xref: /openbmc/linux/drivers/misc/ics932s401.c (revision 70342287)
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 #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 <djwong@us.ibm.com>");
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*");
496