| /* |
| * linux/arch/arm/mach-pxa/cpufreq-pxa2xx.c |
| * |
| * Copyright (C) 2002,2003 Intrinsyc Software |
| * |
| * 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 |
| * |
| * History: |
| * 31-Jul-2002 : Initial version [FB] |
| * 29-Jan-2003 : added PXA255 support [FB] |
| * 20-Apr-2003 : ported to v2.5 (Dustin McIntire, Sensoria Corp.) |
| * |
| * Note: |
| * This driver may change the memory bus clock rate, but will not do any |
| * platform specific access timing changes... for example if you have flash |
| * memory connected to CS0, you will need to register a platform specific |
| * notifier which will adjust the memory access strobes to maintain a |
| * minimum strobe width. |
| * |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/sched.h> |
| #include <linux/init.h> |
| #include <linux/cpufreq.h> |
| |
| #include <mach/hardware.h> |
| #include <mach/pxa-regs.h> |
| #include <mach/pxa2xx-regs.h> |
| |
| #ifdef DEBUG |
| static unsigned int freq_debug; |
| module_param(freq_debug, uint, 0); |
| MODULE_PARM_DESC(freq_debug, "Set the debug messages to on=1/off=0"); |
| #else |
| #define freq_debug 0 |
| #endif |
| |
| static unsigned int pxa27x_maxfreq; |
| module_param(pxa27x_maxfreq, uint, 0); |
| MODULE_PARM_DESC(pxa27x_maxfreq, "Set the pxa27x maxfreq in MHz" |
| "(typically 624=>pxa270, 416=>pxa271, 520=>pxa272)"); |
| |
| typedef struct { |
| unsigned int khz; |
| unsigned int membus; |
| unsigned int cccr; |
| unsigned int div2; |
| unsigned int cclkcfg; |
| } pxa_freqs_t; |
| |
| /* Define the refresh period in mSec for the SDRAM and the number of rows */ |
| #define SDRAM_TREF 64 /* standard 64ms SDRAM */ |
| static unsigned int sdram_rows; |
| |
| #define CCLKCFG_TURBO 0x1 |
| #define CCLKCFG_FCS 0x2 |
| #define CCLKCFG_HALFTURBO 0x4 |
| #define CCLKCFG_FASTBUS 0x8 |
| #define MDREFR_DB2_MASK (MDREFR_K2DB2 | MDREFR_K1DB2) |
| #define MDREFR_DRI_MASK 0xFFF |
| |
| #define MDCNFG_DRAC2(mdcnfg) (((mdcnfg) >> 21) & 0x3) |
| #define MDCNFG_DRAC0(mdcnfg) (((mdcnfg) >> 5) & 0x3) |
| |
| /* |
| * PXA255 definitions |
| */ |
| /* Use the run mode frequencies for the CPUFREQ_POLICY_PERFORMANCE policy */ |
| #define CCLKCFG CCLKCFG_TURBO | CCLKCFG_FCS |
| |
| static pxa_freqs_t pxa255_run_freqs[] = |
| { |
| /* CPU MEMBUS CCCR DIV2 CCLKCFG run turbo PXbus SDRAM */ |
| { 99500, 99500, 0x121, 1, CCLKCFG}, /* 99, 99, 50, 50 */ |
| {132700, 132700, 0x123, 1, CCLKCFG}, /* 133, 133, 66, 66 */ |
| {199100, 99500, 0x141, 0, CCLKCFG}, /* 199, 199, 99, 99 */ |
| {265400, 132700, 0x143, 1, CCLKCFG}, /* 265, 265, 133, 66 */ |
| {331800, 165900, 0x145, 1, CCLKCFG}, /* 331, 331, 166, 83 */ |
| {398100, 99500, 0x161, 0, CCLKCFG}, /* 398, 398, 196, 99 */ |
| }; |
| |
| /* Use the turbo mode frequencies for the CPUFREQ_POLICY_POWERSAVE policy */ |
| static pxa_freqs_t pxa255_turbo_freqs[] = |
| { |
| /* CPU MEMBUS CCCR DIV2 CCLKCFG run turbo PXbus SDRAM */ |
| { 99500, 99500, 0x121, 1, CCLKCFG}, /* 99, 99, 50, 50 */ |
| {199100, 99500, 0x221, 0, CCLKCFG}, /* 99, 199, 50, 99 */ |
| {298500, 99500, 0x321, 0, CCLKCFG}, /* 99, 287, 50, 99 */ |
| {298600, 99500, 0x1c1, 0, CCLKCFG}, /* 199, 287, 99, 99 */ |
| {398100, 99500, 0x241, 0, CCLKCFG}, /* 199, 398, 99, 99 */ |
| }; |
| |
| #define NUM_PXA25x_RUN_FREQS ARRAY_SIZE(pxa255_run_freqs) |
| #define NUM_PXA25x_TURBO_FREQS ARRAY_SIZE(pxa255_turbo_freqs) |
| |
| static struct cpufreq_frequency_table |
| pxa255_run_freq_table[NUM_PXA25x_RUN_FREQS+1]; |
| static struct cpufreq_frequency_table |
| pxa255_turbo_freq_table[NUM_PXA25x_TURBO_FREQS+1]; |
| |
| static unsigned int pxa255_turbo_table; |
| module_param(pxa255_turbo_table, uint, 0); |
| MODULE_PARM_DESC(pxa255_turbo_table, "Selects the frequency table (0 = run table, !0 = turbo table)"); |
| |
| /* |
| * PXA270 definitions |
| * |
| * For the PXA27x: |
| * Control variables are A, L, 2N for CCCR; B, HT, T for CLKCFG. |
| * |
| * A = 0 => memory controller clock from table 3-7, |
| * A = 1 => memory controller clock = system bus clock |
| * Run mode frequency = 13 MHz * L |
| * Turbo mode frequency = 13 MHz * L * N |
| * System bus frequency = 13 MHz * L / (B + 1) |
| * |
| * In CCCR: |
| * A = 1 |
| * L = 16 oscillator to run mode ratio |
| * 2N = 6 2 * (turbo mode to run mode ratio) |
| * |
| * In CCLKCFG: |
| * B = 1 Fast bus mode |
| * HT = 0 Half-Turbo mode |
| * T = 1 Turbo mode |
| * |
| * For now, just support some of the combinations in table 3-7 of |
| * PXA27x Processor Family Developer's Manual to simplify frequency |
| * change sequences. |
| */ |
| #define PXA27x_CCCR(A, L, N2) (A << 25 | N2 << 7 | L) |
| #define CCLKCFG2(B, HT, T) \ |
| (CCLKCFG_FCS | \ |
| ((B) ? CCLKCFG_FASTBUS : 0) | \ |
| ((HT) ? CCLKCFG_HALFTURBO : 0) | \ |
| ((T) ? CCLKCFG_TURBO : 0)) |
| |
| static pxa_freqs_t pxa27x_freqs[] = { |
| {104000, 104000, PXA27x_CCCR(1, 8, 2), 0, CCLKCFG2(1, 0, 1)}, |
| {156000, 104000, PXA27x_CCCR(1, 8, 6), 0, CCLKCFG2(1, 1, 1)}, |
| {208000, 208000, PXA27x_CCCR(0, 16, 2), 1, CCLKCFG2(0, 0, 1)}, |
| {312000, 208000, PXA27x_CCCR(1, 16, 3), 1, CCLKCFG2(1, 0, 1)}, |
| {416000, 208000, PXA27x_CCCR(1, 16, 4), 1, CCLKCFG2(1, 0, 1)}, |
| {520000, 208000, PXA27x_CCCR(1, 16, 5), 1, CCLKCFG2(1, 0, 1)}, |
| {624000, 208000, PXA27x_CCCR(1, 16, 6), 1, CCLKCFG2(1, 0, 1)} |
| }; |
| |
| #define NUM_PXA27x_FREQS ARRAY_SIZE(pxa27x_freqs) |
| static struct cpufreq_frequency_table |
| pxa27x_freq_table[NUM_PXA27x_FREQS+1]; |
| |
| extern unsigned get_clk_frequency_khz(int info); |
| |
| static void find_freq_tables(struct cpufreq_frequency_table **freq_table, |
| pxa_freqs_t **pxa_freqs) |
| { |
| if (cpu_is_pxa25x()) { |
| if (!pxa255_turbo_table) { |
| *pxa_freqs = pxa255_run_freqs; |
| *freq_table = pxa255_run_freq_table; |
| } else { |
| *pxa_freqs = pxa255_turbo_freqs; |
| *freq_table = pxa255_turbo_freq_table; |
| } |
| } |
| if (cpu_is_pxa27x()) { |
| *pxa_freqs = pxa27x_freqs; |
| *freq_table = pxa27x_freq_table; |
| } |
| } |
| |
| static void pxa27x_guess_max_freq(void) |
| { |
| if (!pxa27x_maxfreq) { |
| pxa27x_maxfreq = 416000; |
| printk(KERN_INFO "PXA CPU 27x max frequency not defined " |
| "(pxa27x_maxfreq), assuming pxa271 with %dkHz maxfreq\n", |
| pxa27x_maxfreq); |
| } else { |
| pxa27x_maxfreq *= 1000; |
| } |
| } |
| |
| static void init_sdram_rows(void) |
| { |
| uint32_t mdcnfg = MDCNFG; |
| unsigned int drac2 = 0, drac0 = 0; |
| |
| if (mdcnfg & (MDCNFG_DE2 | MDCNFG_DE3)) |
| drac2 = MDCNFG_DRAC2(mdcnfg); |
| |
| if (mdcnfg & (MDCNFG_DE0 | MDCNFG_DE1)) |
| drac0 = MDCNFG_DRAC0(mdcnfg); |
| |
| sdram_rows = 1 << (11 + max(drac0, drac2)); |
| } |
| |
| static u32 mdrefr_dri(unsigned int freq) |
| { |
| u32 dri = 0; |
| |
| if (cpu_is_pxa25x()) |
| dri = ((freq * SDRAM_TREF) / (sdram_rows * 32)); |
| if (cpu_is_pxa27x()) |
| dri = ((freq * SDRAM_TREF) / (sdram_rows - 31)) / 32; |
| return dri; |
| } |
| |
| /* find a valid frequency point */ |
| static int pxa_verify_policy(struct cpufreq_policy *policy) |
| { |
| struct cpufreq_frequency_table *pxa_freqs_table; |
| pxa_freqs_t *pxa_freqs; |
| int ret; |
| |
| find_freq_tables(&pxa_freqs_table, &pxa_freqs); |
| ret = cpufreq_frequency_table_verify(policy, pxa_freqs_table); |
| |
| if (freq_debug) |
| pr_debug("Verified CPU policy: %dKhz min to %dKhz max\n", |
| policy->min, policy->max); |
| |
| return ret; |
| } |
| |
| static unsigned int pxa_cpufreq_get(unsigned int cpu) |
| { |
| return get_clk_frequency_khz(0); |
| } |
| |
| static int pxa_set_target(struct cpufreq_policy *policy, |
| unsigned int target_freq, |
| unsigned int relation) |
| { |
| struct cpufreq_frequency_table *pxa_freqs_table; |
| pxa_freqs_t *pxa_freq_settings; |
| struct cpufreq_freqs freqs; |
| unsigned int idx; |
| unsigned long flags; |
| unsigned int new_freq_cpu, new_freq_mem; |
| unsigned int unused, preset_mdrefr, postset_mdrefr, cclkcfg; |
| |
| /* Get the current policy */ |
| find_freq_tables(&pxa_freqs_table, &pxa_freq_settings); |
| |
| /* Lookup the next frequency */ |
| if (cpufreq_frequency_table_target(policy, pxa_freqs_table, |
| target_freq, relation, &idx)) { |
| return -EINVAL; |
| } |
| |
| new_freq_cpu = pxa_freq_settings[idx].khz; |
| new_freq_mem = pxa_freq_settings[idx].membus; |
| freqs.old = policy->cur; |
| freqs.new = new_freq_cpu; |
| freqs.cpu = policy->cpu; |
| |
| if (freq_debug) |
| pr_debug(KERN_INFO "Changing CPU frequency to %d Mhz, " |
| "(SDRAM %d Mhz)\n", |
| freqs.new / 1000, (pxa_freq_settings[idx].div2) ? |
| (new_freq_mem / 2000) : (new_freq_mem / 1000)); |
| |
| /* |
| * Tell everyone what we're about to do... |
| * you should add a notify client with any platform specific |
| * Vcc changing capability |
| */ |
| cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); |
| |
| /* Calculate the next MDREFR. If we're slowing down the SDRAM clock |
| * we need to preset the smaller DRI before the change. If we're |
| * speeding up we need to set the larger DRI value after the change. |
| */ |
| preset_mdrefr = postset_mdrefr = MDREFR; |
| if ((MDREFR & MDREFR_DRI_MASK) > mdrefr_dri(new_freq_mem)) { |
| preset_mdrefr = (preset_mdrefr & ~MDREFR_DRI_MASK); |
| preset_mdrefr |= mdrefr_dri(new_freq_mem); |
| } |
| postset_mdrefr = |
| (postset_mdrefr & ~MDREFR_DRI_MASK) | mdrefr_dri(new_freq_mem); |
| |
| /* If we're dividing the memory clock by two for the SDRAM clock, this |
| * must be set prior to the change. Clearing the divide must be done |
| * after the change. |
| */ |
| if (pxa_freq_settings[idx].div2) { |
| preset_mdrefr |= MDREFR_DB2_MASK; |
| postset_mdrefr |= MDREFR_DB2_MASK; |
| } else { |
| postset_mdrefr &= ~MDREFR_DB2_MASK; |
| } |
| |
| local_irq_save(flags); |
| |
| /* Set new the CCCR and prepare CCLKCFG */ |
| CCCR = pxa_freq_settings[idx].cccr; |
| cclkcfg = pxa_freq_settings[idx].cclkcfg; |
| |
| asm volatile(" \n\ |
| ldr r4, [%1] /* load MDREFR */ \n\ |
| b 2f \n\ |
| .align 5 \n\ |
| 1: \n\ |
| str %3, [%1] /* preset the MDREFR */ \n\ |
| mcr p14, 0, %2, c6, c0, 0 /* set CCLKCFG[FCS] */ \n\ |
| str %4, [%1] /* postset the MDREFR */ \n\ |
| \n\ |
| b 3f \n\ |
| 2: b 1b \n\ |
| 3: nop \n\ |
| " |
| : "=&r" (unused) |
| : "r" (&MDREFR), "r" (cclkcfg), |
| "r" (preset_mdrefr), "r" (postset_mdrefr) |
| : "r4", "r5"); |
| local_irq_restore(flags); |
| |
| /* |
| * Tell everyone what we've just done... |
| * you should add a notify client with any platform specific |
| * SDRAM refresh timer adjustments |
| */ |
| cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); |
| |
| return 0; |
| } |
| |
| static __init int pxa_cpufreq_init(struct cpufreq_policy *policy) |
| { |
| int i; |
| unsigned int freq; |
| struct cpufreq_frequency_table *pxa255_freq_table; |
| pxa_freqs_t *pxa255_freqs; |
| |
| /* try to guess pxa27x cpu */ |
| if (cpu_is_pxa27x()) |
| pxa27x_guess_max_freq(); |
| |
| init_sdram_rows(); |
| |
| /* set default policy and cpuinfo */ |
| policy->cpuinfo.transition_latency = 1000; /* FIXME: 1 ms, assumed */ |
| policy->cur = get_clk_frequency_khz(0); /* current freq */ |
| policy->min = policy->max = policy->cur; |
| |
| /* Generate pxa25x the run cpufreq_frequency_table struct */ |
| for (i = 0; i < NUM_PXA25x_RUN_FREQS; i++) { |
| pxa255_run_freq_table[i].frequency = pxa255_run_freqs[i].khz; |
| pxa255_run_freq_table[i].index = i; |
| } |
| pxa255_run_freq_table[i].frequency = CPUFREQ_TABLE_END; |
| |
| /* Generate pxa25x the turbo cpufreq_frequency_table struct */ |
| for (i = 0; i < NUM_PXA25x_TURBO_FREQS; i++) { |
| pxa255_turbo_freq_table[i].frequency = |
| pxa255_turbo_freqs[i].khz; |
| pxa255_turbo_freq_table[i].index = i; |
| } |
| pxa255_turbo_freq_table[i].frequency = CPUFREQ_TABLE_END; |
| |
| pxa255_turbo_table = !!pxa255_turbo_table; |
| |
| /* Generate the pxa27x cpufreq_frequency_table struct */ |
| for (i = 0; i < NUM_PXA27x_FREQS; i++) { |
| freq = pxa27x_freqs[i].khz; |
| if (freq > pxa27x_maxfreq) |
| break; |
| pxa27x_freq_table[i].frequency = freq; |
| pxa27x_freq_table[i].index = i; |
| } |
| pxa27x_freq_table[i].frequency = CPUFREQ_TABLE_END; |
| |
| /* |
| * Set the policy's minimum and maximum frequencies from the tables |
| * just constructed. This sets cpuinfo.mxx_freq, min and max. |
| */ |
| if (cpu_is_pxa25x()) { |
| find_freq_tables(&pxa255_freq_table, &pxa255_freqs); |
| pr_info("PXA255 cpufreq using %s frequency table\n", |
| pxa255_turbo_table ? "turbo" : "run"); |
| cpufreq_frequency_table_cpuinfo(policy, pxa255_freq_table); |
| } |
| else if (cpu_is_pxa27x()) |
| cpufreq_frequency_table_cpuinfo(policy, pxa27x_freq_table); |
| |
| printk(KERN_INFO "PXA CPU frequency change support initialized\n"); |
| |
| return 0; |
| } |
| |
| static struct cpufreq_driver pxa_cpufreq_driver = { |
| .verify = pxa_verify_policy, |
| .target = pxa_set_target, |
| .init = pxa_cpufreq_init, |
| .get = pxa_cpufreq_get, |
| .name = "PXA2xx", |
| }; |
| |
| static int __init pxa_cpu_init(void) |
| { |
| int ret = -ENODEV; |
| if (cpu_is_pxa25x() || cpu_is_pxa27x()) |
| ret = cpufreq_register_driver(&pxa_cpufreq_driver); |
| return ret; |
| } |
| |
| static void __exit pxa_cpu_exit(void) |
| { |
| cpufreq_unregister_driver(&pxa_cpufreq_driver); |
| } |
| |
| |
| MODULE_AUTHOR("Intrinsyc Software Inc."); |
| MODULE_DESCRIPTION("CPU frequency changing driver for the PXA architecture"); |
| MODULE_LICENSE("GPL"); |
| module_init(pxa_cpu_init); |
| module_exit(pxa_cpu_exit); |