|  | /* | 
|  | *  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) || | 
|  | (read_cpuid_revision() < ARM_CPU_REV_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 ppcr) | 
|  | { | 
|  | struct sdram_params *sdram = &sdram_params; | 
|  | struct sdram_info sd; | 
|  | unsigned long flags; | 
|  | unsigned int unused; | 
|  |  | 
|  | sdram_calculate_timing(&sd, sa11x0_freq_table[ppcr].frequency, 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 | 
|  |  | 
|  | /* | 
|  | * 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(sa11x0_freq_table[ppcr].frequency, sdram); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int __init sa1110_cpu_init(struct cpufreq_policy *policy) | 
|  | { | 
|  | return cpufreq_generic_init(policy, sa11x0_freq_table, CPUFREQ_ETERNAL); | 
|  | } | 
|  |  | 
|  | /* 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 | CPUFREQ_NEED_INITIAL_FREQ_CHECK, | 
|  | .verify		= cpufreq_generic_frequency_table_verify, | 
|  | .target_index	= 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() || machine_is_h3600()) | 
|  | 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); |