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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 | /* * AMD Promontory GPIO driver * * Copyright (C) 2015 ASMedia Technology Inc. * Author: YD Tseng <yd_tseng@asmedia.com.tw> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/gpio/driver.h> #include <linux/spinlock.h> #include <linux/acpi.h> #include <linux/platform_device.h> #define PT_TOTAL_GPIO 8 /* PCI-E MMIO register offsets */ #define PT_DIRECTION_REG 0x00 #define PT_INPUTDATA_REG 0x04 #define PT_OUTPUTDATA_REG 0x08 #define PT_CLOCKRATE_REG 0x0C #define PT_SYNC_REG 0x28 struct pt_gpio_chip { struct gpio_chip gc; void __iomem *reg_base; }; static int pt_gpio_request(struct gpio_chip *gc, unsigned offset) { struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc); unsigned long flags; u32 using_pins; dev_dbg(gc->parent, "pt_gpio_request offset=%x\n", offset); spin_lock_irqsave(&gc->bgpio_lock, flags); using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG); if (using_pins & BIT(offset)) { dev_warn(gc->parent, "PT GPIO pin %x reconfigured\n", offset); spin_unlock_irqrestore(&gc->bgpio_lock, flags); return -EINVAL; } writel(using_pins | BIT(offset), pt_gpio->reg_base + PT_SYNC_REG); spin_unlock_irqrestore(&gc->bgpio_lock, flags); return 0; } static void pt_gpio_free(struct gpio_chip *gc, unsigned offset) { struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc); unsigned long flags; u32 using_pins; spin_lock_irqsave(&gc->bgpio_lock, flags); using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG); using_pins &= ~BIT(offset); writel(using_pins, pt_gpio->reg_base + PT_SYNC_REG); spin_unlock_irqrestore(&gc->bgpio_lock, flags); dev_dbg(gc->parent, "pt_gpio_free offset=%x\n", offset); } static int pt_gpio_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct acpi_device *acpi_dev; acpi_handle handle = ACPI_HANDLE(dev); struct pt_gpio_chip *pt_gpio; struct resource *res_mem; int ret = 0; if (acpi_bus_get_device(handle, &acpi_dev)) { dev_err(dev, "PT GPIO device node not found\n"); return -ENODEV; } pt_gpio = devm_kzalloc(dev, sizeof(struct pt_gpio_chip), GFP_KERNEL); if (!pt_gpio) return -ENOMEM; res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res_mem) { dev_err(&pdev->dev, "Failed to get MMIO resource for PT GPIO.\n"); return -EINVAL; } pt_gpio->reg_base = devm_ioremap_resource(dev, res_mem); if (IS_ERR(pt_gpio->reg_base)) { dev_err(&pdev->dev, "Failed to map MMIO resource for PT GPIO.\n"); return PTR_ERR(pt_gpio->reg_base); } ret = bgpio_init(&pt_gpio->gc, dev, 4, pt_gpio->reg_base + PT_INPUTDATA_REG, pt_gpio->reg_base + PT_OUTPUTDATA_REG, NULL, pt_gpio->reg_base + PT_DIRECTION_REG, NULL, BGPIOF_READ_OUTPUT_REG_SET); if (ret) { dev_err(&pdev->dev, "bgpio_init failed\n"); return ret; } pt_gpio->gc.owner = THIS_MODULE; pt_gpio->gc.request = pt_gpio_request; pt_gpio->gc.free = pt_gpio_free; pt_gpio->gc.ngpio = PT_TOTAL_GPIO; #if defined(CONFIG_OF_GPIO) pt_gpio->gc.of_node = pdev->dev.of_node; #endif ret = gpiochip_add_data(&pt_gpio->gc, pt_gpio); if (ret) { dev_err(&pdev->dev, "Failed to register GPIO lib\n"); return ret; } platform_set_drvdata(pdev, pt_gpio); /* initialize register setting */ writel(0, pt_gpio->reg_base + PT_SYNC_REG); writel(0, pt_gpio->reg_base + PT_CLOCKRATE_REG); dev_dbg(&pdev->dev, "PT GPIO driver loaded\n"); return ret; } static int pt_gpio_remove(struct platform_device *pdev) { struct pt_gpio_chip *pt_gpio = platform_get_drvdata(pdev); gpiochip_remove(&pt_gpio->gc); return 0; } static const struct acpi_device_id pt_gpio_acpi_match[] = { { "AMDF030", 0 }, { "AMDIF030", 0 }, { }, }; MODULE_DEVICE_TABLE(acpi, pt_gpio_acpi_match); static struct platform_driver pt_gpio_driver = { .driver = { .name = "pt-gpio", .acpi_match_table = ACPI_PTR(pt_gpio_acpi_match), }, .probe = pt_gpio_probe, .remove = pt_gpio_remove, }; module_platform_driver(pt_gpio_driver); MODULE_LICENSE("GPL"); MODULE_AUTHOR("YD Tseng <yd_tseng@asmedia.com.tw>"); MODULE_DESCRIPTION("AMD Promontory GPIO Driver"); |