soc: renesas: rcar-sysc: Add support for fixing up power area tables

The same SoC may have different power areas, depending on SoC revision.
One option is to use different sets of power area tables for each SoC
revision.  However, if the differences are small, it is much more
space-efficient to have a single set of tables, and fix those up at
runtime instead.

Hence provide a helper to NULLify power areas that do not exist on some
revisions (NULLified power areas are skipped during the registration
phase), and support for an optional initialization callback to e.g. fix
up power area tables.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

1 files changed, 24 insertions, 1 deletions

diff --git a/drivers/soc/renesas/rcar-sysc.c b/drivers/soc/renesas/rcar-sysc.c
index 225c35c79d9a..528a13742aeb 100644
--- a/drivers/soc/renesas/rcar-sysc.c
+++ b/drivers/soc/renesas/rcar-sysc.c
@@ -2,7 +2,7 @@
  * R-Car SYSC Power management support
  *
  * Copyright (C) 2014  Magnus Damm
- * Copyright (C) 2015-2016 Glider bvba
+ * Copyright (C) 2015-2017 Glider bvba
  *
  * This file is subject to the terms and conditions of the GNU General Public
  * License.  See the file "COPYING" in the main directory of this archive
@@ -334,6 +334,12 @@ static int __init rcar_sysc_pd_init(void)
 
 	info = match->data;
 
+	if (info->init) {
+		error = info->init();
+		if (error)
+			return error;
+	}
+
 	has_cpg_mstp = of_find_compatible_node(NULL, NULL,
 					       "renesas,cpg-mstp-clocks");
 
@@ -377,6 +383,11 @@ static int __init rcar_sysc_pd_init(void)
 		const struct rcar_sysc_area *area = &info->areas[i];
 		struct rcar_sysc_pd *pd;
 
+		if (!area->name) {
+			/* Skip NULLified area */
+			continue;
+		}
+
 		pd = kzalloc(sizeof(*pd) + strlen(area->name) + 1, GFP_KERNEL);
 		if (!pd) {
 			error = -ENOMEM;
@@ -406,6 +417,18 @@ out_put:
 }
 early_initcall(rcar_sysc_pd_init);
 
+void __init rcar_sysc_nullify(struct rcar_sysc_area *areas,
+			      unsigned int num_areas, u8 id)
+{
+	unsigned int i;
+
+	for (i = 0; i < num_areas; i++)
+		if (areas[i].isr_bit == id) {
+			areas[i].name = NULL;
+			return;
+		}
+}
+
 void __init rcar_sysc_init(phys_addr_t base, u32 syscier)
 {
 	u32 syscimr;