diff options
Diffstat (limited to 'drivers/soc/fujitsu/a64fx-diag.c')
| -rw-r--r-- | drivers/soc/fujitsu/a64fx-diag.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/drivers/soc/fujitsu/a64fx-diag.c b/drivers/soc/fujitsu/a64fx-diag.c new file mode 100644 index 000000000000..d87f348427bf --- /dev/null +++ b/drivers/soc/fujitsu/a64fx-diag.c @@ -0,0 +1,154 @@ +// 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_LICENSE("GPL v2"); +MODULE_AUTHOR("Hitomi Hasegawa <hasegawa-hitomi@fujitsu.com>"); +MODULE_DESCRIPTION("A64FX diag driver"); |