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1/*
2 * atxp1.c - kernel module for setting CPU VID and general purpose
3 * I/Os using the Attansic ATXP1 chip.
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18 *
19 */
20
21#include <linux/kernel.h>
22#include <linux/init.h>
23#include <linux/module.h>
24#include <linux/jiffies.h>
25#include <linux/i2c.h>
26#include <linux/hwmon.h>
27#include <linux/hwmon-vid.h>
28#include <linux/err.h>
29#include <linux/mutex.h>
30#include <linux/sysfs.h>
31#include <linux/slab.h>
32
33MODULE_LICENSE("GPL");
34MODULE_DESCRIPTION("System voltages control via Attansic ATXP1");
35MODULE_VERSION("0.6.3");
36MODULE_AUTHOR("Sebastian Witt <se.witt@gmx.net>");
37
38#define ATXP1_VID 0x00
39#define ATXP1_CVID 0x01
40#define ATXP1_GPIO1 0x06
41#define ATXP1_GPIO2 0x0a
42#define ATXP1_VIDENA 0x20
43#define ATXP1_VIDMASK 0x1f
44#define ATXP1_GPIO1MASK 0x0f
45
46static const unsigned short normal_i2c[] = { 0x37, 0x4e, I2C_CLIENT_END };
47
48static int atxp1_probe(struct i2c_client *client,
49 const struct i2c_device_id *id);
50static int atxp1_remove(struct i2c_client *client);
51static struct atxp1_data *atxp1_update_device(struct device *dev);
52static int atxp1_detect(struct i2c_client *client, struct i2c_board_info *info);
53
54static const struct i2c_device_id atxp1_id[] = {
55 { "atxp1", 0 },
56 { }
57};
58MODULE_DEVICE_TABLE(i2c, atxp1_id);
59
60static struct i2c_driver atxp1_driver = {
61 .class = I2C_CLASS_HWMON,
62 .driver = {
63 .name = "atxp1",
64 },
65 .probe = atxp1_probe,
66 .remove = atxp1_remove,
67 .id_table = atxp1_id,
68 .detect = atxp1_detect,
69 .address_list = normal_i2c,
70};
71
72struct atxp1_data {
73 struct device *hwmon_dev;
74 struct mutex update_lock;
75 unsigned long last_updated;
76 u8 valid;
77 struct {
78 u8 vid; /* VID output register */
79 u8 cpu_vid; /* VID input from CPU */
80 u8 gpio1; /* General purpose I/O register 1 */
81 u8 gpio2; /* General purpose I/O register 2 */
82 } reg;
83 u8 vrm; /* Detected CPU VRM */
84};
85
86static struct atxp1_data *atxp1_update_device(struct device *dev)
87{
88 struct i2c_client *client;
89 struct atxp1_data *data;
90
91 client = to_i2c_client(dev);
92 data = i2c_get_clientdata(client);
93
94 mutex_lock(&data->update_lock);
95
96 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
97
98 /* Update local register data */
99 data->reg.vid = i2c_smbus_read_byte_data(client, ATXP1_VID);
100 data->reg.cpu_vid = i2c_smbus_read_byte_data(client,
101 ATXP1_CVID);
102 data->reg.gpio1 = i2c_smbus_read_byte_data(client, ATXP1_GPIO1);
103 data->reg.gpio2 = i2c_smbus_read_byte_data(client, ATXP1_GPIO2);
104
105 data->valid = 1;
106 }
107
108 mutex_unlock(&data->update_lock);
109
110 return data;
111}
112
113/* sys file functions for cpu0_vid */
114static ssize_t atxp1_showvcore(struct device *dev,
115 struct device_attribute *attr, char *buf)
116{
117 int size;
118 struct atxp1_data *data;
119
120 data = atxp1_update_device(dev);
121
122 size = sprintf(buf, "%d\n", vid_from_reg(data->reg.vid & ATXP1_VIDMASK,
123 data->vrm));
124
125 return size;
126}
127
128static ssize_t atxp1_storevcore(struct device *dev,
129 struct device_attribute *attr,
130 const char *buf, size_t count)
131{
132 struct atxp1_data *data;
133 struct i2c_client *client;
134 int vid, cvid;
135 unsigned long vcore;
136 int err;
137
138 client = to_i2c_client(dev);
139 data = atxp1_update_device(dev);
140
141 err = kstrtoul(buf, 10, &vcore);
142 if (err)
143 return err;
144
145 vcore /= 25;
146 vcore *= 25;
147
148 /* Calculate VID */
149 vid = vid_to_reg(vcore, data->vrm);
150
151 if (vid < 0) {
152 dev_err(dev, "VID calculation failed.\n");
153 return -1;
154 }
155
156 /*
157 * If output enabled, use control register value.
158 * Otherwise original CPU VID
159 */
160 if (data->reg.vid & ATXP1_VIDENA)
161 cvid = data->reg.vid & ATXP1_VIDMASK;
162 else
163 cvid = data->reg.cpu_vid;
164
165 /* Nothing changed, aborting */
166 if (vid == cvid)
167 return count;
168
169 dev_dbg(dev, "Setting VCore to %d mV (0x%02x)\n", (int)vcore, vid);
170
171 /* Write every 25 mV step to increase stability */
172 if (cvid > vid) {
173 for (; cvid >= vid; cvid--)
174 i2c_smbus_write_byte_data(client,
175 ATXP1_VID, cvid | ATXP1_VIDENA);
176 } else {
177 for (; cvid <= vid; cvid++)
178 i2c_smbus_write_byte_data(client,
179 ATXP1_VID, cvid | ATXP1_VIDENA);
180 }
181
182 data->valid = 0;
183
184 return count;
185}
186
187/*
188 * CPU core reference voltage
189 * unit: millivolt
190 */
191static DEVICE_ATTR(cpu0_vid, S_IRUGO | S_IWUSR, atxp1_showvcore,
192 atxp1_storevcore);
193
194/* sys file functions for GPIO1 */
195static ssize_t atxp1_showgpio1(struct device *dev,
196 struct device_attribute *attr, char *buf)
197{
198 int size;
199 struct atxp1_data *data;
200
201 data = atxp1_update_device(dev);
202
203 size = sprintf(buf, "0x%02x\n", data->reg.gpio1 & ATXP1_GPIO1MASK);
204
205 return size;
206}
207
208static ssize_t atxp1_storegpio1(struct device *dev,
209 struct device_attribute *attr, const char *buf,
210 size_t count)
211{
212 struct atxp1_data *data;
213 struct i2c_client *client;
214 unsigned long value;
215 int err;
216
217 client = to_i2c_client(dev);
218 data = atxp1_update_device(dev);
219
220 err = kstrtoul(buf, 16, &value);
221 if (err)
222 return err;
223
224 value &= ATXP1_GPIO1MASK;
225
226 if (value != (data->reg.gpio1 & ATXP1_GPIO1MASK)) {
227 dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value);
228
229 i2c_smbus_write_byte_data(client, ATXP1_GPIO1, value);
230
231 data->valid = 0;
232 }
233
234 return count;
235}
236
237/*
238 * GPIO1 data register
239 * unit: Four bit as hex (e.g. 0x0f)
240 */
241static DEVICE_ATTR(gpio1, S_IRUGO | S_IWUSR, atxp1_showgpio1, atxp1_storegpio1);
242
243/* sys file functions for GPIO2 */
244static ssize_t atxp1_showgpio2(struct device *dev,
245 struct device_attribute *attr, char *buf)
246{
247 int size;
248 struct atxp1_data *data;
249
250 data = atxp1_update_device(dev);
251
252 size = sprintf(buf, "0x%02x\n", data->reg.gpio2);
253
254 return size;
255}
256
257static ssize_t atxp1_storegpio2(struct device *dev,
258 struct device_attribute *attr,
259 const char *buf, size_t count)
260{
261 struct atxp1_data *data = atxp1_update_device(dev);
262 struct i2c_client *client = to_i2c_client(dev);
263 unsigned long value;
264 int err;
265
266 err = kstrtoul(buf, 16, &value);
267 if (err)
268 return err;
269 value &= 0xff;
270
271 if (value != data->reg.gpio2) {
272 dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value);
273
274 i2c_smbus_write_byte_data(client, ATXP1_GPIO2, value);
275
276 data->valid = 0;
277 }
278
279 return count;
280}
281
282/*
283 * GPIO2 data register
284 * unit: Eight bit as hex (e.g. 0xff)
285 */
286static DEVICE_ATTR(gpio2, S_IRUGO | S_IWUSR, atxp1_showgpio2, atxp1_storegpio2);
287
288static struct attribute *atxp1_attributes[] = {
289 &dev_attr_gpio1.attr,
290 &dev_attr_gpio2.attr,
291 &dev_attr_cpu0_vid.attr,
292 NULL
293};
294
295static const struct attribute_group atxp1_group = {
296 .attrs = atxp1_attributes,
297};
298
299
300/* Return 0 if detection is successful, -ENODEV otherwise */
301static int atxp1_detect(struct i2c_client *new_client,
302 struct i2c_board_info *info)
303{
304 struct i2c_adapter *adapter = new_client->adapter;
305
306 u8 temp;
307
308 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
309 return -ENODEV;
310
311 /* Detect ATXP1, checking if vendor ID registers are all zero */
312 if (!((i2c_smbus_read_byte_data(new_client, 0x3e) == 0) &&
313 (i2c_smbus_read_byte_data(new_client, 0x3f) == 0) &&
314 (i2c_smbus_read_byte_data(new_client, 0xfe) == 0) &&
315 (i2c_smbus_read_byte_data(new_client, 0xff) == 0)))
316 return -ENODEV;
317
318 /*
319 * No vendor ID, now checking if registers 0x10,0x11 (non-existent)
320 * showing the same as register 0x00
321 */
322 temp = i2c_smbus_read_byte_data(new_client, 0x00);
323
324 if (!((i2c_smbus_read_byte_data(new_client, 0x10) == temp) &&
325 (i2c_smbus_read_byte_data(new_client, 0x11) == temp)))
326 return -ENODEV;
327
328 /* Get VRM */
329 temp = vid_which_vrm();
330
331 if ((temp != 90) && (temp != 91)) {
332 dev_err(&adapter->dev, "atxp1: Not supporting VRM %d.%d\n",
333 temp / 10, temp % 10);
334 return -ENODEV;
335 }
336
337 strlcpy(info->type, "atxp1", I2C_NAME_SIZE);
338
339 return 0;
340}
341
342static int atxp1_probe(struct i2c_client *new_client,
343 const struct i2c_device_id *id)
344{
345 struct atxp1_data *data;
346 int err;
347
348 data = kzalloc(sizeof(struct atxp1_data), GFP_KERNEL);
349 if (!data) {
350 err = -ENOMEM;
351 goto exit;
352 }
353
354 /* Get VRM */
355 data->vrm = vid_which_vrm();
356
357 i2c_set_clientdata(new_client, data);
358 data->valid = 0;
359
360 mutex_init(&data->update_lock);
361
362 /* Register sysfs hooks */
363 err = sysfs_create_group(&new_client->dev.kobj, &atxp1_group);
364 if (err)
365 goto exit_free;
366
367 data->hwmon_dev = hwmon_device_register(&new_client->dev);
368 if (IS_ERR(data->hwmon_dev)) {
369 err = PTR_ERR(data->hwmon_dev);
370 goto exit_remove_files;
371 }
372
373 dev_info(&new_client->dev, "Using VRM: %d.%d\n",
374 data->vrm / 10, data->vrm % 10);
375
376 return 0;
377
378exit_remove_files:
379 sysfs_remove_group(&new_client->dev.kobj, &atxp1_group);
380exit_free:
381 kfree(data);
382exit:
383 return err;
384};
385
386static int atxp1_remove(struct i2c_client *client)
387{
388 struct atxp1_data *data = i2c_get_clientdata(client);
389
390 hwmon_device_unregister(data->hwmon_dev);
391 sysfs_remove_group(&client->dev.kobj, &atxp1_group);
392
393 kfree(data);
394
395 return 0;
396};
397
398module_i2c_driver(atxp1_driver);