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Diffstat (limited to 'drivers/clk/actions/owl-reset.c')
-rw-r--r--drivers/clk/actions/owl-reset.c66
1 files changed, 66 insertions, 0 deletions
diff --git a/drivers/clk/actions/owl-reset.c b/drivers/clk/actions/owl-reset.c
new file mode 100644
index 000000000..203f8f34a
--- /dev/null
+++ b/drivers/clk/actions/owl-reset.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+//
+// Actions Semi Owl SoCs Reset Management Unit driver
+//
+// Copyright (c) 2018 Linaro Ltd.
+// Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
+
+#include <linux/delay.h>
+#include <linux/regmap.h>
+#include <linux/reset-controller.h>
+
+#include "owl-reset.h"
+
+static int owl_reset_assert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct owl_reset *reset = to_owl_reset(rcdev);
+ const struct owl_reset_map *map = &reset->reset_map[id];
+
+ return regmap_update_bits(reset->regmap, map->reg, map->bit, 0);
+}
+
+static int owl_reset_deassert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct owl_reset *reset = to_owl_reset(rcdev);
+ const struct owl_reset_map *map = &reset->reset_map[id];
+
+ return regmap_update_bits(reset->regmap, map->reg, map->bit, map->bit);
+}
+
+static int owl_reset_reset(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ owl_reset_assert(rcdev, id);
+ udelay(1);
+ owl_reset_deassert(rcdev, id);
+
+ return 0;
+}
+
+static int owl_reset_status(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct owl_reset *reset = to_owl_reset(rcdev);
+ const struct owl_reset_map *map = &reset->reset_map[id];
+ u32 reg;
+ int ret;
+
+ ret = regmap_read(reset->regmap, map->reg, &reg);
+ if (ret)
+ return ret;
+
+ /*
+ * The reset control API expects 0 if reset is not asserted,
+ * which is the opposite of what our hardware uses.
+ */
+ return !(map->bit & reg);
+}
+
+const struct reset_control_ops owl_reset_ops = {
+ .assert = owl_reset_assert,
+ .deassert = owl_reset_deassert,
+ .reset = owl_reset_reset,
+ .status = owl_reset_status,
+};