From patchwork Thu Feb 6 16:55:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Simon Glass X-Patchwork-Id: 236033 List-Id: U-Boot discussion From: sjg at chromium.org (Simon Glass) Date: Thu, 6 Feb 2020 09:55:01 -0700 Subject: [PATCH v4 13/17] x86: Add support for ACPI general-purpose events In-Reply-To: <20200206165505.113435-1-sjg@chromium.org> References: <20200206165505.113435-1-sjg@chromium.org> Message-ID: <20200206165505.113435-14-sjg@chromium.org> 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 Reviewed-by: Bin Meng --- Changes in v4: None Changes in v3: None 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 b3fbf306f7..c8eae24c07 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -923,4 +923,37 @@ 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 + */ + +#include +#include +#include +#include + +/** + * 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) +- reg : The register bank for the controller (set this to the ACPI base). + +Example: + + general-purpose-events { + reg = ; + 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>; + };