These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / drivers / soc / mediatek / mtk-infracfg.c

diff --git a/kernel/drivers/soc/mediatek/mtk-infracfg.c b/kernel/drivers/soc/mediatek/mtk-infracfg.c
new file mode 100644 (file)
index 0000000..dba3055
--- /dev/null
+++ b/kernel/drivers/soc/mediatek/mtk-infracfg.c
@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 2015 Pengutronix, Sascha Hauer <kernel@pengutronix.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/export.h>
+#include <linux/jiffies.h>
+#include <linux/regmap.h>
+#include <linux/soc/mediatek/infracfg.h>
+#include <asm/processor.h>
+
+#define INFRA_TOPAXI_PROTECTEN         0x0220
+#define INFRA_TOPAXI_PROTECTSTA1       0x0228
+
+/**
+ * mtk_infracfg_set_bus_protection - enable bus protection
+ * @regmap: The infracfg regmap
+ * @mask: The mask containing the protection bits to be enabled.
+ *
+ * This function enables the bus protection bits for disabled power
+ * domains so that the system does not hang when some unit accesses the
+ * bus while in power down.
+ */
+int mtk_infracfg_set_bus_protection(struct regmap *infracfg, u32 mask)
+{
+       unsigned long expired;
+       u32 val;
+       int ret;
+
+       regmap_update_bits(infracfg, INFRA_TOPAXI_PROTECTEN, mask, mask);
+
+       expired = jiffies + HZ;
+
+       while (1) {
+               ret = regmap_read(infracfg, INFRA_TOPAXI_PROTECTSTA1, &val);
+               if (ret)
+                       return ret;
+
+               if ((val & mask) == mask)
+                       break;
+
+               cpu_relax();
+               if (time_after(jiffies, expired))
+                       return -EIO;
+       }
+
+       return 0;
+}
+
+/**
+ * mtk_infracfg_clear_bus_protection - disable bus protection
+ * @regmap: The infracfg regmap
+ * @mask: The mask containing the protection bits to be disabled.
+ *
+ * This function disables the bus protection bits previously enabled with
+ * mtk_infracfg_set_bus_protection.
+ */
+int mtk_infracfg_clear_bus_protection(struct regmap *infracfg, u32 mask)
+{
+       unsigned long expired;
+       int ret;
+
+       regmap_update_bits(infracfg, INFRA_TOPAXI_PROTECTEN, mask, 0);
+
+       expired = jiffies + HZ;
+
+       while (1) {
+               u32 val;
+
+               ret = regmap_read(infracfg, INFRA_TOPAXI_PROTECTSTA1, &val);
+               if (ret)
+                       return ret;
+
+               if (!(val & mask))
+                       break;
+
+               cpu_relax();
+               if (time_after(jiffies, expired))
+                       return -EIO;
+       }
+
+       return 0;
+}