Thread (64 messages) 64 messages, 4 authors, 2016-06-03

[PATCH 10/16] clk: sunxi-ng: Add M-P factor clock support

From: Maxime Ripard <hidden>
Date: 2016-05-23 17:18:45
Also in: linux-clk

Hi,

On Mon, May 23, 2016 at 09:45:16PM +0800, Chen-Yu Tsai wrote:
Hi,

On Mon, May 9, 2016 at 4:01 AM, Maxime Ripard
[off-list ref] wrote:
quoted
Introduce support for the clocks that combine a linear divider and a
power-of-two based one.
A description or formula in the source code (for those of us that forget)
would be nice. :)
Ack :)
quoted
Signed-off-by: Maxime Ripard <redacted>
---
 drivers/clk/sunxi-ng/Makefile |   1 +
 drivers/clk/sunxi-ng/ccu_mp.c | 158 ++++++++++++++++++++++++++++++++++++++++++
 drivers/clk/sunxi-ng/ccu_mp.h |  79 +++++++++++++++++++++
 3 files changed, 238 insertions(+)
 create mode 100644 drivers/clk/sunxi-ng/ccu_mp.c
 create mode 100644 drivers/clk/sunxi-ng/ccu_mp.h
diff --git a/drivers/clk/sunxi-ng/Makefile b/drivers/clk/sunxi-ng/Makefile
index 063c50f35ad4..09fce7467784 100644
--- a/drivers/clk/sunxi-ng/Makefile
+++ b/drivers/clk/sunxi-ng/Makefile
@@ -5,6 +5,7 @@ obj-y += ccu_div_table.o
 obj-y += ccu_fixed_factor.o
 obj-y += ccu_gate.o
 obj-y += ccu_m.o
+obj-y += ccu_mp.o
 obj-y += ccu_mux.o
 obj-y += ccu_p.o
 obj-y += ccu_phase.o
diff --git a/drivers/clk/sunxi-ng/ccu_mp.c b/drivers/clk/sunxi-ng/ccu_mp.c
new file mode 100644
index 000000000000..7181188deba7
--- /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, cmp->m.shift);
+       reg &= ~GENMASK(cmp->p.width + cmp->p.shift, cmp->p.shift);
width + shift - 1 ? IIRC GENMASK is inclusive at both ends.
Indeed, will fix.
quoted
+
+       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
index 000000000000..95da9c46cd4f
--- /dev/null
+++ b/drivers/clk/sunxi-ng/ccu_mp.h
@@ -0,0 +1,79 @@
+/*
+ * 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_factor.h"
+#include "ccu_mux.h"
+
+struct ccu_mp {
+       u32                     enable;
+
+       struct ccu_factor       m;
+       struct ccu_factor       p;
+       struct ccu_mux_internal mux;
+       struct ccu_common       common;
+};
+
+#define SUNXI_CCU_MP_WITH_MUX(_struct, _name, _parents, _reg,          \
+                             _mshift, _mwidth,                         \
+                             _pshift, _pwidth,                         \
+                             _muxshift, _muxwidth,                     \
+                             _flags)                                   \
+       struct ccu_mp _struct = {                                       \
+               .m      = SUNXI_CLK_FACTOR(_mshift, _mwidth),           \
+               .p      = SUNXI_CLK_FACTOR(_pshift, _pwidth),           \
+               .mux    = SUNXI_CLK_MUX(_muxshift, _muxwidth),          \
+               .common = {                                             \
+                       .reg            = _reg,                         \
+                       .hw.init        = SUNXI_HW_INIT_PARENTS(_name,  \
+                                                               _parents, \
+                                                               &ccu_mp_ops, \
+                                                               _flags), \
+               }                                                       \
+       }
Use the latter to simplify this one?
quoted
+
+#define SUNXI_CCU_MP_WITH_MUX_GATE(_struct, _name, _parents, _reg,     \
We could merge _struct with _name ...
quoted
+                                  _mshift, _mwidth,                    \
+                                  _pshift, _pwidth,                    \
+                                  _muxshift, _muxwidth,                \
+                                  _gate, _flags)                       \
+       struct ccu_mp _struct = {                                       \
and have struct ccu_mp _name##_clk = {
Unfortunately, that prevents to use dashes as clock names, which is
something we've done in the past. Having a separate name allows us to
use whatever we want.

Maxime

---
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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