[083/108] x86: acpi: Support generation of the HPET table

Message ID 20200126220508.83.If8823c046de531ba72920ef50bbae1dbc77d538b@changeid
State New
Headers show
Series
  • RFC: dm: Add programatic generation of ACPI tables
Related show

Commit Message

Simon Glass Jan. 27, 2020, 5:06 a.m.
Add an implementation of the HPET (High Precision Event Timer) ACPI
table.

Signed-off-by: Simon Glass <sjg at chromium.org>
---

 arch/x86/lib/acpi_table.c | 54 +++++++++++++++++++++++++++++++++++++++
 include/acpi_table.h      | 32 ++++++++++++++++-------
 2 files changed, 77 insertions(+), 9 deletions(-)

Patch

diff --git a/arch/x86/lib/acpi_table.c b/arch/x86/lib/acpi_table.c
index 4c35111c48..a810b12cfe 100644
--- a/arch/x86/lib/acpi_table.c
+++ b/arch/x86/lib/acpi_table.c
@@ -32,6 +32,26 @@  extern const unsigned char AmlCode[];
 /* ACPI RSDP address to be used in boot parameters */
 static ulong acpi_rsdp_addr;
 
+int acpi_write_hpet(struct acpi_ctx *ctx, const struct udevice *dev)
+{
+	struct acpi_hpet *hpet;
+	int ret;
+
+	/*
+	 * We explicitly add these tables later on:
+	 */
+	log_debug("ACPI:    * HPET\n");
+
+	hpet = ctx->current;
+	acpi_inc_align(ctx, sizeof(struct acpi_hpet));
+	acpi_create_hpet(hpet);
+	ret = acpi_add_table(ctx, hpet);
+	if (ret)
+		return log_msg_ret("add", ret);
+
+	return 0;
+}
+
 static void acpi_create_facs(struct acpi_facs *facs)
 {
 	memset((void *)facs, 0, sizeof(struct acpi_facs));
@@ -385,6 +405,40 @@  void acpi_create_ssdt(struct acpi_ctx *ctx, struct acpi_table_header *ssdt,
 	ssdt->checksum = table_compute_checksum((void *)ssdt, ssdt->length);
 }
 
+/* http://www.intel.com/hardwaredesign/hpetspec_1.pdf */
+int acpi_create_hpet(struct acpi_hpet *hpet)
+{
+	struct acpi_table_header *header = &hpet->header;
+	struct acpi_gen_regaddr *addr = &hpet->addr;
+
+	memset((void *)hpet, 0, sizeof(struct acpi_hpet));
+	if (!header)
+		return -EFAULT;
+
+	/* Fill out header fields. */
+	acpi_fill_header(header, "HPET");
+
+	header->aslc_revision = ASL_REVISION;
+	header->length = sizeof(struct acpi_hpet);
+	header->revision = acpi_get_table_revision(ACPITAB_HPET);
+
+	/* Fill out HPET address. */
+	addr->space_id = 0; /* Memory */
+	addr->bit_width = 64;
+	addr->bit_offset = 0;
+	addr->addrl = CONFIG_HPET_ADDRESS & 0xffffffff;
+	addr->addrh = ((unsigned long long)CONFIG_HPET_ADDRESS) >> 32;
+
+	hpet->id = *(unsigned int *)CONFIG_HPET_ADDRESS;
+	hpet->number = 0;
+	hpet->min_tick = 0; /* HPET_MIN_TICKS */
+
+	header->checksum = table_compute_checksum((void *)hpet,
+						  sizeof(struct acpi_hpet));
+
+	return 0;
+}
+
 /*
  * QEMU's version of write_acpi_tables is defined in drivers/misc/qfw.c
  */
diff --git a/include/acpi_table.h b/include/acpi_table.h
index e3dedc2496..1d78665abe 100644
--- a/include/acpi_table.h
+++ b/include/acpi_table.h
@@ -70,6 +70,15 @@  struct __packed acpi_table_header {
 	u32 aslc_revision;	/* ASL compiler revision number */
 };
 
+struct acpi_gen_regaddr {
+	u8 space_id;	/* Address space ID */
+	u8 bit_width;	/* Register size in bits */
+	u8 bit_offset;	/* Register bit offset */
+	u8 access_size;	/* Access size */
+	u32 addrl;	/* Register address, low 32 bits */
+	u32 addrh;	/* Register address, high 32 bits */
+};
+
 /* A maximum number of 32 ACPI tables ought to be enough for now */
 #define MAX_ACPI_TABLES		32
 
@@ -85,6 +94,16 @@  struct acpi_xsdt {
 	u64 entry[MAX_ACPI_TABLES];
 };
 
+/* HPET timers */
+struct __packed acpi_hpet {
+	struct acpi_table_header header;
+	u32 id;
+	struct acpi_gen_regaddr addr;
+	u8 number;
+	u16 min_tick;
+	u8 attributes;
+};
+
 /* FADT Preferred Power Management Profile */
 enum acpi_pm_profile {
 	ACPI_PM_UNSPECIFIED = 0,
@@ -152,15 +171,6 @@  enum acpi_address_space_size {
 	ACPI_ACCESS_SIZE_QWORD_ACCESS
 };
 
-struct acpi_gen_regaddr {
-	u8 space_id;	/* Address space ID */
-	u8 bit_width;	/* Register size in bits */
-	u8 bit_offset;	/* Register bit offset */
-	u8 access_size;	/* Access size */
-	u32 addrl;	/* Register address, low 32 bits */
-	u32 addrh;	/* Register address, high 32 bits */
-};
-
 /* FADT (Fixed ACPI Description Table) */
 struct __packed acpi_fadt {
 	struct acpi_table_header header;
@@ -617,6 +627,10 @@  int acpi_add_table(struct acpi_ctx *ctx, void *table);
  */
 void acpi_setup_base_tables(struct acpi_ctx *ctx, void *start);
 
+int acpi_write_hpet(struct acpi_ctx *ctx, const struct udevice *dev);
+
+int acpi_create_hpet(struct acpi_hpet *hpet);
+
 #endif /* !__ACPI__*/
 
 #include <asm/acpi_table.h>