1 // SPDX-License-Identifier: GPL-2.0+ 2 // Copyright (C) 2008-2009 The GameCube Linux Team 3 // Copyright (C) 2008,2009 Albert Herranz 4 // Copyright (C) 2017-2018 Jonathan Neuschäfer 5 // 6 // Nintendo Wii (Hollywood) GPIO driver 7 8 #include <linux/gpio/driver.h> 9 #include <linux/io.h> 10 #include <linux/kernel.h> 11 #include <linux/module.h> 12 #include <linux/of.h> 13 #include <linux/of_platform.h> 14 #include <linux/slab.h> 15 16 /* 17 * Register names and offsets courtesy of WiiBrew: 18 * https://wiibrew.org/wiki/Hardware/Hollywood_GPIOs 19 * 20 * Note that for most registers, there are two versions: 21 * - HW_GPIOB_* Is always accessible by the Broadway PowerPC core, but does 22 * always give access to all GPIO lines 23 * - HW_GPIO_* Is only accessible by the Broadway PowerPC code if the memory 24 * firewall (AHBPROT) in the Hollywood chipset has been configured to allow 25 * such access. 26 * 27 * The ownership of each GPIO line can be configured in the HW_GPIO_OWNER 28 * register: A one bit configures the line for access via the HW_GPIOB_* 29 * registers, a zero bit indicates access via HW_GPIO_*. This driver uses 30 * HW_GPIOB_*. 31 */ 32 #define HW_GPIOB_OUT 0x00 33 #define HW_GPIOB_DIR 0x04 34 #define HW_GPIOB_IN 0x08 35 #define HW_GPIOB_INTLVL 0x0c 36 #define HW_GPIOB_INTFLAG 0x10 37 #define HW_GPIOB_INTMASK 0x14 38 #define HW_GPIOB_INMIR 0x18 39 #define HW_GPIO_ENABLE 0x1c 40 #define HW_GPIO_OUT 0x20 41 #define HW_GPIO_DIR 0x24 42 #define HW_GPIO_IN 0x28 43 #define HW_GPIO_INTLVL 0x2c 44 #define HW_GPIO_INTFLAG 0x30 45 #define HW_GPIO_INTMASK 0x34 46 #define HW_GPIO_INMIR 0x38 47 #define HW_GPIO_OWNER 0x3c 48 49 struct hlwd_gpio { 50 struct gpio_chip gpioc; 51 void __iomem *regs; 52 }; 53 54 static int hlwd_gpio_probe(struct platform_device *pdev) 55 { 56 struct hlwd_gpio *hlwd; 57 struct resource *regs_resource; 58 u32 ngpios; 59 int res; 60 61 hlwd = devm_kzalloc(&pdev->dev, sizeof(*hlwd), GFP_KERNEL); 62 if (!hlwd) 63 return -ENOMEM; 64 65 regs_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0); 66 hlwd->regs = devm_ioremap_resource(&pdev->dev, regs_resource); 67 if (IS_ERR(hlwd->regs)) 68 return PTR_ERR(hlwd->regs); 69 70 /* 71 * Claim all GPIOs using the OWNER register. This will not work on 72 * systems where the AHBPROT memory firewall hasn't been configured to 73 * permit PPC access to HW_GPIO_*. 74 * 75 * Note that this has to happen before bgpio_init reads the 76 * HW_GPIOB_OUT and HW_GPIOB_DIR, because otherwise it reads the wrong 77 * values. 78 */ 79 iowrite32be(0xffffffff, hlwd->regs + HW_GPIO_OWNER); 80 81 res = bgpio_init(&hlwd->gpioc, &pdev->dev, 4, 82 hlwd->regs + HW_GPIOB_IN, hlwd->regs + HW_GPIOB_OUT, 83 NULL, hlwd->regs + HW_GPIOB_DIR, NULL, 84 BGPIOF_BIG_ENDIAN_BYTE_ORDER); 85 if (res < 0) { 86 dev_warn(&pdev->dev, "bgpio_init failed: %d\n", res); 87 return res; 88 } 89 90 res = of_property_read_u32(pdev->dev.of_node, "ngpios", &ngpios); 91 if (res) 92 ngpios = 32; 93 hlwd->gpioc.ngpio = ngpios; 94 95 return devm_gpiochip_add_data(&pdev->dev, &hlwd->gpioc, hlwd); 96 } 97 98 static const struct of_device_id hlwd_gpio_match[] = { 99 { .compatible = "nintendo,hollywood-gpio", }, 100 {}, 101 }; 102 MODULE_DEVICE_TABLE(of, hlwd_gpio_match); 103 104 static struct platform_driver hlwd_gpio_driver = { 105 .driver = { 106 .name = "gpio-hlwd", 107 .of_match_table = hlwd_gpio_match, 108 }, 109 .probe = hlwd_gpio_probe, 110 }; 111 module_platform_driver(hlwd_gpio_driver); 112 113 MODULE_AUTHOR("Jonathan Neuschäfer <j.neuschaefer@gmx.net>"); 114 MODULE_DESCRIPTION("Nintendo Wii GPIO driver"); 115 MODULE_LICENSE("GPL"); 116