[RFC PATCH 3/5] thermal: cpu_cooling: Add support to find nearby frequency levels.

[Amit Daniel Kachhap]

This patch adds suuport to get P state ceil/floor level for nearest frequency.
This will be used for consolidating ACPI cpufreq cooling via the generic cpu
cooling framework.

Signed-off-by: Amit Daniel Kachhap <amit.daniel at samsung.com>
---
 drivers/thermal/cpu_cooling.c                   |   42 +++++++++++++++++------
 drivers/thermal/samsung/exynos_thermal_common.c |    3 +-
 include/linux/cpu_cooling.h                     |   23 ++++++++++++-
 3 files changed, 55 insertions(+), 13 deletions(-)

diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c
index e2aeb36..6f5430e 100644
--- a/drivers/thermal/cpu_cooling.c
+++ b/drivers/thermal/cpu_cooling.c
@@ -120,12 +120,7 @@ static int is_cpufreq_valid(int cpu)
 	return !cpufreq_get_policy(&policy, cpu);
 }
 
-enum cpufreq_cooling_property {
-	GET_LEVEL,
-	GET_FREQ,
-	GET_MAXL,
-};
-
+#define GET_FREQ (GET_MAXL + 1)
 /**
  * get_property - fetch a property of interest for a give cpu.
  * @cpu: cpu for which the property is required
@@ -207,15 +202,37 @@ static int get_property(unsigned int cpu, unsigned long input,
 		/* now we have a valid frequency entry */
 		freq = table[i].frequency;
 
-		if (property == GET_LEVEL && (unsigned int)input == freq) {
+		if (property == GET_LEVEL_EXACT &&
+					(unsigned int)input == freq) {
 			/* get level by frequency */
 			*output = descend ? j : (max_level - j);
 			return 0;
-		}
-		if (property == GET_FREQ && level == j) {
+		} else if (property == GET_FREQ && level == j) {
 			/* get frequency by level */
 			*output = freq;
 			return 0;
+		} else if (property == GET_LEVEL_FLOOR) {
+			/* get minimum possible level by frequency */
+			if (descend && freq <= input) {
+				*output = j;
+				return 0;
+			} else if (!descend) {
+				if (freq <= input)
+					*output = (max_level - j);
+				else
+					return 0;
+			}
+		} else if (property == GET_LEVEL_CEIL) {
+			/* get maximum possible level by frequency */
+			if (!descend && freq >= input) {
+				*output = (max_level - j);
+				return 0;
+			} else if (descend) {
+				if (freq >= input)
+					*output = j;
+				else
+					return 0;
+			}
 		}
 		j++;
 	}
@@ -227,6 +244,8 @@ static int get_property(unsigned int cpu, unsigned long input,
  * cpufreq_cooling_get_level - for a give cpu, return the cooling level.
  * @cpu: cpu for which the level is required
  * @freq: the frequency of interest
+ * @property: can be GET_LEVEL_CEIL, GET_LEVEL_FLOOR, GET_LEVEL_EXACT or
+ * GET_MAXL
  *
  * This function will match the cooling level corresponding to the
  * requested @freq and return it.
@@ -234,11 +253,12 @@ static int get_property(unsigned int cpu, unsigned long input,
  * Return: The matched cooling level on success or THERMAL_CSTATE_INVALID
  * otherwise.
  */
-unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq)
+unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq,
+			enum cpufreq_cooling_property property)
 {
 	unsigned int val;
 
-	if (get_property(cpu, (unsigned long)freq, &val, GET_LEVEL))
+	if (get_property(cpu, (unsigned long)freq, &val, property))
 		return THERMAL_CSTATE_INVALID;
 
 	return (unsigned long)val;
diff --git a/drivers/thermal/samsung/exynos_thermal_common.c b/drivers/thermal/samsung/exynos_thermal_common.c
index a7306fa..aa4696b 100644
--- a/drivers/thermal/samsung/exynos_thermal_common.c
+++ b/drivers/thermal/samsung/exynos_thermal_common.c
@@ -156,7 +156,8 @@ static int exynos_bind(struct thermal_zone_device *thermal,
 	/* Bind the thermal zone to the cpufreq cooling device */
 	for (i = 0; i < tab_size; i++) {
 		clip_data = (struct freq_clip_table *)&(tab_ptr[i]);
-		level = cpufreq_cooling_get_level(0, clip_data->freq_clip_max);
+		level = cpufreq_cooling_get_level(0, clip_data->freq_clip_max,
+						GET_LEVEL_EXACT);
 		if (level == THERMAL_CSTATE_INVALID)
 			return 0;
 		switch (GET_ZONE(i)) {
diff --git a/include/linux/cpu_cooling.h b/include/linux/cpu_cooling.h
index f786935..f4d2b0e 100644
--- a/include/linux/cpu_cooling.h
+++ b/include/linux/cpu_cooling.h
@@ -44,6 +44,13 @@ struct cpufreq_cooling_status {
 	void *devdata;
 };
 
+enum cpufreq_cooling_property {
+	GET_LEVEL_CEIL,
+	GET_LEVEL_FLOOR,
+	GET_LEVEL_EXACT,
+	GET_MAXL,
+};
+
 #ifdef CONFIG_CPU_THERMAL
 /**
  * cpufreq_cooling_register - function to create cpufreq cooling device.
@@ -77,7 +84,21 @@ of_cpufreq_cooling_register(struct device_node *np,
  */
 void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev);
 
-unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq);
+/**
+ * cpufreq_cooling_get_level - for a give cpu, return the cooling level.
+ * @cpu: cpu for which the level is required
+ * @freq: the frequency of interest
+ * @property: can be GET_LEVEL_CEIL, GET_LEVEL_FLOOR, GET_LEVEL_EXACT or
+ * GET_MAXL
+ *
+ * This function will match the cooling level corresponding to the
+ * requested @freq and return it.
+ *
+ * Return: The matched cooling level on success or THERMAL_CSTATE_INVALID
+ * otherwise.
+ */
+unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq,
+					enum cpufreq_cooling_property);
 
 /**
  * cpufreq_cooling_register_notifier - register a driver with cpufreq cooling.
-- 
1.7.1