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ics932s401.c
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1 /*
2  * A driver for the Integrated Circuits ICS932S401
3  * Copyright (C) 2008 IBM
4  *
5  * Author: Darrick J. Wong <[email protected]>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20  */
21 
22 #include <linux/module.h>
23 #include <linux/jiffies.h>
24 #include <linux/i2c.h>
25 #include <linux/err.h>
26 #include <linux/mutex.h>
27 #include <linux/delay.h>
28 #include <linux/log2.h>
29 #include <linux/slab.h>
30 
31 /* Addresses to scan */
32 static const unsigned short normal_i2c[] = { 0x69, I2C_CLIENT_END };
33 
34 /* ICS932S401 registers */
35 #define ICS932S401_REG_CFG2 0x01
36 #define ICS932S401_CFG1_SPREAD 0x01
37 #define ICS932S401_REG_CFG7 0x06
38 #define ICS932S401_FS_MASK 0x07
39 #define ICS932S401_REG_VENDOR_REV 0x07
40 #define ICS932S401_VENDOR 1
41 #define ICS932S401_VENDOR_MASK 0x0F
42 #define ICS932S401_REV 4
43 #define ICS932S401_REV_SHIFT 4
44 #define ICS932S401_REG_DEVICE 0x09
45 #define ICS932S401_DEVICE 11
46 #define ICS932S401_REG_CTRL 0x0A
47 #define ICS932S401_MN_ENABLED 0x80
48 #define ICS932S401_CPU_ALT 0x04
49 #define ICS932S401_SRC_ALT 0x08
50 #define ICS932S401_REG_CPU_M_CTRL 0x0B
51 #define ICS932S401_M_MASK 0x3F
52 #define ICS932S401_REG_CPU_N_CTRL 0x0C
53 #define ICS932S401_REG_CPU_SPREAD1 0x0D
54 #define ICS932S401_REG_CPU_SPREAD2 0x0E
55 #define ICS932S401_SPREAD_MASK 0x7FFF
56 #define ICS932S401_REG_SRC_M_CTRL 0x0F
57 #define ICS932S401_REG_SRC_N_CTRL 0x10
58 #define ICS932S401_REG_SRC_SPREAD1 0x11
59 #define ICS932S401_REG_SRC_SPREAD2 0x12
60 #define ICS932S401_REG_CPU_DIVISOR 0x13
61 #define ICS932S401_CPU_DIVISOR_SHIFT 4
62 #define ICS932S401_REG_PCISRC_DIVISOR 0x14
63 #define ICS932S401_SRC_DIVISOR_MASK 0x0F
64 #define ICS932S401_PCI_DIVISOR_SHIFT 4
65 
66 /* Base clock is 14.318MHz */
67 #define BASE_CLOCK 14318
68 
69 #define NUM_REGS 21
70 #define NUM_MIRRORED_REGS 15
71 
72 static int regs_to_copy[NUM_MIRRORED_REGS] = {
73  ICS932S401_REG_CFG2,
74  ICS932S401_REG_CFG7,
75  ICS932S401_REG_VENDOR_REV,
76  ICS932S401_REG_DEVICE,
77  ICS932S401_REG_CTRL,
78  ICS932S401_REG_CPU_M_CTRL,
79  ICS932S401_REG_CPU_N_CTRL,
80  ICS932S401_REG_CPU_SPREAD1,
81  ICS932S401_REG_CPU_SPREAD2,
82  ICS932S401_REG_SRC_M_CTRL,
83  ICS932S401_REG_SRC_N_CTRL,
84  ICS932S401_REG_SRC_SPREAD1,
85  ICS932S401_REG_SRC_SPREAD2,
86  ICS932S401_REG_CPU_DIVISOR,
87  ICS932S401_REG_PCISRC_DIVISOR,
88 };
89 
90 /* How often do we reread sensors values? (In jiffies) */
91 #define SENSOR_REFRESH_INTERVAL (2 * HZ)
92 
93 /* How often do we reread sensor limit values? (In jiffies) */
94 #define LIMIT_REFRESH_INTERVAL (60 * HZ)
95 
96 struct ics932s401_data {
97  struct attribute_group attrs;
98  struct mutex lock;
99  char sensors_valid;
100  unsigned long sensors_last_updated; /* In jiffies */
101 
102  u8 regs[NUM_REGS];
103 };
104 
105 static int ics932s401_probe(struct i2c_client *client,
106  const struct i2c_device_id *id);
107 static int ics932s401_detect(struct i2c_client *client,
108  struct i2c_board_info *info);
109 static int ics932s401_remove(struct i2c_client *client);
110 
111 static const struct i2c_device_id ics932s401_id[] = {
112  { "ics932s401", 0 },
113  { }
114 };
115 MODULE_DEVICE_TABLE(i2c, ics932s401_id);
116 
117 static struct i2c_driver ics932s401_driver = {
118  .class = I2C_CLASS_HWMON,
119  .driver = {
120  .name = "ics932s401",
121  },
122  .probe = ics932s401_probe,
123  .remove = ics932s401_remove,
124  .id_table = ics932s401_id,
125  .detect = ics932s401_detect,
126  .address_list = normal_i2c,
127 };
128 
129 static struct ics932s401_data *ics932s401_update_device(struct device *dev)
130 {
131  struct i2c_client *client = to_i2c_client(dev);
132  struct ics932s401_data *data = i2c_get_clientdata(client);
133  unsigned long local_jiffies = jiffies;
134  int i, temp;
135 
136  mutex_lock(&data->lock);
137  if (time_before(local_jiffies, data->sensors_last_updated +
138  SENSOR_REFRESH_INTERVAL)
139  && data->sensors_valid)
140  goto out;
141 
142  /*
143  * Each register must be read as a word and then right shifted 8 bits.
144  * Not really sure why this is; setting the "byte count programming"
145  * register to 1 does not fix this problem.
146  */
147  for (i = 0; i < NUM_MIRRORED_REGS; i++) {
148  temp = i2c_smbus_read_word_data(client, regs_to_copy[i]);
149  data->regs[regs_to_copy[i]] = temp >> 8;
150  }
151 
152  data->sensors_last_updated = local_jiffies;
153  data->sensors_valid = 1;
154 
155 out:
156  mutex_unlock(&data->lock);
157  return data;
158 }
159 
160 static ssize_t show_spread_enabled(struct device *dev,
161  struct device_attribute *devattr,
162  char *buf)
163 {
164  struct ics932s401_data *data = ics932s401_update_device(dev);
165 
166  if (data->regs[ICS932S401_REG_CFG2] & ICS932S401_CFG1_SPREAD)
167  return sprintf(buf, "1\n");
168 
169  return sprintf(buf, "0\n");
170 }
171 
172 /* bit to cpu khz map */
173 static const int fs_speeds[] = {
174  266666,
175  133333,
176  200000,
177  166666,
178  333333,
179  100000,
180  400000,
181  0,
182 };
183 
184 /* clock divisor map */
185 static const int divisors[] = {2, 3, 5, 15, 4, 6, 10, 30, 8, 12, 20, 60, 16,
186  24, 40, 120};
187 
188 /* Calculate CPU frequency from the M/N registers. */
189 static int calculate_cpu_freq(struct ics932s401_data *data)
190 {
191  int m, n, freq;
192 
193  m = data->regs[ICS932S401_REG_CPU_M_CTRL] & ICS932S401_M_MASK;
194  n = data->regs[ICS932S401_REG_CPU_N_CTRL];
195 
196  /* Pull in bits 8 & 9 from the M register */
197  n |= ((int)data->regs[ICS932S401_REG_CPU_M_CTRL] & 0x80) << 1;
198  n |= ((int)data->regs[ICS932S401_REG_CPU_M_CTRL] & 0x40) << 3;
199 
200  freq = BASE_CLOCK * (n + 8) / (m + 2);
201  freq /= divisors[data->regs[ICS932S401_REG_CPU_DIVISOR] >>
202  ICS932S401_CPU_DIVISOR_SHIFT];
203 
204  return freq;
205 }
206 
207 static ssize_t show_cpu_clock(struct device *dev,
208  struct device_attribute *devattr,
209  char *buf)
210 {
211  struct ics932s401_data *data = ics932s401_update_device(dev);
212 
213  return sprintf(buf, "%d\n", calculate_cpu_freq(data));
214 }
215 
216 static ssize_t show_cpu_clock_sel(struct device *dev,
217  struct device_attribute *devattr,
218  char *buf)
219 {
220  struct ics932s401_data *data = ics932s401_update_device(dev);
221  int freq;
222 
223  if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
224  freq = calculate_cpu_freq(data);
225  else {
226  /* Freq is neatly wrapped up for us */
227  int fid = data->regs[ICS932S401_REG_CFG7] & ICS932S401_FS_MASK;
228  freq = fs_speeds[fid];
229  if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_CPU_ALT) {
230  switch (freq) {
231  case 166666:
232  freq = 160000;
233  break;
234  case 333333:
235  freq = 320000;
236  break;
237  }
238  }
239  }
240 
241  return sprintf(buf, "%d\n", freq);
242 }
243 
244 /* Calculate SRC frequency from the M/N registers. */
245 static int calculate_src_freq(struct ics932s401_data *data)
246 {
247  int m, n, freq;
248 
249  m = data->regs[ICS932S401_REG_SRC_M_CTRL] & ICS932S401_M_MASK;
250  n = data->regs[ICS932S401_REG_SRC_N_CTRL];
251 
252  /* Pull in bits 8 & 9 from the M register */
253  n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x80) << 1;
254  n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x40) << 3;
255 
256  freq = BASE_CLOCK * (n + 8) / (m + 2);
257  freq /= divisors[data->regs[ICS932S401_REG_PCISRC_DIVISOR] &
258  ICS932S401_SRC_DIVISOR_MASK];
259 
260  return freq;
261 }
262 
263 static ssize_t show_src_clock(struct device *dev,
264  struct device_attribute *devattr,
265  char *buf)
266 {
267  struct ics932s401_data *data = ics932s401_update_device(dev);
268 
269  return sprintf(buf, "%d\n", calculate_src_freq(data));
270 }
271 
272 static ssize_t show_src_clock_sel(struct device *dev,
273  struct device_attribute *devattr,
274  char *buf)
275 {
276  struct ics932s401_data *data = ics932s401_update_device(dev);
277  int freq;
278 
279  if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
280  freq = calculate_src_freq(data);
281  else
282  /* Freq is neatly wrapped up for us */
283  if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_CPU_ALT &&
284  data->regs[ICS932S401_REG_CTRL] & ICS932S401_SRC_ALT)
285  freq = 96000;
286  else
287  freq = 100000;
288 
289  return sprintf(buf, "%d\n", freq);
290 }
291 
292 /* Calculate PCI frequency from the SRC M/N registers. */
293 static int calculate_pci_freq(struct ics932s401_data *data)
294 {
295  int m, n, freq;
296 
297  m = data->regs[ICS932S401_REG_SRC_M_CTRL] & ICS932S401_M_MASK;
298  n = data->regs[ICS932S401_REG_SRC_N_CTRL];
299 
300  /* Pull in bits 8 & 9 from the M register */
301  n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x80) << 1;
302  n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x40) << 3;
303 
304  freq = BASE_CLOCK * (n + 8) / (m + 2);
305  freq /= divisors[data->regs[ICS932S401_REG_PCISRC_DIVISOR] >>
306  ICS932S401_PCI_DIVISOR_SHIFT];
307 
308  return freq;
309 }
310 
311 static ssize_t show_pci_clock(struct device *dev,
312  struct device_attribute *devattr,
313  char *buf)
314 {
315  struct ics932s401_data *data = ics932s401_update_device(dev);
316 
317  return sprintf(buf, "%d\n", calculate_pci_freq(data));
318 }
319 
320 static ssize_t show_pci_clock_sel(struct device *dev,
321  struct device_attribute *devattr,
322  char *buf)
323 {
324  struct ics932s401_data *data = ics932s401_update_device(dev);
325  int freq;
326 
327  if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
328  freq = calculate_pci_freq(data);
329  else
330  freq = 33333;
331 
332  return sprintf(buf, "%d\n", freq);
333 }
334 
335 static ssize_t show_value(struct device *dev,
336  struct device_attribute *devattr,
337  char *buf);
338 
339 static ssize_t show_spread(struct device *dev,
340  struct device_attribute *devattr,
341  char *buf);
342 
343 static DEVICE_ATTR(spread_enabled, S_IRUGO, show_spread_enabled, NULL);
344 static DEVICE_ATTR(cpu_clock_selection, S_IRUGO, show_cpu_clock_sel, NULL);
345 static DEVICE_ATTR(cpu_clock, S_IRUGO, show_cpu_clock, NULL);
346 static DEVICE_ATTR(src_clock_selection, S_IRUGO, show_src_clock_sel, NULL);
347 static DEVICE_ATTR(src_clock, S_IRUGO, show_src_clock, NULL);
348 static DEVICE_ATTR(pci_clock_selection, S_IRUGO, show_pci_clock_sel, NULL);
349 static DEVICE_ATTR(pci_clock, S_IRUGO, show_pci_clock, NULL);
350 static DEVICE_ATTR(usb_clock, S_IRUGO, show_value, NULL);
351 static DEVICE_ATTR(ref_clock, S_IRUGO, show_value, NULL);
352 static DEVICE_ATTR(cpu_spread, S_IRUGO, show_spread, NULL);
353 static DEVICE_ATTR(src_spread, S_IRUGO, show_spread, NULL);
354 
355 static struct attribute *ics932s401_attr[] =
356 {
357  &dev_attr_spread_enabled.attr,
358  &dev_attr_cpu_clock_selection.attr,
359  &dev_attr_cpu_clock.attr,
360  &dev_attr_src_clock_selection.attr,
361  &dev_attr_src_clock.attr,
362  &dev_attr_pci_clock_selection.attr,
363  &dev_attr_pci_clock.attr,
364  &dev_attr_usb_clock.attr,
365  &dev_attr_ref_clock.attr,
366  &dev_attr_cpu_spread.attr,
367  &dev_attr_src_spread.attr,
368  NULL
369 };
370 
371 static ssize_t show_value(struct device *dev,
372  struct device_attribute *devattr,
373  char *buf)
374 {
375  int x;
376 
377  if (devattr == &dev_attr_usb_clock)
378  x = 48000;
379  else if (devattr == &dev_attr_ref_clock)
380  x = BASE_CLOCK;
381  else
382  BUG();
383 
384  return sprintf(buf, "%d\n", x);
385 }
386 
387 static ssize_t show_spread(struct device *dev,
388  struct device_attribute *devattr,
389  char *buf)
390 {
391  struct ics932s401_data *data = ics932s401_update_device(dev);
392  int reg;
393  unsigned long val;
394 
395  if (!(data->regs[ICS932S401_REG_CFG2] & ICS932S401_CFG1_SPREAD))
396  return sprintf(buf, "0%%\n");
397 
398  if (devattr == &dev_attr_src_spread)
399  reg = ICS932S401_REG_SRC_SPREAD1;
400  else if (devattr == &dev_attr_cpu_spread)
401  reg = ICS932S401_REG_CPU_SPREAD1;
402  else
403  BUG();
404 
405  val = data->regs[reg] | (data->regs[reg + 1] << 8);
406  val &= ICS932S401_SPREAD_MASK;
407 
408  /* Scale 0..2^14 to -0.5. */
409  val = 500000 * val / 16384;
410  return sprintf(buf, "-0.%lu%%\n", val);
411 }
412 
413 /* Return 0 if detection is successful, -ENODEV otherwise */
414 static int ics932s401_detect(struct i2c_client *client,
415  struct i2c_board_info *info)
416 {
417  struct i2c_adapter *adapter = client->adapter;
418  int vendor, device, revision;
419 
420  if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
421  return -ENODEV;
422 
423  vendor = i2c_smbus_read_word_data(client, ICS932S401_REG_VENDOR_REV);
424  vendor >>= 8;
425  revision = vendor >> ICS932S401_REV_SHIFT;
426  vendor &= ICS932S401_VENDOR_MASK;
427  if (vendor != ICS932S401_VENDOR)
428  return -ENODEV;
429 
430  device = i2c_smbus_read_word_data(client, ICS932S401_REG_DEVICE);
431  device >>= 8;
432  if (device != ICS932S401_DEVICE)
433  return -ENODEV;
434 
435  if (revision != ICS932S401_REV)
436  dev_info(&adapter->dev, "Unknown revision %d\n", revision);
437 
438  strlcpy(info->type, "ics932s401", I2C_NAME_SIZE);
439 
440  return 0;
441 }
442 
443 static int ics932s401_probe(struct i2c_client *client,
444  const struct i2c_device_id *id)
445 {
446  struct ics932s401_data *data;
447  int err;
448 
449  data = kzalloc(sizeof(struct ics932s401_data), GFP_KERNEL);
450  if (!data) {
451  err = -ENOMEM;
452  goto exit;
453  }
454 
455  i2c_set_clientdata(client, data);
456  mutex_init(&data->lock);
457 
458  dev_info(&client->dev, "%s chip found\n", client->name);
459 
460  /* Register sysfs hooks */
461  data->attrs.attrs = ics932s401_attr;
462  err = sysfs_create_group(&client->dev.kobj, &data->attrs);
463  if (err)
464  goto exit_free;
465 
466  return 0;
467 
468 exit_free:
469  kfree(data);
470 exit:
471  return err;
472 }
473 
474 static int ics932s401_remove(struct i2c_client *client)
475 {
476  struct ics932s401_data *data = i2c_get_clientdata(client);
477 
478  sysfs_remove_group(&client->dev.kobj, &data->attrs);
479  kfree(data);
480  return 0;
481 }
482 
483 module_i2c_driver(ics932s401_driver);
484 
485 MODULE_AUTHOR("Darrick J. Wong <[email protected]>");
486 MODULE_DESCRIPTION("ICS932S401 driver");
487 MODULE_LICENSE("GPL");
488 
489 /* IBM IntelliStation Z30 */
490 MODULE_ALIAS("dmi:bvnIBM:*:rn9228:*");
491 MODULE_ALIAS("dmi:bvnIBM:*:rn9232:*");
492 
493 /* IBM x3650/x3550 */
494 MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3650*");
495 MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3550*");
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