// SPDX-License-Identifier: GPL-2.0-only /* * AMD Promontory GPIO driver * * Copyright (C) 2015 ASMedia Technology Inc. * Author: YD Tseng <yd_tseng@asmedia.com.tw> */ #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 #define PT_TOTAL_GPIO_EX 24 /* 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); raw_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); raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags); return -EINVAL; } writel(using_pins | BIT(offset), pt_gpio->reg_base + PT_SYNC_REG); raw_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; raw_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); raw_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 pt_gpio_chip *pt_gpio; int ret = 0; if (!ACPI_COMPANION(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; pt_gpio->reg_base = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(pt_gpio->reg_base)) { dev_err(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(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 = (uintptr_t)device_get_match_data(dev); ret = gpiochip_add_data(&pt_gpio->gc, pt_gpio); if (ret) { dev_err(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(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", PT_TOTAL_GPIO }, { "AMDIF030", PT_TOTAL_GPIO }, { "AMDIF031", PT_TOTAL_GPIO_EX }, { }, }; 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");