mirror_ubuntu-kernels/drivers/soc/fujitsu/a64fx-diag.c

152 lines
3.6 KiB
C

// 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 void 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);
}
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_new = a64fx_diag_remove,
};
module_platform_driver(a64fx_diag_driver);
MODULE_AUTHOR("Hitomi Hasegawa <hasegawa-hitomi@fujitsu.com>");
MODULE_DESCRIPTION("A64FX diag driver");