[PATCH] EDAC, altera: wrap edac pm with a CONFIG_PM

[<dinguyen@opensource.altera.com>]

From: Alan Tull <atull@opensource.altera.com>

Suspend-to-RAM and EDAC support are mutually exclusive on
SOCFPGA.  If the EDAC is enabled, it will prevent the
platform from going into suspend.

Signed-off-by: Alan Tull <atull@opensource.altera.com>
Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Acked-by: Borislav Petkov <bp@suse.de>
---
Hi Boris,

Please apply this patch to your for-next? This was part of Alan Tull's
suspend-to-ram patch that I was going to take through arm-soc. But if
I left the patch as it was, it would have caused a merge conflict for
v4.2.

Thanks,
Dinh
---
 drivers/edac/altera_edac.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/edac/altera_edac.c b/drivers/edac/altera_edac.c
index 182c741..23ef091 100644
--- a/drivers/edac/altera_edac.c
+++ b/drivers/edac/altera_edac.c
@@ -477,11 +477,31 @@ static int altr_sdram_remove(struct platform_device *pdev)
 	return 0;
 }
 
+/*
+ * If you want to suspend, need to disable EDAC by removing it
+ * from the device tree or defconfig.
+ */
+#ifdef CONFIG_PM
+static int altr_sdram_prepare(struct device *dev)
+{
+	pr_err("Suspend not allowed when EDAC is enabled.\n");
+
+	return -EPERM;
+}
+
+static const struct dev_pm_ops altr_sdram_pm_ops = {
+	.prepare = altr_sdram_prepare,
+};
+#endif
+
 static struct platform_driver altr_sdram_edac_driver = {
 	.probe = altr_sdram_probe,
 	.remove = altr_sdram_remove,
 	.driver = {
 		.name = "altr_sdram_edac",
+#ifdef CONFIG_PM
+		.pm = &altr_sdram_pm_ops,
+#endif
 		.of_match_table = altr_sdram_ctrl_of_match,
 	},
 };
-- 
2.2.1