err.no Git - linux-2.6/blob - 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 <linux/i2c-dev.h>
  19 #include <asm/prom.h>
  20 #include <asm/machdep.h>
  21 #include <asm/io.h>
  22 #include <asm/system.h>
  23 #include <asm/sections.h>
  24
  25 #include "windfarm.h"
  26
  27 #define VERSION "0.1"
  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 #define i2c_to_lm75(c) container_of(c, struct wf_lm75_sensor, i2c)
  45
  46 static int wf_lm75_attach(struct i2c_adapter *adapter);
  47 static int wf_lm75_detach(struct i2c_client *client);
  48
  49 static struct i2c_driver wf_lm75_driver = {
  50         .owner          = THIS_MODULE,
  51         .name           = "wf_lm75",
  52         .attach_adapter = wf_lm75_attach,
  53         .detach_client  = wf_lm75_detach,
  54 };
  55
  56 static int wf_lm75_get(struct wf_sensor *sr, s32 *value)
  57 {
  58         struct wf_lm75_sensor *lm = wf_to_lm75(sr);
  59         s32 data;
  60
  61         if (lm->i2c.adapter == NULL)
  62                 return -ENODEV;
  63
  64         /* Init chip if necessary */
  65         if (!lm->inited) {
  66                 u8 cfg_new, cfg = (u8)i2c_smbus_read_byte_data(&lm->i2c, 1);
  67
  68                 DBG("wf_lm75: Initializing %s, cfg was: %02x\n",
  69                     sr->name, cfg);
  70
  71                 /* clear shutdown bit, keep other settings as left by
  72                  * the firmware for now
  73                  */
  74                 cfg_new = cfg & ~0x01;
  75                 i2c_smbus_write_byte_data(&lm->i2c, 1, cfg_new);
  76                 lm->inited = 1;
  77
  78                 /* If we just powered it up, let's wait 200 ms */
  79                 msleep(200);
  80         }
  81
  82         /* Read temperature register */
  83         data = (s32)le16_to_cpu(i2c_smbus_read_word_data(&lm->i2c, 0));
  84         data <<= 8;
  85         *value = data;
  86
  87         return 0;
  88 }
  89
  90 static void wf_lm75_release(struct wf_sensor *sr)
  91 {
  92         struct wf_lm75_sensor *lm = wf_to_lm75(sr);
  93
  94         /* check if client is registered and detach from i2c */
  95         if (lm->i2c.adapter) {
  96                 i2c_detach_client(&lm->i2c);
  97                 lm->i2c.adapter = NULL;
  98         }
  99
 100         kfree(lm);
 101 }
 102
 103 static struct wf_sensor_ops wf_lm75_ops = {
 104         .get_value      = wf_lm75_get,
 105         .release        = wf_lm75_release,
 106         .owner          = THIS_MODULE,
 107 };
 108
 109 static struct wf_lm75_sensor *wf_lm75_create(struct i2c_adapter *adapter,
 110                                              u8 addr, int ds1775,
 111                                              const char *loc)
 112 {
 113         struct wf_lm75_sensor *lm;
 114
 115         DBG("wf_lm75: creating  %s device at address 0x%02x\n",
 116             ds1775 ? "ds1775" : "lm75", addr);
 117
 118         lm = kmalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL);
 119         if (lm == NULL)
 120                 return NULL;
 121         memset(lm, 0, sizeof(struct wf_lm75_sensor));
 122
 123         /* Usual rant about sensor names not beeing very consistent in
 124          * the device-tree, oh well ...
 125          * Add more entries below as you deal with more setups
 126          */
 127         if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY"))
 128                 lm->sens.name = "hd-temp";
 129         else
 130                 goto fail;
 131
 132         lm->inited = 0;
 133         lm->sens.ops = &wf_lm75_ops;
 134         lm->ds1775 = ds1775;
 135         lm->i2c.addr = (addr >> 1) & 0x7f;
 136         lm->i2c.adapter = adapter;
 137         lm->i2c.driver = &wf_lm75_driver;
 138         strncpy(lm->i2c.name, lm->sens.name, I2C_NAME_SIZE-1);
 139
 140         if (i2c_attach_client(&lm->i2c)) {
 141                 printk(KERN_ERR "windfarm: failed to attach %s %s to i2c\n",
 142                        ds1775 ? "ds1775" : "lm75", lm->i2c.name);
 143                 goto fail;
 144         }
 145
 146         if (wf_register_sensor(&lm->sens)) {
 147                 i2c_detach_client(&lm->i2c);
 148                 goto fail;
 149         }
 150
 151         return lm;
 152  fail:
 153         kfree(lm);
 154         return NULL;
 155 }
 156
 157 static int wf_lm75_attach(struct i2c_adapter *adapter)
 158 {
 159         u8 bus_id;
 160         struct device_node *smu, *bus, *dev;
 161
 162         /* We currently only deal with LM75's hanging off the SMU
 163          * i2c busses. If we extend that driver to other/older
 164          * machines, we should split this function into SMU-i2c,
 165          * keywest-i2c, PMU-i2c, ...
 166          */
 167
 168         DBG("wf_lm75: adapter %s detected\n", adapter->name);
 169
 170         if (strncmp(adapter->name, "smu-i2c-", 8) != 0)
 171                 return 0;
 172         smu = of_find_node_by_type(NULL, "smu");
 173         if (smu == NULL)
 174                 return 0;
 175
 176         /* Look for the bus in the device-tree */
 177         bus_id = (u8)simple_strtoul(adapter->name + 8, NULL, 16);
 178
 179         DBG("wf_lm75: bus ID is %x\n", bus_id);
 180
 181         /* Look for sensors subdir */
 182         for (bus = NULL;
 183              (bus = of_get_next_child(smu, bus)) != NULL;) {
 184                 u32 *reg;
 185
 186                 if (strcmp(bus->name, "i2c"))
 187                         continue;
 188                 reg = (u32 *)get_property(bus, "reg", NULL);
 189                 if (reg == NULL)
 190                         continue;
 191                 if (bus_id == *reg)
 192                         break;
 193         }
 194         of_node_put(smu);
 195         if (bus == NULL) {
 196                 printk(KERN_WARNING "windfarm: SMU i2c bus 0x%x not found"
 197                        " in device-tree !\n", bus_id);
 198                 return 0;
 199         }
 200
 201         DBG("wf_lm75: bus found, looking for device...\n");
 202
 203         /* Now look for lm75(s) in there */
 204         for (dev = NULL;
 205              (dev = of_get_next_child(bus, dev)) != NULL;) {
 206                 const char *loc =
 207                         get_property(dev, "hwsensor-location", NULL);
 208                 u32 *reg = (u32 *)get_property(dev, "reg", NULL);
 209                 DBG(" dev: %s... (loc: %p, reg: %p)\n", dev->name, loc, reg);
 210                 if (loc == NULL || reg == NULL)
 211                         continue;
 212                 /* real lm75 */
 213                 if (device_is_compatible(dev, "lm75"))
 214                         wf_lm75_create(adapter, *reg, 0, loc);
 215                 /* ds1775 (compatible, better resolution */
 216                 else if (device_is_compatible(dev, "ds1775"))
 217                         wf_lm75_create(adapter, *reg, 1, loc);
 218         }
 219
 220         of_node_put(bus);
 221
 222         return 0;
 223 }
 224
 225 static int wf_lm75_detach(struct i2c_client *client)
 226 {
 227         struct wf_lm75_sensor *lm = i2c_to_lm75(client);
 228
 229         DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name);
 230
 231         /* Mark client detached */
 232         lm->i2c.adapter = NULL;
 233
 234         /* release sensor */
 235         wf_unregister_sensor(&lm->sens);
 236
 237         return 0;
 238 }
 239
 240 static int __init wf_lm75_sensor_init(void)
 241 {
 242         int rc;
 243
 244         rc = i2c_add_driver(&wf_lm75_driver);
 245         if (rc < 0)
 246                 return rc;
 247         return 0;
 248 }
 249
 250 static void __exit wf_lm75_sensor_exit(void)
 251 {
 252         i2c_del_driver(&wf_lm75_driver);
 253 }
 254
 255
 256 module_init(wf_lm75_sensor_init);
 257 module_exit(wf_lm75_sensor_exit);
 258
 259 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
 260 MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
 261 MODULE_LICENSE("GPL");
 262