openwrt/target/linux/brcm2708/patches-4.4/0346-clk-bcm2835-Mark-GPIO-...

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From 3ee855d8520adaba936bccf377433468fb1c3ab0 Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Mon, 9 May 2016 17:28:18 -0700
Subject: [PATCH] clk: bcm2835: Mark GPIO clocks enabled at boot as critical.
These divide off of PLLD_PER and are used for the ethernet and wifi
PHYs source PLLs. Neither of them is currently represented by a phy
device that would grab the clock for us.
This keeps other drivers from killing the networking PHYs when they
disable their own clocks and trigger PLLD_PER's refcount going to 0.
v2: Skip marking as critical if they aren't on at boot.
Signed-off-by: Eric Anholt <eric@anholt.net>
---
drivers/clk/bcm/clk-bcm2835.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -1248,6 +1248,15 @@ static struct clk *bcm2835_register_cloc
init.name = data->name;
init.flags = data->flags | CLK_IGNORE_UNUSED;
+ /*
+ * Some GPIO clocks for ethernet/wifi PLLs are marked as
+ * critical (since some platforms use them), but if the
+ * firmware didn't have them turned on then they clearly
+ * aren't actually critical.
+ */
+ if ((cprman_read(cprman, data->ctl_reg) & CM_ENABLE) == 0)
+ init.flags &= ~CLK_IS_CRITICAL;
+
if (data->is_vpu_clock) {
init.ops = &bcm2835_vpu_clock_clk_ops;
} else {
@@ -1722,13 +1731,15 @@ static const struct bcm2835_clk_desc clk
.div_reg = CM_GP1DIV,
.int_bits = 12,
.frac_bits = 12,
+ .flags = CLK_IS_CRITICAL,
.is_mash_clock = true),
[BCM2835_CLOCK_GP2] = REGISTER_PER_CLK(
.name = "gp2",
.ctl_reg = CM_GP2CTL,
.div_reg = CM_GP2DIV,
.int_bits = 12,
- .frac_bits = 12),
+ .frac_bits = 12,
+ .flags = CLK_IS_CRITICAL),
/* HDMI state machine */
[BCM2835_CLOCK_HSM] = REGISTER_PER_CLK(