[PATCH v4 06/35] acpi: Support generation of interrupt descriptor
Simon Glass
sjg at chromium.org
Tue Jul 7 21:11:43 CEST 2020
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>
---
Changes in v4:
- Rename the length-writing functions to indicate they are for large resources
include/acpi/acpi_device.h | 15 +++++
lib/acpi/acpi_device.c | 119 +++++++++++++++++++++++++++++++++++++
test/dm/acpigen.c | 32 ++++++++++
3 files changed, 166 insertions(+)
diff --git a/include/acpi/acpi_device.h b/include/acpi/acpi_device.h
index 24895de0da..e72fede54c 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 IRQ pin number 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..d854a45cbc 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 +88,120 @@ enum acpi_dev_status acpi_device_status(const struct udevice *dev)
{
return ACPI_DSTATUS_ALL_ON;
}
+
+/**
+ * largeres_write_len_f() - Write a placeholder word value
+ *
+ * Write a forward length for a large resource (2 bytes)
+ *
+ * @return pointer to the zero word (for fixing up later)
+ */
+static void *largeres_write_len_f(struct acpi_ctx *ctx)
+{
+ u8 *p = acpigen_get_current(ctx);
+
+ acpigen_emit_word(ctx, 0);
+
+ return p;
+}
+
+/**
+ * largeres_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 largeres_write_len_f().
+ *
+ * @ptr: Word to update
+ * @start: Start address to count from to calculated the length
+ */
+static void largeres_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;
+}
+
+/**
+ * largeres_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_largeres_fill_len() passing @ptr + 2 as @start
+ *
+ * @ptr: Word to update.
+ */
+static void largeres_fill_len(struct acpi_ctx *ctx, void *ptr)
+{
+ largeres_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 = largeres_write_len_f(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) */
+ largeres_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 9ff9b68532..a4adfbfdf8 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>
@@ -70,3 +72,33 @@ 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));
+
+ /* See a-test, property interrupts-extended in the device tree */
+ ut_asserteq(3, 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);
--
2.27.0.383.g050319c2ae-goog
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