1/* 2 * Windfarm PowerMac thermal control. MAX6690 sensor. 3 * 4 * Copyright (C) 2005 Paul Mackerras, IBM Corp. <paulus@samba.org> 5 * 6 * Use and redistribute under the terms of the GNU GPL v2. 7 */ 8#include <linux/types.h> 9#include <linux/errno.h> 10#include <linux/kernel.h> 11#include <linux/init.h> 12#include <linux/slab.h> 13#include <linux/i2c.h> 14#include <asm/prom.h> 15#include <asm/pmac_low_i2c.h> 16 17#include "windfarm.h" 18 19#define VERSION "0.2" 20 21/* This currently only exports the external temperature sensor, 22 since that's all the control loops need. */ 23 24/* Some MAX6690 register numbers */ 25#define MAX6690_INTERNAL_TEMP 0 26#define MAX6690_EXTERNAL_TEMP 1 27 28struct wf_6690_sensor { 29 struct i2c_client *i2c; 30 struct wf_sensor sens; 31}; 32 33#define wf_to_6690(x) container_of((x), struct wf_6690_sensor, sens) 34 35static int wf_max6690_get(struct wf_sensor *sr, s32 *value) 36{ 37 struct wf_6690_sensor *max = wf_to_6690(sr); 38 s32 data; 39 40 if (max->i2c == NULL) 41 return -ENODEV; 42 43 /* chip gets initialized by firmware */ 44 data = i2c_smbus_read_byte_data(max->i2c, MAX6690_EXTERNAL_TEMP); 45 if (data < 0) 46 return data; 47 *value = data << 16; 48 return 0; 49} 50 51static void wf_max6690_release(struct wf_sensor *sr) 52{ 53 struct wf_6690_sensor *max = wf_to_6690(sr); 54 55 kfree(max); 56} 57 58static struct wf_sensor_ops wf_max6690_ops = { 59 .get_value = wf_max6690_get, 60 .release = wf_max6690_release, 61 .owner = THIS_MODULE, 62}; 63 64static int wf_max6690_probe(struct i2c_client *client, 65 const struct i2c_device_id *id) 66{ 67 struct wf_6690_sensor *max; 68 int rc; 69 70 max = kzalloc(sizeof(struct wf_6690_sensor), GFP_KERNEL); 71 if (max == NULL) { 72 printk(KERN_ERR "windfarm: Couldn't create MAX6690 sensor: " 73 "no memory\n"); 74 return -ENOMEM; 75 } 76 77 max->i2c = client; 78 max->sens.name = client->dev.platform_data; 79 max->sens.ops = &wf_max6690_ops; 80 i2c_set_clientdata(client, max); 81 82 rc = wf_register_sensor(&max->sens); 83 if (rc) { 84 kfree(max); 85 } 86 87 return rc; 88} 89 90static struct i2c_driver wf_max6690_driver; 91 92static struct i2c_client *wf_max6690_create(struct i2c_adapter *adapter, 93 u8 addr, const char *loc) 94{ 95 struct i2c_board_info info; 96 struct i2c_client *client; 97 char *name; 98 99 if (!strcmp(loc, "BACKSIDE")) 100 name = "backside-temp"; 101 else if (!strcmp(loc, "NB Ambient")) 102 name = "north-bridge-temp"; 103 else if (!strcmp(loc, "GPU Ambient")) 104 name = "gpu-temp"; 105 else 106 goto fail; 107 108 memset(&info, 0, sizeof(struct i2c_board_info)); 109 info.addr = addr >> 1; 110 info.platform_data = name; 111 strlcpy(info.type, "wf_max6690", I2C_NAME_SIZE); 112 113 client = i2c_new_device(adapter, &info); 114 if (client == NULL) { 115 printk(KERN_ERR "windfarm: failed to attach MAX6690 sensor\n"); 116 goto fail; 117 } 118 119 /* 120 * Let i2c-core delete that device on driver removal. 121 * This is safe because i2c-core holds the core_lock mutex for us. 122 */ 123 list_add_tail(&client->detected, &wf_max6690_driver.clients); 124 return client; 125 126 fail: 127 return NULL; 128} 129 130static int wf_max6690_attach(struct i2c_adapter *adapter) 131{ 132 struct device_node *busnode, *dev = NULL; 133 struct pmac_i2c_bus *bus; 134 const char *loc; 135 136 bus = pmac_i2c_adapter_to_bus(adapter); 137 if (bus == NULL) 138 return -ENODEV; 139 busnode = pmac_i2c_get_bus_node(bus); 140 141 while ((dev = of_get_next_child(busnode, dev)) != NULL) { 142 u8 addr; 143 144 /* We must re-match the adapter in order to properly check 145 * the channel on multibus setups 146 */ 147 if (!pmac_i2c_match_adapter(dev, adapter)) 148 continue; 149 if (!of_device_is_compatible(dev, "max6690")) 150 continue; 151 addr = pmac_i2c_get_dev_addr(dev); 152 loc = of_get_property(dev, "hwsensor-location", NULL); 153 if (loc == NULL || addr == 0) 154 continue; 155 printk("found max6690, loc=%s addr=0x%02x\n", loc, addr); 156 wf_max6690_create(adapter, addr, loc); 157 } 158 159 return 0; 160} 161 162static int wf_max6690_remove(struct i2c_client *client) 163{ 164 struct wf_6690_sensor *max = i2c_get_clientdata(client); 165 166 max->i2c = NULL; 167 wf_unregister_sensor(&max->sens); 168 169 return 0; 170} 171 172static const struct i2c_device_id wf_max6690_id[] = { 173 { "wf_max6690", 0 }, 174 { } 175}; 176 177static struct i2c_driver wf_max6690_driver = { 178 .driver = { 179 .name = "wf_max6690", 180 }, 181 .attach_adapter = wf_max6690_attach, 182 .probe = wf_max6690_probe, 183 .remove = wf_max6690_remove, 184 .id_table = wf_max6690_id, 185}; 186 187static int __init wf_max6690_sensor_init(void) 188{ 189 /* Don't register on old machines that use therm_pm72 for now */ 190 if (of_machine_is_compatible("PowerMac7,2") || 191 of_machine_is_compatible("PowerMac7,3") || 192 of_machine_is_compatible("RackMac3,1")) 193 return -ENODEV; 194 return i2c_add_driver(&wf_max6690_driver); 195} 196 197static void __exit wf_max6690_sensor_exit(void) 198{ 199 i2c_del_driver(&wf_max6690_driver); 200} 201 202module_init(wf_max6690_sensor_init); 203module_exit(wf_max6690_sensor_exit); 204 205MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>"); 206MODULE_DESCRIPTION("MAX6690 sensor objects for PowerMac thermal control"); 207MODULE_LICENSE("GPL"); 208