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linux/drivers/soc/fujitsu/a64fx-diag.c
Uwe Kleine-König 9a9b332db0 soc/fujitsu: a64fx-diag: Convert to platform remove callback returning void
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new() which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Link: https://lore.kernel.org/r/20230925095532.1984344-9-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2023-10-14 23:27:01 +02:00

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");