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- // SPDX-License-Identifier: GPL-2.0-only
- /*
- * AMD Promontory GPIO driver
- *
- * Copyright (C) 2015 ASMedia Technology Inc.
- * Author: YD Tseng <[email protected]>
- */
- #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 <[email protected]>");
- MODULE_DESCRIPTION("AMD Promontory GPIO Driver");
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