clk: sunxi-ng: Add gate clock support

Some clocks in the Allwinner SoCs clocks unit are just simple gates. Add
support for those clocks.

Since it's a feature that can also be found in more complex clocks, provide
a bunch of helpers that can be reused later on.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20160629190535.11855-5-maxime.ripard@free-electrons.com

diff --git a/drivers/clk/sunxi-ng/Kconfig b/drivers/clk/sunxi-ng/Kconfig
index 3d117d7a3621ee4415c57e80ae0be27e529f4b11..2f135c8a61b681872f21896663d5342f81f1115c 100644 (file)
--- a/drivers/clk/sunxi-ng/Kconfig
+++ b/drivers/clk/sunxi-ng/Kconfig
@@ -9,4 +9,7 @@ if SUNXI_CCU
 config SUNXI_CCU_FRAC
        bool
 
+config SUNXI_CCU_GATE
+       bool
+
 endif

diff --git a/drivers/clk/sunxi-ng/Makefile b/drivers/clk/sunxi-ng/Makefile
index 46f417cb682a7071f00c6d49a48c67b64702ac99..48b885f2d8ff1d9e89431fca9d2da91d3c5d3c14 100644 (file)
--- a/drivers/clk/sunxi-ng/Makefile
+++ b/drivers/clk/sunxi-ng/Makefile
@@ -4,3 +4,4 @@ obj-$(CONFIG_SUNXI_CCU)         += ccu_reset.o
 
 # Base clock types
 obj-$(CONFIG_SUNXI_CCU_FRAC)   += ccu_frac.o
+obj-$(CONFIG_SUNXI_CCU_GATE)   += ccu_gate.o

diff --git a/drivers/clk/sunxi-ng/ccu_gate.c b/drivers/clk/sunxi-ng/ccu_gate.c
new file mode 100644 (file)
index 0000000..8a81f9d
--- /dev/null
+++ b/drivers/clk/sunxi-ng/ccu_gate.c
@@ -0,0 +1,82 @@
+/*
+ * Copyright (C) 2016 Maxime Ripard
+ * Maxime Ripard <maxime.ripard@free-electrons.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.
+ */
+
+#include <linux/clk-provider.h>
+
+#include "ccu_gate.h"
+
+void ccu_gate_helper_disable(struct ccu_common *common, u32 gate)
+{
+       unsigned long flags;
+       u32 reg;
+
+       if (!gate)
+               return;
+
+       spin_lock_irqsave(common->lock, flags);
+
+       reg = readl(common->base + common->reg);
+       writel(reg & ~gate, common->base + common->reg);
+
+       spin_unlock_irqrestore(common->lock, flags);
+}
+
+static void ccu_gate_disable(struct clk_hw *hw)
+{
+       struct ccu_gate *cg = hw_to_ccu_gate(hw);
+
+       return ccu_gate_helper_disable(&cg->common, cg->enable);
+}
+
+int ccu_gate_helper_enable(struct ccu_common *common, u32 gate)
+{
+       unsigned long flags;
+       u32 reg;
+
+       if (!gate)
+               return 0;
+
+       spin_lock_irqsave(common->lock, flags);
+
+       reg = readl(common->base + common->reg);
+       writel(reg | gate, common->base + common->reg);
+
+       spin_unlock_irqrestore(common->lock, flags);
+
+       return 0;
+}
+
+static int ccu_gate_enable(struct clk_hw *hw)
+{
+       struct ccu_gate *cg = hw_to_ccu_gate(hw);
+
+       return ccu_gate_helper_enable(&cg->common, cg->enable);
+}
+
+int ccu_gate_helper_is_enabled(struct ccu_common *common, u32 gate)
+{
+       if (!gate)
+               return 1;
+
+       return readl(common->base + common->reg) & gate;
+}
+
+static int ccu_gate_is_enabled(struct clk_hw *hw)
+{
+       struct ccu_gate *cg = hw_to_ccu_gate(hw);
+
+       return ccu_gate_helper_is_enabled(&cg->common, cg->enable);
+}
+
+const struct clk_ops ccu_gate_ops = {
+       .disable        = ccu_gate_disable,
+       .enable         = ccu_gate_enable,
+       .is_enabled     = ccu_gate_is_enabled,
+};

diff --git a/drivers/clk/sunxi-ng/ccu_gate.h b/drivers/clk/sunxi-ng/ccu_gate.h
new file mode 100644 (file)
index 0000000..4466169
--- /dev/null
+++ b/drivers/clk/sunxi-ng/ccu_gate.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2016 Maxime Ripard. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ */
+
+#ifndef _CCU_GATE_H_
+#define _CCU_GATE_H_
+
+#include <linux/clk-provider.h>
+
+#include "ccu_common.h"
+
+struct ccu_gate {
+       u32                     enable;
+
+       struct ccu_common       common;
+};
+
+#define SUNXI_CCU_GATE(_struct, _name, _parent, _reg, _gate, _flags)   \
+       struct ccu_gate _struct = {                                     \
+               .enable = _gate,                                        \
+               .common = {                                             \
+                       .reg            = _reg,                         \
+                       .hw.init        = CLK_HW_INIT(_name,            \
+                                                     _parent,          \
+                                                     &ccu_gate_ops,    \
+                                                     _flags),          \
+               }                                                       \
+       }
+
+static inline struct ccu_gate *hw_to_ccu_gate(struct clk_hw *hw)
+{
+       struct ccu_common *common = hw_to_ccu_common(hw);
+
+       return container_of(common, struct ccu_gate, common);
+}
+
+void ccu_gate_helper_disable(struct ccu_common *common, u32 gate);
+int ccu_gate_helper_enable(struct ccu_common *common, u32 gate);
+int ccu_gate_helper_is_enabled(struct ccu_common *common, u32 gate);
+
+extern const struct clk_ops ccu_gate_ops;
+
+#endif /* _CCU_GATE_H_ */