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157 lines
3.9 KiB
157 lines
3.9 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* AMD Promontory GPIO driver |
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* |
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* Copyright (C) 2015 ASMedia Technology Inc. |
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* Author: YD Tseng <[email protected]> |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/gpio/driver.h> |
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#include <linux/spinlock.h> |
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#include <linux/acpi.h> |
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#include <linux/platform_device.h> |
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#define PT_TOTAL_GPIO 8 |
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/* PCI-E MMIO register offsets */ |
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#define PT_DIRECTION_REG 0x00 |
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#define PT_INPUTDATA_REG 0x04 |
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#define PT_OUTPUTDATA_REG 0x08 |
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#define PT_CLOCKRATE_REG 0x0C |
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#define PT_SYNC_REG 0x28 |
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struct pt_gpio_chip { |
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struct gpio_chip gc; |
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void __iomem *reg_base; |
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}; |
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static int pt_gpio_request(struct gpio_chip *gc, unsigned offset) |
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{ |
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struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc); |
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unsigned long flags; |
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u32 using_pins; |
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dev_dbg(gc->parent, "pt_gpio_request offset=%x\n", offset); |
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spin_lock_irqsave(&gc->bgpio_lock, flags); |
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using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG); |
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if (using_pins & BIT(offset)) { |
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dev_warn(gc->parent, "PT GPIO pin %x reconfigured\n", |
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offset); |
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spin_unlock_irqrestore(&gc->bgpio_lock, flags); |
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return -EINVAL; |
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} |
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writel(using_pins | BIT(offset), pt_gpio->reg_base + PT_SYNC_REG); |
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spin_unlock_irqrestore(&gc->bgpio_lock, flags); |
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return 0; |
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} |
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static void pt_gpio_free(struct gpio_chip *gc, unsigned offset) |
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{ |
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struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc); |
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unsigned long flags; |
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u32 using_pins; |
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spin_lock_irqsave(&gc->bgpio_lock, flags); |
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using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG); |
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using_pins &= ~BIT(offset); |
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writel(using_pins, pt_gpio->reg_base + PT_SYNC_REG); |
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spin_unlock_irqrestore(&gc->bgpio_lock, flags); |
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dev_dbg(gc->parent, "pt_gpio_free offset=%x\n", offset); |
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} |
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static int pt_gpio_probe(struct platform_device *pdev) |
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{ |
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struct device *dev = &pdev->dev; |
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struct acpi_device *acpi_dev; |
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acpi_handle handle = ACPI_HANDLE(dev); |
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struct pt_gpio_chip *pt_gpio; |
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int ret = 0; |
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if (acpi_bus_get_device(handle, &acpi_dev)) { |
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dev_err(dev, "PT GPIO device node not found\n"); |
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return -ENODEV; |
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} |
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pt_gpio = devm_kzalloc(dev, sizeof(struct pt_gpio_chip), GFP_KERNEL); |
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if (!pt_gpio) |
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return -ENOMEM; |
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pt_gpio->reg_base = devm_platform_ioremap_resource(pdev, 0); |
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if (IS_ERR(pt_gpio->reg_base)) { |
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dev_err(dev, "Failed to map MMIO resource for PT GPIO.\n"); |
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return PTR_ERR(pt_gpio->reg_base); |
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} |
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ret = bgpio_init(&pt_gpio->gc, dev, 4, |
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pt_gpio->reg_base + PT_INPUTDATA_REG, |
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pt_gpio->reg_base + PT_OUTPUTDATA_REG, NULL, |
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pt_gpio->reg_base + PT_DIRECTION_REG, NULL, |
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BGPIOF_READ_OUTPUT_REG_SET); |
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if (ret) { |
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dev_err(dev, "bgpio_init failed\n"); |
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return ret; |
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} |
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pt_gpio->gc.owner = THIS_MODULE; |
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pt_gpio->gc.request = pt_gpio_request; |
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pt_gpio->gc.free = pt_gpio_free; |
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pt_gpio->gc.ngpio = PT_TOTAL_GPIO; |
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#if defined(CONFIG_OF_GPIO) |
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pt_gpio->gc.of_node = dev->of_node; |
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#endif |
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ret = gpiochip_add_data(&pt_gpio->gc, pt_gpio); |
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if (ret) { |
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dev_err(dev, "Failed to register GPIO lib\n"); |
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return ret; |
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} |
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platform_set_drvdata(pdev, pt_gpio); |
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/* initialize register setting */ |
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writel(0, pt_gpio->reg_base + PT_SYNC_REG); |
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writel(0, pt_gpio->reg_base + PT_CLOCKRATE_REG); |
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dev_dbg(dev, "PT GPIO driver loaded\n"); |
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return ret; |
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} |
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static int pt_gpio_remove(struct platform_device *pdev) |
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{ |
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struct pt_gpio_chip *pt_gpio = platform_get_drvdata(pdev); |
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gpiochip_remove(&pt_gpio->gc); |
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return 0; |
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} |
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static const struct acpi_device_id pt_gpio_acpi_match[] = { |
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{ "AMDF030", 0 }, |
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{ "AMDIF030", 0 }, |
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{ }, |
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}; |
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MODULE_DEVICE_TABLE(acpi, pt_gpio_acpi_match); |
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static struct platform_driver pt_gpio_driver = { |
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.driver = { |
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.name = "pt-gpio", |
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.acpi_match_table = ACPI_PTR(pt_gpio_acpi_match), |
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}, |
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.probe = pt_gpio_probe, |
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.remove = pt_gpio_remove, |
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}; |
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module_platform_driver(pt_gpio_driver); |
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MODULE_LICENSE("GPL"); |
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MODULE_AUTHOR("YD Tseng <[email protected]>"); |
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MODULE_DESCRIPTION("AMD Promontory GPIO Driver");
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