[PATCH v3 1/2] clk: uniphier: add CPU-gear change (cpufreq) support

From: Masahiro Yamada
Date: Tue Dec 06 2016 - 20:34:41 EST

Core support code for CPU frequency changes, which will be used by
the generic cpufreq driver.

The register view is different from the generic clk-mux; it has
a separate status register, and an update bit to load the register
setting.

Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
---

Changes in v3:
- Do not use anonymous union.

Changes in v2: None

drivers/clk/uniphier/Makefile | 3 +
drivers/clk/uniphier/clk-uniphier-core.c | 3 +
drivers/clk/uniphier/clk-uniphier-cpugear.c | 115 ++++++++++++++++++++++++++++
drivers/clk/uniphier/clk-uniphier.h | 17 +++-
4 files changed, 136 insertions(+), 2 deletions(-)
create mode 100644 drivers/clk/uniphier/clk-uniphier-cpugear.c

diff --git a/drivers/clk/uniphier/Makefile b/drivers/clk/uniphier/Makefile
index f27b3603..665d1d6 100644
--- a/drivers/clk/uniphier/Makefile
+++ b/drivers/clk/uniphier/Makefile
@@ -1,8 +1,11 @@
obj-y += clk-uniphier-core.o
+
+obj-y += clk-uniphier-cpugear.o
obj-y += clk-uniphier-fixed-factor.o
obj-y += clk-uniphier-fixed-rate.o
obj-y += clk-uniphier-gate.o
obj-y += clk-uniphier-mux.o
+
obj-y += clk-uniphier-sys.o
obj-y += clk-uniphier-mio.o
obj-y += clk-uniphier-peri.o
diff --git a/drivers/clk/uniphier/clk-uniphier-core.c b/drivers/clk/uniphier/clk-uniphier-core.c
index 26c53f7..0007218 100644
--- a/drivers/clk/uniphier/clk-uniphier-core.c
+++ b/drivers/clk/uniphier/clk-uniphier-core.c
@@ -27,6 +27,9 @@ static struct clk_hw *uniphier_clk_register(struct device *dev,
const struct uniphier_clk_data *data)
{
switch (data->type) {
+ case UNIPHIER_CLK_TYPE_CPUGEAR:
+ return uniphier_clk_register_cpugear(dev, regmap, data->name,
+ &data->data.cpugear);
case UNIPHIER_CLK_TYPE_FIXED_FACTOR:
return uniphier_clk_register_fixed_factor(dev, data->name,
&data->data.factor);
diff --git a/drivers/clk/uniphier/clk-uniphier-cpugear.c b/drivers/clk/uniphier/clk-uniphier-cpugear.c
new file mode 100644
index 0000000..9bff26e
--- /dev/null
+++ b/drivers/clk/uniphier/clk-uniphier-cpugear.c
@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2016 Socionext Inc.
+ * Author: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
+ *
+ * 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.
+ *
+ * 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.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/regmap.h>
+
+#include "clk-uniphier.h"
+
+#define UNIPHIER_CLK_CPUGEAR_STAT 0 /* status */
+#define UNIPHIER_CLK_CPUGEAR_SET 4 /* set */
+#define UNIPHIER_CLK_CPUGEAR_UPD 8 /* update */
+#define UNIPHIER_CLK_CPUGEAR_UPD_BIT BIT(0)
+
+struct uniphier_clk_cpugear {
+ struct clk_hw hw;
+ struct regmap *regmap;
+ unsigned int regbase;
+ unsigned int mask;
+};
+
+#define to_uniphier_clk_cpugear(_hw) \
+ container_of(_hw, struct uniphier_clk_cpugear, hw)
+
+static int uniphier_clk_cpugear_set_parent(struct clk_hw *hw, u8 index)
+{
+ struct uniphier_clk_cpugear *gear = to_uniphier_clk_cpugear(hw);
+ int ret;
+ unsigned int val;
+
+ ret = regmap_write_bits(gear->regmap,
+ gear->regbase + UNIPHIER_CLK_CPUGEAR_SET,
+ gear->mask, index);
+ if (ret)
+ return ret;
+
+ ret = regmap_write_bits(gear->regmap,
+ gear->regbase + UNIPHIER_CLK_CPUGEAR_SET,
+ UNIPHIER_CLK_CPUGEAR_UPD_BIT,
+ UNIPHIER_CLK_CPUGEAR_UPD_BIT);
+ if (ret)
+ return ret;
+
+ return regmap_read_poll_timeout(gear->regmap,
+ gear->regbase + UNIPHIER_CLK_CPUGEAR_UPD,
+ val, !(val & UNIPHIER_CLK_CPUGEAR_UPD_BIT),
+ 0, 1);
+}
+
+static u8 uniphier_clk_cpugear_get_parent(struct clk_hw *hw)
+{
+ struct uniphier_clk_cpugear *gear = to_uniphier_clk_cpugear(hw);
+ int num_parents = clk_hw_get_num_parents(hw);
+ int ret;
+ unsigned int val;
+
+ ret = regmap_read(gear->regmap,
+ gear->regbase + UNIPHIER_CLK_CPUGEAR_STAT, &val);
+ if (ret)
+ return ret;
+
+ val &= gear->mask;
+
+ return val < num_parents ? val : -EINVAL;
+}
+
+static const struct clk_ops uniphier_clk_cpugear_ops = {
+ .determine_rate = __clk_mux_determine_rate,
+ .set_parent = uniphier_clk_cpugear_set_parent,
+ .get_parent = uniphier_clk_cpugear_get_parent,
+};
+
+struct clk_hw *uniphier_clk_register_cpugear(struct device *dev,
+ struct regmap *regmap,
+ const char *name,
+ const struct uniphier_clk_cpugear_data *data)
+{
+ struct uniphier_clk_cpugear *gear;
+ struct clk_init_data init;
+ int ret;
+
+ gear = devm_kzalloc(dev, sizeof(*gear), GFP_KERNEL);
+ if (!gear)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = name;
+ init.ops = &uniphier_clk_cpugear_ops;
+ init.flags = CLK_SET_RATE_PARENT;
+ init.parent_names = data->parent_names;
+ init.num_parents = data->num_parents,
+
+ gear->regmap = regmap;
+ gear->regbase = data->regbase;
+ gear->mask = data->mask;
+ gear->hw.init = &init;
+
+ ret = devm_clk_hw_register(dev, &gear->hw);
+ if (ret)
+ return ERR_PTR(ret);
+
+ return &gear->hw;
+}
diff --git a/drivers/clk/uniphier/clk-uniphier.h b/drivers/clk/uniphier/clk-uniphier.h
index 0244dba..9707b0f 100644
--- a/drivers/clk/uniphier/clk-uniphier.h
+++ b/drivers/clk/uniphier/clk-uniphier.h
@@ -20,15 +20,24 @@ struct clk_hw;
struct device;
struct regmap;

-#define UNIPHIER_CLK_MUX_MAX_PARENTS 8
+#define UNIPHIER_CLK_CPUGEAR_MAX_PARENTS 16
+#define UNIPHIER_CLK_MUX_MAX_PARENTS 8

enum uniphier_clk_type {
+ UNIPHIER_CLK_TYPE_CPUGEAR,
UNIPHIER_CLK_TYPE_FIXED_FACTOR,
UNIPHIER_CLK_TYPE_FIXED_RATE,
UNIPHIER_CLK_TYPE_GATE,
UNIPHIER_CLK_TYPE_MUX,
};

+struct uniphier_clk_cpugear_data {
+ const char *parent_names[UNIPHIER_CLK_CPUGEAR_MAX_PARENTS];
+ unsigned int num_parents;
+ unsigned int regbase;
+ unsigned int mask;
+};
+
struct uniphier_clk_fixed_factor_data {
const char *parent_name;
unsigned int mult;
@@ -58,6 +67,7 @@ struct uniphier_clk_data {
enum uniphier_clk_type type;
int idx;
union {
+ struct uniphier_clk_cpugear_data cpugear;
struct uniphier_clk_fixed_factor_data factor;
struct uniphier_clk_fixed_rate_data rate;
struct uniphier_clk_gate_data gate;
@@ -90,7 +100,10 @@ struct uniphier_clk_data {
}, \
}

-
+struct clk_hw *uniphier_clk_register_cpugear(struct device *dev,
+ struct regmap *regmap,
+ const char *name,
+ const struct uniphier_clk_cpugear_data *data);
struct clk_hw *uniphier_clk_register_fixed_factor(struct device *dev,
const char *name,
const struct uniphier_clk_fixed_factor_data *data);
--
2.7.4