cpufreq: Make voltage control compatible with ASV

The old approach used a fixed voltage table not compatible with ASV.

New approach uses ASV values by default.  This approach is based
on gokhanmoral's SiyahKernel UV implementation for I9100 ICS.

Also add min/max voltage enforcement.
Signed-off-by: Andrew Dodd <atd7@cornell.edu>

arch/arm/mach-s5pv210/cpu-freq_c110b.c

@@ -50,8 +50,8 @@ static unsigned int mpll_freq; /* in MHz */
 static unsigned int apll_freq_max; /* in MHz */
 static DEFINE_MUTEX(set_freq_lock);
 
-/* UV */
-extern int exp_UV_mV[5]; 
+#define CPU_UV_MV_MAX 1350000
+#define CPU_UV_MV_MIN 800000
 
 /* frequency */
 static struct cpufreq_frequency_table freq_table[] = {
@@ -509,7 +509,7 @@ static int s5pv210_cpufreq_target(struct cpufreq_policy *policy,
 	if (s3c_freqs.freqs.new == s3c_freqs.freqs.old && !first_run)
 		goto out;
 
-	arm_volt = exp_UV_mV[index]; //dvs_conf[index].arm_volt;
+	arm_volt = dvs_conf[index].arm_volt;
 	int_volt = dvs_conf[index].int_volt;
 
 	/* New clock information update */
@@ -692,8 +692,7 @@ static int s5pv210_cpufreq_target(struct cpufreq_policy *policy,
 	memcpy(&s3c_freqs.old, &s3c_freqs.new, sizeof(struct s3c_freq));
 	cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, KERN_INFO,
 			"cpufreq: Performance changed[L%d]\n", index);
-//	previous_arm_volt = dvs_conf[index].arm_volt;
-	previous_arm_volt = exp_UV_mV[index];
+	previous_arm_volt = dvs_conf[index].arm_volt;
 
 	if (first_run)
 		first_run = false;
@@ -736,7 +735,7 @@ static int s5pv210_cpufreq_resume(struct cpufreq_policy *policy)
 
 	memcpy(&s3c_freqs.old, &clk_info[level],
 			sizeof(struct s3c_freq));
-	previous_arm_volt = exp_UV_mV[level]; //dvs_conf[level].arm_volt;
+	previous_arm_volt = dvs_conf[level].arm_volt;
 
 	return ret;
 }
@@ -804,7 +803,7 @@ static int __init s5pv210_cpufreq_driver_init(struct cpufreq_policy *policy)
 
 	memcpy(&s3c_freqs.old, &clk_info[level],
 			sizeof(struct s3c_freq));
-	previous_arm_volt = exp_UV_mV[level]; //dvs_conf[level].arm_volt;
+	previous_arm_volt = dvs_conf[level].arm_volt;
 
 #ifdef CONFIG_DVFS_LIMIT
 	for(i = 0; i < DVFS_LOCK_TOKEN_NUM; i++)
@@ -914,3 +913,29 @@ static int __init s5pv210_cpufreq_init(void)
 }
 
 late_initcall(s5pv210_cpufreq_init);
+
+/* sysfs interface for UV control */
+ssize_t show_UV_mV_table(struct cpufreq_policy *policy, char *buf) {
+	return sprintf(buf, "1200mhz: %lu mV\n800mhz: %lu mV\n400mhz: %lu mV\n200mhz: %lu mV\n100mhz: %lu mV\n", dvs_conf[0].arm_volt/1000, dvs_conf[1].arm_volt/1000, dvs_conf[2].arm_volt/1000, dvs_conf[3].arm_volt/1000, dvs_conf[4].arm_volt/1000);
+}
+
+ssize_t store_UV_mV_table(struct cpufreq_policy *policy,
+				const char *buf, size_t count) {
+	unsigned int ret = -EINVAL;
+	int u[5];
+	int i = 0;
+	ret = sscanf(buf, "%d %d %d %d %d", &u[0], &u[1], &u[2], &u[3], &u[4]);
+	if(ret != 5) {
+		return -EINVAL;
+	}
+	else {
+		for( i = 0; i < 5; i++ ) {
+			if (u[i] > CPU_UV_MV_MAX / 1000) u[i] = CPU_UV_MV_MAX / 1000;
+			else if (u[i] < CPU_UV_MV_MIN / 1000) u[i] = CPU_UV_MV_MIN / 1000;
+		}
+		for( i = 0; i < 5; i++ ) {
+			dvs_conf[i].arm_volt = u[i] * 1000;
+		}
+		return count;
+	}
+}

drivers/cpufreq/cpufreq.c

@@ -32,9 +32,6 @@
 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, \
 						"cpufreq-core", msg)
 
-/* UV */
-int exp_UV_mV[5] = { 1300000, 1200000, 1050000, 950000, 950000 };
-
 /**
  * The "cpufreq driver" - the arch- or hardware-dependent low
  * level driver of CPUFreq support, and its spinlock. This lock
@@ -651,28 +648,9 @@ static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf)
 }
 
 /* sysfs interface for UV control */
-static ssize_t show_UV_mV_table(struct cpufreq_policy *policy, char *buf) {
-
-      return sprintf(buf, "1200mhz: %d mV\n800mhz: %d mV\n400mhz: %d mV\n200mhz: %d mV\n100mhz: %d mV\n", exp_UV_mV[0]/1000, exp_UV_mV[1]/1000, exp_UV_mV[2]/1000, exp_UV_mV[3]/1000, exp_UV_mV[4]/1000);
-
-}
-
-static ssize_t store_UV_mV_table(struct cpufreq_policy *policy,
-                                      const char *buf, size_t count) {
-
-      unsigned int ret = -EINVAL;
-      int i = 0;
-      ret = sscanf(buf, "%d %d %d %d %d", &exp_UV_mV[0], &exp_UV_mV[1], &exp_UV_mV[2], &exp_UV_mV[3], &exp_UV_mV[4]);
-      if(ret != 5) {
-              return -EINVAL;
-      }
-      else
-              for( i = 0; i < 5; i++ )
-              {
-                 exp_UV_mV[i] *= 1000;
-              }
-              return count;
-}
+extern ssize_t show_UV_mV_table(struct cpufreq_policy *policy, char *buf);
+extern ssize_t store_UV_mV_table(struct cpufreq_policy *policy,
+                                      const char *buf, size_t count);
 
 /**
  * show_scaling_driver - show the current cpufreq HW/BIOS limitation