[PATCH 06/16] clk: sunxi-ng: Add divider table clock
From: Chen-Yu Tsai <hidden>
Date: 2016-05-21 16:30:19
Also in:
linux-clk
Hi, On Mon, May 9, 2016 at 4:01 AM, Maxime Ripard [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Add support for clocks based on a divider tables. Signed-off-by: Maxime Ripard <redacted> --- drivers/clk/sunxi-ng/Makefile | 1 + drivers/clk/sunxi-ng/ccu_div_table.c | 117 +++++++++++++++++++++++++++++++++++ drivers/clk/sunxi-ng/ccu_div_table.h | 75 ++++++++++++++++++++++ 3 files changed, 193 insertions(+) create mode 100644 drivers/clk/sunxi-ng/ccu_div_table.c create mode 100644 drivers/clk/sunxi-ng/ccu_div_table.hdiff --git a/drivers/clk/sunxi-ng/Makefile b/drivers/clk/sunxi-ng/Makefile index aa5c411ff8ea..f20c6c8f217c 100644 --- a/drivers/clk/sunxi-ng/Makefile +++ b/drivers/clk/sunxi-ng/Makefile@@ -1,6 +1,7 @@ obj-y += ccu_common.o obj-y += ccu_reset.o +obj-y += ccu_div_table.o obj-y += ccu_fixed_factor.o obj-y += ccu_gate.o obj-y += ccu_mux.odiff --git a/drivers/clk/sunxi-ng/ccu_div_table.c b/drivers/clk/sunxi-ng/ccu_div_table.c new file mode 100644 index 000000000000..cbfff0bd47e3 --- /dev/null +++ b/drivers/clk/sunxi-ng/ccu_div_table.c@@ -0,0 +1,117 @@ +/* + * 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_div_table.h" +#include "ccu_gate.h" + +static void ccu_div_table_find_best(unsigned long parent, unsigned long rate, + struct ccu_div_table *ct, + unsigned int *index) +{ + unsigned long best_rate = 0; + unsigned int best_index = 0; + unsigned int _index; + + for (_index = 0; _index <= ct->num_divs; _index++) { + unsigned long tmp_rate = parent / ct->table[_index]; + + if (tmp_rate > rate) + continue; + + if ((rate - tmp_rate) < (rate - best_rate)) { + best_rate = tmp_rate; + best_index = _index; + } + } + + *index = best_index; +}
You can drop this function and use the CCF helpers (mentioned below) instead.
+
+static void ccu_div_table_disable(struct clk_hw *hw)
+{
+ struct ccu_div_table *ct = hw_to_ccu_div_table(hw);
+
+ return ccu_gate_helper_disable(&ct->common, ct->enable);
+}
+
+static int ccu_div_table_enable(struct clk_hw *hw)
+{
+ struct ccu_div_table *ct = hw_to_ccu_div_table(hw);
+
+ return ccu_gate_helper_enable(&ct->common, ct->enable);
+}
+
+static int ccu_div_table_is_enabled(struct clk_hw *hw)
+{
+ struct ccu_div_table *ct = hw_to_ccu_div_table(hw);
+
+ return ccu_gate_helper_is_enabled(&ct->common, ct->enable);
+}
+
+static unsigned long ccu_div_table_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct ccu_div_table *ct = hw_to_ccu_div_table(hw);
+ unsigned long div;
+ u32 reg;
+
+ reg = readl(ct->common.base + ct->common.reg);
+
+ div = reg >> ct->div.shift;
+ div &= (1 << ct->div.width) - 1;
+
+ return parent_rate / ct->table[div];CCF provides divider_recalc_rate().
+}
+
+static long ccu_div_table_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ struct ccu_div_table *ct = hw_to_ccu_div_table(hw);
+ unsigned int index;
+
+ ccu_div_table_find_best(*parent_rate, rate,
+ ct, &index);
+
+ return *parent_rate / ct->table[index];CCF provides divider_round_rate().
+}
+
+static int ccu_div_table_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct ccu_div_table *ct = hw_to_ccu_div_table(hw);
+ unsigned long flags;
+ unsigned int index;
+ u32 reg;
+
+ ccu_div_table_find_best(parent_rate, rate, ct, &index);CCF provides divider_get_val().
quoted hunk ↗ jump to hunk
+ + spin_lock_irqsave(ct->common.lock, flags); + + reg = readl(ct->common.base + ct->common.reg); + reg &= ~GENMASK(ct->div.width + ct->div.shift, ct->div.shift); + writel(reg | ((ct->table[index]) << ct->div.shift), + ct->common.base + ct->common.reg); + + spin_unlock_irqrestore(ct->common.lock, flags); + + return 0; +} + +const struct clk_ops ccu_div_table_ops = { + .disable = ccu_div_table_disable, + .enable = ccu_div_table_enable, + .is_enabled = ccu_div_table_is_enabled, + + .recalc_rate = ccu_div_table_recalc_rate, + .round_rate = ccu_div_table_round_rate, + .set_rate = ccu_div_table_set_rate, +};diff --git a/drivers/clk/sunxi-ng/ccu_div_table.h b/drivers/clk/sunxi-ng/ccu_div_table.h new file mode 100644 index 000000000000..bd7da49087ed --- /dev/null +++ b/drivers/clk/sunxi-ng/ccu_div_table.h@@ -0,0 +1,75 @@ +/* + * 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_DIV_TABLE_H_ +#define _CCU_DIV_TABLE_H_ + +#include <linux/clk-provider.h> + +#include "ccu_common.h" +#include "ccu_factor.h" + +struct ccu_div_table { + u32 enable; + + u8 *table;
I suggest using struct clk_div_table instead, to be able to use the CCF helpers.
+ int num_divs;
This field won't be needed then, but you should add a divider flags field. Regards ChenYu
+
+ struct ccu_factor div;
+ struct ccu_common common;
+};
+
+#define SUNXI_CCU_DIV_TABLE(_struct, _name, _parent, _reg, \
+ _shift, _width, \
+ _table, _flags) \
+ struct ccu_div_table _struct = { \
+ .table = _table, \
+ .num_divs = ARRAY_SIZE(_table), \
+ .div = SUNXI_CLK_FACTOR(_shift, _width), \
+ .common = { \
+ .reg = _reg, \
+ .hw.init = SUNXI_HW_INIT(_name, \
+ _parent, \
+ &ccu_div_table_ops, \
+ _flags), \
+ } \
+ }
+
+#define SUNXI_CCU_DIV_TABLE_WITH_GATE(_struct, _name, _parent, _reg, \
+ _shift, _width, \
+ _table, _gate, _flags) \
+ struct ccu_div_table _struct = { \
+ .enable = _gate, \
+ .table = _table, \
+ .num_divs = ARRAY_SIZE(_table), \
+ .div = SUNXI_CLK_FACTOR(_shift, _width), \
+ .common = { \
+ .reg = _reg, \
+ .features = CCU_FEATURE_GATE, \
+ .hw.init = SUNXI_HW_INIT(_name, \
+ _parent, \
+ &ccu_div_table_ops, \
+ _flags), \
+ } \
+ }
+
+static inline struct ccu_div_table *hw_to_ccu_div_table(struct clk_hw *hw)
+{
+ struct ccu_common *common = hw_to_ccu_common(hw);
+
+ return container_of(common, struct ccu_div_table, common);
+}
+
+extern const struct clk_ops ccu_div_table_ops;
+
+#endif /* _CCU_DIV_H_ */
--
2.8.2