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>

4 files changed, 1137 insertions, 0 deletions

diff --git a/arch/mips/include/asm/mach-jz4740/clock.h b/arch/mips/include/asm/mach-jz4740/clock.h
new file mode 100644
index 00000000000..1b7408dd0e2
--- /dev/null
+++ b/arch/mips/include/asm/mach-jz4740/clock.h
@@ -0,0 +1,28 @@
+/*
+ *  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
diff --git a/arch/mips/jz4740/clock-debugfs.c b/arch/mips/jz4740/clock-debugfs.c
new file mode 100644
index 00000000000..330a0f2bf17
--- /dev/null
+++ b/arch/mips/jz4740/clock-debugfs.c
@@ -0,0 +1,109 @@
+/*
+ *  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;
+}
diff --git a/arch/mips/jz4740/clock.c b/arch/mips/jz4740/clock.c
new file mode 100644
index 00000000000..118a8a5562d
--- /dev/null
+++ b/arch/mips/jz4740/clock.c
@@ -0,0 +1,924 @@
+/*
+ *  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.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/clk.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/err.h>
+
+#include <asm/mach-jz4740/clock.h>
+#include <asm/mach-jz4740/base.h>
+
+#include "clock.h"
+
+#define JZ_REG_CLOCK_CTRL	0x00
+#define JZ_REG_CLOCK_LOW_POWER	0x04
+#define JZ_REG_CLOCK_PLL	0x10
+#define JZ_REG_CLOCK_GATE	0x20
+#define JZ_REG_CLOCK_SLEEP_CTRL	0x24
+#define JZ_REG_CLOCK_I2S	0x60
+#define JZ_REG_CLOCK_LCD	0x64
+#define JZ_REG_CLOCK_MMC	0x68
+#define JZ_REG_CLOCK_UHC	0x6C
+#define JZ_REG_CLOCK_SPI	0x74
+
+#define JZ_CLOCK_CTRL_I2S_SRC_PLL	BIT(31)
+#define JZ_CLOCK_CTRL_KO_ENABLE		BIT(30)
+#define JZ_CLOCK_CTRL_UDC_SRC_PLL	BIT(29)
+#define JZ_CLOCK_CTRL_UDIV_MASK		0x1f800000
+#define JZ_CLOCK_CTRL_CHANGE_ENABLE	BIT(22)
+#define JZ_CLOCK_CTRL_PLL_HALF		BIT(21)
+#define JZ_CLOCK_CTRL_LDIV_MASK		0x001f0000
+#define JZ_CLOCK_CTRL_UDIV_OFFSET	23
+#define JZ_CLOCK_CTRL_LDIV_OFFSET	16
+#define JZ_CLOCK_CTRL_MDIV_OFFSET	12
+#define JZ_CLOCK_CTRL_PDIV_OFFSET	 8
+#define JZ_CLOCK_CTRL_HDIV_OFFSET	 4
+#define JZ_CLOCK_CTRL_CDIV_OFFSET	 0
+
+#define JZ_CLOCK_GATE_UART0	BIT(0)
+#define JZ_CLOCK_GATE_TCU	BIT(1)
+#define JZ_CLOCK_GATE_RTC	BIT(2)
+#define JZ_CLOCK_GATE_I2C	BIT(3)
+#define JZ_CLOCK_GATE_SPI	BIT(4)
+#define JZ_CLOCK_GATE_AIC	BIT(5)
+#define JZ_CLOCK_GATE_I2S	BIT(6)
+#define JZ_CLOCK_GATE_MMC	BIT(7)
+#define JZ_CLOCK_GATE_ADC	BIT(8)
+#define JZ_CLOCK_GATE_CIM	BIT(9)
+#define JZ_CLOCK_GATE_LCD	BIT(10)
+#define JZ_CLOCK_GATE_UDC	BIT(11)
+#define JZ_CLOCK_GATE_DMAC	BIT(12)
+#define JZ_CLOCK_GATE_IPU	BIT(13)
+#define JZ_CLOCK_GATE_UHC	BIT(14)
+#define JZ_CLOCK_GATE_UART1	BIT(15)
+
+#define JZ_CLOCK_I2S_DIV_MASK		0x01ff
+
+#define JZ_CLOCK_LCD_DIV_MASK		0x01ff
+
+#define JZ_CLOCK_MMC_DIV_MASK		0x001f
+
+#define JZ_CLOCK_UHC_DIV_MASK		0x000f
+
+#define JZ_CLOCK_SPI_SRC_PLL		BIT(31)
+#define JZ_CLOCK_SPI_DIV_MASK		0x000f
+
+#define JZ_CLOCK_PLL_M_MASK		0x01ff
+#define JZ_CLOCK_PLL_N_MASK		0x001f
+#define JZ_CLOCK_PLL_OD_MASK		0x0003
+#define JZ_CLOCK_PLL_STABLE		BIT(10)
+#define JZ_CLOCK_PLL_BYPASS		BIT(9)
+#define JZ_CLOCK_PLL_ENABLED		BIT(8)
+#define JZ_CLOCK_PLL_STABLIZE_MASK	0x000f
+#define JZ_CLOCK_PLL_M_OFFSET		23
+#define JZ_CLOCK_PLL_N_OFFSET		18
+#define JZ_CLOCK_PLL_OD_OFFSET		16
+
+#define JZ_CLOCK_LOW_POWER_MODE_DOZE BIT(2)
+#define JZ_CLOCK_LOW_POWER_MODE_SLEEP BIT(0)
+
+#define JZ_CLOCK_SLEEP_CTRL_SUSPEND_UHC BIT(7)
+#define JZ_CLOCK_SLEEP_CTRL_ENABLE_UDC BIT(6)
+
+static void __iomem *jz_clock_base;
+static spinlock_t jz_clock_lock;
+static LIST_HEAD(jz_clocks);
+
+struct main_clk {
+	struct clk clk;
+	uint32_t div_offset;
+};
+
+struct divided_clk {
+	struct clk clk;
+	uint32_t reg;
+	uint32_t mask;
+};
+
+struct static_clk {
+	struct clk clk;
+	unsigned long rate;
+};
+
+static uint32_t jz_clk_reg_read(int reg)
+{
+	return readl(jz_clock_base + reg);
+}
+
+static void jz_clk_reg_write_mask(int reg, uint32_t val, uint32_t mask)
+{
+	uint32_t val2;
+
+	spin_lock(&jz_clock_lock);
+	val2 = readl(jz_clock_base + reg);
+	val2 &= ~mask;
+	val2 |= val;
+	writel(val2, jz_clock_base + reg);
+	spin_unlock(&jz_clock_lock);
+}
+
+static void jz_clk_reg_set_bits(int reg, uint32_t mask)
+{
+	uint32_t val;
+
+	spin_lock(&jz_clock_lock);
+	val = readl(jz_clock_base + reg);
+	val |= mask;
+	writel(val, jz_clock_base + reg);
+	spin_unlock(&jz_clock_lock);
+}
+
+static void jz_clk_reg_clear_bits(int reg, uint32_t mask)
+{
+	uint32_t val;
+
+	spin_lock(&jz_clock_lock);
+	val = readl(jz_clock_base + reg);
+	val &= ~mask;
+	writel(val, jz_clock_base + reg);
+	spin_unlock(&jz_clock_lock);
+}
+
+static int jz_clk_enable_gating(struct clk *clk)
+{
+	if (clk->gate_bit == JZ4740_CLK_NOT_GATED)
+		return -EINVAL;
+
+	jz_clk_reg_clear_bits(JZ_REG_CLOCK_GATE, clk->gate_bit);
+	return 0;
+}
+
+static int jz_clk_disable_gating(struct clk *clk)
+{
+	if (clk->gate_bit == JZ4740_CLK_NOT_GATED)
+		return -EINVAL;
+
+	jz_clk_reg_set_bits(JZ_REG_CLOCK_GATE, clk->gate_bit);
+	return 0;
+}
+
+static int jz_clk_is_enabled_gating(struct clk *clk)
+{
+	if (clk->gate_bit == JZ4740_CLK_NOT_GATED)
+		return 1;
+
+	return !(jz_clk_reg_read(JZ_REG_CLOCK_GATE) & clk->gate_bit);
+}
+
+static unsigned long jz_clk_static_get_rate(struct clk *clk)
+{
+	return ((struct static_clk *)clk)->rate;
+}
+
+static int jz_clk_ko_enable(struct clk *clk)
+{
+	jz_clk_reg_set_bits(JZ_REG_CLOCK_CTRL, JZ_CLOCK_CTRL_KO_ENABLE);
+	return 0;
+}
+
+static int jz_clk_ko_disable(struct clk *clk)
+{
+	jz_clk_reg_clear_bits(JZ_REG_CLOCK_CTRL, JZ_CLOCK_CTRL_KO_ENABLE);
+	return 0;
+}
+
+static int jz_clk_ko_is_enabled(struct clk *clk)
+{
+	return !!(jz_clk_reg_read(JZ_REG_CLOCK_CTRL) & JZ_CLOCK_CTRL_KO_ENABLE);
+}
+
+static const int pllno[] = {1, 2, 2, 4};
+
+static unsigned long jz_clk_pll_get_rate(struct clk *clk)
+{
+	uint32_t val;
+	int m;
+	int n;
+	int od;
+
+	val = jz_clk_reg_read(JZ_REG_CLOCK_PLL);
+
+	if (val & JZ_CLOCK_PLL_BYPASS)
+		return clk_get_rate(clk->parent);
+
+	m = ((val >> 23) & 0x1ff) + 2;
+	n = ((val >> 18) & 0x1f) + 2;
+	od = (val >> 16) & 0x3;
+
+	return ((clk_get_rate(clk->parent) / n) * m) / pllno[od];
+}
+
+static unsigned long jz_clk_pll_half_get_rate(struct clk *clk)
+{
+	uint32_t reg;
+
+	reg = jz_clk_reg_read(JZ_REG_CLOCK_CTRL);
+	if (reg & JZ_CLOCK_CTRL_PLL_HALF)
+		return jz_clk_pll_get_rate(clk->parent);
+	return jz_clk_pll_get_rate(clk->parent) >> 1;
+}
+
+static const int jz_clk_main_divs[] = {1, 2, 3, 4, 6, 8, 12, 16, 24, 32};
+
+static unsigned long jz_clk_main_round_rate(struct clk *clk, unsigned long rate)
+{
+	unsigned long parent_rate = jz_clk_pll_get_rate(clk->parent);
+	int div;
+
+	div = parent_rate / rate;
+	if (div > 32)
+		return parent_rate / 32;
+	else if (div < 1)
+		return parent_rate;
+
+	div &= (0x3 << (ffs(div) - 1));
+
+	return parent_rate / div;
+}
+
+static unsigned long jz_clk_main_get_rate(struct clk *clk)
+{
+	struct main_clk *mclk = (struct main_clk *)clk;
+	uint32_t div;
+
+	div = jz_clk_reg_read(JZ_REG_CLOCK_CTRL);
+
+	div >>= mclk->div_offset;
+	div &= 0xf;
+
+	if (div >= ARRAY_SIZE(jz_clk_main_divs))
+		div = ARRAY_SIZE(jz_clk_main_divs) - 1;
+
+	return jz_clk_pll_get_rate(clk->parent) / jz_clk_main_divs[div];
+}
+
+static int jz_clk_main_set_rate(struct clk *clk, unsigned long rate)
+{
+	struct main_clk *mclk = (struct main_clk *)clk;
+	int i;
+	int div;
+	unsigned long parent_rate = jz_clk_pll_get_rate(clk->parent);
+
+	rate = jz_clk_main_round_rate(clk, rate);
+
+	div = parent_rate / rate;
+
+	i = (ffs(div) - 1) << 1;
+	if (i > 0 && !(div & BIT(i-1)))
+		i -= 1;
+
+	jz_clk_reg_write_mask(JZ_REG_CLOCK_CTRL, i << mclk->div_offset,
+				0xf << mclk->div_offset);
+
+	return 0;
+}
+
+static struct clk_ops jz_clk_static_ops = {
+	.get_rate = jz_clk_static_get_rate,
+	.enable = jz_clk_enable_gating,
+	.disable = jz_clk_disable_gating,
+	.is_enabled = jz_clk_is_enabled_gating,
+};
+
+static struct static_clk jz_clk_ext = {
+	.clk = {
+		.name = "ext",
+		.gate_bit = JZ4740_CLK_NOT_GATED,
+		.ops = &jz_clk_static_ops,
+	},
+};
+
+static struct clk_ops jz_clk_pll_ops = {
+	.get_rate = jz_clk_pll_get_rate,
+};
+
+static struct clk jz_clk_pll = {
+	.name = "pll",
+	.parent = &jz_clk_ext.clk,
+	.ops = &jz_clk_pll_ops,
+};
+
+static struct clk_ops jz_clk_pll_half_ops = {
+	.get_rate = jz_clk_pll_half_get_rate,
+};
+
+static struct clk jz_clk_pll_half = {
+	.name = "pll half",
+	.parent = &jz_clk_pll,
+	.ops = &jz_clk_pll_half_ops,
+};
+
+static const struct clk_ops jz_clk_main_ops = {
+	.get_rate = jz_clk_main_get_rate,
+	.set_rate = jz_clk_main_set_rate,
+	.round_rate = jz_clk_main_round_rate,
+};
+
+static struct main_clk jz_clk_cpu = {
+	.clk = {
+		.name = "cclk",
+		.parent = &jz_clk_pll,
+		.ops = &jz_clk_main_ops,
+	},
+	.div_offset = JZ_CLOCK_CTRL_CDIV_OFFSET,
+};
+
+static struct main_clk jz_clk_memory = {
+	.clk = {
+		.name = "mclk",
+		.parent = &jz_clk_pll,
+		.ops = &jz_clk_main_ops,
+	},
+	.div_offset = JZ_CLOCK_CTRL_MDIV_OFFSET,
+};
+
+static struct main_clk jz_clk_high_speed_peripheral = {
+	.clk = {
+		.name = "hclk",
+		.parent = &jz_clk_pll,
+		.ops = &jz_clk_main_ops,
+	},
+	.div_offset = JZ_CLOCK_CTRL_HDIV_OFFSET,
+};
+
+
+static struct main_clk jz_clk_low_speed_peripheral = {
+	.clk = {
+		.name = "pclk",
+		.parent = &jz_clk_pll,
+		.ops = &jz_clk_main_ops,
+	},
+	.div_offset = JZ_CLOCK_CTRL_PDIV_OFFSET,
+};
+
+static const struct clk_ops jz_clk_ko_ops = {
+	.enable = jz_clk_ko_enable,
+	.disable = jz_clk_ko_disable,
+	.is_enabled = jz_clk_ko_is_enabled,
+};
+
+static struct clk jz_clk_ko = {
+	.name = "cko",
+	.parent = &jz_clk_memory.clk,
+	.ops = &jz_clk_ko_ops,
+};
+
+static int jz_clk_spi_set_parent(struct clk *clk, struct clk *parent)
+{
+	if (parent == &jz_clk_pll)
+		jz_clk_reg_set_bits(JZ_CLOCK_SPI_SRC_PLL, JZ_REG_CLOCK_SPI);
+	else if (parent == &jz_clk_ext.clk)
+		jz_clk_reg_clear_bits(JZ_CLOCK_SPI_SRC_PLL, JZ_REG_CLOCK_SPI);
+	else
+		return -EINVAL;
+
+	clk->parent = parent;
+
+	return 0;
+}
+
+static int jz_clk_i2s_set_parent(struct clk *clk, struct clk *parent)
+{
+	if (parent == &jz_clk_pll_half)
+		jz_clk_reg_set_bits(JZ_REG_CLOCK_CTRL, JZ_CLOCK_CTRL_I2S_SRC_PLL);
+	else if (parent == &jz_clk_ext.clk)
+		jz_clk_reg_clear_bits(JZ_REG_CLOCK_CTRL, JZ_CLOCK_CTRL_I2S_SRC_PLL);
+	else
+		return -EINVAL;
+
+	clk->parent = parent;
+
+	return 0;
+}
+
+static int jz_clk_udc_enable(struct clk *clk)
+{
+	jz_clk_reg_set_bits(JZ_REG_CLOCK_SLEEP_CTRL,
+			JZ_CLOCK_SLEEP_CTRL_ENABLE_UDC);
+
+	return 0;
+}
+
+static int jz_clk_udc_disable(struct clk *clk)
+{
+	jz_clk_reg_clear_bits(JZ_REG_CLOCK_SLEEP_CTRL,
+			JZ_CLOCK_SLEEP_CTRL_ENABLE_UDC);
+
+	return 0;
+}
+
+static int jz_clk_udc_is_enabled(struct clk *clk)
+{
+	return !!(jz_clk_reg_read(JZ_REG_CLOCK_SLEEP_CTRL) &
+			JZ_CLOCK_SLEEP_CTRL_ENABLE_UDC);
+}
+
+static int jz_clk_udc_set_parent(struct clk *clk, struct clk *parent)
+{
+	if (parent == &jz_clk_pll_half)
+		jz_clk_reg_set_bits(JZ_REG_CLOCK_CTRL, JZ_CLOCK_CTRL_UDC_SRC_PLL);
+	else if (parent == &jz_clk_ext.clk)
+		jz_clk_reg_clear_bits(JZ_REG_CLOCK_CTRL, JZ_CLOCK_CTRL_UDC_SRC_PLL);
+	else
+		return -EINVAL;
+
+	clk->parent = parent;
+
+	return 0;
+}
+
+static int jz_clk_udc_set_rate(struct clk *clk, unsigned long rate)
+{
+	int div;
+
+	if (clk->parent == &jz_clk_ext.clk)
+		return -EINVAL;
+
+	div = clk_get_rate(clk->parent) / rate - 1;
+
+	if (div < 0)
+		div = 0;
+	else if (div > 63)
+		div = 63;
+
+	jz_clk_reg_write_mask(JZ_REG_CLOCK_CTRL, div << JZ_CLOCK_CTRL_UDIV_OFFSET,
+				JZ_CLOCK_CTRL_UDIV_MASK);
+	return 0;
+}
+
+static unsigned long jz_clk_udc_get_rate(struct clk *clk)
+{
+	int div;
+
+	if (clk->parent == &jz_clk_ext.clk)
+		return clk_get_rate(clk->parent);
+
+	div = (jz_clk_reg_read(JZ_REG_CLOCK_CTRL) & JZ_CLOCK_CTRL_UDIV_MASK);
+	div >>= JZ_CLOCK_CTRL_UDIV_OFFSET;
+	div += 1;
+
+	return clk_get_rate(clk->parent) / div;
+}
+
+static unsigned long jz_clk_divided_get_rate(struct clk *clk)
+{
+	struct divided_clk *dclk = (struct divided_clk *)clk;
+	int div;
+
+	if (clk->parent == &jz_clk_ext.clk)
+		return clk_get_rate(clk->parent);
+
+	div = (jz_clk_reg_read(dclk->reg) & dclk->mask) + 1;
+
+	return clk_get_rate(clk->parent) / div;
+}
+
+static int jz_clk_divided_set_rate(struct clk *clk, unsigned long rate)
+{
+	struct divided_clk *dclk = (struct divided_clk *)clk;
+	int div;
+
+	if (clk->parent == &jz_clk_ext.clk)
+		return -EINVAL;
+
+	div = clk_get_rate(clk->parent) / rate - 1;
+
+	if (div < 0)
+		div = 0;
+	else if (div > dclk->mask)
+		div = dclk->mask;
+
+	jz_clk_reg_write_mask(dclk->reg, div, dclk->mask);
+
+	return 0;
+}
+
+static unsigned long jz_clk_ldclk_round_rate(struct clk *clk, unsigned long rate)
+{
+	int div;
+	unsigned long parent_rate = jz_clk_pll_half_get_rate(clk->parent);
+
+	if (rate > 150000000)
+		return 150000000;
+
+	div = parent_rate / rate;
+	if (div < 1)
+		div = 1;
+	else if (div > 32)
+		div = 32;
+
+	return parent_rate / div;
+}
+
+static int jz_clk_ldclk_set_rate(struct clk *clk, unsigned long rate)
+{
+	int div;
+
+	if (rate > 150000000)
+		return -EINVAL;
+
+	div = jz_clk_pll_half_get_rate(clk->parent) / rate - 1;
+	if (div < 0)
+		div = 0;
+	else if (div > 31)
+		div = 31;
+
+	jz_clk_reg_write_mask(JZ_REG_CLOCK_CTRL, div << JZ_CLOCK_CTRL_LDIV_OFFSET,
+				JZ_CLOCK_CTRL_LDIV_MASK);
+
+	return 0;
+}
+
+static unsigned long jz_clk_ldclk_get_rate(struct clk *clk)
+{
+	int div;
+
+	div = jz_clk_reg_read(JZ_REG_CLOCK_CTRL) & JZ_CLOCK_CTRL_LDIV_MASK;
+	div >>= JZ_CLOCK_CTRL_LDIV_OFFSET;
+
+	return jz_clk_pll_half_get_rate(clk->parent) / (div + 1);
+}
+
+static const struct clk_ops jz_clk_ops_ld = {
+	.set_rate = jz_clk_ldclk_set_rate,
+	.get_rate = jz_clk_ldclk_get_rate,
+	.round_rate = jz_clk_ldclk_round_rate,
+	.enable = jz_clk_enable_gating,
+	.disable = jz_clk_disable_gating,
+	.is_enabled = jz_clk_is_enabled_gating,
+};
+
+static struct clk jz_clk_ld = {
+	.name = "lcd",
+	.gate_bit = JZ_CLOCK_GATE_LCD,
+	.parent = &jz_clk_pll_half,
+	.ops = &jz_clk_ops_ld,
+};
+
+static const struct clk_ops jz_clk_i2s_ops = {
+	.set_rate = jz_clk_divided_set_rate,
+	.get_rate = jz_clk_divided_get_rate,
+	.enable = jz_clk_enable_gating,
+	.disable = jz_clk_disable_gating,
+	.is_enabled = jz_clk_is_enabled_gating,
+	.set_parent = jz_clk_i2s_set_parent,
+};
+
+static const struct clk_ops jz_clk_spi_ops = {
+	.set_rate = jz_clk_divided_set_rate,
+	.get_rate = jz_clk_divided_get_rate,
+	.enable = jz_clk_enable_gating,
+	.disable = jz_clk_disable_gating,
+	.is_enabled = jz_clk_is_enabled_gating,
+	.set_parent = jz_clk_spi_set_parent,
+};
+
+static const struct clk_ops jz_clk_divided_ops = {
+	.set_rate = jz_clk_divided_set_rate,
+	.get_rate = jz_clk_divided_get_rate,
+	.enable = jz_clk_enable_gating,
+	.disable = jz_clk_disable_gating,
+	.is_enabled = jz_clk_is_enabled_gating,
+};
+
+static struct divided_clk jz4740_clock_divided_clks[] = {
+	[0] = {
+		.clk = {
+			.name = "i2s",
+			.parent = &jz_clk_ext.clk,
+			.gate_bit = JZ_CLOCK_GATE_I2S,
+			.ops = &jz_clk_i2s_ops,
+		},
+		.reg = JZ_REG_CLOCK_I2S,
+		.mask = JZ_CLOCK_I2S_DIV_MASK,
+	},
+	[1] = {
+		.clk = {
+			.name = "spi",
+			.parent = &jz_clk_ext.clk,
+			.gate_bit = JZ_CLOCK_GATE_SPI,
+			.ops = &jz_clk_spi_ops,
+		},
+		.reg = JZ_REG_CLOCK_SPI,
+		.mask = JZ_CLOCK_SPI_DIV_MASK,
+	},
+	[2] = {
+		.clk = {
+			.name = "lcd_pclk",
+			.parent = &jz_clk_pll_half,
+			.gate_bit = JZ4740_CLK_NOT_GATED,
+			.ops = &jz_clk_divided_ops,
+		},
+		.reg = JZ_REG_CLOCK_LCD,
+		.mask = JZ_CLOCK_LCD_DIV_MASK,
+	},
+	[3] = {
+		.clk = {
+			.name = "mmc",
+			.parent = &jz_clk_pll_half,
+			.gate_bit = JZ_CLOCK_GATE_MMC,
+			.ops = &jz_clk_divided_ops,
+		},
+		.reg = JZ_REG_CLOCK_MMC,
+		.mask = JZ_CLOCK_MMC_DIV_MASK,
+	},
+	[4] = {
+		.clk = {
+			.name = "uhc",
+			.parent = &jz_clk_pll_half,
+			.gate_bit = JZ_CLOCK_GATE_UHC,
+			.ops = &jz_clk_divided_ops,
+		},
+		.reg = JZ_REG_CLOCK_UHC,
+		.mask = JZ_CLOCK_UHC_DIV_MASK,
+	},
+};
+
+static const struct clk_ops jz_clk_udc_ops = {
+	.set_parent = jz_clk_udc_set_parent,
+	.set_rate = jz_clk_udc_set_rate,
+	.get_rate = jz_clk_udc_get_rate,
+	.enable = jz_clk_udc_enable,
+	.disable = jz_clk_udc_disable,
+	.is_enabled = jz_clk_udc_is_enabled,
+};
+
+static const struct clk_ops jz_clk_simple_ops = {
+	.enable = jz_clk_enable_gating,
+	.disable = jz_clk_disable_gating,
+	.is_enabled = jz_clk_is_enabled_gating,
+};
+
+static struct clk jz4740_clock_simple_clks[] = {
+	[0] = {
+		.name = "udc",
+		.parent = &jz_clk_ext.clk,
+		.ops = &jz_clk_udc_ops,
+	},
+	[1] = {
+		.name = "uart0",
+		.parent = &jz_clk_ext.clk,
+		.gate_bit = JZ_CLOCK_GATE_UART0,
+		.ops = &jz_clk_simple_ops,
+	},
+	[2] = {
+		.name = "uart1",
+		.parent = &jz_clk_ext.clk,
+		.gate_bit = JZ_CLOCK_GATE_UART1,
+		.ops = &jz_clk_simple_ops,
+	},
+	[3] = {
+		.name = "dma",
+		.parent = &jz_clk_high_speed_peripheral.clk,
+		.gate_bit = JZ_CLOCK_GATE_UART0,
+		.ops = &jz_clk_simple_ops,
+	},
+	[4] = {
+		.name = "ipu",
+		.parent = &jz_clk_high_speed_peripheral.clk,
+		.gate_bit = JZ_CLOCK_GATE_IPU,
+		.ops = &jz_clk_simple_ops,
+	},
+	[5] = {
+		.name = "adc",
+		.parent = &jz_clk_ext.clk,
+		.gate_bit = JZ_CLOCK_GATE_ADC,
+		.ops = &jz_clk_simple_ops,
+	},
+	[6] = {
+		.name = "i2c",
+		.parent = &jz_clk_ext.clk,
+		.gate_bit = JZ_CLOCK_GATE_I2C,
+		.ops = &jz_clk_simple_ops,
+	},
+	[7] = {
+		.name = "aic",
+		.parent = &jz_clk_ext.clk,
+		.gate_bit = JZ_CLOCK_GATE_AIC,
+		.ops = &jz_clk_simple_ops,
+	},
+};
+
+static struct static_clk jz_clk_rtc = {
+	.clk = {
+		.name = "rtc",
+		.gate_bit = JZ_CLOCK_GATE_RTC,
+		.ops = &jz_clk_static_ops,
+	},
+	.rate = 32768,
+};
+
+int clk_enable(struct clk *clk)
+{
+	if (!clk->ops->enable)
+		return -EINVAL;
+
+	return clk->ops->enable(clk);
+}
+EXPORT_SYMBOL_GPL(clk_enable);
+
+void clk_disable(struct clk *clk)
+{
+	if (clk->ops->disable)
+		clk->ops->disable(clk);
+}
+EXPORT_SYMBOL_GPL(clk_disable);
+
+int clk_is_enabled(struct clk *clk)
+{
+	if (clk->ops->is_enabled)
+		return clk->ops->is_enabled(clk);
+
+	return 1;
+}
+
+unsigned long clk_get_rate(struct clk *clk)
+{
+	if (clk->ops->get_rate)
+		return clk->ops->get_rate(clk);
+	if (clk->parent)
+		return clk_get_rate(clk->parent);
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(clk_get_rate);
+
+int clk_set_rate(struct clk *clk, unsigned long rate)
+{
+	if (!clk->ops->set_rate)
+		return -EINVAL;
+	return clk->ops->set_rate(clk, rate);
+}
+EXPORT_SYMBOL_GPL(clk_set_rate);
+
+long clk_round_rate(struct clk *clk, unsigned long rate)
+{
+	if (clk->ops->round_rate)
+		return clk->ops->round_rate(clk, rate);
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(clk_round_rate);
+
+int clk_set_parent(struct clk *clk, struct clk *parent)
+{
+	int ret;
+	int enabled;
+
+	if (!clk->ops->set_parent)
+		return -EINVAL;
+
+	enabled = clk_is_enabled(clk);
+	if (enabled)
+		clk_disable(clk);
+	ret = clk->ops->set_parent(clk, parent);
+	if (enabled)
+		clk_enable(clk);
+
+	jz4740_clock_debugfs_update_parent(clk);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(clk_set_parent);
+
+struct clk *clk_get(struct device *dev, const char *name)
+{
+	struct clk *clk;
+
+	list_for_each_entry(clk, &jz_clocks, list) {
+		if (strcmp(clk->name, name) == 0)
+			return clk;
+	}
+	return ERR_PTR(-ENXIO);
+}
+EXPORT_SYMBOL_GPL(clk_get);
+
+void clk_put(struct clk *clk)
+{
+}
+EXPORT_SYMBOL_GPL(clk_put);
+
+static inline void clk_add(struct clk *clk)
+{
+	list_add_tail(&clk->list, &jz_clocks);
+
+	jz4740_clock_debugfs_add_clk(clk);
+}
+
+static void clk_register_clks(void)
+{
+	size_t i;
+
+	clk_add(&jz_clk_ext.clk);
+	clk_add(&jz_clk_pll);
+	clk_add(&jz_clk_pll_half);
+	clk_add(&jz_clk_cpu.clk);
+	clk_add(&jz_clk_high_speed_peripheral.clk);
+	clk_add(&jz_clk_low_speed_peripheral.clk);
+	clk_add(&jz_clk_ko);
+	clk_add(&jz_clk_ld);
+	clk_add(&jz_clk_rtc.clk);
+
+	for (i = 0; i < ARRAY_SIZE(jz4740_clock_divided_clks); ++i)
+		clk_add(&jz4740_clock_divided_clks[i].clk);
+
+	for (i = 0; i < ARRAY_SIZE(jz4740_clock_simple_clks); ++i)
+		clk_add(&jz4740_clock_simple_clks[i]);
+}
+
+void jz4740_clock_set_wait_mode(enum jz4740_wait_mode mode)
+{
+	switch (mode) {
+	case JZ4740_WAIT_MODE_IDLE:
+		jz_clk_reg_clear_bits(JZ_REG_CLOCK_LOW_POWER, JZ_CLOCK_LOW_POWER_MODE_SLEEP);
+		break;
+	case JZ4740_WAIT_MODE_SLEEP:
+		jz_clk_reg_set_bits(JZ_REG_CLOCK_LOW_POWER, JZ_CLOCK_LOW_POWER_MODE_SLEEP);
+		break;
+	}
+}
+
+void jz4740_clock_udc_disable_auto_suspend(void)
+{
+	jz_clk_reg_clear_bits(JZ_REG_CLOCK_GATE, JZ_CLOCK_GATE_UDC);
+}
+EXPORT_SYMBOL_GPL(jz4740_clock_udc_disable_auto_suspend);
+
+void jz4740_clock_udc_enable_auto_suspend(void)
+{
+	jz_clk_reg_set_bits(JZ_REG_CLOCK_GATE, JZ_CLOCK_GATE_UDC);
+}
+EXPORT_SYMBOL_GPL(jz4740_clock_udc_enable_auto_suspend);
+
+void jz4740_clock_suspend(void)
+{
+	jz_clk_reg_set_bits(JZ_REG_CLOCK_GATE,
+		JZ_CLOCK_GATE_TCU | JZ_CLOCK_GATE_DMAC | JZ_CLOCK_GATE_UART0);
+
+	jz_clk_reg_clear_bits(JZ_REG_CLOCK_PLL, JZ_CLOCK_PLL_ENABLED);
+}
+
+void jz4740_clock_resume(void)
+{
+	uint32_t pll;
+
+	jz_clk_reg_set_bits(JZ_REG_CLOCK_PLL, JZ_CLOCK_PLL_ENABLED);
+
+	do {
+		pll = jz_clk_reg_read(JZ_REG_CLOCK_PLL);
+	} while (!(pll & JZ_CLOCK_PLL_STABLE));
+
+	jz_clk_reg_clear_bits(JZ_REG_CLOCK_GATE,
+		JZ_CLOCK_GATE_TCU | JZ_CLOCK_GATE_DMAC | JZ_CLOCK_GATE_UART0);
+}
+
+static int jz4740_clock_init(void)
+{
+	uint32_t val;
+
+	jz_clock_base = ioremap(JZ4740_CPM_BASE_ADDR, 0x100);
+	if (!jz_clock_base)
+		return -EBUSY;
+
+	spin_lock_init(&jz_clock_lock);
+
+	jz_clk_ext.rate = jz4740_clock_bdata.ext_rate;
+	jz_clk_rtc.rate = jz4740_clock_bdata.rtc_rate;
+
+	val = jz_clk_reg_read(JZ_REG_CLOCK_SPI);
+
+	if (val & JZ_CLOCK_SPI_SRC_PLL)
+		jz4740_clock_divided_clks[1].clk.parent = &jz_clk_pll_half;
+
+	val = jz_clk_reg_read(JZ_REG_CLOCK_CTRL);
+
+	if (val & JZ_CLOCK_CTRL_I2S_SRC_PLL)
+		jz4740_clock_divided_clks[0].clk.parent = &jz_clk_pll_half;
+
+	if (val & JZ_CLOCK_CTRL_UDC_SRC_PLL)
+		jz4740_clock_simple_clks[0].parent = &jz_clk_pll_half;
+
+	jz4740_clock_debugfs_init();
+
+	clk_register_clks();
+
+	return 0;
+}
+arch_initcall(jz4740_clock_init);
diff --git a/arch/mips/jz4740/clock.h b/arch/mips/jz4740/clock.h
new file mode 100644
index 00000000000..5d07499d746
--- /dev/null
+++ b/arch/mips/jz4740/clock.h
@@ -0,0 +1,76 @@
+/*
+ *  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