* Licensed under the terms of the GNU GPL License version 2.
* Based upon datasheets & sample CPUs kindly provided by VIA.
*
- * VIA have currently 2 different versions of Longhaul.
+ * VIA have currently 3 different versions of Longhaul.
* Version 1 (Longhaul) uses the BCR2 MSR at 0x1147.
- * It is present only in Samuel 1, Samuel 2 and Ezra.
- * Version 2 (Powersaver) uses the POWERSAVER MSR at 0x110a.
- * It is present in Ezra-T, Nehemiah and above.
- * In addition to scaling multiplier, it can also scale voltage.
- * There is provision for scaling FSB too, but this doesn't work
- * too well in practice.
+ * It is present only in Samuel 1 (C5A), Samuel 2 (C5B) stepping 0.
+ * Version 2 of longhaul is the same as v1, but adds voltage scaling.
+ * Present in Samuel 2 (steppings 1-7 only) (C5B), and Ezra (C5C)
+ * voltage scaling support has currently been disabled in this driver
+ * until we have code that gets it right.
+ * Version 3 of longhaul got renamed to Powersaver and redesigned
+ * to use the POWERSAVER MSR at 0x110a.
+ * It is present in Ezra-T (C5M), Nehemiah (C5X) and above.
+ * It's pretty much the same feature wise to longhaul v2, though
+ * there is provision for scaling FSB too, but this doesn't work
+ * too well in practice so we don't even try to use this.
*
* BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous*
*/
#define PFX "longhaul: "
+#define TYPE_LONGHAUL_V1 1
+#define TYPE_LONGHAUL_V2 2
+#define TYPE_POWERSAVER 3
+
+#define CPU_SAMUEL 1
+#define CPU_SAMUEL2 2
+#define CPU_EZRA 3
+#define CPU_EZRA_T 4
+#define CPU_NEHEMIAH 5
+
+static int cpu_model;
static unsigned int numscales=16, numvscales;
static unsigned int fsb;
static int minvid, maxvid;
static unsigned int highest_speed, lowest_speed; /* kHz */
static int longhaul_version;
static struct cpufreq_frequency_table *longhaul_table;
+static char speedbuffer[8];
+
+static char *print_speed(int speed)
+{
+ if (speed > 1000) {
+ if (speed%1000 == 0)
+ sprintf (speedbuffer, "%dGHz", speed/1000);
+ else
+ sprintf (speedbuffer, "%d.%dGHz", speed/1000, (speed%1000)/100);
+ } else
+ sprintf (speedbuffer, "%dMHz", speed);
+
+ return speedbuffer;
+}
-static unsigned int calc_speed(int mult, int fsb)
+static unsigned int calc_speed(int mult)
{
int khz;
khz = (mult/10)*fsb;
rdmsr (MSR_IA32_EBL_CR_POWERON, lo, hi);
invalue = (lo & (1<<22|1<<23|1<<24|1<<25)) >>22;
- if (longhaul_version==2 || longhaul_version==3) {
+ if (longhaul_version==TYPE_LONGHAUL_V2 || longhaul_version==TYPE_POWERSAVER) {
if (lo & (1<<27))
invalue+=16;
}
}
+static void do_powersaver(union msr_longhaul *longhaul,
+ unsigned int clock_ratio_index)
+{
+ int version;
+
+ switch (cpu_model) {
+ case CPU_EZRA_T:
+ version = 3;
+ break;
+ case CPU_NEHEMIAH:
+ version = 0xf;
+ break;
+ default:
+ return;
+ }
+
+ rdmsrl(MSR_VIA_LONGHAUL, longhaul->val);
+ longhaul->bits.SoftBusRatio = clock_ratio_index & 0xf;
+ longhaul->bits.SoftBusRatio4 = (clock_ratio_index & 0x10) >> 4;
+ longhaul->bits.EnableSoftBusRatio = 1;
+ longhaul->bits.RevisionKey = 0;
+ local_irq_disable();
+ wrmsrl(MSR_VIA_LONGHAUL, longhaul->val);
+ local_irq_enable();
+ __hlt();
+
+ rdmsrl(MSR_VIA_LONGHAUL, longhaul->val);
+ longhaul->bits.EnableSoftBusRatio = 0;
+ longhaul->bits.RevisionKey = version;
+ local_irq_disable();
+ wrmsrl(MSR_VIA_LONGHAUL, longhaul->val);
+ local_irq_enable();
+}
+
/**
* longhaul_set_cpu_frequency()
* @clock_ratio_index : bitpattern of the new multiplier.
*
- * Sets a new clock ratio, and -if applicable- a new Front Side Bus
+ * Sets a new clock ratio.
*/
static void longhaul_setstate(unsigned int clock_ratio_index)
struct cpufreq_freqs freqs;
union msr_longhaul longhaul;
union msr_bcr2 bcr2;
+ static unsigned int old_ratio=-1;
+
+ if (old_ratio == clock_ratio_index)
+ return;
+ old_ratio = clock_ratio_index;
mult = clock_ratio[clock_ratio_index];
if (mult == -1)
return;
- speed = calc_speed (mult, fsb);
+ speed = calc_speed(mult);
if ((speed > highest_speed) || (speed < lowest_speed))
return;
- freqs.old = calc_speed (longhaul_get_cpu_mult(), fsb);
+ freqs.old = calc_speed(longhaul_get_cpu_mult());
freqs.new = speed;
freqs.cpu = 0; /* longhaul.c is UP only driver */
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
- dprintk (KERN_INFO PFX "FSB:%d Mult:%d.%dx\n", fsb, mult/10, mult%10);
+ dprintk (KERN_INFO PFX "Setting to FSB:%dMHz Mult:%d.%dx (%s)\n",
+ fsb, mult/10, mult%10, print_speed(speed/1000));
switch (longhaul_version) {
- case 1:
+
+ /*
+ * Longhaul v1. (Samuel[C5A] and Samuel2 stepping 0[C5B])
+ * Software controlled multipliers only.
+ *
+ * *NB* Until we get voltage scaling working v1 & v2 are the same code.
+ * Longhaul v2 appears in Samuel2 Steppings 1->7 [C5b] and Ezra [C5C]
+ */
+ case TYPE_LONGHAUL_V1:
+ case TYPE_LONGHAUL_V2:
rdmsrl (MSR_VIA_BCR2, bcr2.val);
/* Enable software clock multiplier */
bcr2.bits.ESOFTBF = 1;
bcr2.bits.CLOCKMUL = clock_ratio_index;
+ local_irq_disable();
wrmsrl (MSR_VIA_BCR2, bcr2.val);
+ local_irq_enable();
__hlt();
/* Disable software clock multiplier */
rdmsrl (MSR_VIA_BCR2, bcr2.val);
bcr2.bits.ESOFTBF = 0;
+ local_irq_disable();
wrmsrl (MSR_VIA_BCR2, bcr2.val);
+ local_irq_enable();
break;
/*
- * Powersaver. (Ezra-T [C5M], Nehemiah [C5N])
+ * Longhaul v3 (aka Powersaver). (Ezra-T [C5M] & Nehemiah [C5N])
* We can scale voltage with this too, but that's currently
* disabled until we come up with a decent 'match freq to voltage'
* algorithm.
- * We also need to do the voltage/freq setting in order depending
- * on the direction of scaling (like we do in powernow-k7.c)
- * Ezra-T was alleged to do FSB scaling too, but it never worked in practice.
+ * When we add voltage scaling, we will also need to do the
+ * voltage/freq setting in order depending on the direction
+ * of scaling (like we do in powernow-k7.c)
+ * Nehemiah can do FSB scaling too, but this has never been proven
+ * to work in practice.
*/
- case 2:
- rdmsrl (MSR_VIA_LONGHAUL, longhaul.val);
- longhaul.bits.SoftBusRatio = clock_ratio_index & 0xf;
- longhaul.bits.SoftBusRatio4 = (clock_ratio_index & 0x10) >> 4;
- longhaul.bits.EnableSoftBusRatio = 1;
- /* We must program the revision key only with values we
- * know about, not blindly copy it from 0:3 */
- longhaul.bits.RevisionKey = 3; /* SoftVID & SoftBSEL */
- wrmsrl(MSR_VIA_LONGHAUL, longhaul.val);
- __hlt();
-
- rdmsrl (MSR_VIA_LONGHAUL, longhaul.val);
- longhaul.bits.EnableSoftBusRatio = 0;
- longhaul.bits.RevisionKey = 3;
- wrmsrl (MSR_VIA_LONGHAUL, longhaul.val);
- break;
- case 3:
- rdmsrl (MSR_VIA_LONGHAUL, longhaul.val);
- longhaul.bits.SoftBusRatio = clock_ratio_index & 0xf;
- longhaul.bits.SoftBusRatio4 = (clock_ratio_index & 0x10) >> 4;
- longhaul.bits.EnableSoftBusRatio = 1;
-
- longhaul.bits.RevisionKey = 0x0;
-
- wrmsrl(MSR_VIA_LONGHAUL, longhaul.val);
- __hlt();
-
- rdmsrl (MSR_VIA_LONGHAUL, longhaul.val);
- longhaul.bits.EnableSoftBusRatio = 0;
- longhaul.bits.RevisionKey = 0xf;
- wrmsrl (MSR_VIA_LONGHAUL, longhaul.val);
+ case TYPE_POWERSAVER:
+ do_powersaver(&longhaul, clock_ratio_index);
break;
}
static int __init longhaul_get_ranges(void)
{
- struct cpuinfo_x86 *c = cpu_data;
unsigned long invalue;
unsigned int multipliers[32]= {
50,30,40,100,55,35,45,95,90,70,80,60,120,75,85,65,
unsigned int eblcr_fsb_table_v2[] = { 133, 100, -1, 66 };
switch (longhaul_version) {
- case 1:
+ case TYPE_LONGHAUL_V1:
+ case TYPE_LONGHAUL_V2:
/* Ugh, Longhaul v1 didn't have the min/max MSRs.
Assume min=3.0x & max = whatever we booted at. */
minmult = 30;
maxmult = longhaul_get_cpu_mult();
rdmsr (MSR_IA32_EBL_CR_POWERON, lo, hi);
invalue = (lo & (1<<18|1<<19)) >>18;
- if (c->x86_model==6)
+ if (cpu_model==CPU_SAMUEL || cpu_model==CPU_SAMUEL2)
fsb = eblcr_fsb_table_v1[invalue];
else
fsb = guess_fsb();
break;
- case 2:
- rdmsrl (MSR_VIA_LONGHAUL, longhaul.val);
-
- invalue = longhaul.bits.MaxMHzBR;
- if (longhaul.bits.MaxMHzBR4)
- invalue += 16;
- maxmult=multipliers[invalue];
-
- invalue = longhaul.bits.MinMHzBR;
- if (longhaul.bits.MinMHzBR4 == 1)
- minmult = 30;
- else
- minmult = multipliers[invalue];
-
- fsb = eblcr_fsb_table_v2[longhaul.bits.MaxMHzFSB];
- break;
+ case TYPE_POWERSAVER:
+ /* Ezra-T */
+ if (cpu_model==CPU_EZRA_T) {
+ rdmsrl (MSR_VIA_LONGHAUL, longhaul.val);
+ invalue = longhaul.bits.MaxMHzBR;
+ if (longhaul.bits.MaxMHzBR4)
+ invalue += 16;
+ maxmult=multipliers[invalue];
+
+ invalue = longhaul.bits.MinMHzBR;
+ if (longhaul.bits.MinMHzBR4 == 1)
+ minmult = 30;
+ else
+ minmult = multipliers[invalue];
+ fsb = eblcr_fsb_table_v2[longhaul.bits.MaxMHzFSB];
+ break;
+ }
- case 3:
- rdmsrl (MSR_VIA_LONGHAUL, longhaul.val);
-
- /*
- * TODO: This code works, but raises a lot of questions.
- * - Some Nehemiah's seem to have broken Min/MaxMHzBR's.
- * We get around this by using a hardcoded multiplier of 5.0x
- * for the minimimum speed, and the speed we booted up at for the max.
- * This is done in longhaul_get_cpu_mult() by reading the EBLCR register.
- * - According to some VIA documentation EBLCR is only
- * in pre-Nehemiah C3s. How this still works is a mystery.
- * We're possibly using something undocumented and unsupported,
- * But it works, so we don't grumble.
- */
- minmult=50;
- maxmult=longhaul_get_cpu_mult();
-
- fsb = eblcr_fsb_table_v2[longhaul.bits.MaxMHzFSB];
- break;
+ /* Nehemiah */
+ if (cpu_model==CPU_NEHEMIAH) {
+ rdmsrl (MSR_VIA_LONGHAUL, longhaul.val);
+
+ /*
+ * TODO: This code works, but raises a lot of questions.
+ * - Some Nehemiah's seem to have broken Min/MaxMHzBR's.
+ * We get around this by using a hardcoded multiplier of 4.0x
+ * for the minimimum speed, and the speed we booted up at for the max.
+ * This is done in longhaul_get_cpu_mult() by reading the EBLCR register.
+ * - According to some VIA documentation EBLCR is only
+ * in pre-Nehemiah C3s. How this still works is a mystery.
+ * We're possibly using something undocumented and unsupported,
+ * But it works, so we don't grumble.
+ */
+ minmult=40;
+ maxmult=longhaul_get_cpu_mult();
+
+ /* Starting with the 1.2GHz parts, theres a 200MHz bus. */
+ if ((cpu_khz/1000) > 1200)
+ fsb = 200;
+ else
+ fsb = eblcr_fsb_table_v2[longhaul.bits.MaxMHzFSB];
+ break;
+ }
}
- dprintk (KERN_INFO PFX "MinMult=%d.%dx MaxMult=%d.%dx\n",
+ dprintk (KERN_INFO PFX "MinMult:%d.%dx MaxMult:%d.%dx\n",
minmult/10, minmult%10, maxmult/10, maxmult%10);
if (fsb == -1) {
return -EINVAL;
}
- highest_speed = calc_speed (maxmult, fsb);
- lowest_speed = calc_speed (minmult,fsb);
- dprintk (KERN_INFO PFX "FSB: %dMHz Lowestspeed=%dMHz Highestspeed=%dMHz\n",
- fsb, lowest_speed/1000, highest_speed/1000);
+ highest_speed = calc_speed(maxmult);
+ lowest_speed = calc_speed(minmult);
+ dprintk (KERN_INFO PFX "FSB:%dMHz ", fsb);
+ dprintk ("Lowest speed:%s ", print_speed(lowest_speed/1000));
+ dprintk ("Highest speed:%s\n", print_speed(highest_speed/1000));
if (lowest_speed == highest_speed) {
printk (KERN_INFO PFX "highestspeed == lowest, aborting.\n");
continue;
if (ratio > maxmult || ratio < minmult)
continue;
- longhaul_table[k].frequency = calc_speed (ratio, fsb);
+ longhaul_table[k].frequency = calc_speed(ratio);
longhaul_table[k].index = j;
k++;
}
static int longhaul_target(struct cpufreq_policy *policy,
- unsigned int target_freq,
- unsigned int relation)
+ unsigned int target_freq, unsigned int relation)
{
unsigned int table_index = 0;
unsigned int new_clock_ratio = 0;
return 0;
}
+
static unsigned int longhaul_get(unsigned int cpu)
{
if (cpu)
return 0;
- return (calc_speed (longhaul_get_cpu_mult(), fsb));
+ return calc_speed(longhaul_get_cpu_mult());
}
+
static int __init longhaul_cpu_init(struct cpufreq_policy *policy)
{
struct cpuinfo_x86 *c = cpu_data;
switch (c->x86_model) {
case 6:
+ cpu_model = CPU_SAMUEL;
cpuname = "C3 'Samuel' [C5A]";
- longhaul_version=1;
+ longhaul_version = TYPE_LONGHAUL_V1;
memcpy (clock_ratio, samuel1_clock_ratio, sizeof(samuel1_clock_ratio));
memcpy (eblcr_table, samuel1_eblcr, sizeof(samuel1_eblcr));
break;
- case 7: /* C5B / C5C */
- longhaul_version=1;
+ case 7:
+ longhaul_version = TYPE_LONGHAUL_V1;
switch (c->x86_mask) {
case 0:
+ cpu_model = CPU_SAMUEL2;
cpuname = "C3 'Samuel 2' [C5B]";
/* Note, this is not a typo, early Samuel2's had Samuel1 ratios. */
memcpy (clock_ratio, samuel1_clock_ratio, sizeof(samuel1_clock_ratio));
memcpy (eblcr_table, samuel2_eblcr, sizeof(samuel2_eblcr));
break;
case 1 ... 15:
- if (c->x86_mask < 8)
+ if (c->x86_mask < 8) {
+ cpu_model = CPU_SAMUEL2;
cpuname = "C3 'Samuel 2' [C5B]";
- else
+ } else {
+ cpu_model = CPU_EZRA;
cpuname = "C3 'Ezra' [C5C]";
+ }
memcpy (clock_ratio, ezra_clock_ratio, sizeof(ezra_clock_ratio));
memcpy (eblcr_table, ezra_eblcr, sizeof(ezra_eblcr));
break;
break;
case 8:
+ cpu_model = CPU_EZRA_T;
cpuname = "C3 'Ezra-T' [C5M]";
- longhaul_version=2;
+ longhaul_version = TYPE_POWERSAVER;
numscales=32;
memcpy (clock_ratio, ezrat_clock_ratio, sizeof(ezrat_clock_ratio));
memcpy (eblcr_table, ezrat_eblcr, sizeof(ezrat_eblcr));
break;
case 9:
- longhaul_version=3;
+ cpu_model = CPU_NEHEMIAH;
+ longhaul_version = TYPE_POWERSAVER;
numscales=32;
switch (c->x86_mask) {
case 0 ... 1:
break;
}
- printk (KERN_INFO PFX "VIA %s CPU detected. Longhaul v%d supported.\n",
- cpuname, longhaul_version);
+ printk (KERN_INFO PFX "VIA %s CPU detected. ", cpuname);
+ switch (longhaul_version) {
+ case TYPE_LONGHAUL_V1:
+ case TYPE_LONGHAUL_V2:
+ printk ("Longhaul v%d supported.\n", longhaul_version);
+ break;
+ case TYPE_POWERSAVER:
+ printk ("Powersaver supported.\n");
+ break;
+ };
ret = longhaul_get_ranges();
if (ret != 0)
return ret;
- if ((longhaul_version==2) && (dont_scale_voltage==0))
+ if ((longhaul_version==TYPE_LONGHAUL_V2 || longhaul_version==TYPE_POWERSAVER) &&
+ (dont_scale_voltage==0))
longhaul_setup_voltagescaling();
policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
- policy->cur = calc_speed (longhaul_get_cpu_mult(), fsb);
+ policy->cur = calc_speed(longhaul_get_cpu_mult());
ret = cpufreq_frequency_table_cpuinfo(policy, longhaul_table);
if (ret)
.attr = longhaul_attr,
};
+
static int __init longhaul_init(void)
{
struct cpuinfo_x86 *c = cpu_data;
return -ENODEV;
}
+
static void __exit longhaul_exit(void)
{
int i=0;
- unsigned int new_clock_ratio;
-
- while (clock_ratio[i] != maxmult)
- i++;
- new_clock_ratio = longhaul_table[i].index & 0xFF;
- longhaul_setstate(new_clock_ratio);
+ for (i=0; i < numscales; i++) {
+ if (clock_ratio[i] == maxmult) {
+ longhaul_setstate(i);
+ break;
+ }
+ }
cpufreq_unregister_driver(&longhaul_driver);
kfree(longhaul_table);
git://git.onelab.eu / linux-2.6.git / blobdiff