MIPS: JZ4740: Add clock API support.

Add support for managing the clocks found on JZ4740 SoC through the
Linux clock API.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1466/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/mach-jz4740/clock.h

+/*
+ *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
+ *
+ *  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.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#ifndef __ASM_JZ4740_CLOCK_H__
+#define __ASM_JZ4740_CLOCK_H__
+
+enum jz4740_wait_mode {
+	JZ4740_WAIT_MODE_IDLE,
+	JZ4740_WAIT_MODE_SLEEP,
+};
+
+void jz4740_clock_set_wait_mode(enum jz4740_wait_mode mode);
+
+void jz4740_clock_udc_enable_auto_suspend(void);
+void jz4740_clock_udc_disable_auto_suspend(void);
+
+#endif

arch/mips/jz4740/clock-debugfs.c

+/*
+ *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
+ *  JZ4740 SoC clock support debugfs entries
+ *
+ *  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.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+
+#include <asm/mach-jz4740/clock.h>
+#include "clock.h"
+
+static struct dentry *jz4740_clock_debugfs;
+
+static int jz4740_clock_debugfs_show_enabled(void *data, uint64_t *value)
+{
+	struct clk *clk = data;
+	*value = clk_is_enabled(clk);
+
+	return 0;
+}
+
+static int jz4740_clock_debugfs_set_enabled(void *data, uint64_t value)
+{
+	struct clk *clk = data;
+
+	if (value)
+		return clk_enable(clk);
+	else
+		clk_disable(clk);
+
+	return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(jz4740_clock_debugfs_ops_enabled,
+	jz4740_clock_debugfs_show_enabled,
+	jz4740_clock_debugfs_set_enabled,
+	"%llu\n");
+
+static int jz4740_clock_debugfs_show_rate(void *data, uint64_t *value)
+{
+	struct clk *clk = data;
+	*value = clk_get_rate(clk);
+
+	return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(jz4740_clock_debugfs_ops_rate,
+	jz4740_clock_debugfs_show_rate,
+	NULL,
+	"%llu\n");
+
+void jz4740_clock_debugfs_add_clk(struct clk *clk)
+{
+	if (!jz4740_clock_debugfs)
+		return;
+
+	clk->debugfs_entry = debugfs_create_dir(clk->name, jz4740_clock_debugfs);
+	debugfs_create_file("rate", S_IWUGO | S_IRUGO, clk->debugfs_entry, clk,
+				&jz4740_clock_debugfs_ops_rate);
+	debugfs_create_file("enabled", S_IRUGO, clk->debugfs_entry, clk,
+				&jz4740_clock_debugfs_ops_enabled);
+
+	if (clk->parent) {
+		char parent_path[100];
+		snprintf(parent_path, 100, "../%s", clk->parent->name);
+		clk->debugfs_parent_entry = debugfs_create_symlink("parent",
+						clk->debugfs_entry,
+						parent_path);
+	}
+}
+
+/* TODO: Locking */
+void jz4740_clock_debugfs_update_parent(struct clk *clk)
+{
+	if (clk->debugfs_parent_entry)
+		debugfs_remove(clk->debugfs_parent_entry);
+
+	if (clk->parent) {
+		char parent_path[100];
+		snprintf(parent_path, 100, "../%s", clk->parent->name);
+		clk->debugfs_parent_entry = debugfs_create_symlink("parent",
+						clk->debugfs_entry,
+						parent_path);
+	} else {
+		clk->debugfs_parent_entry = NULL;
+	}
+}
+
+void jz4740_clock_debugfs_init(void)
+{
+	jz4740_clock_debugfs = debugfs_create_dir("jz4740-clock", NULL);
+	if (IS_ERR(jz4740_clock_debugfs))
+		jz4740_clock_debugfs = NULL;
+}

arch/mips/jz4740/clock.h

+/*
+ *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
+ *  JZ4740 SoC clock support
+ *
+ *  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.
+ *
+ *  You should have received a copy of the  GNU General Public License along
+ *  with this program; if not, write  to the Free Software Foundation, Inc.,
+ *  675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#ifndef __MIPS_JZ4740_CLOCK_H__
+#define __MIPS_JZ4740_CLOCK_H__
+
+#include <linux/list.h>
+
+struct jz4740_clock_board_data {
+	unsigned long ext_rate;
+	unsigned long rtc_rate;
+};
+
+extern struct jz4740_clock_board_data jz4740_clock_bdata;
+
+void jz4740_clock_suspend(void);
+void jz4740_clock_resume(void);
+
+struct clk;
+
+struct clk_ops {
+	unsigned long (*get_rate)(struct clk *clk);
+	unsigned long (*round_rate)(struct clk *clk, unsigned long rate);
+	int (*set_rate)(struct clk *clk, unsigned long rate);
+	int (*enable)(struct clk *clk);
+	int (*disable)(struct clk *clk);
+	int (*is_enabled)(struct clk *clk);
+
+	int (*set_parent)(struct clk *clk, struct clk *parent);
+
+};
+
+struct clk {
+	const char *name;
+	struct clk *parent;
+
+	uint32_t gate_bit;
+
+	const struct clk_ops *ops;
+
+	struct list_head list;
+
+#ifdef CONFIG_DEBUG_FS
+	struct dentry *debugfs_entry;
+	struct dentry *debugfs_parent_entry;
+#endif
+
+};
+
+#define JZ4740_CLK_NOT_GATED ((uint32_t)-1)
+
+int clk_is_enabled(struct clk *clk);
+
+#ifdef CONFIG_DEBUG_FS
+void jz4740_clock_debugfs_init(void);
+void jz4740_clock_debugfs_add_clk(struct clk *clk);
+void jz4740_clock_debugfs_update_parent(struct clk *clk);
+#else
+static inline void jz4740_clock_debugfs_init(void) {};
+static inline void jz4740_clock_debugfs_add_clk(struct clk *clk) {};
+static inline void jz4740_clock_debugfs_update_parent(struct clk *clk) {};
+#endif
+
+#endif