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authorMaxime Ripard <maxime.ripard@free-electrons.com>2016-06-29 21:05:30 +0200
committerMichael Turquette <mturquette@baylibre.com>2016-07-08 18:04:56 -0700
commitadbfb0056e03d556b98ffe93da0d7126bd630096 (patch)
treea69864c7f6532408c6c4991cf06eb4988936fa01
parent2ab836db5097427c3bfa58f9bd7230513c2f3665 (diff)
clk: sunxi-ng: Add N-K-factor clock support
Introduce support for clocks that use a combination of two linear multipliers. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Michael Turquette <mturquette@baylibre.com> Link: lkml.kernel.org/r/20160629190535.11855-10-maxime.ripard@free-electrons.com
-rw-r--r--drivers/clk/sunxi-ng/Kconfig4
-rw-r--r--drivers/clk/sunxi-ng/Makefile1
-rw-r--r--drivers/clk/sunxi-ng/ccu_nk.c147
-rw-r--r--drivers/clk/sunxi-ng/ccu_nk.h71
4 files changed, 223 insertions, 0 deletions
diff --git a/drivers/clk/sunxi-ng/Kconfig b/drivers/clk/sunxi-ng/Kconfig
index fc970b5..2eb0fc6 100644
--- a/drivers/clk/sunxi-ng/Kconfig
+++ b/drivers/clk/sunxi-ng/Kconfig
@@ -24,6 +24,10 @@ config SUNXI_CCU_PHASE
# Multi-factor clocks
+config SUNXI_CCU_NK
+ bool
+ select SUNXI_CCU_GATE
+
config SUNXI_CCU_MP
bool
select SUNXI_CCU_GATE
diff --git a/drivers/clk/sunxi-ng/Makefile b/drivers/clk/sunxi-ng/Makefile
index 501dec9..22951e6 100644
--- a/drivers/clk/sunxi-ng/Makefile
+++ b/drivers/clk/sunxi-ng/Makefile
@@ -10,4 +10,5 @@ obj-$(CONFIG_SUNXI_CCU_MUX) += ccu_mux.o
obj-$(CONFIG_SUNXI_CCU_PHASE) += ccu_phase.o
# Multi-factor clocks
+obj-$(CONFIG_SUNXI_CCU_NK) += ccu_nk.o
obj-$(CONFIG_SUNXI_CCU_MP) += ccu_mp.o
diff --git a/drivers/clk/sunxi-ng/ccu_nk.c b/drivers/clk/sunxi-ng/ccu_nk.c
new file mode 100644
index 0000000..4470ffc
--- /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"
+
+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 = 1; _k <= max_k; _k++) {
+ for (_n = 1; _n <= max_n; _n++) {
+ 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 /= nk->fixed_post_div;
+
+ 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 *= 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 - 1, nk->n.shift);
+ reg &= ~GENMASK(nk->k.width + nk->k.shift - 1, nk->k.shift);
+
+ 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 0000000..4b52da0
--- /dev/null
+++ b/drivers/clk/sunxi-ng/ccu_nk.h
@@ -0,0 +1,71 @@
+/*
+ * 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_div.h"
+#include "ccu_mult.h"
+
+/*
+ * struct ccu_nk - Definition of an N-K clock
+ *
+ * Clocks based on the formula parent * N * K
+ */
+struct ccu_nk {
+ u16 reg;
+ u32 enable;
+ u32 lock;
+
+ struct _ccu_mult n;
+ struct _ccu_mult k;
+
+ unsigned int fixed_post_div;
+
+ struct ccu_common common;
+};
+
+#define SUNXI_CCU_NK_WITH_GATE_LOCK_POSTDIV(_struct, _name, _parent, _reg, \
+ _nshift, _nwidth, \
+ _kshift, _kwidth, \
+ _gate, _lock, _postdiv, \
+ _flags) \
+ struct ccu_nk _struct = { \
+ .enable = _gate, \
+ .lock = _lock, \
+ .k = _SUNXI_CCU_MULT(_kshift, _kwidth), \
+ .n = _SUNXI_CCU_MULT(_nshift, _nwidth), \
+ .fixed_post_div = _postdiv, \
+ .common = { \
+ .reg = _reg, \
+ .features = CCU_FEATURE_FIXED_POSTDIV, \
+ .hw.init = CLK_HW_INIT(_name, \
+ _parent, \
+ &ccu_nk_ops, \
+ _flags), \
+ }, \
+ }
+
+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;
+
+#endif /* _CCU_NK_H_ */