diff options
Diffstat (limited to 'drivers/macintosh/windfarm_max6690_sensor.c')
| -rw-r--r-- | drivers/macintosh/windfarm_max6690_sensor.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/drivers/macintosh/windfarm_max6690_sensor.c b/drivers/macintosh/windfarm_max6690_sensor.c new file mode 100644 index 0000000..5b9ad6ca --- /dev/null +++ b/drivers/macintosh/windfarm_max6690_sensor.c @@ -0,0 +1,169 @@ +/* + * 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 <linux/i2c-dev.h> +#include <asm/prom.h> +#include <asm/pmac_low_i2c.h> + +#include "windfarm.h" + +#define VERSION "0.1" + +/* 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 = "u4-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; + u32 *reg; + + 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) { + if (!device_is_compatible(dev, "max6690")) + continue; + loc = get_property(dev, "hwsensor-location", NULL); + reg = (u32 *) get_property(dev, "reg", NULL); + if (!loc || !reg) + continue; + printk("found max6690, loc=%s reg=%x\n", loc, *reg); + if (strcmp(loc, "BACKSIDE")) + continue; + wf_max6690_create(adapter, *reg); + } + + 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) +{ + 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"); |