clk: tegra: Support BPMP-FW ABI deny flags

Support BPMP_CLK_STATE_CHANGE_DENIED by not populating state changing
operations when the flag is set.

Support BPMP_CLK_RATE_PARENT_CHANGE_DENIED by not populating rate or
parent changing operations when the flag is set.
Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/clk/tegra/clk-bpmp.c

 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Copyright (C) 2016-2020 NVIDIA Corporation
+ * Copyright (C) 2016-2022 NVIDIA Corporation
  */
 
 #include <linux/clk-provider.h>
@@ -310,6 +310,23 @@ static const struct clk_ops tegra_bpmp_clk_mux_rate_ops = {
 	.set_rate = tegra_bpmp_clk_set_rate,
 };
 
+static const struct clk_ops tegra_bpmp_clk_mux_read_only_ops = {
+	.get_parent = tegra_bpmp_clk_get_parent,
+	.recalc_rate = tegra_bpmp_clk_recalc_rate,
+};
+
+static const struct clk_ops tegra_bpmp_clk_read_only_ops = {
+	.recalc_rate = tegra_bpmp_clk_recalc_rate,
+};
+
+static const struct clk_ops tegra_bpmp_clk_gate_mux_read_only_ops = {
+	.prepare = tegra_bpmp_clk_prepare,
+	.unprepare = tegra_bpmp_clk_unprepare,
+	.is_prepared = tegra_bpmp_clk_is_prepared,
+	.recalc_rate = tegra_bpmp_clk_recalc_rate,
+	.get_parent = tegra_bpmp_clk_get_parent,
+};
+
 static int tegra_bpmp_clk_get_max_id(struct tegra_bpmp *bpmp)
 {
 	struct cmd_clk_get_max_clk_id_response response;
@@ -510,8 +527,22 @@ tegra_bpmp_clk_register(struct tegra_bpmp *bpmp,
 	memset(&init, 0, sizeof(init));
 	init.name = info->name;
 	clk->hw.init = &init;
-
-	if (info->flags & TEGRA_BPMP_CLK_HAS_MUX) {
+	if (info->flags & BPMP_CLK_STATE_CHANGE_DENIED) {
+		if ((info->flags & BPMP_CLK_RATE_PARENT_CHANGE_DENIED) == 0) {
+			dev_WARN(bpmp->dev,
+				"Firmware bug! Inconsistent permission bits for clock %s. State and parent/rate changes disabled.",
+				 init.name);
+		}
+		if (info->flags & TEGRA_BPMP_CLK_HAS_MUX)
+			init.ops = &tegra_bpmp_clk_mux_read_only_ops;
+		else
+			init.ops = &tegra_bpmp_clk_read_only_ops;
+	} else if (info->flags & BPMP_CLK_RATE_PARENT_CHANGE_DENIED) {
+		if (info->flags & TEGRA_BPMP_CLK_HAS_MUX)
+			init.ops = &tegra_bpmp_clk_gate_mux_read_only_ops;
+		else
+			init.ops = &tegra_bpmp_clk_gate_ops;
+	} else if (info->flags & TEGRA_BPMP_CLK_HAS_MUX) {
 		if (info->flags & TEGRA_BPMP_CLK_HAS_SET_RATE)
 			init.ops = &tegra_bpmp_clk_mux_rate_ops;
 		else