soc: actions: owl-sps: Factor out owl_sps_set_pg() for power-gating

[mirror_ubuntu-artful-kernel.git] / drivers / soc / actions / owl-sps-helper.c

diff --git a/drivers/soc/actions/owl-sps-helper.c b/drivers/soc/actions/owl-sps-helper.c
new file mode 100644 (file)
index 0000000..9d7a2c2
--- /dev/null
+++ b/drivers/soc/actions/owl-sps-helper.c
@@ -0,0 +1,51 @@
+/*
+ * Actions Semi Owl Smart Power System (SPS) shared helpers
+ *
+ * Copyright 2012 Actions Semi Inc.
+ * Author: Actions Semi, Inc.
+ *
+ * Copyright (c) 2017 Andreas Färber
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/delay.h>
+#include <linux/io.h>
+
+#define OWL_SPS_PG_CTL 0x0
+
+int owl_sps_set_pg(void __iomem *base, u32 pwr_mask, u32 ack_mask, bool enable)
+{
+       u32 val;
+       bool ack;
+       int timeout;
+
+       val = readl(base + OWL_SPS_PG_CTL);
+       ack = val & ack_mask;
+       if (ack == enable)
+               return 0;
+
+       if (enable)
+               val |= pwr_mask;
+       else
+               val &= ~pwr_mask;
+
+       writel(val, base + OWL_SPS_PG_CTL);
+
+       for (timeout = 5000; timeout > 0; timeout -= 50) {
+               val = readl(base + OWL_SPS_PG_CTL);
+               if ((val & ack_mask) == (enable ? ack_mask : 0))
+                       break;
+               udelay(50);
+       }
+       if (timeout <= 0)
+               return -ETIMEDOUT;
+
+       udelay(10);
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(owl_sps_set_pg);