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                 kfree(lm);
 112
 113         return rc;
 114 }
 115
 116 static struct i2c_driver wf_lm75_driver;
 117
 118 static 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
 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_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
 220 static const struct i2c_device_id wf_lm75_id[] = {
 221         { "wf_lm75", 0 },
 222         { "wf_ds1775", 1 },
 223         { }
 224 };
 225
 226 static 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
 236 static 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
 246 static void __exit wf_lm75_sensor_exit(void)
 247 {
 248         i2c_del_driver(&wf_lm75_driver);
 249 }
 250
 251
 252 module_init(wf_lm75_sensor_init);
 253 module_exit(wf_lm75_sensor_exit);
 254
 255 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
 256 MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
 257 MODULE_LICENSE("GPL");
 258