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path: root/drivers/clk/uniphier/clk-uniphier-gate.c
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Diffstat (limited to 'drivers/clk/uniphier/clk-uniphier-gate.c')
-rw-r--r--drivers/clk/uniphier/clk-uniphier-gate.c97
1 files changed, 97 insertions, 0 deletions
diff --git a/drivers/clk/uniphier/clk-uniphier-gate.c b/drivers/clk/uniphier/clk-uniphier-gate.c
new file mode 100644
index 000000000000..49142d44446d
--- /dev/null
+++ b/drivers/clk/uniphier/clk-uniphier-gate.c
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2016 Socionext Inc.
+ * Author: Masahiro Yamada <yamada.masahiro@socionext.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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/clk-provider.h>
+#include <linux/device.h>
+#include <linux/regmap.h>
+
+#include "clk-uniphier.h"
+
+struct uniphier_clk_gate {
+ struct clk_hw hw;
+ struct regmap *regmap;
+ unsigned int reg;
+ unsigned int bit;
+};
+
+#define to_uniphier_clk_gate(_hw) \
+ container_of(_hw, struct uniphier_clk_gate, hw)
+
+static int uniphier_clk_gate_endisable(struct clk_hw *hw, int enable)
+{
+ struct uniphier_clk_gate *gate = to_uniphier_clk_gate(hw);
+
+ return regmap_write_bits(gate->regmap, gate->reg, BIT(gate->bit),
+ enable ? BIT(gate->bit) : 0);
+}
+
+static int uniphier_clk_gate_enable(struct clk_hw *hw)
+{
+ return uniphier_clk_gate_endisable(hw, 1);
+}
+
+static void uniphier_clk_gate_disable(struct clk_hw *hw)
+{
+ if (uniphier_clk_gate_endisable(hw, 0) < 0)
+ pr_warn("failed to disable clk\n");
+}
+
+static int uniphier_clk_gate_is_enabled(struct clk_hw *hw)
+{
+ struct uniphier_clk_gate *gate = to_uniphier_clk_gate(hw);
+ unsigned int val;
+
+ if (regmap_read(gate->regmap, gate->reg, &val) < 0)
+ pr_warn("is_enabled() may return wrong result\n");
+
+ return !!(val & BIT(gate->bit));
+}
+
+static const struct clk_ops uniphier_clk_gate_ops = {
+ .enable = uniphier_clk_gate_enable,
+ .disable = uniphier_clk_gate_disable,
+ .is_enabled = uniphier_clk_gate_is_enabled,
+};
+
+struct clk_hw *uniphier_clk_register_gate(struct device *dev,
+ struct regmap *regmap,
+ const char *name,
+ const struct uniphier_clk_gate_data *data)
+{
+ struct uniphier_clk_gate *gate;
+ struct clk_init_data init;
+ int ret;
+
+ gate = devm_kzalloc(dev, sizeof(*gate), GFP_KERNEL);
+ if (!gate)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = name;
+ init.ops = &uniphier_clk_gate_ops;
+ init.flags = data->parent_name ? CLK_SET_RATE_PARENT : 0;
+ init.parent_names = data->parent_name ? &data->parent_name : NULL;
+ init.num_parents = data->parent_name ? 1 : 0;
+
+ gate->regmap = regmap;
+ gate->reg = data->reg;
+ gate->bit = data->bit;
+ gate->hw.init = &init;
+
+ ret = devm_clk_hw_register(dev, &gate->hw);
+ if (ret)
+ return ERR_PTR(ret);
+
+ return &gate->hw;
+}