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-rw-r--r--Documentation/devicetree/bindings/misc/therm_est.txt90
-rw-r--r--drivers/misc/therm_fan_est.c152
-rw-r--r--include/linux/therm_est.h2
3 files changed, 225 insertions, 19 deletions
diff --git a/Documentation/devicetree/bindings/misc/therm_est.txt b/Documentation/devicetree/bindings/misc/therm_est.txt
index 0dbcb147a..0538981a7 100644
--- a/Documentation/devicetree/bindings/misc/therm_est.txt
+++ b/Documentation/devicetree/bindings/misc/therm_est.txt
@@ -6,6 +6,8 @@ Properties :
6 - tc1 : Coefficient 1 for thermal trend calculation. 6 - tc1 : Coefficient 1 for thermal trend calculation.
7 - tc2 : Coefficient 2 for thermal trend calculation. 7 - tc2 : Coefficient 2 for thermal trend calculation.
8 - node for subdev : Node for subdevice information. Required. 8 - node for subdev : Node for subdevice information. Required.
9 - use_tmargin : if tmargin algorithm should be used for calculating the
10 effective temp. Refer Tmargin section for more info.
9 11
10Properties in subdev node : Required. 12Properties in subdev node : Required.
11 - subdev_names : list of strings. It contains list of the name of the therm 13 - subdev_names : list of strings. It contains list of the name of the therm
@@ -45,3 +47,91 @@ Example:
45 }; 47 };
46 }; 48 };
47 }; 49 };
50
51Tmargin Algorithm:
52The native max temp algorithm lacks support for accomodating multiple thermal
53fan curves. Tmargin algorithm solves this by calculating the effective
54temperature as a difference from critical temperature of the therm fan est
55group. This allows us to take a union of two fan curves and satisfy the needs
56of both the therm-fan-est groups.
57The algorithm use the effective temperature(crit_temp - sensor_reading) to
58drive the cooling device.
59
60Properties rules for therm-fan-est dt entry:
61 - use_tmargin : To use the tmargin feature.
62 - profiles : New profile tmargin should be defined and chosen as default.
63 * The trip temperatures need to be given only in ascending order for the
64 thermal framework to register therm-fan-est zone. Hence, the dt values
65 for active trip temps should be given in ascending values of tmargin
66 values.
67 * Hysterysis is used only in cooling scenario. Since tmargin is
68 considered as a diff wrt crit_Temp, hysterysis values should be taken
69 as -ve values.
70
71Properties rules for fan dt entry:
72 - profiles : New profile for tmargin should be defined and chosen as default.
73 * The trip temps are considered in a ascending order of tmargin temps.
74 Hence, the pwm values should be considered in a descending order of
75 pwms.
76 * active_steps - The tmargin trip values are considered in the ascending
77 order(hence actual trip temps will be in descending order), so the
78 pwm mapping should be in the reverse order starting from 255 for
79 index 0.
80
81Example :
82
83 thermal-fan-est {
84 compatible = "thermal-fan-est";
85 name = "thermal-fan-est";
86 status = "okay";
87 num_resources = <0>;
88 shared_data = <&thermal_fan_est_shared_data>;
89 trip_length = <10>;
90 use_tmargin;
91
92 profiles {
93 default = "tmargin";
94 quiet {
95 active_trip_temps = <0 50000 63000 72000 81000
96 140000 150000 160000 170000 180000>;
97 active_hysteresis = <0 18000 8000 8000 8000
98 0 0 0 0 0>;
99 };
100 cool {
101 active_trip_temps = <0 35000 53000 62000 73000
102 140000 150000 160000 170000 180000>;
103 active_hysteresis = <0 9000 8000 8000 9000
104 0 0 0 0 0>;
105 };
106 tmargin {
107 active_trip_temps = <0 10000 15000 25000 35000
108 45000 55000 65000 75000 105000>;
109 active_hysteresis = <0 0 0 0 (-3000)
110 (-4000) (-4000) 0 0 0>;
111 };
112 };
113 };
114
115 pwm-fan {
116 compatible = "pwm-fan";
117 status = "okay";
118 #pwm-cells = <1>;
119 pwms = <&tegra_pwm4 0 45334>;
120 shared_data = <&pwm_fan_shared_data>;
121 profiles {
122 default = "tmargin";
123 quiet {
124 state_cap = <8>;
125 active_pwm = <0 60 90 120 150 180 210 240 255 255>;
126 };
127 cool {
128 state_cap = <4>;
129 active_pwm = <0 77 120 160 255 255 255 255 255 255>;
130 };
131 tmargin {
132 state_cap = <0>;
133 active_pwm = <255 255 240 210 180 150 120 90 60 0>;
134 };
135 };
136 };
137
diff --git a/drivers/misc/therm_fan_est.c b/drivers/misc/therm_fan_est.c
index f07a31009..e37c1130d 100644
--- a/drivers/misc/therm_fan_est.c
+++ b/drivers/misc/therm_fan_est.c
@@ -52,7 +52,8 @@ static void therm_fan_est_work_func(struct work_struct *work)
52{ 52{
53 int i, j, group, index, trip_index = 0; 53 int i, j, group, index, trip_index = 0;
54 int sum[MAX_SUBDEVICE_GROUP] = {0, }; 54 int sum[MAX_SUBDEVICE_GROUP] = {0, };
55 int sum_max = 0; 55 int sum_max = INT_MIN;
56 int sum_min = INT_MAX;
56 int temp = 0; 57 int temp = 0;
57 struct delayed_work *dwork = container_of(work, 58 struct delayed_work *dwork = container_of(work,
58 struct delayed_work, work); 59 struct delayed_work, work);
@@ -77,11 +78,21 @@ static void therm_fan_est_work_func(struct work_struct *work)
77 } 78 }
78 } 79 }
79 80
81 if (est->use_tmargin) {
82 for (i = 0; i < MAX_SUBDEVICE_GROUP; i++)
83 sum[i] = (est->crit_temp[i] * 100) - sum[i];
84 }
85
80#if !DEBUG 86#if !DEBUG
81 for (i = 0; i < MAX_SUBDEVICE_GROUP; i++) 87 for (i = 0; i < MAX_SUBDEVICE_GROUP; i++) {
88 sum_min = min(sum_min, sum[i]);
82 sum_max = max(sum_max, sum[i]); 89 sum_max = max(sum_max, sum[i]);
90 }
83 91
84 est->cur_temp = sum_max / 100 + est->toffset; 92 if (est->use_tmargin)
93 est->cur_temp = sum_min / 100 + est->toffset;
94 else
95 est->cur_temp = sum_max / 100 + est->toffset;
85#else 96#else
86 est->cur_temp = est->cur_temp_debug; 97 est->cur_temp = est->cur_temp_debug;
87#endif 98#endif
@@ -95,7 +106,9 @@ static void therm_fan_est_work_func(struct work_struct *work)
95 } 106 }
96 107
97 if (est->cur_temp != est->pre_temp) { 108 if (est->cur_temp != est->pre_temp) {
98 if (est->cur_temp > est->pre_temp) { 109 if (est->use_tmargin ?
110 (est->cur_temp < est->pre_temp) :
111 (est->cur_temp > est->pre_temp)) {
99 /* temperature is rising */ 112 /* temperature is rising */
100 read_lock(&est->state_lock); 113 read_lock(&est->state_lock);
101 for (trip_index = 0; 114 for (trip_index = 0;
@@ -105,10 +118,16 @@ static void therm_fan_est_work_func(struct work_struct *work)
105 } 118 }
106 read_unlock(&est->state_lock); 119 read_unlock(&est->state_lock);
107 120
108 if (est->current_trip_level < trip_index 121 if (est->use_tmargin) {
109 && est->current_trip_level != (trip_index - 1)) 122 if (est->current_trip_level >= trip_index
110 update_flag = true; 123 && est->current_trip_level != (trip_index - 1))
111 } else if (est->cur_temp < est->pre_temp) { 124 update_flag = true;
125 } else {
126 if (est->current_trip_level < trip_index
127 && est->current_trip_level != (trip_index - 1))
128 update_flag = true;
129 }
130 } else {
112 /* temperature is cooling */ 131 /* temperature is cooling */
113 read_lock(&est->state_lock); 132 read_lock(&est->state_lock);
114 for (trip_index = 1; 133 for (trip_index = 1;
@@ -119,10 +138,16 @@ static void therm_fan_est_work_func(struct work_struct *work)
119 } 138 }
120 read_unlock(&est->state_lock); 139 read_unlock(&est->state_lock);
121 140
122 if (est->current_trip_level >= trip_index 141 if (est->use_tmargin) {
123 && est->current_trip_level != (trip_index - 1) 142 if (est->current_trip_level < trip_index
124 && trip_index != (MAX_ACTIVE_STATES + 1))</