[ARM] 5474/1: U300 clocking framework

This adds the clocking framework and hooks into the clkdevice
for U300 series platforms.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-u300/clock.c

+/*
+ *
+ * arch/arm/mach-u300/clock.c
+ *
+ *
+ * Copyright (C) 2007-2009 ST-Ericsson AB
+ * License terms: GNU General Public License (GPL) version 2
+ * Define clocks in the app platform.
+ * Author: Linus Walleij <linus.walleij@stericsson.com>
+ * Author: Jonas Aaberg <jonas.aberg@stericsson.com>
+ *
+ */
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/string.h>
+#include <linux/clk.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/timer.h>
+#include <linux/io.h>
+
+#include <asm/clkdev.h>
+#include <mach/hardware.h>
+#include <mach/syscon.h>
+
+#include "clock.h"
+
+/*
+ * TODO:
+ * - move all handling of the CCR register into this file and create
+ *   a spinlock for the CCR register
+ * - switch to the clkdevice lookup mechanism that maps clocks to
+ *   device ID:s instead when it becomes available in kernel 2.6.29.
+ * - implement rate get/set for all clocks that need it.
+ */
+
+/*
+ * Syscon clock I/O registers lock so clock requests don't collide
+ * NOTE: this is a local lock only used to lock access to clock and
+ * reset registers in syscon.
+ */
+static DEFINE_SPINLOCK(syscon_clkreg_lock);
+static DEFINE_SPINLOCK(syscon_resetreg_lock);
+
+/*
+ * The clocking hierarchy currently looks like this.
+ * NOTE: the idea is NOT to show how the clocks are routed on the chip!
+ * The ideas is to show dependencies, so a clock higher up in the
+ * hierarchy has to be on in order for another clock to be on. Now,
+ * both CPU and DMA can actually be on top of the hierarchy, and that
+ * is not modeled currently. Instead we have the backbone AMBA bus on
+ * top. This bus cannot be programmed in any way but conceptually it
+ * needs to be active for the bridges and devices to transport data.
+ *
+ * Please be aware that a few clocks are hw controlled, which mean that
+ * the hw itself can turn on/off or change the rate of the clock when
+ * needed!
+ *
+ *  AMBA bus
+ *  |
+ *  +- CPU
+ *  +- NANDIF NAND Flash interface
+ *  +- SEMI Shared Memory interface
+ *  +- ISP Image Signal Processor (U335 only)
+ *  +- CDS (U335 only)
+ *  +- DMA Direct Memory Access Controller
+ *  +- AAIF APP/ACC Inteface (Mobile Scalable Link, MSL)
+ *  +- APEX
+ *  +- VIDEO_ENC AVE2/3 Video Encoder
+ *  +- XGAM Graphics Accelerator Controller
+ *  +- AHB
+ *  |
+ *  +- ahb:0 AHB Bridge
+ *  |  |
+ *  |  +- ahb:1 INTCON Interrupt controller
+ *  |  +- ahb:3 MSPRO  Memory Stick Pro controller
+ *  |  +- ahb:4 EMIF   External Memory interface
+ *  |
+ *  +- fast:0 FAST bridge
+ *  |  |
+ *  |  +- fast:1 MMCSD MMC/SD card reader controller
+ *  |  +- fast:2 I2S0  PCM I2S channel 0 controller
+ *  |  +- fast:3 I2S1  PCM I2S channel 1 controller
+ *  |  +- fast:4 I2C0  I2C channel 0 controller
+ *  |  +- fast:5 I2C1  I2C channel 1 controller
+ *  |  +- fast:6 SPI   SPI controller
+ *  |  +- fast:7 UART1 Secondary UART (U335 only)
+ *  |
+ *  +- slow:0 SLOW bridge
+ *     |
+ *     +- slow:1 SYSCON (not possible to control)
+ *     +- slow:2 WDOG Watchdog
+ *     +- slow:3 UART0 primary UART
+ *     +- slow:4 TIMER_APP Application timer - used in Linux
+ *     +- slow:5 KEYPAD controller
+ *     +- slow:6 GPIO controller
+ *     +- slow:7 RTC controller
+ *     +- slow:8 BT Bus Tracer (not used currently)
+ *     +- slow:9 EH Event Handler (not used currently)
+ *     +- slow:a TIMER_ACC Access style timer (not used currently)
+ *     +- slow:b PPM (U335 only, what is that?)
+ */
+
+/*
+ * Reset control functions. We remember if a block has been
+ * taken out of reset and don't remove the reset assertion again
+ * and vice versa. Currently we only remove resets so the
+ * enablement function is defined out.
+ */
+static void syscon_block_reset_enable(struct clk *clk)
+{
+	u16 val;
+	unsigned long iflags;
+
+	/* Not all blocks support resetting */
+	if (!clk->res_reg || !clk->res_mask)
+		return;
+	spin_lock_irqsave(&syscon_resetreg_lock, iflags);
+	val = readw(clk->res_reg);
+	val |= clk->res_mask;
+	writew(val, clk->res_reg);
+	spin_unlock_irqrestore(&syscon_resetreg_lock, iflags);
+	clk->reset = true;
+}
+
+static void syscon_block_reset_disable(struct clk *clk)
+{
+	u16 val;
+	unsigned long iflags;
+
+	/* Not all blocks support resetting */
+	if (!clk->res_reg || !clk->res_mask)
+		return;
+	spin_lock_irqsave(&syscon_resetreg_lock, iflags);
+	val = readw(clk->res_reg);
+	val &= ~clk->res_mask;
+	writew(val, clk->res_reg);
+	spin_unlock_irqrestore(&syscon_resetreg_lock, iflags);
+	clk->reset = false;
+}
+
+int __clk_get(struct clk *clk)
+{
+	u16 val;
+
+	/* The MMC and MSPRO clocks need some special set-up */
+	if (!strcmp(clk->name, "MCLK")) {
+		/* Set default MMC clock divisor to 18.9 MHz */
+		writew(0x0054U, U300_SYSCON_VBASE + U300_SYSCON_MMF0R);
+		val = readw(U300_SYSCON_VBASE + U300_SYSCON_MMCR);
+		/* Disable the MMC feedback clock */
+		val &= ~U300_SYSCON_MMCR_MMC_FB_CLK_SEL_ENABLE;
+		/* Disable MSPRO frequency */
+		val &= ~U300_SYSCON_MMCR_MSPRO_FREQSEL_ENABLE;
+		writew(val, U300_SYSCON_VBASE + U300_SYSCON_MMCR);
+	}
+	if (!strcmp(clk->name, "MSPRO")) {
+		val = readw(U300_SYSCON_VBASE + U300_SYSCON_MMCR);
+		/* Disable the MMC feedback clock */
+		val &= ~U300_SYSCON_MMCR_MMC_FB_CLK_SEL_ENABLE;
+		/* Enable MSPRO frequency */
+		val |= U300_SYSCON_MMCR_MSPRO_FREQSEL_ENABLE;
+		writew(val, U300_SYSCON_VBASE + U300_SYSCON_MMCR);
+	}
+	return 1;
+}
+EXPORT_SYMBOL(__clk_get);
+
+void __clk_put(struct clk *clk)
+{
+}
+EXPORT_SYMBOL(__clk_put);
+
+static void syscon_clk_disable(struct clk *clk)
+{
+	unsigned long iflags;
+
+	/* Don't touch the hardware controlled clocks */
+	if (clk->hw_ctrld)
+		return;
+
+	spin_lock_irqsave(&syscon_clkreg_lock, iflags);
+	writew(clk->clk_val, U300_SYSCON_VBASE + U300_SYSCON_SBCDR);
+	spin_unlock_irqrestore(&syscon_clkreg_lock, iflags);
+}
+
+static void syscon_clk_enable(struct clk *clk)
+{
+	unsigned long iflags;
+
+	/* Don't touch the hardware controlled clocks */
+	if (clk->hw_ctrld)
+		return;
+
+	spin_lock_irqsave(&syscon_clkreg_lock, iflags);
+	writew(clk->clk_val, U300_SYSCON_VBASE + U300_SYSCON_SBCER);
+	spin_unlock_irqrestore(&syscon_clkreg_lock, iflags);
+}
+
+static u16 syscon_clk_get_rate(void)
+{
+	u16 val;
+	unsigned long iflags;
+
+	spin_lock_irqsave(&syscon_clkreg_lock, iflags);
+	val = readw(U300_SYSCON_VBASE + U300_SYSCON_CCR);
+	val &= U300_SYSCON_CCR_CLKING_PERFORMANCE_MASK;
+	spin_unlock_irqrestore(&syscon_clkreg_lock, iflags);
+	return val;
+}
+
+#ifdef CONFIG_MACH_U300_USE_I2S_AS_MASTER
+static void enable_i2s0_vcxo(void)
+{
+	u16 val;
+	unsigned long iflags;
+
+	spin_lock_irqsave(&syscon_clkreg_lock, iflags);
+	/* Set I2S0 to use the VCXO 26 MHz clock */
+	val = readw(U300_SYSCON_VBASE + U300_SYSCON_CCR);
+	val |= U300_SYSCON_CCR_TURN_VCXO_ON;
+	writew(val, U300_SYSCON_VBASE + U300_SYSCON_CCR);
+	val |= U300_SYSCON_CCR_I2S0_USE_VCXO;
+	writew(val, U300_SYSCON_VBASE + U300_SYSCON_CCR);
+	val = readw(U300_SYSCON_VBASE + U300_SYSCON_CEFR);
+	val |= U300_SYSCON_CEFR_I2S0_CLK_EN;
+	writew(val, U300_SYSCON_VBASE + U300_SYSCON_CEFR);
+	spin_unlock_irqrestore(&syscon_clkreg_lock, iflags);
+}
+
+static void enable_i2s1_vcxo(void)
+{
+	u16 val;
+	unsigned long iflags;
+
+	spin_lock_irqsave(&syscon_clkreg_lock, iflags);
+	/* Set I2S1 to use the VCXO 26 MHz clock */
+	val = readw(U300_SYSCON_VBASE + U300_SYSCON_CCR);
+	val |= U300_SYSCON_CCR_TURN_VCXO_ON;
+	writew(val, U300_SYSCON_VBASE + U300_SYSCON_CCR);
+	val |= U300_SYSCON_CCR_I2S1_USE_VCXO;
+	writew(val, U300_SYSCON_VBASE + U300_SYSCON_CCR);
+	val = readw(U300_SYSCON_VBASE + U300_SYSCON_CEFR);
+	val |= U300_SYSCON_CEFR_I2S1_CLK_EN;
+	writew(val, U300_SYSCON_VBASE + U300_SYSCON_CEFR);
+	spin_unlock_irqrestore(&syscon_clkreg_lock, iflags);
+}
+
+static void disable_i2s0_vcxo(void)
+{
+	u16 val;
+	unsigned long iflags;
+
+	spin_lock_irqsave(&syscon_clkreg_lock, iflags);
+	/* Disable I2S0 use of the VCXO 26 MHz clock */
+	val = readw(U300_SYSCON_VBASE + U300_SYSCON_CCR);
+	val &= ~U300_SYSCON_CCR_I2S0_USE_VCXO;
+	writew(val, U300_SYSCON_VBASE + U300_SYSCON_CCR);
+	/* Deactivate VCXO if noone else is using VCXO */
+	if (!(val & U300_SYSCON_CCR_I2S1_USE_VCXO))
+		val &= ~U300_SYSCON_CCR_TURN_VCXO_ON;
+	writew(val, U300_SYSCON_VBASE + U300_SYSCON_CCR);
+	val = readw(U300_SYSCON_VBASE + U300_SYSCON_CEFR);
+	val &= ~U300_SYSCON_CEFR_I2S0_CLK_EN;
+	writew(val, U300_SYSCON_VBASE + U300_SYSCON_CEFR);
+	spin_unlock_irqrestore(&syscon_clkreg_lock, iflags);
+}
+
+static void disable_i2s1_vcxo(void)
+{
+	u16 val;
+	unsigned long iflags;
+
+	spin_lock_irqsave(&syscon_clkreg_lock, iflags);
+	/* Disable I2S1 use of the VCXO 26 MHz clock */
+	val = readw(U300_SYSCON_VBASE + U300_SYSCON_CCR);
+	val &= ~U300_SYSCON_CCR_I2S1_USE_VCXO;
+	writew(val, U300_SYSCON_VBASE + U300_SYSCON_CCR);
+	/* Deactivate VCXO if noone else is using VCXO */
+	if (!(val & U300_SYSCON_CCR_I2S0_USE_VCXO))
+		val &= ~U300_SYSCON_CCR_TURN_VCXO_ON;
+	writew(val, U300_SYSCON_VBASE + U300_SYSCON_CCR);
+	val = readw(U300_SYSCON_VBASE + U300_SYSCON_CEFR);
+	val &= ~U300_SYSCON_CEFR_I2S0_CLK_EN;
+	writew(val, U300_SYSCON_VBASE + U300_SYSCON_CEFR);
+	spin_unlock_irqrestore(&syscon_clkreg_lock, iflags);
+}
+#endif /* CONFIG_MACH_U300_USE_I2S_AS_MASTER */
+
+
+static void syscon_clk_rate_set_mclk(unsigned long rate)
+{
+	u16 val;
+	u32 reg;
+	unsigned long iflags;
+
+	switch (rate) {
+	case 18900000:
+		val = 0x0054;
+		break;
+	case 20800000:
+		val = 0x0044;
+		break;
+	case 23100000:
+		val = 0x0043;
+		break;
+	case 26000000:
+		val = 0x0033;
+		break;
+	case 29700000:
+		val = 0x0032;
+		break;
+	case 34700000:
+		val = 0x0022;
+		break;
+	case 41600000:
+		val = 0x0021;
+		break;
+	case 52000000:
+		val = 0x0011;
+		break;
+	case 104000000:
+		val = 0x0000;
+		break;
+	default:
+		printk(KERN_ERR "Trying to set MCLK to unknown speed! %ld\n",
+		       rate);
+		return;
+	}
+
+	spin_lock_irqsave(&syscon_clkreg_lock, iflags);
+	reg = readw(U300_SYSCON_VBASE + U300_SYSCON_MMF0R) &
+		~U300_SYSCON_MMF0R_MASK;
+	writew(reg | val, U300_SYSCON_VBASE + U300_SYSCON_MMF0R);
+	spin_unlock_irqrestore(&syscon_clkreg_lock, iflags);
+}
+
+void syscon_clk_rate_set_cpuclk(unsigned long rate)
+{
+	u16 val;
+	unsigned long iflags;
+
+	switch (rate) {
+	case 13000000:
+		val = U300_SYSCON_CCR_CLKING_PERFORMANCE_LOW_POWER;
+		break;
+	case 52000000:
+		val = U300_SYSCON_CCR_CLKING_PERFORMANCE_INTERMEDIATE;
+		break;
+	case 104000000:
+		val = U300_SYSCON_CCR_CLKING_PERFORMANCE_HIGH;
+		break;
+	case 208000000:
+		val = U300_SYSCON_CCR_CLKING_PERFORMANCE_BEST;
+		break;
+	default:
+		return;
+	}
+	spin_lock_irqsave(&syscon_clkreg_lock, iflags);
+	val |= readw(U300_SYSCON_VBASE + U300_SYSCON_CCR) &
+		~U300_SYSCON_CCR_CLKING_PERFORMANCE_MASK ;
+	writew(val, U300_SYSCON_VBASE + U300_SYSCON_CCR);
+	spin_unlock_irqrestore(&syscon_clkreg_lock, iflags);
+}
+EXPORT_SYMBOL(syscon_clk_rate_set_cpuclk);
+
+void clk_disable(struct clk *clk)
+{
+	unsigned long iflags;
+
+	spin_lock_irqsave(&clk->lock, iflags);
+	if (clk->usecount > 0 && !(--clk->usecount)) {
+		/* some blocks lack clocking registers and cannot be disabled */
+		if (clk->disable)
+			clk->disable(clk);
+		if (likely((u32)clk->parent))
+			clk_disable(clk->parent);
+	}
+#ifdef CONFIG_MACH_U300_USE_I2S_AS_MASTER
+	if (unlikely(!strcmp(clk->name, "I2S0")))
+		disable_i2s0_vcxo();
+	if (unlikely(!strcmp(clk->name, "I2S1")))
+		disable_i2s1_vcxo();
+#endif
+	spin_unlock_irqrestore(&clk->lock, iflags);
+}
+EXPORT_SYMBOL(clk_disable);
+
+int clk_enable(struct clk *clk)
+{
+	int ret = 0;
+	unsigned long iflags;
+
+	spin_lock_irqsave(&clk->lock, iflags);
+	if (clk->usecount++ == 0) {
+		if (likely((u32)clk->parent))
+			ret = clk_enable(clk->parent);
+
+		if (unlikely(ret != 0))
+			clk->usecount--;
+		else {
+			/* remove reset line (we never enable reset again) */
+			syscon_block_reset_disable(clk);
+			/* clocks without enable function are always on */
+			if (clk->enable)
+				clk->enable(clk);
+#ifdef CONFIG_MACH_U300_USE_I2S_AS_MASTER
+			if (unlikely(!strcmp(clk->name, "I2S0")))
+				enable_i2s0_vcxo();
+			if (unlikely(!strcmp(clk->name, "I2S1")))
+				enable_i2s1_vcxo();
+#endif
+		}
+	}
+	spin_unlock_irqrestore(&clk->lock, iflags);
+	return ret;
+
+}
+EXPORT_SYMBOL(clk_enable);
+
+/* Returns the clock rate in Hz */
+static unsigned long clk_get_rate_cpuclk(struct clk *clk)
+{
+	u16 val;
+
+	val = syscon_clk_get_rate();
+
+	switch (val) {
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_LOW_POWER:
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_LOW:
+		return 13000000;
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_INTERMEDIATE:
+		return 52000000;
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_HIGH:
+		return 104000000;
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_BEST:
+		return 208000000;
+	default:
+		break;
+	}
+	return clk->rate;
+}
+
+static unsigned long clk_get_rate_ahb_clk(struct clk *clk)
+{
+	u16 val;
+
+	val = syscon_clk_get_rate();
+
+	switch (val) {
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_LOW_POWER:
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_LOW:
+		return 6500000;
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_INTERMEDIATE:
+		return 26000000;
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_HIGH:
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_BEST:
+		return 52000000;
+	default:
+		break;
+	}
+	return clk->rate;
+
+}
+
+static unsigned long clk_get_rate_emif_clk(struct clk *clk)
+{
+	u16 val;
+
+	val = syscon_clk_get_rate();
+
+	switch (val) {
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_LOW_POWER:
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_LOW:
+		return 13000000;
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_INTERMEDIATE:
+		return 52000000;
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_HIGH:
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_BEST:
+		return 104000000;
+	default:
+		break;
+	}
+	return clk->rate;
+
+}
+
+static unsigned long clk_get_rate_xgamclk(struct clk *clk)
+{
+	u16 val;
+
+	val = syscon_clk_get_rate();
+
+	switch (val) {
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_LOW_POWER:
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_LOW:
+		return 6500000;
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_INTERMEDIATE:
+		return 26000000;
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_HIGH:
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_BEST:
+		return 52000000;
+	default:
+		break;
+	}
+
+	return clk->rate;
+}
+
+static unsigned long clk_get_rate_mclk(struct clk *clk)
+{
+	u16 val;
+
+	val = syscon_clk_get_rate();
+
+	switch (val) {
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_LOW_POWER:
+		/*
+		 * Here, the 208 MHz PLL gets shut down and the always
+		 * on 13 MHz PLL used for RTC etc kicks into use
+		 * instead.
+		 */
+		return 13000000;
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_LOW:
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_INTERMEDIATE:
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_HIGH:
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_BEST:
+	{
+		/*
+		 * This clock is under program control. The register is
+		 * divided in two nybbles, bit 7-4 gives cycles-1 to count
+		 * high, bit 3-0 gives cycles-1 to count low. Distribute
+		 * these with no more than 1 cycle difference between
+		 * low and high and add low and high to get the actual
+		 * divisor. The base PLL is 208 MHz. Writing 0x00 will
+		 * divide by 1 and 1 so the highest frequency possible
+		 * is 104 MHz.
+		 *
+		 * e.g. 0x54 =>
+		 * f = 208 / ((5+1) + (4+1)) = 208 / 11 = 18.9 MHz
+		 */
+		u16 val = readw(U300_SYSCON_VBASE + U300_SYSCON_MMF0R) &
+			U300_SYSCON_MMF0R_MASK;
+		switch (val) {
+		case 0x0054:
+			return 18900000;
+		case 0x0044:
+			return 20800000;
+		case 0x0043:
+			return 23100000;
+		case 0x0033:
+			return 26000000;
+		case 0x0032:
+			return 29700000;
+		case 0x0022:
+			return 34700000;
+		case 0x0021:
+			return 41600000;
+		case 0x0011:
+			return 52000000;
+		case 0x0000:
+			return 104000000;
+		default:
+			break;
+		}
+	}
+	default:
+		break;
+	}
+
+	return clk->rate;
+}
+
+static unsigned long clk_get_rate_i2s_i2c_spi(struct clk *clk)
+{
+	u16 val;
+
+	val = syscon_clk_get_rate();
+
+	switch (val) {
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_LOW_POWER:
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_LOW:
+		return 13000000;
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_INTERMEDIATE:
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_HIGH:
+	case U300_SYSCON_CCR_CLKING_PERFORMANCE_BEST:
+		return 26000000;
+	default:
+		break;
+	}
+
+	return clk->rate;
+}
+
+unsigned long clk_get_rate(struct clk *clk)
+{
+	if (clk->get_rate)
+		return clk->get_rate(clk);
+	else
+		return clk->rate;
+}
+EXPORT_SYMBOL(clk_get_rate);
+
+static unsigned long clk_round_rate_mclk(struct clk *clk, unsigned long rate)
+{
+	if (rate >= 18900000)
+		return 18900000;
+	if (rate >= 20800000)
+		return 20800000;
+	if (rate >= 23100000)
+		return 23100000;
+	if (rate >= 26000000)
+		return 26000000;
+	if (rate >= 29700000)
+		return 29700000;
+	if (rate >= 34700000)
+		return 34700000;
+	if (rate >= 41600000)
+		return 41600000;
+	if (rate >= 52000000)
+		return 52000000;
+	return -EINVAL;
+}
+
+static unsigned long clk_round_rate_cpuclk(struct clk *clk, unsigned long rate)
+{
+	if (rate >= 13000000)
+		return 13000000;
+	if (rate >= 52000000)
+		return 52000000;
+	if (rate >= 104000000)
+		return 104000000;
+	if (rate >= 208000000)
+		return 208000000;
+	return -EINVAL;
+}
+
+/*
+ * This adjusts a requested rate to the closest exact rate
+ * a certain clock can provide. For a fixed clock it's
+ * mostly clk->rate.
+ */
+long clk_round_rate(struct clk *clk, unsigned long rate)
+{
+	/* TODO: get apropriate switches for EMIFCLK, AHBCLK and MCLK */
+	/* Else default to fixed value */
+
+	if (clk->round_rate) {
+		return (long) clk->round_rate(clk, rate);
+	} else {
+		printk(KERN_ERR "clock: Failed to round rate of %s\n",
+		       clk->name);
+	}
+	return (long) clk->rate;
+}
+EXPORT_SYMBOL(clk_round_rate);
+
+static int clk_set_rate_mclk(struct clk *clk, unsigned long rate)
+{
+	syscon_clk_rate_set_mclk(clk_round_rate(clk, rate));
+	return 0;
+}
+
+static int clk_set_rate_cpuclk(struct clk *clk, unsigned long rate)
+{
+	syscon_clk_rate_set_cpuclk(clk_round_rate(clk, rate));
+	return 0;
+}
+
+int clk_set_rate(struct clk *clk, unsigned long rate)
+{
+	/* TODO: set for EMIFCLK and AHBCLK */
+	/* Else assume the clock is fixed and fail */
+	if (clk->set_rate) {
+		return clk->set_rate(clk, rate);
+	} else {
+		printk(KERN_ERR "clock: Failed to set %s to %ld hz\n",
+		       clk->name, rate);
+		return -1;
+	}
+}
+EXPORT_SYMBOL(clk_set_rate);
+
+/*
+ * Clock definitions. The clock parents are set to respective
+ * bridge and the clock framework makes sure that the clocks have
+ * parents activated and are brought out of reset when in use.
+ *
+ * Clocks that have hw_ctrld = true are hw controlled, and the hw
+ * can by itself turn these clocks on and off.
+ * So in other words, we don't really have to care about them.
+ */
+
+static struct clk amba_clk = {
+	.name	    = "AMBA",
+	.rate	    = 52000000, /* this varies! */
+	.hw_ctrld   = true,
+	.reset	    = false,
+};
+
+/*
+ * These blocks are connected directly to the AMBA bus
+ * with no bridge.
+ */
+
+static struct clk cpu_clk = {
+	.name	    = "CPU",
+	.parent	    = &amba_clk,
+	.rate	    = 208000000, /* this varies! */
+	.hw_ctrld   = true,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RRR,
+	.res_mask   = U300_SYSCON_RRR_CPU_RESET_EN,
+	.set_rate   = clk_set_rate_cpuclk,
+	.get_rate   = clk_get_rate_cpuclk,
+	.round_rate = clk_round_rate_cpuclk,
+};
+
+static struct clk nandif_clk = {
+	.name       = "NANDIF",
+	.parent	    = &amba_clk,
+	.hw_ctrld   = false,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RRR,
+	.res_mask   = U300_SYSCON_RRR_NANDIF_RESET_EN,
+	.clk_val    = U300_SYSCON_SBCER_NANDIF_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+};
+
+static struct clk semi_clk = {
+	.name       = "SEMI",
+	.parent	    = &amba_clk,
+	.rate       = 0, /* FIXME */
+	/* It is not possible to reset SEMI */
+	.hw_ctrld   = false,
+	.reset	    = false,
+	.clk_val    = U300_SYSCON_SBCER_SEMI_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+};
+
+#ifdef CONFIG_MACH_U300_BS335
+static struct clk isp_clk = {
+	.name	    = "ISP",
+	.parent	    = &amba_clk,
+	.rate	    = 0, /* FIXME */
+	.hw_ctrld   = false,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RRR,
+	.res_mask   = U300_SYSCON_RRR_ISP_RESET_EN,
+	.clk_val    = U300_SYSCON_SBCER_ISP_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+};
+
+static struct clk cds_clk = {
+	.name	    = "CDS",
+	.parent	    = &amba_clk,
+	.rate	    = 0, /* FIXME */
+	.hw_ctrld   = false,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RRR,
+	.res_mask   = U300_SYSCON_RRR_CDS_RESET_EN,
+	.clk_val    = U300_SYSCON_SBCER_CDS_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+};
+#endif
+
+static struct clk dma_clk = {
+	.name       = "DMA",
+	.parent	    = &amba_clk,
+	.rate       = 52000000, /* this varies! */
+	.hw_ctrld   = true,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RRR,
+	.res_mask   = U300_SYSCON_RRR_DMAC_RESET_EN,
+	.clk_val    = U300_SYSCON_SBCER_DMAC_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+};
+
+static struct clk aaif_clk = {
+	.name       = "AAIF",
+	.parent	    = &amba_clk,
+	.rate       = 52000000, /* this varies! */
+	.hw_ctrld   = true,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RRR,
+	.res_mask   = U300_SYSCON_RRR_AAIF_RESET_EN,
+	.clk_val    = U300_SYSCON_SBCER_AAIF_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+};
+
+static struct clk apex_clk = {
+	.name       = "APEX",
+	.parent	    = &amba_clk,
+	.rate       = 0, /* FIXME */
+	.hw_ctrld   = true,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RRR,
+	.res_mask   = U300_SYSCON_RRR_APEX_RESET_EN,
+	.clk_val    = U300_SYSCON_SBCER_APEX_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+};
+
+static struct clk video_enc_clk = {
+	.name       = "VIDEO_ENC",
+	.parent	    = &amba_clk,
+	.rate       = 208000000, /* this varies! */
+	.hw_ctrld   = false,
+	.reset	    = false,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RRR,
+	/* This has XGAM in the name but refers to the video encoder */
+	.res_mask   = U300_SYSCON_RRR_XGAM_VC_SYNC_RESET_EN,
+	.clk_val    = U300_SYSCON_SBCER_VIDEO_ENC_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+};
+
+static struct clk xgam_clk = {
+	.name       = "XGAMCLK",
+	.parent	    = &amba_clk,
+	.rate       = 52000000, /* this varies! */
+	.hw_ctrld   = false,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RRR,
+	.res_mask   = U300_SYSCON_RRR_XGAM_RESET_EN,
+	.clk_val    = U300_SYSCON_SBCER_XGAM_CLK_EN,
+	.get_rate   = clk_get_rate_xgamclk,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+};
+
+/* This clock is used to activate the video encoder */
+static struct clk ahb_clk = {
+	.name	    = "AHB",
+	.parent	    = &amba_clk,
+	.rate	    = 52000000, /* this varies! */
+	.hw_ctrld   = false, /* This one is set to false due to HW bug */
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RRR,
+	.res_mask   = U300_SYSCON_RRR_AHB_RESET_EN,
+	.clk_val    = U300_SYSCON_SBCER_AHB_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+	.get_rate   = clk_get_rate_ahb_clk,
+};
+
+
+/*
+ * Clocks on the AHB bridge
+ */
+
+static struct clk ahb_subsys_clk = {
+	.name	    = "AHB_SUBSYS",
+	.parent	    = &amba_clk,
+	.rate	    = 52000000, /* this varies! */
+	.hw_ctrld   = true,
+	.reset	    = false,
+	.clk_val    = U300_SYSCON_SBCER_AHB_SUBSYS_BRIDGE_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+	.get_rate   = clk_get_rate_ahb_clk,
+};
+
+static struct clk intcon_clk = {
+	.name	    = "INTCON",
+	.parent	    = &ahb_subsys_clk,
+	.rate	    = 52000000, /* this varies! */
+	.hw_ctrld   = false,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RRR,
+	.res_mask   = U300_SYSCON_RRR_INTCON_RESET_EN,
+	/* INTCON can be reset but not clock-gated */
+};
+
+static struct clk mspro_clk = {
+	.name       = "MSPRO",
+	.parent	    = &ahb_subsys_clk,
+	.rate       = 0, /* FIXME */
+	.hw_ctrld   = false,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RRR,
+	.res_mask   = U300_SYSCON_RRR_MSPRO_RESET_EN,
+	.clk_val    = U300_SYSCON_SBCER_MSPRO_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+};
+
+static struct clk emif_clk = {
+	.name	    = "EMIF",
+	.parent	    = &ahb_subsys_clk,
+	.rate	    = 104000000, /* this varies! */
+	.hw_ctrld   = false,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RRR,
+	.res_mask   = U300_SYSCON_RRR_EMIF_RESET_EN,
+	.clk_val    = U300_SYSCON_SBCER_EMIF_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+	.get_rate   = clk_get_rate_emif_clk,
+};
+
+
+/*
+ * Clocks on the FAST bridge
+ */
+static struct clk fast_clk = {
+	.name	    = "FAST_BRIDGE",
+	.parent	    = &amba_clk,
+	.rate	    = 13000000, /* this varies! */
+	.hw_ctrld   = true,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RFR,
+	.res_mask   = U300_SYSCON_RFR_FAST_BRIDGE_RESET_ENABLE,
+	.clk_val    = U300_SYSCON_SBCER_FAST_BRIDGE_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+};
+
+static struct clk mmcsd_clk = {
+	.name       = "MCLK",
+	.parent	    = &fast_clk,
+	.rate       = 18900000, /* this varies! */
+	.hw_ctrld   = false,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RFR,
+	.res_mask   = U300_SYSCON_RFR_MMC_RESET_ENABLE,
+	.clk_val    = U300_SYSCON_SBCER_MMC_CLK_EN,
+	.get_rate   = clk_get_rate_mclk,
+	.set_rate   = clk_set_rate_mclk,
+	.round_rate = clk_round_rate_mclk,
+	.disable    = syscon_clk_disable,
+	.enable     = syscon_clk_enable,
+};
+
+static struct clk i2s0_clk = {
+	.name       = "i2s0",
+	.parent	    = &fast_clk,
+	.rate       = 26000000, /* this varies! */
+	.hw_ctrld   = true,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RFR,
+	.res_mask   = U300_SYSCON_RFR_PCM_I2S0_RESET_ENABLE,
+	.clk_val    = U300_SYSCON_SBCER_I2S0_CORE_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+	.get_rate   = clk_get_rate_i2s_i2c_spi,
+};
+
+static struct clk i2s1_clk = {
+	.name       = "i2s1",
+	.parent	    = &fast_clk,
+	.rate       = 26000000, /* this varies! */
+	.hw_ctrld   = true,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RFR,
+	.res_mask   = U300_SYSCON_RFR_PCM_I2S1_RESET_ENABLE,
+	.clk_val    = U300_SYSCON_SBCER_I2S1_CORE_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+	.get_rate   = clk_get_rate_i2s_i2c_spi,
+};
+
+static struct clk i2c0_clk = {
+	.name       = "I2C0",
+	.parent	    = &fast_clk,
+	.rate       = 26000000, /* this varies! */
+	.hw_ctrld   = false,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RFR,
+	.res_mask   = U300_SYSCON_RFR_I2C0_RESET_ENABLE,
+	.clk_val    = U300_SYSCON_SBCER_I2C0_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+	.get_rate   = clk_get_rate_i2s_i2c_spi,
+};
+
+static struct clk i2c1_clk = {
+	.name       = "I2C1",
+	.parent	    = &fast_clk,
+	.rate       = 26000000, /* this varies! */
+	.hw_ctrld   = false,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RFR,
+	.res_mask   = U300_SYSCON_RFR_I2C1_RESET_ENABLE,
+	.clk_val    = U300_SYSCON_SBCER_I2C1_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+	.get_rate   = clk_get_rate_i2s_i2c_spi,
+};
+
+static struct clk spi_clk = {
+	.name       = "SPI",
+	.parent	    = &fast_clk,
+	.rate       = 26000000, /* this varies! */
+	.hw_ctrld   = false,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RFR,
+	.res_mask   = U300_SYSCON_RFR_SPI_RESET_ENABLE,
+	.clk_val    = U300_SYSCON_SBCER_SPI_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+	.get_rate   = clk_get_rate_i2s_i2c_spi,
+};
+
+#ifdef CONFIG_MACH_U300_BS335
+static struct clk uart1_clk = {
+	.name	    = "UART1",
+	.parent	    = &fast_clk,
+	.rate	    = 13000000,
+	.hw_ctrld   = false,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RFR,
+	.res_mask   = U300_SYSCON_RFR_UART1_RESET_ENABLE,
+	.clk_val    = U300_SYSCON_SBCER_UART1_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+};
+#endif
+
+
+/*
+ * Clocks on the SLOW bridge
+ */
+static struct clk slow_clk = {
+	.name	    = "SLOW_BRIDGE",
+	.parent	    = &amba_clk,
+	.rate	    = 13000000,
+	.hw_ctrld   = true,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RSR,
+	.res_mask   = U300_SYSCON_RSR_SLOW_BRIDGE_RESET_EN,
+	.clk_val    = U300_SYSCON_SBCER_SLOW_BRIDGE_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+};
+
+/* TODO: implement SYSCON clock? */
+
+static struct clk wdog_clk = {
+	.name	    = "WDOG",
+	.parent	    = &slow_clk,
+	.hw_ctrld   = false,
+	.rate	    = 32768,
+	.reset	    = false,
+	/* This is always on, cannot be enabled/disabled or reset */
+};
+
+/* This one is hardwired to PLL13 */
+static struct clk uart_clk = {
+	.name	    = "UARTCLK",
+	.parent	    = &slow_clk,
+	.rate	    = 13000000,
+	.hw_ctrld   = false,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RSR,
+	.res_mask   = U300_SYSCON_RSR_UART_RESET_EN,
+	.clk_val    = U300_SYSCON_SBCER_UART_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+};
+
+static struct clk keypad_clk = {
+	.name       = "KEYPAD",
+	.parent	    = &slow_clk,
+	.rate       = 32768,
+	.hw_ctrld   = false,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RSR,
+	.res_mask   = U300_SYSCON_RSR_KEYPAD_RESET_EN,
+	.clk_val    = U300_SYSCON_SBCER_KEYPAD_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+};
+
+static struct clk gpio_clk = {
+	.name       = "GPIO",
+	.parent	    = &slow_clk,
+	.rate       = 13000000,
+	.hw_ctrld   = true,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RSR,
+	.res_mask   = U300_SYSCON_RSR_GPIO_RESET_EN,
+	.clk_val    = U300_SYSCON_SBCER_GPIO_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+};
+
+static struct clk rtc_clk = {
+	.name	    = "RTC",
+	.parent	    = &slow_clk,
+	.rate	    = 32768,
+	.hw_ctrld   = true,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RSR,
+	.res_mask   = U300_SYSCON_RSR_RTC_RESET_EN,
+	/* This clock is always on, cannot be enabled/disabled */
+};
+
+static struct clk bustr_clk = {
+	.name       = "BUSTR",
+	.parent	    = &slow_clk,
+	.rate       = 13000000,
+	.hw_ctrld   = true,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RSR,
+	.res_mask   = U300_SYSCON_RSR_BTR_RESET_EN,
+	.clk_val    = U300_SYSCON_SBCER_BTR_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+};
+
+static struct clk evhist_clk = {
+	.name       = "EVHIST",
+	.parent	    = &slow_clk,
+	.rate       = 13000000,
+	.hw_ctrld   = true,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RSR,
+	.res_mask   = U300_SYSCON_RSR_EH_RESET_EN,
+	.clk_val    = U300_SYSCON_SBCER_EH_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+};
+
+static struct clk timer_clk = {
+	.name       = "TIMER",
+	.parent	    = &slow_clk,
+	.rate       = 13000000,
+	.hw_ctrld   = true,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RSR,
+	.res_mask   = U300_SYSCON_RSR_ACC_TMR_RESET_EN,
+	.clk_val    = U300_SYSCON_SBCER_ACC_TMR_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+};
+
+static struct clk app_timer_clk = {
+	.name       = "TIMER_APP",
+	.parent	    = &slow_clk,
+	.rate       = 13000000,
+	.hw_ctrld   = true,
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RSR,
+	.res_mask   = U300_SYSCON_RSR_APP_TMR_RESET_EN,
+	.clk_val    = U300_SYSCON_SBCER_APP_TMR_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+};
+
+#ifdef CONFIG_MACH_U300_BS335
+static struct clk ppm_clk = {
+	.name	    = "PPM",
+	.parent	    = &slow_clk,
+	.rate	    = 0, /* FIXME */
+	.hw_ctrld   = true, /* TODO: Look up if it is hw ctrld or not */
+	.reset	    = true,
+	.res_reg    = U300_SYSCON_VBASE + U300_SYSCON_RSR,
+	.res_mask   = U300_SYSCON_RSR_PPM_RESET_EN,
+	.clk_val    = U300_SYSCON_SBCER_PPM_CLK_EN,
+	.enable     = syscon_clk_enable,
+	.disable    = syscon_clk_disable,
+};
+#endif
+
+#define DEF_LOOKUP(devid, clkref)		\
+	{					\
+	.dev_id = devid,			\
+	.clk = clkref,				\
+	}
+
+/*
+ * Here we only define clocks that are meaningful to
+ * look up through clockdevice.
+ */
+static struct clk_lookup lookups[] = {
+	/* Connected directly to the AMBA bus */
+	DEF_LOOKUP("amba", &amba_clk),
+	DEF_LOOKUP("cpu", &cpu_clk),
+	DEF_LOOKUP("nandif", &nandif_clk),
+	DEF_LOOKUP("semi", &semi_clk),
+#ifdef CONFIG_MACH_U300_BS335
+	DEF_LOOKUP("isp", &isp_clk),
+	DEF_LOOKUP("cds", &cds_clk),
+#endif
+	DEF_LOOKUP("dma", &dma_clk),
+	DEF_LOOKUP("aaif", &aaif_clk),
+	DEF_LOOKUP("apex", &apex_clk),
+	DEF_LOOKUP("video_enc", &video_enc_clk),
+	DEF_LOOKUP("xgam", &xgam_clk),
+	DEF_LOOKUP("ahb", &ahb_clk),
+	/* AHB bridge clocks */
+	DEF_LOOKUP("ahb", &ahb_subsys_clk),
+	DEF_LOOKUP("intcon", &intcon_clk),
+	DEF_LOOKUP("mspro", &mspro_clk),
+	DEF_LOOKUP("pl172", &emif_clk),
+	/* FAST bridge clocks */
+	DEF_LOOKUP("fast", &fast_clk),
+	DEF_LOOKUP("mmci", &mmcsd_clk),
+	/*
+	 * The .0 and .1 identifiers on these comes from the platform device
+	 * .id field and are assigned when the platform devices are registered.
+	 */
+	DEF_LOOKUP("i2s.0", &i2s0_clk),
+	DEF_LOOKUP("i2s.1", &i2s1_clk),
+	DEF_LOOKUP("stddci2c.0", &i2c0_clk),
+	DEF_LOOKUP("stddci2c.1", &i2c1_clk),
+	DEF_LOOKUP("pl022", &spi_clk),
+#ifdef CONFIG_MACH_U300_BS335
+	DEF_LOOKUP("uart1", &uart1_clk),
+#endif
+	/* SLOW bridge clocks */
+	DEF_LOOKUP("slow", &slow_clk),
+	DEF_LOOKUP("wdog", &wdog_clk),
+	DEF_LOOKUP("uart0", &uart_clk),
+	DEF_LOOKUP("apptimer", &app_timer_clk),
+	DEF_LOOKUP("keypad", &keypad_clk),
+	DEF_LOOKUP("u300-gpio", &gpio_clk),
+	DEF_LOOKUP("rtc0", &rtc_clk),
+	DEF_LOOKUP("bustr", &bustr_clk),
+	DEF_LOOKUP("evhist", &evhist_clk),
+	DEF_LOOKUP("timer", &timer_clk),
+#ifdef CONFIG_MACH_U300_BS335
+	DEF_LOOKUP("ppm", &ppm_clk),
+#endif
+};
+
+static void __init clk_register(void)
+{
+	int i;
+
+	/* Register the lookups */
+	for (i = 0; i < ARRAY_SIZE(lookups); i++)
+		clkdev_add(&lookups[i]);
+}
+
+/*
+ * These are the clocks for cells registered as primecell drivers
+ * on the AMBA bus. These must be on during AMBA device registration
+ * since the bus probe will attempt to read magic configuration
+ * registers for these devices. If they are deactivated these probes
+ * will fail.
+ *
+ *
+ * Please note that on emif, both RAM and NAND is connected in dual
+ * RAM phones. On single RAM phones, ram is on semi and NAND on emif.
+ *
+ */
+void u300_clock_primecells(void)
+{
+	clk_enable(&intcon_clk);
+	clk_enable(&uart_clk);
+#ifdef CONFIG_MACH_U300_BS335
+	clk_enable(&uart1_clk);
+#endif
+	clk_enable(&spi_clk);
+
+	clk_enable(&mmcsd_clk);
+
+}
+EXPORT_SYMBOL(u300_clock_primecells);
+
+void u300_unclock_primecells(void)
+{
+
+	clk_disable(&intcon_clk);
+	clk_disable(&uart_clk);
+#ifdef CONFIG_MACH_U300_BS335
+	clk_disable(&uart1_clk);
+#endif
+	clk_disable(&spi_clk);
+	clk_disable(&mmcsd_clk);
+
+}
+EXPORT_SYMBOL(u300_unclock_primecells);
+
+/*
+ * The interrupt controller is enabled before the clock API is registered.
+ */
+void u300_enable_intcon_clock(void)
+{
+	clk_enable(&intcon_clk);
+}
+EXPORT_SYMBOL(u300_enable_intcon_clock);
+
+/*
+ * The timer is enabled before the clock API is registered.
+ */
+void u300_enable_timer_clock(void)
+{
+	clk_enable(&app_timer_clk);
+}
+EXPORT_SYMBOL(u300_enable_timer_clock);
+
+#if (defined(CONFIG_DEBUG_FS) && defined(CONFIG_U300_DEBUG))
+/*
+ * The following makes it possible to view the status (especially
+ * reference count and reset status) for the clocks in the platform
+ * by looking into the special file <debugfs>/u300_clocks
+ */
+
+/* A list of all clocks in the platform */
+static struct clk *clks[] = {
+	/* Top node clock for the AMBA bus */
+	&amba_clk,
+	/* Connected directly to the AMBA bus */
+	&cpu_clk,
+	&nandif_clk,
+	&semi_clk,
+#ifdef CONFIG_MACH_U300_BS335
+	&isp_clk,
+	&cds_clk,
+#endif
+	&dma_clk,
+	&aaif_clk,
+	&apex_clk,
+	&video_enc_clk,
+	&xgam_clk,
+	&ahb_clk,
+
+	/* AHB bridge clocks */
+	&ahb_subsys_clk,
+	&intcon_clk,
+	&mspro_clk,
+	&emif_clk,
+	/* FAST bridge clocks */
+	&fast_clk,
+	&mmcsd_clk,
+	&i2s0_clk,
+	&i2s1_clk,
+	&i2c0_clk,
+	&i2c1_clk,
+	&spi_clk,
+#ifdef CONFIG_MACH_U300_BS335
+	&uart1_clk,
+#endif
+	/* SLOW bridge clocks */
+	&slow_clk,
+	&wdog_clk,
+	&uart_clk,
+	&app_timer_clk,
+	&keypad_clk,
+	&gpio_clk,
+	&rtc_clk,
+	&bustr_clk,
+	&evhist_clk,
+	&timer_clk,
+#ifdef CONFIG_MACH_U300_BS335
+	&ppm_clk,
+#endif
+};
+
+static int u300_clocks_show(struct seq_file *s, void *data)
+{
+	struct clk *clk;
+	int i;
+
+	seq_printf(s, "CLOCK           DEVICE          RESET STATE\t" \
+		   "ACTIVE\tUSERS\tHW CTRL FREQ\n");
+	seq_printf(s, "---------------------------------------------" \
+		   "-----------------------------------------\n");
+	for (i = 0; i < ARRAY_SIZE(clks); i++) {
+		clk = clks[i];
+		if (clk != ERR_PTR(-ENOENT)) {
+			/* Format clock and device name nicely */
+			char cdp[33];
+			int chars;
+
+			chars = snprintf(&cdp[0], 17, "%s", clk->name);
+			while (chars < 16) {
+				cdp[chars] = ' ';
+				chars++;
+			}
+			chars = snprintf(&cdp[16], 17, "%s", clk->dev ?
+					 dev_name(clk->dev) : "N/A");
+			while (chars < 16) {
+				cdp[chars+16] = ' ';
+				chars++;
+			}
+			cdp[32] = '\0';
+			if (clk->get_rate)
+				seq_printf(s,
+					   "%s%s\t%s\t%d\t%s\t%lu Hz\n",
+					   &cdp[0],
+					   clk->reset ?
+					   "ASSERTED" : "RELEASED",
+					   clk->usecount ? "ON" : "OFF",
+					   clk->usecount,
+					   clk->hw_ctrld  ? "YES" : "NO ",
+					   clk->get_rate(clk));
+			else
+				seq_printf(s,
+					   "%s%s\t%s\t%d\t%s\t" \
+					   "(unknown rate)\n",
+					   &cdp[0],
+					   clk->reset ?
+					   "ASSERTED" : "RELEASED",
+					   clk->usecount ? "ON" : "OFF",
+					   clk->usecount,
+					   clk->hw_ctrld  ? "YES" : "NO ");
+		}
+	}
+	return 0;
+}
+
+static int u300_clocks_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, u300_clocks_show, NULL);
+}
+
+static const struct file_operations u300_clocks_operations = {
+	.open		= u300_clocks_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static void init_clk_read_procfs(void)
+{
+	/* Expose a simple debugfs interface to view all clocks */
+	(void) debugfs_create_file("u300_clocks", S_IFREG | S_IRUGO,
+				   NULL, NULL, &u300_clocks_operations);
+}
+#else
+static inline void init_clk_read_procfs(void)
+{
+}
+#endif
+
+static int __init u300_clock_init(void)
+{
+	u16 val;
+
+	/*
+	 * FIXME: shall all this powermanagement stuff really live here???
+	 */
+
+	/* Set system to run at PLL208, max performance, a known state. */
+	val = readw(U300_SYSCON_VBASE + U300_SYSCON_CCR);
+	val &= ~U300_SYSCON_CCR_CLKING_PERFORMANCE_MASK;
+	writew(val, U300_SYSCON_VBASE + U300_SYSCON_CCR);
+	/* Wait for the PLL208 to lock if not locked in yet */
+	while (!(readw(U300_SYSCON_VBASE + U300_SYSCON_CSR) &
+		 U300_SYSCON_CSR_PLL208_LOCK_IND));
+
+	/* Power management enable */
+	val = readw(U300_SYSCON_VBASE + U300_SYSCON_PMCR);
+	val |= U300_SYSCON_PMCR_PWR_MGNT_ENABLE;
+	writew(val, U300_SYSCON_VBASE + U300_SYSCON_PMCR);
+
+	clk_register();
+
+	init_clk_read_procfs();
+
+	/*
+	 * Some of these may be on when we boot the system so make sure they
+	 * are turned OFF.
+	 */
+	syscon_block_reset_enable(&timer_clk);
+	timer_clk.disable(&timer_clk);
+
+	/*
+	 * These shall be turned on by default when we boot the system
+	 * so make sure they are ON. (Adding CPU here is a bit too much.)
+	 * These clocks will be claimed by drivers later.
+	 */
+	syscon_block_reset_disable(&semi_clk);
+	syscon_block_reset_disable(&emif_clk);
+	semi_clk.enable(&semi_clk);
+	emif_clk.enable(&emif_clk);
+
+	return 0;
+}
+/* initialize clocking early to be available later in the boot */
+core_initcall(u300_clock_init);

arch/arm/mach-u300/clock.h

+/*
+ * arch/arm/mach-u300/include/mach/clock.h
+ *
+ * Copyright (C) 2004 - 2005 Nokia corporation
+ * Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
+ * Based on clocks.h by Tony Lindgren, Gordon McNutt and RidgeRun, Inc
+ * Copyright (C) 2007-2009 ST-Ericsson AB
+ * Adopted to ST-Ericsson U300 platforms by
+ * Jonas Aaberg <jonas.aberg@stericsson.com>
+ *
+ * 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.
+ *
+ */
+
+#ifndef __MACH_CLOCK_H
+#define __MACH_CLOCK_H
+
+#include <linux/clk.h>
+
+struct clk {
+	struct list_head node;
+	struct module *owner;
+	struct device *dev;
+	const char *name;
+	struct clk *parent;
+
+	spinlock_t lock;
+	unsigned long rate;
+	bool reset;
+	__u16 clk_val;
+	__s8 usecount;
+	__u32 res_reg;
+	__u16 res_mask;
+
+	bool hw_ctrld;
+
+	void (*recalc) (struct clk *);
+	int (*set_rate) (struct clk *, unsigned long);
+	unsigned long (*get_rate) (struct clk *);
+	unsigned long (*round_rate) (struct clk *, unsigned long);
+	void (*init) (struct clk *);
+	void (*enable) (struct clk *);
+	void (*disable) (struct clk *);
+};
+
+void u300_clock_primecells(void);
+void u300_unclock_primecells(void);
+void u300_enable_intcon_clock(void);
+void u300_enable_timer_clock(void);
+
+#endif

arch/arm/mach-u300/include/mach/clkdev.h

+#ifndef __MACH_CLKDEV_H
+#define __MACH_CLKDEV_H
+
+int __clk_get(struct clk *clk);
+void __clk_put(struct clk *clk);
+
+#endif