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.

Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

drivers/clk/bcm/clk-bcm2835.c

@@ -1239,6 +1239,12 @@ static struct clk *bcm2835_register_clock(struct bcm2835_cprman *cprman,
 	} else {
 		init.ops = &bcm2835_clock_clk_ops;
 		init.flags |= CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;
+
+		/* If the clock wasn't actually enabled at boot, it's not
+		 * critical.
+		 */
+		if (!(cprman_read(cprman, data->ctl_reg) & CM_ENABLE))
+			init.flags &= ~CLK_IS_CRITICAL;
 	}
 
 	clock = devm_kzalloc(cprman->dev, sizeof(*clock), GFP_KERNEL);
@@ -1708,13 +1714,15 @@ static const struct bcm2835_clk_desc clk_desc_array[] = {
 		.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(