[PATCH v2] clk: mediatek: Export CPU mux clocks for CPU frequency control - linaro-kernel

20 Apr 2015

This patch adds CPU mux clocks which are used by Mediatek cpufreq driver for
intermediate clock source switching. It is based on v11 of common clock support
for Mediatek MT8135 and MT8173[1]
[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2015-April/335967.html
Changes in v2:
- Remove use of .determine_rate callback
Signed-off-by: pi-cheng.chen pi-cheng.chen@linaro.org
---
 drivers/clk/mediatek/Makefile          |   2 +-
 drivers/clk/mediatek/clk-cpumux.c      | 122 +++++++++++++++++++++++++++++++++
 drivers/clk/mediatek/clk-cpumux.h      |  31 +++++++++
 drivers/clk/mediatek/clk-mt8173.c      |  23 +++++++
 include/dt-bindings/clock/mt8173-clk.h |   4 +-
 5 files changed, 180 insertions(+), 2 deletions(-)
 create mode 100644 drivers/clk/mediatek/clk-cpumux.c
 create mode 100644 drivers/clk/mediatek/clk-cpumux.h

diff --git a/drivers/clk/mediatek/Makefile b/drivers/clk/mediatek/Makefile
index 8e4b2a4..299917a 100644
--- a/drivers/clk/mediatek/Makefile
+++ b/drivers/clk/mediatek/Makefile
@@ -1,4 +1,4 @@
-obj-y += clk-mtk.o clk-pll.o clk-gate.o
+obj-y += clk-mtk.o clk-pll.o clk-gate.o clk-cpumux.o
 obj-$(CONFIG_RESET_CONTROLLER) += reset.o
 obj-y += clk-mt8135.o
 obj-y += clk-mt8173.o
diff --git a/drivers/clk/mediatek/clk-cpumux.c b/drivers/clk/mediatek/clk-cpumux.c
new file mode 100644
index 0000000..dc14074
--- /dev/null
+++ b/drivers/clk/mediatek/clk-cpumux.c
@@ -0,0 +1,122 @@
+/*
+ * Copyright (c) 2015 Linaro Ltd.
+ * Author: Pi-Cheng Chen pi-cheng.chen@linaro.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.h>
+#include <linux/clk-provider.h>
+#include <linux/mfd/syscon.h>
+#include <linux/slab.h>
+
+#include "clk-mtk.h"
+#include "clk-cpumux.h"
+
+static inline struct mtk_clk_cpumux *to_clk_mux(struct clk_hw *_hw)
+{
+	return container_of(_hw, struct mtk_clk_cpumux, hw);
+}
+
+static u8 clk_cpumux_get_parent(struct clk_hw *hw)
+{
+	struct mtk_clk_cpumux *mux = to_clk_mux(hw);
+	int num_parents = __clk_get_num_parents(hw->clk);
+	u32 val;
+
+	regmap_read(mux->regmap, mux->reg, &val);
+
+	val >>= mux->shift;
+	val &= mux->mask;
+
+	if (val >= num_parents)
+		return -EINVAL;
+
+	return val;
+}
+
+static int clk_cpumux_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct mtk_clk_cpumux *mux = to_clk_mux(hw);
+	u32 mask, val;
+
+	val = index << mux->shift;
+	mask = mux->mask << mux->shift;
+
+	return regmap_update_bits(mux->regmap, mux->reg, mask, val);
+}
+
+static struct clk_ops clk_cpumux_ops = {
+	.get_parent = clk_cpumux_get_parent,
+	.set_parent = clk_cpumux_set_parent,
+};
+
+static struct clk *mtk_clk_register_cpumux(const struct mtk_composite *mux,
+					   struct regmap *regmap)
+{
+	struct mtk_clk_cpumux *cpumux;
+	struct clk *clk;
+	struct clk_init_data init;
+
+	cpumux = kzalloc(sizeof(*cpumux), GFP_KERNEL);
+	if (!cpumux)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = mux->name;
+	init.ops = &clk_cpumux_ops;
+	init.parent_names = mux->parent_names;
+	init.num_parents = mux->num_parents;
+
+	cpumux->reg = mux->mux_reg;
+	cpumux->shift = mux->mux_shift;
+	cpumux->mask = (BIT(mux->mux_width) - 1);
+	cpumux->regmap = regmap;
+	cpumux->hw.init = &init;
+
+	clk = clk_register(NULL, &cpumux->hw);
+	if (IS_ERR(clk))
+		kfree(cpumux);
+
+	return clk;
+}
+
+int mtk_clk_register_cpumuxes(struct device_node *node,
+			      const struct mtk_composite *clks, int num,
+			      struct clk_onecell_data *clk_data)
+{
+	int i;
+	struct clk *clk;
+	struct regmap *regmap;
+
+	if (!clk_data)
+		return -ENOMEM;
+
+	regmap = syscon_node_to_regmap(node);
+	if (IS_ERR(regmap)) {
+		pr_err("Cannot find regmap for %s: %ld\n", node->full_name,
+		       PTR_ERR(regmap));
+		return PTR_ERR(regmap);
+	}
+
+	for (i = 0; i < num; i++) {
+		const struct mtk_composite *mux = &clks[i];
+
+		clk = mtk_clk_register_cpumux(mux, regmap);
+		if (IS_ERR(clk)) {
+			pr_err("Failed to register clk %s: %ld\n",
+			       mux->name, PTR_ERR(clk));
+			continue;
+		}
+
+		clk_data->clks[mux->id] = clk;
+	}
+
+	return 0;
+}
diff --git a/drivers/clk/mediatek/clk-cpumux.h b/drivers/clk/mediatek/clk-cpumux.h
new file mode 100644
index 0000000..b82ad20
--- /dev/null
+++ b/drivers/clk/mediatek/clk-cpumux.h
@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2015 Linaro Ltd.
+ * Author: Pi-Cheng Chen pi-cheng.chen@linaro.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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 __DRV_CLK_CPUMUX_H
+#define __DRV_CLK_CPUMUX_H
+
+#include <linux/regmap.h>
+
+struct mtk_clk_cpumux {
+	struct clk_hw	hw;
+	struct regmap	*regmap;
+	u32		reg;
+	u32		mask;
+	u8		shift;
+};
+
+int mtk_clk_register_cpumuxes(struct device_node *node,
+			      const struct mtk_composite *clks, int num,
+			      struct clk_onecell_data *clk_data);
+#endif /* __DRV_CLK_CPUMUX_H */
diff --git a/drivers/clk/mediatek/clk-mt8173.c b/drivers/clk/mediatek/clk-mt8173.c
index 0584554..745f9d9 100644
--- a/drivers/clk/mediatek/clk-mt8173.c
+++ b/drivers/clk/mediatek/clk-mt8173.c
@@ -19,6 +19,7 @@
#include "clk-mtk.h"
 #include "clk-gate.h"
+#include "clk-cpumux.h"
#include <dt-bindings/clock/mt8173-clk.h>
@@ -517,6 +518,20 @@ static const char * const i2s3_b_ck_parents[] __initconst = {
    "apll2_div5"
 };
+static const char * const ca53_parents[] __initconst = {
+	"clk26m",
+	"armca7pll",
+	"mainpll",
+	"univpll"
+};
+
+static const char * const ca57_parents[] __initconst = {
+	"clk26m",
+	"armca15pll",
+	"mainpll",
+	"univpll"
+};
+
 static const struct mtk_composite top_muxes[] __initconst = {
    /* CLK_CFG_0 */
    MUX(TOP_AXI_SEL, "axi_sel", axi_parents, 0x0040, 0, 3),
@@ -589,6 +604,11 @@ static const struct mtk_composite top_muxes[] __initconst = {
    MUX(TOP_I2S3_B_CK_SEL, "i2s3_b_ck_sel", i2s3_b_ck_parents, 0x120, 8, 1),
 };
+static const struct mtk_composite cpu_muxes[] __initconst = {
+	MUX(INFRA_CA53SEL, "infra_ca53_sel", ca53_parents, 0x0000, 0, 2),
+	MUX(INFRA_CA57SEL, "infra_ca57_sel", ca57_parents, 0x0000, 2, 2),
+};
+
 static void __init mtk_init_clk_topckgen(void __iomem *top_base,
    	struct clk_onecell_data *clk_data)
 {
@@ -745,6 +765,9 @@ static void __init mtk_infrasys_init(struct device_node *node)
    mtk_clk_register_gates(node, infra_clks, ARRAY_SIZE(infra_clks),
    					clk_data);
+	mtk_clk_register_cpumuxes(node, cpu_muxes, ARRAY_SIZE(cpu_muxes),
+						clk_data);
+
    r = of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);
    if (r)
    	pr_err("%s(): could not register clock provider: %d\n",
diff --git a/include/dt-bindings/clock/mt8173-clk.h b/include/dt-bindings/clock/mt8173-clk.h
index e648b28..2503b03 100644
--- a/include/dt-bindings/clock/mt8173-clk.h
+++ b/include/dt-bindings/clock/mt8173-clk.h
@@ -187,7 +187,9 @@
 #define INFRA_CEC		9
 #define INFRA_PMICSPI		10
 #define INFRA_PMICWRAP		11
-#define INFRA_NR_CLK		12
+#define INFRA_CA53SEL		12
+#define INFRA_CA57SEL		13
+#define INFRA_NR_CLK		14
/* PERI_SYS */
-- 
1.9.1


    