xref: /openbmc/linux/drivers/misc/ics932s401.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
1 /*
2  * A driver for the Integrated Circuits ICS932S401
3  * Copyright (C) 2008 IBM
4  *
5  * Author: Darrick J. Wong <djwong@us.ibm.com>
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 
30 /* Addresses to scan */
31 static const unsigned short normal_i2c[] = { 0x69, I2C_CLIENT_END };
32 
33 /* Insmod parameters */
34 I2C_CLIENT_INSMOD_1(ics932s401);
35 
36 /* ICS932S401 registers */
37 #define ICS932S401_REG_CFG2			0x01
38 #define 	ICS932S401_CFG1_SPREAD		0x01
39 #define ICS932S401_REG_CFG7			0x06
40 #define		ICS932S401_FS_MASK		0x07
41 #define	ICS932S401_REG_VENDOR_REV		0x07
42 #define		ICS932S401_VENDOR		1
43 #define		ICS932S401_VENDOR_MASK		0x0F
44 #define		ICS932S401_REV			4
45 #define		ICS932S401_REV_SHIFT		4
46 #define ICS932S401_REG_DEVICE			0x09
47 #define		ICS932S401_DEVICE		11
48 #define	ICS932S401_REG_CTRL			0x0A
49 #define		ICS932S401_MN_ENABLED		0x80
50 #define		ICS932S401_CPU_ALT		0x04
51 #define		ICS932S401_SRC_ALT		0x08
52 #define ICS932S401_REG_CPU_M_CTRL		0x0B
53 #define		ICS932S401_M_MASK		0x3F
54 #define	ICS932S401_REG_CPU_N_CTRL		0x0C
55 #define	ICS932S401_REG_CPU_SPREAD1		0x0D
56 #define ICS932S401_REG_CPU_SPREAD2		0x0E
57 #define		ICS932S401_SPREAD_MASK		0x7FFF
58 #define ICS932S401_REG_SRC_M_CTRL		0x0F
59 #define ICS932S401_REG_SRC_N_CTRL		0x10
60 #define	ICS932S401_REG_SRC_SPREAD1		0x11
61 #define ICS932S401_REG_SRC_SPREAD2		0x12
62 #define ICS932S401_REG_CPU_DIVISOR		0x13
63 #define 	ICS932S401_CPU_DIVISOR_SHIFT	4
64 #define ICS932S401_REG_PCISRC_DIVISOR		0x14
65 #define		ICS932S401_SRC_DIVISOR_MASK	0x0F
66 #define		ICS932S401_PCI_DIVISOR_SHIFT	4
67 
68 /* Base clock is 14.318MHz */
69 #define BASE_CLOCK				14318
70 
71 #define NUM_REGS				21
72 #define NUM_MIRRORED_REGS			15
73 
74 static int regs_to_copy[NUM_MIRRORED_REGS] = {
75 	ICS932S401_REG_CFG2,
76 	ICS932S401_REG_CFG7,
77 	ICS932S401_REG_VENDOR_REV,
78 	ICS932S401_REG_DEVICE,
79 	ICS932S401_REG_CTRL,
80 	ICS932S401_REG_CPU_M_CTRL,
81 	ICS932S401_REG_CPU_N_CTRL,
82 	ICS932S401_REG_CPU_SPREAD1,
83 	ICS932S401_REG_CPU_SPREAD2,
84 	ICS932S401_REG_SRC_M_CTRL,
85 	ICS932S401_REG_SRC_N_CTRL,
86 	ICS932S401_REG_SRC_SPREAD1,
87 	ICS932S401_REG_SRC_SPREAD2,
88 	ICS932S401_REG_CPU_DIVISOR,
89 	ICS932S401_REG_PCISRC_DIVISOR,
90 };
91 
92 /* How often do we reread sensors values? (In jiffies) */
93 #define SENSOR_REFRESH_INTERVAL	(2 * HZ)
94 
95 /* How often do we reread sensor limit values? (In jiffies) */
96 #define LIMIT_REFRESH_INTERVAL	(60 * HZ)
97 
98 struct ics932s401_data {
99 	struct attribute_group	attrs;
100 	struct mutex		lock;
101 	char			sensors_valid;
102 	unsigned long		sensors_last_updated;	/* In jiffies */
103 
104 	u8			regs[NUM_REGS];
105 };
106 
107 static int ics932s401_probe(struct i2c_client *client,
108 			 const struct i2c_device_id *id);
109 static int ics932s401_detect(struct i2c_client *client, int kind,
110 			  struct i2c_board_info *info);
111 static int ics932s401_remove(struct i2c_client *client);
112 
113 static const struct i2c_device_id ics932s401_id[] = {
114 	{ "ics932s401", ics932s401 },
115 	{ }
116 };
117 MODULE_DEVICE_TABLE(i2c, ics932s401_id);
118 
119 static struct i2c_driver ics932s401_driver = {
120 	.class		= I2C_CLASS_HWMON,
121 	.driver = {
122 		.name	= "ics932s401",
123 	},
124 	.probe		= ics932s401_probe,
125 	.remove		= ics932s401_remove,
126 	.id_table	= ics932s401_id,
127 	.detect		= ics932s401_detect,
128 	.address_data	= &addr_data,
129 };
130 
131 static struct ics932s401_data *ics932s401_update_device(struct device *dev)
132 {
133 	struct i2c_client *client = to_i2c_client(dev);
134 	struct ics932s401_data *data = i2c_get_clientdata(client);
135 	unsigned long local_jiffies = jiffies;
136 	int i, temp;
137 
138 	mutex_lock(&data->lock);
139 	if (time_before(local_jiffies, data->sensors_last_updated +
140 		SENSOR_REFRESH_INTERVAL)
141 		&& data->sensors_valid)
142 		goto out;
143 
144 	/*
145 	 * Each register must be read as a word and then right shifted 8 bits.
146 	 * Not really sure why this is; setting the "byte count programming"
147 	 * register to 1 does not fix this problem.
148 	 */
149 	for (i = 0; i < NUM_MIRRORED_REGS; i++) {
150 		temp = i2c_smbus_read_word_data(client, regs_to_copy[i]);
151 		data->regs[regs_to_copy[i]] = temp >> 8;
152 	}
153 
154 	data->sensors_last_updated = local_jiffies;
155 	data->sensors_valid = 1;
156 
157 out:
158 	mutex_unlock(&data->lock);
159 	return data;
160 }
161 
162 static ssize_t show_spread_enabled(struct device *dev,
163 				   struct device_attribute *devattr,
164 				   char *buf)
165 {
166 	struct ics932s401_data *data = ics932s401_update_device(dev);
167 
168 	if (data->regs[ICS932S401_REG_CFG2] & ICS932S401_CFG1_SPREAD)
169 		return sprintf(buf, "1\n");
170 
171 	return sprintf(buf, "0\n");
172 }
173 
174 /* bit to cpu khz map */
175 static const int fs_speeds[] = {
176 	266666,
177 	133333,
178 	200000,
179 	166666,
180 	333333,
181 	100000,
182 	400000,
183 	0,
184 };
185 
186 /* clock divisor map */
187 static const int divisors[] = {2, 3, 5, 15, 4, 6, 10, 30, 8, 12, 20, 60, 16,
188 			       24, 40, 120};
189 
190 /* Calculate CPU frequency from the M/N registers. */
191 static int calculate_cpu_freq(struct ics932s401_data *data)
192 {
193 	int m, n, freq;
194 
195 	m = data->regs[ICS932S401_REG_CPU_M_CTRL] & ICS932S401_M_MASK;
196 	n = data->regs[ICS932S401_REG_CPU_N_CTRL];
197 
198 	/* Pull in bits 8 & 9 from the M register */
199 	n |= ((int)data->regs[ICS932S401_REG_CPU_M_CTRL] & 0x80) << 1;
200 	n |= ((int)data->regs[ICS932S401_REG_CPU_M_CTRL] & 0x40) << 3;
201 
202 	freq = BASE_CLOCK * (n + 8) / (m + 2);
203 	freq /= divisors[data->regs[ICS932S401_REG_CPU_DIVISOR] >>
204 			 ICS932S401_CPU_DIVISOR_SHIFT];
205 
206 	return freq;
207 }
208 
209 static ssize_t show_cpu_clock(struct device *dev,
210 			      struct device_attribute *devattr,
211 			      char *buf)
212 {
213 	struct ics932s401_data *data = ics932s401_update_device(dev);
214 
215 	return sprintf(buf, "%d\n", calculate_cpu_freq(data));
216 }
217 
218 static ssize_t show_cpu_clock_sel(struct device *dev,
219 				  struct device_attribute *devattr,
220 				  char *buf)
221 {
222 	struct ics932s401_data *data = ics932s401_update_device(dev);
223 	int freq;
224 
225 	if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
226 		freq = calculate_cpu_freq(data);
227 	else {
228 		/* Freq is neatly wrapped up for us */
229 		int fid = data->regs[ICS932S401_REG_CFG7] & ICS932S401_FS_MASK;
230 		freq = fs_speeds[fid];
231 		if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_CPU_ALT) {
232 			switch (freq) {
233 			case 166666:
234 				freq = 160000;
235 				break;
236 			case 333333:
237 				freq = 320000;
238 				break;
239 			}
240 		}
241 	}
242 
243 	return sprintf(buf, "%d\n", freq);
244 }
245 
246 /* Calculate SRC frequency from the M/N registers. */
247 static int calculate_src_freq(struct ics932s401_data *data)
248 {
249 	int m, n, freq;
250 
251 	m = data->regs[ICS932S401_REG_SRC_M_CTRL] & ICS932S401_M_MASK;
252 	n = data->regs[ICS932S401_REG_SRC_N_CTRL];
253 
254 	/* Pull in bits 8 & 9 from the M register */
255 	n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x80) << 1;
256 	n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x40) << 3;
257 
258 	freq = BASE_CLOCK * (n + 8) / (m + 2);
259 	freq /= divisors[data->regs[ICS932S401_REG_PCISRC_DIVISOR] &
260 			 ICS932S401_SRC_DIVISOR_MASK];
261 
262 	return freq;
263 }
264 
265 static ssize_t show_src_clock(struct device *dev,
266 			      struct device_attribute *devattr,
267 			      char *buf)
268 {
269 	struct ics932s401_data *data = ics932s401_update_device(dev);
270 
271 	return sprintf(buf, "%d\n", calculate_src_freq(data));
272 }
273 
274 static ssize_t show_src_clock_sel(struct device *dev,
275 				  struct device_attribute *devattr,
276 				  char *buf)
277 {
278 	struct ics932s401_data *data = ics932s401_update_device(dev);
279 	int freq;
280 
281 	if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
282 		freq = calculate_src_freq(data);
283 	else
284 		/* Freq is neatly wrapped up for us */
285 		if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_CPU_ALT &&
286 		    data->regs[ICS932S401_REG_CTRL] & ICS932S401_SRC_ALT)
287 			freq = 96000;
288 		else
289 			freq = 100000;
290 
291 	return sprintf(buf, "%d\n", freq);
292 }
293 
294 /* Calculate PCI frequency from the SRC M/N registers. */
295 static int calculate_pci_freq(struct ics932s401_data *data)
296 {
297 	int m, n, freq;
298 
299 	m = data->regs[ICS932S401_REG_SRC_M_CTRL] & ICS932S401_M_MASK;
300 	n = data->regs[ICS932S401_REG_SRC_N_CTRL];
301 
302 	/* Pull in bits 8 & 9 from the M register */
303 	n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x80) << 1;
304 	n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x40) << 3;
305 
306 	freq = BASE_CLOCK * (n + 8) / (m + 2);
307 	freq /= divisors[data->regs[ICS932S401_REG_PCISRC_DIVISOR] >>
308 			 ICS932S401_PCI_DIVISOR_SHIFT];
309 
310 	return freq;
311 }
312 
313 static ssize_t show_pci_clock(struct device *dev,
314 			      struct device_attribute *devattr,
315 			      char *buf)
316 {
317 	struct ics932s401_data *data = ics932s401_update_device(dev);
318 
319 	return sprintf(buf, "%d\n", calculate_pci_freq(data));
320 }
321 
322 static ssize_t show_pci_clock_sel(struct device *dev,
323 				  struct device_attribute *devattr,
324 				  char *buf)
325 {
326 	struct ics932s401_data *data = ics932s401_update_device(dev);
327 	int freq;
328 
329 	if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
330 		freq = calculate_pci_freq(data);
331 	else
332 		freq = 33333;
333 
334 	return sprintf(buf, "%d\n", freq);
335 }
336 
337 static ssize_t show_value(struct device *dev,
338 			  struct device_attribute *devattr,
339 			  char *buf);
340 
341 static ssize_t show_spread(struct device *dev,
342 			   struct device_attribute *devattr,
343 			   char *buf);
344 
345 static DEVICE_ATTR(spread_enabled, S_IRUGO, show_spread_enabled, NULL);
346 static DEVICE_ATTR(cpu_clock_selection, S_IRUGO, show_cpu_clock_sel, NULL);
347 static DEVICE_ATTR(cpu_clock, S_IRUGO, show_cpu_clock, NULL);
348 static DEVICE_ATTR(src_clock_selection, S_IRUGO, show_src_clock_sel, NULL);
349 static DEVICE_ATTR(src_clock, S_IRUGO, show_src_clock, NULL);
350 static DEVICE_ATTR(pci_clock_selection, S_IRUGO, show_pci_clock_sel, NULL);
351 static DEVICE_ATTR(pci_clock, S_IRUGO, show_pci_clock, NULL);
352 static DEVICE_ATTR(usb_clock, S_IRUGO, show_value, NULL);
353 static DEVICE_ATTR(ref_clock, S_IRUGO, show_value, NULL);
354 static DEVICE_ATTR(cpu_spread, S_IRUGO, show_spread, NULL);
355 static DEVICE_ATTR(src_spread, S_IRUGO, show_spread, NULL);
356 
357 static struct attribute *ics932s401_attr[] =
358 {
359 	&dev_attr_spread_enabled.attr,
360 	&dev_attr_cpu_clock_selection.attr,
361 	&dev_attr_cpu_clock.attr,
362 	&dev_attr_src_clock_selection.attr,
363 	&dev_attr_src_clock.attr,
364 	&dev_attr_pci_clock_selection.attr,
365 	&dev_attr_pci_clock.attr,
366 	&dev_attr_usb_clock.attr,
367 	&dev_attr_ref_clock.attr,
368 	&dev_attr_cpu_spread.attr,
369 	&dev_attr_src_spread.attr,
370 	NULL
371 };
372 
373 static ssize_t show_value(struct device *dev,
374 			  struct device_attribute *devattr,
375 			  char *buf)
376 {
377 	int x;
378 
379 	if (devattr == &dev_attr_usb_clock)
380 		x = 48000;
381 	else if (devattr == &dev_attr_ref_clock)
382 		x = BASE_CLOCK;
383 	else
384 		BUG();
385 
386 	return sprintf(buf, "%d\n", x);
387 }
388 
389 static ssize_t show_spread(struct device *dev,
390 			   struct device_attribute *devattr,
391 			   char *buf)
392 {
393 	struct ics932s401_data *data = ics932s401_update_device(dev);
394 	int reg;
395 	unsigned long val;
396 
397 	if (!(data->regs[ICS932S401_REG_CFG2] & ICS932S401_CFG1_SPREAD))
398 		return sprintf(buf, "0%%\n");
399 
400 	if (devattr == &dev_attr_src_spread)
401 		reg = ICS932S401_REG_SRC_SPREAD1;
402 	else if (devattr == &dev_attr_cpu_spread)
403 		reg = ICS932S401_REG_CPU_SPREAD1;
404 	else
405 		BUG();
406 
407 	val = data->regs[reg] | (data->regs[reg + 1] << 8);
408 	val &= ICS932S401_SPREAD_MASK;
409 
410 	/* Scale 0..2^14 to -0.5. */
411 	val = 500000 * val / 16384;
412 	return sprintf(buf, "-0.%lu%%\n", val);
413 }
414 
415 /* Return 0 if detection is successful, -ENODEV otherwise */
416 static int ics932s401_detect(struct i2c_client *client, int kind,
417 			  struct i2c_board_info *info)
418 {
419 	struct i2c_adapter *adapter = client->adapter;
420 
421 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
422 		return -ENODEV;
423 
424 	if (kind <= 0) {
425 		int vendor, device, revision;
426 
427 		vendor = i2c_smbus_read_word_data(client,
428 						  ICS932S401_REG_VENDOR_REV);
429 		vendor >>= 8;
430 		revision = vendor >> ICS932S401_REV_SHIFT;
431 		vendor &= ICS932S401_VENDOR_MASK;
432 		if (vendor != ICS932S401_VENDOR)
433 			return -ENODEV;
434 
435 		device = i2c_smbus_read_word_data(client,
436 						  ICS932S401_REG_DEVICE);
437 		device >>= 8;
438 		if (device != ICS932S401_DEVICE)
439 			return -ENODEV;
440 
441 		if (revision != ICS932S401_REV)
442 			dev_info(&adapter->dev, "Unknown revision %d\n",
443 				 revision);
444 	} else
445 		dev_dbg(&adapter->dev, "detection forced\n");
446 
447 	strlcpy(info->type, "ics932s401", I2C_NAME_SIZE);
448 
449 	return 0;
450 }
451 
452 static int ics932s401_probe(struct i2c_client *client,
453 			 const struct i2c_device_id *id)
454 {
455 	struct ics932s401_data *data;
456 	int err;
457 
458 	data = kzalloc(sizeof(struct ics932s401_data), GFP_KERNEL);
459 	if (!data) {
460 		err = -ENOMEM;
461 		goto exit;
462 	}
463 
464 	i2c_set_clientdata(client, data);
465 	mutex_init(&data->lock);
466 
467 	dev_info(&client->dev, "%s chip found\n", client->name);
468 
469 	/* Register sysfs hooks */
470 	data->attrs.attrs = ics932s401_attr;
471 	err = sysfs_create_group(&client->dev.kobj, &data->attrs);
472 	if (err)
473 		goto exit_free;
474 
475 	return 0;
476 
477 exit_free:
478 	kfree(data);
479 exit:
480 	return err;
481 }
482 
483 static int ics932s401_remove(struct i2c_client *client)
484 {
485 	struct ics932s401_data *data = i2c_get_clientdata(client);
486 
487 	sysfs_remove_group(&client->dev.kobj, &data->attrs);
488 	kfree(data);
489 	return 0;
490 }
491 
492 static int __init ics932s401_init(void)
493 {
494 	return i2c_add_driver(&ics932s401_driver);
495 }
496 
497 static void __exit ics932s401_exit(void)
498 {
499 	i2c_del_driver(&ics932s401_driver);
500 }
501 
502 MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
503 MODULE_DESCRIPTION("ICS932S401 driver");
504 MODULE_LICENSE("GPL");
505 
506 module_init(ics932s401_init);
507 module_exit(ics932s401_exit);
508 
509 /* IBM IntelliStation Z30 */
510 MODULE_ALIAS("dmi:bvnIBM:*:rn9228:*");
511 MODULE_ALIAS("dmi:bvnIBM:*:rn9232:*");
512 
513 /* IBM x3650/x3550 */
514 MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3650*");
515 MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3550*");
516