1 /* 2 * Windfarm PowerMac thermal control. LM75 sensor 3 * 4 * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp. 5 * <benh@kernel.crashing.org> 6 * 7 * Released under the term of the GNU GPL v2. 8 */ 9 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 <asm/prom.h> 19 #include <asm/machdep.h> 20 #include <asm/io.h> 21 #include <asm/system.h> 22 #include <asm/sections.h> 23 #include <asm/pmac_low_i2c.h> 24 25 #include "windfarm.h" 26 27 #define VERSION "0.2" 28 29 #undef DEBUG 30 31 #ifdef DEBUG 32 #define DBG(args...) printk(args) 33 #else 34 #define DBG(args...) do { } while(0) 35 #endif 36 37 struct wf_lm75_sensor { 38 int ds1775 : 1; 39 int inited : 1; 40 struct i2c_client *i2c; 41 struct wf_sensor sens; 42 }; 43 #define wf_to_lm75(c) container_of(c, struct wf_lm75_sensor, sens) 44 45 static int wf_lm75_get(struct wf_sensor *sr, s32 *value) 46 { 47 struct wf_lm75_sensor *lm = wf_to_lm75(sr); 48 s32 data; 49 50 if (lm->i2c == NULL) 51 return -ENODEV; 52 53 /* Init chip if necessary */ 54 if (!lm->inited) { 55 u8 cfg_new, cfg = (u8)i2c_smbus_read_byte_data(lm->i2c, 1); 56 57 DBG("wf_lm75: Initializing %s, cfg was: %02x\n", 58 sr->name, cfg); 59 60 /* clear shutdown bit, keep other settings as left by 61 * the firmware for now 62 */ 63 cfg_new = cfg & ~0x01; 64 i2c_smbus_write_byte_data(lm->i2c, 1, cfg_new); 65 lm->inited = 1; 66 67 /* If we just powered it up, let's wait 200 ms */ 68 msleep(200); 69 } 70 71 /* Read temperature register */ 72 data = (s32)le16_to_cpu(i2c_smbus_read_word_data(lm->i2c, 0)); 73 data <<= 8; 74 *value = data; 75 76 return 0; 77 } 78 79 static void wf_lm75_release(struct wf_sensor *sr) 80 { 81 struct wf_lm75_sensor *lm = wf_to_lm75(sr); 82 83 kfree(lm); 84 } 85 86 static struct wf_sensor_ops wf_lm75_ops = { 87 .get_value = wf_lm75_get, 88 .release = wf_lm75_release, 89 .owner = THIS_MODULE, 90 }; 91 92 static int wf_lm75_probe(struct i2c_client *client, 93 const struct i2c_device_id *id) 94 { 95 struct wf_lm75_sensor *lm; 96 int rc; 97 98 lm = kzalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL); 99 if (lm == NULL) 100 return -ENODEV; 101 102 lm->inited = 0; 103 lm->ds1775 = id->driver_data; 104 lm->i2c = client; 105 lm->sens.name = client->dev.platform_data; 106 lm->sens.ops = &wf_lm75_ops; 107 i2c_set_clientdata(client, lm); 108 109 rc = wf_register_sensor(&lm->sens); 110 if (rc) { 111 i2c_set_clientdata(client, NULL); 112 kfree(lm); 113 } 114 115 return rc; 116 } 117 118 static struct i2c_driver wf_lm75_driver; 119 120 static struct i2c_client *wf_lm75_create(struct i2c_adapter *adapter, 121 u8 addr, int ds1775, 122 const char *loc) 123 { 124 struct i2c_board_info info; 125 struct i2c_client *client; 126 char *name; 127 128 DBG("wf_lm75: creating %s device at address 0x%02x\n", 129 ds1775 ? "ds1775" : "lm75", addr); 130 131 /* Usual rant about sensor names not beeing very consistent in 132 * the device-tree, oh well ... 133 * Add more entries below as you deal with more setups 134 */ 135 if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY")) 136 name = "hd-temp"; 137 else if (!strcmp(loc, "Incoming Air Temp")) 138 name = "incoming-air-temp"; 139 else if (!strcmp(loc, "ODD Temp")) 140 name = "optical-drive-temp"; 141 else if (!strcmp(loc, "HD Temp")) 142 name = "hard-drive-temp"; 143 else 144 goto fail; 145 146 memset(&info, 0, sizeof(struct i2c_board_info)); 147 info.addr = (addr >> 1) & 0x7f; 148 info.platform_data = name; 149 strlcpy(info.type, ds1775 ? "wf_ds1775" : "wf_lm75", I2C_NAME_SIZE); 150 151 client = i2c_new_device(adapter, &info); 152 if (client == NULL) { 153 printk(KERN_ERR "windfarm: failed to attach %s %s to i2c\n", 154 ds1775 ? "ds1775" : "lm75", name); 155 goto fail; 156 } 157 158 /* 159 * Let i2c-core delete that device on driver removal. 160 * This is safe because i2c-core holds the core_lock mutex for us. 161 */ 162 list_add_tail(&client->detected, &wf_lm75_driver.clients); 163 return client; 164 fail: 165 return NULL; 166 } 167 168 static int wf_lm75_attach(struct i2c_adapter *adapter) 169 { 170 struct device_node *busnode, *dev; 171 struct pmac_i2c_bus *bus; 172 173 DBG("wf_lm75: adapter %s detected\n", adapter->name); 174 175 bus = pmac_i2c_adapter_to_bus(adapter); 176 if (bus == NULL) 177 return -ENODEV; 178 busnode = pmac_i2c_get_bus_node(bus); 179 180 DBG("wf_lm75: bus found, looking for device...\n"); 181 182 /* Now look for lm75(s) in there */ 183 for (dev = NULL; 184 (dev = of_get_next_child(busnode, dev)) != NULL;) { 185 const char *loc = 186 of_get_property(dev, "hwsensor-location", NULL); 187 u8 addr; 188 189 /* We must re-match the adapter in order to properly check 190 * the channel on multibus setups 191 */ 192 if (!pmac_i2c_match_adapter(dev, adapter)) 193 continue; 194 addr = pmac_i2c_get_dev_addr(dev); 195 if (loc == NULL || addr == 0) 196 continue; 197 /* real lm75 */ 198 if (of_device_is_compatible(dev, "lm75")) 199 wf_lm75_create(adapter, addr, 0, loc); 200 /* ds1775 (compatible, better resolution */ 201 else if (of_device_is_compatible(dev, "ds1775")) 202 wf_lm75_create(adapter, addr, 1, loc); 203 } 204 return 0; 205 } 206 207 static int wf_lm75_remove(struct i2c_client *client) 208 { 209 struct wf_lm75_sensor *lm = i2c_get_clientdata(client); 210 211 DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name); 212 213 /* Mark client detached */ 214 lm->i2c = NULL; 215 216 /* release sensor */ 217 wf_unregister_sensor(&lm->sens); 218 219 i2c_set_clientdata(client, NULL); 220 return 0; 221 } 222 223 static const struct i2c_device_id wf_lm75_id[] = { 224 { "wf_lm75", 0 }, 225 { "wf_ds1775", 1 }, 226 { } 227 }; 228 229 static struct i2c_driver wf_lm75_driver = { 230 .driver = { 231 .name = "wf_lm75", 232 }, 233 .attach_adapter = wf_lm75_attach, 234 .probe = wf_lm75_probe, 235 .remove = wf_lm75_remove, 236 .id_table = wf_lm75_id, 237 }; 238 239 static int __init wf_lm75_sensor_init(void) 240 { 241 /* Don't register on old machines that use therm_pm72 for now */ 242 if (machine_is_compatible("PowerMac7,2") || 243 machine_is_compatible("PowerMac7,3") || 244 machine_is_compatible("RackMac3,1")) 245 return -ENODEV; 246 return i2c_add_driver(&wf_lm75_driver); 247 } 248 249 static void __exit wf_lm75_sensor_exit(void) 250 { 251 i2c_del_driver(&wf_lm75_driver); 252 } 253 254 255 module_init(wf_lm75_sensor_init); 256 module_exit(wf_lm75_sensor_exit); 257 258 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); 259 MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control"); 260 MODULE_LICENSE("GPL"); 261 262