xref: /openbmc/linux/drivers/misc/ics932s401.c (revision a531b0c2)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * A driver for the Integrated Circuits ICS932S401
4  * Copyright (C) 2008 IBM
5  *
6  * Author: Darrick J. Wong <darrick.wong@oracle.com>
7  */
8 
9 #include <linux/module.h>
10 #include <linux/jiffies.h>
11 #include <linux/i2c.h>
12 #include <linux/err.h>
13 #include <linux/mutex.h>
14 #include <linux/delay.h>
15 #include <linux/log2.h>
16 #include <linux/slab.h>
17 
18 /* Addresses to scan */
19 static const unsigned short normal_i2c[] = { 0x69, I2C_CLIENT_END };
20 
21 /* ICS932S401 registers */
22 #define ICS932S401_REG_CFG2			0x01
23 #define		ICS932S401_CFG1_SPREAD		0x01
24 #define ICS932S401_REG_CFG7			0x06
25 #define		ICS932S401_FS_MASK		0x07
26 #define	ICS932S401_REG_VENDOR_REV		0x07
27 #define		ICS932S401_VENDOR		1
28 #define		ICS932S401_VENDOR_MASK		0x0F
29 #define		ICS932S401_REV			4
30 #define		ICS932S401_REV_SHIFT		4
31 #define ICS932S401_REG_DEVICE			0x09
32 #define		ICS932S401_DEVICE		11
33 #define	ICS932S401_REG_CTRL			0x0A
34 #define		ICS932S401_MN_ENABLED		0x80
35 #define		ICS932S401_CPU_ALT		0x04
36 #define		ICS932S401_SRC_ALT		0x08
37 #define ICS932S401_REG_CPU_M_CTRL		0x0B
38 #define		ICS932S401_M_MASK		0x3F
39 #define	ICS932S401_REG_CPU_N_CTRL		0x0C
40 #define	ICS932S401_REG_CPU_SPREAD1		0x0D
41 #define ICS932S401_REG_CPU_SPREAD2		0x0E
42 #define		ICS932S401_SPREAD_MASK		0x7FFF
43 #define ICS932S401_REG_SRC_M_CTRL		0x0F
44 #define ICS932S401_REG_SRC_N_CTRL		0x10
45 #define	ICS932S401_REG_SRC_SPREAD1		0x11
46 #define ICS932S401_REG_SRC_SPREAD2		0x12
47 #define ICS932S401_REG_CPU_DIVISOR		0x13
48 #define		ICS932S401_CPU_DIVISOR_SHIFT	4
49 #define ICS932S401_REG_PCISRC_DIVISOR		0x14
50 #define		ICS932S401_SRC_DIVISOR_MASK	0x0F
51 #define		ICS932S401_PCI_DIVISOR_SHIFT	4
52 
53 /* Base clock is 14.318MHz */
54 #define BASE_CLOCK				14318
55 
56 #define NUM_REGS				21
57 #define NUM_MIRRORED_REGS			15
58 
59 static int regs_to_copy[NUM_MIRRORED_REGS] = {
60 	ICS932S401_REG_CFG2,
61 	ICS932S401_REG_CFG7,
62 	ICS932S401_REG_VENDOR_REV,
63 	ICS932S401_REG_DEVICE,
64 	ICS932S401_REG_CTRL,
65 	ICS932S401_REG_CPU_M_CTRL,
66 	ICS932S401_REG_CPU_N_CTRL,
67 	ICS932S401_REG_CPU_SPREAD1,
68 	ICS932S401_REG_CPU_SPREAD2,
69 	ICS932S401_REG_SRC_M_CTRL,
70 	ICS932S401_REG_SRC_N_CTRL,
71 	ICS932S401_REG_SRC_SPREAD1,
72 	ICS932S401_REG_SRC_SPREAD2,
73 	ICS932S401_REG_CPU_DIVISOR,
74 	ICS932S401_REG_PCISRC_DIVISOR,
75 };
76 
77 /* How often do we reread sensors values? (In jiffies) */
78 #define SENSOR_REFRESH_INTERVAL	(2 * HZ)
79 
80 /* How often do we reread sensor limit values? (In jiffies) */
81 #define LIMIT_REFRESH_INTERVAL	(60 * HZ)
82 
83 struct ics932s401_data {
84 	struct attribute_group	attrs;
85 	struct mutex		lock;
86 	char			sensors_valid;
87 	unsigned long		sensors_last_updated;	/* In jiffies */
88 
89 	u8			regs[NUM_REGS];
90 };
91 
92 static int ics932s401_probe(struct i2c_client *client,
93 			 const struct i2c_device_id *id);
94 static int ics932s401_detect(struct i2c_client *client,
95 			  struct i2c_board_info *info);
96 static int ics932s401_remove(struct i2c_client *client);
97 
98 static const struct i2c_device_id ics932s401_id[] = {
99 	{ "ics932s401", 0 },
100 	{ }
101 };
102 MODULE_DEVICE_TABLE(i2c, ics932s401_id);
103 
104 static struct i2c_driver ics932s401_driver = {
105 	.class		= I2C_CLASS_HWMON,
106 	.driver = {
107 		.name	= "ics932s401",
108 	},
109 	.probe		= ics932s401_probe,
110 	.remove		= ics932s401_remove,
111 	.id_table	= ics932s401_id,
112 	.detect		= ics932s401_detect,
113 	.address_list	= normal_i2c,
114 };
115 
116 static struct ics932s401_data *ics932s401_update_device(struct device *dev)
117 {
118 	struct i2c_client *client = to_i2c_client(dev);
119 	struct ics932s401_data *data = i2c_get_clientdata(client);
120 	unsigned long local_jiffies = jiffies;
121 	int i, temp;
122 
123 	mutex_lock(&data->lock);
124 	if (time_before(local_jiffies, data->sensors_last_updated +
125 		SENSOR_REFRESH_INTERVAL)
126 		&& data->sensors_valid)
127 		goto out;
128 
129 	/*
130 	 * Each register must be read as a word and then right shifted 8 bits.
131 	 * Not really sure why this is; setting the "byte count programming"
132 	 * register to 1 does not fix this problem.
133 	 */
134 	for (i = 0; i < NUM_MIRRORED_REGS; i++) {
135 		temp = i2c_smbus_read_word_data(client, regs_to_copy[i]);
136 		if (temp < 0)
137 			temp = 0;
138 		data->regs[regs_to_copy[i]] = temp >> 8;
139 	}
140 
141 	data->sensors_last_updated = local_jiffies;
142 	data->sensors_valid = 1;
143 
144 out:
145 	mutex_unlock(&data->lock);
146 	return data;
147 }
148 
149 static ssize_t show_spread_enabled(struct device *dev,
150 				   struct device_attribute *devattr,
151 				   char *buf)
152 {
153 	struct ics932s401_data *data = ics932s401_update_device(dev);
154 
155 	if (data->regs[ICS932S401_REG_CFG2] & ICS932S401_CFG1_SPREAD)
156 		return sprintf(buf, "1\n");
157 
158 	return sprintf(buf, "0\n");
159 }
160 
161 /* bit to cpu khz map */
162 static const int fs_speeds[] = {
163 	266666,
164 	133333,
165 	200000,
166 	166666,
167 	333333,
168 	100000,
169 	400000,
170 	0,
171 };
172 
173 /* clock divisor map */
174 static const int divisors[] = {2, 3, 5, 15, 4, 6, 10, 30, 8, 12, 20, 60, 16,
175 			       24, 40, 120};
176 
177 /* Calculate CPU frequency from the M/N registers. */
178 static int calculate_cpu_freq(struct ics932s401_data *data)
179 {
180 	int m, n, freq;
181 
182 	m = data->regs[ICS932S401_REG_CPU_M_CTRL] & ICS932S401_M_MASK;
183 	n = data->regs[ICS932S401_REG_CPU_N_CTRL];
184 
185 	/* Pull in bits 8 & 9 from the M register */
186 	n |= ((int)data->regs[ICS932S401_REG_CPU_M_CTRL] & 0x80) << 1;
187 	n |= ((int)data->regs[ICS932S401_REG_CPU_M_CTRL] & 0x40) << 3;
188 
189 	freq = BASE_CLOCK * (n + 8) / (m + 2);
190 	freq /= divisors[data->regs[ICS932S401_REG_CPU_DIVISOR] >>
191 			 ICS932S401_CPU_DIVISOR_SHIFT];
192 
193 	return freq;
194 }
195 
196 static ssize_t show_cpu_clock(struct device *dev,
197 			      struct device_attribute *devattr,
198 			      char *buf)
199 {
200 	struct ics932s401_data *data = ics932s401_update_device(dev);
201 
202 	return sprintf(buf, "%d\n", calculate_cpu_freq(data));
203 }
204 
205 static ssize_t show_cpu_clock_sel(struct device *dev,
206 				  struct device_attribute *devattr,
207 				  char *buf)
208 {
209 	struct ics932s401_data *data = ics932s401_update_device(dev);
210 	int freq;
211 
212 	if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
213 		freq = calculate_cpu_freq(data);
214 	else {
215 		/* Freq is neatly wrapped up for us */
216 		int fid = data->regs[ICS932S401_REG_CFG7] & ICS932S401_FS_MASK;
217 
218 		freq = fs_speeds[fid];
219 		if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_CPU_ALT) {
220 			switch (freq) {
221 			case 166666:
222 				freq = 160000;
223 				break;
224 			case 333333:
225 				freq = 320000;
226 				break;
227 			}
228 		}
229 	}
230 
231 	return sprintf(buf, "%d\n", freq);
232 }
233 
234 /* Calculate SRC frequency from the M/N registers. */
235 static int calculate_src_freq(struct ics932s401_data *data)
236 {
237 	int m, n, freq;
238 
239 	m = data->regs[ICS932S401_REG_SRC_M_CTRL] & ICS932S401_M_MASK;
240 	n = data->regs[ICS932S401_REG_SRC_N_CTRL];
241 
242 	/* Pull in bits 8 & 9 from the M register */
243 	n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x80) << 1;
244 	n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x40) << 3;
245 
246 	freq = BASE_CLOCK * (n + 8) / (m + 2);
247 	freq /= divisors[data->regs[ICS932S401_REG_PCISRC_DIVISOR] &
248 			 ICS932S401_SRC_DIVISOR_MASK];
249 
250 	return freq;
251 }
252 
253 static ssize_t show_src_clock(struct device *dev,
254 			      struct device_attribute *devattr,
255 			      char *buf)
256 {
257 	struct ics932s401_data *data = ics932s401_update_device(dev);
258 
259 	return sprintf(buf, "%d\n", calculate_src_freq(data));
260 }
261 
262 static ssize_t show_src_clock_sel(struct device *dev,
263 				  struct device_attribute *devattr,
264 				  char *buf)
265 {
266 	struct ics932s401_data *data = ics932s401_update_device(dev);
267 	int freq;
268 
269 	if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
270 		freq = calculate_src_freq(data);
271 	else
272 		/* Freq is neatly wrapped up for us */
273 		if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_CPU_ALT &&
274 		    data->regs[ICS932S401_REG_CTRL] & ICS932S401_SRC_ALT)
275 			freq = 96000;
276 		else
277 			freq = 100000;
278 
279 	return sprintf(buf, "%d\n", freq);
280 }
281 
282 /* Calculate PCI frequency from the SRC M/N registers. */
283 static int calculate_pci_freq(struct ics932s401_data *data)
284 {
285 	int m, n, freq;
286 
287 	m = data->regs[ICS932S401_REG_SRC_M_CTRL] & ICS932S401_M_MASK;
288 	n = data->regs[ICS932S401_REG_SRC_N_CTRL];
289 
290 	/* Pull in bits 8 & 9 from the M register */
291 	n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x80) << 1;
292 	n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x40) << 3;
293 
294 	freq = BASE_CLOCK * (n + 8) / (m + 2);
295 	freq /= divisors[data->regs[ICS932S401_REG_PCISRC_DIVISOR] >>
296 			 ICS932S401_PCI_DIVISOR_SHIFT];
297 
298 	return freq;
299 }
300 
301 static ssize_t show_pci_clock(struct device *dev,
302 			      struct device_attribute *devattr,
303 			      char *buf)
304 {
305 	struct ics932s401_data *data = ics932s401_update_device(dev);
306 
307 	return sprintf(buf, "%d\n", calculate_pci_freq(data));
308 }
309 
310 static ssize_t show_pci_clock_sel(struct device *dev,
311 				  struct device_attribute *devattr,
312 				  char *buf)
313 {
314 	struct ics932s401_data *data = ics932s401_update_device(dev);
315 	int freq;
316 
317 	if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
318 		freq = calculate_pci_freq(data);
319 	else
320 		freq = 33333;
321 
322 	return sprintf(buf, "%d\n", freq);
323 }
324 
325 static ssize_t show_value(struct device *dev,
326 			  struct device_attribute *devattr,
327 			  char *buf);
328 
329 static ssize_t show_spread(struct device *dev,
330 			   struct device_attribute *devattr,
331 			   char *buf);
332 
333 static DEVICE_ATTR(spread_enabled, S_IRUGO, show_spread_enabled, NULL);
334 static DEVICE_ATTR(cpu_clock_selection, S_IRUGO, show_cpu_clock_sel, NULL);
335 static DEVICE_ATTR(cpu_clock, S_IRUGO, show_cpu_clock, NULL);
336 static DEVICE_ATTR(src_clock_selection, S_IRUGO, show_src_clock_sel, NULL);
337 static DEVICE_ATTR(src_clock, S_IRUGO, show_src_clock, NULL);
338 static DEVICE_ATTR(pci_clock_selection, S_IRUGO, show_pci_clock_sel, NULL);
339 static DEVICE_ATTR(pci_clock, S_IRUGO, show_pci_clock, NULL);
340 static DEVICE_ATTR(usb_clock, S_IRUGO, show_value, NULL);
341 static DEVICE_ATTR(ref_clock, S_IRUGO, show_value, NULL);
342 static DEVICE_ATTR(cpu_spread, S_IRUGO, show_spread, NULL);
343 static DEVICE_ATTR(src_spread, S_IRUGO, show_spread, NULL);
344 
345 static struct attribute *ics932s401_attr[] = {
346 	&dev_attr_spread_enabled.attr,
347 	&dev_attr_cpu_clock_selection.attr,
348 	&dev_attr_cpu_clock.attr,
349 	&dev_attr_src_clock_selection.attr,
350 	&dev_attr_src_clock.attr,
351 	&dev_attr_pci_clock_selection.attr,
352 	&dev_attr_pci_clock.attr,
353 	&dev_attr_usb_clock.attr,
354 	&dev_attr_ref_clock.attr,
355 	&dev_attr_cpu_spread.attr,
356 	&dev_attr_src_spread.attr,
357 	NULL
358 };
359 
360 static ssize_t show_value(struct device *dev,
361 			  struct device_attribute *devattr,
362 			  char *buf)
363 {
364 	int x;
365 
366 	if (devattr == &dev_attr_usb_clock)
367 		x = 48000;
368 	else if (devattr == &dev_attr_ref_clock)
369 		x = BASE_CLOCK;
370 	else
371 		BUG();
372 
373 	return sprintf(buf, "%d\n", x);
374 }
375 
376 static ssize_t show_spread(struct device *dev,
377 			   struct device_attribute *devattr,
378 			   char *buf)
379 {
380 	struct ics932s401_data *data = ics932s401_update_device(dev);
381 	int reg;
382 	unsigned long val;
383 
384 	if (!(data->regs[ICS932S401_REG_CFG2] & ICS932S401_CFG1_SPREAD))
385 		return sprintf(buf, "0%%\n");
386 
387 	if (devattr == &dev_attr_src_spread)
388 		reg = ICS932S401_REG_SRC_SPREAD1;
389 	else if (devattr == &dev_attr_cpu_spread)
390 		reg = ICS932S401_REG_CPU_SPREAD1;
391 	else
392 		BUG();
393 
394 	val = data->regs[reg] | (data->regs[reg + 1] << 8);
395 	val &= ICS932S401_SPREAD_MASK;
396 
397 	/* Scale 0..2^14 to -0.5. */
398 	val = 500000 * val / 16384;
399 	return sprintf(buf, "-0.%lu%%\n", val);
400 }
401 
402 /* Return 0 if detection is successful, -ENODEV otherwise */
403 static int ics932s401_detect(struct i2c_client *client,
404 			  struct i2c_board_info *info)
405 {
406 	struct i2c_adapter *adapter = client->adapter;
407 	int vendor, device, revision;
408 
409 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
410 		return -ENODEV;
411 
412 	vendor = i2c_smbus_read_word_data(client, ICS932S401_REG_VENDOR_REV);
413 	vendor >>= 8;
414 	revision = vendor >> ICS932S401_REV_SHIFT;
415 	vendor &= ICS932S401_VENDOR_MASK;
416 	if (vendor != ICS932S401_VENDOR)
417 		return -ENODEV;
418 
419 	device = i2c_smbus_read_word_data(client, ICS932S401_REG_DEVICE);
420 	device >>= 8;
421 	if (device != ICS932S401_DEVICE)
422 		return -ENODEV;
423 
424 	if (revision != ICS932S401_REV)
425 		dev_info(&adapter->dev, "Unknown revision %d\n", revision);
426 
427 	strlcpy(info->type, "ics932s401", I2C_NAME_SIZE);
428 
429 	return 0;
430 }
431 
432 static int ics932s401_probe(struct i2c_client *client,
433 			 const struct i2c_device_id *id)
434 {
435 	struct ics932s401_data *data;
436 	int err;
437 
438 	data = kzalloc(sizeof(struct ics932s401_data), GFP_KERNEL);
439 	if (!data) {
440 		err = -ENOMEM;
441 		goto exit;
442 	}
443 
444 	i2c_set_clientdata(client, data);
445 	mutex_init(&data->lock);
446 
447 	dev_info(&client->dev, "%s chip found\n", client->name);
448 
449 	/* Register sysfs hooks */
450 	data->attrs.attrs = ics932s401_attr;
451 	err = sysfs_create_group(&client->dev.kobj, &data->attrs);
452 	if (err)
453 		goto exit_free;
454 
455 	return 0;
456 
457 exit_free:
458 	kfree(data);
459 exit:
460 	return err;
461 }
462 
463 static int ics932s401_remove(struct i2c_client *client)
464 {
465 	struct ics932s401_data *data = i2c_get_clientdata(client);
466 
467 	sysfs_remove_group(&client->dev.kobj, &data->attrs);
468 	kfree(data);
469 	return 0;
470 }
471 
472 module_i2c_driver(ics932s401_driver);
473 
474 MODULE_AUTHOR("Darrick J. Wong <darrick.wong@oracle.com>");
475 MODULE_DESCRIPTION("ICS932S401 driver");
476 MODULE_LICENSE("GPL");
477 
478 /* IBM IntelliStation Z30 */
479 MODULE_ALIAS("dmi:bvnIBM:*:rn9228:*");
480 MODULE_ALIAS("dmi:bvnIBM:*:rn9232:*");
481 
482 /* IBM x3650/x3550 */
483 MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3650*");
484 MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3550*");
485