[PATCH v2 13/17] x86: Add support for ACPI general-purpose events
Bin Meng
bmeng.cn at gmail.com
Tue Feb 4 10:08:07 CET 2020
On Tue, Feb 4, 2020 at 8:20 AM Simon Glass <sjg at chromium.org> wrote:
>
> 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 at chromium.org>
> ---
>
> Changes in v2: None
>
> arch/x86/Kconfig | 33 +++++++
> arch/x86/cpu/Makefile | 1 +
> arch/x86/cpu/acpi_gpe.c | 85 +++++++++++++++++++
> .../interrupt-controller/intel,acpi-gpe.txt | 30 +++++++
> 4 files changed, 149 insertions(+)
> create mode 100644 arch/x86/cpu/acpi_gpe.c
> create mode 100644 doc/device-tree-bindings/interrupt-controller/intel,acpi-gpe.txt
>
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 89b93e5de2..c4a9a9f624 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -910,4 +910,37 @@ config X86_OFFSET_SPL
> depends on SPL && X86
> default SPL_TEXT_BASE
>
> +config ACPI_GPE
> + bool "Support ACPI general-purpose events"
> + help
> + Enable a driver for ACPI GPEs to allow peripherals to send interrupts
> + via ACPI to the OS. In U-Boot this is only used when U-Boot itself
> + needs access to these interrupts. This can happen when it uses a
> + peripheral that is set up to use GPEs and so cannot use the normal
> + GPIO mechanism for polling an input.
> +
> + See https://queue.acm.org/blogposting.cfm?id=18977 for more info
> +
> +config SPL_ACPI_GPE
> + bool "Support ACPI general-purpose events in SPL"
> + help
> + Enable a driver for ACPI GPEs to allow peripherals to send interrupts
> + via ACPI to the OS. In U-Boot this is only used when U-Boot itself
> + needs access to these interrupts. This can happen when it uses a
> + peripheral that is set up to use GPEs and so cannot use the normal
> + GPIO mechanism for polling an input.
> +
> + See https://queue.acm.org/blogposting.cfm?id=18977 for more info
> +
> +config TPL_ACPI_GPE
> + bool "Support ACPI general-purpose events in TPL"
> + help
> + Enable a driver for ACPI GPEs to allow peripherals to send interrupts
> + via ACPI to the OS. In U-Boot this is only used when U-Boot itself
> + needs access to these interrupts. This can happen when it uses a
> + peripheral that is set up to use GPEs and so cannot use the normal
> + GPIO mechanism for polling an input.
> +
> + See https://queue.acm.org/blogposting.cfm?id=18977 for more info
> +
> endmenu
> diff --git a/arch/x86/cpu/Makefile b/arch/x86/cpu/Makefile
> index 5b40838e60..307267a8fb 100644
> --- a/arch/x86/cpu/Makefile
> +++ b/arch/x86/cpu/Makefile
> @@ -55,6 +55,7 @@ obj-$(CONFIG_INTEL_QUEENSBAY) += queensbay/
> obj-$(CONFIG_INTEL_TANGIER) += tangier/
> obj-$(CONFIG_APIC) += lapic.o ioapic.o
> obj-$(CONFIG_$(SPL_TPL_)X86_32BIT_INIT) += irq.o
> +obj-$(CONFIG_$(SPL_TPL_)ACPI_GPE) += acpi_gpe.o
> obj-$(CONFIG_QFW) += qfw_cpu.o
> ifndef CONFIG_$(SPL_)X86_64
> obj-$(CONFIG_SMP) += mp_init.o
> diff --git a/arch/x86/cpu/acpi_gpe.c b/arch/x86/cpu/acpi_gpe.c
> new file mode 100644
> index 0000000000..55005455c0
> --- /dev/null
> +++ b/arch/x86/cpu/acpi_gpe.c
> @@ -0,0 +1,85 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright 2019 Google, LLC
> + * Written by Simon Glass <sjg at 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),
> +};
> diff --git a/doc/device-tree-bindings/interrupt-controller/intel,acpi-gpe.txt b/doc/device-tree-bindings/interrupt-controller/intel,acpi-gpe.txt
> new file mode 100644
> index 0000000000..d9252bf29f
> --- /dev/null
> +++ b/doc/device-tree-bindings/interrupt-controller/intel,acpi-gpe.txt
> @@ -0,0 +1,30 @@
> +* Intel Advanced Configuration and Power Interface General Purpose Events
> +
> +This describes an interrupt controller which provides access to GPEs supported
> +by the SoC.
> +
> +Required properties:
> +
> +- compatible : "intel,acpi-gpe"
> +- interrupt-controller : Identifies the node as an interrupt controller
> +- #interrupt-cells : The number of cells to define the interrupts. Must be 2:
> + cell 0: interrupt number (normally >=32 since GPEs below that are reserved)
> + cell 1: 0 (flags, but none are currently defined)
I wonder why we have to use #interrupt-cells = <2> since cell 1 is always zero
> +- reg : The register bank for the controller (set this to the ACPI base).
> +
> +Example:
> +
> + general-purpose-events {
> + reg = <IOMAP_ACPI_BASE IOMAP_ACPI_SIZE>;
> + compatible = "intel,acpi-gpe";
> + interrupt-controller;
> + #interrupt-cells = <2>;
> + };
> +
> + ...
> + tpm at 50 {
> + reg = <0x50>;
> + compatible = "google,cr50";
> + ready-gpio = <&gpio_n 0x1c GPIO_ACTIVE_LOW>;
> + interrupts-extended = <&acpi_gpe 0x3c 0>;
> + };
> --
Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
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