clk: sunxi-ng: Add N-K-M Factor clock

Introduce support for clocks that multiply and divide using two linear
multipliers and one linear divider.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20160629190535.11855-12-maxime.ripard@free-electrons.com

diff --git a/drivers/clk/sunxi-ng/Kconfig b/drivers/clk/sunxi-ng/Kconfig
index d8a5da270778eb1e7d5288167d8b6e6395e40832..4c571b86bfd1c2ba1b8fc9fe7bb8e0df4c230544 100644 (file)
--- a/drivers/clk/sunxi-ng/Kconfig
+++ b/drivers/clk/sunxi-ng/Kconfig
@@ -28,6 +28,11 @@ config SUNXI_CCU_NK
        bool
        select SUNXI_CCU_GATE
 
+config SUNXI_CCU_NKM
+       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 7d2cd2a47a3938752f2798ff1008c6aad8dfa63b..2d6fdca0d3cc2e7c6d7d623a6dd8823443a27649 100644 (file)
--- a/drivers/clk/sunxi-ng/Makefile
+++ b/drivers/clk/sunxi-ng/Makefile
@@ -11,5 +11,6 @@ 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-$(CONFIG_SUNXI_CCU_NM)     += ccu_nm.o
 obj-$(CONFIG_SUNXI_CCU_MP)     += ccu_mp.o

diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c
new file mode 100644 (file)
index 0000000..2071822
--- /dev/null
+++ b/drivers/clk/sunxi-ng/ccu_nkm.c
@@ -0,0 +1,153 @@
+/*
+ * 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_nkm.h"
+
+struct _ccu_nkm {
+       unsigned long   n, max_n;
+       unsigned long   k, max_k;
+       unsigned long   m, max_m;
+};
+
+static void ccu_nkm_find_best(unsigned long parent, unsigned long rate,
+                             struct _ccu_nkm *nkm)
+{
+       unsigned long best_rate = 0;
+       unsigned long best_n = 0, best_k = 0, best_m = 0;
+       unsigned long _n, _k, _m;
+
+       for (_k = 1; _k <= nkm->max_k; _k++) {
+               unsigned long tmp_rate;
+
+               rational_best_approximation(rate / _k, parent,
+                                           nkm->max_n, nkm->max_m, &_n, &_m);
+
+               tmp_rate = parent * _n * _k / _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;
+               }
+       }
+
+       nkm->n = best_n;
+       nkm->k = best_k;
+       nkm->m = best_m;
+}
+
+static void ccu_nkm_disable(struct clk_hw *hw)
+{
+       struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
+
+       return ccu_gate_helper_disable(&nkm->common, nkm->enable);
+}
+
+static int ccu_nkm_enable(struct clk_hw *hw)
+{
+       struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
+
+       return ccu_gate_helper_enable(&nkm->common, nkm->enable);
+}
+
+static int ccu_nkm_is_enabled(struct clk_hw *hw)
+{
+       struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
+
+       return ccu_gate_helper_is_enabled(&nkm->common, nkm->enable);
+}
+
+static unsigned long ccu_nkm_recalc_rate(struct clk_hw *hw,
+                                       unsigned long parent_rate)
+{
+       struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
+       unsigned long n, m, k;
+       u32 reg;
+
+       reg = readl(nkm->common.base + nkm->common.reg);
+
+       n = reg >> nkm->n.shift;
+       n &= (1 << nkm->n.width) - 1;
+
+       k = reg >> nkm->k.shift;
+       k &= (1 << nkm->k.width) - 1;
+
+       m = reg >> nkm->m.shift;
+       m &= (1 << nkm->m.width) - 1;
+
+       return parent_rate * (n + 1) * (k + 1) / (m + 1);
+}
+
+static long ccu_nkm_round_rate(struct clk_hw *hw, unsigned long rate,
+                             unsigned long *parent_rate)
+{
+       struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
+       struct _ccu_nkm _nkm;
+
+       _nkm.max_n = 1 << nkm->n.width;
+       _nkm.max_k = 1 << nkm->k.width;
+       _nkm.max_m = 1 << nkm->m.width;
+
+       ccu_nkm_find_best(*parent_rate, rate, &_nkm);
+
+       return *parent_rate * _nkm.n * _nkm.k / _nkm.m;
+}
+
+static int ccu_nkm_set_rate(struct clk_hw *hw, unsigned long rate,
+                          unsigned long parent_rate)
+{
+       struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
+       struct _ccu_nkm _nkm;
+       unsigned long flags;
+       u32 reg;
+
+       _nkm.max_n = 1 << nkm->n.width;
+       _nkm.max_k = 1 << nkm->k.width;
+       _nkm.max_m = 1 << nkm->m.width;
+
+       ccu_nkm_find_best(parent_rate, rate, &_nkm);
+
+       spin_lock_irqsave(nkm->common.lock, flags);
+
+       reg = readl(nkm->common.base + nkm->common.reg);
+       reg &= ~GENMASK(nkm->n.width + nkm->n.shift - 1, nkm->n.shift);
+       reg &= ~GENMASK(nkm->k.width + nkm->k.shift - 1, nkm->k.shift);
+       reg &= ~GENMASK(nkm->m.width + nkm->m.shift - 1, nkm->m.shift);
+
+       reg |= (_nkm.n - 1) << nkm->n.shift;
+       reg |= (_nkm.k - 1) << nkm->k.shift;
+       reg |= (_nkm.m - 1) << nkm->m.shift;
+
+       writel(reg, nkm->common.base + nkm->common.reg);
+
+       spin_unlock_irqrestore(nkm->common.lock, flags);
+
+       ccu_helper_wait_for_lock(&nkm->common, nkm->lock);
+
+       return 0;
+}
+
+const struct clk_ops ccu_nkm_ops = {
+       .disable        = ccu_nkm_disable,
+       .enable         = ccu_nkm_enable,
+       .is_enabled     = ccu_nkm_is_enabled,
+
+       .recalc_rate    = ccu_nkm_recalc_rate,
+       .round_rate     = ccu_nkm_round_rate,
+       .set_rate       = ccu_nkm_set_rate,
+};

diff --git a/drivers/clk/sunxi-ng/ccu_nkm.h b/drivers/clk/sunxi-ng/ccu_nkm.h
new file mode 100644 (file)
index 0000000..1936ac1
--- /dev/null
+++ b/drivers/clk/sunxi-ng/ccu_nkm.h
@@ -0,0 +1,68 @@
+/*
+ * 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_NKM_H_
+#define _CCU_NKM_H_
+
+#include <linux/clk-provider.h>
+
+#include "ccu_common.h"
+#include "ccu_div.h"
+#include "ccu_mult.h"
+
+/*
+ * struct ccu_nkm - Definition of an N-K-M clock
+ *
+ * Clocks based on the formula parent * N * K / M
+ */
+struct ccu_nkm {
+       u32                     enable;
+       u32                     lock;
+
+       struct _ccu_mult        n;
+       struct _ccu_mult        k;
+       struct _ccu_div         m;
+
+       struct ccu_common       common;
+};
+
+#define SUNXI_CCU_NKM_WITH_GATE_LOCK(_struct, _name, _parent, _reg,    \
+                                    _nshift, _nwidth,                  \
+                                    _kshift, _kwidth,                  \
+                                    _mshift, _mwidth,                  \
+                                    _gate, _lock, _flags)              \
+       struct ccu_nkm _struct = {                                      \
+               .enable         = _gate,                                \
+               .lock           = _lock,                                \
+               .k              = _SUNXI_CCU_MULT(_kshift, _kwidth),    \
+               .n              = _SUNXI_CCU_MULT(_nshift, _nwidth),    \
+               .m              = _SUNXI_CCU_DIV(_mshift, _mwidth),     \
+               .common         = {                                     \
+                       .reg            = _reg,                         \
+                       .hw.init        = CLK_HW_INIT(_name,            \
+                                                     _parent,          \
+                                                     &ccu_nkm_ops,     \
+                                                     _flags),          \
+               },                                                      \
+       }
+
+static inline struct ccu_nkm *hw_to_ccu_nkm(struct clk_hw *hw)
+{
+       struct ccu_common *common = hw_to_ccu_common(hw);
+
+       return container_of(common, struct ccu_nkm, common);
+}
+
+extern const struct clk_ops ccu_nkm_ops;
+
+#endif /* _CCU_NKM_H_ */