1 files changed, 79 insertions, 0 deletions
diff --git a/drivers/soc/mediatek/mtk-infracfg.c b/drivers/soc/mediatek/mtk-infracfg.c
new file mode 100644
index 000000000..4a123796a
--- /dev/null
+++ b/drivers/soc/mediatek/mtk-infracfg.c
@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2015 Pengutronix, Sascha Hauer <kernel@pengutronix.de>
+ */
+
+#include <linux/export.h>
+#include <linux/jiffies.h>
+#include <linux/regmap.h>
+#include <linux/soc/mediatek/infracfg.h>
+#include <asm/processor.h>
+
+#define MTK_POLL_DELAY_US   10
+#define MTK_POLL_TIMEOUT    (jiffies_to_usecs(HZ))
+
+#define INFRA_TOPAXI_PROTECTEN		0x0220
+#define INFRA_TOPAXI_PROTECTSTA1	0x0228
+#define INFRA_TOPAXI_PROTECTEN_SET	0x0260
+#define INFRA_TOPAXI_PROTECTEN_CLR	0x0264
+
+/**
+ * mtk_infracfg_set_bus_protection - enable bus protection
+ * @infracfg: The infracfg regmap
+ * @mask: The mask containing the protection bits to be enabled.
+ * @reg_update: The boolean flag determines to set the protection bits
+ *              by regmap_update_bits with enable register(PROTECTEN) or
+ *              by regmap_write with set register(PROTECTEN_SET).
+ *
+ * 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,
+		bool reg_update)
+{
+	u32 val;
+	int ret;
+
+	if (reg_update)
+		regmap_update_bits(infracfg, INFRA_TOPAXI_PROTECTEN, mask,
+				mask);
+	else
+		regmap_write(infracfg, INFRA_TOPAXI_PROTECTEN_SET, mask);
+
+	ret = regmap_read_poll_timeout(infracfg, INFRA_TOPAXI_PROTECTSTA1,
+				       val, (val & mask) == mask,
+				       MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
+
+	return ret;
+}
+
+/**
+ * mtk_infracfg_clear_bus_protection - disable bus protection
+ * @infracfg: The infracfg regmap
+ * @mask: The mask containing the protection bits to be disabled.
+ * @reg_update: The boolean flag determines to clear the protection bits
+ *              by regmap_update_bits with enable register(PROTECTEN) or
+ *              by regmap_write with clear register(PROTECTEN_CLR).
+ *
+ * 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,
+		bool reg_update)
+{
+	int ret;
+	u32 val;
+
+	if (reg_update)
+		regmap_update_bits(infracfg, INFRA_TOPAXI_PROTECTEN, mask, 0);
+	else
+		regmap_write(infracfg, INFRA_TOPAXI_PROTECTEN_CLR, mask);
+
+	ret = regmap_read_poll_timeout(infracfg, INFRA_TOPAXI_PROTECTSTA1,
+				       val, !(val & mask),
+				       MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
+
+	return ret;
+}