aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/apm821xx/patches-5.15/010-hwmon-tc654-add-thermal_cooling-device.patch
blob: 74f8e38150f60ab13f9662325f5be16fa60613e6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
From 4d49367c5303e3ebd17502a45b74de280f6be539 Mon Sep 17 00:00:00 2001
From: Christian Lamparter <chunkeey@gmail.com>
Date: Sun, 13 Feb 2022 01:47:33 +0100
Subject: hwmon: (tc654) Add thermal_cooling device support

Adds thermal_cooling device support to the tc654/tc655
driver. This make it possible to integrate it into a
device-tree supported thermal-zone node as a
cooling device.

I have been using this patch as part of the Netgear WNDR4700
Centria NAS Router support within OpenWrt since 2016.

Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Link: https://lore.kernel.org/r/20220213004733.2421193-1-chunkeey@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
--- a/drivers/hwmon/tc654.c
+++ b/drivers/hwmon/tc654.c
@@ -15,6 +15,7 @@
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
+#include <linux/thermal.h>
 #include <linux/util_macros.h>
 
 enum tc654_regs {
@@ -379,28 +380,20 @@ static ssize_t pwm_show(struct device *d
 	return sprintf(buf, "%d\n", pwm);
 }
 
-static ssize_t pwm_store(struct device *dev, struct device_attribute *da,
-			 const char *buf, size_t count)
+static int _set_pwm(struct tc654_data *data, unsigned long val)
 {
-	struct tc654_data *data = dev_get_drvdata(dev);
 	struct i2c_client *client = data->client;
-	unsigned long val;
 	int ret;
 
-	if (kstrtoul(buf, 10, &val))
-		return -EINVAL;
-	if (val > 255)
-		return -EINVAL;
-
 	mutex_lock(&data->update_lock);
 
-	if (val == 0)
+	if (val == 0) {
 		data->config |= TC654_REG_CONFIG_SDM;
-	else
+		data->duty_cycle = 0;
+	} else {
 		data->config &= ~TC654_REG_CONFIG_SDM;
-
-	data->duty_cycle = find_closest(val, tc654_pwm_map,
-					ARRAY_SIZE(tc654_pwm_map));
+		data->duty_cycle = val - 1;
+	}
 
 	ret = i2c_smbus_write_byte_data(client, TC654_REG_CONFIG, data->config);
 	if (ret < 0)
@@ -411,6 +404,24 @@ static ssize_t pwm_store(struct device *
 
 out:
 	mutex_unlock(&data->update_lock);
+	return ret;
+}
+
+static ssize_t pwm_store(struct device *dev, struct device_attribute *da,
+			 const char *buf, size_t count)
+{
+	struct tc654_data *data = dev_get_drvdata(dev);
+	unsigned long val;
+	int ret;
+
+	if (kstrtoul(buf, 10, &val))
+		return -EINVAL;
+	if (val > 255)
+		return -EINVAL;
+	if (val > 0)
+		val = find_closest(val, tc654_pwm_map, ARRAY_SIZE(tc654_pwm_map)) + 1;
+
+	ret = _set_pwm(data, val);
 	return ret < 0 ? ret : count;
 }
 
@@ -443,6 +454,58 @@ static struct attribute *tc654_attrs[] =
 ATTRIBUTE_GROUPS(tc654);
 
 /*
+ * thermal cooling device functions
+ *
+ * Account for the "ShutDown Mode (SDM)" state by offsetting
+ * the 16 PWM duty cycle states by 1.
+ *
+ * State  0 =   0% PWM | Shutdown - Fan(s) are off
+ * State  1 =  30% PWM | duty_cycle =  0
+ * State  2 = ~35% PWM | duty_cycle =  1
+ * [...]
+ * State 15 = ~95% PWM | duty_cycle = 14
+ * State 16 = 100% PWM | duty_cycle = 15
+ */
+#define TC654_MAX_COOLING_STATE	16
+
+static int tc654_get_max_state(struct thermal_cooling_device *cdev, unsigned long *state)
+{
+	*state = TC654_MAX_COOLING_STATE;
+	return 0;
+}
+
+static int tc654_get_cur_state(struct thermal_cooling_device *cdev, unsigned long *state)
+{
+	struct tc654_data *data = tc654_update_client(cdev->devdata);
+
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	if (data->config & TC654_REG_CONFIG_SDM)
+		*state = 0;	/* FAN is off */
+	else
+		*state = data->duty_cycle + 1;	/* offset PWM States by 1 */
+
+	return 0;
+}
+
+static int tc654_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
+{
+	struct tc654_data *data = tc654_update_client(cdev->devdata);
+
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	return _set_pwm(data, clamp_val(state, 0, TC654_MAX_COOLING_STATE));
+}
+
+static const struct thermal_cooling_device_ops tc654_fan_cool_ops = {
+	.get_max_state = tc654_get_max_state,
+	.get_cur_state = tc654_get_cur_state,
+	.set_cur_state = tc654_set_cur_state,
+};
+
+/*
  * device probe and removal
  */
 
@@ -472,7 +535,18 @@ static int tc654_probe(struct i2c_client
 	hwmon_dev =
 	    devm_hwmon_device_register_with_groups(dev, client->name, data,
 						   tc654_groups);
-	return PTR_ERR_OR_ZERO(hwmon_dev);
+	if (IS_ERR(hwmon_dev))
+		return PTR_ERR(hwmon_dev);
+
+	if (IS_ENABLED(CONFIG_THERMAL)) {
+		struct thermal_cooling_device *cdev;
+
+		cdev = devm_thermal_of_cooling_device_register(dev, dev->of_node, client->name,
+							       hwmon_dev, &tc654_fan_cool_ops);
+		return PTR_ERR_OR_ZERO(cdev);
+	}
+
+	return 0;
 }
 
 static const struct i2c_device_id tc654_id[] = {