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 = kmalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL); 121 if (lm == NULL) 122 return NULL; 123 memset(lm, 0, sizeof(struct wf_lm75_sensor)); 124 125 /* 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 128 */ 129 if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY")) 130 lm->sens.name = "hd-temp"; 131 else 132 goto fail; 133 134 lm->inited = 0; 135 lm->sens.ops = &wf_lm75_ops; 136 lm->ds1775 = ds1775; 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); 141 142 rc = i2c_attach_client(&lm->i2c); 143 if (rc) { 144 printk(KERN_ERR "windfarm: failed to attach %s %s to i2c," 145 " err %d\n", ds1775 ? "ds1775" : "lm75", 146 lm->i2c.name, rc); 147 goto fail; 148 } 149 150 if (wf_register_sensor(&lm->sens)) { 151 i2c_detach_client(&lm->i2c); 152 goto fail; 153 } 154 155 return lm; 156 fail: 157 kfree(lm); 158 return NULL; 159 } 160 161 static int wf_lm75_attach(struct i2c_adapter *adapter) 162 { 163 struct device_node *busnode, *dev; 164 struct pmac_i2c_bus *bus; 165 166 DBG("wf_lm75: adapter %s detected\n", adapter->name); 167 168 bus = pmac_i2c_adapter_to_bus(adapter); 169 if (bus == NULL) 170 return -ENODEV; 171 busnode = pmac_i2c_get_bus_node(bus); 172 173 DBG("wf_lm75: bus found, looking for device...\n"); 174 175 /* Now look for lm75(s) in there */ 176 for (dev = NULL; 177 (dev = of_get_next_child(busnode, dev)) != NULL;) { 178 const char *loc = 179 get_property(dev, "hwsensor-location", NULL); 180 u8 addr; 181 182 /* We must re-match the adapter in order to properly check 183 * the channel on multibus setups 184 */ 185 if (!pmac_i2c_match_adapter(dev, adapter)) 186 continue; 187 addr = pmac_i2c_get_dev_addr(dev); 188 if (loc == NULL || addr == 0) 189 continue; 190 /* real lm75 */ 191 if (device_is_compatible(dev, "lm75")) 192 wf_lm75_create(adapter, addr, 0, loc); 193 /* ds1775 (compatible, better resolution */ 194 else if (device_is_compatible(dev, "ds1775")) 195 wf_lm75_create(adapter, addr, 1, loc); 196 } 197 return 0; 198 } 199 200 static int wf_lm75_detach(struct i2c_client *client) 201 { 202 struct wf_lm75_sensor *lm = i2c_to_lm75(client); 203 204 DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name); 205 206 /* Mark client detached */ 207 lm->i2c.adapter = NULL; 208 209 /* release sensor */ 210 wf_unregister_sensor(&lm->sens); 211 212 return 0; 213 } 214 215 static int __init wf_lm75_sensor_init(void) 216 { 217 /* Don't register on old machines that use therm_pm72 for now */ 218 if (machine_is_compatible("PowerMac7,2") || 219 machine_is_compatible("PowerMac7,3") || 220 machine_is_compatible("RackMac3,1")) 221 return -ENODEV; 222 return i2c_add_driver(&wf_lm75_driver); 223 } 224 225 static void __exit wf_lm75_sensor_exit(void) 226 { 227 i2c_del_driver(&wf_lm75_driver); 228 } 229 230 231 module_init(wf_lm75_sensor_init); 232 module_exit(wf_lm75_sensor_exit); 233 234 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); 235 MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control"); 236 MODULE_LICENSE("GPL"); 237 238