clk: sunxi-ng: Add M-P factor clock support

Introduce support for the clocks that combine a linear divider and a
power-of-two based one.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20160629190535.11855-9-maxime.ripard@free-electrons.com

diff --git a/drivers/clk/sunxi-ng/Kconfig b/drivers/clk/sunxi-ng/Kconfig
index 7e65e77..fc970b5 100644 (file)
--- a/drivers/clk/sunxi-ng/Kconfig
+++ b/drivers/clk/sunxi-ng/Kconfig
@@ -22,4 +22,11 @@ config SUNXI_CCU_MUX
 config SUNXI_CCU_PHASE
        bool
 
+# Multi-factor clocks
+
+config SUNXI_CCU_MP
+       bool
+       select SUNXI_CCU_GATE
+       select SUNXI_CCU_MUX
+
 endif

diff --git a/drivers/clk/sunxi-ng/Makefile b/drivers/clk/sunxi-ng/Makefile
index 4bc5b61..501dec9 100644 (file)
--- a/drivers/clk/sunxi-ng/Makefile
+++ b/drivers/clk/sunxi-ng/Makefile
@@ -8,3 +8,6 @@ obj-$(CONFIG_SUNXI_CCU_FRAC)    += ccu_frac.o
 obj-$(CONFIG_SUNXI_CCU_GATE)   += ccu_gate.o
 obj-$(CONFIG_SUNXI_CCU_MUX)    += ccu_mux.o
 obj-$(CONFIG_SUNXI_CCU_PHASE)  += ccu_phase.o
+
+# Multi-factor clocks
+obj-$(CONFIG_SUNXI_CCU_MP)     += ccu_mp.o

diff --git a/drivers/clk/sunxi-ng/ccu_mp.c b/drivers/clk/sunxi-ng/ccu_mp.c
new file mode 100644 (file)
index 0000000..cbf33ef
--- /dev/null
+++ b/drivers/clk/sunxi-ng/ccu_mp.c
@@ -0,0 +1,158 @@
+/*
+ * 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_gate.h"
+#include "ccu_mp.h"
+
+static void ccu_mp_find_best(unsigned long parent, unsigned long rate,
+                            unsigned int max_m, unsigned int max_p,
+                            unsigned int *m, unsigned int *p)
+{
+       unsigned long best_rate = 0;
+       unsigned int best_m = 0, best_p = 0;
+       unsigned int _m, _p;
+
+       for (_p = 0; _p <= max_p; _p++) {
+               for (_m = 1; _m <= max_m; _m++) {
+                       unsigned long tmp_rate = (parent >> _p) / _m;
+
+                       if (tmp_rate > rate)
+                               continue;
+
+                       if ((rate - tmp_rate) < (rate - best_rate)) {
+                               best_rate = tmp_rate;
+                               best_m = _m;
+                               best_p = _p;
+                       }
+               }
+       }
+
+       *m = best_m;
+       *p = best_p;
+}
+
+static unsigned long ccu_mp_round_rate(struct ccu_mux_internal *mux,
+                                      unsigned long parent_rate,
+                                      unsigned long rate,
+                                      void *data)
+{
+       struct ccu_mp *cmp = data;
+       unsigned int m, p;
+
+       ccu_mp_find_best(parent_rate, rate,
+                        1 << cmp->m.width, (1 << cmp->p.width) - 1,
+                        &m, &p);
+
+       return (parent_rate >> p) / m;
+}
+
+static void ccu_mp_disable(struct clk_hw *hw)
+{
+       struct ccu_mp *cmp = hw_to_ccu_mp(hw);
+
+       return ccu_gate_helper_disable(&cmp->common, cmp->enable);
+}
+
+static int ccu_mp_enable(struct clk_hw *hw)
+{
+       struct ccu_mp *cmp = hw_to_ccu_mp(hw);
+
+       return ccu_gate_helper_enable(&cmp->common, cmp->enable);
+}
+
+static int ccu_mp_is_enabled(struct clk_hw *hw)
+{
+       struct ccu_mp *cmp = hw_to_ccu_mp(hw);
+
+       return ccu_gate_helper_is_enabled(&cmp->common, cmp->enable);
+}
+
+static unsigned long ccu_mp_recalc_rate(struct clk_hw *hw,
+                                       unsigned long parent_rate)
+{
+       struct ccu_mp *cmp = hw_to_ccu_mp(hw);
+       unsigned int m, p;
+       u32 reg;
+
+       reg = readl(cmp->common.base + cmp->common.reg);
+
+       m = reg >> cmp->m.shift;
+       m &= (1 << cmp->m.width) - 1;
+
+       p = reg >> cmp->p.shift;
+       p &= (1 << cmp->p.width) - 1;
+
+       return (parent_rate >> p) / (m + 1);
+}
+
+static int ccu_mp_determine_rate(struct clk_hw *hw,
+                                struct clk_rate_request *req)
+{
+       struct ccu_mp *cmp = hw_to_ccu_mp(hw);
+
+       return ccu_mux_helper_determine_rate(&cmp->common, &cmp->mux,
+                                            req, ccu_mp_round_rate, cmp);
+}
+
+static int ccu_mp_set_rate(struct clk_hw *hw, unsigned long rate,
+                          unsigned long parent_rate)
+{
+       struct ccu_mp *cmp = hw_to_ccu_mp(hw);
+       unsigned long flags;
+       unsigned int m, p;
+       u32 reg;
+
+       ccu_mp_find_best(parent_rate, rate,
+                        1 << cmp->m.width, (1 << cmp->p.width) - 1,
+                        &m, &p);
+
+
+       spin_lock_irqsave(cmp->common.lock, flags);
+
+       reg = readl(cmp->common.base + cmp->common.reg);
+       reg &= ~GENMASK(cmp->m.width + cmp->m.shift - 1, cmp->m.shift);
+       reg &= ~GENMASK(cmp->p.width + cmp->p.shift - 1, cmp->p.shift);
+
+       writel(reg | (p << cmp->p.shift) | ((m - 1) << cmp->m.shift),
+              cmp->common.base + cmp->common.reg);
+
+       spin_unlock_irqrestore(cmp->common.lock, flags);
+
+       return 0;
+}
+
+static u8 ccu_mp_get_parent(struct clk_hw *hw)
+{
+       struct ccu_mp *cmp = hw_to_ccu_mp(hw);
+
+       return ccu_mux_helper_get_parent(&cmp->common, &cmp->mux);
+}
+
+static int ccu_mp_set_parent(struct clk_hw *hw, u8 index)
+{
+       struct ccu_mp *cmp = hw_to_ccu_mp(hw);
+
+       return ccu_mux_helper_set_parent(&cmp->common, &cmp->mux, index);
+}
+
+const struct clk_ops ccu_mp_ops = {
+       .disable        = ccu_mp_disable,
+       .enable         = ccu_mp_enable,
+       .is_enabled     = ccu_mp_is_enabled,
+
+       .get_parent     = ccu_mp_get_parent,
+       .set_parent     = ccu_mp_set_parent,
+
+       .determine_rate = ccu_mp_determine_rate,
+       .recalc_rate    = ccu_mp_recalc_rate,
+       .set_rate       = ccu_mp_set_rate,
+};

diff --git a/drivers/clk/sunxi-ng/ccu_mp.h b/drivers/clk/sunxi-ng/ccu_mp.h
new file mode 100644 (file)
index 0000000..3cf12bf
--- /dev/null
+++ b/drivers/clk/sunxi-ng/ccu_mp.h
@@ -0,0 +1,77 @@
+/*
+ * 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_MP_H_
+#define _CCU_MP_H_
+
+#include <linux/clk-provider.h>
+
+#include "ccu_common.h"
+#include "ccu_div.h"
+#include "ccu_mult.h"
+#include "ccu_mux.h"
+
+/*
+ * struct ccu_mp - Definition of an M-P clock
+ *
+ * Clocks based on the formula parent >> P / M
+ */
+struct ccu_mp {
+       u32                     enable;
+
+       struct _ccu_div         m;
+       struct _ccu_div         p;
+       struct ccu_mux_internal mux;
+       struct ccu_common       common;
+};
+
+#define SUNXI_CCU_MP_WITH_MUX_GATE(_struct, _name, _parents, _reg,     \
+                                  _mshift, _mwidth,                    \
+                                  _pshift, _pwidth,                    \
+                                  _muxshift, _muxwidth,                \
+                                  _gate, _flags)                       \
+       struct ccu_mp _struct = {                                       \
+               .enable = _gate,                                        \
+               .m      = _SUNXI_CCU_DIV(_mshift, _mwidth),             \
+               .p      = _SUNXI_CCU_DIV(_pshift, _pwidth),             \
+               .mux    = SUNXI_CLK_MUX(_muxshift, _muxwidth),          \
+               .common = {                                             \
+                       .reg            = _reg,                         \
+                       .hw.init        = CLK_HW_INIT_PARENTS(_name,    \
+                                                             _parents, \
+                                                             &ccu_mp_ops, \
+                                                             _flags),  \
+               }                                                       \
+       }
+
+#define SUNXI_CCU_MP_WITH_MUX(_struct, _name, _parents, _reg,          \
+                             _mshift, _mwidth,                         \
+                             _pshift, _pwidth,                         \
+                             _muxshift, _muxwidth,                     \
+                             _flags)                                   \
+       SUNXI_CCU_MP_WITH_MUX_GATE(_struct, _name, _parents, _reg,      \
+                                  _mshift, _mwidth,                    \
+                                  _pshift, _pwidth,                    \
+                                  _muxshift, _muxwidth,                \
+                                  0, _flags)
+
+static inline struct ccu_mp *hw_to_ccu_mp(struct clk_hw *hw)
+{
+       struct ccu_common *common = hw_to_ccu_common(hw);
+
+       return container_of(common, struct ccu_mp, common);
+}
+
+extern const struct clk_ops ccu_mp_ops;
+
+#endif /* _CCU_MP_H_ */