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Subject[PATCH v6 07/11] clk: actions: Add factor clock support
Date
Add support for Actions Semi factor clock together with
helper functions to be used in composite clock.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
drivers/clk/actions/Makefile | 1 +
drivers/clk/actions/owl-factor.c | 222 +++++++++++++++++++++++++++++++++++++++
drivers/clk/actions/owl-factor.h | 83 +++++++++++++++
3 files changed, 306 insertions(+)
create mode 100644 drivers/clk/actions/owl-factor.c
create mode 100644 drivers/clk/actions/owl-factor.h

diff --git a/drivers/clk/actions/Makefile b/drivers/clk/actions/Makefile
index 5ce75df57e1a..994357fa560b 100644
--- a/drivers/clk/actions/Makefile
+++ b/drivers/clk/actions/Makefile
@@ -4,3 +4,4 @@ clk-owl-y += owl-common.o
clk-owl-y += owl-gate.o
clk-owl-y += owl-mux.o
clk-owl-y += owl-divider.o
+clk-owl-y += owl-factor.o
diff --git a/drivers/clk/actions/owl-factor.c b/drivers/clk/actions/owl-factor.c
new file mode 100644
index 000000000000..317d4a9e112e
--- /dev/null
+++ b/drivers/clk/actions/owl-factor.c
@@ -0,0 +1,222 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// OWL factor clock driver
+//
+// Copyright (c) 2014 Actions Semi Inc.
+// Author: David Liu <liuwei@actions-semi.com>
+//
+// Copyright (c) 2018 Linaro Ltd.
+// Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
+
+#include <linux/clk-provider.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#include "owl-factor.h"
+
+static unsigned int _get_table_maxval(const struct clk_factor_table *table)
+{
+ unsigned int maxval = 0;
+ const struct clk_factor_table *clkt;
+
+ for (clkt = table; clkt->div; clkt++)
+ if (clkt->val > maxval)
+ maxval = clkt->val;
+ return maxval;
+}
+
+static int _get_table_div_mul(const struct clk_factor_table *table,
+ unsigned int val, unsigned int *mul, unsigned int *div)
+{
+ const struct clk_factor_table *clkt;
+
+ for (clkt = table; clkt->div; clkt++) {
+ if (clkt->val == val) {
+ *mul = clkt->mul;
+ *div = clkt->div;
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+static unsigned int _get_table_val(const struct clk_factor_table *table,
+ unsigned long rate, unsigned long parent_rate)
+{
+ const struct clk_factor_table *clkt;
+ int val = -1;
+ u64 calc_rate;
+
+ for (clkt = table; clkt->div; clkt++) {
+ calc_rate = parent_rate * clkt->mul;
+ do_div(calc_rate, clkt->div);
+
+ if ((unsigned long)calc_rate <= rate) {
+ val = clkt->val;
+ break;
+ }
+ }
+
+ if (val == -1)
+ val = _get_table_maxval(table);
+
+ return val;
+}
+
+static int clk_val_best(struct clk_hw *hw, unsigned long rate,
+ unsigned long *best_parent_rate)
+{
+ struct owl_factor *factor = hw_to_owl_factor(hw);
+ struct owl_factor_hw *factor_hw = &factor->factor_hw;
+ const struct clk_factor_table *clkt = factor_hw->table;
+ unsigned long parent_rate, try_parent_rate, best = 0, cur_rate;
+ unsigned long parent_rate_saved = *best_parent_rate;
+ int bestval = 0;
+
+ if (!rate)
+ rate = 1;
+
+ if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) {
+ parent_rate = *best_parent_rate;
+ bestval = _get_table_val(clkt, rate, parent_rate);
+ return bestval;
+ }
+
+ for (clkt = factor_hw->table; clkt->div; clkt++) {
+ try_parent_rate = rate * clkt->div / clkt->mul;
+
+ if (try_parent_rate == parent_rate_saved) {
+ pr_debug("%s: [%d %d %d] found try_parent_rate %ld\n",
+ __func__, clkt->val, clkt->mul, clkt->div,
+ try_parent_rate);
+ /*
+ * It's the most ideal case if the requested rate can be
+ * divided from parent clock without any need to change
+ * parent rate, so return the divider immediately.
+ */
+ *best_parent_rate = parent_rate_saved;
+ return clkt->val;
+ }
+
+ parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw),
+ try_parent_rate);
+ cur_rate = DIV_ROUND_UP(parent_rate, clkt->div) * clkt->mul;
+ if (cur_rate <= rate && cur_rate > best) {
+ bestval = clkt->val;
+ best = cur_rate;
+ *best_parent_rate = parent_rate;
+ }
+ }
+
+ if (!bestval) {
+ bestval = _get_table_maxval(clkt);
+ *best_parent_rate = clk_hw_round_rate(
+ clk_hw_get_parent(hw), 1);
+ }
+
+ return bestval;
+}
+
+long owl_factor_helper_round_rate(struct owl_clk_common *common,
+ const struct owl_factor_hw *factor_hw,
+ unsigned long rate,
+ unsigned long *parent_rate)
+{
+ const struct clk_factor_table *clkt = factor_hw->table;
+ unsigned int val, mul = 0, div = 1;
+
+ val = clk_val_best(&common->hw, rate, parent_rate);
+ _get_table_div_mul(clkt, val, &mul, &div);
+
+ return *parent_rate * mul / div;
+}
+
+static long owl_factor_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ struct owl_factor *factor = hw_to_owl_factor(hw);
+ struct owl_factor_hw *factor_hw = &factor->factor_hw;
+
+ return owl_factor_helper_round_rate(&factor->common, factor_hw,
+ rate, parent_rate);
+}
+
+unsigned long owl_factor_helper_recalc_rate(struct owl_clk_common *common,
+ const struct owl_factor_hw *factor_hw,
+ unsigned long parent_rate)
+{
+ const struct clk_factor_table *clkt = factor_hw->table;
+ unsigned long long int rate;
+ u32 reg, val, mul, div;
+
+ div = 0;
+ mul = 0;
+
+ regmap_read(common->regmap, factor_hw->reg, &reg);
+
+ val = reg >> factor_hw->shift;
+ val &= div_mask(factor_hw);
+
+ _get_table_div_mul(clkt, val, &mul, &div);
+ if (!div) {
+ WARN(!(factor_hw->fct_flags & CLK_DIVIDER_ALLOW_ZERO),
+ "%s: Zero divisor and CLK_DIVIDER_ALLOW_ZERO not set\n",
+ __clk_get_name(common->hw.clk));
+ return parent_rate;
+ }
+
+ rate = (unsigned long long int)parent_rate * mul;
+ do_div(rate, div);
+
+ return rate;
+}
+
+static unsigned long owl_factor_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct owl_factor *factor = hw_to_owl_factor(hw);
+ struct owl_factor_hw *factor_hw = &factor->factor_hw;
+ struct owl_clk_common *common = &factor->common;
+
+ return owl_factor_helper_recalc_rate(common, factor_hw, parent_rate);
+}
+
+int owl_factor_helper_set_rate(const struct owl_clk_common *common,
+ const struct owl_factor_hw *factor_hw,
+ unsigned long rate,
+ unsigned long parent_rate)
+{
+ u32 val, reg;
+
+ val = _get_table_val(factor_hw->table, rate, parent_rate);
+
+ if (val > div_mask(factor_hw))
+ val = div_mask(factor_hw);
+
+ regmap_read(common->regmap, factor_hw->reg, &reg);
+
+ reg &= ~(div_mask(factor_hw) << factor_hw->shift);
+ reg |= val << factor_hw->shift;
+
+ regmap_write(common->regmap, factor_hw->reg, reg);
+
+ return 0;
+}
+
+static int owl_factor_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct owl_factor *factor = hw_to_owl_factor(hw);
+ struct owl_factor_hw *factor_hw = &factor->factor_hw;
+ struct owl_clk_common *common = &factor->common;
+
+ return owl_factor_helper_set_rate(common, factor_hw,
+ rate, parent_rate);
+}
+
+const struct clk_ops owl_factor_ops = {
+ .round_rate = owl_factor_round_rate,
+ .recalc_rate = owl_factor_recalc_rate,
+ .set_rate = owl_factor_set_rate,
+};
diff --git a/drivers/clk/actions/owl-factor.h b/drivers/clk/actions/owl-factor.h
new file mode 100644
index 000000000000..f1a7ffe896e1
--- /dev/null
+++ b/drivers/clk/actions/owl-factor.h
@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// OWL factor clock driver
+//
+// Copyright (c) 2014 Actions Semi Inc.
+// Author: David Liu <liuwei@actions-semi.com>
+//
+// Copyright (c) 2018 Linaro Ltd.
+// Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
+
+#ifndef _OWL_FACTOR_H_
+#define _OWL_FACTOR_H_
+
+#include "owl-common.h"
+
+struct clk_factor_table {
+ unsigned int val;
+ unsigned int mul;
+ unsigned int div;
+};
+
+struct owl_factor_hw {
+ u32 reg;
+ u8 shift;
+ u8 width;
+ u8 fct_flags;
+ struct clk_factor_table *table;
+};
+
+struct owl_factor {
+ struct owl_factor_hw factor_hw;
+ struct owl_clk_common common;
+};
+
+#define OWL_FACTOR_HW(_reg, _shift, _width, _fct_flags, _table) \
+ { \
+ .reg = _reg, \
+ .shift = _shift, \
+ .width = _width, \
+ .fct_flags = _fct_flags, \
+ .table = _table, \
+ }
+
+#define OWL_FACTOR(_struct, _name, _parent, _reg, \
+ _shift, _width, _table, _fct_flags, _flags) \
+ struct owl_factor _struct = { \
+ .factor_hw = OWL_FACTOR_HW(_reg, _shift, \
+ _width, _fct_flags, _table), \
+ .common = { \
+ .regmap = NULL, \
+ .hw.init = CLK_HW_INIT(_name, \
+ _parent, \
+ &owl_factor_ops, \
+ _flags), \
+ }, \
+ }
+
+#define div_mask(d) ((1 << ((d)->width)) - 1)
+
+static inline struct owl_factor *hw_to_owl_factor(const struct clk_hw *hw)
+{
+ struct owl_clk_common *common = hw_to_owl_clk_common(hw);
+
+ return container_of(common, struct owl_factor, common);
+}
+
+long owl_factor_helper_round_rate(struct owl_clk_common *common,
+ const struct owl_factor_hw *factor_hw,
+ unsigned long rate,
+ unsigned long *parent_rate);
+
+unsigned long owl_factor_helper_recalc_rate(struct owl_clk_common *common,
+ const struct owl_factor_hw *factor_hw,
+ unsigned long parent_rate);
+
+int owl_factor_helper_set_rate(const struct owl_clk_common *common,
+ const struct owl_factor_hw *factor_hw,
+ unsigned long rate,
+ unsigned long parent_rate);
+
+extern const struct clk_ops owl_factor_ops;
+
+#endif /* _OWL_FACTOR_H_ */
--
2.14.1
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