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.h>
18#include <asm/machdep.h>
19#include <asm/io.h>
20#include <asm/sections.h>
21#include <asm/pmac_low_i2c.h>
22
23#include "windfarm.h"
24
25#define VERSION "1.0"
26
27#undef DEBUG
28
29#ifdef DEBUG
30#define DBG(args...)	printk(args)
31#else
32#define DBG(args...)	do { } while(0)
33#endif
34
35struct wf_lm75_sensor {
36	unsigned int		ds1775 : 1;
37	unsigned int		inited : 1;
38	struct i2c_client	*i2c;
39	struct wf_sensor	sens;
40};
41#define wf_to_lm75(c) container_of(c, struct wf_lm75_sensor, sens)
42
43static int wf_lm75_get(struct wf_sensor *sr, s32 *value)
44{
45	struct wf_lm75_sensor *lm = wf_to_lm75(sr);
46	s32 data;
47
48	if (lm->i2c == NULL)
49		return -ENODEV;
50
51	/* Init chip if necessary */
52	if (!lm->inited) {
53		u8 cfg_new, cfg = (u8)i2c_smbus_read_byte_data(lm->i2c, 1);
54
55		DBG("wf_lm75: Initializing %s, cfg was: %02x\n",
56		    sr->name, cfg);
57
58		/* clear shutdown bit, keep other settings as left by
59		 * the firmware for now
60		 */
61		cfg_new = cfg & ~0x01;
62		i2c_smbus_write_byte_data(lm->i2c, 1, cfg_new);
63		lm->inited = 1;
64
65		/* If we just powered it up, let's wait 200 ms */
66		msleep(200);
67	}
68
69	/* Read temperature register */
70	data = (s32)le16_to_cpu(i2c_smbus_read_word_data(lm->i2c, 0));
71	data <<= 8;
72	*value = data;
73
74	return 0;
75}
76
77static void wf_lm75_release(struct wf_sensor *sr)
78{
79	struct wf_lm75_sensor *lm = wf_to_lm75(sr);
80
81	kfree(lm);
82}
83
84static const struct wf_sensor_ops wf_lm75_ops = {
85	.get_value	= wf_lm75_get,
86	.release	= wf_lm75_release,
87	.owner		= THIS_MODULE,
88};
89
90static int wf_lm75_probe(struct i2c_client *client)
91{
92	const struct i2c_device_id *id = i2c_client_get_device_id(client);
93	struct wf_lm75_sensor *lm;
94	int rc, ds1775;
95	const char *name, *loc;
96
97	if (id)
98		ds1775 = id->driver_data;
99	else
100		ds1775 = !!of_device_get_match_data(&client->dev);
101
102	DBG("wf_lm75: creating  %s device at address 0x%02x\n",
103	    ds1775 ? "ds1775" : "lm75", client->addr);
104
105	loc = of_get_property(client->dev.of_node, "hwsensor-location", NULL);
106	if (!loc) {
107		dev_warn(&client->dev, "Missing hwsensor-location property!\n");
108		return -ENXIO;
109	}
110
111	/* Usual rant about sensor names not beeing very consistent in
112	 * the device-tree, oh well ...
113	 * Add more entries below as you deal with more setups
114	 */
115	if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY"))
116		name = "hd-temp";
117	else if (!strcmp(loc, "Incoming Air Temp"))
118		name = "incoming-air-temp";
119	else if (!strcmp(loc, "ODD Temp"))
120		name = "optical-drive-temp";
121	else if (!strcmp(loc, "HD Temp"))
122		name = "hard-drive-temp";
123	else if (!strcmp(loc, "PCI SLOTS"))
124		name = "slots-temp";
125	else if (!strcmp(loc, "CPU A INLET"))
126		name = "cpu-inlet-temp-0";
127	else if (!strcmp(loc, "CPU B INLET"))
128		name = "cpu-inlet-temp-1";
129	else
130		return -ENXIO;
131
132
133	lm = kzalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL);
134	if (lm == NULL)
135		return -ENODEV;
136
137	lm->inited = 0;
138	lm->ds1775 = ds1775;
139	lm->i2c = client;
140	lm->sens.name = name;
141	lm->sens.ops = &wf_lm75_ops;
142	i2c_set_clientdata(client, lm);
143
144	rc = wf_register_sensor(&lm->sens);
145	if (rc)
146		kfree(lm);
147	return rc;
148}
149
150static void wf_lm75_remove(struct i2c_client *client)
151{
152	struct wf_lm75_sensor *lm = i2c_get_clientdata(client);
153
154	/* Mark client detached */
155	lm->i2c = NULL;
156
157	/* release sensor */
158	wf_unregister_sensor(&lm->sens);
159}
160
161static const struct i2c_device_id wf_lm75_id[] = {
162	{ "MAC,lm75", 0 },
163	{ "MAC,ds1775", 1 },
164	{ }
165};
166MODULE_DEVICE_TABLE(i2c, wf_lm75_id);
167
168static const struct of_device_id wf_lm75_of_id[] = {
169	{ .compatible = "lm75", .data = (void *)0},
170	{ .compatible = "ds1775", .data = (void *)1 },
171	{ }
172};
173MODULE_DEVICE_TABLE(of, wf_lm75_of_id);
174
175static struct i2c_driver wf_lm75_driver = {
176	.driver = {
177		.name	= "wf_lm75",
178		.of_match_table = wf_lm75_of_id,
179	},
180	.probe		= wf_lm75_probe,
181	.remove		= wf_lm75_remove,
182	.id_table	= wf_lm75_id,
183};
184
185module_i2c_driver(wf_lm75_driver);
186
187MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
188MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
189MODULE_LICENSE("GPL");
190
191