diff options
Diffstat (limited to 'drivers/macintosh/windfarm_lm75_sensor.c')
| -rw-r--r-- | drivers/macintosh/windfarm_lm75_sensor.c | 263 |
1 files changed, 263 insertions, 0 deletions
diff --git a/drivers/macintosh/windfarm_lm75_sensor.c b/drivers/macintosh/windfarm_lm75_sensor.c new file mode 100644 index 00000000000..a0a41ad0f2b --- /dev/null +++ b/drivers/macintosh/windfarm_lm75_sensor.c @@ -0,0 +1,263 @@ +/* + * 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 "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 = { + .owner = THIS_MODULE, + .name = "wf_lm75", + .flags = I2C_DF_NOTIFY, + .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) +{ + u8 bus_id; + struct device_node *smu, *bus, *dev; + + /* We currently only deal with LM75's hanging off the SMU + * i2c busses. If we extend that driver to other/older + * machines, we should split this function into SMU-i2c, + * keywest-i2c, PMU-i2c, ... + */ + + DBG("wf_lm75: adapter %s detected\n", adapter->name); + + if (strncmp(adapter->name, "smu-i2c-", 8) != 0) + return 0; + smu = of_find_node_by_type(NULL, "smu"); + if (smu == NULL) + return 0; + + /* Look for the bus in the device-tree */ + bus_id = (u8)simple_strtoul(adapter->name + 8, NULL, 16); + + DBG("wf_lm75: bus ID is %x\n", bus_id); + + /* Look for sensors subdir */ + for (bus = NULL; + (bus = of_get_next_child(smu, bus)) != NULL;) { + u32 *reg; + + if (strcmp(bus->name, "i2c")) + continue; + reg = (u32 *)get_property(bus, "reg", NULL); + if (reg == NULL) + continue; + if (bus_id == *reg) + break; + } + of_node_put(smu); + if (bus == NULL) { + printk(KERN_WARNING "windfarm: SMU i2c bus 0x%x not found" + " in device-tree !\n", bus_id); + return 0; + } + + DBG("wf_lm75: bus found, looking for device...\n"); + + /* Now look for lm75(s) in there */ + for (dev = NULL; + (dev = of_get_next_child(bus, 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); + } + + of_node_put(bus); + + 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) +{ + int rc; + + rc = i2c_add_driver(&wf_lm75_driver); + if (rc < 0) + return rc; + return 0; +} + +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"); + |