clk: Add hardware-enable column to clk summary

Add "hardware enable" column to the clk summary in order to show actual
hardware enable-state of all clocks. The possible states are "Y/N/?",
where question mark means that state is unknown, i.e. clock isn't a
mux and clk-driver doesn't support is_enabled() callback for this clock.

In conjunction with clk_ignore_unused, this tells us what unused clocks
are left enabled after bootloader. This is also a useful aid for
debugging interactions with firmware which changes clock states without
notifying kernel.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20201115203432.13934-1-digetx@gmail.comSigned-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/clk.c

@@ -2931,7 +2931,14 @@ static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
 	else
 		seq_puts(s, "-----");
 
-	seq_printf(s, " %6d\n", clk_core_get_scaled_duty_cycle(c, 100000));
+	seq_printf(s, " %6d", clk_core_get_scaled_duty_cycle(c, 100000));
+
+	if (c->ops->is_enabled)
+		seq_printf(s, " %9c\n", clk_core_is_enabled(c) ? 'Y' : 'N');
+	else if (!c->ops->enable)
+		seq_printf(s, " %9c\n", 'Y');
+	else
+		seq_printf(s, " %9c\n", '?');
 }
 
 static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
@@ -2950,9 +2957,9 @@ static int clk_summary_show(struct seq_file *s, void *data)
 	struct clk_core *c;
 	struct hlist_head **lists = (struct hlist_head **)s->private;
 
-	seq_puts(s, "                                 enable  prepare  protect                                duty\n");
-	seq_puts(s, "   clock                          count    count    count        rate   accuracy phase  cycle\n");
-	seq_puts(s, "---------------------------------------------------------------------------------------------\n");
+	seq_puts(s, "                                 enable  prepare  protect                                duty  hardware\n");
+	seq_puts(s, "   clock                          count    count    count        rate   accuracy phase  cycle    enable\n");
+	seq_puts(s, "-------------------------------------------------------------------------------------------------------\n");
 
 	clk_prepare_lock();