[PATCH v2 06/35] acpi: Support generation of interrupt descriptor

[Wolfgang Wallner]

Hi Simon,


-----"Simon Glass" <sjg at chromium.org> schrieb: -----
> Betreff: [PATCH v2 06/35] acpi: Support generation of interrupt descriptor
> 
> Add a function to write an interrupt descriptor to the generated ACPI
> code.
> 
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
> 
> Changes in v2: None
> Changes in v1: None
> 
>  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

[snip]

> @@ -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)
> + */
> +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 = 1 << 0; /* ResourceConsumer */

Nit: BIT(0), etc. ?

> +	if (irq->mode == ACPI_IRQ_EDGE_TRIGGERED)
> +		flags |= 1 << 1;
> +	if (irq->polarity == ACPI_IRQ_ACTIVE_LOW)
> +		flags |= 1 << 2;
> +	if (irq->shared == ACPI_IRQ_SHARED)
> +		flags |= 1 << 3;
> +	if (irq->wake == ACPI_IRQ_WAKE)
> +		flags |= 1 << 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;
> +}
> +

[snip]

Reviewed-by: Wolfgang Wallner <wolfgang.wallner at br-automation.com>