diff options
Diffstat (limited to 'drivers/gpio/gpio-hlwd.c')
| -rw-r--r-- | drivers/gpio/gpio-hlwd.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-hlwd.c b/drivers/gpio/gpio-hlwd.c new file mode 100644 index 000000000000..a63136a68ba3 --- /dev/null +++ b/drivers/gpio/gpio-hlwd.c @@ -0,0 +1,115 @@ +// 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"); |