[PATCH v3 13/57] acpi: Support generating a multi-function _DSM for devices

Simon Glass
2020-09-06T21:43:21Z

Add a function to generate ACPI code for a _DSM method for a device.
This includes functions for starting and ending each part of the _DSM.

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

(no changes since v1)

include/acpi/acpi_device.h | 14 +++++
include/acpi/acpigen.h | 99 +++++++++++++++++++++++++++++
lib/acpi/acpi_device.c | 43 +++++++++++++
lib/acpi/acpigen.c | 54 ++++++++++++++++
test/dm/acpigen.c | 126 +++++++++++++++++++++++++++++++++++++
5 files changed, 336 insertions(+)

diff --git a/include/acpi/acpi_device.h b/include/acpi/acpi_device.h
index 11461e168d3..a5b12217820 100644
--- a/include/acpi/acpi_device.h
+++ b/include/acpi/acpi_device.h
@@ -28,6 +28,9 @@ struct udevice;
/* Length of a full path to an ACPI device */
#define ACPI_PATH_MAX 30

+/* UUID for an I2C _DSM method */
+#define ACPI_DSM_I2C_HID_UUID "3cdff6f7-4267-4555-ad05-b30a3d8938de"
+
/* Values that can be returned for ACPI device _STA method */
enum acpi_dev_status {
ACPI_DSTATUS_PRESENT = BIT(0),
@@ -319,6 +322,17 @@ int acpi_device_write_gpio_desc(struct acpi_ctx *ctx,
int acpi_device_write_interrupt_or_gpio(struct acpi_ctx *ctx,
struct udevice *dev, const char *prop);

+/**
+ * acpi_device_write_dsm_i2c_hid() - Write a device-specific method for HID
+ *
+ * This writes a DSM for an I2C Human-Interface Device based on the config
+ * provided
+ *
+ * @hid_desc_reg_offset: HID register offset
+ */
+int acpi_device_write_dsm_i2c_hid(struct acpi_ctx *ctx,
+ int hid_desc_reg_offset);
+
/**
* acpi_device_write_i2c_dev() - Write an I2C device to ACPI
*
diff --git a/include/acpi/acpigen.h b/include/acpi/acpigen.h
index fa9409e3528..34b3115bc9c 100644
--- a/include/acpi/acpigen.h
+++ b/include/acpi/acpigen.h
@@ -666,4 +666,103 @@ void acpigen_write_return_singleton_buffer(struct acpi_ctx *ctx, uint arg);
*/
void acpigen_write_return_byte(struct acpi_ctx *ctx, uint arg);

+/**
+ * acpigen_write_dsm_start() - Start a _DSM method
+ *
+ * Generate ACPI AML code to start the _DSM method.
+ *
+ * The functions need to be called in the correct sequence as below.
+ *
+ * Within the <generate-code-here> region, Local0 and Local1 must be are left
+ * untouched, but Local2-Local7 can be used
+ *
+ * Arguments passed into _DSM method:
+ * Arg0 = UUID
+ * Arg1 = Revision
+ * Arg2 = Function index
+ * Arg3 = Function-specific arguments
+ *
+ * AML code generated looks like this:
+ * Method (_DSM, 4, Serialized) { -- acpigen_write_dsm_start)
+ * ToBuffer (Arg0, Local0)
+ * If (LEqual (Local0, ToUUID(uuid))) { -- acpigen_write_dsm_uuid_start
+ * ToInteger (Arg2, Local1)
+ * If (LEqual (Local1, 0)) { -- acpigen_write_dsm_uuid_start_cond
+ * <generate-code-here>
+ * } -- acpigen_write_dsm_uuid_end_cond
+ * ...
+ * If (LEqual (Local1, n)) { -- acpigen_write_dsm_uuid_start_cond
+ * <generate-code-here>
+ * } -- acpigen_write_dsm_uuid_end_cond
+ * Return (Buffer (One) { 0x0 })
+ * } -- acpigen_write_dsm_uuid_end
+ * ...
+ * If (LEqual (Local0, ToUUID(uuidn))) {
+ * ...
+ * }
+ * Return (Buffer (One) { 0x0 }) -- acpigen_write_dsm_end
+ * }
+ *
+ * @ctx: ACPI context pointer
+ */
+void acpigen_write_dsm_start(struct acpi_ctx *ctx);
+
+/**
+ * acpigen_write_dsm_uuid_start() - Start a new UUID block
+ *
+ * This starts generation of code to handle a particular UUID:
+ *
+ * If (LEqual (Local0, ToUUID(uuid))) {
+ * ToInteger (Arg2, Local1)
+ *
+ * @ctx: ACPI context pointer
+ */
+int acpigen_write_dsm_uuid_start(struct acpi_ctx *ctx, const char *uuid);
+
+/**
+ * acpigen_write_dsm_uuid_start_cond() - Start a new condition block
+ *
+ * This starts generation of condition-checking code to handle a particular
+ * function:
+ *
+ * If (LEqual (Local1, i))
+ *
+ * @ctx: ACPI context pointer
+ */
+void acpigen_write_dsm_uuid_start_cond(struct acpi_ctx *ctx, int seq);
+
+/**
+ * acpigen_write_dsm_uuid_end_cond() - Start a new condition block
+ *
+ * This ends generation of condition-checking code to handle a particular
+ * function:
+ *
+ * }
+ *
+ * @ctx: ACPI context pointer
+ */
+void acpigen_write_dsm_uuid_end_cond(struct acpi_ctx *ctx);
+
+/**
+ * acpigen_write_dsm_uuid_end() - End a UUID block
+ *
+ * This ends generation of code to handle a particular UUID:
+ *
+ * Return (Buffer (One) { 0x0 })
+ *
+ * @ctx: ACPI context pointer
+ */
+void acpigen_write_dsm_uuid_end(struct acpi_ctx *ctx);
+
+/**
+ * acpigen_write_dsm_end() - End a _DSM method
+ *
+ * This ends generates of the _DSM block:
+ *
+ * Return (Buffer (One) { 0x0 })
+ *
+ * @ctx: ACPI context pointer
+ */
+void acpigen_write_dsm_end(struct acpi_ctx *ctx);
+
#endif
diff --git a/lib/acpi/acpi_device.c b/lib/acpi/acpi_device.c
index 3c75b6d9629..8248664a10a 100644
--- a/lib/acpi/acpi_device.c
+++ b/lib/acpi/acpi_device.c
@@ -487,6 +487,49 @@ int acpi_device_add_power_res(struct acpi_ctx *ctx, u32 tx_state_val,
return 0;
}

+int acpi_device_write_dsm_i2c_hid(struct acpi_ctx *ctx,
+ int hid_desc_reg_offset)
+{
+ int ret;
+
+ acpigen_write_dsm_start(ctx);
+ ret = acpigen_write_dsm_uuid_start(ctx, ACPI_DSM_I2C_HID_UUID);
+ if (ret)
+ return log_ret(ret);
+
+ acpigen_write_dsm_uuid_start_cond(ctx, 0);
+ /* ToInteger (Arg1, Local2) */
+ acpigen_write_to_integer(ctx, ARG1_OP, LOCAL2_OP);
+ /* If (LEqual (Local2, 0x0)) */
+ acpigen_write_if_lequal_op_int(ctx, LOCAL2_OP, 0x0);
+ /* Return (Buffer (One) { 0x1f }) */
+ acpigen_write_return_singleton_buffer(ctx, 0x1f);
+ acpigen_pop_len(ctx); /* Pop : If */
+ /* Else */
+ acpigen_write_else(ctx);
+ /* If (LEqual (Local2, 0x1)) */
+ acpigen_write_if_lequal_op_int(ctx, LOCAL2_OP, 0x1);
+ /* Return (Buffer (One) { 0x3f }) */
+ acpigen_write_return_singleton_buffer(ctx, 0x3f);
+ acpigen_pop_len(ctx); /* Pop : If */
+ /* Else */
+ acpigen_write_else(ctx);
+ /* Return (Buffer (One) { 0x0 }) */
+ acpigen_write_return_singleton_buffer(ctx, 0x0);
+ acpigen_pop_len(ctx); /* Pop : Else */
+ acpigen_pop_len(ctx); /* Pop : Else */
+ acpigen_write_dsm_uuid_end_cond(ctx);
+
+ acpigen_write_dsm_uuid_start_cond(ctx, 1);
+ acpigen_write_return_byte(ctx, hid_desc_reg_offset);
+ acpigen_write_dsm_uuid_end_cond(ctx);
+
+ acpigen_write_dsm_uuid_end(ctx);
+ acpigen_write_dsm_end(ctx);
+
+ return 0;
+}
+
/* ACPI 6.3 section 6.4.3.8.2.1 - I2cSerialBus() */
static void acpi_device_write_i2c(struct acpi_ctx *ctx,
const struct acpi_i2c *i2c)
diff --git a/lib/acpi/acpigen.c b/lib/acpi/acpigen.c
index 2518bf83dda..d859f378413 100644
--- a/lib/acpi/acpigen.c
+++ b/lib/acpi/acpigen.c
@@ -609,6 +609,60 @@ void acpigen_write_return_byte(struct acpi_ctx *ctx, uint arg)
acpigen_write_byte(ctx, arg);
}

+void acpigen_write_dsm_start(struct acpi_ctx *ctx)
+{
+ /* Method (_DSM, 4, Serialized) */
+ acpigen_write_method_serialized(ctx, "_DSM", 4);
+
+ /* ToBuffer (Arg0, Local0) */
+ acpigen_write_to_buffer(ctx, ARG0_OP, LOCAL0_OP);
+}
+
+int acpigen_write_dsm_uuid_start(struct acpi_ctx *ctx, const char *uuid)
+{
+ int ret;
+
+ /* If (LEqual (Local0, ToUUID(uuid))) */
+ acpigen_write_if(ctx);
+ acpigen_emit_byte(ctx, LEQUAL_OP);
+ acpigen_emit_byte(ctx, LOCAL0_OP);
+ ret = acpigen_write_uuid(ctx, uuid);
+ if (ret)
+ return log_msg_ret("uuid", ret);
+
+ /* ToInteger (Arg2, Local1) */
+ acpigen_write_to_integer(ctx, ARG2_OP, LOCAL1_OP);
+
+ return 0;
+}
+
+void acpigen_write_dsm_uuid_start_cond(struct acpi_ctx *ctx, int seq)
+{
+ /* If (LEqual (Local1, i)) */
+ acpigen_write_if_lequal_op_int(ctx, LOCAL1_OP, seq);
+}
+
+void acpigen_write_dsm_uuid_end_cond(struct acpi_ctx *ctx)
+{
+ acpigen_pop_len(ctx); /* If */
+}
+
+void acpigen_write_dsm_uuid_end(struct acpi_ctx *ctx)
+{
+ /* Default case: Return (Buffer (One) { 0x0 }) */
+ acpigen_write_return_singleton_buffer(ctx, 0x0);
+
+ acpigen_pop_len(ctx); /* If (LEqual (Local0, ToUUID(uuid))) */
+}
+
+void acpigen_write_dsm_end(struct acpi_ctx *ctx)
+{
+ /* Return (Buffer (One) { 0x0 }) */
+ acpigen_write_return_singleton_buffer(ctx, 0x0);
+
+ acpigen_pop_len(ctx); /* Method _DSM */
+}
+
/**
* acpigen_get_dw0_in_local5() - Generate code to put dw0 cfg0 in local5
*
diff --git a/test/dm/acpigen.c b/test/dm/acpigen.c
index cce19f11209..381fcb97022 100644
--- a/test/dm/acpigen.c
+++ b/test/dm/acpigen.c
@@ -10,6 +10,7 @@
#include <dm.h>
#include <irq.h>
#include <malloc.h>
+#include <uuid.h>
#include <acpi/acpigen.h>
#include <acpi/acpi_device.h>
#include <acpi/acpi_table.h>
@@ -1218,3 +1219,128 @@ static int dm_test_acpi_write_return(struct unit_test_state *uts)
return 0;
}
DM_TEST(dm_test_acpi_write_return, 0);
+
+/* Test emitting a DSM for an I2C HID */
+static int dm_test_acpi_write_i2c_dsm(struct unit_test_state *uts)
+{
+ char uuid_str[UUID_STR_LEN + 1];
+ const int reg_offset = 0x20;
+ struct acpi_ctx *ctx;
+ u8 *ptr;
+
+ ut_assertok(alloc_context(&ctx));
+
+ ptr = acpigen_get_current(ctx);
+ ut_assertok(acpi_device_write_dsm_i2c_hid(ctx, reg_offset));
+
+ /* acpigen_write_dsm_start() */
+ ut_asserteq(METHOD_OP, *ptr++);
+ ut_asserteq(0x78, acpi_test_get_length(ptr));
+ ptr += 3;
+ ut_asserteq_strn("_DSM", (char *)ptr);
+ ptr += 4;
+ ut_asserteq(ACPI_METHOD_SERIALIZED_MASK | 4, *ptr++);
+
+ ut_asserteq(TO_BUFFER_OP, *ptr++);
+ ut_asserteq(ARG0_OP, *ptr++);
+ ut_asserteq(LOCAL0_OP, *ptr++);
+
+ /* acpigen_write_dsm_uuid_start() */
+ ut_asserteq(IF_OP, *ptr++);
+ ut_asserteq(0x65, acpi_test_get_length(ptr));
+ ptr += 3;
+ ut_asserteq(LEQUAL_OP, *ptr++);
+ ut_asserteq(LOCAL0_OP, *ptr++);
+
+ ut_asserteq(BUFFER_OP, *ptr++);
+ ut_asserteq(UUID_BIN_LEN + 6, acpi_test_get_length(ptr));
+ ptr += 3;
+ ut_asserteq(WORD_PREFIX, *ptr++);
+ ut_asserteq(UUID_BIN_LEN, get_unaligned((u16 *)ptr));
+ ptr += 2;
+ uuid_bin_to_str(ptr, uuid_str, UUID_STR_FORMAT_GUID);
+ ut_asserteq_str(ACPI_DSM_I2C_HID_UUID, uuid_str);
+ ptr += UUID_BIN_LEN;
+
+ ut_asserteq(TO_INTEGER_OP, *ptr++);
+ ut_asserteq(ARG2_OP, *ptr++);
+ ut_asserteq(LOCAL1_OP, *ptr++);
+
+ /* acpigen_write_dsm_uuid_start_cond() */
+ ut_asserteq(IF_OP, *ptr++);
+ ut_asserteq(0x34, acpi_test_get_length(ptr));
+ ptr += 3;
+ ut_asserteq(LEQUAL_OP, *ptr++);
+ ut_asserteq(LOCAL1_OP, *ptr++);
+ ut_asserteq(ZERO_OP, *ptr++);
+
+ /*
+ * See code from acpi_device_write_dsm_i2c_hid(). We don't check every
+ * piece
+ */
+ ut_asserteq(TO_INTEGER_OP, *ptr++);
+ ut_asserteq(ARG1_OP, *ptr++);
+ ut_asserteq(LOCAL2_OP, *ptr++);
+
+ ut_asserteq(IF_OP, *ptr++);
+ ut_asserteq(0xd, acpi_test_get_length(ptr));
+ ptr += 3;
+ ut_asserteq(LEQUAL_OP, *ptr++);
+ ut_asserteq(LOCAL2_OP, *ptr++);
+ ut_asserteq(ZERO_OP, *ptr++); /* function 0 */
+
+ ut_asserteq(RETURN_OP, *ptr++);
+ ut_asserteq(BUFFER_OP, *ptr++);
+ ptr += 5;
+
+ ut_asserteq(ELSE_OP, *ptr++);
+ ptr += 3;
+
+ ut_asserteq(IF_OP, *ptr++);
+ ut_asserteq(0xd, acpi_test_get_length(ptr));
+ ptr += 3;
+ ut_asserteq(LEQUAL_OP, *ptr++);
+ ut_asserteq(LOCAL2_OP, *ptr++);
+ ut_asserteq(ONE_OP, *ptr++);
+
+ ut_asserteq(RETURN_OP, *ptr++);
+ ut_asserteq(BUFFER_OP, *ptr++);
+ ptr += 5;
+
+ ut_asserteq(ELSE_OP, *ptr++);
+ ptr += 3;
+
+ ut_asserteq(RETURN_OP, *ptr++);
+ ut_asserteq(BUFFER_OP, *ptr++);
+ ptr += 5;
+
+ /* acpigen_write_dsm_uuid_start_cond() */
+ ut_asserteq(IF_OP, *ptr++);
+ ut_asserteq(9, acpi_test_get_length(ptr));
+ ptr += 3;
+ ut_asserteq(LEQUAL_OP, *ptr++);
+ ut_asserteq(LOCAL1_OP, *ptr++);
+ ut_asserteq(ONE_OP, *ptr++); /* function 1 */
+
+ ut_asserteq(RETURN_OP, *ptr++);
+ ut_asserteq(BYTE_PREFIX, *ptr++);
+ ut_asserteq(reg_offset, *ptr++);
+
+ /* acpigen_write_dsm_uuid_end() */
+ ut_asserteq(RETURN_OP, *ptr++);
+ ut_asserteq(BUFFER_OP, *ptr++);
+ ptr += 5;
+
+ /* acpigen_write_dsm_end */
+ ut_asserteq(RETURN_OP, *ptr++);
+ ut_asserteq(BUFFER_OP, *ptr++);
+ ptr += 5;
+
+ ut_asserteq_ptr(ptr, ctx->current);
+
+ free_context(&ctx);
+
+ return 0;
+}
+DM_TEST(dm_test_acpi_write_i2c_dsm, 0);
+
--
2.28.0.526.ge36021eeef-goog