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Subject[PATCH V7 05/12] clk: sprd: add divider clock support
Date
This is a feature that can also be found in sprd composite clocks,
provide a bunch of helpers that can be reused later on.

Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
---
drivers/clk/sprd/Makefile | 1 +
drivers/clk/sprd/div.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++
drivers/clk/sprd/div.h | 75 +++++++++++++++++++++++++++++++++++++++
3 files changed, 166 insertions(+)
create mode 100644 drivers/clk/sprd/div.c
create mode 100644 drivers/clk/sprd/div.h

diff --git a/drivers/clk/sprd/Makefile b/drivers/clk/sprd/Makefile
index cee36b5..80e6039 100644
--- a/drivers/clk/sprd/Makefile
+++ b/drivers/clk/sprd/Makefile
@@ -3,3 +3,4 @@ obj-$(CONFIG_SPRD_COMMON_CLK) += clk-sprd.o
clk-sprd-y += common.o
clk-sprd-y += gate.o
clk-sprd-y += mux.o
+clk-sprd-y += div.o
diff --git a/drivers/clk/sprd/div.c b/drivers/clk/sprd/div.c
new file mode 100644
index 0000000..887a863
--- /dev/null
+++ b/drivers/clk/sprd/div.c
@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Spreadtrum divider clock driver
+//
+// Copyright (C) 2017 Spreadtrum, Inc.
+// Author: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
+
+#include <linux/clk-provider.h>
+
+#include "div.h"
+
+long sprd_div_helper_round_rate(struct sprd_clk_common *common,
+ const struct sprd_div_internal *div,
+ unsigned long rate,
+ unsigned long *parent_rate)
+{
+ return divider_round_rate(&common->hw, rate, parent_rate,
+ NULL, div->width, 0);
+}
+EXPORT_SYMBOL_GPL(sprd_div_helper_round_rate);
+
+static long sprd_div_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ struct sprd_div *cd = hw_to_sprd_div(hw);
+
+ return sprd_div_helper_round_rate(&cd->common, &cd->div,
+ rate, parent_rate);
+}
+
+unsigned long sprd_div_helper_recalc_rate(struct sprd_clk_common *common,
+ const struct sprd_div_internal *div,
+ unsigned long parent_rate)
+{
+ unsigned long val;
+ unsigned int reg;
+
+ regmap_read(common->regmap, common->reg, &reg);
+ val = reg >> div->shift;
+ val &= (1 << div->width) - 1;
+
+ return divider_recalc_rate(&common->hw, parent_rate, val, NULL, 0);
+}
+EXPORT_SYMBOL_GPL(sprd_div_helper_recalc_rate);
+
+static unsigned long sprd_div_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct sprd_div *cd = hw_to_sprd_div(hw);
+
+ return sprd_div_helper_recalc_rate(&cd->common, &cd->div, parent_rate);
+}
+
+int sprd_div_helper_set_rate(const struct sprd_clk_common *common,
+ const struct sprd_div_internal *div,
+ unsigned long rate,
+ unsigned long parent_rate)
+{
+ unsigned long val;
+ unsigned int reg;
+
+ val = divider_get_val(rate, parent_rate, NULL,
+ div->width, 0);
+
+ regmap_read(common->regmap, common->reg, &reg);
+ reg &= ~GENMASK(div->width + div->shift - 1, div->shift);
+
+ regmap_write(common->regmap, common->reg,
+ reg | (val << div->shift));
+
+ return 0;
+
+}
+EXPORT_SYMBOL_GPL(sprd_div_helper_set_rate);
+
+static int sprd_div_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct sprd_div *cd = hw_to_sprd_div(hw);
+
+ return sprd_div_helper_set_rate(&cd->common, &cd->div,
+ rate, parent_rate);
+}
+
+const struct clk_ops sprd_div_ops = {
+ .recalc_rate = sprd_div_recalc_rate,
+ .round_rate = sprd_div_round_rate,
+ .set_rate = sprd_div_set_rate,
+};
+EXPORT_SYMBOL_GPL(sprd_div_ops);
diff --git a/drivers/clk/sprd/div.h b/drivers/clk/sprd/div.h
new file mode 100644
index 0000000..b3033d2
--- /dev/null
+++ b/drivers/clk/sprd/div.h
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Spreadtrum divider clock driver
+//
+// Copyright (C) 2017 Spreadtrum, Inc.
+// Author: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
+
+#ifndef _SPRD_DIV_H_
+#define _SPRD_DIV_H_
+
+#include "common.h"
+
+/**
+ * struct sprd_div_internal - Internal divider description
+ * @shift: Bit offset of the divider in its register
+ * @width: Width of the divider field in its register
+ *
+ * That structure represents a single divider, and is meant to be
+ * embedded in other structures representing the various clock
+ * classes.
+ */
+struct sprd_div_internal {
+ u8 shift;
+ u8 width;
+};
+
+#define _SPRD_DIV_CLK(_shift, _width) \
+ { \
+ .shift = _shift, \
+ .width = _width, \
+ }
+
+struct sprd_div {
+ struct sprd_div_internal div;
+ struct sprd_clk_common common;
+};
+
+#define SPRD_DIV_CLK(_struct, _name, _parent, _reg, \
+ _shift, _width, _flags) \
+ struct sprd_div _struct = { \
+ .div = _SPRD_DIV_CLK(_shift, _width), \
+ .common = { \
+ .regmap = NULL, \
+ .reg = _reg, \
+ .hw.init = CLK_HW_INIT(_name, \
+ _parent, \
+ &sprd_div_ops, \
+ _flags), \
+ } \
+ }
+
+static inline struct sprd_div *hw_to_sprd_div(const struct clk_hw *hw)
+{
+ struct sprd_clk_common *common = hw_to_sprd_clk_common(hw);
+
+ return container_of(common, struct sprd_div, common);
+}
+
+long sprd_div_helper_round_rate(struct sprd_clk_common *common,
+ const struct sprd_div_internal *div,
+ unsigned long rate,
+ unsigned long *parent_rate);
+
+unsigned long sprd_div_helper_recalc_rate(struct sprd_clk_common *common,
+ const struct sprd_div_internal *div,
+ unsigned long parent_rate);
+
+int sprd_div_helper_set_rate(const struct sprd_clk_common *common,
+ const struct sprd_div_internal *div,
+ unsigned long rate,
+ unsigned long parent_rate);
+
+extern const struct clk_ops sprd_div_ops;
+
+#endif /* _SPRD_DIV_H_ */
--
2.7.4
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