kernel-ark/drivers/gpio/gpio-mxs.c
Marek Vasut a585f87c86 gpio: mxs: Allow for recursive enable_irq_wake() call
The scenario here is that someone calls enable_irq_wake() from somewhere
in the code. This will result in the lockdep producing a backtrace as can
be seen below. In my case, this problem is triggered when using the wl1271
(TI WlCore) driver found in drivers/net/wireless/ti/ .

The problem cause is rather obvious from the backtrace, but let's outline
the dependency. enable_irq_wake() grabs the IRQ buslock in irq_set_irq_wake(),
which in turns calls mxs_gpio_set_wake_irq() . But mxs_gpio_set_wake_irq()
calls enable_irq_wake() again on the one-level-higher IRQ , thus it tries to
grab the IRQ buslock again in irq_set_irq_wake() . Because the spinlock in
irq_set_irq_wake()->irq_get_desc_buslock()->__irq_get_desc_lock() is not
marked as recursive, lockdep will spew the stuff below.

We know we can safely re-enter the lock, so use IRQ_GC_INIT_NESTED_LOCK to
fix the spew.

 =============================================
 [ INFO: possible recursive locking detected ]
 3.10.33-00012-gf06b763-dirty #61 Not tainted
 ---------------------------------------------
 kworker/0:1/18 is trying to acquire lock:
  (&irq_desc_lock_class){-.-...}, at: [<c00685f0>] __irq_get_desc_lock+0x48/0x88

 but task is already holding lock:
  (&irq_desc_lock_class){-.-...}, at: [<c00685f0>] __irq_get_desc_lock+0x48/0x88

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(&irq_desc_lock_class);
   lock(&irq_desc_lock_class);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

 3 locks held by kworker/0:1/18:
  #0:  (events){.+.+.+}, at: [<c0036308>] process_one_work+0x134/0x4a4
  #1:  ((&fw_work->work)){+.+.+.}, at: [<c0036308>] process_one_work+0x134/0x4a4
  #2:  (&irq_desc_lock_class){-.-...}, at: [<c00685f0>] __irq_get_desc_lock+0x48/0x88

 stack backtrace:
 CPU: 0 PID: 18 Comm: kworker/0:1 Not tainted 3.10.33-00012-gf06b763-dirty #61
 Workqueue: events request_firmware_work_func
 [<c0013eb4>] (unwind_backtrace+0x0/0xf0) from [<c0011c74>] (show_stack+0x10/0x14)
 [<c0011c74>] (show_stack+0x10/0x14) from [<c005bb08>] (__lock_acquire+0x140c/0x1a64)
 [<c005bb08>] (__lock_acquire+0x140c/0x1a64) from [<c005c6a8>] (lock_acquire+0x9c/0x104)
 [<c005c6a8>] (lock_acquire+0x9c/0x104) from [<c051d5a4>] (_raw_spin_lock_irqsave+0x44/0x58)
 [<c051d5a4>] (_raw_spin_lock_irqsave+0x44/0x58) from [<c00685f0>] (__irq_get_desc_lock+0x48/0x88)
 [<c00685f0>] (__irq_get_desc_lock+0x48/0x88) from [<c0068e78>] (irq_set_irq_wake+0x20/0xf4)
 [<c0068e78>] (irq_set_irq_wake+0x20/0xf4) from [<c027260c>] (mxs_gpio_set_wake_irq+0x1c/0x24)
 [<c027260c>] (mxs_gpio_set_wake_irq+0x1c/0x24) from [<c0068cf4>] (set_irq_wake_real+0x30/0x44)
 [<c0068cf4>] (set_irq_wake_real+0x30/0x44) from [<c0068ee4>] (irq_set_irq_wake+0x8c/0xf4)
 [<c0068ee4>] (irq_set_irq_wake+0x8c/0xf4) from [<c0310748>] (wlcore_nvs_cb+0x10c/0x97c)
 [<c0310748>] (wlcore_nvs_cb+0x10c/0x97c) from [<c02be5e8>] (request_firmware_work_func+0x38/0x58)
 [<c02be5e8>] (request_firmware_work_func+0x38/0x58) from [<c0036394>] (process_one_work+0x1c0/0x4a4)
 [<c0036394>] (process_one_work+0x1c0/0x4a4) from [<c0036a4c>] (worker_thread+0x138/0x394)
 [<c0036a4c>] (worker_thread+0x138/0x394) from [<c003cb74>] (kthread+0xa4/0xb0)
 [<c003cb74>] (kthread+0xa4/0xb0) from [<c000ee00>] (ret_from_fork+0x14/0x34)
 wlcore: loaded

Cc: stable@vger.kernel.org
Signed-off-by: Marek Vasut <marex@denx.de>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-03-27 10:11:59 +01:00

359 lines
9.4 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/gpio.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/basic_mmio_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 bgpio_chip bgc;
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 mxs_gpio_port *port = gc->private;
void __iomem *pin_addr;
int edge;
port->both_edges &= ~pin_mask;
switch (type) {
case IRQ_TYPE_EDGE_BOTH:
val = gpio_get_value(port->bgc.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);
else
writel(pin_mask, pin_addr + MXS_CLR);
/* 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(u32 irq, struct irq_desc *desc)
{
u32 irq_stat;
struct mxs_gpio_port *port = irq_get_handler_data(irq);
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 void __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", 1, irq_base,
port->base, handle_level_irq);
gc->private = port;
ct = gc->chip_types;
ct->chip.irq_ack = irq_gc_ack_set_bit;
ct->chip.irq_mask = irq_gc_mask_clr_bit;
ct->chip.irq_unmask = irq_gc_mask_set_bit;
ct->chip.irq_set_type = mxs_gpio_set_irq_type;
ct->chip.irq_set_wake = mxs_gpio_set_wake_irq;
ct->regs.ack = PINCTRL_IRQSTAT(port) + MXS_CLR;
ct->regs.mask = PINCTRL_IRQEN(port);
irq_setup_generic_chip(gc, IRQ_MSK(32), IRQ_GC_INIT_NESTED_LOCK,
IRQ_NOREQUEST, 0);
}
static int mxs_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
{
struct bgpio_chip *bgc = to_bgpio_chip(gc);
struct mxs_gpio_port *port =
container_of(bgc, struct mxs_gpio_port, bgc);
return irq_find_mapping(port->domain, offset);
}
static 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;
/*
* select the pin interrupt functionality but initially
* disable the interrupts
*/
writel(~0U, 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 */
mxs_gpio_init_gc(port, irq_base);
/* setup one handler for each entry */
irq_set_chained_handler(port->irq, mxs_gpio_irq_handler);
irq_set_handler_data(port->irq, port);
err = bgpio_init(&port->bgc, &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_irqdesc_free;
port->bgc.gc.to_irq = mxs_gpio_to_irq;
port->bgc.gc.base = port->id * 32;
err = gpiochip_add(&port->bgc.gc);
if (err)
goto out_bgpio_remove;
return 0;
out_bgpio_remove:
bgpio_remove(&port->bgc);
out_irqdesc_free:
irq_free_descs(irq_base, 32);
return err;
}
static struct platform_driver mxs_gpio_driver = {
.driver = {
.name = "gpio-mxs",
.owner = THIS_MODULE,
.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");