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 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"); 182 183