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// SPDX-License-Identifier: GPL-2.0+
// Copyright (C) 2008-2009 The GameCube Linux Team
// Copyright (C) 2008,2009 Albert Herranz
// Copyright (C) 2017-2018 Jonathan Neuschäfer
//
// Nintendo Wii (Hollywood) GPIO driver
#include <linux/gpio/driver.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/slab.h>
/*
* Register names and offsets courtesy of WiiBrew:
* https://wiibrew.org/wiki/Hardware/Hollywood_GPIOs
*
* Note that for most registers, there are two versions:
* - HW_GPIOB_* Is always accessible by the Broadway PowerPC core, but does
* always give access to all GPIO lines
* - HW_GPIO_* Is only accessible by the Broadway PowerPC code if the memory
* firewall (AHBPROT) in the Hollywood chipset has been configured to allow
* such access.
*
* The ownership of each GPIO line can be configured in the HW_GPIO_OWNER
* register: A one bit configures the line for access via the HW_GPIOB_*
* registers, a zero bit indicates access via HW_GPIO_*. This driver uses
* HW_GPIOB_*.
*/
#define HW_GPIOB_OUT 0x00
#define HW_GPIOB_DIR 0x04
#define HW_GPIOB_IN 0x08
#define HW_GPIOB_INTLVL 0x0c
#define HW_GPIOB_INTFLAG 0x10
#define HW_GPIOB_INTMASK 0x14
#define HW_GPIOB_INMIR 0x18
#define HW_GPIO_ENABLE 0x1c
#define HW_GPIO_OUT 0x20
#define HW_GPIO_DIR 0x24
#define HW_GPIO_IN 0x28
#define HW_GPIO_INTLVL 0x2c
#define HW_GPIO_INTFLAG 0x30
#define HW_GPIO_INTMASK 0x34
#define HW_GPIO_INMIR 0x38
#define HW_GPIO_OWNER 0x3c
struct hlwd_gpio {
struct gpio_chip gpioc;
struct irq_chip irqc;
void __iomem *regs;
int irq;
u32 edge_emulation;
u32 rising_edge, falling_edge;
};
static void hlwd_gpio_irqhandler(struct irq_desc *desc)
{
struct hlwd_gpio *hlwd =
gpiochip_get_data(irq_desc_get_handler_data(desc));
struct irq_chip *chip = irq_desc_get_chip(desc);
unsigned long flags;
unsigned long pending;
int hwirq;
u32 emulated_pending;
spin_lock_irqsave(&hlwd->gpioc.bgpio_lock, flags);
pending = ioread32be(hlwd->regs + HW_GPIOB_INTFLAG);
pending &= ioread32be(hlwd->regs + HW_GPIOB_INTMASK);
/* Treat interrupts due to edge trigger emulation separately */
emulated_pending = hlwd->edge_emulation & pending;
pending &= ~emulated_pending;
if (emulated_pending) {
u32 level, rising, falling;
level = ioread32be(hlwd->regs + HW_GPIOB_INTLVL);
rising = level & emulated_pending;
falling = ~level & emulated_pending;
/* Invert the levels */
iowrite32be(level ^ emulated_pending,
hlwd->regs + HW_GPIOB_INTLVL);
/* Ack all emulated-edge interrupts */
iowrite32be(emulated_pending, hlwd->regs + HW_GPIOB_INTFLAG);
/* Signal interrupts only on the correct edge */
rising &= hlwd->rising_edge;
falling &= hlwd->falling_edge;
/* Mark emulated interrupts as pending */
pending |= rising | falling;
}
spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags);
chained_irq_enter(chip, desc);
for_each_set_bit(hwirq, &pending, 32) {
int irq = irq_find_mapping(hlwd->gpioc.irq.domain, hwirq);
generic_handle_irq(irq);
}
chained_irq_exit(chip, desc);
}
static void hlwd_gpio_irq_ack(struct irq_data *data)
{
struct hlwd_gpio *hlwd =
gpiochip_get_data(irq_data_get_irq_chip_data(data));
iowrite32be(BIT(data->hwirq), hlwd->regs + HW_GPIOB_INTFLAG);
}
static void hlwd_gpio_irq_mask(struct irq_data *data)
{
struct hlwd_gpio *hlwd =
gpiochip_get_data(irq_data_get_irq_chip_data(data));
unsigned long flags;
u32 mask;
spin_lock_irqsave(&hlwd->gpioc.bgpio_lock, flags);
mask = ioread32be(hlwd->regs + HW_GPIOB_INTMASK);
mask &= ~BIT(data->hwirq);
iowrite32be(mask, hlwd->regs + HW_GPIOB_INTMASK);
spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags);
}
static void hlwd_gpio_irq_unmask(struct irq_data *data)
{
struct hlwd_gpio *hlwd =
gpiochip_get_data(irq_data_get_irq_chip_data(data));
unsigned long flags;
u32 mask;
spin_lock_irqsave(&hlwd->gpioc.bgpio_lock, flags);
mask = ioread32be(hlwd->regs + HW_GPIOB_INTMASK);
mask |= BIT(data->hwirq);
iowrite32be(mask, hlwd->regs + HW_GPIOB_INTMASK);
spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags);
}
static void hlwd_gpio_irq_enable(struct irq_data *data)
{
hlwd_gpio_irq_ack(data);
hlwd_gpio_irq_unmask(data);
}
static void hlwd_gpio_irq_setup_emulation(struct hlwd_gpio *hlwd, int hwirq,
unsigned int flow_type)
{
u32 level, state;
/* Set the trigger level to the inactive level */
level = ioread32be(hlwd->regs + HW_GPIOB_INTLVL);
state = ioread32be(hlwd->regs + HW_GPIOB_IN) & BIT(hwirq);
level &= ~BIT(hwirq);
level |= state ^ BIT(hwirq);
iowrite32be(level, hlwd->regs + HW_GPIOB_INTLVL);
hlwd->edge_emulation |= BIT(hwirq);
hlwd->rising_edge &= ~BIT(hwirq);
hlwd->falling_edge &= ~BIT(hwirq);
if (flow_type & IRQ_TYPE_EDGE_RISING)
hlwd->rising_edge |= BIT(hwirq);
if (flow_type & IRQ_TYPE_EDGE_FALLING)
hlwd->falling_edge |= BIT(hwirq);
}
static int hlwd_gpio_irq_set_type(struct irq_data *data, unsigned int flow_type)
{
struct hlwd_gpio *hlwd =
gpiochip_get_data(irq_data_get_irq_chip_data(data));
unsigned long flags;
u32 level;
spin_lock_irqsave(&hlwd->gpioc.bgpio_lock, flags);
hlwd->edge_emulation &= ~BIT(data->hwirq);
switch (flow_type) {
case IRQ_TYPE_LEVEL_HIGH:
level = ioread32be(hlwd->regs + HW_GPIOB_INTLVL);
level |= BIT(data->hwirq);
iowrite32be(level, hlwd->regs + HW_GPIOB_INTLVL);
break;
case IRQ_TYPE_LEVEL_LOW:
level = ioread32be(hlwd->regs + HW_GPIOB_INTLVL);
level &= ~BIT(data->hwirq);
iowrite32be(level, hlwd->regs + HW_GPIOB_INTLVL);
break;
case IRQ_TYPE_EDGE_RISING:
case IRQ_TYPE_EDGE_FALLING:
case IRQ_TYPE_EDGE_BOTH:
hlwd_gpio_irq_setup_emulation(hlwd, data->hwirq, flow_type);
break;
default:
spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags);
return -EINVAL;
}
spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags);
return 0;
}
static int hlwd_gpio_probe(struct platform_device *pdev)
{
struct hlwd_gpio *hlwd;
u32 ngpios;
int res;
hlwd = devm_kzalloc(&pdev->dev, sizeof(*hlwd), GFP_KERNEL);
if (!hlwd)
return -ENOMEM;
hlwd->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(hlwd->regs))
return PTR_ERR(hlwd->regs);
/*
* Claim all GPIOs using the OWNER register. This will not work on
* systems where the AHBPROT memory firewall hasn't been configured to
* permit PPC access to HW_GPIO_*.
*
* Note that this has to happen before bgpio_init reads the
* HW_GPIOB_OUT and HW_GPIOB_DIR, because otherwise it reads the wrong
* values.
*/
iowrite32be(0xffffffff, hlwd->regs + HW_GPIO_OWNER);
res = bgpio_init(&hlwd->gpioc, &pdev->dev, 4,
hlwd->regs + HW_GPIOB_IN, hlwd->regs + HW_GPIOB_OUT,
NULL, hlwd->regs + HW_GPIOB_DIR, NULL,
BGPIOF_BIG_ENDIAN_BYTE_ORDER);
if (res < 0) {
dev_warn(&pdev->dev, "bgpio_init failed: %d\n", res);
return res;
}
res = of_property_read_u32(pdev->dev.of_node, "ngpios", &ngpios);
if (res)
ngpios = 32;
hlwd->gpioc.ngpio = ngpios;
res = devm_gpiochip_add_data(&pdev->dev, &hlwd->gpioc, hlwd);
if (res)
return res;
/* Mask and ack all interrupts */
iowrite32be(0, hlwd->regs + HW_GPIOB_INTMASK);
iowrite32be(0xffffffff, hlwd->regs + HW_GPIOB_INTFLAG);
/*
* If this GPIO controller is not marked as an interrupt controller in
* the DT, return.
*/
if (!of_property_read_bool(pdev->dev.of_node, "interrupt-controller"))
return 0;
hlwd->irq = platform_get_irq(pdev, 0);
if (hlwd->irq < 0) {
dev_info(&pdev->dev, "platform_get_irq returned %d\n",
hlwd->irq);
return hlwd->irq;
}
hlwd->irqc.name = dev_name(&pdev->dev);
hlwd->irqc.irq_mask = hlwd_gpio_irq_mask;
hlwd->irqc.irq_unmask = hlwd_gpio_irq_unmask;
hlwd->irqc.irq_enable = hlwd_gpio_irq_enable;
hlwd->irqc.irq_set_type = hlwd_gpio_irq_set_type;
res = gpiochip_irqchip_add(&hlwd->gpioc, &hlwd->irqc, 0,
handle_level_irq, IRQ_TYPE_NONE);
if (res)
return res;
gpiochip_set_chained_irqchip(&hlwd->gpioc, &hlwd->irqc,
hlwd->irq, hlwd_gpio_irqhandler);
return 0;
}
static const struct of_device_id hlwd_gpio_match[] = {
{ .compatible = "nintendo,hollywood-gpio", },
{},
};
MODULE_DEVICE_TABLE(of, hlwd_gpio_match);
static struct platform_driver hlwd_gpio_driver = {
.driver = {
.name = "gpio-hlwd",
.of_match_table = hlwd_gpio_match,
},
.probe = hlwd_gpio_probe,
};
module_platform_driver(hlwd_gpio_driver);
MODULE_AUTHOR("Jonathan Neuschäfer <j.neuschaefer@gmx.net>");
MODULE_DESCRIPTION("Nintendo Wii GPIO driver");
MODULE_LICENSE("GPL");
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