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 "1.0"
  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 const 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, ds1775 = id->driver_data;
  96         const char *name, *loc;
  97
  98         DBG("wf_lm75: creating  %s device at address 0x%02x\n",
  99             ds1775 ? "ds1775" : "lm75", client->addr);
 100
 101         loc = of_get_property(client->dev.of_node, "hwsensor-location", NULL);
 102         if (!loc) {
 103                 dev_warn(&client->dev, "Missing hwsensor-location property!\n");
 104                 return -ENXIO;
 105         }
 106
 107         /* Usual rant about sensor names not beeing very consistent in
 108          * the device-tree, oh well ...
 109          * Add more entries below as you deal with more setups
 110          */
 111         if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY"))
 112                 name = "hd-temp";
 113         else if (!strcmp(loc, "Incoming Air Temp"))
 114                 name = "incoming-air-temp";
 115         else if (!strcmp(loc, "ODD Temp"))
 116                 name = "optical-drive-temp";
 117         else if (!strcmp(loc, "HD Temp"))
 118                 name = "hard-drive-temp";
 119         else if (!strcmp(loc, "PCI SLOTS"))
 120                 name = "slots-temp";
 121         else if (!strcmp(loc, "CPU A INLET"))
 122                 name = "cpu-inlet-temp-0";
 123         else if (!strcmp(loc, "CPU B INLET"))
 124                 name = "cpu-inlet-temp-1";
 125         else
 126                 return -ENXIO;
 127
 128
 129         lm = kzalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL);
 130         if (lm == NULL)
 131                 return -ENODEV;
 132
 133         lm->inited = 0;
 134         lm->ds1775 = ds1775;
 135         lm->i2c = client;
 136         lm->sens.name = name;
 137         lm->sens.ops = &wf_lm75_ops;
 138         i2c_set_clientdata(client, lm);
 139
 140         rc = wf_register_sensor(&lm->sens);
 141         if (rc)
 142                 kfree(lm);
 143         return rc;
 144 }
 145
 146 static int wf_lm75_remove(struct i2c_client *client)
 147 {
 148         struct wf_lm75_sensor *lm = i2c_get_clientdata(client);
 149
 150         DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name);
 151
 152         /* Mark client detached */
 153         lm->i2c = NULL;
 154
 155         /* release sensor */
 156         wf_unregister_sensor(&lm->sens);
 157
 158         return 0;
 159 }
 160
 161 static const struct i2c_device_id wf_lm75_id[] = {
 162         { "MAC,lm75", 0 },
 163         { "MAC,ds1775", 1 },
 164         { }
 165 };
 166 MODULE_DEVICE_TABLE(i2c, wf_lm75_id);
 167
 168 static struct i2c_driver wf_lm75_driver = {
 169         .driver = {
 170                 .name   = "wf_lm75",
 171         },
 172         .probe          = wf_lm75_probe,
 173         .remove         = wf_lm75_remove,
 174         .id_table       = wf_lm75_id,
 175 };
 176
 177 module_i2c_driver(wf_lm75_driver);
 178
 179 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
 180 MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
 181 MODULE_LICENSE("GPL");
 182