ARM: tegra: clock: Support sysfs shared bus rate nodes

Added mechanism to expose shared bus available rates and current rate
via sysfs. Updated shared bus limits initialization, so that all sysfs
nodes (caps, floors, rates) re-use the same attribute array. Converted
bus limit level field to unsigned type.

Change-Id: I53f6fec2f9700277f9d67ec9960f372c1c3b6c08
Signed-off-by: Alex Frid <afrid@nvidia.com>
Reviewed-on: http://git-master/r/269856
Reviewed-by: Kaz Fukuoka <kfukuoka@nvidia.com>
Reviewed-by: Yu-Huan Hsu <yhsu@nvidia.com>

1 files changed, 99 insertions, 11 deletions

diff --git a/arch/arm/mach-tegra/tegra_core_volt_cap.c b/arch/arm/mach-tegra/tegra_core_volt_cap.c
index a0818828e1f1..420fa0ac29b0 100644
--- a/arch/arm/mach-tegra/tegra_core_volt_cap.c
+++ b/arch/arm/mach-tegra/tegra_core_volt_cap.c
@@ -312,8 +312,7 @@ int __init tegra_init_core_cap(
 #define MAX_BUS_NUM	8
 
 static DEFINE_MUTEX(bus_limit_lock);
-static const struct attribute *bus_cap_attributes[2 * MAX_BUS_NUM + 1];
-static const struct attribute *bus_floor_attributes[2 * MAX_BUS_NUM + 1];
+static const struct attribute *bus_attributes[2 * MAX_BUS_NUM + 1];
 
 static int _floor_update(struct core_bus_limit_table *bus_limit,
 			 unsigned long qos_limit_level)
@@ -434,7 +433,7 @@ bus_limit_level_show(struct kobject *kobj, struct kobj_attribute *attr,
 		    char *buf)
 {
 	struct core_bus_limit_table *bus_limit = level_to_bus(attr);
-	return sprintf(buf, "%d\n", bus_limit->level);
+	return sprintf(buf, "%lu\n", bus_limit->level);
 }
 static ssize_t
 bus_limit_level_store(struct kobject *kobj, struct kobj_attribute *attr,
@@ -491,8 +490,8 @@ int __init tegra_init_shared_bus_cap(
 		table[i].level_attr.show = bus_limit_level_show;
 		table[i].level_attr.store = bus_limit_level_store;
 		table[i].update = _cap_update;
-		bus_cap_attributes[j++] = &table[i].refcnt_attr.attr;
-		bus_cap_attributes[j++] = &table[i].level_attr.attr;
+		bus_attributes[j++] = &table[i].refcnt_attr.attr;
+		bus_attributes[j++] = &table[i].level_attr.attr;
 		if (table[i].pm_qos_class) {
 			table[i].qos_nb.notifier_call = qos_limit_notify;
 			if (pm_qos_add_notifier(
@@ -503,9 +502,9 @@ int __init tegra_init_shared_bus_cap(
 			}
 		}
 	}
-	bus_cap_attributes[j] = NULL;
+	bus_attributes[j] = NULL;
 
-	if (!cap_kobj || sysfs_create_files(cap_kobj, bus_cap_attributes))
+	if (!cap_kobj || sysfs_create_files(cap_kobj, bus_attributes))
 		return -ENOMEM;
 	return 0;
 }
@@ -534,8 +533,8 @@ int __init tegra_init_shared_bus_floor(
 		table[i].level_attr.show = bus_limit_level_show;
 		table[i].level_attr.store = bus_limit_level_store;
 		table[i].update = _floor_update;
-		bus_floor_attributes[j++] = &table[i].refcnt_attr.attr;
-		bus_floor_attributes[j++] = &table[i].level_attr.attr;
+		bus_attributes[j++] = &table[i].refcnt_attr.attr;
+		bus_attributes[j++] = &table[i].level_attr.attr;
 		if (table[i].pm_qos_class) {
 			table[i].qos_nb.notifier_call = qos_limit_notify;
 			if (pm_qos_add_notifier(
@@ -546,9 +545,98 @@ int __init tegra_init_shared_bus_floor(
 			}
 		}
 	}
-	bus_floor_attributes[j] = NULL;
+	bus_attributes[j] = NULL;
 
-	if (!floor_kobj || sysfs_create_files(floor_kobj, bus_floor_attributes))
+	if (!floor_kobj || sysfs_create_files(floor_kobj, bus_attributes))
+		return -ENOMEM;
+	return 0;
+}
+
+/* sysfs interfaces to read tegra core shared bus current / available rates */
+#define rate_to_bus(attr) \
+	container_of(attr, struct core_bus_rates_table, rate_attr)
+#define available_rates_to_bus(attr) \
+	container_of(attr, struct core_bus_rates_table, available_rates_attr)
+
+
+static ssize_t
+bus_rate_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+	struct core_bus_rates_table *bus = rate_to_bus(attr);
+	struct clk *c = bus->bus_clk;
+	return sprintf(buf, "%lu\n", clk_get_rate(c));
+}
+
+static ssize_t
+bus_available_rates_show(struct kobject *kobj, struct kobj_attribute *attr,
+			 char *buf)
+{
+	int i;
+	ssize_t n = 0;
+	struct core_bus_rates_table *bus = available_rates_to_bus(attr);
+
+	for (i = 0; i < MAX_DVFS_FREQS; i++) {
+		unsigned long rate = bus->available_rates[i];
+		if (!rate || ((n + 10) > PAGE_SIZE))
+			break;
+
+		n += sprintf(&buf[n], "%lu ", rate);
+	}
+	n = n ? n-1 : 0;
+	n += sprintf(&buf[n], "\n");
+	return n;
+}
+
+static int get_available_rates(struct clk *c, struct core_bus_rates_table *t)
+{
+	int i = 0;
+	unsigned long rate = 0;
+	unsigned long max_rate = clk_get_max_rate(c);
+
+	/* available rates search below applied to shared bus only */
+	if (!c->ops || !c->ops->round_rate || !c->ops->shared_bus_update) {
+		pr_err("%s: cannot find %s rates ladder\n", __func__, c->name);
+		return -ENOSYS;
+	}
+
+	/* shared bus clock must round up, unless top of range reached */
+	while ((rate <= max_rate) && (i <= MAX_DVFS_FREQS)) {
+		unsigned long rounded_rate = clk_round_rate(c, rate);
+		if (IS_ERR_VALUE(rounded_rate) || (rounded_rate <= rate))
+			break;
+
+		rate = rounded_rate + 2000;	/* 2kHz resolution */
+		t->available_rates[i++] = rounded_rate;
+	}
+	return 0;
+}
+
+int __init tegra_init_sysfs_shared_bus_rate(
+	struct core_bus_rates_table *table, int table_size,
+	struct kobject *floor_kobj)
+{
+	int i, j;
+	struct clk *c = NULL;
+
+	if (!table || !table_size || (table_size > MAX_BUS_NUM))
+		return -EINVAL;
+
+	for (i = 0, j = 0; i < table_size; i++) {
+		c = tegra_get_clock_by_name(table[i].bus_clk_name);
+		if (!c || get_available_rates(c, &table[i])) {
+			pr_err("%s: failed to initialize %s table\n",
+			       __func__, table[i].bus_clk_name);
+			continue;
+		}
+		table[i].bus_clk = c;
+		table[i].rate_attr.show = bus_rate_show;
+		table[i].available_rates_attr.show = bus_available_rates_show;
+		bus_attributes[j++] = &table[i].rate_attr.attr;
+		bus_attributes[j++] = &table[i].available_rates_attr.attr;
+	}
+	bus_attributes[j] = NULL;
+
+	if (!floor_kobj || sysfs_create_files(floor_kobj, bus_attributes))
 		return -ENOMEM;
 	return 0;
 }