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>
32 #define DBG(args...) printk(args)
34 #define DBG(args...) do { } while(0)
37 struct wf_lm75_sensor {
40 struct i2c_client i2c;
41 struct wf_sensor sens;
43 #define wf_to_lm75(c) container_of(c, struct wf_lm75_sensor, sens)
44 #define i2c_to_lm75(c) container_of(c, struct wf_lm75_sensor, i2c)
46 static int wf_lm75_attach(struct i2c_adapter *adapter);
47 static int wf_lm75_detach(struct i2c_client *client);
49 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)
162 struct device_node *smu, *bus, *dev;
164 /* We currently only deal with LM75's hanging off the SMU
165 * i2c busses. If we extend that driver to other/older
166 * machines, we should split this function into SMU-i2c,
167 * keywest-i2c, PMU-i2c, ...
170 DBG("wf_lm75: adapter %s detected\n", adapter->name);
172 if (strncmp(adapter->name, "smu-i2c-", 8) != 0)
174 smu = of_find_node_by_type(NULL, "smu");
178 /* Look for the bus in the device-tree */
179 bus_id = (u8)simple_strtoul(adapter->name + 8, NULL, 16);
181 DBG("wf_lm75: bus ID is %x\n", bus_id);
183 /* Look for sensors subdir */
185 (bus = of_get_next_child(smu, bus)) != NULL;) {
188 if (strcmp(bus->name, "i2c"))
190 reg = (u32 *)get_property(bus, "reg", NULL);
198 printk(KERN_WARNING "windfarm: SMU i2c bus 0x%x not found"
199 " in device-tree !\n", bus_id);
203 DBG("wf_lm75: bus found, looking for device...\n");
205 /* Now look for lm75(s) in there */
207 (dev = of_get_next_child(bus, dev)) != NULL;) {
209 get_property(dev, "hwsensor-location", NULL);
210 u32 *reg = (u32 *)get_property(dev, "reg", NULL);
211 DBG(" dev: %s... (loc: %p, reg: %p)\n", dev->name, loc, reg);
212 if (loc == NULL || reg == NULL)
215 if (device_is_compatible(dev, "lm75"))
216 wf_lm75_create(adapter, *reg, 0, loc);
217 /* ds1775 (compatible, better resolution */
218 else if (device_is_compatible(dev, "ds1775"))
219 wf_lm75_create(adapter, *reg, 1, loc);
227 static int wf_lm75_detach(struct i2c_client *client)
229 struct wf_lm75_sensor *lm = i2c_to_lm75(client);
231 DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name);
233 /* Mark client detached */
234 lm->i2c.adapter = NULL;
237 wf_unregister_sensor(&lm->sens);
242 static int __init wf_lm75_sensor_init(void)
246 rc = i2c_add_driver(&wf_lm75_driver);
252 static void __exit wf_lm75_sensor_exit(void)
254 i2c_del_driver(&wf_lm75_driver);
258 module_init(wf_lm75_sensor_init);
259 module_exit(wf_lm75_sensor_exit);
261 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
262 MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
263 MODULE_LICENSE("GPL");