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+/*
+ * 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 <linux/err.h>
+#include <linux/regulator/consumer.h>
+#include <linux/io.h>
+
+#include <mach/pxa2xx-regs.h>
+#include <mach/smemc.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 struct regulator *vcc_core;
+
+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;
+ int vmin;
+ int vmax;
+} 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, -1, -1}, /* 99, 99, 50, 50 */
+ {132700, 132700, 0x123, 1, CCLKCFG, -1, -1}, /* 133, 133, 66, 66 */
+ {199100, 99500, 0x141, 0, CCLKCFG, -1, -1}, /* 199, 199, 99, 99 */
+ {265400, 132700, 0x143, 1, CCLKCFG, -1, -1}, /* 265, 265, 133, 66 */
+ {331800, 165900, 0x145, 1, CCLKCFG, -1, -1}, /* 331, 331, 166, 83 */
+ {398100, 99500, 0x161, 0, CCLKCFG, -1, -1}, /* 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, -1, -1}, /* 99, 99, 50, 50 */
+ {199100, 99500, 0x221, 0, CCLKCFG, -1, -1}, /* 99, 199, 50, 99 */
+ {298500, 99500, 0x321, 0, CCLKCFG, -1, -1}, /* 99, 287, 50, 99 */
+ {298600, 99500, 0x1c1, 0, CCLKCFG, -1, -1}, /* 199, 287, 99, 99 */
+ {398100, 99500, 0x241, 0, CCLKCFG, -1, -1}, /* 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), 900000, 1705000 },
+ {156000, 104000, PXA27x_CCCR(1, 8, 3), 0, CCLKCFG2(1, 0, 1), 1000000, 1705000 },
+ {208000, 208000, PXA27x_CCCR(0, 16, 2), 1, CCLKCFG2(0, 0, 1), 1180000, 1705000 },
+ {312000, 208000, PXA27x_CCCR(1, 16, 3), 1, CCLKCFG2(1, 0, 1), 1250000, 1705000 },
+ {416000, 208000, PXA27x_CCCR(1, 16, 4), 1, CCLKCFG2(1, 0, 1), 1350000, 1705000 },
+ {520000, 208000, PXA27x_CCCR(1, 16, 5), 1, CCLKCFG2(1, 0, 1), 1450000, 1705000 },
+ {624000, 208000, PXA27x_CCCR(1, 16, 6), 1, CCLKCFG2(1, 0, 1), 1550000, 1705000 }
+};
+
+#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);
+
+#ifdef CONFIG_REGULATOR
+
+static int pxa_cpufreq_change_voltage(pxa_freqs_t *pxa_freq)
+{
+ int ret = 0;
+ int vmin, vmax;
+
+ if (!cpu_is_pxa27x())
+ return 0;
+
+ vmin = pxa_freq->vmin;
+ vmax = pxa_freq->vmax;
+ if ((vmin == -1) || (vmax == -1))
+ return 0;
+
+ ret = regulator_set_voltage(vcc_core, vmin, vmax);
+ if (ret)
+ pr_err("cpufreq: Failed to set vcc_core in [%dmV..%dmV]\n",
+ vmin, vmax);
+ return ret;
+}
+
+static __init void pxa_cpufreq_init_voltages(void)
+{
+ vcc_core = regulator_get(NULL, "vcc_core");
+ if (IS_ERR(vcc_core)) {
+ pr_info("cpufreq: Didn't find vcc_core regulator\n");
+ vcc_core = NULL;
+ } else {
+ pr_info("cpufreq: Found vcc_core regulator\n");
+ }
+}
+#else
+static int pxa_cpufreq_change_voltage(pxa_freqs_t *pxa_freq)
+{
+ return 0;
+}
+
+static __init void pxa_cpufreq_init_voltages(void) { }
+#endif
+
+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 = __raw_readl(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 interval = freq * SDRAM_TREF / sdram_rows;
+
+ return (interval - (cpu_is_pxa27x() ? 31 : 0)) / 32;
+}
+
+/* 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;
+ int ret = 0;
+
+ /* 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("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));
+
+ if (vcc_core && freqs.new > freqs.old)
+ ret = pxa_cpufreq_change_voltage(&pxa_freq_settings[idx]);
+ if (ret)
+ return ret;
+ /*
+ * 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 = __raw_readl(MDREFR);
+ if ((preset_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);
+
+ /*
+ * Even if voltage setting fails, we don't report it, as the frequency
+ * change succeeded. The voltage reduction is not a critical failure,
+ * only power savings will suffer from this.
+ *
+ * Note: if the voltage change fails, and a return value is returned, a
+ * bug is triggered (seems a deadlock). Should anybody find out where,
+ * the "return 0" should become a "return ret".
+ */
+ if (vcc_core && freqs.new < freqs.old)
+ ret = pxa_cpufreq_change_voltage(&pxa_freq_settings[idx]);
+
+ return 0;
+}
+
+static 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();
+
+ pxa_cpufreq_init_voltages();
+
+ 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].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);
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