2 * Windfarm PowerMac thermal control. LM75 sensor
4 * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
5 * <benh@kernel.crashing.org>
7 * Released under the term of the GNU GPL v2.
10 #include <linux/types.h>
11 #include <linux/errno.h>
12 #include <linux/kernel.h>
13 #include <linux/delay.h>
14 #include <linux/slab.h>
15 #include <linux/init.h>
16 #include <linux/wait.h>
17 #include <linux/i2c.h>
18 #include <linux/i2c-dev.h>
20 #include <asm/machdep.h>
22 #include <asm/system.h>
23 #include <asm/sections.h>
24 #include <asm/pmac_low_i2c.h>
33 #define DBG(args...) printk(args)
35 #define DBG(args...) do { } while(0)
38 struct wf_lm75_sensor
{
41 struct i2c_client i2c
;
42 struct wf_sensor sens
;
44 #define wf_to_lm75(c) container_of(c, struct wf_lm75_sensor, sens)
45 #define i2c_to_lm75(c) container_of(c, struct wf_lm75_sensor, i2c)
47 static int wf_lm75_attach(struct i2c_adapter
*adapter
);
48 static int wf_lm75_detach(struct i2c_client
*client
);
50 static struct i2c_driver wf_lm75_driver
= {
54 .attach_adapter
= wf_lm75_attach
,
55 .detach_client
= wf_lm75_detach
,
58 static int wf_lm75_get(struct wf_sensor
*sr
, s32
*value
)
60 struct wf_lm75_sensor
*lm
= wf_to_lm75(sr
);
63 if (lm
->i2c
.adapter
== NULL
)
66 /* Init chip if necessary */
68 u8 cfg_new
, cfg
= (u8
)i2c_smbus_read_byte_data(&lm
->i2c
, 1);
70 DBG("wf_lm75: Initializing %s, cfg was: %02x\n",
73 /* clear shutdown bit, keep other settings as left by
74 * the firmware for now
76 cfg_new
= cfg
& ~0x01;
77 i2c_smbus_write_byte_data(&lm
->i2c
, 1, cfg_new
);
80 /* If we just powered it up, let's wait 200 ms */
84 /* Read temperature register */
85 data
= (s32
)le16_to_cpu(i2c_smbus_read_word_data(&lm
->i2c
, 0));
92 static void wf_lm75_release(struct wf_sensor
*sr
)
94 struct wf_lm75_sensor
*lm
= wf_to_lm75(sr
);
96 /* check if client is registered and detach from i2c */
97 if (lm
->i2c
.adapter
) {
98 i2c_detach_client(&lm
->i2c
);
99 lm
->i2c
.adapter
= NULL
;
105 static struct wf_sensor_ops wf_lm75_ops
= {
106 .get_value
= wf_lm75_get
,
107 .release
= wf_lm75_release
,
108 .owner
= THIS_MODULE
,
111 static struct wf_lm75_sensor
*wf_lm75_create(struct i2c_adapter
*adapter
,
115 struct wf_lm75_sensor
*lm
;
117 DBG("wf_lm75: creating %s device at address 0x%02x\n",
118 ds1775
? "ds1775" : "lm75", addr
);
120 lm
= kmalloc(sizeof(struct wf_lm75_sensor
), GFP_KERNEL
);
123 memset(lm
, 0, sizeof(struct wf_lm75_sensor
));
125 /* Usual rant about sensor names not beeing very consistent in
126 * the device-tree, oh well ...
127 * Add more entries below as you deal with more setups
129 if (!strcmp(loc
, "Hard drive") || !strcmp(loc
, "DRIVE BAY"))
130 lm
->sens
.name
= "hd-temp";
135 lm
->sens
.ops
= &wf_lm75_ops
;
137 lm
->i2c
.addr
= (addr
>> 1) & 0x7f;
138 lm
->i2c
.adapter
= adapter
;
139 lm
->i2c
.driver
= &wf_lm75_driver
;
140 strncpy(lm
->i2c
.name
, lm
->sens
.name
, I2C_NAME_SIZE
-1);
142 if (i2c_attach_client(&lm
->i2c
)) {
143 printk(KERN_ERR
"windfarm: failed to attach %s %s to i2c\n",
144 ds1775
? "ds1775" : "lm75", lm
->i2c
.name
);
148 if (wf_register_sensor(&lm
->sens
)) {
149 i2c_detach_client(&lm
->i2c
);
159 static int wf_lm75_attach(struct i2c_adapter
*adapter
)
161 struct device_node
*busnode
, *dev
;
162 struct pmac_i2c_bus
*bus
;
164 DBG("wf_lm75: adapter %s detected\n", adapter
->name
);
166 bus
= pmac_i2c_adapter_to_bus(adapter
);
169 busnode
= pmac_i2c_get_bus_node(bus
);
171 DBG("wf_lm75: bus found, looking for device...\n");
173 /* Now look for lm75(s) in there */
175 (dev
= of_get_next_child(busnode
, dev
)) != NULL
;) {
177 get_property(dev
, "hwsensor-location", NULL
);
178 u32
*reg
= (u32
*)get_property(dev
, "reg", NULL
);
179 DBG(" dev: %s... (loc: %p, reg: %p)\n", dev
->name
, loc
, reg
);
180 if (loc
== NULL
|| reg
== NULL
)
183 if (device_is_compatible(dev
, "lm75"))
184 wf_lm75_create(adapter
, *reg
, 0, loc
);
185 /* ds1775 (compatible, better resolution */
186 else if (device_is_compatible(dev
, "ds1775"))
187 wf_lm75_create(adapter
, *reg
, 1, loc
);
192 static int wf_lm75_detach(struct i2c_client
*client
)
194 struct wf_lm75_sensor
*lm
= i2c_to_lm75(client
);
196 DBG("wf_lm75: i2c detatch called for %s\n", lm
->sens
.name
);
198 /* Mark client detached */
199 lm
->i2c
.adapter
= NULL
;
202 wf_unregister_sensor(&lm
->sens
);
207 static int __init
wf_lm75_sensor_init(void)
209 return i2c_add_driver(&wf_lm75_driver
);
212 static void __exit
wf_lm75_sensor_exit(void)
214 i2c_del_driver(&wf_lm75_driver
);
218 module_init(wf_lm75_sensor_init
);
219 module_exit(wf_lm75_sensor_exit
);
221 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
222 MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
223 MODULE_LICENSE("GPL");