u-boot/arch/x86/cpu/acpi_gpe.c
Simon Glass e85cbe8b34 x86: Add support for ACPI general-purpose events
ACPI GPEs are used to signal interrupts from peripherals that are accessed
via ACPI. In U-Boot these are modelled as interrupts using a separate
interrupt controller. Configuration is via the device tree.

Add a simple driver for this.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-02-07 22:46:35 +08:00

85 lines
1.7 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright 2019 Google, LLC
* Written by Simon Glass <sjg@chromium.org>
*/
#include <common.h>
#include <dm.h>
#include <irq.h>
#include <asm/io.h>
/**
* struct acpi_gpe_priv - private driver information
*
* @acpi_base: Base I/O address of ACPI registers
*/
struct acpi_gpe_priv {
ulong acpi_base;
};
#define GPE0_STS(x) (0x20 + ((x) * 4))
static int acpi_gpe_read_and_clear(struct irq *irq)
{
struct acpi_gpe_priv *priv = dev_get_priv(irq->dev);
u32 mask, sts;
ulong start;
int ret = 0;
int bank;
bank = irq->id / 32;
mask = 1 << (irq->id % 32);
/* Wait up to 1ms for GPE status to clear */
start = get_timer(0);
do {
if (get_timer(start) > 1)
return ret;
sts = inl(priv->acpi_base + GPE0_STS(bank));
if (sts & mask) {
outl(mask, priv->acpi_base + GPE0_STS(bank));
ret = 1;
}
} while (sts & mask);
return ret;
}
static int acpi_gpe_ofdata_to_platdata(struct udevice *dev)
{
struct acpi_gpe_priv *priv = dev_get_priv(dev);
priv->acpi_base = dev_read_addr(dev);
if (!priv->acpi_base || priv->acpi_base == FDT_ADDR_T_NONE)
return log_msg_ret("acpi_base", -EINVAL);
return 0;
}
static int acpi_gpe_of_xlate(struct irq *irq, struct ofnode_phandle_args *args)
{
irq->id = args->args[0];
return 0;
}
static const struct irq_ops acpi_gpe_ops = {
.read_and_clear = acpi_gpe_read_and_clear,
.of_xlate = acpi_gpe_of_xlate,
};
static const struct udevice_id acpi_gpe_ids[] = {
{ .compatible = "intel,acpi-gpe", .data = X86_IRQT_ACPI_GPE },
{ }
};
U_BOOT_DRIVER(acpi_gpe_drv) = {
.name = "acpi_gpe",
.id = UCLASS_IRQ,
.of_match = acpi_gpe_ids,
.ops = &acpi_gpe_ops,
.ofdata_to_platdata = acpi_gpe_ofdata_to_platdata,
.priv_auto_alloc_size = sizeof(struct acpi_gpe_priv),
};