[PATCH v2 11/15] clk: sunxi-ng: Add N-M-factor clock support

Maxime Ripard
2016-06-07T20:41:50Z

Introduce support for clocks that multiply and divide using linear factors.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

---
Changes from v1:
- Fixed the maximums for both factors passed to the rational factor
computation.
---
drivers/clk/sunxi-ng/Makefile | 1 +
drivers/clk/sunxi-ng/ccu_nm.c | 114 ++++++++++++++++++++++++++++++++++++++++++
drivers/clk/sunxi-ng/ccu_nm.h | 95 +++++++++++++++++++++++++++++++++++
3 files changed, 210 insertions(+)
create mode 100644 drivers/clk/sunxi-ng/ccu_nm.c
create mode 100644 drivers/clk/sunxi-ng/ccu_nm.h

diff --git a/drivers/clk/sunxi-ng/Makefile b/drivers/clk/sunxi-ng/Makefile
index a201fad6b11d..5c7ae1ad1082 100644
--- a/drivers/clk/sunxi-ng/Makefile
+++ b/drivers/clk/sunxi-ng/Makefile
@@ -9,4 +9,5 @@ obj-y += ccu_gate.o
obj-y += ccu_mp.o
obj-y += ccu_mux.o
obj-y += ccu_nk.o
+obj-y += ccu_nm.o
obj-y += ccu_phase.o
diff --git a/drivers/clk/sunxi-ng/ccu_nm.c b/drivers/clk/sunxi-ng/ccu_nm.c
new file mode 100644
index 000000000000..e35ddd8eec8b
--- /dev/null
+++ b/drivers/clk/sunxi-ng/ccu_nm.c
@@ -0,0 +1,114 @@
+/*
+ * 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_frac.h"
+#include "ccu_gate.h"
+#include "ccu_nm.h"
+
+static void ccu_nm_disable(struct clk_hw *hw)
+{
+ struct ccu_nm *nm = hw_to_ccu_nm(hw);
+
+ return ccu_gate_helper_disable(&nm->common, nm->enable);
+}
+
+static int ccu_nm_enable(struct clk_hw *hw)
+{
+ struct ccu_nm *nm = hw_to_ccu_nm(hw);
+
+ return ccu_gate_helper_enable(&nm->common, nm->enable);
+}
+
+static int ccu_nm_is_enabled(struct clk_hw *hw)
+{
+ struct ccu_nm *nm = hw_to_ccu_nm(hw);
+
+ return ccu_gate_helper_is_enabled(&nm->common, nm->enable);
+}
+
+static unsigned long ccu_nm_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct ccu_nm *nm = hw_to_ccu_nm(hw);
+ unsigned long n, m;
+ u32 reg;
+
+ if (ccu_frac_helper_is_enabled(&nm->common, &nm->frac))
+ return ccu_frac_helper_read_rate(&nm->common, &nm->frac);
+
+ reg = readl(nm->common.base + nm->common.reg);
+
+ n = reg >> nm->n.shift;
+ n &= (1 << nm->n.width) - 1;
+
+ m = reg >> nm->m.shift;
+ m &= (1 << nm->m.width) - 1;
+
+ return parent_rate * (n + 1) / (m + 1);
+}
+
+static long ccu_nm_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ struct ccu_nm *nm = hw_to_ccu_nm(hw);
+ unsigned long n, m;
+
+ rational_best_approximation(rate, *parent_rate,
+ 1 << nm->n.width, 1 << nm->m.width,
+ &n, &m);
+
+ return *parent_rate * n / m;
+}
+
+static int ccu_nm_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct ccu_nm *nm = hw_to_ccu_nm(hw);
+ unsigned long flags;
+ unsigned long n, m;
+ u32 reg;
+
+ if (ccu_frac_helper_has_rate(&nm->common, &nm->frac, rate))
+ return ccu_frac_helper_set_rate(&nm->common, &nm->frac, rate);
+ else
+ ccu_frac_helper_disable(&nm->common, &nm->frac);
+
+ rational_best_approximation(rate, parent_rate,
+ 1 << nm->n.width, 1 << nm->m.width,
+ &n, &m);
+
+ spin_lock_irqsave(nm->common.lock, flags);
+
+ reg = readl(nm->common.base + nm->common.reg);
+ reg &= ~GENMASK(nm->n.width + nm->n.shift - 1, nm->n.shift);
+ reg &= ~GENMASK(nm->m.width + nm->m.shift - 1, nm->m.shift);
+
+ writel(reg | ((m - 1) << nm->m.shift) | ((n - 1) << nm->n.shift),
+ nm->common.base + nm->common.reg);
+
+ spin_unlock_irqrestore(nm->common.lock, flags);
+
+ ccu_helper_wait_for_lock(&nm->common, nm->lock);
+
+ return 0;
+}
+
+const struct clk_ops ccu_nm_ops = {
+ .disable = ccu_nm_disable,
+ .enable = ccu_nm_enable,
+ .is_enabled = ccu_nm_is_enabled,
+
+ .recalc_rate = ccu_nm_recalc_rate,
+ .round_rate = ccu_nm_round_rate,
+ .set_rate = ccu_nm_set_rate,
+};
diff --git a/drivers/clk/sunxi-ng/ccu_nm.h b/drivers/clk/sunxi-ng/ccu_nm.h
new file mode 100644
index 000000000000..ceabb2e161e5
--- /dev/null
+++ b/drivers/clk/sunxi-ng/ccu_nm.h
@@ -0,0 +1,95 @@
+/*
+ * 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_NM_H_
+#define _CCU_NM_H_
+
+#include <linux/clk-provider.h>
+
+#include "ccu_common.h"
+#include "ccu_div.h"
+#include "ccu_frac.h"
+#include "ccu_mult.h"
+
+/*
+ * struct ccu_nm - Definition of an N-M clock
+ *
+ * Clocks based on the formula parent * N / M
+ */
+struct ccu_nm {
+ u32 enable;
+ u32 lock;
+
+ struct _ccu_mult n;
+ struct _ccu_div m;
+ struct _ccu_frac frac;
+
+ struct ccu_common common;
+};
+
+#define SUNXI_CCU_NM_WITH_FRAC_GATE_LOCK(_struct, _name, _parent, _reg, \
+ _nshift, _nwidth, \
+ _mshift, _mwidth, \
+ _frac_en, _frac_sel, \
+ _frac_rate_0, _frac_rate_1, \
+ _gate, _lock, _flags) \
+ struct ccu_nm _struct = { \
+ .enable = _gate, \
+ .lock = _lock, \
+ .n = _SUNXI_CCU_MULT(_nshift, _nwidth), \
+ .m = _SUNXI_CCU_DIV(_mshift, _mwidth), \
+ .frac = _SUNXI_CCU_FRAC(_frac_en, _frac_sel, \
+ _frac_rate_0, \
+ _frac_rate_1), \
+ .common = { \
+ .reg = _reg, \
+ .features = (CCU_FEATURE_GATE | \
+ CCU_FEATURE_PLL_LOCK | \
+ CCU_FEATURE_FRACTIONAL), \
+ .hw.init = SUNXI_HW_INIT(_name, \
+ _parent, \
+ &ccu_nm_ops, \
+ _flags), \
+ }, \
+ }
+
+#define SUNXI_CCU_NM_WITH_GATE_LOCK(_struct, _name, _parent, _reg, \
+ _nshift, _nwidth, \
+ _mshift, _mwidth, \
+ _gate, _lock, _flags) \
+ struct ccu_nm _struct = { \
+ .enable = _gate, \
+ .lock = _lock, \
+ .n = _SUNXI_CCU_MULT(_nshift, _nwidth), \
+ .m = _SUNXI_CCU_DIV(_mshift, _mwidth), \
+ .common = { \
+ .reg = _reg, \
+ .features = (CCU_FEATURE_GATE | \
+ CCU_FEATURE_PLL_LOCK), \
+ .hw.init = SUNXI_HW_INIT(_name, \
+ _parent, \
+ &ccu_nm_ops, \
+ _flags), \
+ }, \
+ }
+
+static inline struct ccu_nm *hw_to_ccu_nm(struct clk_hw *hw)
+{
+ struct ccu_common *common = hw_to_ccu_common(hw);
+
+ return container_of(common, struct ccu_nm, common);
+}
+
+extern const struct clk_ops ccu_nm_ops;
+
+#endif /* _CCU_NM_H_ */
--
2.8.3