clk: actions: Add Actions Semi Owl SoCs Reset Management Unit support

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

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

diff --git a/drivers/clk/actions/Kconfig b/drivers/clk/actions/Kconfig
index dc38c85..04f0a63 100644 (file)
--- 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 78c17d5..ccfdf97 100644 (file)
--- 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 56f01f7..5a866a8 100644 (file)
--- 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;
+       const 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 (file)
index 0000000..203f8f3
--- /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,
+};

diff --git a/drivers/clk/actions/owl-reset.h b/drivers/clk/actions/owl-reset.h
new file mode 100644 (file)
index 0000000..10f5774
--- /dev/null
+++ b/drivers/clk/actions/owl-reset.h
@@ -0,0 +1,31 @@
+// 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>
+
+struct owl_reset_map {
+       u32     reg;
+       u32     bit;
+};
+
+struct owl_reset {
+       struct reset_controller_dev     rcdev;
+       const 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_ */