[PATCH 7/9] clk: actions: Add Actions Semi Owl SoCs Reset Management Unit support

Manivannan Sadhasivam
2018-07-27T18:48:12Z

Add Reset Management Unit (RMU) support for Actions Semi Owl SoCs.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
drivers/clk/actions/Kconfig | 1 +
drivers/clk/actions/Makefile | 1 +
drivers/clk/actions/owl-common.h | 2 +
drivers/clk/actions/owl-reset.c | 72 ++++++++++++++++++++++++++++++++
drivers/clk/actions/owl-reset.h | 32 ++++++++++++++
5 files changed, 108 insertions(+)
create mode 100644 drivers/clk/actions/owl-reset.c
create mode 100644 drivers/clk/actions/owl-reset.h

diff --git a/drivers/clk/actions/Kconfig b/drivers/clk/actions/Kconfig
index dc38c85a4833..04f0a6355726 100644
--- a/drivers/clk/actions/Kconfig
+++ b/drivers/clk/actions/Kconfig
@@ -2,6 +2,7 @@ config CLK_ACTIONS
bool "Clock driver for Actions Semi SoCs"
depends on ARCH_ACTIONS || COMPILE_TEST
select REGMAP_MMIO
+ select RESET_CONTROLLER
default ARCH_ACTIONS

if CLK_ACTIONS
diff --git a/drivers/clk/actions/Makefile b/drivers/clk/actions/Makefile
index 78c17d56f991..ccfdf9781cef 100644
--- a/drivers/clk/actions/Makefile
+++ b/drivers/clk/actions/Makefile
@@ -7,6 +7,7 @@ clk-owl-y += owl-divider.o
clk-owl-y += owl-factor.o
clk-owl-y += owl-composite.o
clk-owl-y += owl-pll.o
+clk-owl-y += owl-reset.o

# SoC support
obj-$(CONFIG_CLK_OWL_S700) += owl-s700.o
diff --git a/drivers/clk/actions/owl-common.h b/drivers/clk/actions/owl-common.h
index 56f01f7774aa..4dc7f286831f 100644
--- a/drivers/clk/actions/owl-common.h
+++ b/drivers/clk/actions/owl-common.h
@@ -26,6 +26,8 @@ struct owl_clk_desc {
struct owl_clk_common **clks;
unsigned long num_clks;
struct clk_hw_onecell_data *hw_clks;
+ struct owl_reset_map *resets;
+ unsigned long num_resets;
struct regmap *regmap;
};

diff --git a/drivers/clk/actions/owl-reset.c b/drivers/clk/actions/owl-reset.c
new file mode 100644
index 000000000000..91b161cc68de
--- /dev/null
+++ b/drivers/clk/actions/owl-reset.c
@@ -0,0 +1,72 @@
+// 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/io.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];
+ u32 reg;
+
+ regmap_read(reset->regmap, map->reg, &reg);
+ regmap_write(reset->regmap, map->reg, reg & ~map->bit);
+
+ return 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];
+ u32 reg;
+
+ regmap_read(reset->regmap, map->reg, &reg);
+ regmap_write(reset->regmap, map->reg, reg | map->bit);
+
+ return 0;
+}
+
+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;
+
+ regmap_read(reset->regmap, map->reg, &reg);
+
+ /*
+ * 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,
+};
diff --git a/drivers/clk/actions/owl-reset.h b/drivers/clk/actions/owl-reset.h
new file mode 100644
index 000000000000..1a5e987ba99b
--- /dev/null
+++ b/drivers/clk/actions/owl-reset.h
@@ -0,0 +1,32 @@
+// 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>
+
+#ifndef _OWL_RESET_H_
+#define _OWL_RESET_H_
+
+#include <linux/reset-controller.h>
+#include <linux/spinlock.h>
+
+struct owl_reset_map {
+ u16 reg;
+ u32 bit;
+};
+
+struct owl_reset {
+ struct reset_controller_dev rcdev;
+ struct owl_reset_map *reset_map;
+ struct regmap *regmap;
+};
+
+static inline struct owl_reset *to_owl_reset(struct reset_controller_dev *rcdev)
+{
+ return container_of(rcdev, struct owl_reset, rcdev);
+}
+
+extern const struct reset_control_ops owl_reset_ops;
+
+#endif /* _OWL_RESET_H_ */
--
2.17.1