Hi,
On 02/11/17 06:56, Chunyan Zhang wrote:
Some clocks on the Spreadtrum's SoCs are just simple gates. Add
support for those clocks.
Signed-off-by: Chunyan Zhang <chunyan.zhang@xxxxxxxxxxxxxx>
---
drivers/clk/sprd/Makefile | 1 +
drivers/clk/sprd/gate.c | 106 ++++++++++++++++++++++++++++++++++++++++++++++
drivers/clk/sprd/gate.h | 54 +++++++++++++++++++++++
3 files changed, 161 insertions(+)
create mode 100644 drivers/clk/sprd/gate.c
create mode 100644 drivers/clk/sprd/gate.h
diff --git a/drivers/clk/sprd/Makefile b/drivers/clk/sprd/Makefile
index 74f4b80..8cd5592 100644
--- a/drivers/clk/sprd/Makefile
+++ b/drivers/clk/sprd/Makefile
@@ -1,3 +1,4 @@
obj-$(CONFIG_SPRD_COMMON_CLK) += clk-sprd.o
clk-sprd-y += common.o
+clk-sprd-y += gate.o
diff --git a/drivers/clk/sprd/gate.c b/drivers/clk/sprd/gate.c
new file mode 100644
index 0000000..831ef81
--- /dev/null
+++ b/drivers/clk/sprd/gate.c
@@ -0,0 +1,106 @@
+/*
+ * Spreadtrum gate clock driver
+ *
+ * Copyright (C) 2017 Spreadtrum, Inc.
+ * Author: Chunyan Zhang <chunyan.zhang@xxxxxxxxxxxxxx>
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/regmap.h>
+
+#include "gate.h"
+
+DEFINE_SPINLOCK(sprd_gate_lock);
+EXPORT_SYMBOL_GPL(sprd_gate_lock);
+
+static void sprd_gate_endisable(const struct sprd_gate *sg, u32 en)
+{
+ const struct sprd_clk_common *common = &sg->common;
+ unsigned long flags = 0;
+ unsigned int reg;
+ int set = sg->flags & CLK_GATE_SET_TO_DISABLE ? 1 : 0;
+
+ set ^= en;
+
+ spin_lock_irqsave(common->lock, flags);
+
+ sprd_regmap_read(common->regmap, common->reg, ®);
+
+ if (set)
+ reg |= sg->op_bit;
+ else
+ reg &= ~sg->op_bit;
+
+ sprd_regmap_write(common->regmap, common->reg, reg);
+
+ spin_unlock_irqrestore(common->lock, flags);
+}
+
+static void clk_sc_gate_endisable(const struct sprd_gate *sg, u32 en)
+{
+ const struct sprd_clk_common *common = &sg->common;
+ unsigned long flags = 0;
+ int set = sg->flags & CLK_GATE_SET_TO_DISABLE ? 1 : 0;
+ unsigned int offset;
+
+ set ^= en;
+
+ /*
+ * Each set/clear gate clock has three registers:
+ * common->reg - base register
+ * common->reg + offset - set register
+ * common->reg + 2 * offset - clear register
+ */
+ offset = set ? sg->sc_offset : sg->sc_offset * 2;
+
+ spin_lock_irqsave(common->lock, flags);
+ sprd_regmap_write(common->regmap, common->reg + offset, sg->op_bit);
+ spin_unlock_irqrestore(common->lock, flags);
+}
+
+static void sprd_gate_disable(struct clk_hw *hw)
+{
+ struct sprd_gate *sg = hw_to_sprd_gate(hw);
+
+ if (sg->sc_offset)
+ clk_sc_gate_endisable(sg, 0);
+ else
+ sprd_gate_endisable(sg, 0);
+}
+
+static int sprd_gate_enable(struct clk_hw *hw)
+{
+ struct sprd_gate *sg = hw_to_sprd_gate(hw);
+
+ if (sg->sc_offset)
+ clk_sc_gate_endisable(sg, 1);
+ else
+ sprd_gate_endisable(sg, 1);
+
+ return 0;
+}
+
+static int sprd_gate_is_enabled(struct clk_hw *hw)
+{
+ struct sprd_gate *sg = hw_to_sprd_gate(hw);
+ struct sprd_clk_common *common = &sg->common;
+ unsigned int reg;
+
+ sprd_regmap_read(common->regmap, common->reg, ®);
+
+ if (sg->flags & CLK_GATE_SET_TO_DISABLE)
+ reg ^= sg->op_bit;
+
+ reg &= sg->op_bit;
+
+ return reg ? 1 : 0;
+}
+
+const struct clk_ops sprd_gate_ops = {
+ .disable = sprd_gate_disable,
+ .enable = sprd_gate_enable,
+ .is_enabled = sprd_gate_is_enabled,
+};
+EXPORT_SYMBOL_GPL(sprd_gate_ops);
I think it would be better to have a set of ops for each mode,
sprd_gate_ops and sprd_sc_gate_ops rather than have each function decide
whether it should use set/clear registers or the base registers.
So you can have a macro SPRD_GATE_CLK that doesn't take an sc_offet and
selects the sprd_gate_ops and another one that SPRD_SC_GATE_CLK using
sprd_sc_gate_ops that takes the sc_offset as parameter.
Also, I feel keeping enable/disable function separate would be nicer
instead of having "endisable" functions.
Cheers,
diff --git a/drivers/clk/sprd/gate.h b/drivers/clk/sprd/gate.h
new file mode 100644
index 0000000..5aeb53c
--- /dev/null
+++ b/drivers/clk/sprd/gate.h
@@ -0,0 +1,54 @@
+/*
+ * Spreadtrum gate clock driver
+ *
+ * Copyright (C) 2017 Spreadtrum, Inc.
+ * Author: Chunyan Zhang <chunyan.zhang@xxxxxxxxxxxxxx>
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#ifndef _SPRD_GATE_H_
+#define _SPRD_GATE_H_
+
+#include "common.h"
+
+struct sprd_gate {
+ u32 op_bit;
+ u16 flags;
+ u16 sc_offset;
+
+ struct sprd_clk_common common;
+};
+
+#define SPRD_GATE_CLK(_struct, _name, _parent, _reg, _sc_offset, \
+ _op_bit, _flags, _gate_flags) \
+ struct sprd_gate _struct = { \
+ .op_bit = _op_bit, \
+ .sc_offset = _sc_offset, \
+ .flags = _gate_flags, \
+ .common = { \
+ .regmap = NULL, \
+ .reg = _reg, \
+ .lock = &sprd_gate_lock, \
+ .hw.init = CLK_HW_INIT(_name, \
+ _parent, \
+ &sprd_gate_ops, \
+ _flags), \
+ } \
+ }
+
+static inline struct sprd_gate *hw_to_sprd_gate(const struct clk_hw *hw)
+{
+ struct sprd_clk_common *common = hw_to_sprd_clk_common(hw);
+
+ return container_of(common, struct sprd_gate, common);
+}
+
+void sprd_gate_helper_disable(struct sprd_clk_common *common, u32 gate);
+int sprd_gate_helper_enable(struct sprd_clk_common *common, u32 gate);
+int sprd_gate_helper_is_enabled(struct sprd_clk_common *common, u32 gate);
+
+extern const struct clk_ops sprd_gate_ops;
+extern spinlock_t sprd_gate_lock;
+
+#endif /* _SPRD_GATE_H_ */
--
Julien Thierry
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