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/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
  45 static 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
  79 static 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
  86 static struct wf_sensor_ops wf_lm75_ops = {
  87         .get_value      = wf_lm75_get,
  88         .release        = wf_lm75_release,
  89         .owner          = THIS_MODULE,
  90 };
  91
  92 static 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                 i2c_set_clientdata(client, NULL);
 112                 kfree(lm);
 113         }
 114
 115         return rc;
 116 }
 117
 118 static struct i2c_driver wf_lm75_driver;
 119
 120 static struct i2c_client *wf_lm75_create(struct i2c_adapter *adapter,
 121                                              u8 addr, int ds1775,
 122                                              const char *loc)
 123 {
 124         struct i2c_board_info info;
 125         struct i2c_client *client;
 126         char *name;
 127
 128         DBG("wf_lm75: creating  %s device at address 0x%02x\n",
 129             ds1775 ? "ds1775" : "lm75", addr);
 130
 131         /* Usual rant about sensor names not beeing very consistent in
 132          * the device-tree, oh well ...
 133          * Add more entries below as you deal with more setups
 134          */
 135         if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY"))
 136                 name = "hd-temp";
 137         else if (!strcmp(loc, "Incoming Air Temp"))
 138                 name = "incoming-air-temp";
 139         else if (!strcmp(loc, "ODD Temp"))
 140                 name = "optical-drive-temp";
 141         else if (!strcmp(loc, "HD Temp"))
 142                 name = "hard-drive-temp";
 143         else
 144                 goto fail;
 145
 146         memset(&info, 0, sizeof(struct i2c_board_info));
 147         info.addr = (addr >> 1) & 0x7f;
 148         info.platform_data = name;
 149         strlcpy(info.type, ds1775 ? "wf_ds1775" : "wf_lm75", I2C_NAME_SIZE);
 150
 151         client = i2c_new_device(adapter, &info);
 152         if (client == NULL) {
 153                 printk(KERN_ERR "windfarm: failed to attach %s %s to i2c\n",
 154                        ds1775 ? "ds1775" : "lm75", name);
 155                 goto fail;
 156         }
 157
 158         /*
 159          * Let i2c-core delete that device on driver removal.
 160          * This is safe because i2c-core holds the core_lock mutex for us.
 161          */
 162         list_add_tail(&client->detected, &wf_lm75_driver.clients);
 163         return client;
 164  fail:
 165         return NULL;
 166 }
 167
 168 static int wf_lm75_attach(struct i2c_adapter *adapter)
 169 {
 170         struct device_node *busnode, *dev;
 171         struct pmac_i2c_bus *bus;
 172
 173         DBG("wf_lm75: adapter %s detected\n", adapter->name);
 174
 175         bus = pmac_i2c_adapter_to_bus(adapter);
 176         if (bus == NULL)
 177                 return -ENODEV;
 178         busnode = pmac_i2c_get_bus_node(bus);
 179
 180         DBG("wf_lm75: bus found, looking for device...\n");
 181
 182         /* Now look for lm75(s) in there */
 183         for (dev = NULL;
 184              (dev = of_get_next_child(busnode, dev)) != NULL;) {
 185                 const char *loc =
 186                         of_get_property(dev, "hwsensor-location", NULL);
 187                 u8 addr;
 188
 189                 /* We must re-match the adapter in order to properly check
 190                  * the channel on multibus setups
 191                  */
 192                 if (!pmac_i2c_match_adapter(dev, adapter))
 193                         continue;
 194                 addr = pmac_i2c_get_dev_addr(dev);
 195                 if (loc == NULL || addr == 0)
 196                         continue;
 197                 /* real lm75 */
 198                 if (of_device_is_compatible(dev, "lm75"))
 199                         wf_lm75_create(adapter, addr, 0, loc);
 200                 /* ds1775 (compatible, better resolution */
 201                 else if (of_device_is_compatible(dev, "ds1775"))
 202                         wf_lm75_create(adapter, addr, 1, loc);
 203         }
 204         return 0;
 205 }
 206
 207 static int wf_lm75_remove(struct i2c_client *client)
 208 {
 209         struct wf_lm75_sensor *lm = i2c_get_clientdata(client);
 210
 211         DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name);
 212
 213         /* Mark client detached */
 214         lm->i2c = NULL;
 215
 216         /* release sensor */
 217         wf_unregister_sensor(&lm->sens);
 218
 219         i2c_set_clientdata(client, NULL);
 220         return 0;
 221 }
 222
 223 static const struct i2c_device_id wf_lm75_id[] = {
 224         { "wf_lm75", 0 },
 225         { "wf_ds1775", 1 },
 226         { }
 227 };
 228
 229 static struct i2c_driver wf_lm75_driver = {
 230         .driver = {
 231                 .name   = "wf_lm75",
 232         },
 233         .attach_adapter = wf_lm75_attach,
 234         .probe          = wf_lm75_probe,
 235         .remove         = wf_lm75_remove,
 236         .id_table       = wf_lm75_id,
 237 };
 238
 239 static int __init wf_lm75_sensor_init(void)
 240 {
 241         /* Don't register on old machines that use therm_pm72 for now */
 242         if (of_machine_is_compatible("PowerMac7,2") ||
 243             of_machine_is_compatible("PowerMac7,3") ||
 244             of_machine_is_compatible("RackMac3,1"))
 245                 return -ENODEV;
 246         return i2c_add_driver(&wf_lm75_driver);
 247 }
 248
 249 static void __exit wf_lm75_sensor_exit(void)
 250 {
 251         i2c_del_driver(&wf_lm75_driver);
 252 }
 253
 254
 255 module_init(wf_lm75_sensor_init);
 256 module_exit(wf_lm75_sensor_exit);
 257
 258 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
 259 MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
 260 MODULE_LICENSE("GPL");
 261