xref: /openbmc/linux/drivers/misc/ics932s401.c (revision a09d2831)
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 /* ICS932S401 registers */
34 #define ICS932S401_REG_CFG2			0x01
35 #define 	ICS932S401_CFG1_SPREAD		0x01
36 #define ICS932S401_REG_CFG7			0x06
37 #define		ICS932S401_FS_MASK		0x07
38 #define	ICS932S401_REG_VENDOR_REV		0x07
39 #define		ICS932S401_VENDOR		1
40 #define		ICS932S401_VENDOR_MASK		0x0F
41 #define		ICS932S401_REV			4
42 #define		ICS932S401_REV_SHIFT		4
43 #define ICS932S401_REG_DEVICE			0x09
44 #define		ICS932S401_DEVICE		11
45 #define	ICS932S401_REG_CTRL			0x0A
46 #define		ICS932S401_MN_ENABLED		0x80
47 #define		ICS932S401_CPU_ALT		0x04
48 #define		ICS932S401_SRC_ALT		0x08
49 #define ICS932S401_REG_CPU_M_CTRL		0x0B
50 #define		ICS932S401_M_MASK		0x3F
51 #define	ICS932S401_REG_CPU_N_CTRL		0x0C
52 #define	ICS932S401_REG_CPU_SPREAD1		0x0D
53 #define ICS932S401_REG_CPU_SPREAD2		0x0E
54 #define		ICS932S401_SPREAD_MASK		0x7FFF
55 #define ICS932S401_REG_SRC_M_CTRL		0x0F
56 #define ICS932S401_REG_SRC_N_CTRL		0x10
57 #define	ICS932S401_REG_SRC_SPREAD1		0x11
58 #define ICS932S401_REG_SRC_SPREAD2		0x12
59 #define ICS932S401_REG_CPU_DIVISOR		0x13
60 #define 	ICS932S401_CPU_DIVISOR_SHIFT	4
61 #define ICS932S401_REG_PCISRC_DIVISOR		0x14
62 #define		ICS932S401_SRC_DIVISOR_MASK	0x0F
63 #define		ICS932S401_PCI_DIVISOR_SHIFT	4
64 
65 /* Base clock is 14.318MHz */
66 #define BASE_CLOCK				14318
67 
68 #define NUM_REGS				21
69 #define NUM_MIRRORED_REGS			15
70 
71 static int regs_to_copy[NUM_MIRRORED_REGS] = {
72 	ICS932S401_REG_CFG2,
73 	ICS932S401_REG_CFG7,
74 	ICS932S401_REG_VENDOR_REV,
75 	ICS932S401_REG_DEVICE,
76 	ICS932S401_REG_CTRL,
77 	ICS932S401_REG_CPU_M_CTRL,
78 	ICS932S401_REG_CPU_N_CTRL,
79 	ICS932S401_REG_CPU_SPREAD1,
80 	ICS932S401_REG_CPU_SPREAD2,
81 	ICS932S401_REG_SRC_M_CTRL,
82 	ICS932S401_REG_SRC_N_CTRL,
83 	ICS932S401_REG_SRC_SPREAD1,
84 	ICS932S401_REG_SRC_SPREAD2,
85 	ICS932S401_REG_CPU_DIVISOR,
86 	ICS932S401_REG_PCISRC_DIVISOR,
87 };
88 
89 /* How often do we reread sensors values? (In jiffies) */
90 #define SENSOR_REFRESH_INTERVAL	(2 * HZ)
91 
92 /* How often do we reread sensor limit values? (In jiffies) */
93 #define LIMIT_REFRESH_INTERVAL	(60 * HZ)
94 
95 struct ics932s401_data {
96 	struct attribute_group	attrs;
97 	struct mutex		lock;
98 	char			sensors_valid;
99 	unsigned long		sensors_last_updated;	/* In jiffies */
100 
101 	u8			regs[NUM_REGS];
102 };
103 
104 static int ics932s401_probe(struct i2c_client *client,
105 			 const struct i2c_device_id *id);
106 static int ics932s401_detect(struct i2c_client *client,
107 			  struct i2c_board_info *info);
108 static int ics932s401_remove(struct i2c_client *client);
109 
110 static const struct i2c_device_id ics932s401_id[] = {
111 	{ "ics932s401", 0 },
112 	{ }
113 };
114 MODULE_DEVICE_TABLE(i2c, ics932s401_id);
115 
116 static struct i2c_driver ics932s401_driver = {
117 	.class		= I2C_CLASS_HWMON,
118 	.driver = {
119 		.name	= "ics932s401",
120 	},
121 	.probe		= ics932s401_probe,
122 	.remove		= ics932s401_remove,
123 	.id_table	= ics932s401_id,
124 	.detect		= ics932s401_detect,
125 	.address_list	= normal_i2c,
126 };
127 
128 static struct ics932s401_data *ics932s401_update_device(struct device *dev)
129 {
130 	struct i2c_client *client = to_i2c_client(dev);
131 	struct ics932s401_data *data = i2c_get_clientdata(client);
132 	unsigned long local_jiffies = jiffies;
133 	int i, temp;
134 
135 	mutex_lock(&data->lock);
136 	if (time_before(local_jiffies, data->sensors_last_updated +
137 		SENSOR_REFRESH_INTERVAL)
138 		&& data->sensors_valid)
139 		goto out;
140 
141 	/*
142 	 * Each register must be read as a word and then right shifted 8 bits.
143 	 * Not really sure why this is; setting the "byte count programming"
144 	 * register to 1 does not fix this problem.
145 	 */
146 	for (i = 0; i < NUM_MIRRORED_REGS; i++) {
147 		temp = i2c_smbus_read_word_data(client, regs_to_copy[i]);
148 		data->regs[regs_to_copy[i]] = temp >> 8;
149 	}
150 
151 	data->sensors_last_updated = local_jiffies;
152 	data->sensors_valid = 1;
153 
154 out:
155 	mutex_unlock(&data->lock);
156 	return data;
157 }
158 
159 static ssize_t show_spread_enabled(struct device *dev,
160 				   struct device_attribute *devattr,
161 				   char *buf)
162 {
163 	struct ics932s401_data *data = ics932s401_update_device(dev);
164 
165 	if (data->regs[ICS932S401_REG_CFG2] & ICS932S401_CFG1_SPREAD)
166 		return sprintf(buf, "1\n");
167 
168 	return sprintf(buf, "0\n");
169 }
170 
171 /* bit to cpu khz map */
172 static const int fs_speeds[] = {
173 	266666,
174 	133333,
175 	200000,
176 	166666,
177 	333333,
178 	100000,
179 	400000,
180 	0,
181 };
182 
183 /* clock divisor map */
184 static const int divisors[] = {2, 3, 5, 15, 4, 6, 10, 30, 8, 12, 20, 60, 16,
185 			       24, 40, 120};
186 
187 /* Calculate CPU frequency from the M/N registers. */
188 static int calculate_cpu_freq(struct ics932s401_data *data)
189 {
190 	int m, n, freq;
191 
192 	m = data->regs[ICS932S401_REG_CPU_M_CTRL] & ICS932S401_M_MASK;
193 	n = data->regs[ICS932S401_REG_CPU_N_CTRL];
194 
195 	/* Pull in bits 8 & 9 from the M register */
196 	n |= ((int)data->regs[ICS932S401_REG_CPU_M_CTRL] & 0x80) << 1;
197 	n |= ((int)data->regs[ICS932S401_REG_CPU_M_CTRL] & 0x40) << 3;
198 
199 	freq = BASE_CLOCK * (n + 8) / (m + 2);
200 	freq /= divisors[data->regs[ICS932S401_REG_CPU_DIVISOR] >>
201 			 ICS932S401_CPU_DIVISOR_SHIFT];
202 
203 	return freq;
204 }
205 
206 static ssize_t show_cpu_clock(struct device *dev,
207 			      struct device_attribute *devattr,
208 			      char *buf)
209 {
210 	struct ics932s401_data *data = ics932s401_update_device(dev);
211 
212 	return sprintf(buf, "%d\n", calculate_cpu_freq(data));
213 }
214 
215 static ssize_t show_cpu_clock_sel(struct device *dev,
216 				  struct device_attribute *devattr,
217 				  char *buf)
218 {
219 	struct ics932s401_data *data = ics932s401_update_device(dev);
220 	int freq;
221 
222 	if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
223 		freq = calculate_cpu_freq(data);
224 	else {
225 		/* Freq is neatly wrapped up for us */
226 		int fid = data->regs[ICS932S401_REG_CFG7] & ICS932S401_FS_MASK;
227 		freq = fs_speeds[fid];
228 		if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_CPU_ALT) {
229 			switch (freq) {
230 			case 166666:
231 				freq = 160000;
232 				break;
233 			case 333333:
234 				freq = 320000;
235 				break;
236 			}
237 		}
238 	}
239 
240 	return sprintf(buf, "%d\n", freq);
241 }
242 
243 /* Calculate SRC frequency from the M/N registers. */
244 static int calculate_src_freq(struct ics932s401_data *data)
245 {
246 	int m, n, freq;
247 
248 	m = data->regs[ICS932S401_REG_SRC_M_CTRL] & ICS932S401_M_MASK;
249 	n = data->regs[ICS932S401_REG_SRC_N_CTRL];
250 
251 	/* Pull in bits 8 & 9 from the M register */
252 	n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x80) << 1;
253 	n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x40) << 3;
254 
255 	freq = BASE_CLOCK * (n + 8) / (m + 2);
256 	freq /= divisors[data->regs[ICS932S401_REG_PCISRC_DIVISOR] &
257 			 ICS932S401_SRC_DIVISOR_MASK];
258 
259 	return freq;
260 }
261 
262 static ssize_t show_src_clock(struct device *dev,
263 			      struct device_attribute *devattr,
264 			      char *buf)
265 {
266 	struct ics932s401_data *data = ics932s401_update_device(dev);
267 
268 	return sprintf(buf, "%d\n", calculate_src_freq(data));
269 }
270 
271 static ssize_t show_src_clock_sel(struct device *dev,
272 				  struct device_attribute *devattr,
273 				  char *buf)
274 {
275 	struct ics932s401_data *data = ics932s401_update_device(dev);
276 	int freq;
277 
278 	if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
279 		freq = calculate_src_freq(data);
280 	else
281 		/* Freq is neatly wrapped up for us */
282 		if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_CPU_ALT &&
283 		    data->regs[ICS932S401_REG_CTRL] & ICS932S401_SRC_ALT)
284 			freq = 96000;
285 		else
286 			freq = 100000;
287 
288 	return sprintf(buf, "%d\n", freq);
289 }
290 
291 /* Calculate PCI frequency from the SRC M/N registers. */
292 static int calculate_pci_freq(struct ics932s401_data *data)
293 {
294 	int m, n, freq;
295 
296 	m = data->regs[ICS932S401_REG_SRC_M_CTRL] & ICS932S401_M_MASK;
297 	n = data->regs[ICS932S401_REG_SRC_N_CTRL];
298 
299 	/* Pull in bits 8 & 9 from the M register */
300 	n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x80) << 1;
301 	n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x40) << 3;
302 
303 	freq = BASE_CLOCK * (n + 8) / (m + 2);
304 	freq /= divisors[data->regs[ICS932S401_REG_PCISRC_DIVISOR] >>
305 			 ICS932S401_PCI_DIVISOR_SHIFT];
306 
307 	return freq;
308 }
309 
310 static ssize_t show_pci_clock(struct device *dev,
311 			      struct device_attribute *devattr,
312 			      char *buf)
313 {
314 	struct ics932s401_data *data = ics932s401_update_device(dev);
315 
316 	return sprintf(buf, "%d\n", calculate_pci_freq(data));
317 }
318 
319 static ssize_t show_pci_clock_sel(struct device *dev,
320 				  struct device_attribute *devattr,
321 				  char *buf)
322 {
323 	struct ics932s401_data *data = ics932s401_update_device(dev);
324 	int freq;
325 
326 	if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
327 		freq = calculate_pci_freq(data);
328 	else
329 		freq = 33333;
330 
331 	return sprintf(buf, "%d\n", freq);
332 }
333 
334 static ssize_t show_value(struct device *dev,
335 			  struct device_attribute *devattr,
336 			  char *buf);
337 
338 static ssize_t show_spread(struct device *dev,
339 			   struct device_attribute *devattr,
340 			   char *buf);
341 
342 static DEVICE_ATTR(spread_enabled, S_IRUGO, show_spread_enabled, NULL);
343 static DEVICE_ATTR(cpu_clock_selection, S_IRUGO, show_cpu_clock_sel, NULL);
344 static DEVICE_ATTR(cpu_clock, S_IRUGO, show_cpu_clock, NULL);
345 static DEVICE_ATTR(src_clock_selection, S_IRUGO, show_src_clock_sel, NULL);
346 static DEVICE_ATTR(src_clock, S_IRUGO, show_src_clock, NULL);
347 static DEVICE_ATTR(pci_clock_selection, S_IRUGO, show_pci_clock_sel, NULL);
348 static DEVICE_ATTR(pci_clock, S_IRUGO, show_pci_clock, NULL);
349 static DEVICE_ATTR(usb_clock, S_IRUGO, show_value, NULL);
350 static DEVICE_ATTR(ref_clock, S_IRUGO, show_value, NULL);
351 static DEVICE_ATTR(cpu_spread, S_IRUGO, show_spread, NULL);
352 static DEVICE_ATTR(src_spread, S_IRUGO, show_spread, NULL);
353 
354 static struct attribute *ics932s401_attr[] =
355 {
356 	&dev_attr_spread_enabled.attr,
357 	&dev_attr_cpu_clock_selection.attr,
358 	&dev_attr_cpu_clock.attr,
359 	&dev_attr_src_clock_selection.attr,
360 	&dev_attr_src_clock.attr,
361 	&dev_attr_pci_clock_selection.attr,
362 	&dev_attr_pci_clock.attr,
363 	&dev_attr_usb_clock.attr,
364 	&dev_attr_ref_clock.attr,
365 	&dev_attr_cpu_spread.attr,
366 	&dev_attr_src_spread.attr,
367 	NULL
368 };
369 
370 static ssize_t show_value(struct device *dev,
371 			  struct device_attribute *devattr,
372 			  char *buf)
373 {
374 	int x;
375 
376 	if (devattr == &dev_attr_usb_clock)
377 		x = 48000;
378 	else if (devattr == &dev_attr_ref_clock)
379 		x = BASE_CLOCK;
380 	else
381 		BUG();
382 
383 	return sprintf(buf, "%d\n", x);
384 }
385 
386 static ssize_t show_spread(struct device *dev,
387 			   struct device_attribute *devattr,
388 			   char *buf)
389 {
390 	struct ics932s401_data *data = ics932s401_update_device(dev);
391 	int reg;
392 	unsigned long val;
393 
394 	if (!(data->regs[ICS932S401_REG_CFG2] & ICS932S401_CFG1_SPREAD))
395 		return sprintf(buf, "0%%\n");
396 
397 	if (devattr == &dev_attr_src_spread)
398 		reg = ICS932S401_REG_SRC_SPREAD1;
399 	else if (devattr == &dev_attr_cpu_spread)
400 		reg = ICS932S401_REG_CPU_SPREAD1;
401 	else
402 		BUG();
403 
404 	val = data->regs[reg] | (data->regs[reg + 1] << 8);
405 	val &= ICS932S401_SPREAD_MASK;
406 
407 	/* Scale 0..2^14 to -0.5. */
408 	val = 500000 * val / 16384;
409 	return sprintf(buf, "-0.%lu%%\n", val);
410 }
411 
412 /* Return 0 if detection is successful, -ENODEV otherwise */
413 static int ics932s401_detect(struct i2c_client *client,
414 			  struct i2c_board_info *info)
415 {
416 	struct i2c_adapter *adapter = client->adapter;
417 	int vendor, device, revision;
418 
419 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
420 		return -ENODEV;
421 
422 	vendor = i2c_smbus_read_word_data(client, ICS932S401_REG_VENDOR_REV);
423 	vendor >>= 8;
424 	revision = vendor >> ICS932S401_REV_SHIFT;
425 	vendor &= ICS932S401_VENDOR_MASK;
426 	if (vendor != ICS932S401_VENDOR)
427 		return -ENODEV;
428 
429 	device = i2c_smbus_read_word_data(client, ICS932S401_REG_DEVICE);
430 	device >>= 8;
431 	if (device != ICS932S401_DEVICE)
432 		return -ENODEV;
433 
434 	if (revision != ICS932S401_REV)
435 		dev_info(&adapter->dev, "Unknown revision %d\n", revision);
436 
437 	strlcpy(info->type, "ics932s401", I2C_NAME_SIZE);
438 
439 	return 0;
440 }
441 
442 static int ics932s401_probe(struct i2c_client *client,
443 			 const struct i2c_device_id *id)
444 {
445 	struct ics932s401_data *data;
446 	int err;
447 
448 	data = kzalloc(sizeof(struct ics932s401_data), GFP_KERNEL);
449 	if (!data) {
450 		err = -ENOMEM;
451 		goto exit;
452 	}
453 
454 	i2c_set_clientdata(client, data);
455 	mutex_init(&data->lock);
456 
457 	dev_info(&client->dev, "%s chip found\n", client->name);
458 
459 	/* Register sysfs hooks */
460 	data->attrs.attrs = ics932s401_attr;
461 	err = sysfs_create_group(&client->dev.kobj, &data->attrs);
462 	if (err)
463 		goto exit_free;
464 
465 	return 0;
466 
467 exit_free:
468 	kfree(data);
469 exit:
470 	return err;
471 }
472 
473 static int ics932s401_remove(struct i2c_client *client)
474 {
475 	struct ics932s401_data *data = i2c_get_clientdata(client);
476 
477 	sysfs_remove_group(&client->dev.kobj, &data->attrs);
478 	kfree(data);
479 	return 0;
480 }
481 
482 static int __init ics932s401_init(void)
483 {
484 	return i2c_add_driver(&ics932s401_driver);
485 }
486 
487 static void __exit ics932s401_exit(void)
488 {
489 	i2c_del_driver(&ics932s401_driver);
490 }
491 
492 MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
493 MODULE_DESCRIPTION("ICS932S401 driver");
494 MODULE_LICENSE("GPL");
495 
496 module_init(ics932s401_init);
497 module_exit(ics932s401_exit);
498 
499 /* IBM IntelliStation Z30 */
500 MODULE_ALIAS("dmi:bvnIBM:*:rn9228:*");
501 MODULE_ALIAS("dmi:bvnIBM:*:rn9232:*");
502 
503 /* IBM x3650/x3550 */
504 MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3650*");
505 MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3550*");
506