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authorFurquan Shaikh <furquan@chromium.org>2016-10-21 16:37:41 -0700
committerFurquan Shaikh <furquan@google.com>2016-10-25 00:13:16 +0200
commitc00bd18b13f67bf7721d49c89c2d6086c6f9118e (patch)
treea35d2dc9f17896fa5dda9ee99be2e142def7cbb2 /src/arch/x86/acpigen.c
parent1d33488968573888ea1fc386b7ede0bc67e9b32c (diff)
downloadcoreboot-c00bd18b13f67bf7721d49c89c2d6086c6f9118e.tar.xz
arch/x86/acpigen: Add support for _DSM method generation
Add acpigen_write_dsm that generates ACPI AML code for _DSM method. Caller should provide set of callbacks with callback[i] corresponding to function index i of DSM method. Local0 and Local1 should not be used in any of the callbacks. BUG=chrome-os-partner:57846 Change-Id: Ie18cba080424488fe00cc626ea50aa92c1dbb199 Signed-off-by: Furquan Shaikh <furquan@chromium.org> Reviewed-on: https://review.coreboot.org/17090 Tested-by: build bot (Jenkins) Reviewed-by: Alexander Couzens <lynxis@fe80.eu> Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Diffstat (limited to 'src/arch/x86/acpigen.c')
-rw-r--r--src/arch/x86/acpigen.c86
1 files changed, 86 insertions, 0 deletions
diff --git a/src/arch/x86/acpigen.c b/src/arch/x86/acpigen.c
index 35735b5cc9..42d42044af 100644
--- a/src/arch/x86/acpigen.c
+++ b/src/arch/x86/acpigen.c
@@ -1046,6 +1046,92 @@ void acpigen_write_return_byte(uint8_t arg)
acpigen_write_byte(arg);
}
+/*
+ * Generate ACPI AML code for _DSM method.
+ * This function takes as input uuid for the device, set of callbacks and
+ * argument to pass into the callbacks. Callbacks should ensure that Local0 and
+ * Local1 are left untouched. Use of Local2-Local7 is permitted in callbacks.
+ *
+ * Arguments passed into _DSM method:
+ * Arg0 = UUID
+ * Arg1 = Revision
+ * Arg2 = Function index
+ * Arg3 = Function specific arguments
+ *
+ * AML code generated would look like:
+ * Method (_DSM, 4, Serialized) {
+ * ToBuffer (Arg0, Local0)
+ * If (LEqual (Local0, ToUUID(uuid))) {
+ * ToInteger (Arg2, Local1)
+ * If (LEqual (Local1, 0)) {
+ * <acpigen by callback[0]>
+ * } Else {
+ * ...
+ * If (LEqual (Local1, n)) {
+ * <acpigen by callback[n]>
+ * } Else {
+ * Return (Buffer (One) { 0x0 })
+ * }
+ * }
+ * } Else {
+ * Return (Buffer (One) { 0x0 })
+ * }
+ * }
+ */
+void acpigen_write_dsm(const char *uuid, void (*callbacks[])(void *),
+ size_t count, void *arg)
+{
+ size_t i;
+
+ /* Method (_DSM, 4, Serialized) */
+ acpigen_write_method_serialized("_DSM", 0x4);
+
+ /* ToBuffer (Arg0, Local0) */
+ acpigen_write_to_buffer(ARG0_OP, LOCAL0_OP);
+
+ /* If (LEqual (Local0, ToUUID(uuid))) */
+ acpigen_write_if();
+ acpigen_emit_byte(LEQUAL_OP);
+ acpigen_emit_byte(LOCAL0_OP);
+ acpigen_write_uuid(uuid);
+
+ /* ToInteger (Arg2, Local1) */
+ acpigen_write_to_integer(ARG2_OP, LOCAL1_OP);
+ acpigen_write_debug_op(LOCAL1_OP);
+
+ for (i = 0; i < count; i++) {
+ /* If (Lequal (Local1, i)) */
+ acpigen_write_if_lequal(LOCAL1_OP, i);
+
+ /* Callback to write if handler. */
+ if (callbacks[i])
+ callbacks[i](arg);
+
+ acpigen_pop_len(); /* If */
+
+ /* Else */
+ acpigen_write_else();
+ }
+
+ /* Default case: Return (Buffer (One) { 0x0 }) */
+ acpigen_write_return_singleton_buffer(0x0);
+
+ /* Pop lengths for all the else clauses. */
+ for (i = 0; i < count; i++)
+ acpigen_pop_len();
+
+ acpigen_pop_len(); /* If (LEqual (Local0, ToUUID(uuid))) */
+
+ /* Else */
+ acpigen_write_else();
+
+ /* Return (Buffer (One) { 0x0 }) */
+ acpigen_write_return_singleton_buffer(0x0);
+
+ acpigen_pop_len(); /* Else */
+ acpigen_pop_len(); /* Method _DSM */
+}
+
/* Soc-implemented functions -- weak definitions. */
int __attribute__((weak)) acpigen_soc_read_rx_gpio(unsigned int gpio_num)
{