kbuild: document howto build external modules using several directories
[linux-2.6/verdex.git] / drivers / hwmon / smsc47b397.c
blob2a3e21b5b6b4443a11bc47387a9ea66ebcbb12c3
1 /*
2 smsc47b397.c - Part of lm_sensors, Linux kernel modules
3 for hardware monitoring
5 Supports the SMSC LPC47B397-NC Super-I/O chip.
7 Author/Maintainer: Mark M. Hoffman <mhoffman@lightlink.com>
8 Copyright (C) 2004 Utilitek Systems, Inc.
10 derived in part from smsc47m1.c:
11 Copyright (C) 2002 Mark D. Studebaker <mdsxyz123@yahoo.com>
12 Copyright (C) 2004 Jean Delvare <khali@linux-fr.org>
14 This program is free software; you can redistribute it and/or modify
15 it under the terms of the GNU General Public License as published by
16 the Free Software Foundation; either version 2 of the License, or
17 (at your option) any later version.
19 This program is distributed in the hope that it will be useful,
20 but WITHOUT ANY WARRANTY; without even the implied warranty of
21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 GNU General Public License for more details.
24 You should have received a copy of the GNU General Public License
25 along with this program; if not, write to the Free Software
26 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
29 #include <linux/module.h>
30 #include <linux/slab.h>
31 #include <linux/ioport.h>
32 #include <linux/jiffies.h>
33 #include <linux/i2c.h>
34 #include <linux/i2c-isa.h>
35 #include <linux/hwmon.h>
36 #include <linux/err.h>
37 #include <linux/init.h>
38 #include <asm/io.h>
40 /* Address is autodetected, there is no default value */
41 static unsigned short address;
43 /* Super-I/0 registers and commands */
45 #define REG 0x2e /* The register to read/write */
46 #define VAL 0x2f /* The value to read/write */
48 static inline void superio_outb(int reg, int val)
50 outb(reg, REG);
51 outb(val, VAL);
54 static inline int superio_inb(int reg)
56 outb(reg, REG);
57 return inb(VAL);
60 /* select superio logical device */
61 static inline void superio_select(int ld)
63 superio_outb(0x07, ld);
66 static inline void superio_enter(void)
68 outb(0x55, REG);
71 static inline void superio_exit(void)
73 outb(0xAA, REG);
76 #define SUPERIO_REG_DEVID 0x20
77 #define SUPERIO_REG_DEVREV 0x21
78 #define SUPERIO_REG_BASE_MSB 0x60
79 #define SUPERIO_REG_BASE_LSB 0x61
80 #define SUPERIO_REG_LD8 0x08
82 #define SMSC_EXTENT 0x02
84 /* 0 <= nr <= 3 */
85 static u8 smsc47b397_reg_temp[] = {0x25, 0x26, 0x27, 0x80};
86 #define SMSC47B397_REG_TEMP(nr) (smsc47b397_reg_temp[(nr)])
88 /* 0 <= nr <= 3 */
89 #define SMSC47B397_REG_FAN_LSB(nr) (0x28 + 2 * (nr))
90 #define SMSC47B397_REG_FAN_MSB(nr) (0x29 + 2 * (nr))
92 struct smsc47b397_data {
93 struct i2c_client client;
94 struct class_device *class_dev;
95 struct semaphore lock;
97 struct semaphore update_lock;
98 unsigned long last_updated; /* in jiffies */
99 int valid;
101 /* register values */
102 u16 fan[4];
103 u8 temp[4];
106 static int smsc47b397_read_value(struct i2c_client *client, u8 reg)
108 struct smsc47b397_data *data = i2c_get_clientdata(client);
109 int res;
111 down(&data->lock);
112 outb(reg, client->addr);
113 res = inb_p(client->addr + 1);
114 up(&data->lock);
115 return res;
118 static struct smsc47b397_data *smsc47b397_update_device(struct device *dev)
120 struct i2c_client *client = to_i2c_client(dev);
121 struct smsc47b397_data *data = i2c_get_clientdata(client);
122 int i;
124 down(&data->update_lock);
126 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
127 dev_dbg(&client->dev, "starting device update...\n");
129 /* 4 temperature inputs, 4 fan inputs */
130 for (i = 0; i < 4; i++) {
131 data->temp[i] = smsc47b397_read_value(client,
132 SMSC47B397_REG_TEMP(i));
134 /* must read LSB first */
135 data->fan[i] = smsc47b397_read_value(client,
136 SMSC47B397_REG_FAN_LSB(i));
137 data->fan[i] |= smsc47b397_read_value(client,
138 SMSC47B397_REG_FAN_MSB(i)) << 8;
141 data->last_updated = jiffies;
142 data->valid = 1;
144 dev_dbg(&client->dev, "... device update complete\n");
147 up(&data->update_lock);
149 return data;
152 /* TEMP: 0.001C/bit (-128C to +127C)
153 REG: 1C/bit, two's complement */
154 static int temp_from_reg(u8 reg)
156 return (s8)reg * 1000;
159 /* 0 <= nr <= 3 */
160 static ssize_t show_temp(struct device *dev, char *buf, int nr)
162 struct smsc47b397_data *data = smsc47b397_update_device(dev);
163 return sprintf(buf, "%d\n", temp_from_reg(data->temp[nr]));
166 #define sysfs_temp(num) \
167 static ssize_t show_temp##num(struct device *dev, struct device_attribute *attr, char *buf) \
169 return show_temp(dev, buf, num-1); \
171 static DEVICE_ATTR(temp##num##_input, S_IRUGO, show_temp##num, NULL)
173 sysfs_temp(1);
174 sysfs_temp(2);
175 sysfs_temp(3);
176 sysfs_temp(4);
178 #define device_create_file_temp(client, num) \
179 device_create_file(&client->dev, &dev_attr_temp##num##_input)
181 /* FAN: 1 RPM/bit
182 REG: count of 90kHz pulses / revolution */
183 static int fan_from_reg(u16 reg)
185 return 90000 * 60 / reg;
188 /* 0 <= nr <= 3 */
189 static ssize_t show_fan(struct device *dev, char *buf, int nr)
191 struct smsc47b397_data *data = smsc47b397_update_device(dev);
192 return sprintf(buf, "%d\n", fan_from_reg(data->fan[nr]));
195 #define sysfs_fan(num) \
196 static ssize_t show_fan##num(struct device *dev, struct device_attribute *attr, char *buf) \
198 return show_fan(dev, buf, num-1); \
200 static DEVICE_ATTR(fan##num##_input, S_IRUGO, show_fan##num, NULL)
202 sysfs_fan(1);
203 sysfs_fan(2);
204 sysfs_fan(3);
205 sysfs_fan(4);
207 #define device_create_file_fan(client, num) \
208 device_create_file(&client->dev, &dev_attr_fan##num##_input)
210 static int smsc47b397_detach_client(struct i2c_client *client)
212 struct smsc47b397_data *data = i2c_get_clientdata(client);
213 int err;
215 hwmon_device_unregister(data->class_dev);
217 if ((err = i2c_detach_client(client)))
218 return err;
220 release_region(client->addr, SMSC_EXTENT);
221 kfree(data);
223 return 0;
226 static int smsc47b397_detect(struct i2c_adapter *adapter);
228 static struct i2c_driver smsc47b397_driver = {
229 .owner = THIS_MODULE,
230 .name = "smsc47b397",
231 .attach_adapter = smsc47b397_detect,
232 .detach_client = smsc47b397_detach_client,
235 static int smsc47b397_detect(struct i2c_adapter *adapter)
237 struct i2c_client *new_client;
238 struct smsc47b397_data *data;
239 int err = 0;
241 if (!request_region(address, SMSC_EXTENT, smsc47b397_driver.name)) {
242 dev_err(&adapter->dev, "Region 0x%x already in use!\n",
243 address);
244 return -EBUSY;
247 if (!(data = kzalloc(sizeof(struct smsc47b397_data), GFP_KERNEL))) {
248 err = -ENOMEM;
249 goto error_release;
252 new_client = &data->client;
253 i2c_set_clientdata(new_client, data);
254 new_client->addr = address;
255 init_MUTEX(&data->lock);
256 new_client->adapter = adapter;
257 new_client->driver = &smsc47b397_driver;
258 new_client->flags = 0;
260 strlcpy(new_client->name, "smsc47b397", I2C_NAME_SIZE);
262 init_MUTEX(&data->update_lock);
264 if ((err = i2c_attach_client(new_client)))
265 goto error_free;
267 data->class_dev = hwmon_device_register(&new_client->dev);
268 if (IS_ERR(data->class_dev)) {
269 err = PTR_ERR(data->class_dev);
270 goto error_detach;
273 device_create_file_temp(new_client, 1);
274 device_create_file_temp(new_client, 2);
275 device_create_file_temp(new_client, 3);
276 device_create_file_temp(new_client, 4);
278 device_create_file_fan(new_client, 1);
279 device_create_file_fan(new_client, 2);
280 device_create_file_fan(new_client, 3);
281 device_create_file_fan(new_client, 4);
283 return 0;
285 error_detach:
286 i2c_detach_client(new_client);
287 error_free:
288 kfree(data);
289 error_release:
290 release_region(address, SMSC_EXTENT);
291 return err;
294 static int __init smsc47b397_find(unsigned short *addr)
296 u8 id, rev;
298 superio_enter();
299 id = superio_inb(SUPERIO_REG_DEVID);
301 if ((id != 0x6f) && (id != 0x81)) {
302 superio_exit();
303 return -ENODEV;
306 rev = superio_inb(SUPERIO_REG_DEVREV);
308 superio_select(SUPERIO_REG_LD8);
309 *addr = (superio_inb(SUPERIO_REG_BASE_MSB) << 8)
310 | superio_inb(SUPERIO_REG_BASE_LSB);
312 printk(KERN_INFO "smsc47b397: found SMSC %s "
313 "(base address 0x%04x, revision %u)\n",
314 id == 0x81 ? "SCH5307-NS" : "LPC47B397-NC", *addr, rev);
316 superio_exit();
317 return 0;
320 static int __init smsc47b397_init(void)
322 int ret;
324 if ((ret = smsc47b397_find(&address)))
325 return ret;
327 return i2c_isa_add_driver(&smsc47b397_driver);
330 static void __exit smsc47b397_exit(void)
332 i2c_isa_del_driver(&smsc47b397_driver);
335 MODULE_AUTHOR("Mark M. Hoffman <mhoffman@lightlink.com>");
336 MODULE_DESCRIPTION("SMSC LPC47B397 driver");
337 MODULE_LICENSE("GPL");
339 module_init(smsc47b397_init);
340 module_exit(smsc47b397_exit);