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 #define i2c_to_lm75(c) container_of(c, struct wf_lm75_sensor, i2c) 45 46 static int wf_lm75_attach(struct i2c_adapter *adapter); 47 static int wf_lm75_detach(struct i2c_client *client); 48 49 static struct i2c_driver wf_lm75_driver = { 50 .driver = { 51 .name = "wf_lm75", 52 }, 53 .attach_adapter = wf_lm75_attach, 54 .detach_client = wf_lm75_detach, 55 }; 56 57 static int wf_lm75_get(struct wf_sensor *sr, s32 *value) 58 { 59 struct wf_lm75_sensor *lm = wf_to_lm75(sr); 60 s32 data; 61 62 if (lm->i2c.adapter == NULL) 63 return -ENODEV; 64 65 /* Init chip if necessary */ 66 if (!lm->inited) { 67 u8 cfg_new, cfg = (u8)i2c_smbus_read_byte_data(&lm->i2c, 1); 68 69 DBG("wf_lm75: Initializing %s, cfg was: %02x\n", 70 sr->name, cfg); 71 72 /* clear shutdown bit, keep other settings as left by 73 * the firmware for now 74 */ 75 cfg_new = cfg & ~0x01; 76 i2c_smbus_write_byte_data(&lm->i2c, 1, cfg_new); 77 lm->inited = 1; 78 79 /* If we just powered it up, let's wait 200 ms */ 80 msleep(200); 81 } 82 83 /* Read temperature register */ 84 data = (s32)le16_to_cpu(i2c_smbus_read_word_data(&lm->i2c, 0)); 85 data <<= 8; 86 *value = data; 87 88 return 0; 89 } 90 91 static void wf_lm75_release(struct wf_sensor *sr) 92 { 93 struct wf_lm75_sensor *lm = wf_to_lm75(sr); 94 95 /* check if client is registered and detach from i2c */ 96 if (lm->i2c.adapter) { 97 i2c_detach_client(&lm->i2c); 98 lm->i2c.adapter = NULL; 99 } 100 101 kfree(lm); 102 } 103 104 static struct wf_sensor_ops wf_lm75_ops = { 105 .get_value = wf_lm75_get, 106 .release = wf_lm75_release, 107 .owner = THIS_MODULE, 108 }; 109 110 static struct wf_lm75_sensor *wf_lm75_create(struct i2c_adapter *adapter, 111 u8 addr, int ds1775, 112 const char *loc) 113 { 114 struct wf_lm75_sensor *lm; 115 int rc; 116 117 DBG("wf_lm75: creating %s device at address 0x%02x\n", 118 ds1775 ? "ds1775" : "lm75", addr); 119 120 lm = kzalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL); 121 if (lm == NULL) 122 return NULL; 123 124 /* Usual rant about sensor names not beeing very consistent in 125 * the device-tree, oh well ... 126 * Add more entries below as you deal with more setups 127 */ 128 if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY")) 129 lm->sens.name = "hd-temp"; 130 else if (!strcmp(loc, "Incoming Air Temp")) 131 lm->sens.name = "incoming-air-temp"; 132 else if (!strcmp(loc, "ODD Temp")) 133 lm->sens.name = "optical-drive-temp"; 134 else if (!strcmp(loc, "HD Temp")) 135 lm->sens.name = "hard-drive-temp"; 136 else 137 goto fail; 138 139 lm->inited = 0; 140 lm->sens.ops = &wf_lm75_ops; 141 lm->ds1775 = ds1775; 142 lm->i2c.addr = (addr >> 1) & 0x7f; 143 lm->i2c.adapter = adapter; 144 lm->i2c.driver = &wf_lm75_driver; 145 strncpy(lm->i2c.name, lm->sens.name, I2C_NAME_SIZE-1); 146 147 rc = i2c_attach_client(&lm->i2c); 148 if (rc) { 149 printk(KERN_ERR "windfarm: failed to attach %s %s to i2c," 150 " err %d\n", ds1775 ? "ds1775" : "lm75", 151 lm->i2c.name, rc); 152 goto fail; 153 } 154 155 if (wf_register_sensor(&lm->sens)) { 156 i2c_detach_client(&lm->i2c); 157 goto fail; 158 } 159 160 return lm; 161 fail: 162 kfree(lm); 163 return NULL; 164 } 165 166 static int wf_lm75_attach(struct i2c_adapter *adapter) 167 { 168 struct device_node *busnode, *dev; 169 struct pmac_i2c_bus *bus; 170 171 DBG("wf_lm75: adapter %s detected\n", adapter->name); 172 173 bus = pmac_i2c_adapter_to_bus(adapter); 174 if (bus == NULL) 175 return -ENODEV; 176 busnode = pmac_i2c_get_bus_node(bus); 177 178 DBG("wf_lm75: bus found, looking for device...\n"); 179 180 /* Now look for lm75(s) in there */ 181 for (dev = NULL; 182 (dev = of_get_next_child(busnode, dev)) != NULL;) { 183 const char *loc = 184 of_get_property(dev, "hwsensor-location", NULL); 185 u8 addr; 186 187 /* We must re-match the adapter in order to properly check 188 * the channel on multibus setups 189 */ 190 if (!pmac_i2c_match_adapter(dev, adapter)) 191 continue; 192 addr = pmac_i2c_get_dev_addr(dev); 193 if (loc == NULL || addr == 0) 194 continue; 195 /* real lm75 */ 196 if (of_device_is_compatible(dev, "lm75")) 197 wf_lm75_create(adapter, addr, 0, loc); 198 /* ds1775 (compatible, better resolution */ 199 else if (of_device_is_compatible(dev, "ds1775")) 200 wf_lm75_create(adapter, addr, 1, loc); 201 } 202 return 0; 203 } 204 205 static int wf_lm75_detach(struct i2c_client *client) 206 { 207 struct wf_lm75_sensor *lm = i2c_to_lm75(client); 208 209 DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name); 210 211 /* Mark client detached */ 212 lm->i2c.adapter = NULL; 213 214 /* release sensor */ 215 wf_unregister_sensor(&lm->sens); 216 217 return 0; 218 } 219 220 static int __init wf_lm75_sensor_init(void) 221 { 222 /* Don't register on old machines that use therm_pm72 for now */ 223 if (machine_is_compatible("PowerMac7,2") || 224 machine_is_compatible("PowerMac7,3") || 225 machine_is_compatible("RackMac3,1")) 226 return -ENODEV; 227 return i2c_add_driver(&wf_lm75_driver); 228 } 229 230 static void __exit wf_lm75_sensor_exit(void) 231 { 232 i2c_del_driver(&wf_lm75_driver); 233 } 234 235 236 module_init(wf_lm75_sensor_init); 237 module_exit(wf_lm75_sensor_exit); 238 239 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); 240 MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control"); 241 MODULE_LICENSE("GPL"); 242 243