[PATCH v3 06/35] acpi: Support generation of interrupt descriptor
Bin Meng
bmeng.cn at gmail.com
Sun Jun 28 11:55:02 CEST 2020
Hi Simon,
On Sun, Jun 14, 2020 at 10:55 AM Simon Glass <sjg at chromium.org> wrote:
>
> Add a function to write an interrupt descriptor to the generated ACPI
> code.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> Reviewed-by: Wolfgang Wallner <wolfgang.wallner at br-automation.com>
> ---
>
> (no changes since v1)
>
> include/acpi/acpi_device.h | 15 +++++
> lib/acpi/acpi_device.c | 118 +++++++++++++++++++++++++++++++++++++
> test/dm/acpigen.c | 31 ++++++++++
> 3 files changed, 164 insertions(+)
>
> diff --git a/include/acpi/acpi_device.h b/include/acpi/acpi_device.h
> index 24895de0da..4f87cd003a 100644
> --- a/include/acpi/acpi_device.h
> +++ b/include/acpi/acpi_device.h
> @@ -11,6 +11,8 @@
>
> #include <linux/bitops.h>
>
> +struct acpi_ctx;
> +struct irq;
> struct udevice;
>
> /* ACPI descriptor values for common descriptors: SERIAL_BUS means I2C */
> @@ -128,4 +130,17 @@ int acpi_device_scope(const struct udevice *dev, char *scope, int maxlen);
> */
> enum acpi_dev_status acpi_device_status(const struct udevice *dev);
>
> +/**
> + * acpi_device_write_interrupt_irq() - Write an interrupt descriptor
> + *
> + * This writes an ACPI interrupt descriptor for the given interrupt, converting
> + * fields as needed.
> + *
> + * @ctx: ACPI context pointer
> + * @req_irq: Interrupt to output
> + * @return 0 if OK, -ve on error
> + */
> +int acpi_device_write_interrupt_irq(struct acpi_ctx *ctx,
> + const struct irq *req_irq);
> +
> #endif
> diff --git a/lib/acpi/acpi_device.c b/lib/acpi/acpi_device.c
> index 60f4fd8cd5..94f37b8d73 100644
> --- a/lib/acpi/acpi_device.c
> +++ b/lib/acpi/acpi_device.c
> @@ -8,8 +8,10 @@
>
> #include <common.h>
> #include <dm.h>
> +#include <irq.h>
> #include <log.h>
> #include <acpi/acpi_device.h>
> +#include <acpi/acpigen.h>
> #include <dm/acpi.h>
>
> /**
> @@ -86,3 +88,119 @@ enum acpi_dev_status acpi_device_status(const struct udevice *dev)
> {
> return ACPI_DSTATUS_ALL_ON;
> }
> +
> +/**
> + * acpi_device_write_zero_len() - Write a placeholder word value
> + *
> + * @return pointer to the zero word (for fixing up later)
This function name seems to be generic. Are all lengths in various
ACPI objects following the same 2 bytes convention to represent
length?
Per the ACPI spec, this seems to only apply to Large Resource Data
Type, so we should probably rename this API to reflect this.
> + */
> +static void *acpi_device_write_zero_len(struct acpi_ctx *ctx)
> +{
> + u8 *p = acpigen_get_current(ctx);
> +
> + acpigen_emit_word(ctx, 0);
> +
> + return p;
> +}
> +
> +/**
> + * acpi_device_fill_from_len() - Fill in a length value
> + *
> + * This calculated the number of bytes since the provided @start and writes it
> + * to @ptr, which was previous returned by acpi_device_write_zero_len().
> + *
> + * @ptr: Word to update
> + * @start: Start address to count from to calculated the length
> + */
> +static void acpi_device_fill_from_len(struct acpi_ctx *ctx, char *ptr,
> + u8 *start)
> +{
> + u16 len = acpigen_get_current(ctx) - start;
> +
> + ptr[0] = len & 0xff;
> + ptr[1] = (len >> 8) & 0xff;
> +}
> +
> +/**
> + * acpi_device_fill_len() - Fill in a length value, excluding the length itself
> + *
> + * Fill in the length field with the value calculated from after the 16bit
> + * field to acpigen current. This is useful since the length value does not
> + * include the length field itself.
> + *
> + * This calls acpi_device_fill_from_len() passing @ptr + 2 as @start
> + *
> + * @ptr: Word to update.
> + */
> +static void acpi_device_fill_len(struct acpi_ctx *ctx, void *ptr)
> +{
> + acpi_device_fill_from_len(ctx, ptr, ptr + sizeof(u16));
> +}
> +
> +/* ACPI 6.3 section 6.4.3.6: Extended Interrupt Descriptor */
> +static int acpi_device_write_interrupt(struct acpi_ctx *ctx,
> + const struct acpi_irq *irq)
> +{
> + void *desc_length;
> + u8 flags;
> +
> + if (!irq->pin)
> + return -ENOENT;
> +
> + /* This is supported by GpioInt() but not Interrupt() */
> + if (irq->polarity == ACPI_IRQ_ACTIVE_BOTH)
> + return -EINVAL;
> +
> + /* Byte 0: Descriptor Type */
> + acpigen_emit_byte(ctx, ACPI_DESCRIPTOR_INTERRUPT);
> +
> + /* Byte 1-2: Length (filled in later) */
> + desc_length = acpi_device_write_zero_len(ctx);
> +
> + /*
> + * Byte 3: Flags
> + * [7:5]: Reserved
> + * [4]: Wake (0=NO_WAKE 1=WAKE)
> + * [3]: Sharing (0=EXCLUSIVE 1=SHARED)
> + * [2]: Polarity (0=HIGH 1=LOW)
> + * [1]: Mode (0=LEVEL 1=EDGE)
> + * [0]: Resource (0=PRODUCER 1=CONSUMER)
> + */
> + flags = BIT(0); /* ResourceConsumer */
> + if (irq->mode == ACPI_IRQ_EDGE_TRIGGERED)
> + flags |= BIT(1);
> + if (irq->polarity == ACPI_IRQ_ACTIVE_LOW)
> + flags |= BIT(2);
> + if (irq->shared == ACPI_IRQ_SHARED)
> + flags |= BIT(3);
> + if (irq->wake == ACPI_IRQ_WAKE)
> + flags |= BIT(4);
> + acpigen_emit_byte(ctx, flags);
> +
> + /* Byte 4: Interrupt Table Entry Count */
> + acpigen_emit_byte(ctx, 1);
> +
> + /* Byte 5-8: Interrupt Number */
> + acpigen_emit_dword(ctx, irq->pin);
> +
> + /* Fill in Descriptor Length (account for len word) */
> + acpi_device_fill_len(ctx, desc_length);
> +
> + return 0;
> +}
> +
> +int acpi_device_write_interrupt_irq(struct acpi_ctx *ctx,
> + const struct irq *req_irq)
> +{
> + struct acpi_irq irq;
> + int ret;
> +
> + ret = irq_get_acpi(req_irq, &irq);
> + if (ret)
> + return log_msg_ret("get", ret);
> + ret = acpi_device_write_interrupt(ctx, &irq);
> + if (ret)
> + return log_msg_ret("write", ret);
> +
> + return 0;
> +}
> diff --git a/test/dm/acpigen.c b/test/dm/acpigen.c
> index c353408021..4ee5c9cfe2 100644
> --- a/test/dm/acpigen.c
> +++ b/test/dm/acpigen.c
> @@ -8,8 +8,10 @@
>
> #include <common.h>
> #include <dm.h>
> +#include <irq.h>
> #include <malloc.h>
> #include <acpi/acpigen.h>
> +#include <acpi/acpi_device.h>
> #include <asm/unaligned.h>
> #include <dm/acpi.h>
> #include <dm/test.h>
> @@ -67,3 +69,32 @@ static int dm_test_acpi_emit_simple(struct unit_test_state *uts)
> return 0;
> }
> DM_TEST(dm_test_acpi_emit_simple, 0);
> +
> +/* Test emitting an interrupt descriptor */
> +static int dm_test_acpi_interrupt(struct unit_test_state *uts)
> +{
> + struct acpi_ctx *ctx;
> + struct udevice *dev;
> + struct irq irq;
> + u8 *ptr;
> +
> + ut_assertok(alloc_context(&ctx));
> +
> + ptr = acpigen_get_current(ctx);
> +
> + ut_assertok(uclass_first_device_err(UCLASS_TEST_FDT, &dev));
> + ut_assertok(irq_get_by_index(dev, 0, &irq));
> +
> + ut_assertok(acpi_device_write_interrupt_irq(ctx, &irq));
> + ut_asserteq(9, acpigen_get_current(ctx) - ptr);
> + ut_asserteq(ACPI_DESCRIPTOR_INTERRUPT, ptr[0]);
> + ut_asserteq(6, get_unaligned((u16 *)(ptr + 1)));
> + ut_asserteq(0x19, ptr[3]);
> + ut_asserteq(1, ptr[4]);
> + ut_asserteq(3, get_unaligned((u32 *)(ptr + 5)));
> +
> + free_context(&ctx);
> +
> + return 0;
> +}
> +DM_TEST(dm_test_acpi_interrupt, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
> --
Regards,
Bin
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