1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Windfarm PowerMac thermal control. LM75 sensor
4  *
5  * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
6  *                    <benh@kernel.crashing.org>
7  */
8 
9 #include <linux/types.h>
10 #include <linux/errno.h>
11 #include <linux/kernel.h>
12 #include <linux/delay.h>
13 #include <linux/slab.h>
14 #include <linux/init.h>
15 #include <linux/wait.h>
16 #include <linux/i2c.h>
17 #include <linux/of_device.h>
18 #include <asm/prom.h>
19 #include <asm/machdep.h>
20 #include <asm/io.h>
21 #include <asm/sections.h>
22 #include <asm/pmac_low_i2c.h>
23 
24 #include "windfarm.h"
25 
26 #define VERSION "1.0"
27 
28 #undef DEBUG
29 
30 #ifdef DEBUG
31 #define DBG(args...)	printk(args)
32 #else
33 #define DBG(args...)	do { } while(0)
34 #endif
35 
36 struct wf_lm75_sensor {
37 	int			ds1775 : 1;
38 	int			inited : 1;
39 	struct i2c_client	*i2c;
40 	struct wf_sensor	sens;
41 };
42 #define wf_to_lm75(c) container_of(c, struct wf_lm75_sensor, sens)
43 
wf_lm75_get(struct wf_sensor * sr,s32 * value)44 static int wf_lm75_get(struct wf_sensor *sr, s32 *value)
45 {
46 	struct wf_lm75_sensor *lm = wf_to_lm75(sr);
47 	s32 data;
48 
49 	if (lm->i2c == NULL)
50 		return -ENODEV;
51 
52 	/* Init chip if necessary */
53 	if (!lm->inited) {
54 		u8 cfg_new, cfg = (u8)i2c_smbus_read_byte_data(lm->i2c, 1);
55 
56 		DBG("wf_lm75: Initializing %s, cfg was: %02x\n",
57 		    sr->name, cfg);
58 
59 		/* clear shutdown bit, keep other settings as left by
60 		 * the firmware for now
61 		 */
62 		cfg_new = cfg & ~0x01;
63 		i2c_smbus_write_byte_data(lm->i2c, 1, cfg_new);
64 		lm->inited = 1;
65 
66 		/* If we just powered it up, let's wait 200 ms */
67 		msleep(200);
68 	}
69 
70 	/* Read temperature register */
71 	data = (s32)le16_to_cpu(i2c_smbus_read_word_data(lm->i2c, 0));
72 	data <<= 8;
73 	*value = data;
74 
75 	return 0;
76 }
77 
wf_lm75_release(struct wf_sensor * sr)78 static void wf_lm75_release(struct wf_sensor *sr)
79 {
80 	struct wf_lm75_sensor *lm = wf_to_lm75(sr);
81 
82 	kfree(lm);
83 }
84 
85 static const struct wf_sensor_ops wf_lm75_ops = {
86 	.get_value	= wf_lm75_get,
87 	.release	= wf_lm75_release,
88 	.owner		= THIS_MODULE,
89 };
90 
wf_lm75_probe(struct i2c_client * client,const struct i2c_device_id * id)91 static int wf_lm75_probe(struct i2c_client *client,
92 			 const struct i2c_device_id *id)
93 {
94 	struct wf_lm75_sensor *lm;
95 	int rc, ds1775;
96 	const char *name, *loc;
97 
98 	if (id)
99 		ds1775 = id->driver_data;
100 	else
101 		ds1775 = !!of_device_get_match_data(&client->dev);
102 
103 	DBG("wf_lm75: creating  %s device at address 0x%02x\n",
104 	    ds1775 ? "ds1775" : "lm75", client->addr);
105 
106 	loc = of_get_property(client->dev.of_node, "hwsensor-location", NULL);
107 	if (!loc) {
108 		dev_warn(&client->dev, "Missing hwsensor-location property!\n");
109 		return -ENXIO;
110 	}
111 
112 	/* Usual rant about sensor names not beeing very consistent in
113 	 * the device-tree, oh well ...
114 	 * Add more entries below as you deal with more setups
115 	 */
116 	if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY"))
117 		name = "hd-temp";
118 	else if (!strcmp(loc, "Incoming Air Temp"))
119 		name = "incoming-air-temp";
120 	else if (!strcmp(loc, "ODD Temp"))
121 		name = "optical-drive-temp";
122 	else if (!strcmp(loc, "HD Temp"))
123 		name = "hard-drive-temp";
124 	else if (!strcmp(loc, "PCI SLOTS"))
125 		name = "slots-temp";
126 	else if (!strcmp(loc, "CPU A INLET"))
127 		name = "cpu-inlet-temp-0";
128 	else if (!strcmp(loc, "CPU B INLET"))
129 		name = "cpu-inlet-temp-1";
130 	else
131 		return -ENXIO;
132 
133 
134 	lm = kzalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL);
135 	if (lm == NULL)
136 		return -ENODEV;
137 
138 	lm->inited = 0;
139 	lm->ds1775 = ds1775;
140 	lm->i2c = client;
141 	lm->sens.name = name;
142 	lm->sens.ops = &wf_lm75_ops;
143 	i2c_set_clientdata(client, lm);
144 
145 	rc = wf_register_sensor(&lm->sens);
146 	if (rc)
147 		kfree(lm);
148 	return rc;
149 }
150 
wf_lm75_remove(struct i2c_client * client)151 static int wf_lm75_remove(struct i2c_client *client)
152 {
153 	struct wf_lm75_sensor *lm = i2c_get_clientdata(client);
154 
155 	/* Mark client detached */
156 	lm->i2c = NULL;
157 
158 	/* release sensor */
159 	wf_unregister_sensor(&lm->sens);
160 
161 	return 0;
162 }
163 
164 static const struct i2c_device_id wf_lm75_id[] = {
165 	{ "MAC,lm75", 0 },
166 	{ "MAC,ds1775", 1 },
167 	{ }
168 };
169 MODULE_DEVICE_TABLE(i2c, wf_lm75_id);
170 
171 static const struct of_device_id wf_lm75_of_id[] = {
172 	{ .compatible = "lm75", .data = (void *)0},
173 	{ .compatible = "ds1775", .data = (void *)1 },
174 	{ }
175 };
176 MODULE_DEVICE_TABLE(of, wf_lm75_of_id);
177 
178 static struct i2c_driver wf_lm75_driver = {
179 	.driver = {
180 		.name	= "wf_lm75",
181 		.of_match_table = wf_lm75_of_id,
182 	},
183 	.probe		= wf_lm75_probe,
184 	.remove		= wf_lm75_remove,
185 	.id_table	= wf_lm75_id,
186 };
187 
188 module_i2c_driver(wf_lm75_driver);
189 
190 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
191 MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
192 MODULE_LICENSE("GPL");
193 
194