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![Marek Vasut](/assets/img/avatar_default.png)
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>
358 lines
9.4 KiB
C
358 lines
9.4 KiB
C
/*
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* MXC GPIO support. (c) 2008 Daniel Mack <daniel@caiaq.de>
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* Copyright 2008 Juergen Beisert, kernel@pengutronix.de
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*
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* Based on code from Freescale,
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* Copyright (C) 2004-2010 Freescale Semiconductor, Inc. All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
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* MA 02110-1301, USA.
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*/
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/io.h>
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#include <linux/irq.h>
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#include <linux/irqdomain.h>
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#include <linux/gpio.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include <linux/of_device.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/basic_mmio_gpio.h>
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#include <linux/module.h>
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#define MXS_SET 0x4
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#define MXS_CLR 0x8
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#define PINCTRL_DOUT(p) ((is_imx23_gpio(p) ? 0x0500 : 0x0700) + (p->id) * 0x10)
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#define PINCTRL_DIN(p) ((is_imx23_gpio(p) ? 0x0600 : 0x0900) + (p->id) * 0x10)
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#define PINCTRL_DOE(p) ((is_imx23_gpio(p) ? 0x0700 : 0x0b00) + (p->id) * 0x10)
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#define PINCTRL_PIN2IRQ(p) ((is_imx23_gpio(p) ? 0x0800 : 0x1000) + (p->id) * 0x10)
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#define PINCTRL_IRQEN(p) ((is_imx23_gpio(p) ? 0x0900 : 0x1100) + (p->id) * 0x10)
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#define PINCTRL_IRQLEV(p) ((is_imx23_gpio(p) ? 0x0a00 : 0x1200) + (p->id) * 0x10)
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#define PINCTRL_IRQPOL(p) ((is_imx23_gpio(p) ? 0x0b00 : 0x1300) + (p->id) * 0x10)
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#define PINCTRL_IRQSTAT(p) ((is_imx23_gpio(p) ? 0x0c00 : 0x1400) + (p->id) * 0x10)
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#define GPIO_INT_FALL_EDGE 0x0
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#define GPIO_INT_LOW_LEV 0x1
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#define GPIO_INT_RISE_EDGE 0x2
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#define GPIO_INT_HIGH_LEV 0x3
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#define GPIO_INT_LEV_MASK (1 << 0)
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#define GPIO_INT_POL_MASK (1 << 1)
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enum mxs_gpio_id {
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IMX23_GPIO,
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IMX28_GPIO,
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};
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struct mxs_gpio_port {
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void __iomem *base;
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int id;
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int irq;
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struct irq_domain *domain;
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struct bgpio_chip bgc;
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enum mxs_gpio_id devid;
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u32 both_edges;
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};
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static inline int is_imx23_gpio(struct mxs_gpio_port *port)
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{
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return port->devid == IMX23_GPIO;
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}
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static inline int is_imx28_gpio(struct mxs_gpio_port *port)
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{
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return port->devid == IMX28_GPIO;
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}
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/* Note: This driver assumes 32 GPIOs are handled in one register */
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static int mxs_gpio_set_irq_type(struct irq_data *d, unsigned int type)
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{
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u32 val;
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u32 pin_mask = 1 << d->hwirq;
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struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
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struct mxs_gpio_port *port = gc->private;
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void __iomem *pin_addr;
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int edge;
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port->both_edges &= ~pin_mask;
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switch (type) {
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case IRQ_TYPE_EDGE_BOTH:
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val = gpio_get_value(port->bgc.gc.base + d->hwirq);
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if (val)
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edge = GPIO_INT_FALL_EDGE;
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else
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edge = GPIO_INT_RISE_EDGE;
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port->both_edges |= pin_mask;
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break;
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case IRQ_TYPE_EDGE_RISING:
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edge = GPIO_INT_RISE_EDGE;
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break;
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case IRQ_TYPE_EDGE_FALLING:
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edge = GPIO_INT_FALL_EDGE;
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break;
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case IRQ_TYPE_LEVEL_LOW:
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edge = GPIO_INT_LOW_LEV;
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break;
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case IRQ_TYPE_LEVEL_HIGH:
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edge = GPIO_INT_HIGH_LEV;
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break;
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default:
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return -EINVAL;
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}
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/* set level or edge */
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pin_addr = port->base + PINCTRL_IRQLEV(port);
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if (edge & GPIO_INT_LEV_MASK)
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writel(pin_mask, pin_addr + MXS_SET);
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else
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writel(pin_mask, pin_addr + MXS_CLR);
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/* set polarity */
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pin_addr = port->base + PINCTRL_IRQPOL(port);
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if (edge & GPIO_INT_POL_MASK)
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writel(pin_mask, pin_addr + MXS_SET);
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else
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writel(pin_mask, pin_addr + MXS_CLR);
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writel(pin_mask,
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port->base + PINCTRL_IRQSTAT(port) + MXS_CLR);
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return 0;
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}
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static void mxs_flip_edge(struct mxs_gpio_port *port, u32 gpio)
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{
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u32 bit, val, edge;
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void __iomem *pin_addr;
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bit = 1 << gpio;
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pin_addr = port->base + PINCTRL_IRQPOL(port);
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val = readl(pin_addr);
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edge = val & bit;
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if (edge)
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writel(bit, pin_addr + MXS_CLR);
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else
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writel(bit, pin_addr + MXS_SET);
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}
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/* MXS has one interrupt *per* gpio port */
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static void mxs_gpio_irq_handler(u32 irq, struct irq_desc *desc)
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{
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u32 irq_stat;
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struct mxs_gpio_port *port = irq_get_handler_data(irq);
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desc->irq_data.chip->irq_ack(&desc->irq_data);
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irq_stat = readl(port->base + PINCTRL_IRQSTAT(port)) &
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readl(port->base + PINCTRL_IRQEN(port));
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while (irq_stat != 0) {
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int irqoffset = fls(irq_stat) - 1;
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if (port->both_edges & (1 << irqoffset))
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mxs_flip_edge(port, irqoffset);
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generic_handle_irq(irq_find_mapping(port->domain, irqoffset));
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irq_stat &= ~(1 << irqoffset);
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}
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}
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/*
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* Set interrupt number "irq" in the GPIO as a wake-up source.
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* While system is running, all registered GPIO interrupts need to have
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* wake-up enabled. When system is suspended, only selected GPIO interrupts
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* need to have wake-up enabled.
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* @param irq interrupt source number
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* @param enable enable as wake-up if equal to non-zero
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* @return This function returns 0 on success.
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*/
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static int mxs_gpio_set_wake_irq(struct irq_data *d, unsigned int enable)
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{
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struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
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struct mxs_gpio_port *port = gc->private;
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if (enable)
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enable_irq_wake(port->irq);
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else
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disable_irq_wake(port->irq);
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return 0;
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}
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static void __init mxs_gpio_init_gc(struct mxs_gpio_port *port, int irq_base)
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{
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struct irq_chip_generic *gc;
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struct irq_chip_type *ct;
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gc = irq_alloc_generic_chip("gpio-mxs", 1, irq_base,
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port->base, handle_level_irq);
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gc->private = port;
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ct = gc->chip_types;
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ct->chip.irq_ack = irq_gc_ack_set_bit;
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ct->chip.irq_mask = irq_gc_mask_clr_bit;
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ct->chip.irq_unmask = irq_gc_mask_set_bit;
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ct->chip.irq_set_type = mxs_gpio_set_irq_type;
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ct->chip.irq_set_wake = mxs_gpio_set_wake_irq;
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ct->regs.ack = PINCTRL_IRQSTAT(port) + MXS_CLR;
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ct->regs.mask = PINCTRL_IRQEN(port);
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irq_setup_generic_chip(gc, IRQ_MSK(32), IRQ_GC_INIT_NESTED_LOCK,
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IRQ_NOREQUEST, 0);
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}
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static int mxs_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
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{
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struct bgpio_chip *bgc = to_bgpio_chip(gc);
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struct mxs_gpio_port *port =
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container_of(bgc, struct mxs_gpio_port, bgc);
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return irq_find_mapping(port->domain, offset);
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}
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static struct platform_device_id mxs_gpio_ids[] = {
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{
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.name = "imx23-gpio",
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.driver_data = IMX23_GPIO,
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}, {
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.name = "imx28-gpio",
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.driver_data = IMX28_GPIO,
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}, {
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/* sentinel */
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}
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};
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MODULE_DEVICE_TABLE(platform, mxs_gpio_ids);
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static const struct of_device_id mxs_gpio_dt_ids[] = {
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{ .compatible = "fsl,imx23-gpio", .data = (void *) IMX23_GPIO, },
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{ .compatible = "fsl,imx28-gpio", .data = (void *) IMX28_GPIO, },
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{ /* sentinel */ }
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};
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MODULE_DEVICE_TABLE(of, mxs_gpio_dt_ids);
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static int mxs_gpio_probe(struct platform_device *pdev)
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{
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const struct of_device_id *of_id =
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of_match_device(mxs_gpio_dt_ids, &pdev->dev);
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struct device_node *np = pdev->dev.of_node;
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struct device_node *parent;
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static void __iomem *base;
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struct mxs_gpio_port *port;
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int irq_base;
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int err;
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port = devm_kzalloc(&pdev->dev, sizeof(*port), GFP_KERNEL);
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if (!port)
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return -ENOMEM;
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port->id = of_alias_get_id(np, "gpio");
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if (port->id < 0)
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return port->id;
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port->devid = (enum mxs_gpio_id) of_id->data;
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port->irq = platform_get_irq(pdev, 0);
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if (port->irq < 0)
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return port->irq;
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/*
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* map memory region only once, as all the gpio ports
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* share the same one
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*/
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if (!base) {
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parent = of_get_parent(np);
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base = of_iomap(parent, 0);
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of_node_put(parent);
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if (!base)
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return -EADDRNOTAVAIL;
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}
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port->base = base;
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/*
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* select the pin interrupt functionality but initially
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* disable the interrupts
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*/
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writel(~0U, port->base + PINCTRL_PIN2IRQ(port));
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writel(0, port->base + PINCTRL_IRQEN(port));
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/* clear address has to be used to clear IRQSTAT bits */
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writel(~0U, port->base + PINCTRL_IRQSTAT(port) + MXS_CLR);
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irq_base = irq_alloc_descs(-1, 0, 32, numa_node_id());
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if (irq_base < 0)
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return irq_base;
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port->domain = irq_domain_add_legacy(np, 32, irq_base, 0,
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&irq_domain_simple_ops, NULL);
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if (!port->domain) {
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err = -ENODEV;
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goto out_irqdesc_free;
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}
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/* gpio-mxs can be a generic irq chip */
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mxs_gpio_init_gc(port, irq_base);
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/* setup one handler for each entry */
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irq_set_chained_handler(port->irq, mxs_gpio_irq_handler);
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irq_set_handler_data(port->irq, port);
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err = bgpio_init(&port->bgc, &pdev->dev, 4,
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port->base + PINCTRL_DIN(port),
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port->base + PINCTRL_DOUT(port) + MXS_SET,
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port->base + PINCTRL_DOUT(port) + MXS_CLR,
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port->base + PINCTRL_DOE(port), NULL, 0);
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if (err)
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goto out_irqdesc_free;
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port->bgc.gc.to_irq = mxs_gpio_to_irq;
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port->bgc.gc.base = port->id * 32;
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err = gpiochip_add(&port->bgc.gc);
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if (err)
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goto out_bgpio_remove;
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return 0;
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out_bgpio_remove:
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bgpio_remove(&port->bgc);
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out_irqdesc_free:
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irq_free_descs(irq_base, 32);
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return err;
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}
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static struct platform_driver mxs_gpio_driver = {
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.driver = {
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.name = "gpio-mxs",
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.owner = THIS_MODULE,
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.of_match_table = mxs_gpio_dt_ids,
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},
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.probe = mxs_gpio_probe,
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.id_table = mxs_gpio_ids,
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};
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static int __init mxs_gpio_init(void)
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{
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return platform_driver_register(&mxs_gpio_driver);
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}
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postcore_initcall(mxs_gpio_init);
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MODULE_AUTHOR("Freescale Semiconductor, "
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"Daniel Mack <danielncaiaq.de>, "
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"Juergen Beisert <kernel@pengutronix.de>");
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MODULE_DESCRIPTION("Freescale MXS GPIO");
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MODULE_LICENSE("GPL");
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