156 lines
3.8 KiB
C
156 lines
3.8 KiB
C
// 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 <yd_tseng@asmedia.com.tw>
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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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#define PT_TOTAL_GPIO_EX 24
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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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raw_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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raw_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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raw_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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raw_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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raw_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 pt_gpio_chip *pt_gpio;
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int ret = 0;
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if (!ACPI_COMPANION(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 = (uintptr_t)device_get_match_data(dev);
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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", PT_TOTAL_GPIO },
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{ "AMDIF030", PT_TOTAL_GPIO },
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{ "AMDIF031", PT_TOTAL_GPIO_EX },
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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 <yd_tseng@asmedia.com.tw>");
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MODULE_DESCRIPTION("AMD Promontory GPIO Driver");
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