cpufreq: sa11x0: move cpufreq driver to drivers/cpufreq

This patch moves cpufreq driver of ARM based sa11x0 platform to drivers/cpufreq.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

4 files changed, 661 insertions, 0 deletions

diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index 97f208daf8ae..09da6a3f0e8f 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -127,6 +127,12 @@ config ARM_S5PV210_CPUFREQ
 
 	  If in doubt, say N.
 
+config ARM_SA1100_CPUFREQ
+	bool
+
+config ARM_SA1110_CPUFREQ
+	bool
+
 config ARM_SPEAR_CPUFREQ
 	bool "SPEAr CPUFreq support"
 	depends on PLAT_SPEAR
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 8d5801645f9d..8b21016ac157 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -66,6 +66,8 @@ obj-$(CONFIG_PXA3xx)			+= pxa3xx-cpufreq.o
 obj-$(CONFIG_ARM_S3C2416_CPUFREQ)	+= s3c2416-cpufreq.o
 obj-$(CONFIG_ARM_S3C64XX_CPUFREQ)	+= s3c64xx-cpufreq.o
 obj-$(CONFIG_ARM_S5PV210_CPUFREQ)	+= s5pv210-cpufreq.o
+obj-$(CONFIG_ARM_SA1100_CPUFREQ)	+= sa1100-cpufreq.o
+obj-$(CONFIG_ARM_SA1110_CPUFREQ)	+= sa1110-cpufreq.o
 obj-$(CONFIG_ARM_SPEAR_CPUFREQ)		+= spear-cpufreq.o
 obj-$(CONFIG_ARCH_TEGRA)		+= tegra-cpufreq.o
 
diff --git a/drivers/cpufreq/sa1100-cpufreq.c b/drivers/cpufreq/sa1100-cpufreq.c
new file mode 100644
index 000000000000..cff18e87ca58
--- /dev/null
+++ b/drivers/cpufreq/sa1100-cpufreq.c
@@ -0,0 +1,247 @@
+/*
+ * cpu-sa1100.c: clock scaling for the SA1100
+ *
+ * Copyright (C) 2000 2001, The Delft University of Technology
+ *
+ * Authors:
+ * - Johan Pouwelse (J.A.Pouwelse@its.tudelft.nl): initial version
+ * - Erik Mouw (J.A.K.Mouw@its.tudelft.nl):
+ *   - major rewrite for linux-2.3.99
+ *   - rewritten for the more generic power management scheme in
+ *     linux-2.4.5-rmk1
+ *
+ * This software has been developed while working on the LART
+ * computing board (http://www.lartmaker.nl/), which is
+ * sponsored by the Mobile Multi-media Communications
+ * (http://www.mobimedia.org/) and Ubiquitous Communications
+ * (http://www.ubicom.tudelft.nl/) projects.
+ *
+ * The authors can be reached at:
+ *
+ *  Erik Mouw
+ *  Information and Communication Theory Group
+ *  Faculty of Information Technology and Systems
+ *  Delft University of Technology
+ *  P.O. Box 5031
+ *  2600 GA Delft
+ *  The Netherlands
+ *
+ *
+ * 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.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ *
+ * Theory of operations
+ * ====================
+ *
+ * Clock scaling can be used to lower the power consumption of the CPU
+ * core. This will give you a somewhat longer running time.
+ *
+ * The SA-1100 has a single register to change the core clock speed:
+ *
+ *   PPCR      0x90020014    PLL config
+ *
+ * However, the DRAM timings are closely related to the core clock
+ * speed, so we need to change these, too. The used registers are:
+ *
+ *   MDCNFG    0xA0000000    DRAM config
+ *   MDCAS0    0xA0000004    Access waveform
+ *   MDCAS1    0xA0000008    Access waveform
+ *   MDCAS2    0xA000000C    Access waveform
+ *
+ * Care must be taken to change the DRAM parameters the correct way,
+ * because otherwise the DRAM becomes unusable and the kernel will
+ * crash.
+ *
+ * The simple solution to avoid a kernel crash is to put the actual
+ * clock change in ROM and jump to that code from the kernel. The main
+ * disadvantage is that the ROM has to be modified, which is not
+ * possible on all SA-1100 platforms. Another disadvantage is that
+ * jumping to ROM makes clock switching unnecessary complicated.
+ *
+ * The idea behind this driver is that the memory configuration can be
+ * changed while running from DRAM (even with interrupts turned on!)
+ * as long as all re-configuration steps yield a valid DRAM
+ * configuration. The advantages are clear: it will run on all SA-1100
+ * platforms, and the code is very simple.
+ *
+ * If you really want to understand what is going on in
+ * sa1100_update_dram_timings(), you'll have to read sections 8.2,
+ * 9.5.7.3, and 10.2 from the "Intel StrongARM SA-1100 Microprocessor
+ * Developers Manual" (available for free from Intel).
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/cpufreq.h>
+#include <linux/io.h>
+
+#include <asm/cputype.h>
+
+#include <mach/generic.h>
+#include <mach/hardware.h>
+
+struct sa1100_dram_regs {
+	int speed;
+	u32 mdcnfg;
+	u32 mdcas0;
+	u32 mdcas1;
+	u32 mdcas2;
+};
+
+
+static struct cpufreq_driver sa1100_driver;
+
+static struct sa1100_dram_regs sa1100_dram_settings[] = {
+	/*speed,     mdcnfg,     mdcas0,     mdcas1,     mdcas2,   clock freq */
+	{ 59000, 0x00dc88a3, 0xcccccccf, 0xfffffffc, 0xffffffff},/*  59.0 MHz */
+	{ 73700, 0x011490a3, 0xcccccccf, 0xfffffffc, 0xffffffff},/*  73.7 MHz */
+	{ 88500, 0x014e90a3, 0xcccccccf, 0xfffffffc, 0xffffffff},/*  88.5 MHz */
+	{103200, 0x01889923, 0xcccccccf, 0xfffffffc, 0xffffffff},/* 103.2 MHz */
+	{118000, 0x01c29923, 0x9999998f, 0xfffffff9, 0xffffffff},/* 118.0 MHz */
+	{132700, 0x01fb2123, 0x9999998f, 0xfffffff9, 0xffffffff},/* 132.7 MHz */
+	{147500, 0x02352123, 0x3333330f, 0xfffffff3, 0xffffffff},/* 147.5 MHz */
+	{162200, 0x026b29a3, 0x38e38e1f, 0xfff8e38e, 0xffffffff},/* 162.2 MHz */
+	{176900, 0x02a329a3, 0x71c71c1f, 0xfff1c71c, 0xffffffff},/* 176.9 MHz */
+	{191700, 0x02dd31a3, 0xe38e383f, 0xffe38e38, 0xffffffff},/* 191.7 MHz */
+	{206400, 0x03153223, 0xc71c703f, 0xffc71c71, 0xffffffff},/* 206.4 MHz */
+	{221200, 0x034fba23, 0xc71c703f, 0xffc71c71, 0xffffffff},/* 221.2 MHz */
+	{235900, 0x03853a23, 0xe1e1e07f, 0xe1e1e1e1, 0xffffffe1},/* 235.9 MHz */
+	{250700, 0x03bf3aa3, 0xc3c3c07f, 0xc3c3c3c3, 0xffffffc3},/* 250.7 MHz */
+	{265400, 0x03f7c2a3, 0xc3c3c07f, 0xc3c3c3c3, 0xffffffc3},/* 265.4 MHz */
+	{280200, 0x0431c2a3, 0x878780ff, 0x87878787, 0xffffff87},/* 280.2 MHz */
+	{ 0, 0, 0, 0, 0 } /* last entry */
+};
+
+static void sa1100_update_dram_timings(int current_speed, int new_speed)
+{
+	struct sa1100_dram_regs *settings = sa1100_dram_settings;
+
+	/* find speed */
+	while (settings->speed != 0) {
+		if (new_speed == settings->speed)
+			break;
+
+		settings++;
+	}
+
+	if (settings->speed == 0) {
+		panic("%s: couldn't find dram setting for speed %d\n",
+		      __func__, new_speed);
+	}
+
+	/* No risk, no fun: run with interrupts on! */
+	if (new_speed > current_speed) {
+		/* We're going FASTER, so first relax the memory
+		 * timings before changing the core frequency
+		 */
+
+		/* Half the memory access clock */
+		MDCNFG |= MDCNFG_CDB2;
+
+		/* The order of these statements IS important, keep 8
+		 * pulses!!
+		 */
+		MDCAS2 = settings->mdcas2;
+		MDCAS1 = settings->mdcas1;
+		MDCAS0 = settings->mdcas0;
+		MDCNFG = settings->mdcnfg;
+	} else {
+		/* We're going SLOWER: first decrease the core
+		 * frequency and then tighten the memory settings.
+		 */
+
+		/* Half the memory access clock */
+		MDCNFG |= MDCNFG_CDB2;
+
+		/* The order of these statements IS important, keep 8
+		 * pulses!!
+		 */
+		MDCAS0 = settings->mdcas0;
+		MDCAS1 = settings->mdcas1;
+		MDCAS2 = settings->mdcas2;
+		MDCNFG = settings->mdcnfg;
+	}
+}
+
+static int sa1100_target(struct cpufreq_policy *policy,
+			 unsigned int target_freq,
+			 unsigned int relation)
+{
+	unsigned int cur = sa11x0_getspeed(0);
+	unsigned int new_ppcr;
+	struct cpufreq_freqs freqs;
+
+	new_ppcr = sa11x0_freq_to_ppcr(target_freq);
+	switch (relation) {
+	case CPUFREQ_RELATION_L:
+		if (sa11x0_ppcr_to_freq(new_ppcr) > policy->max)
+			new_ppcr--;
+		break;
+	case CPUFREQ_RELATION_H:
+		if ((sa11x0_ppcr_to_freq(new_ppcr) > target_freq) &&
+		    (sa11x0_ppcr_to_freq(new_ppcr - 1) >= policy->min))
+			new_ppcr--;
+		break;
+	}
+
+	freqs.old = cur;
+	freqs.new = sa11x0_ppcr_to_freq(new_ppcr);
+
+	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
+
+	if (freqs.new > cur)
+		sa1100_update_dram_timings(cur, freqs.new);
+
+	PPCR = new_ppcr;
+
+	if (freqs.new < cur)
+		sa1100_update_dram_timings(cur, freqs.new);
+
+	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
+
+	return 0;
+}
+
+static int __init sa1100_cpu_init(struct cpufreq_policy *policy)
+{
+	if (policy->cpu != 0)
+		return -EINVAL;
+	policy->cur = policy->min = policy->max = sa11x0_getspeed(0);
+	policy->cpuinfo.min_freq = 59000;
+	policy->cpuinfo.max_freq = 287000;
+	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
+	return 0;
+}
+
+static struct cpufreq_driver sa1100_driver __refdata = {
+	.flags		= CPUFREQ_STICKY,
+	.verify		= sa11x0_verify_speed,
+	.target		= sa1100_target,
+	.get		= sa11x0_getspeed,
+	.init		= sa1100_cpu_init,
+	.name		= "sa1100",
+};
+
+static int __init sa1100_dram_init(void)
+{
+	if (cpu_is_sa1100())
+		return cpufreq_register_driver(&sa1100_driver);
+	else
+		return -ENODEV;
+}
+
+arch_initcall(sa1100_dram_init);
diff --git a/drivers/cpufreq/sa1110-cpufreq.c b/drivers/cpufreq/sa1110-cpufreq.c
new file mode 100644
index 000000000000..39c90b6f4286
--- /dev/null
+++ b/drivers/cpufreq/sa1110-cpufreq.c
@@ -0,0 +1,406 @@
+/*
+ *  linux/arch/arm/mach-sa1100/cpu-sa1110.c
+ *
+ *  Copyright (C) 2001 Russell King
+ *
+ * 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.
+ *
+ * Note: there are two erratas that apply to the SA1110 here:
+ *  7 - SDRAM auto-power-up failure (rev A0)
+ * 13 - Corruption of internal register reads/writes following
+ *      SDRAM reads (rev A0, B0, B1)
+ *
+ * We ignore rev. A0 and B0 devices; I don't think they're worth supporting.
+ *
+ * The SDRAM type can be passed on the command line as cpu_sa1110.sdram=type
+ */
+#include <linux/cpufreq.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+
+#include <asm/cputype.h>
+#include <asm/mach-types.h>
+
+#include <mach/generic.h>
+#include <mach/hardware.h>
+
+#undef DEBUG
+
+struct sdram_params {
+	const char name[20];
+	u_char  rows;		/* bits				 */
+	u_char  cas_latency;	/* cycles			 */
+	u_char  tck;		/* clock cycle time (ns)	 */
+	u_char  trcd;		/* activate to r/w (ns)		 */
+	u_char  trp;		/* precharge to activate (ns)	 */
+	u_char  twr;		/* write recovery time (ns)	 */
+	u_short refresh;	/* refresh time for array (us)	 */
+};
+
+struct sdram_info {
+	u_int	mdcnfg;
+	u_int	mdrefr;
+	u_int	mdcas[3];
+};
+
+static struct sdram_params sdram_tbl[] __initdata = {
+	{	/* Toshiba TC59SM716 CL2 */
+		.name		= "TC59SM716-CL2",
+		.rows		= 12,
+		.tck		= 10,
+		.trcd		= 20,
+		.trp		= 20,
+		.twr		= 10,
+		.refresh	= 64000,
+		.cas_latency	= 2,
+	}, {	/* Toshiba TC59SM716 CL3 */
+		.name		= "TC59SM716-CL3",
+		.rows		= 12,
+		.tck		= 8,
+		.trcd		= 20,
+		.trp		= 20,
+		.twr		= 8,
+		.refresh	= 64000,
+		.cas_latency	= 3,
+	}, {	/* Samsung K4S641632D TC75 */
+		.name		= "K4S641632D",
+		.rows		= 14,
+		.tck		= 9,
+		.trcd		= 27,
+		.trp		= 20,
+		.twr		= 9,
+		.refresh	= 64000,
+		.cas_latency	= 3,
+	}, {	/* Samsung K4S281632B-1H */
+		.name           = "K4S281632B-1H",
+		.rows		= 12,
+		.tck		= 10,
+		.trp		= 20,
+		.twr		= 10,
+		.refresh	= 64000,
+		.cas_latency	= 3,
+	}, {	/* Samsung KM416S4030CT */
+		.name		= "KM416S4030CT",
+		.rows		= 13,
+		.tck		= 8,
+		.trcd		= 24,	/* 3 CLKs */
+		.trp		= 24,	/* 3 CLKs */
+		.twr		= 16,	/* Trdl: 2 CLKs */
+		.refresh	= 64000,
+		.cas_latency	= 3,
+	}, {	/* Winbond W982516AH75L CL3 */
+		.name		= "W982516AH75L",
+		.rows		= 16,
+		.tck		= 8,
+		.trcd		= 20,
+		.trp		= 20,
+		.twr		= 8,
+		.refresh	= 64000,
+		.cas_latency	= 3,
+	}, {	/* Micron MT48LC8M16A2TG-75 */
+		.name		= "MT48LC8M16A2TG-75",
+		.rows		= 12,
+		.tck		= 8,
+		.trcd		= 20,
+		.trp		= 20,
+		.twr		= 8,
+		.refresh	= 64000,
+		.cas_latency	= 3,
+	},
+};
+
+static struct sdram_params sdram_params;
+
+/*
+ * Given a period in ns and frequency in khz, calculate the number of
+ * cycles of frequency in period.  Note that we round up to the next
+ * cycle, even if we are only slightly over.
+ */
+static inline u_int ns_to_cycles(u_int ns, u_int khz)
+{
+	return (ns * khz + 999999) / 1000000;
+}
+
+/*
+ * Create the MDCAS register bit pattern.
+ */
+static inline void set_mdcas(u_int *mdcas, int delayed, u_int rcd)
+{
+	u_int shift;
+
+	rcd = 2 * rcd - 1;
+	shift = delayed + 1 + rcd;
+
+	mdcas[0]  = (1 << rcd) - 1;
+	mdcas[0] |= 0x55555555 << shift;
+	mdcas[1]  = mdcas[2] = 0x55555555 << (shift & 1);
+}
+
+static void
+sdram_calculate_timing(struct sdram_info *sd, u_int cpu_khz,
+		       struct sdram_params *sdram)
+{
+	u_int mem_khz, sd_khz, trp, twr;
+
+	mem_khz = cpu_khz / 2;
+	sd_khz = mem_khz;
+
+	/*
+	 * If SDCLK would invalidate the SDRAM timings,
+	 * run SDCLK at half speed.
+	 *
+	 * CPU steppings prior to B2 must either run the memory at
+	 * half speed or use delayed read latching (errata 13).
+	 */
+	if ((ns_to_cycles(sdram->tck, sd_khz) > 1) ||
+	    (CPU_REVISION < CPU_SA1110_B2 && sd_khz < 62000))
+		sd_khz /= 2;
+
+	sd->mdcnfg = MDCNFG & 0x007f007f;
+
+	twr = ns_to_cycles(sdram->twr, mem_khz);
+
+	/* trp should always be >1 */
+	trp = ns_to_cycles(sdram->trp, mem_khz) - 1;
+	if (trp < 1)
+		trp = 1;
+
+	sd->mdcnfg |= trp << 8;
+	sd->mdcnfg |= trp << 24;
+	sd->mdcnfg |= sdram->cas_latency << 12;
+	sd->mdcnfg |= sdram->cas_latency << 28;
+	sd->mdcnfg |= twr << 14;
+	sd->mdcnfg |= twr << 30;
+
+	sd->mdrefr = MDREFR & 0xffbffff0;
+	sd->mdrefr |= 7;
+
+	if (sd_khz != mem_khz)
+		sd->mdrefr |= MDREFR_K1DB2;
+
+	/* initial number of '1's in MDCAS + 1 */
+	set_mdcas(sd->mdcas, sd_khz >= 62000,
+		ns_to_cycles(sdram->trcd, mem_khz));
+
+#ifdef DEBUG
+	printk(KERN_DEBUG "MDCNFG: %08x MDREFR: %08x MDCAS0: %08x MDCAS1: %08x MDCAS2: %08x\n",
+		sd->mdcnfg, sd->mdrefr, sd->mdcas[0], sd->mdcas[1],
+		sd->mdcas[2]);
+#endif
+}
+
+/*
+ * Set the SDRAM refresh rate.
+ */
+static inline void sdram_set_refresh(u_int dri)
+{
+	MDREFR = (MDREFR & 0xffff000f) | (dri << 4);
+	(void) MDREFR;
+}
+
+/*
+ * Update the refresh period.  We do this such that we always refresh
+ * the SDRAMs within their permissible period.  The refresh period is
+ * always a multiple of the memory clock (fixed at cpu_clock / 2).
+ *
+ * FIXME: we don't currently take account of burst accesses here,
+ * but neither do Intels DM nor Angel.
+ */
+static void
+sdram_update_refresh(u_int cpu_khz, struct sdram_params *sdram)
+{
+	u_int ns_row = (sdram->refresh * 1000) >> sdram->rows;
+	u_int dri = ns_to_cycles(ns_row, cpu_khz / 2) / 32;
+
+#ifdef DEBUG
+	mdelay(250);
+	printk(KERN_DEBUG "new dri value = %d\n", dri);
+#endif
+
+	sdram_set_refresh(dri);
+}
+
+/*
+ * Ok, set the CPU frequency.
+ */
+static int sa1110_target(struct cpufreq_policy *policy,
+			 unsigned int target_freq,
+			 unsigned int relation)
+{
+	struct sdram_params *sdram = &sdram_params;
+	struct cpufreq_freqs freqs;
+	struct sdram_info sd;
+	unsigned long flags;
+	unsigned int ppcr, unused;
+
+	switch (relation) {
+	case CPUFREQ_RELATION_L:
+		ppcr = sa11x0_freq_to_ppcr(target_freq);
+		if (sa11x0_ppcr_to_freq(ppcr) > policy->max)
+			ppcr--;
+		break;
+	case CPUFREQ_RELATION_H:
+		ppcr = sa11x0_freq_to_ppcr(target_freq);
+		if (ppcr && (sa11x0_ppcr_to_freq(ppcr) > target_freq) &&
+		    (sa11x0_ppcr_to_freq(ppcr-1) >= policy->min))
+			ppcr--;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	freqs.old = sa11x0_getspeed(0);
+	freqs.new = sa11x0_ppcr_to_freq(ppcr);
+
+	sdram_calculate_timing(&sd, freqs.new, sdram);
+
+#if 0
+	/*
+	 * These values are wrong according to the SA1110 documentation
+	 * and errata, but they seem to work.  Need to get a storage
+	 * scope on to the SDRAM signals to work out why.
+	 */
+	if (policy->max < 147500) {
+		sd.mdrefr |= MDREFR_K1DB2;
+		sd.mdcas[0] = 0xaaaaaa7f;
+	} else {
+		sd.mdrefr &= ~MDREFR_K1DB2;
+		sd.mdcas[0] = 0xaaaaaa9f;
+	}
+	sd.mdcas[1] = 0xaaaaaaaa;
+	sd.mdcas[2] = 0xaaaaaaaa;
+#endif
+
+	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
+
+	/*
+	 * The clock could be going away for some time.  Set the SDRAMs
+	 * to refresh rapidly (every 64 memory clock cycles).  To get
+	 * through the whole array, we need to wait 262144 mclk cycles.
+	 * We wait 20ms to be safe.
+	 */
+	sdram_set_refresh(2);
+	if (!irqs_disabled())
+		msleep(20);
+	else
+		mdelay(20);
+
+	/*
+	 * Reprogram the DRAM timings with interrupts disabled, and
+	 * ensure that we are doing this within a complete cache line.
+	 * This means that we won't access SDRAM for the duration of
+	 * the programming.
+	 */
+	local_irq_save(flags);
+	asm("mcr p15, 0, %0, c7, c10, 4" : : "r" (0));
+	udelay(10);
+	__asm__ __volatile__("\n\
+		b	2f					\n\
+		.align	5					\n\
+1:		str	%3, [%1, #0]		@ MDCNFG	\n\
+		str	%4, [%1, #28]		@ MDREFR	\n\
+		str	%5, [%1, #4]		@ MDCAS0	\n\
+		str	%6, [%1, #8]		@ MDCAS1	\n\
+		str	%7, [%1, #12]		@ MDCAS2	\n\
+		str	%8, [%2, #0]		@ PPCR		\n\
+		ldr	%0, [%1, #0]				\n\
+		b	3f					\n\
+2:		b	1b					\n\
+3:		nop						\n\
+		nop"
+		: "=&r" (unused)
+		: "r" (&MDCNFG), "r" (&PPCR), "0" (sd.mdcnfg),
+		  "r" (sd.mdrefr), "r" (sd.mdcas[0]),
+		  "r" (sd.mdcas[1]), "r" (sd.mdcas[2]), "r" (ppcr));
+	local_irq_restore(flags);
+
+	/*
+	 * Now, return the SDRAM refresh back to normal.
+	 */
+	sdram_update_refresh(freqs.new, sdram);
+
+	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
+
+	return 0;
+}
+
+static int __init sa1110_cpu_init(struct cpufreq_policy *policy)
+{
+	if (policy->cpu != 0)
+		return -EINVAL;
+	policy->cur = policy->min = policy->max = sa11x0_getspeed(0);
+	policy->cpuinfo.min_freq = 59000;
+	policy->cpuinfo.max_freq = 287000;
+	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
+	return 0;
+}
+
+/* sa1110_driver needs __refdata because it must remain after init registers
+ * it with cpufreq_register_driver() */
+static struct cpufreq_driver sa1110_driver __refdata = {
+	.flags		= CPUFREQ_STICKY,
+	.verify		= sa11x0_verify_speed,
+	.target		= sa1110_target,
+	.get		= sa11x0_getspeed,
+	.init		= sa1110_cpu_init,
+	.name		= "sa1110",
+};
+
+static struct sdram_params *sa1110_find_sdram(const char *name)
+{
+	struct sdram_params *sdram;
+
+	for (sdram = sdram_tbl; sdram < sdram_tbl + ARRAY_SIZE(sdram_tbl);
+	     sdram++)
+		if (strcmp(name, sdram->name) == 0)
+			return sdram;
+
+	return NULL;
+}
+
+static char sdram_name[16];
+
+static int __init sa1110_clk_init(void)
+{
+	struct sdram_params *sdram;
+	const char *name = sdram_name;
+
+	if (!cpu_is_sa1110())
+		return -ENODEV;
+
+	if (!name[0]) {
+		if (machine_is_assabet())
+			name = "TC59SM716-CL3";
+		if (machine_is_pt_system3())
+			name = "K4S641632D";
+		if (machine_is_h3100())
+			name = "KM416S4030CT";
+		if (machine_is_jornada720())
+			name = "K4S281632B-1H";
+		if (machine_is_nanoengine())
+			name = "MT48LC8M16A2TG-75";
+	}
+
+	sdram = sa1110_find_sdram(name);
+	if (sdram) {
+		printk(KERN_DEBUG "SDRAM: tck: %d trcd: %d trp: %d"
+			" twr: %d refresh: %d cas_latency: %d\n",
+			sdram->tck, sdram->trcd, sdram->trp,
+			sdram->twr, sdram->refresh, sdram->cas_latency);
+
+		memcpy(&sdram_params, sdram, sizeof(sdram_params));
+
+		return cpufreq_register_driver(&sa1110_driver);
+	}
+
+	return 0;
+}
+
+module_param_string(sdram, sdram_name, sizeof(sdram_name), 0);
+arch_initcall(sa1110_clk_init);