg = GIO_IDT(offset >> 3);
shift = (offset & 0x07) << 4;
spin_lock_irqsave(&p->sense_lock, flags);
/* disable the interrupt in IIA */
tmp = em_gio_read(p, GIO_IIA);
tmp &= ~BIT(offset);
em_gio_write(p, GIO_IIA, tmp);
/* change the sense setting in IDT */
tmp = em_gio_read(p, reg);
tmp &= ~(0xf << shift);
tmp |= value << shift;
em_gio_write(p, reg, tmp);
/* clear pending interrupts */
em_gio_write(p, GIO_IIR, BIT(offset));
/* enable the interrupt in IIA */
tmp = em_gio_read(p, GIO_IIA);
tmp |= BIT(offset);
em_gio_write(p, GIO_IIA, tmp);
spin_unlock_irqrestore(&p->sense_lock, flags);
return 0;
}
static irqreturn_t em_gio_irq_handler(int irq, void *dev_id)
{
struct em_gio_priv *p = dev_id;
unsigned long pending;
unsigned int offset, irqs_handled = 0;
while ((pending = em_gio_read(p, GIO_MST))) {
offset = __ffs(pending);
em_gio_write(p, GIO_IIR, BIT(offset));
generic_handle_irq(irq_find_mapping(p->irq_domain, offset));
irqs_handled++;
}
return irqs_handled ? IRQ_HANDLED : IRQ_NONE;
}
static inline struct em_gio_priv *gpio_to_priv(struct gpio_chip *chip)
{
return gpiochip_get_data(chip);
}
static int em_gio_direction_input(struct gpio_chip *chip, unsigned offset)
{
em_gio_write(gpio_to_priv(chip), GIO_E0, BIT(offset));
return 0;
}
static int em_gio_get(struct gpio_chip *chip, unsigned offset)
{
return !!(em_gio_read(gpio_to_priv(chip), GIO_I) & BIT(offset));
}
static void __em_gio_set(struct gpio_chip *chip, unsigned int reg,
unsigned shift, int value)
{
/* upper 16 bits contains mask and lower 16 actual value */
em_gio_write(gpio_to_priv(chip), reg,
(BIT(shift + 16)) | (value << shift));
}
static void em_gio_set(struct gpio_chip *chip, unsigned offset, int value)
{
/* output is split into two registers */
if (offset < 16)
__em_gio_set(chip, GIO_OL, offset, value);
else
__em_gio_set(chip, GIO_OH, offset - 16, value);
}
static int em_gio_direction_output(struct gpio_chip *chip, unsigned offset,
int value)
{
/* write GPIO value to output before selecting output mode of pin */
em_gio_set(chip, offset, value);
em_gio_write(gpio_to_priv(chip), GIO_E1, BIT(offset));
return 0;
}
static int em_gio_to_irq(struct gpio_chip *chip, unsigned offset)
{
return irq_create_mapping(gpio_to_priv(chip)->irq_domain, offset);
}
static int em_gio_request(struct gpio_chip *chip, unsigned offset)
{
return pinctrl_gpio_request(chip->base + offset);
}
static void em_gio_free(struct gpio_chip *chip, unsigned offset)
{
pinctrl_gpio_free(chip->base + offset);
/* Set the GPIO as an input to ensure that the next GPIO request won't
* drive the GPIO pin as an output.
*/
em_gio_direction_input(chip, offset);
}
static int em_gio_irq_domain_map(struct irq_domain *h, unsigned int irq,
irq_hw_number_t hwirq)
{
struct em_gio_priv *p = h->host_data;
pr_debug("gio: map hw irq = %d, irq = %d\n", (int)hwirq, irq);
irq_set_chip_data(irq, h->host_data);
irq_set_chip_and_handler(irq, &p->irq_chip, handle_level_irq);
return 0;
}
static const struct irq_domain_ops em_gio_irq_domain_ops = {
.map = em_gio_irq_domain_map,
.xlate = irq_domain_xlate_twocell,
};
static void em_gio_irq_domain_remove(void *data)
{
struct irq_domain *domain = data;
irq_domain_remove(domain);
}
static int em_gio_probe(struct platform_device *pdev)
{
struct em_gio_priv *p;
struct resource *io[2], *irq[2];
struct gpio_chip *gpio_chip;
struct irq_chip *irq_chip;
const char *name = dev_name(&pdev->dev);
unsigned int ngpios;
int ret;
p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
if (!p)
return -ENOMEM;
p->pdev = pdev;
platform_set_drvdata(pdev, p);
spin_lock_init(&p->sense_lock);
io[0] = platform_get_resource(pdev, IORESOURCE_MEM, 0);
io[1] = platform_get_resource(pdev, IORESOURCE_MEM, 1);
irq[0] = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
irq[1] = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
if (!io[0] || !io[1] || !irq[0] || !irq[1]) {
dev_err(&pdev->dev, "missing IRQ or IOMEM\n");
return -EINVAL;
}
p->base0 = devm_ioremap_nocache(&pdev->dev, io[0]->start,
resource_size(io[0]));
if (!p->base0)
return -ENOMEM;
p->base1 = devm_ioremap_nocache(&pdev->dev, io[1]->start,
resource_size(io[1]));
if (!p->base1)
return -ENOMEM;
if (of_property_read_u32(pdev->dev.of_node, "ngpios", &ngpios)) {
dev_err(&pdev->dev, "Missing ngpios OF property\n");
return -EINVAL;
}
gpio_chip = &p->gpio_chip;
gpio_chip->of_node = pdev->dev.of_node;
gpio_chip->direction_input = em_gio_direction_input;
gpio_chip->get = em_gio_get;
gpio_chip->direction_output = em_gio_direction_output;
gpio_chip->set = em_gio_set;
gpio_chip->to_irq = em_gio_to_irq;
gpio_chip->request = em_gio_request;
gpio_chip->free = em_gio_free;
gpio_chip->label = name;
gpio_chip->parent = &pdev->dev;
gpio_chip->owner = THIS_MODULE;
gpio_chip->base = -1;
gpio_chip->ngpio = ngpios;
irq_chip = &p->irq_chip;
irq_chip->name = name;
irq_chip->irq_mask = em_gio_irq_disable;
irq_chip->irq_unmask = em_gio_irq_enable;
irq_chip->irq_set_type = em_gio_irq_set_type;
irq_chip->irq_request_resources = em_gio_irq_reqres;
irq_chip->irq_release_resources = em_gio_irq_relres;
irq_chip->flags = IRQCHIP_SKIP_SET_WAKE | IRQCHIP_MASK_ON_SUSPEND;
p->irq_domain = irq_domain_add_simple(pdev->dev.of_node, ngpios, 0,
&em_gio_irq_domain_ops, p);
if (!p->irq_domain) {
dev_err(&pdev->dev, "cannot initialize irq domain\n");
return -ENXIO;
}
ret = devm_add_action_or_reset(&pdev->dev, em_gio_irq_domain_remove,
p->irq_domain);
if (ret)
return ret;
if (devm_request_irq(&pdev->dev, irq[0]->start,
em_gio_irq_handler, 0, name, p)) {
dev_err(&pdev->dev, "failed to request low IRQ\n");
return -ENOENT;
}
if (devm_request_irq(&pdev->dev, irq[1]->start,
em_gio_irq_handler, 0, name, p)) {
dev_err(&pdev->dev, "failed to request high IRQ\n");
return -ENOENT;
}
ret = devm_gpiochip_add_data(&pdev->dev, gpio_chip, p);
if (ret) {
dev_err(&pdev->dev, "failed to add GPIO controller\n");
return ret;
}
return 0;
}
static const struct of_device_id em_gio_dt_ids[] = {
{ .compatible = "renesas,em-gio", },
{},
};
MODULE_DEVICE_TABLE(of, em_gio_dt_ids);
static struct platform_driver em_gio_device_driver = {
.probe = em_gio_probe,
.driver = {
.name = "em_gio",
.of_match_table = em_gio_dt_ids,
}
};
static int __init em_gio_init(void)
{
return platform_driver_register(&em_gio_device_driver);
}
postcore_initcall(em_gio_init);
static void __exit em_gio_exit(void)
{
platform_driver_unregister(&em_gio_device_driver);
}
module_exit(em_gio_exit);
MODULE_AUTHOR("Magnus Damm");
MODULE_DESCRIPTION("Renesas Emma Mobile GIO Driver");
MODULE_LICENSE("GPL v2");