| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * A64FX diag driver. |
| * Copyright (c) 2022 Fujitsu Ltd. |
| */ |
| |
| #include <linux/acpi.h> |
| #include <linux/interrupt.h> |
| #include <linux/irq.h> |
| #include <linux/module.h> |
| #include <linux/platform_device.h> |
| |
| #define A64FX_DIAG_IRQ 1 |
| #define BMC_DIAG_INTERRUPT_ENABLE 0x40 |
| #define BMC_DIAG_INTERRUPT_STATUS 0x44 |
| #define BMC_DIAG_INTERRUPT_MASK BIT(31) |
| |
| struct a64fx_diag_priv { |
| void __iomem *mmsc_reg_base; |
| int irq; |
| bool has_nmi; |
| }; |
| |
| static irqreturn_t a64fx_diag_handler_nmi(int irq, void *dev_id) |
| { |
| nmi_panic(NULL, "a64fx_diag: interrupt received\n"); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static irqreturn_t a64fx_diag_handler_irq(int irq, void *dev_id) |
| { |
| panic("a64fx_diag: interrupt received\n"); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static void a64fx_diag_interrupt_clear(struct a64fx_diag_priv *priv) |
| { |
| void __iomem *diag_status_reg_addr; |
| u32 mmsc; |
| |
| diag_status_reg_addr = priv->mmsc_reg_base + BMC_DIAG_INTERRUPT_STATUS; |
| mmsc = readl(diag_status_reg_addr); |
| if (mmsc & BMC_DIAG_INTERRUPT_MASK) |
| writel(BMC_DIAG_INTERRUPT_MASK, diag_status_reg_addr); |
| } |
| |
| static void a64fx_diag_interrupt_enable(struct a64fx_diag_priv *priv) |
| { |
| void __iomem *diag_enable_reg_addr; |
| u32 mmsc; |
| |
| diag_enable_reg_addr = priv->mmsc_reg_base + BMC_DIAG_INTERRUPT_ENABLE; |
| mmsc = readl(diag_enable_reg_addr); |
| if (!(mmsc & BMC_DIAG_INTERRUPT_MASK)) { |
| mmsc |= BMC_DIAG_INTERRUPT_MASK; |
| writel(mmsc, diag_enable_reg_addr); |
| } |
| } |
| |
| static void a64fx_diag_interrupt_disable(struct a64fx_diag_priv *priv) |
| { |
| void __iomem *diag_enable_reg_addr; |
| u32 mmsc; |
| |
| diag_enable_reg_addr = priv->mmsc_reg_base + BMC_DIAG_INTERRUPT_ENABLE; |
| mmsc = readl(diag_enable_reg_addr); |
| if (mmsc & BMC_DIAG_INTERRUPT_MASK) { |
| mmsc &= ~BMC_DIAG_INTERRUPT_MASK; |
| writel(mmsc, diag_enable_reg_addr); |
| } |
| } |
| |
| static int a64fx_diag_probe(struct platform_device *pdev) |
| { |
| struct device *dev = &pdev->dev; |
| struct a64fx_diag_priv *priv; |
| unsigned long irq_flags; |
| int ret; |
| |
| priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); |
| if (priv == NULL) |
| return -ENOMEM; |
| |
| priv->mmsc_reg_base = devm_platform_ioremap_resource(pdev, 0); |
| if (IS_ERR(priv->mmsc_reg_base)) |
| return PTR_ERR(priv->mmsc_reg_base); |
| |
| priv->irq = platform_get_irq(pdev, A64FX_DIAG_IRQ); |
| if (priv->irq < 0) |
| return priv->irq; |
| |
| platform_set_drvdata(pdev, priv); |
| |
| irq_flags = IRQF_PERCPU | IRQF_NOBALANCING | IRQF_NO_AUTOEN | |
| IRQF_NO_THREAD; |
| ret = request_nmi(priv->irq, &a64fx_diag_handler_nmi, irq_flags, |
| "a64fx_diag_nmi", NULL); |
| if (ret) { |
| ret = request_irq(priv->irq, &a64fx_diag_handler_irq, |
| irq_flags, "a64fx_diag_irq", NULL); |
| if (ret) { |
| dev_err(dev, "cannot register IRQ %d\n", ret); |
| return ret; |
| } |
| enable_irq(priv->irq); |
| } else { |
| enable_nmi(priv->irq); |
| priv->has_nmi = true; |
| } |
| |
| a64fx_diag_interrupt_clear(priv); |
| a64fx_diag_interrupt_enable(priv); |
| |
| return 0; |
| } |
| |
| static int a64fx_diag_remove(struct platform_device *pdev) |
| { |
| struct a64fx_diag_priv *priv = platform_get_drvdata(pdev); |
| |
| a64fx_diag_interrupt_disable(priv); |
| a64fx_diag_interrupt_clear(priv); |
| |
| if (priv->has_nmi) |
| free_nmi(priv->irq, NULL); |
| else |
| free_irq(priv->irq, NULL); |
| |
| return 0; |
| } |
| |
| static const struct acpi_device_id a64fx_diag_acpi_match[] = { |
| { "FUJI2007", 0 }, |
| { }, |
| }; |
| MODULE_DEVICE_TABLE(acpi, a64fx_diag_acpi_match); |
| |
| |
| static struct platform_driver a64fx_diag_driver = { |
| .driver = { |
| .name = "a64fx_diag_driver", |
| .acpi_match_table = ACPI_PTR(a64fx_diag_acpi_match), |
| }, |
| .probe = a64fx_diag_probe, |
| .remove = a64fx_diag_remove, |
| }; |
| |
| module_platform_driver(a64fx_diag_driver); |
| |
| MODULE_AUTHOR("Hitomi Hasegawa <hasegawa-hitomi@fujitsu.com>"); |
| MODULE_DESCRIPTION("A64FX diag driver"); |