clk: sunxi-ng: Add N-K-M-P factor clock

Introduce support for clocks that use a combination of two linear
multipliers (N and K factors), one linear divider (M) and one power of two
divider (P).

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20160629190535.11855-13-maxime.ripard@free-electrons.com

diff --git a/drivers/clk/sunxi-ng/Kconfig b/drivers/clk/sunxi-ng/Kconfig
index 4c571b8..24fc9e4 100644 (file)
--- a/drivers/clk/sunxi-ng/Kconfig
+++ b/drivers/clk/sunxi-ng/Kconfig
@@ -33,6 +33,11 @@ config SUNXI_CCU_NKM
        select RATIONAL
        select SUNXI_CCU_GATE
 
+config SUNXI_CCU_NKMP
+       bool
+       select RATIONAL
+       select SUNXI_CCU_GATE
+
 config SUNXI_CCU_NM
        bool
        select RATIONAL

diff --git a/drivers/clk/sunxi-ng/Makefile b/drivers/clk/sunxi-ng/Makefile
index 2d6fdca..5c342cc 100644 (file)
--- a/drivers/clk/sunxi-ng/Makefile
+++ b/drivers/clk/sunxi-ng/Makefile
@@ -12,5 +12,6 @@ obj-$(CONFIG_SUNXI_CCU_PHASE) += ccu_phase.o
 # Multi-factor clocks
 obj-$(CONFIG_SUNXI_CCU_NK)     += ccu_nk.o
 obj-$(CONFIG_SUNXI_CCU_NKM)    += ccu_nkm.o
+obj-$(CONFIG_SUNXI_CCU_NKMP)   += ccu_nkmp.o
 obj-$(CONFIG_SUNXI_CCU_NM)     += ccu_nm.o
 obj-$(CONFIG_SUNXI_CCU_MP)     += ccu_mp.o

diff --git a/drivers/clk/sunxi-ng/ccu_nkmp.c b/drivers/clk/sunxi-ng/ccu_nkmp.c
new file mode 100644 (file)
index 0000000..9f2b98e
--- /dev/null
+++ b/drivers/clk/sunxi-ng/ccu_nkmp.c
@@ -0,0 +1,167 @@
+/*
+ * 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_nkmp.h"
+
+struct _ccu_nkmp {
+       unsigned long   n, max_n;
+       unsigned long   k, max_k;
+       unsigned long   m, max_m;
+       unsigned long   p, max_p;
+};
+
+static void ccu_nkmp_find_best(unsigned long parent, unsigned long rate,
+                              struct _ccu_nkmp *nkmp)
+{
+       unsigned long best_rate = 0;
+       unsigned long best_n = 0, best_k = 0, best_m = 0, best_p = 0;
+       unsigned long _n, _k, _m, _p;
+
+       for (_k = 1; _k <= nkmp->max_k; _k++) {
+               for (_p = 0; _p <= nkmp->max_p; _p++) {
+                       unsigned long tmp_rate;
+
+                       rational_best_approximation(rate / _k, parent >> _p,
+                                                   nkmp->max_n, nkmp->max_m,
+                                                   &_n, &_m);
+
+                       tmp_rate = (parent * _n * _k >> _p) / _m;
+
+                       if (tmp_rate > rate)
+                               continue;
+
+                       if ((rate - tmp_rate) < (rate - best_rate)) {
+                               best_rate = tmp_rate;
+                               best_n = _n;
+                               best_k = _k;
+                               best_m = _m;
+                               best_p = _p;
+                       }
+               }
+       }
+
+       nkmp->n = best_n;
+       nkmp->k = best_k;
+       nkmp->m = best_m;
+       nkmp->p = best_p;
+}
+
+static void ccu_nkmp_disable(struct clk_hw *hw)
+{
+       struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);
+
+       return ccu_gate_helper_disable(&nkmp->common, nkmp->enable);
+}
+
+static int ccu_nkmp_enable(struct clk_hw *hw)
+{
+       struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);
+
+       return ccu_gate_helper_enable(&nkmp->common, nkmp->enable);
+}
+
+static int ccu_nkmp_is_enabled(struct clk_hw *hw)
+{
+       struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);
+
+       return ccu_gate_helper_is_enabled(&nkmp->common, nkmp->enable);
+}
+
+static unsigned long ccu_nkmp_recalc_rate(struct clk_hw *hw,
+                                       unsigned long parent_rate)
+{
+       struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);
+       unsigned long n, m, k, p;
+       u32 reg;
+
+       reg = readl(nkmp->common.base + nkmp->common.reg);
+
+       n = reg >> nkmp->n.shift;
+       n &= (1 << nkmp->n.width) - 1;
+
+       k = reg >> nkmp->k.shift;
+       k &= (1 << nkmp->k.width) - 1;
+
+       m = reg >> nkmp->m.shift;
+       m &= (1 << nkmp->m.width) - 1;
+
+       p = reg >> nkmp->p.shift;
+       p &= (1 << nkmp->p.width) - 1;
+
+       return (parent_rate * (n + 1) * (k + 1) >> p) / (m + 1);
+}
+
+static long ccu_nkmp_round_rate(struct clk_hw *hw, unsigned long rate,
+                             unsigned long *parent_rate)
+{
+       struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);
+       struct _ccu_nkmp _nkmp;
+
+       _nkmp.max_n = 1 << nkmp->n.width;
+       _nkmp.max_k = 1 << nkmp->k.width;
+       _nkmp.max_m = 1 << nkmp->m.width;
+       _nkmp.max_p = (1 << nkmp->p.width) - 1;
+
+       ccu_nkmp_find_best(*parent_rate, rate,
+                          &_nkmp);
+
+       return (*parent_rate * _nkmp.n * _nkmp.k >> _nkmp.p) / _nkmp.m;
+}
+
+static int ccu_nkmp_set_rate(struct clk_hw *hw, unsigned long rate,
+                          unsigned long parent_rate)
+{
+       struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);
+       struct _ccu_nkmp _nkmp;
+       unsigned long flags;
+       u32 reg;
+
+       _nkmp.max_n = 1 << nkmp->n.width;
+       _nkmp.max_k = 1 << nkmp->k.width;
+       _nkmp.max_m = 1 << nkmp->m.width;
+       _nkmp.max_p = (1 << nkmp->p.width) - 1;
+
+       ccu_nkmp_find_best(parent_rate, rate, &_nkmp);
+
+       spin_lock_irqsave(nkmp->common.lock, flags);
+
+       reg = readl(nkmp->common.base + nkmp->common.reg);
+       reg &= ~GENMASK(nkmp->n.width + nkmp->n.shift - 1, nkmp->n.shift);
+       reg &= ~GENMASK(nkmp->k.width + nkmp->k.shift - 1, nkmp->k.shift);
+       reg &= ~GENMASK(nkmp->m.width + nkmp->m.shift - 1, nkmp->m.shift);
+       reg &= ~GENMASK(nkmp->p.width + nkmp->p.shift - 1, nkmp->p.shift);
+
+       reg |= (_nkmp.n - 1) << nkmp->n.shift;
+       reg |= (_nkmp.k - 1) << nkmp->k.shift;
+       reg |= (_nkmp.m - 1) << nkmp->m.shift;
+       reg |= _nkmp.p << nkmp->p.shift;
+
+       writel(reg, nkmp->common.base + nkmp->common.reg);
+
+       spin_unlock_irqrestore(nkmp->common.lock, flags);
+
+       ccu_helper_wait_for_lock(&nkmp->common, nkmp->lock);
+
+       return 0;
+}
+
+const struct clk_ops ccu_nkmp_ops = {
+       .disable        = ccu_nkmp_disable,
+       .enable         = ccu_nkmp_enable,
+       .is_enabled     = ccu_nkmp_is_enabled,
+
+       .recalc_rate    = ccu_nkmp_recalc_rate,
+       .round_rate     = ccu_nkmp_round_rate,
+       .set_rate       = ccu_nkmp_set_rate,
+};

diff --git a/drivers/clk/sunxi-ng/ccu_nkmp.h b/drivers/clk/sunxi-ng/ccu_nkmp.h
new file mode 100644 (file)
index 0000000..5adb0c9
--- /dev/null
+++ b/drivers/clk/sunxi-ng/ccu_nkmp.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_NKMP_H_
+#define _CCU_NKMP_H_
+
+#include <linux/clk-provider.h>
+
+#include "ccu_common.h"
+#include "ccu_div.h"
+#include "ccu_mult.h"
+
+/*
+ * struct ccu_nkmp - Definition of an N-K-M-P clock
+ *
+ * Clocks based on the formula parent * N * K >> P / M
+ */
+struct ccu_nkmp {
+       u32                     enable;
+       u32                     lock;
+
+       struct _ccu_mult        n;
+       struct _ccu_mult        k;
+       struct _ccu_div         m;
+       struct _ccu_div         p;
+
+       struct ccu_common       common;
+};
+
+#define SUNXI_CCU_NKMP_WITH_GATE_LOCK(_struct, _name, _parent, _reg,   \
+                                     _nshift, _nwidth,                 \
+                                     _kshift, _kwidth,                 \
+                                     _mshift, _mwidth,                 \
+                                     _pshift, _pwidth,                 \
+                                     _gate, _lock, _flags)             \
+       struct ccu_nkmp _struct = {                                     \
+               .enable         = _gate,                                \
+               .lock           = _lock,                                \
+               .n              = _SUNXI_CCU_MULT(_nshift, _nwidth),    \
+               .k              = _SUNXI_CCU_MULT(_kshift, _kwidth),    \
+               .m              = _SUNXI_CCU_DIV(_mshift, _mwidth),     \
+               .p              = _SUNXI_CCU_DIV(_pshift, _pwidth),     \
+               .common         = {                                     \
+                       .reg            = _reg,                         \
+                       .hw.init        = CLK_HW_INIT(_name,            \
+                                                     _parent,          \
+                                                     &ccu_nkmp_ops,    \
+                                                     _flags),          \
+               },                                                      \
+       }
+
+static inline struct ccu_nkmp *hw_to_ccu_nkmp(struct clk_hw *hw)
+{
+       struct ccu_common *common = hw_to_ccu_common(hw);
+
+       return container_of(common, struct ccu_nkmp, common);
+}
+
+extern const struct clk_ops ccu_nkmp_ops;
+
+#endif /* _CCU_NKMP_H_ */