116 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			116 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0+
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// Copyright (C) 2008-2009 The GameCube Linux Team
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// Copyright (C) 2008,2009 Albert Herranz
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// Copyright (C) 2017-2018 Jonathan Neuschäfer
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//
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// Nintendo Wii (Hollywood) GPIO driver
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#include <linux/gpio/driver.h>
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#include <linux/io.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/of_platform.h>
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#include <linux/slab.h>
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/*
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 * Register names and offsets courtesy of WiiBrew:
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 * https://wiibrew.org/wiki/Hardware/Hollywood_GPIOs
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 *
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 * Note that for most registers, there are two versions:
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 * - HW_GPIOB_* Is always accessible by the Broadway PowerPC core, but does
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 *   always give access to all GPIO lines
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 * - HW_GPIO_* Is only accessible by the Broadway PowerPC code if the memory
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 *   firewall (AHBPROT) in the Hollywood chipset has been configured to allow
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 *   such access.
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 *
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 * The ownership of each GPIO line can be configured in the HW_GPIO_OWNER
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 * register: A one bit configures the line for access via the HW_GPIOB_*
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 * registers, a zero bit indicates access via HW_GPIO_*. This driver uses
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 * HW_GPIOB_*.
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 */
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#define HW_GPIOB_OUT		0x00
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#define HW_GPIOB_DIR		0x04
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#define HW_GPIOB_IN		0x08
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#define HW_GPIOB_INTLVL		0x0c
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#define HW_GPIOB_INTFLAG	0x10
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#define HW_GPIOB_INTMASK	0x14
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#define HW_GPIOB_INMIR		0x18
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#define HW_GPIO_ENABLE		0x1c
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#define HW_GPIO_OUT		0x20
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#define HW_GPIO_DIR		0x24
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#define HW_GPIO_IN		0x28
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#define HW_GPIO_INTLVL		0x2c
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#define HW_GPIO_INTFLAG		0x30
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#define HW_GPIO_INTMASK		0x34
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#define HW_GPIO_INMIR		0x38
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#define HW_GPIO_OWNER		0x3c
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struct hlwd_gpio {
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	struct gpio_chip gpioc;
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	void __iomem *regs;
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};
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static int hlwd_gpio_probe(struct platform_device *pdev)
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{
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	struct hlwd_gpio *hlwd;
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	struct resource *regs_resource;
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	u32 ngpios;
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	int res;
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	hlwd = devm_kzalloc(&pdev->dev, sizeof(*hlwd), GFP_KERNEL);
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	if (!hlwd)
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		return -ENOMEM;
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	regs_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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	hlwd->regs = devm_ioremap_resource(&pdev->dev, regs_resource);
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	if (IS_ERR(hlwd->regs))
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		return PTR_ERR(hlwd->regs);
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	/*
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	 * Claim all GPIOs using the OWNER register. This will not work on
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	 * systems where the AHBPROT memory firewall hasn't been configured to
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	 * permit PPC access to HW_GPIO_*.
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	 *
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	 * Note that this has to happen before bgpio_init reads the
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	 * HW_GPIOB_OUT and HW_GPIOB_DIR, because otherwise it reads the wrong
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	 * values.
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	 */
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	iowrite32be(0xffffffff, hlwd->regs + HW_GPIO_OWNER);
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	res = bgpio_init(&hlwd->gpioc, &pdev->dev, 4,
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			hlwd->regs + HW_GPIOB_IN, hlwd->regs + HW_GPIOB_OUT,
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			NULL, hlwd->regs + HW_GPIOB_DIR, NULL,
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			BGPIOF_BIG_ENDIAN_BYTE_ORDER);
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	if (res < 0) {
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		dev_warn(&pdev->dev, "bgpio_init failed: %d\n", res);
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		return res;
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	}
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	res = of_property_read_u32(pdev->dev.of_node, "ngpios", &ngpios);
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	if (res)
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		ngpios = 32;
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	hlwd->gpioc.ngpio = ngpios;
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	return devm_gpiochip_add_data(&pdev->dev, &hlwd->gpioc, hlwd);
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}
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static const struct of_device_id hlwd_gpio_match[] = {
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	{ .compatible = "nintendo,hollywood-gpio", },
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	{},
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};
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MODULE_DEVICE_TABLE(of, hlwd_gpio_match);
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static struct platform_driver hlwd_gpio_driver = {
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	.driver	= {
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		.name		= "gpio-hlwd",
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		.of_match_table	= hlwd_gpio_match,
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	},
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	.probe	= hlwd_gpio_probe,
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};
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module_platform_driver(hlwd_gpio_driver);
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MODULE_AUTHOR("Jonathan Neuschäfer <j.neuschaefer@gmx.net>");
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MODULE_DESCRIPTION("Nintendo Wii GPIO driver");
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MODULE_LICENSE("GPL");
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