linux/drivers/gpio/gpio-hlwd.c

116 lines
3.3 KiB
C

// 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;
void __iomem *regs;
};
static int hlwd_gpio_probe(struct platform_device *pdev)
{
struct hlwd_gpio *hlwd;
struct resource *regs_resource;
u32 ngpios;
int res;
hlwd = devm_kzalloc(&pdev->dev, sizeof(*hlwd), GFP_KERNEL);
if (!hlwd)
return -ENOMEM;
regs_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
hlwd->regs = devm_ioremap_resource(&pdev->dev, regs_resource);
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;
return devm_gpiochip_add_data(&pdev->dev, &hlwd->gpioc, hlwd);
}
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");