arch/arm/mach-sa1100/cpu-sa1110.c - maze/linux - Git at Google

 /*
  *  linux/arch/arm/mach-sa1100/cpu-sa1110.c
  *
  *  Copyright (C) 2001 Russell King
  *
  *  $Id: cpu-sa1110.c,v 1.9 2002/07/06 16:53:18 rmk Exp $
  *
  * 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.
  */
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
 #include <linux/cpufreq.h>
 #include <linux/delay.h>
 #include <linux/init.h>

 #include <asm/hardware.h>
 #include <asm/mach-types.h>
 #include <asm/io.h>
 #include <asm/system.h>

 #include "generic.h"

 #undef DEBUG

 static struct cpufreq_driver sa1110_driver;

 struct sdram_params {
 	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 tc59sm716_cl2_params __initdata = {
 	.rows			= 12,
 	.tck			= 10,
 	.trcd			= 20,
 	.trp			= 20,
 	.twr			= 10,
 	.refresh		= 64000,
 	.cas_latency		= 2,
 };

 static struct sdram_params tc59sm716_cl3_params __initdata = {
 	.rows			= 12,
 	.tck			= 8,
 	.trcd			= 20,
 	.trp			= 20,
 	.twr			= 8,
 	.refresh		= 64000,
 	.cas_latency		= 3,
 };

 static struct sdram_params samsung_k4s641632d_tc75 __initdata = {
 	.rows			= 14,
 	.tck			= 9,
 	.trcd			= 27,
 	.trp			= 20,
 	.twr			= 9,
 	.refresh		= 64000,
 	.cas_latency		= 3,
 };

 static struct sdram_params samsung_km416s4030ct __initdata = {
 	.rows			= 13,
 	.tck			= 8,
 	.trcd			= 24,	/* 3 CLKs */
 	.trp			= 24,	/* 3 CLKs */
 	.twr			= 16,	/* Trdl: 2 CLKs */
 	.refresh		= 64000,
 	.cas_latency		= 3,
 };

 static struct sdram_params wbond_w982516ah75l_cl3_params __initdata = {
 	.rows			= 16,
 	.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("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("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);
 	freqs.cpu = 0;

 	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(&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(&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->governor = CPUFREQ_DEFAULT_GOVERNOR;
 	policy->cpuinfo.min_freq = 59000;
 	policy->cpuinfo.max_freq = 287000;
 	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
 	return 0;
 }

 static struct cpufreq_driver sa1110_driver = {
 	.flags		= CPUFREQ_STICKY,
 	.verify		= sa11x0_verify_speed,
 	.target		= sa1110_target,
 	.get		= sa11x0_getspeed,
 	.init		= sa1110_cpu_init,
 	.name		= "sa1110",
 };

 static int __init sa1110_clk_init(void)
 {
 	struct sdram_params *sdram = NULL;

 	if (machine_is_assabet())
 		sdram = &tc59sm716_cl3_params;

 	if (machine_is_pt_system3())
 		sdram = &samsung_k4s641632d_tc75;

 	if (machine_is_h3100())
 		sdram = &samsung_km416s4030ct;

 	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;
 }

 arch_initcall(sa1110_clk_init);
	/*
	* linux/arch/arm/mach-sa1100/cpu-sa1110.c
	*
	* Copyright (C) 2001 Russell King
	*
	* $Id: cpu-sa1110.c,v 1.9 2002/07/06 16:53:18 rmk Exp $
	*
	* 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.
	*/
	#include <linux/types.h>
	#include <linux/kernel.h>
	#include <linux/sched.h>
	#include <linux/cpufreq.h>
	#include <linux/delay.h>
	#include <linux/init.h>

	#include <asm/hardware.h>
	#include <asm/mach-types.h>
	#include <asm/io.h>
	#include <asm/system.h>

	#include "generic.h"

	#undef DEBUG

	static struct cpufreq_driver sa1110_driver;

	struct sdram_params {
	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 tc59sm716_cl2_params __initdata = {
	.rows = 12,
	.tck = 10,
	.trcd = 20,
	.trp = 20,
	.twr = 10,
	.refresh = 64000,
	.cas_latency = 2,
	};

	static struct sdram_params tc59sm716_cl3_params __initdata = {
	.rows = 12,
	.tck = 8,
	.trcd = 20,
	.trp = 20,
	.twr = 8,
	.refresh = 64000,
	.cas_latency = 3,
	};

	static struct sdram_params samsung_k4s641632d_tc75 __initdata = {
	.rows = 14,
	.tck = 9,
	.trcd = 27,
	.trp = 20,
	.twr = 9,
	.refresh = 64000,
	.cas_latency = 3,
	};

	static struct sdram_params samsung_km416s4030ct __initdata = {
	.rows = 13,
	.tck = 8,
	.trcd = 24, /* 3 CLKs */
	.trp = 24, /* 3 CLKs */
	.twr = 16, /* Trdl: 2 CLKs */
	.refresh = 64000,
	.cas_latency = 3,
	};

	static struct sdram_params wbond_w982516ah75l_cl3_params __initdata = {
	.rows = 16,
	.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("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("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);
	freqs.cpu = 0;

	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(&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(&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->governor = CPUFREQ_DEFAULT_GOVERNOR;
	policy->cpuinfo.min_freq = 59000;
	policy->cpuinfo.max_freq = 287000;
	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
	return 0;
	}

	static struct cpufreq_driver sa1110_driver = {
	.flags = CPUFREQ_STICKY,
	.verify = sa11x0_verify_speed,
	.target = sa1110_target,
	.get = sa11x0_getspeed,
	.init = sa1110_cpu_init,
	.name = "sa1110",
	};

	static int __init sa1110_clk_init(void)
	{
	struct sdram_params *sdram = NULL;

	if (machine_is_assabet())
	sdram = &tc59sm716_cl3_params;

	if (machine_is_pt_system3())
	sdram = &samsung_k4s641632d_tc75;

	if (machine_is_h3100())
	sdram = &samsung_km416s4030ct;

	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;
	}

	arch_initcall(sa1110_clk_init);