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 37struct 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 45static 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 79static 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 86static struct wf_sensor_ops wf_lm75_ops = { 87 .get_value = wf_lm75_get, 88 .release = wf_lm75_release, 89 .owner = THIS_MODULE, 90}; 91 92static 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 kfree(lm); 112 113 return rc; 114} 115 116static struct i2c_driver wf_lm75_driver; 117 118static struct i2c_client *wf_lm75_create(struct i2c_adapter *adapter, 119 u8 addr, int ds1775, 120 const char *loc) 121{ 122 struct i2c_board_info info; 123 struct i2c_client *client; 124 char *name; 125 126 DBG("wf_lm75: creating %s device at address 0x%02x\n", 127 ds1775 ? "ds1775" : "lm75", addr); 128 129 /* Usual rant about sensor names not beeing very consistent in 130 * the device-tree, oh well ... 131 * Add more entries below as you deal with more setups 132 */ 133 if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY")) 134 name = "hd-temp"; 135 else if (!strcmp(loc, "Incoming Air Temp")) 136 name = "incoming-air-temp"; 137 else if (!strcmp(loc, "ODD Temp")) 138 name = "optical-drive-temp"; 139 else if (!strcmp(loc, "HD Temp")) 140 name = "hard-drive-temp"; 141 else 142 goto fail; 143 144 memset(&info, 0, sizeof(struct i2c_board_info)); 145 info.addr = (addr >> 1) & 0x7f; 146 info.platform_data = name; 147 strlcpy(info.type, ds1775 ? "wf_ds1775" : "wf_lm75", I2C_NAME_SIZE); 148 149 client = i2c_new_device(adapter, &info); 150 if (client == NULL) { 151 printk(KERN_ERR "windfarm: failed to attach %s %s to i2c\n", 152 ds1775 ? "ds1775" : "lm75", name); 153 goto fail; 154 } 155 156 /* 157 * Let i2c-core delete that device on driver removal. 158 * This is safe because i2c-core holds the core_lock mutex for us. 159 */ 160 list_add_tail(&client->detected, &wf_lm75_driver.clients); 161 return client; 162 fail: 163 return NULL; 164} 165 166static 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 205static int wf_lm75_remove(struct i2c_client *client) 206{ 207 struct wf_lm75_sensor *lm = i2c_get_clientdata(client); 208 209 DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name); 210 211 /* Mark client detached */ 212 lm->i2c = NULL; 213 214 /* release sensor */ 215 wf_unregister_sensor(&lm->sens); 216 217 return 0; 218} 219 220static const struct i2c_device_id wf_lm75_id[] = { 221 { "wf_lm75", 0 }, 222 { "wf_ds1775", 1 }, 223 { } 224}; 225 226static struct i2c_driver wf_lm75_driver = { 227 .driver = { 228 .name = "wf_lm75", 229 }, 230 .attach_adapter = wf_lm75_attach, 231 .probe = wf_lm75_probe, 232 .remove = wf_lm75_remove, 233 .id_table = wf_lm75_id, 234}; 235 236static int __init wf_lm75_sensor_init(void) 237{ 238 /* Don't register on old machines that use therm_pm72 for now */ 239 if (of_machine_is_compatible("PowerMac7,2") || 240 of_machine_is_compatible("PowerMac7,3") || 241 of_machine_is_compatible("RackMac3,1")) 242 return -ENODEV; 243 return i2c_add_driver(&wf_lm75_driver); 244} 245 246static void __exit wf_lm75_sensor_exit(void) 247{ 248 i2c_del_driver(&wf_lm75_driver); 249} 250 251 252module_init(wf_lm75_sensor_init); 253module_exit(wf_lm75_sensor_exit); 254 255MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); 256MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control"); 257MODULE_LICENSE("GPL"); 258