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/sections.h> 22 #include <asm/pmac_low_i2c.h> 23 24 #include "windfarm.h" 25 26 #define VERSION "0.2" 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 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 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 struct wf_sensor_ops wf_lm75_ops = { 86 .get_value = wf_lm75_get, 87 .release = wf_lm75_release, 88 .owner = THIS_MODULE, 89 }; 90 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; 96 97 lm = kzalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL); 98 if (lm == NULL) 99 return -ENODEV; 100 101 lm->inited = 0; 102 lm->ds1775 = id->driver_data; 103 lm->i2c = client; 104 lm->sens.name = client->dev.platform_data; 105 lm->sens.ops = &wf_lm75_ops; 106 i2c_set_clientdata(client, lm); 107 108 rc = wf_register_sensor(&lm->sens); 109 if (rc) 110 kfree(lm); 111 112 return rc; 113 } 114 115 static struct i2c_driver wf_lm75_driver; 116 117 static struct i2c_client *wf_lm75_create(struct i2c_adapter *adapter, 118 u8 addr, int ds1775, 119 const char *loc) 120 { 121 struct i2c_board_info info; 122 struct i2c_client *client; 123 char *name; 124 125 DBG("wf_lm75: creating %s device at address 0x%02x\n", 126 ds1775 ? "ds1775" : "lm75", addr); 127 128 /* Usual rant about sensor names not beeing very consistent in 129 * the device-tree, oh well ... 130 * Add more entries below as you deal with more setups 131 */ 132 if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY")) 133 name = "hd-temp"; 134 else if (!strcmp(loc, "Incoming Air Temp")) 135 name = "incoming-air-temp"; 136 else if (!strcmp(loc, "ODD Temp")) 137 name = "optical-drive-temp"; 138 else if (!strcmp(loc, "HD Temp")) 139 name = "hard-drive-temp"; 140 else 141 goto fail; 142 143 memset(&info, 0, sizeof(struct i2c_board_info)); 144 info.addr = (addr >> 1) & 0x7f; 145 info.platform_data = name; 146 strlcpy(info.type, ds1775 ? "wf_ds1775" : "wf_lm75", I2C_NAME_SIZE); 147 148 client = i2c_new_device(adapter, &info); 149 if (client == NULL) { 150 printk(KERN_ERR "windfarm: failed to attach %s %s to i2c\n", 151 ds1775 ? "ds1775" : "lm75", name); 152 goto fail; 153 } 154 155 /* 156 * Let i2c-core delete that device on driver removal. 157 * This is safe because i2c-core holds the core_lock mutex for us. 158 */ 159 list_add_tail(&client->detected, &wf_lm75_driver.clients); 160 return client; 161 fail: 162 return NULL; 163 } 164 165 static int wf_lm75_attach(struct i2c_adapter *adapter) 166 { 167 struct device_node *busnode, *dev; 168 struct pmac_i2c_bus *bus; 169 170 DBG("wf_lm75: adapter %s detected\n", adapter->name); 171 172 bus = pmac_i2c_adapter_to_bus(adapter); 173 if (bus == NULL) 174 return -ENODEV; 175 busnode = pmac_i2c_get_bus_node(bus); 176 177 DBG("wf_lm75: bus found, looking for device...\n"); 178 179 /* Now look for lm75(s) in there */ 180 for (dev = NULL; 181 (dev = of_get_next_child(busnode, dev)) != NULL;) { 182 const char *loc = 183 of_get_property(dev, "hwsensor-location", NULL); 184 u8 addr; 185 186 /* We must re-match the adapter in order to properly check 187 * the channel on multibus setups 188 */ 189 if (!pmac_i2c_match_adapter(dev, adapter)) 190 continue; 191 addr = pmac_i2c_get_dev_addr(dev); 192 if (loc == NULL || addr == 0) 193 continue; 194 /* real lm75 */ 195 if (of_device_is_compatible(dev, "lm75")) 196 wf_lm75_create(adapter, addr, 0, loc); 197 /* ds1775 (compatible, better resolution */ 198 else if (of_device_is_compatible(dev, "ds1775")) 199 wf_lm75_create(adapter, addr, 1, loc); 200 } 201 return 0; 202 } 203 204 static int wf_lm75_remove(struct i2c_client *client) 205 { 206 struct wf_lm75_sensor *lm = i2c_get_clientdata(client); 207 208 DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name); 209 210 /* Mark client detached */ 211 lm->i2c = NULL; 212 213 /* release sensor */ 214 wf_unregister_sensor(&lm->sens); 215 216 return 0; 217 } 218 219 static const struct i2c_device_id wf_lm75_id[] = { 220 { "wf_lm75", 0 }, 221 { "wf_ds1775", 1 }, 222 { } 223 }; 224 225 static struct i2c_driver wf_lm75_driver = { 226 .driver = { 227 .name = "wf_lm75", 228 }, 229 .attach_adapter = wf_lm75_attach, 230 .probe = wf_lm75_probe, 231 .remove = wf_lm75_remove, 232 .id_table = wf_lm75_id, 233 }; 234 235 static int __init wf_lm75_sensor_init(void) 236 { 237 /* Don't register on old machines that use therm_pm72 for now */ 238 if (of_machine_is_compatible("PowerMac7,2") || 239 of_machine_is_compatible("PowerMac7,3") || 240 of_machine_is_compatible("RackMac3,1")) 241 return -ENODEV; 242 return i2c_add_driver(&wf_lm75_driver); 243 } 244 245 static void __exit wf_lm75_sensor_exit(void) 246 { 247 i2c_del_driver(&wf_lm75_driver); 248 } 249 250 251 module_init(wf_lm75_sensor_init); 252 module_exit(wf_lm75_sensor_exit); 253 254 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); 255 MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control"); 256 MODULE_LICENSE("GPL"); 257 258