/* * Windfarm PowerMac thermal control. LM75 sensor * * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp. * <benh@kernel.crashing.org> * * Released under the term of the GNU GPL v2. */ #include <linux/types.h> #include <linux/errno.h> #include <linux/kernel.h> #include <linux/delay.h> #include <linux/slab.h> #include <linux/init.h> #include <linux/wait.h> #include <linux/i2c.h> #include <linux/i2c-dev.h> #include <asm/prom.h> #include <asm/machdep.h> #include <asm/io.h> #include <asm/system.h> #include <asm/sections.h> #include <asm/pmac_low_i2c.h> #include "windfarm.h" #define VERSION "0.1" #undef DEBUG #ifdef DEBUG #define DBG(args...) printk(args) #else #define DBG(args...) do { } while(0) #endif struct wf_lm75_sensor { int ds1775 : 1; int inited : 1; struct i2c_client i2c; struct wf_sensor sens; }; #define wf_to_lm75(c) container_of(c, struct wf_lm75_sensor, sens) #define i2c_to_lm75(c) container_of(c, struct wf_lm75_sensor, i2c) static int wf_lm75_attach(struct i2c_adapter *adapter); static int wf_lm75_detach(struct i2c_client *client); static struct i2c_driver wf_lm75_driver = { .driver = { .name = "wf_lm75", }, .attach_adapter = wf_lm75_attach, .detach_client = wf_lm75_detach, }; static int wf_lm75_get(struct wf_sensor *sr, s32 *value) { struct wf_lm75_sensor *lm = wf_to_lm75(sr); s32 data; if (lm->i2c.adapter == NULL) return -ENODEV; /* Init chip if necessary */ if (!lm->inited) { u8 cfg_new, cfg = (u8)i2c_smbus_read_byte_data(&lm->i2c, 1); DBG("wf_lm75: Initializing %s, cfg was: %02x\n", sr->name, cfg); /* clear shutdown bit, keep other settings as left by * the firmware for now */ cfg_new = cfg & ~0x01; i2c_smbus_write_byte_data(&lm->i2c, 1, cfg_new); lm->inited = 1; /* If we just powered it up, let's wait 200 ms */ msleep(200); } /* Read temperature register */ data = (s32)le16_to_cpu(i2c_smbus_read_word_data(&lm->i2c, 0)); data <<= 8; *value = data; return 0; } static void wf_lm75_release(struct wf_sensor *sr) { struct wf_lm75_sensor *lm = wf_to_lm75(sr); /* check if client is registered and detach from i2c */ if (lm->i2c.adapter) { i2c_detach_client(&lm->i2c); lm->i2c.adapter = NULL; } kfree(lm); } static struct wf_sensor_ops wf_lm75_ops = { .get_value = wf_lm75_get, .release = wf_lm75_release, .owner = THIS_MODULE, }; static struct wf_lm75_sensor *wf_lm75_create(struct i2c_adapter *adapter, u8 addr, int ds1775, const char *loc) { struct wf_lm75_sensor *lm; DBG("wf_lm75: creating %s device at address 0x%02x\n", ds1775 ? "ds1775" : "lm75", addr); lm = kmalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL); if (lm == NULL) return NULL; memset(lm, 0, sizeof(struct wf_lm75_sensor)); /* Usual rant about sensor names not beeing very consistent in * the device-tree, oh well ... * Add more entries below as you deal with more setups */ if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY")) lm->sens.name = "hd-temp"; else goto fail; lm->inited = 0; lm->sens.ops = &wf_lm75_ops; lm->ds1775 = ds1775; lm->i2c.addr = (addr >> 1) & 0x7f; lm->i2c.adapter = adapter; lm->i2c.driver = &wf_lm75_driver; strncpy(lm->i2c.name, lm->sens.name, I2C_NAME_SIZE-1); if (i2c_attach_client(&lm->i2c)) { printk(KERN_ERR "windfarm: failed to attach %s %s to i2c\n", ds1775 ? "ds1775" : "lm75", lm->i2c.name); goto fail; } if (wf_register_sensor(&lm->sens)) { i2c_detach_client(&lm->i2c); goto fail; } return lm; fail: kfree(lm); return NULL; } static int wf_lm75_attach(struct i2c_adapter *adapter) { struct device_node *busnode, *dev; struct pmac_i2c_bus *bus; DBG("wf_lm75: adapter %s detected\n", adapter->name); bus = pmac_i2c_adapter_to_bus(adapter); if (bus == NULL) return -ENODEV; busnode = pmac_i2c_get_bus_node(bus); DBG("wf_lm75: bus found, looking for device...\n"); /* Now look for lm75(s) in there */ for (dev = NULL; (dev = of_get_next_child(busnode, dev)) != NULL;) { const char *loc = get_property(dev, "hwsensor-location", NULL); u32 *reg = (u32 *)get_property(dev, "reg", NULL); DBG(" dev: %s... (loc: %p, reg: %p)\n", dev->name, loc, reg); if (loc == NULL || reg == NULL) continue; /* real lm75 */ if (device_is_compatible(dev, "lm75")) wf_lm75_create(adapter, *reg, 0, loc); /* ds1775 (compatible, better resolution */ else if (device_is_compatible(dev, "ds1775")) wf_lm75_create(adapter, *reg, 1, loc); } return 0; } static int wf_lm75_detach(struct i2c_client *client) { struct wf_lm75_sensor *lm = i2c_to_lm75(client); DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name); /* Mark client detached */ lm->i2c.adapter = NULL; /* release sensor */ wf_unregister_sensor(&lm->sens); return 0; } static int __init wf_lm75_sensor_init(void) { return i2c_add_driver(&wf_lm75_driver); } static void __exit wf_lm75_sensor_exit(void) { i2c_del_driver(&wf_lm75_driver); } module_init(wf_lm75_sensor_init); module_exit(wf_lm75_sensor_exit); MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control"); MODULE_LICENSE("GPL");