openwrt-archive/target/linux/brcm2708/patches-4.4/0348-clk-Allow-clocks-to-be-marked-as-CRITICAL.patch

From ac9a9b1fcf3b0255aebc8e7f4b809f15556d9640 Mon Sep 17 00:00:00 2001
From: Lee Jones <lee.jones@linaro.org>
Date: Thu, 11 Feb 2016 13:19:09 -0800
Subject: [PATCH 348/381] clk: Allow clocks to be marked as CRITICAL

Critical clocks are those which must not be gated, else undefined
or catastrophic failure would occur.  Here we have chosen to
ensure the prepare/enable counts are correctly incremented, so as
not to confuse users with enabled clocks with no visible users.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/1455225554-13267-2-git-send-email-mturquette@baylibre.com
(cherry picked from commit 32b9b10961860860268961d9aad0c56a73018c37)
---
 drivers/clk/clk.c            | 5 +++++
 include/linux/clk-provider.h | 1 +
 2 files changed, 6 insertions(+)

--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -2466,6 +2466,11 @@ static int __clk_init(struct device *dev
 	if (core->ops->init)
 		core->ops->init(core->hw);
 
+	if (core->flags & CLK_IS_CRITICAL) {
+		clk_core_prepare(core);
+		clk_core_enable(core);
+	}
+
 	kref_init(&core->ref);
 out:
 	clk_prepare_unlock();
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -31,6 +31,7 @@
 #define CLK_SET_RATE_NO_REPARENT BIT(7) /* don't re-parent on rate change */
 #define CLK_GET_ACCURACY_NOCACHE BIT(8) /* do not use the cached clk accuracy */
 #define CLK_RECALC_NEW_RATES	BIT(9) /* recalc rates after notifications */
+#define CLK_IS_CRITICAL		BIT(11) /* do not gate, ever */
 
 struct clk;
 struct clk_hw;