[PATCH 11/16] clk: sunxi-ng: Add N-K-factor clock support
From: Chen-Yu Tsai <hidden>
Date: 2016-05-23 13:58:04
Also in:
linux-clk
Hi, On Mon, May 9, 2016 at 4:01 AM, Maxime Ripard [off-list ref] wrote:
Introduce support for clocks that use a combination of two linear multipliers.
Mostly the same comments as the previous patch.
quoted hunk ↗ jump to hunk
Signed-off-by: Maxime Ripard <redacted> --- drivers/clk/sunxi-ng/Makefile | 1 + drivers/clk/sunxi-ng/ccu_nk.c | 147 ++++++++++++++++++++++++++++++++++++++++++ drivers/clk/sunxi-ng/ccu_nk.h | 44 +++++++++++++ 3 files changed, 192 insertions(+) create mode 100644 drivers/clk/sunxi-ng/ccu_nk.c create mode 100644 drivers/clk/sunxi-ng/ccu_nk.hdiff --git a/drivers/clk/sunxi-ng/Makefile b/drivers/clk/sunxi-ng/Makefile index 09fce7467784..e29ddae99653 100644 --- a/drivers/clk/sunxi-ng/Makefile +++ b/drivers/clk/sunxi-ng/Makefile@@ -7,5 +7,6 @@ obj-y += ccu_gate.o obj-y += ccu_m.o obj-y += ccu_mp.o obj-y += ccu_mux.o +obj-y += ccu_nk.o obj-y += ccu_p.o obj-y += ccu_phase.odiff --git a/drivers/clk/sunxi-ng/ccu_nk.c b/drivers/clk/sunxi-ng/ccu_nk.c new file mode 100644 index 000000000000..46eede3e986e --- /dev/null +++ b/drivers/clk/sunxi-ng/ccu_nk.c@@ -0,0 +1,147 @@ +/* + * 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 <linux/rational.h> + +#include "ccu_gate.h" +#include "ccu_nk.h"
A formula to check against would be nice.
+void ccu_nk_find_best(unsigned long parent, unsigned long rate,
+ unsigned int max_n, unsigned int max_k,
+ unsigned int *n, unsigned int *k)
+{
+ unsigned long best_rate = 0;
+ unsigned int best_k = 0, best_n =0;
+ unsigned int _k, _n;
+
+ for (_k = 0; _k <= max_k; _k++) {
+ for (_n = 0; _n <= max_n; _n++) {I don't think 0 is a valid multiplier, regardless whether the N value in the register starts from 0 or 1.
+ unsigned long tmp_rate = parent * _n * _k;
+
+ if (tmp_rate > rate)
+ continue;
+
+ if ((rate - tmp_rate) < (rate - best_rate)) {
+ best_rate = tmp_rate;
+ best_k = _k;
+ best_n = _n;
+ }
+ }
+ }
+
+ *k = best_k;
+ *n = best_n;
+}
+
+static void ccu_nk_disable(struct clk_hw *hw)
+{
+ struct ccu_nk *nk = hw_to_ccu_nk(hw);
+
+ return ccu_gate_helper_disable(&nk->common, nk->enable);
+}
+
+static int ccu_nk_enable(struct clk_hw *hw)
+{
+ struct ccu_nk *nk = hw_to_ccu_nk(hw);
+
+ return ccu_gate_helper_enable(&nk->common, nk->enable);
+}
+
+static int ccu_nk_is_enabled(struct clk_hw *hw)
+{
+ struct ccu_nk *nk = hw_to_ccu_nk(hw);
+
+ return ccu_gate_helper_is_enabled(&nk->common, nk->enable);
+}
+
+static unsigned long ccu_nk_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct ccu_nk *nk = hw_to_ccu_nk(hw);
+ unsigned long rate, n, k;
+ u32 reg;
+
+ reg = readl(nk->common.base + nk->common.reg);
+
+ n = reg >> nk->n.shift;
+ n &= (1 << nk->n.width) - 1;
+
+ k = reg >> nk->k.shift;
+ k &= (1 << nk->k.width) - 1;
+
+ rate = parent_rate * (n + 1) * (k + 1);
+
+ if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
+ rate = rate / nk->fixed_post_div;I would go with "rate /= nk->fixed_post_div", but it's purely aesthetics.
+
+ return rate;
+}
+
+static long ccu_nk_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ struct ccu_nk *nk = hw_to_ccu_nk(hw);
+ unsigned int n, k;
+
+ if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
+ rate = rate * nk->fixed_post_div;
+
+ ccu_nk_find_best(*parent_rate, rate,
+ 1 << nk->n.width, 1 << nk->k.width,
+ &n, &k);
+
+ rate = *parent_rate * n * k;
+ if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
+ rate = rate / nk->fixed_post_div;
+
+ return rate;
+}
+
+static int ccu_nk_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct ccu_nk *nk = hw_to_ccu_nk(hw);
+ unsigned long flags;
+ unsigned int n, k;
+ u32 reg;
+
+ if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
+ rate = rate * nk->fixed_post_div;
+
+ ccu_nk_find_best(parent_rate, rate,
+ 1 << nk->n.width, 1 << nk->k.width,
+ &n, &k);
+
+ spin_lock_irqsave(nk->common.lock, flags);
+
+ reg = readl(nk->common.base + nk->common.reg);
+ reg &= ~GENMASK(nk->n.width + nk->n.shift, nk->n.shift);
+ reg &= ~GENMASK(nk->k.width + nk->k.shift, nk->k.shift);width + shift - 1
quoted hunk ↗ jump to hunk
+ + writel(reg | ((k - 1) << nk->k.shift) | ((n - 1) << nk->n.shift), + nk->common.base + nk->common.reg); + + spin_unlock_irqrestore(nk->common.lock, flags); + + ccu_helper_wait_for_lock(&nk->common, nk->lock); + + return 0; +} + +const struct clk_ops ccu_nk_ops = { + .disable = ccu_nk_disable, + .enable = ccu_nk_enable, + .is_enabled = ccu_nk_is_enabled, + + .recalc_rate = ccu_nk_recalc_rate, + .round_rate = ccu_nk_round_rate, + .set_rate = ccu_nk_set_rate, +};diff --git a/drivers/clk/sunxi-ng/ccu_nk.h b/drivers/clk/sunxi-ng/ccu_nk.h new file mode 100644 index 000000000000..cdbbd45815c6 --- /dev/null +++ b/drivers/clk/sunxi-ng/ccu_nk.h@@ -0,0 +1,44 @@ +/* + * 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_NK_H_ +#define _CCU_NK_H_ + +#include <linux/clk-provider.h> + +#include "ccu_common.h" +#include "ccu_factor.h" + +struct ccu_nk { + u16 reg; + u32 enable; + u32 lock; + + struct ccu_factor n; + struct ccu_factor k; + + unsigned int fixed_post_div; + + struct ccu_common common; +}; + +static inline struct ccu_nk *hw_to_ccu_nk(struct clk_hw *hw) +{ + struct ccu_common *common = hw_to_ccu_common(hw); + + return container_of(common, struct ccu_nk, common); +} + +extern const struct clk_ops ccu_nk_ops;
No macros for this one? Regards ChenYu
+ +#endif /* _CCU_NK_H_ */ -- 2.8.2