drivers/macintosh/windfarm_lm75_sensor.c

   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