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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * AMD Promontory GPIO driver4 *5 * Copyright (C) 2015 ASMedia Technology Inc.6 * Author: YD Tseng <yd_tseng@asmedia.com.tw>7 */8 9#include <linux/kernel.h>10#include <linux/module.h>11#include <linux/gpio/driver.h>12#include <linux/spinlock.h>13#include <linux/acpi.h>14#include <linux/platform_device.h>15 16#define PT_TOTAL_GPIO 817#define PT_TOTAL_GPIO_EX 2418 19/* PCI-E MMIO register offsets */20#define PT_DIRECTION_REG 0x0021#define PT_INPUTDATA_REG 0x0422#define PT_OUTPUTDATA_REG 0x0823#define PT_CLOCKRATE_REG 0x0C24#define PT_SYNC_REG 0x2825 26struct pt_gpio_chip {27 struct gpio_chip gc;28 void __iomem *reg_base;29};30 31static int pt_gpio_request(struct gpio_chip *gc, unsigned offset)32{33 struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc);34 unsigned long flags;35 u32 using_pins;36 37 dev_dbg(gc->parent, "pt_gpio_request offset=%x\n", offset);38 39 raw_spin_lock_irqsave(&gc->bgpio_lock, flags);40 41 using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG);42 if (using_pins & BIT(offset)) {43 dev_warn(gc->parent, "PT GPIO pin %x reconfigured\n",44 offset);45 raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);46 return -EINVAL;47 }48 49 writel(using_pins | BIT(offset), pt_gpio->reg_base + PT_SYNC_REG);50 51 raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);52 53 return 0;54}55 56static void pt_gpio_free(struct gpio_chip *gc, unsigned offset)57{58 struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc);59 unsigned long flags;60 u32 using_pins;61 62 raw_spin_lock_irqsave(&gc->bgpio_lock, flags);63 64 using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG);65 using_pins &= ~BIT(offset);66 writel(using_pins, pt_gpio->reg_base + PT_SYNC_REG);67 68 raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);69 70 dev_dbg(gc->parent, "pt_gpio_free offset=%x\n", offset);71}72 73static int pt_gpio_probe(struct platform_device *pdev)74{75 struct device *dev = &pdev->dev;76 struct pt_gpio_chip *pt_gpio;77 int ret = 0;78 79 if (!ACPI_COMPANION(dev)) {80 dev_err(dev, "PT GPIO device node not found\n");81 return -ENODEV;82 }83 84 pt_gpio = devm_kzalloc(dev, sizeof(struct pt_gpio_chip), GFP_KERNEL);85 if (!pt_gpio)86 return -ENOMEM;87 88 pt_gpio->reg_base = devm_platform_ioremap_resource(pdev, 0);89 if (IS_ERR(pt_gpio->reg_base)) {90 dev_err(dev, "Failed to map MMIO resource for PT GPIO.\n");91 return PTR_ERR(pt_gpio->reg_base);92 }93 94 ret = bgpio_init(&pt_gpio->gc, dev, 4,95 pt_gpio->reg_base + PT_INPUTDATA_REG,96 pt_gpio->reg_base + PT_OUTPUTDATA_REG, NULL,97 pt_gpio->reg_base + PT_DIRECTION_REG, NULL,98 BGPIOF_READ_OUTPUT_REG_SET);99 if (ret) {100 dev_err(dev, "bgpio_init failed\n");101 return ret;102 }103 104 pt_gpio->gc.owner = THIS_MODULE;105 pt_gpio->gc.request = pt_gpio_request;106 pt_gpio->gc.free = pt_gpio_free;107 pt_gpio->gc.ngpio = (uintptr_t)device_get_match_data(dev);108 109 ret = gpiochip_add_data(&pt_gpio->gc, pt_gpio);110 if (ret) {111 dev_err(dev, "Failed to register GPIO lib\n");112 return ret;113 }114 115 platform_set_drvdata(pdev, pt_gpio);116 117 /* initialize register setting */118 writel(0, pt_gpio->reg_base + PT_SYNC_REG);119 writel(0, pt_gpio->reg_base + PT_CLOCKRATE_REG);120 121 dev_dbg(dev, "PT GPIO driver loaded\n");122 return ret;123}124 125static void pt_gpio_remove(struct platform_device *pdev)126{127 struct pt_gpio_chip *pt_gpio = platform_get_drvdata(pdev);128 129 gpiochip_remove(&pt_gpio->gc);130}131 132static const struct acpi_device_id pt_gpio_acpi_match[] = {133 { "AMDF030", PT_TOTAL_GPIO },134 { "AMDIF030", PT_TOTAL_GPIO },135 { "AMDIF031", PT_TOTAL_GPIO_EX },136 { },137};138MODULE_DEVICE_TABLE(acpi, pt_gpio_acpi_match);139 140static struct platform_driver pt_gpio_driver = {141 .driver = {142 .name = "pt-gpio",143 .acpi_match_table = ACPI_PTR(pt_gpio_acpi_match),144 },145 .probe = pt_gpio_probe,146 .remove_new = pt_gpio_remove,147};148 149module_platform_driver(pt_gpio_driver);150 151MODULE_LICENSE("GPL");152MODULE_AUTHOR("YD Tseng <yd_tseng@asmedia.com.tw>");153MODULE_DESCRIPTION("AMD Promontory GPIO Driver");154