ec/google/chromeec: Fix \_SB.DPTF._OSC

The DPTF._OSC method incorrectly assumed that all available UUIDs would
be present in the IDSP package, but this is not always the case. Instead
of matching an incoming UUID against an index into IDSP, search the IDSP
package for the matching UUID.

Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Change-Id: I718b6abe09152647b14f7c1405b2d0d20035726b
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43531
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>

src/ec/google/chromeec/ec_dptf_helpers.c

@@ -124,25 +124,91 @@ static void write_fan_fsl(const struct device *ec)
 	acpigen_pop_len(); /* Method _FSL */
 }
 
-/* Note: requires manual insertion of acpigen_pop_len() for the If */
+/*
-static void write_is_policy_enabled(unsigned int index, bool enabled)
+ * Emit code to execute if the policy is enabled after this function is called, and also
+ * remember to manually add a acpigen_pop_len() afterwards!
+ */
+static void write_is_policy_enabled(bool enabled)
 {
 	/*
-	 * If (And (LEqual (Deref (Index (IDSP, index)), Arg0))
+	 * Local0 = SizeOf (IDSP)
-	 *	   (LEqual (Arg1, enabled)))
+	 * Local1 = 0
+	 * Local2 = 0
+	 *
+	 * While (Local1 < Local) {
+	 *    If (IDSP[Local1] == Arg0 && Arg1 == enabled) {
+	 *        Local2 = 1
+	 *    }
+	 *    Local1++
+	 * }
+	 *
+	 * If (Local2 == 1) {
+	 * ..........
 	 */
+
+	/* Local0 = SizeOf (IDSP) */
+	acpigen_write_store();
+	acpigen_emit_byte(SIZEOF_OP);
+	acpigen_emit_namestring("IDSP");
+	acpigen_emit_byte(LOCAL0_OP);
+
+	/* Local1 = 0 (index variable) */
+	acpigen_write_store();
+	acpigen_write_zero();
+	acpigen_emit_byte(LOCAL1_OP);
+
+	/* Local2 = 0 (out variable, 1=found, 0=not found) */
+	acpigen_write_store();
+	acpigen_write_zero();
+	acpigen_emit_byte(LOCAL2_OP);
+
+	/*
+	 * While (Local1 < Local0) {
+	 */
+	acpigen_emit_byte(WHILE_OP);
+	acpigen_write_len_f();
+	acpigen_emit_byte(LNOT_OP);
+	acpigen_emit_byte(LGREATER_OP);
+	acpigen_emit_byte(LOCAL1_OP);
+	acpigen_emit_byte(LOCAL0_OP);
+
+	/* If (IDSP[Local1] == Arg0 && Arg1 == 1) { */
 	acpigen_write_if();
 	acpigen_emit_byte(LAND_OP);
 	acpigen_emit_byte(LEQUAL_OP);
 	acpigen_emit_byte(DEREF_OP);
 	acpigen_emit_byte(INDEX_OP);
 	acpigen_emit_namestring("IDSP");
-	acpigen_write_integer(index);
+	acpigen_emit_byte(LOCAL1_OP);
 	acpigen_emit_byte(ZERO_OP); /* 3rd arg of index - unused */
 	acpigen_emit_byte(ARG0_OP); /* end lequal */
 	acpigen_emit_byte(LEQUAL_OP);
 	acpigen_emit_byte(ARG1_OP);
 	acpigen_write_integer(enabled ? 1 : 0);
+
+	/* { Local2 = 1 } */
+	acpigen_write_store();
+	acpigen_write_one();
+	acpigen_emit_byte(LOCAL2_OP);
+	acpigen_pop_len(); /* If */
+
+	/*
+	 * Local1++
+	 * } # End of While
+	 */
+	acpigen_emit_byte(INCREMENT_OP);
+	acpigen_emit_byte(LOCAL1_OP);
+	acpigen_pop_len(); /* While */
+
+	/*
+	 * If (Local2 == 1)
+	 */
+	acpigen_write_if();
+	acpigen_emit_byte(LEQUAL_OP);
+	acpigen_emit_byte(LOCAL2_OP);
+	acpigen_write_one();
+
+	/* caller must insert acpigen_pop_len() ! */
 }
 
 static void write_dptf_OSC(const struct device *ec)
@@ -165,21 +231,21 @@ static void write_dptf_OSC(const struct device *ec)
 	 * 1) Disable temperature sensor trip points in the EC (replaces TINI)
 	 * 2) Disable the charge limit in the EC (replaces TCHG.INIT)
 	 */
-	write_is_policy_enabled(0, true);
+	write_is_policy_enabled(true);
 	for (i = 0; i < DPTF_MAX_TSR; ++i) {
 		snprintf(name, sizeof(name), "^TSR%1d.PATD", i);
 		acpigen_emit_namestring(name);
 	}
 
 	acpigen_emit_namestring(acpi_device_path_join(ec, "CHGD"));
-	acpigen_pop_len(); /* If */
+	acpigen_pop_len(); /* If (from write_is_policy_enabled) */
 
 	/* If the Active Policy is disabled, disable DPTF fan control in the EC */
-	write_is_policy_enabled(2, false);
+	write_is_policy_enabled(false);
 	acpigen_write_store();
 	acpigen_write_integer(EC_FAN_DUTY_AUTO);
 	acpigen_emit_namestring(acpi_device_path_join(ec, "FAND"));
-	acpigen_pop_len(); /* If */
+	acpigen_pop_len(); /* If (from write_is_policy_enabled) */
 
 	acpigen_write_return_op(ARG3_OP);
 	acpigen_pop_len(); /* Method _OSC */