From: Ziggy <ziggy@ziggy471.com>
Date: Tue, 4 Sep 2012 12:49:22 +0000 (-0400)
Subject: Add sysfs vdd interface
X-Git-Url: https://ziggy471.com/git/gitweb.cgi?p=ziggy471-shooter-ics-kernel.git;a=commitdiff;h=fb55e2f1906133e7850fc100856f8ad2b0f5adf3

Add sysfs vdd interface
---

--- a/arch/arm/mach-msm/acpuclock-8x60.c
+++ b/arch/arm/mach-msm/acpuclock-8x60.c
@@ -889,3 +889,36 @@ static int __init acpuclk_8x60_init(stru
 struct acpuclk_soc_data acpuclk_8x60_soc_data __initdata = {
 	.init = acpuclk_8x60_init,
 };
+
+#ifdef CONFIG_VDD_USERSPACE
+ssize_t acpuclk_get_vdd_levels_str(char *buf)
+{
+	int i, len = 0;
+	if (buf) {
+		mutex_lock(&drv_state.lock);
+		len += sprintf(buf + len, "Min: %4d\n", MIN_VDD_SC);
+		len += sprintf(buf + len, "Max: %4d\n", MAX_VDD_SC);
+		for (i = 0; acpu_freq_tbl[i].acpuclk_khz; i++) {
+			if (acpu_freq_tbl[i].use_for_scaling[0] || acpu_freq_tbl[i].use_for_scaling[1]) {
+				len += sprintf(buf + len, "%8u: %4d\n", acpu_freq_tbl[i].acpuclk_khz, acpu_freq_tbl[i].vdd_sc);
+			}
+		}
+		mutex_unlock(&drv_state.lock);
+	}
+	return len;
+}
+
+void acpuclk_set_vdd(unsigned int khz, int vdd)
+{
+	int i;
+	vdd = vdd / 25 * 25;	//! regulator only accepts multiples of 25 (mV)
+	mutex_lock(&drv_state.lock);
+	for (i = 0; acpu_freq_tbl[i].acpuclk_khz; i++) {
+		if (khz == 0)
+			acpu_freq_tbl[i].vdd_sc = min(max((unsigned int)(acpu_freq_tbl[i].vdd_sc + vdd), (unsigned int)MIN_VDD_SC), (unsigned int)MAX_VDD_SC);
+		else if (acpu_freq_tbl[i].acpuclk_khz == khz)
+			acpu_freq_tbl[i].vdd_sc = min(max((unsigned int)vdd, (unsigned int)MIN_VDD_SC), (unsigned int)MAX_VDD_SC);
+	}
+	mutex_unlock(&drv_state.lock);
+}
+#endif
--- a/arch/arm/mach-msm/cpufreq.c
+++ b/arch/arm/mach-msm/cpufreq.c
@@ -219,6 +219,10 @@ static int __cpuinit msm_cpufreq_init(st
 	init_completion(&cpu_work->complete);
 #endif
 
+#ifdef CONFIG_MSM_CPU_FREQ_SET_MIN_MAX
+	policy->min = CONFIG_MSM_CPU_FREQ_MIN;
+	policy->max = CONFIG_MSM_CPU_FREQ_MAX;
+#endif
 	return 0;
 }
 
@@ -231,6 +235,8 @@ static int msm_cpufreq_suspend(void)
 		per_cpu(cpufreq_suspend, cpu).device_suspended = 1;
 		mutex_unlock(&per_cpu(cpufreq_suspend, cpu).suspend_mutex);
 	}
+	if (num_online_cpus() > 1)
+		cpu_down(1);
 
 	return NOTIFY_DONE;
 }
--- a/drivers/cpufreq/Kconfig
+++ b/drivers/cpufreq/Kconfig
@@ -290,6 +290,14 @@ config CPU_FREQ_SAMPLING_LATENCY_MULTIPL
 	  Sampling latency rate multiplied by the cpu switch latency.
 	  Affects governor polling.
 
+config VDD_USERSPACE
+	bool "VDD sysfs interface"
+	default n
+	depends on CPU_FREQ_STAT
+	help
+	  exposes the VDD table to userspace
+	  allows users to adjust voltages on the fly
+
 menu "x86 CPU frequency scaling drivers"
 depends on X86
 source "drivers/cpufreq/Kconfig.x86"
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -576,6 +576,59 @@ static ssize_t show_bios_limit(struct cp
 	return sprintf(buf, "%u\n", policy->cpuinfo.max_freq);
 }
 
+#ifdef CONFIG_VDD_USERSPACE
+extern ssize_t acpuclk_get_vdd_levels_str(char *buf);
+static ssize_t show_vdd_levels(struct kobject *a, struct attribute *b, char *buf)
+{
+	return acpuclk_get_vdd_levels_str(buf);
+}
+
+extern void acpuclk_set_vdd(unsigned acpu_khz, int vdd);
+static ssize_t store_vdd_levels(struct kobject *a, struct attribute *b, const char *buf, size_t count)
+{
+	int i = 0, j;
+	int pair[2] = { 0, 0 };
+	int sign = 0;
+	if (count < 1)
+		return 0;
+	if (buf[0] == '-') {
+		sign = -1;
+		i++;
+	}
+	else if (buf[0] == '+') {
+		sign = 1;
+		i++;
+	}
+	for (j = 0; i < count; i++) {
+		char c = buf[i];
+		if ((c >= '0') && (c <= '9')) {
+			pair[j] *= 10;
+			pair[j] += (c - '0');
+		}
+		else if ((c == ' ') || (c == '\t')) {
+			if (pair[j] != 0) {
+				j++;
+				if ((sign != 0) || (j > 1))
+					break;
+			}
+		}
+		else
+			break;
+	}
+	if (sign != 0) {
+		if (pair[0] > 0)
+			acpuclk_set_vdd(0, sign * pair[0]);
+	}
+	else {
+		if ((pair[0] > 0) && (pair[1] > 0))
+			acpuclk_set_vdd((unsigned)pair[0], pair[1]);
+		else
+			return -EINVAL;
+	}
+	return count;
+}
+#endif  /* CONFIG_VDD_USERSPACE */
+
 cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400);
 cpufreq_freq_attr_ro(cpuinfo_min_freq);
 cpufreq_freq_attr_ro(cpuinfo_max_freq);
@@ -591,6 +644,10 @@ cpufreq_freq_attr_rw(scaling_max_freq);
 cpufreq_freq_attr_rw(scaling_governor);
 cpufreq_freq_attr_rw(scaling_setspeed);
 
+#ifdef CONFIG_VDD_USERSPACE
+define_one_global_rw(vdd_levels);
+#endif
+
 static struct attribute *default_attrs[] = {
 	&cpuinfo_min_freq.attr,
 	&cpuinfo_max_freq.attr,
@@ -606,6 +663,18 @@ static struct attribute *default_attrs[]
 	NULL
 };
 
+#ifdef CONFIG_VDD_USERSPACE
+static struct attribute *vddtbl_attrs[] = {
+	&vdd_levels.attr,
+	NULL
+};
+
+static struct attribute_group vddtbl_attr_group = {
+	.attrs = vddtbl_attrs,
+	.name = "vdd_table",
+};
+#endif	/* CONFIG_VDD_USERSPACE */
+
 struct kobject *cpufreq_global_kobject;
 EXPORT_SYMBOL(cpufreq_global_kobject);
 
@@ -1916,6 +1985,9 @@ EXPORT_SYMBOL_GPL(cpufreq_unregister_dri
 static int __init cpufreq_core_init(void)
 {
 	int cpu;
+#ifdef CONFIG_VDD_USERSPACE
+	int rc;
+#endif	/* CONFIG_VDD_USERSPACE */
 
 	for_each_possible_cpu(cpu) {
 		per_cpu(cpufreq_policy_cpu, cpu) = -1;
@@ -1927,6 +1999,10 @@ static int __init cpufreq_core_init(void
 	BUG_ON(!cpufreq_global_kobject);
 	register_syscore_ops(&cpufreq_syscore_ops);
 
+#ifdef CONFIG_VDD_USERSPACE
+	rc = sysfs_create_group(cpufreq_global_kobject, &vddtbl_attr_group);
+#endif	/* CONFIG_VDD_USERSPACE */
+
 	return 0;
 }
 core_initcall(cpufreq_core_init);