acpigen: Add some new helper functions

These build on existing functions but use different object types
in order to provide functions for upcoming changes:

acpigen_write_return_op(): Return an operator.
acpigen_write_if_lequal_op_op(): Check if 2 operands are equal.
acpigen_get_package_op_element(): Read an element from a package
                                  into an operator.

This one just provides the missing helper, the other 3 already exist:
acpigen_get_tx_gpio: Read TX gpio state.

Signed-off-by: Duncan Laurie <dlaurie@google.com>
Change-Id: I1141fd132d6f09cf482f74e95308947cba2c5846
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41985
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

2 files changed, 60 insertions, 0 deletions

diff --git a/src/acpi/acpigen.c b/src/acpi/acpigen.c
index 793841cc5b..efc5a16195 100644
--- a/src/acpi/acpigen.c
+++ b/src/acpi/acpigen.c
@@ -339,6 +339,18 @@ void acpigen_write_scope(const char *name)
 	acpigen_emit_namestring(name);
 }
 
+void acpigen_get_package_op_element(uint8_t package_op, unsigned int element, uint8_t dest_op)
+{
+	/* <dest_op> = DeRefOf (<package_op>[<element]) */
+	acpigen_write_store();
+	acpigen_emit_byte(DEREF_OP);
+	acpigen_emit_byte(INDEX_OP);
+	acpigen_emit_byte(package_op);
+	acpigen_write_integer(element);
+	acpigen_emit_byte(ZERO_OP); /* Ignore Index() Destination */
+	acpigen_emit_byte(dest_op);
+}
+
 void acpigen_write_processor(u8 cpuindex, u32 pblock_addr, u8 pblock_len)
 {
 /*
@@ -1269,6 +1281,20 @@ void acpigen_write_if_and(uint8_t arg1, uint8_t arg2)
 }
 
 /*
+ * Generates ACPI code for checking if operand1 and operand2 are equal.
+ * Both operand1 and operand2 are ACPI ops.
+ *
+ * If (Lequal (op,1 op2))
+ */
+void acpigen_write_if_lequal_op_op(uint8_t op1, uint8_t op2)
+{
+	acpigen_write_if();
+	acpigen_emit_byte(LEQUAL_OP);
+	acpigen_emit_byte(op1);
+	acpigen_emit_byte(op2);
+}
+
+/*
  * Generates ACPI code for checking if operand1 and operand2 are equal, where,
  * operand1 is ACPI op and operand2 is an integer.
  *
@@ -1341,6 +1367,12 @@ void acpigen_write_return_singleton_buffer(uint8_t arg)
 	acpigen_write_return_byte_buffer(&arg, 1);
 }
 
+void acpigen_write_return_op(uint8_t arg)
+{
+	acpigen_emit_byte(RETURN_OP);
+	acpigen_emit_byte(arg);
+}
+
 void acpigen_write_return_byte(uint8_t arg)
 {
 	acpigen_emit_byte(RETURN_OP);
@@ -1790,6 +1822,14 @@ void acpigen_get_rx_gpio(struct acpi_gpio *gpio)
 		acpigen_write_xor(LOCAL0_OP, 1, LOCAL0_OP);
 }
 
+void acpigen_get_tx_gpio(struct acpi_gpio *gpio)
+{
+	acpigen_soc_get_tx_gpio(gpio->pins[0]);
+
+	if (gpio->polarity == ACPI_GPIO_ACTIVE_LOW)
+		acpigen_write_xor(LOCAL0_OP, 1, LOCAL0_OP);
+}
+
 /* refer to ACPI 6.4.3.5.3 Word Address Space Descriptor section for details */
 void acpigen_resource_word(u16 res_type, u16 gen_flags, u16 type_flags, u16 gran,
 	u16 range_min, u16 range_max, u16 translation, u16 length)
diff --git a/src/include/acpi/acpigen.h b/src/include/acpi/acpigen.h
index a99489de1f..dffde851f5 100644
--- a/src/include/acpi/acpigen.h
+++ b/src/include/acpi/acpigen.h
@@ -360,6 +360,7 @@ void acpigen_write_debug_integer(uint64_t val);
 void acpigen_write_debug_op(uint8_t op);
 void acpigen_write_if(void);
 void acpigen_write_if_and(uint8_t arg1, uint8_t arg2);
+void acpigen_write_if_lequal_op_op(uint8_t op, uint8_t val);
 void acpigen_write_if_lequal_op_int(uint8_t op, uint64_t val);
 void acpigen_write_if_lequal_namestr_int(const char *namestr, uint64_t val);
 void acpigen_write_else(void);
@@ -368,6 +369,7 @@ void acpigen_write_to_integer(uint8_t src, uint8_t dst);
 void acpigen_write_byte_buffer(uint8_t *arr, size_t size);
 void acpigen_write_return_byte_buffer(uint8_t *arr, size_t size);
 void acpigen_write_return_singleton_buffer(uint8_t arg);
+void acpigen_write_return_op(uint8_t arg);
 void acpigen_write_return_byte(uint8_t arg);
 void acpigen_write_upc(enum acpi_upc_type type);
 void acpigen_write_pld(const struct acpi_pld *pld);
@@ -439,6 +441,16 @@ void acpigen_write_indexfield(const char *idx, const char *data,
 int get_cst_entries(acpi_cstate_t **);
 
 /*
+ * Get element from package into specified destination op:
+ *   <dest_op> = DeRefOf (<package_op>[<element])
+ *
+ * Example:
+ *  acpigen_get_package_op_element(ARG0_OP, 0, LOCAL0_OP)
+ *  Local0 = DeRefOf (Arg0[0])
+ */
+void acpigen_get_package_op_element(uint8_t package_op, unsigned int element, uint8_t dest_op);
+
+/*
  * Soc-implemented functions for generating ACPI AML code for GPIO handling. All
  * these functions are expected to use only Local5, Local6 and Local7
  * variables. If the functions call into another ACPI method, then there is no
@@ -478,6 +490,14 @@ int acpigen_disable_tx_gpio(struct acpi_gpio *gpio);
  */
 void acpigen_get_rx_gpio(struct acpi_gpio *gpio);
 
+/*
+ *  Helper function for getting a TX GPIO value based on the GPIO polarity.
+ *  The return value is stored in Local0 variable.
+ *  This function ends up calling acpigen_soc_get_tx_gpio to make callbacks
+ *  into SoC acpigen code
+ */
+void acpigen_get_tx_gpio(struct acpi_gpio *gpio);
+
 /* refer to ACPI 6.4.3.5.3 Word Address Space Descriptor section for details */
 void acpigen_resource_word(u16 res_type, u16 gen_flags, u16 type_flags, u16 gran,
 	u16 range_min, u16 range_max, u16 translation, u16 length);