/* * Windfarm PowerMac thermal control. MAX6690 sensor. * * Copyright (C) 2005 Paul Mackerras, IBM Corp. <paulus@samba.org> * * Use and redistribute under the terms of the GNU GPL v2. */ #include <linux/types.h> #include <linux/errno.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/i2c.h> #include <asm/prom.h> #include <asm/pmac_low_i2c.h> #include "windfarm.h" #define VERSION "0.2" /* This currently only exports the external temperature sensor, since that's all the control loops need. */ /* Some MAX6690 register numbers */ #define MAX6690_INTERNAL_TEMP 0 #define MAX6690_EXTERNAL_TEMP 1 struct wf_6690_sensor { struct i2c_client i2c; struct wf_sensor sens; }; #define wf_to_6690(x) container_of((x), struct wf_6690_sensor, sens) #define i2c_to_6690(x) container_of((x), struct wf_6690_sensor, i2c) static int wf_max6690_attach(struct i2c_adapter *adapter); static int wf_max6690_detach(struct i2c_client *client); static struct i2c_driver wf_max6690_driver = { .driver = { .name = "wf_max6690", }, .attach_adapter = wf_max6690_attach, .detach_client = wf_max6690_detach, }; static int wf_max6690_get(struct wf_sensor *sr, s32 *value) { struct wf_6690_sensor *max = wf_to_6690(sr); s32 data; if (max->i2c.adapter == NULL) return -ENODEV; /* chip gets initialized by firmware */ data = i2c_smbus_read_byte_data(&max->i2c, MAX6690_EXTERNAL_TEMP); if (data < 0) return data; *value = data << 16; return 0; } static void wf_max6690_release(struct wf_sensor *sr) { struct wf_6690_sensor *max = wf_to_6690(sr); if (max->i2c.adapter) { i2c_detach_client(&max->i2c); max->i2c.adapter = NULL; } kfree(max); } static struct wf_sensor_ops wf_max6690_ops = { .get_value = wf_max6690_get, .release = wf_max6690_release, .owner = THIS_MODULE, }; static void wf_max6690_create(struct i2c_adapter *adapter, u8 addr) { struct wf_6690_sensor *max; char *name = "backside-temp"; max = kzalloc(sizeof(struct wf_6690_sensor), GFP_KERNEL); if (max == NULL) { printk(KERN_ERR "windfarm: Couldn't create MAX6690 sensor %s: " "no memory\n", name); return; } max->sens.ops = &wf_max6690_ops; max->sens.name = name; max->i2c.addr = addr >> 1; max->i2c.adapter = adapter; max->i2c.driver = &wf_max6690_driver; strncpy(max->i2c.name, name, I2C_NAME_SIZE-1); if (i2c_attach_client(&max->i2c)) { printk(KERN_ERR "windfarm: failed to attach MAX6690 sensor\n"); goto fail; } if (wf_register_sensor(&max->sens)) { i2c_detach_client(&max->i2c); goto fail; } return; fail: kfree(max); } static int wf_max6690_attach(struct i2c_adapter *adapter) { struct device_node *busnode, *dev = NULL; struct pmac_i2c_bus *bus; const char *loc; bus = pmac_i2c_adapter_to_bus(adapter); if (bus == NULL) return -ENODEV; busnode = pmac_i2c_get_bus_node(bus); while ((dev = of_get_next_child(busnode, dev)) != NULL) { u8 addr; /* We must re-match the adapter in order to properly check * the channel on multibus setups */ if (!pmac_i2c_match_adapter(dev, adapter)) continue; if (!device_is_compatible(dev, "max6690")) continue; addr = pmac_i2c_get_dev_addr(dev); loc = get_property(dev, "hwsensor-location", NULL); if (loc == NULL || addr == 0) continue; printk("found max6690, loc=%s addr=0x%02x\n", loc, addr); if (strcmp(loc, "BACKSIDE")) continue; wf_max6690_create(adapter, addr); } return 0; } static int wf_max6690_detach(struct i2c_client *client) { struct wf_6690_sensor *max = i2c_to_6690(client); max->i2c.adapter = NULL; wf_unregister_sensor(&max->sens); return 0; } static int __init wf_max6690_sensor_init(void) { /* Don't register on old machines that use therm_pm72 for now */ if (machine_is_compatible("PowerMac7,2") || machine_is_compatible("PowerMac7,3") || machine_is_compatible("RackMac3,1")) return -ENODEV; return i2c_add_driver(&wf_max6690_driver); } static void __exit wf_max6690_sensor_exit(void) { i2c_del_driver(&wf_max6690_driver); } module_init(wf_max6690_sensor_init); module_exit(wf_max6690_sensor_exit); MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>"); MODULE_DESCRIPTION("MAX6690 sensor objects for PowerMac thermal control"); MODULE_LICENSE("GPL");