linux/drivers/gpio/gpio-tb10x.c
Schspa Shi 3c938cc5ce gpio: use raw spinlock for gpio chip shadowed data
In case of PREEMPT_RT, there is a raw_spinlock -> spinlock dependency
as the lockdep report shows.

__irq_set_handler
  irq_get_desc_buslock
    __irq_get_desc_lock
      raw_spin_lock_irqsave(&desc->lock, *flags);  // raw spinlock get here
  __irq_do_set_handler
    mask_ack_irq
      dwapb_irq_ack
        spin_lock_irqsave(&gc->bgpio_lock, flags); // sleep able spinlock
  irq_put_desc_busunlock

Replace with a raw lock to avoid BUGs. This lock is only used to access
registers, and It's safe to replace with the raw lock without bad
influence.

[   15.090359][    T1] =============================
[   15.090365][    T1] [ BUG: Invalid wait context ]
[   15.090373][    T1] 5.10.59-rt52-00983-g186a6841c682-dirty #3 Not tainted
[   15.090386][    T1] -----------------------------
[   15.090392][    T1] swapper/0/1 is trying to lock:
[   15.090402][    T1] 70ff00018507c188 (&gc->bgpio_lock){....}-{3:3}, at: _raw_spin_lock_irqsave+0x1c/0x28
[   15.090470][    T1] other info that might help us debug this:
[   15.090477][    T1] context-{5:5}
[   15.090485][    T1] 3 locks held by swapper/0/1:
[   15.090497][    T1]  #0: c2ff0001816de1a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock+0x98/0x104
[   15.090553][    T1]  #1: ffff90001485b4b8 (irq_domain_mutex){+.+.}-{4:4}, at: irq_domain_associate+0xbc/0x6d4
[   15.090606][    T1]  #2: 4bff000185d7a8e0 (lock_class){....}-{2:2}, at: _raw_spin_lock_irqsave+0x1c/0x28
[   15.090654][    T1] stack backtrace:
[   15.090661][    T1] CPU: 4 PID: 1 Comm: swapper/0 Not tainted 5.10.59-rt52-00983-g186a6841c682-dirty #3
[   15.090682][    T1] Hardware name: Horizon Robotics Journey 5 DVB (DT)
[   15.090692][    T1] Call trace:
......
[   15.090811][    T1]  _raw_spin_lock_irqsave+0x1c/0x28
[   15.090828][    T1]  dwapb_irq_ack+0xb4/0x300
[   15.090846][    T1]  __irq_do_set_handler+0x494/0xb2c
[   15.090864][    T1]  __irq_set_handler+0x74/0x114
[   15.090881][    T1]  irq_set_chip_and_handler_name+0x44/0x58
[   15.090900][    T1]  gpiochip_irq_map+0x210/0x644

Signed-off-by: Schspa Shi <schspa@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Doug Berger <opendmb@gmail.com>
Acked-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-04-25 12:10:02 +02:00

246 lines
6.3 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/* Abilis Systems MODULE DESCRIPTION
*
* Copyright (C) Abilis Systems 2013
*
* Authors: Sascha Leuenberger <sascha.leuenberger@abilis.com>
* Christian Ruppert <christian.ruppert@abilis.com>
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/gpio/driver.h>
#include <linux/slab.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/spinlock.h>
#include <linux/bitops.h>
#include <linux/pinctrl/consumer.h>
#define TB10X_GPIO_DIR_IN (0x00000000)
#define TB10X_GPIO_DIR_OUT (0x00000001)
#define OFFSET_TO_REG_DDR (0x00)
#define OFFSET_TO_REG_DATA (0x04)
#define OFFSET_TO_REG_INT_EN (0x08)
#define OFFSET_TO_REG_CHANGE (0x0C)
#define OFFSET_TO_REG_WRMASK (0x10)
#define OFFSET_TO_REG_INT_TYPE (0x14)
/**
* @base: register base address
* @domain: IRQ domain of GPIO generated interrupts managed by this controller
* @irq: Interrupt line of parent interrupt controller
* @gc: gpio_chip structure associated to this GPIO controller
*/
struct tb10x_gpio {
void __iomem *base;
struct irq_domain *domain;
int irq;
struct gpio_chip gc;
};
static inline u32 tb10x_reg_read(struct tb10x_gpio *gpio, unsigned int offs)
{
return ioread32(gpio->base + offs);
}
static inline void tb10x_reg_write(struct tb10x_gpio *gpio, unsigned int offs,
u32 val)
{
iowrite32(val, gpio->base + offs);
}
static inline void tb10x_set_bits(struct tb10x_gpio *gpio, unsigned int offs,
u32 mask, u32 val)
{
u32 r;
unsigned long flags;
raw_spin_lock_irqsave(&gpio->gc.bgpio_lock, flags);
r = tb10x_reg_read(gpio, offs);
r = (r & ~mask) | (val & mask);
tb10x_reg_write(gpio, offs, r);
raw_spin_unlock_irqrestore(&gpio->gc.bgpio_lock, flags);
}
static int tb10x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
{
struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip);
return irq_create_mapping(tb10x_gpio->domain, offset);
}
static int tb10x_gpio_irq_set_type(struct irq_data *data, unsigned int type)
{
if ((type & IRQF_TRIGGER_MASK) != IRQ_TYPE_EDGE_BOTH) {
pr_err("Only (both) edge triggered interrupts supported.\n");
return -EINVAL;
}
irqd_set_trigger_type(data, type);
return IRQ_SET_MASK_OK;
}
static irqreturn_t tb10x_gpio_irq_cascade(int irq, void *data)
{
struct tb10x_gpio *tb10x_gpio = data;
u32 r = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_CHANGE);
u32 m = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_INT_EN);
const unsigned long bits = r & m;
int i;
for_each_set_bit(i, &bits, 32)
generic_handle_domain_irq(tb10x_gpio->domain, i);
return IRQ_HANDLED;
}
static int tb10x_gpio_probe(struct platform_device *pdev)
{
struct tb10x_gpio *tb10x_gpio;
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
int ret = -EBUSY;
u32 ngpio;
if (!np)
return -EINVAL;
if (of_property_read_u32(np, "abilis,ngpio", &ngpio))
return -EINVAL;
tb10x_gpio = devm_kzalloc(dev, sizeof(*tb10x_gpio), GFP_KERNEL);
if (tb10x_gpio == NULL)
return -ENOMEM;
tb10x_gpio->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(tb10x_gpio->base))
return PTR_ERR(tb10x_gpio->base);
tb10x_gpio->gc.label =
devm_kasprintf(dev, GFP_KERNEL, "%pOF", pdev->dev.of_node);
if (!tb10x_gpio->gc.label)
return -ENOMEM;
/*
* Initialize generic GPIO with one single register for reading and setting
* the lines, no special set or clear registers and a data direction register
* wher 1 means "output".
*/
ret = bgpio_init(&tb10x_gpio->gc, dev, 4,
tb10x_gpio->base + OFFSET_TO_REG_DATA,
NULL,
NULL,
tb10x_gpio->base + OFFSET_TO_REG_DDR,
NULL,
0);
if (ret) {
dev_err(dev, "unable to init generic GPIO\n");
return ret;
}
tb10x_gpio->gc.base = -1;
tb10x_gpio->gc.parent = dev;
tb10x_gpio->gc.owner = THIS_MODULE;
/*
* ngpio is set by bgpio_init() but we override it, this .request()
* callback also overrides the one set up by generic GPIO.
*/
tb10x_gpio->gc.ngpio = ngpio;
tb10x_gpio->gc.request = gpiochip_generic_request;
tb10x_gpio->gc.free = gpiochip_generic_free;
ret = devm_gpiochip_add_data(dev, &tb10x_gpio->gc, tb10x_gpio);
if (ret < 0) {
dev_err(dev, "Could not add gpiochip.\n");
return ret;
}
platform_set_drvdata(pdev, tb10x_gpio);
if (of_find_property(np, "interrupt-controller", NULL)) {
struct irq_chip_generic *gc;
ret = platform_get_irq(pdev, 0);
if (ret < 0)
return ret;
tb10x_gpio->gc.to_irq = tb10x_gpio_to_irq;
tb10x_gpio->irq = ret;
ret = devm_request_irq(dev, ret, tb10x_gpio_irq_cascade,
IRQF_TRIGGER_NONE | IRQF_SHARED,
dev_name(dev), tb10x_gpio);
if (ret != 0)
return ret;
tb10x_gpio->domain = irq_domain_add_linear(np,
tb10x_gpio->gc.ngpio,
&irq_generic_chip_ops, NULL);
if (!tb10x_gpio->domain) {
return -ENOMEM;
}
ret = irq_alloc_domain_generic_chips(tb10x_gpio->domain,
tb10x_gpio->gc.ngpio, 1, tb10x_gpio->gc.label,
handle_edge_irq, IRQ_NOREQUEST, IRQ_NOPROBE,
IRQ_GC_INIT_MASK_CACHE);
if (ret)
return ret;
gc = tb10x_gpio->domain->gc->gc[0];
gc->reg_base = tb10x_gpio->base;
gc->chip_types[0].type = IRQ_TYPE_EDGE_BOTH;
gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit;
gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
gc->chip_types[0].chip.irq_set_type = tb10x_gpio_irq_set_type;
gc->chip_types[0].regs.ack = OFFSET_TO_REG_CHANGE;
gc->chip_types[0].regs.mask = OFFSET_TO_REG_INT_EN;
}
return 0;
}
static int tb10x_gpio_remove(struct platform_device *pdev)
{
struct tb10x_gpio *tb10x_gpio = platform_get_drvdata(pdev);
if (tb10x_gpio->gc.to_irq) {
irq_remove_generic_chip(tb10x_gpio->domain->gc->gc[0],
BIT(tb10x_gpio->gc.ngpio) - 1, 0, 0);
kfree(tb10x_gpio->domain->gc);
irq_domain_remove(tb10x_gpio->domain);
}
return 0;
}
static const struct of_device_id tb10x_gpio_dt_ids[] = {
{ .compatible = "abilis,tb10x-gpio" },
{ }
};
MODULE_DEVICE_TABLE(of, tb10x_gpio_dt_ids);
static struct platform_driver tb10x_gpio_driver = {
.probe = tb10x_gpio_probe,
.remove = tb10x_gpio_remove,
.driver = {
.name = "tb10x-gpio",
.of_match_table = tb10x_gpio_dt_ids,
}
};
module_platform_driver(tb10x_gpio_driver);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("tb10x gpio.");