A GPIO driver in Rust

As an example of what a "real" device driver in Rust would look like, Wedson Almeida Filho has posted a translation of the PL061 GPIO driver alongside the original. For ease of reading, the resulting HTML has been reformatted a bit and placed below; viewing in a wide window is recommended. C versionRust version

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2008, 2009 Provigent Ltd.
 *
 * Author: Baruch Siach <[email protected]>
 *
 * Driver for the ARM PrimeCell(tm) General Purpose Input/Output (PL061)
 *
 * Data sheet: ARM DDI 0190B, September 2000
 */
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/module.h>
#include <linux/bitops.h>
#include <linux/gpio/driver.h>
#include <linux/device.h>
#include <linux/amba/bus.h>
#include <linux/slab.h>
#include <linux/pinctrl/consumer.h>
#include <linux/pm.h>

#define GPIODIR 0x400
#define GPIOIS  0x404
#define GPIOIBE 0x408
#define GPIOIEV 0x40C
#define GPIOIE  0x410
#define GPIORIS 0x414
#define GPIOMIS 0x418
#define GPIOIC  0x41C

#define PL061_GPIO_NR	8

#ifdef CONFIG_PM
struct pl061_context_save_regs {
	u8 gpio_data;
	u8 gpio_dir;
	u8 gpio_is;
	u8 gpio_ibe;
	u8 gpio_iev;
	u8 gpio_ie;
};
#endif

struct pl061 {
	raw_spinlock_t		lock;

	void __iomem		*base;
	struct gpio_chip	gc;
	struct irq_chip		irq_chip;
	int			parent_irq;

#ifdef CONFIG_PM
	struct pl061_context_save_regs csave_regs;
#endif
};









static int pl061_get_direction(struct gpio_chip *gc, unsigned offset)
{
	struct pl061 *pl061 = gpiochip_get_data(gc);

	if (readb(pl061->base + GPIODIR) & BIT(offset))
		return GPIO_LINE_DIRECTION_OUT;

	return GPIO_LINE_DIRECTION_IN;
}

static int pl061_direction_input(struct gpio_chip *gc, unsigned offset)
{
	struct pl061 *pl061 = gpiochip_get_data(gc);
	unsigned long flags;
	unsigned char gpiodir;

	raw_spin_lock_irqsave(&pl061->lock, flags);
	gpiodir = readb(pl061->base + GPIODIR);
	gpiodir &= ~(BIT(offset));
	writeb(gpiodir, pl061->base + GPIODIR);
	raw_spin_unlock_irqrestore(&pl061->lock, flags);

	return 0;
}

static int pl061_direction_output(struct gpio_chip *gc, unsigned offset,
		int value)
{
	struct pl061 *pl061 = gpiochip_get_data(gc);
	unsigned long flags;
	unsigned char gpiodir;

	raw_spin_lock_irqsave(&pl061->lock, flags);
	writeb(!!value << offset, pl061->base + (BIT(offset + 2)));
	gpiodir = readb(pl061->base + GPIODIR);
	gpiodir |= BIT(offset);
	writeb(gpiodir, pl061->base + GPIODIR);

	/*
	 * gpio value is set again, because pl061 doesn't allow to set value of
	 * a gpio pin before configuring it in OUT mode.
	 */
	writeb(!!value << offset, pl061->base + (BIT(offset + 2)));
	raw_spin_unlock_irqrestore(&pl061->lock, flags);

	return 0;
}

static int pl061_get_value(struct gpio_chip *gc, unsigned offset)
{
	struct pl061 *pl061 = gpiochip_get_data(gc);

	return !!readb(pl061->base + (BIT(offset + 2)));
}

static void pl061_set_value(struct gpio_chip *gc, unsigned offset, int value)
{
	struct pl061 *pl061 = gpiochip_get_data(gc);

	writeb(!!value << offset, pl061->base + (BIT(offset + 2)));
}

static void pl061_irq_handler(struct irq_desc *desc)
{
	unsigned long pending;
	int offset;
	struct gpio_chip *gc = irq_desc_get_handler_data(desc);
	struct pl061 *pl061 = gpiochip_get_data(gc);
	struct irq_chip *irqchip = irq_desc_get_chip(desc);

	chained_irq_enter(irqchip, desc);

	pending = readb(pl061->base + GPIOMIS);
	if (pending) {
		for_each_set_bit(offset, &pending, PL061_GPIO_NR)
			generic_handle_irq(irq_find_mapping(gc->irq.domain,
							    offset));
	}

	chained_irq_exit(irqchip, desc);
}

static int pl061_irq_type(struct irq_data *d, unsigned trigger)
{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
	struct pl061 *pl061 = gpiochip_get_data(gc);
	int offset = irqd_to_hwirq(d);
	unsigned long flags;
	u8 gpiois, gpioibe, gpioiev;
	u8 bit = BIT(offset);

	if (offset < 0 || offset >= PL061_GPIO_NR)
		return -EINVAL;

	if ((trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) &&
	    (trigger & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING)))
	{
		dev_err(gc->parent,
			"trying to configure line %d for both level and edge "
			"detection, choose one!\n",
			offset);
		return -EINVAL;
	}


	raw_spin_lock_irqsave(&pl061->lock, flags);

	gpioiev = readb(pl061->base + GPIOIEV);
	gpiois = readb(pl061->base + GPIOIS);
	gpioibe = readb(pl061->base + GPIOIBE);

	if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
		bool polarity = trigger & IRQ_TYPE_LEVEL_HIGH;

		/* Disable edge detection */
		gpioibe &= ~bit;
		/* Enable level detection */
		gpiois |= bit;
		/* Select polarity */
		if (polarity)
			gpioiev |= bit;
		else
			gpioiev &= ~bit;
		irq_set_handler_locked(d, handle_level_irq);
		dev_dbg(gc->parent, "line %d: IRQ on %s level\n",
			offset,
			polarity ? "HIGH" : "LOW");
	} else if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
		/* Disable level detection */
		gpiois &= ~bit;
		/* Select both edges, setting this makes GPIOEV be ignored */
		gpioibe |= bit;
		irq_set_handler_locked(d, handle_edge_irq);
		dev_dbg(gc->parent, "line %d: IRQ on both edges\n", offset);
	} else if ((trigger & IRQ_TYPE_EDGE_RISING) ||
		   (trigger & IRQ_TYPE_EDGE_FALLING)) {
		bool rising = trigger & IRQ_TYPE_EDGE_RISING;

		/* Disable level detection */
		gpiois &= ~bit;
		/* Clear detection on both edges */
		gpioibe &= ~bit;
		/* Select edge */
		if (rising)
			gpioiev |= bit;
		else
			gpioiev &= ~bit;
		irq_set_handler_locked(d, handle_edge_irq);
		dev_dbg(gc->parent, "line %d: IRQ on %s edge\n",
			offset,
			rising ? "RISING" : "FALLING");
	} else {
		/* No trigger: disable everything */
		gpiois &= ~bit;
		gpioibe &= ~bit;
		gpioiev &= ~bit;
		irq_set_handler_locked(d, handle_bad_irq);
		dev_warn(gc->parent, "no trigger selected for line %d\n",
			 offset);
	}

	writeb(gpiois, pl061->base + GPIOIS);
	writeb(gpioibe, pl061->base + GPIOIBE);
	writeb(gpioiev, pl061->base + GPIOIEV);

	raw_spin_unlock_irqrestore(&pl061->lock, flags);

	return 0;
}

static void pl061_irq_mask(struct irq_data *d)
{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
	struct pl061 *pl061 = gpiochip_get_data(gc);
	u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);
	u8 gpioie;

	raw_spin_lock(&pl061->lock);
	gpioie = readb(pl061->base + GPIOIE) & ~mask;
	writeb(gpioie, pl061->base + GPIOIE);
	raw_spin_unlock(&pl061->lock);
}

static void pl061_irq_unmask(struct irq_data *d)
{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
	struct pl061 *pl061 = gpiochip_get_data(gc);
	u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);
	u8 gpioie;

	raw_spin_lock(&pl061->lock);
	gpioie = readb(pl061->base + GPIOIE) | mask;
	writeb(gpioie, pl061->base + GPIOIE);
	raw_spin_unlock(&pl061->lock);
}

/**
 * pl061_irq_ack() - ACK an edge IRQ
 * @d: IRQ data for this IRQ
 *
 * This gets called from the edge IRQ handler to ACK the edge IRQ
 * in the GPIOIC (interrupt-clear) register. For level IRQs this is
 * not needed: these go away when the level signal goes away.
 */
static void pl061_irq_ack(struct irq_data *d)
{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
	struct pl061 *pl061 = gpiochip_get_data(gc);
	u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);

	raw_spin_lock(&pl061->lock);
	writeb(mask, pl061->base + GPIOIC);
	raw_spin_unlock(&pl061->lock);
}

static int pl061_irq_set_wake(struct irq_data *d, unsigned int state)
{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
	struct pl061 *pl061 = gpiochip_get_data(gc);

	return irq_set_irq_wake(pl061->parent_irq, state);
}







static int pl061_probe(struct amba_device *adev, const struct amba_id *id)
{
	struct device *dev = &adev->dev;
	struct pl061 *pl061;
	struct gpio_irq_chip *girq;
	int ret, irq;

	pl061 = devm_kzalloc(dev, sizeof(*pl061), GFP_KERNEL);
	if (pl061 == NULL)
		return -ENOMEM;

	pl061->base = devm_ioremap_resource(dev, &adev->res);
	if (IS_ERR(pl061->base))
		return PTR_ERR(pl061->base);

	raw_spin_lock_init(&pl061->lock);
	pl061->gc.request = gpiochip_generic_request;
	pl061->gc.free = gpiochip_generic_free;
	pl061->gc.base = -1;
	pl061->gc.get_direction = pl061_get_direction;
	pl061->gc.direction_input = pl061_direction_input;
	pl061->gc.direction_output = pl061_direction_output;
	pl061->gc.get = pl061_get_value;
	pl061->gc.set = pl061_set_value;
	pl061->gc.ngpio = PL061_GPIO_NR;
	pl061->gc.label = dev_name(dev);
	pl061->gc.parent = dev;
	pl061->gc.owner = THIS_MODULE;

	/*
	 * irq_chip support
	 */
	pl061->irq_chip.name = dev_name(dev);
	pl061->irq_chip.irq_ack	= pl061_irq_ack;
	pl061->irq_chip.irq_mask = pl061_irq_mask;
	pl061->irq_chip.irq_unmask = pl061_irq_unmask;
	pl061->irq_chip.irq_set_type = pl061_irq_type;
	pl061->irq_chip.irq_set_wake = pl061_irq_set_wake;

	writeb(0, pl061->base + GPIOIE); /* disable irqs */
	irq = adev->irq[0];
	if (!irq)
		dev_warn(&adev->dev, "IRQ support disabled\n");
	pl061->parent_irq = irq;

	girq = &pl061->gc.irq;
	girq->chip = &pl061->irq_chip;
	girq->parent_handler = pl061_irq_handler;
	girq->num_parents = 1;
	girq->parents = devm_kcalloc(dev, 1, sizeof(*girq->parents),
				     GFP_KERNEL);
	if (!girq->parents)
		return -ENOMEM;
	girq->parents[0] = irq;
	girq->default_type = IRQ_TYPE_NONE;
	girq->handler = handle_bad_irq;

	ret = devm_gpiochip_add_data(dev, &pl061->gc, pl061);
	if (ret)
		return ret;

	amba_set_drvdata(adev, pl061);
	dev_info(dev, "PL061 GPIO chip registered\n");

	return 0;
}

#ifdef CONFIG_PM
static int pl061_suspend(struct device *dev)
{
	struct pl061 *pl061 = dev_get_drvdata(dev);
	int offset;

	pl061->csave_regs.gpio_data = 0;
	pl061->csave_regs.gpio_dir = readb(pl061->base + GPIODIR);
	pl061->csave_regs.gpio_is = readb(pl061->base + GPIOIS);
	pl061->csave_regs.gpio_ibe = readb(pl061->base + GPIOIBE);
	pl061->csave_regs.gpio_iev = readb(pl061->base + GPIOIEV);
	pl061->csave_regs.gpio_ie = readb(pl061->base + GPIOIE);

	for (offset = 0; offset < PL061_GPIO_NR; offset++) {
		if (pl061->csave_regs.gpio_dir & (BIT(offset)))
			pl061->csave_regs.gpio_data |=
				pl061_get_value(&pl061->gc, offset) << offset;
	}

	return 0;
}

static int pl061_resume(struct device *dev)
{
	struct pl061 *pl061 = dev_get_drvdata(dev);
	int offset;

	for (offset = 0; offset < PL061_GPIO_NR; offset++) {
		if (pl061->csave_regs.gpio_dir & (BIT(offset)))
			pl061_direction_output(&pl061->gc, offset,
					pl061->csave_regs.gpio_data &
					(BIT(offset)));
		else
			pl061_direction_input(&pl061->gc, offset);
	}

	writeb(pl061->csave_regs.gpio_is, pl061->base + GPIOIS);
	writeb(pl061->csave_regs.gpio_ibe, pl061->base + GPIOIBE);
	writeb(pl061->csave_regs.gpio_iev, pl061->base + GPIOIEV);
	writeb(pl061->csave_regs.gpio_ie, pl061->base + GPIOIE);

	return 0;
}

static const struct dev_pm_ops pl061_dev_pm_ops = {
	.suspend = pl061_suspend,
	.resume = pl061_resume,
	.freeze = pl061_suspend,
	.restore = pl061_resume,
};
#endif

static const struct amba_id pl061_ids[] = {
	{
		.id	= 0x00041061,
		.mask	= 0x000fffff,
	},
	{ 0, 0 },
};
MODULE_DEVICE_TABLE(amba, pl061_ids);

static struct amba_driver pl061_gpio_driver = {
	.drv = {
		.name	= "pl061_gpio",
#ifdef CONFIG_PM
		.pm	= &pl061_dev_pm_ops,
#endif
	},
	.id_table	= pl061_ids,
	.probe		= pl061_probe,
};
module_amba_driver(pl061_gpio_driver);

MODULE_LICENSE("GPL v2");

// SPDX-License-Identifier: GPL-2.0

//! Driver for the ARM PrimeCell(tm) General Purpose Input/Output (PL061).
//!
//! Based on the C driver written by Baruch Siach <[email protected]>.

#![no_std]
#![feature(global_asm, allocator_api)]


use core::ops::DerefMut;
use kernel::{
    amba, bit, declare_id_table, device, gpio,
    io_mem::IoMem,
    irq::{self, IrqData, LockedIrqData},
    power,
    prelude::*,
    sync::{IrqDisableSpinLock, Ref},
};








const GPIODIR: usize = 0x400;
const GPIOIS: usize = 0x404;
const GPIOIBE: usize = 0x408;
const GPIOIEV: usize = 0x40C;
const GPIOIE: usize = 0x410;
const GPIOMIS: usize = 0x418;
const GPIOIC: usize = 0x41C;
const GPIO_SIZE: usize = 0x1000;

const PL061_GPIO_NR: u16 = 8;

#[derive(Default)]
struct ContextSaveRegs {
    gpio_data: u8,
    gpio_dir: u8,
    gpio_is: u8,
    gpio_ibe: u8,
    gpio_iev: u8,
    gpio_ie: u8,
}

#[derive(Default)]
struct PL061Data {
    csave_regs: ContextSaveRegs,
}

struct PL061Resources {
    base: IoMem<GPIO_SIZE>,
    parent_irq: u32,
}

struct PL061Registrations {
    gpio_chip: gpio::ChipRegistration<PL061Device>,
}

type DeviceData = device::Data<PL061Registrations, PL061Resources, IrqDisableSpinLock<PL061Data>>;

struct PL061Device;

impl gpio::Chip for PL061Device {
    type IrqChip = Self;
    type Data = Ref<DeviceData>;

    fn get_direction(data: &Ref<DeviceData>, offset: u32) -> Result<gpio::LineDirection> {
        let pl061 = data.resources().ok_or(Error::ENXIO)?;
        Ok(if pl061.base.readb(GPIODIR) & bit(offset) != 0 {
            gpio::LineDirection::Out
        } else {
            gpio::LineDirection::In
        })
    }


    fn direction_input(data: &Ref<DeviceData>, offset: u32) -> Result {
        let _guard = data.lock();
        let pl061 = data.resources().ok_or(Error::ENXIO)?;
        let mut gpiodir = pl061.base.readb(GPIODIR);
        gpiodir &= !bit(offset);
        pl061.base.writeb(gpiodir, GPIODIR);
        Ok(())
    }







    fn direction_output(data: &Ref<DeviceData>, offset: u32, value: bool) -> Result {
        let woffset = bit(offset + 2).into();
        let _guard = data.lock();
        let pl061 = data.resources().ok_or(Error::ENXIO)?;
        pl061.base.try_writeb((value as u8) << offset, woffset)?;
        let mut gpiodir = pl061.base.readb(GPIODIR);
        gpiodir |= bit(offset);
        pl061.base.writeb(gpiodir, GPIODIR);

        // gpio value is set again, because pl061 doesn't allow to set value of a gpio pin before
        // configuring it in OUT mode.
        pl061.base.try_writeb((value as u8) << offset, woffset)?;
        Ok(())
    }









    fn get(data: &Ref<DeviceData>, offset: u32) -> Result<bool> {
        let pl061 = data.resources().ok_or(Error::ENXIO)?;
        Ok(pl061.base.try_readb(bit(offset + 2).into())? != 0)
    }



    fn set(data: &Ref<DeviceData>, offset: u32, value: bool) {
        if let Some(pl061) = data.resources() {
            let woffset = bit(offset + 2).into();
            let _ = pl061.base.try_writeb((value as u8) << offset, woffset);
        }
    }

    fn irq_route(data: &Ref<DeviceData>, router: &gpio::IrqRouter) {
        if let Some(pl061) = data.resources() {
            let pending = pl061.base.readb(GPIOMIS);
            if pending != 0 {
                for offset in 0..PL061_GPIO_NR {
                    if pending & bit(offset) != 0 {
                        router.deliver(offset.into());
                    }
                }
            }
        }
    }
}

impl irq::Chip for PL061Device {
    type Data = Ref<DeviceData>;




    fn set_type(data: &Ref<DeviceData>, irq_data: &mut LockedIrqData, trigger: u32) -> Result {
        let offset = irq_data.hwirq();
        let bit = bit(offset);

        if offset >= PL061_GPIO_NR.into() {
            return Err(Error::EINVAL);
        }

        if trigger & (irq::TYPE_LEVEL_HIGH | irq::TYPE_LEVEL_LOW) != 0
            && trigger & (irq::TYPE_EDGE_RISING | irq::TYPE_EDGE_FALLING) != 0
        {
            pr_err!(
                "trying to configure line {} for both level and edge detection, choose one!\n",
                offset
            );
            return Err(Error::EINVAL);
        }

        let _guard = data.lock();
        let pl061 = data.resources().ok_or(Error::ENXIO)?;

        let mut gpioiev = pl061.base.readb(GPIOIEV);
        let mut gpiois = pl061.base.readb(GPIOIS);
        let mut gpioibe = pl061.base.readb(GPIOIBE);

        if trigger & (irq::TYPE_LEVEL_HIGH | irq::TYPE_LEVEL_LOW) != 0 {
            let polarity = trigger & irq::TYPE_LEVEL_HIGH != 0;

            // Disable edge detection.
            gpioibe &= !bit;
            // Enable level detection.
            gpiois |= bit;
            // Select polarity.
            if polarity {
                gpioiev |= bit;
            } else {
                gpioiev &= !bit;
            }
            irq_data.set_level_handler();
            pr_debug!(
                "line {}: IRQ on {} level\n",
                offset,
                if polarity { "HIGH" } else { "LOW" }
            );
        } else if (trigger & irq::TYPE_EDGE_BOTH) == irq::TYPE_EDGE_BOTH {
            // Disable level detection.
            gpiois &= !bit;
            // Select both edges, settings this makes GPIOEV be ignored.
            gpioibe |= bit;
            irq_data.set_edge_handler();
            pr_debug!("line {}: IRQ on both edges\n", offset);
        } else if trigger & (irq::TYPE_EDGE_RISING | irq::TYPE_EDGE_FALLING) != 0 {
            let rising = trigger & irq::TYPE_EDGE_RISING != 0;

            // Disable level detection.
            gpiois &= !bit;
            // Clear detection on both edges.
            gpioibe &= !bit;
            // Select edge.
            if rising {
                gpioiev |= bit;
            } else {
                gpioiev &= !bit;
            }
            irq_data.set_edge_handler();
            pr_debug!(
                "line {}: IRQ on {} edge\n",
                offset,
                if rising { "RISING" } else { "FALLING}" }
            );
        } else {
            // No trigger: disable everything.
            gpiois &= !bit;
            gpioibe &= !bit;
            gpioiev &= !bit;
            irq_data.set_bad_handler();
            pr_warn!("no trigger selected for line {}\n", offset);
        }

        pl061.base.writeb(gpioiev, GPIOIEV);
        pl061.base.writeb(gpiois, GPIOIS);
        pl061.base.writeb(gpioibe, GPIOIBE);

        Ok(())
    }



    fn mask(data: &Ref<DeviceData>, irq_data: &IrqData) {
        let mask = bit(irq_data.hwirq() % u64::from(PL061_GPIO_NR));
        let _guard = data.lock();
        if let Some(pl061) = data.resources() {
            let gpioie = pl061.base.readb(GPIOIE) & !mask;
            let _ = pl061.base.try_writeb(gpioie, GPIOIE);
        }
    }





    fn unmask(data: &Ref<DeviceData>, irq_data: &IrqData) {
        let mask = bit(irq_data.hwirq() % u64::from(PL061_GPIO_NR));
        let _guard = data.lock();
        if let Some(pl061) = data.resources() {
            let gpioie = pl061.base.readb(GPIOIE) | mask;
            let _ = pl061.base.try_writeb(gpioie, GPIOIE);
        }
    }









    // This gets called from the edge IRQ handler to ACK the edge IRQ in the GPIOIC
    // (interrupt-clear) register. For level IRQs this is not needed: these go away when the level
    // signal goes away.
    fn ack(data: &Ref<DeviceData>, irq_data: &IrqData) {
        let mask = bit(irq_data.hwirq() % u64::from(PL061_GPIO_NR));
        let _guard = data.lock();
        if let Some(pl061) = data.resources() {
            let _ = pl061.base.try_writeb(mask.into(), GPIOIC);
        }
    }





    fn set_wake(data: &Ref<DeviceData>, _irq_data: &IrqData, on: bool) -> Result {
        let pl061 = data.resources().ok_or(Error::ENXIO)?;
        irq::set_irq_wake(pl061.parent_irq, on)
    }
}

impl amba::Driver for PL061Device {
    type InnerData = DeviceData;
    type PowerOps = Self;

    declare_id_table! {
        (0x00041061, 0x000fffff),
    }

    fn probe(
        dev: &mut amba::Device,
        _id: &(u32, u32, Option<Self::IdInfo>),
    ) -> Result<Ref<DeviceData>> {
        let res = dev.take_resource().ok_or(Error::ENXIO)?;
        let irq = dev.irq(0).ok_or(Error::ENXIO)?;

        let data = Ref::try_new_and_init(
            device::Data::new(
                PL061Registrations {
                    gpio_chip: gpio::ChipRegistration::default(),
                },
                PL061Resources {
                    base: IoMem::try_new(res)?,
                    parent_irq: irq,
                },
                // SAFETY: We call `irqsave_spinlock_init` below.
                unsafe { IrqDisableSpinLock::new(PL061Data::default()) },
            ),
            |mut data| {
                // SAFETY: General part of the data is pinned when `data` is.
                let gen = unsafe { data.as_mut().map_unchecked_mut(|d| d.deref_mut()) };
                kernel::irqdisable_spinlock_init!(gen, "PL061::General");
            },
        )?;

        data.resources().ok_or(Error::ENXIO)?.base.writeb(0, GPIOIE); // disable irqs
        data.registrations()
            .ok_or(Error::ENXIO)?
            .gpio_chip
            .register_with_irq(PL061_GPIO_NR, None, dev, data.clone(), irq)?;

        pr_info!("PL061 GPIO chip registered\n");

        Ok(data)
    }
}

impl power::Operations for PL061Device {
    type Data = Ref<DeviceData>;




























    fn suspend(data: &Ref<DeviceData>) -> Result {
        let mut inner = data.lock();
        let pl061 = data.resources().ok_or(Error::ENXIO)?;
        inner.csave_regs.gpio_data = 0;
        inner.csave_regs.gpio_dir = pl061.base.readb(GPIODIR);
        inner.csave_regs.gpio_is = pl061.base.readb(GPIOIS);
        inner.csave_regs.gpio_ibe = pl061.base.readb(GPIOIBE);
        inner.csave_regs.gpio_iev = pl061.base.readb(GPIOIEV);
        inner.csave_regs.gpio_ie = pl061.base.readb(GPIOIE);

        for offset in 0..PL061_GPIO_NR {
            if inner.csave_regs.gpio_dir & bit(offset) != 0 {
                if let Ok(v) = <Self as gpio::Chip>::get(data, offset.into()) {
                    inner.csave_regs.gpio_data |= (v as u8) << offset;
                }
            }
        }

        Ok(())
    }

    fn resume(data: &Ref<DeviceData>) -> Result {
        let inner = data.lock();
        let pl061 = data.resources().ok_or(Error::ENXIO)?;

        for offset in 0..PL061_GPIO_NR {
            if inner.csave_regs.gpio_dir & bit(offset) != 0 {
                let value = inner.csave_regs.gpio_data & bit(offset) != 0;
                let _ = <Self as gpio::Chip>::direction_output(data, offset.into(), value);
            } else {
                let _ = <Self as gpio::Chip>::direction_input(data, offset.into());
            }
        }

        pl061.base.writeb(inner.csave_regs.gpio_is, GPIOIS);
        pl061.base.writeb(inner.csave_regs.gpio_ibe, GPIOIBE);
        pl061.base.writeb(inner.csave_regs.gpio_iev, GPIOIEV);
        pl061.base.writeb(inner.csave_regs.gpio_ie, GPIOIE);

        Ok(())
    }

    fn freeze(data: &Ref<DeviceData>) -> Result {
        Self::suspend(data)
    }

    fn restore(data: &Ref<DeviceData>) -> Result {
        Self::resume(data)
    }
}




















module_amba_driver! {
    type: PL061Device,
    name: b"pl061_gpio",
    author: b"Wedson Almeida Filho",
    license: b"GPL v2",
}