xref: /openbmc/linux/drivers/hwmon/i5k_amb.c (revision f21e49be)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * A hwmon driver for the Intel 5000 series chipset FB-DIMM AMB
4  * temperature sensors
5  * Copyright (C) 2007 IBM
6  *
7  * Author: Darrick J. Wong <darrick.wong@oracle.com>
8  */
9 
10 #include <linux/module.h>
11 #include <linux/hwmon.h>
12 #include <linux/hwmon-sysfs.h>
13 #include <linux/err.h>
14 #include <linux/mutex.h>
15 #include <linux/log2.h>
16 #include <linux/pci.h>
17 #include <linux/platform_device.h>
18 #include <linux/slab.h>
19 
20 #define DRVNAME "i5k_amb"
21 
22 #define I5K_REG_AMB_BASE_ADDR		0x48
23 #define I5K_REG_AMB_LEN_ADDR		0x50
24 #define I5K_REG_CHAN0_PRESENCE_ADDR	0x64
25 #define I5K_REG_CHAN1_PRESENCE_ADDR	0x66
26 
27 #define AMB_REG_TEMP_MIN_ADDR		0x80
28 #define AMB_REG_TEMP_MID_ADDR		0x81
29 #define AMB_REG_TEMP_MAX_ADDR		0x82
30 #define AMB_REG_TEMP_STATUS_ADDR	0x84
31 #define AMB_REG_TEMP_ADDR		0x85
32 
33 #define AMB_CONFIG_SIZE			2048
34 #define AMB_FUNC_3_OFFSET		768
35 
36 static unsigned long amb_reg_temp_status(unsigned int amb)
37 {
38 	return AMB_FUNC_3_OFFSET + AMB_REG_TEMP_STATUS_ADDR +
39 	       AMB_CONFIG_SIZE * amb;
40 }
41 
42 static unsigned long amb_reg_temp_min(unsigned int amb)
43 {
44 	return AMB_FUNC_3_OFFSET + AMB_REG_TEMP_MIN_ADDR +
45 	       AMB_CONFIG_SIZE * amb;
46 }
47 
48 static unsigned long amb_reg_temp_mid(unsigned int amb)
49 {
50 	return AMB_FUNC_3_OFFSET + AMB_REG_TEMP_MID_ADDR +
51 	       AMB_CONFIG_SIZE * amb;
52 }
53 
54 static unsigned long amb_reg_temp_max(unsigned int amb)
55 {
56 	return AMB_FUNC_3_OFFSET + AMB_REG_TEMP_MAX_ADDR +
57 	       AMB_CONFIG_SIZE * amb;
58 }
59 
60 static unsigned long amb_reg_temp(unsigned int amb)
61 {
62 	return AMB_FUNC_3_OFFSET + AMB_REG_TEMP_ADDR +
63 	       AMB_CONFIG_SIZE * amb;
64 }
65 
66 #define MAX_MEM_CHANNELS		4
67 #define MAX_AMBS_PER_CHANNEL		16
68 #define MAX_AMBS			(MAX_MEM_CHANNELS * \
69 					 MAX_AMBS_PER_CHANNEL)
70 #define CHANNEL_SHIFT			4
71 #define DIMM_MASK			0xF
72 /*
73  * Ugly hack: For some reason the highest bit is set if there
74  * are _any_ DIMMs in the channel.  Attempting to read from
75  * this "high-order" AMB results in a memory bus error, so
76  * for now we'll just ignore that top bit, even though that
77  * might prevent us from seeing the 16th DIMM in the channel.
78  */
79 #define REAL_MAX_AMBS_PER_CHANNEL	15
80 #define KNOBS_PER_AMB			6
81 
82 static unsigned long amb_num_from_reg(unsigned int byte_num, unsigned int bit)
83 {
84 	return byte_num * MAX_AMBS_PER_CHANNEL + bit;
85 }
86 
87 #define AMB_SYSFS_NAME_LEN		16
88 struct i5k_device_attribute {
89 	struct sensor_device_attribute s_attr;
90 	char name[AMB_SYSFS_NAME_LEN];
91 };
92 
93 struct i5k_amb_data {
94 	struct device *hwmon_dev;
95 
96 	unsigned long amb_base;
97 	unsigned long amb_len;
98 	u16 amb_present[MAX_MEM_CHANNELS];
99 	void __iomem *amb_mmio;
100 	struct i5k_device_attribute *attrs;
101 	unsigned int num_attrs;
102 };
103 
104 static ssize_t name_show(struct device *dev, struct device_attribute *devattr,
105 			 char *buf)
106 {
107 	return sprintf(buf, "%s\n", DRVNAME);
108 }
109 
110 
111 static DEVICE_ATTR_RO(name);
112 
113 static struct platform_device *amb_pdev;
114 
115 static u8 amb_read_byte(struct i5k_amb_data *data, unsigned long offset)
116 {
117 	return ioread8(data->amb_mmio + offset);
118 }
119 
120 static void amb_write_byte(struct i5k_amb_data *data, unsigned long offset,
121 			   u8 val)
122 {
123 	iowrite8(val, data->amb_mmio + offset);
124 }
125 
126 static ssize_t show_amb_alarm(struct device *dev,
127 			     struct device_attribute *devattr,
128 			     char *buf)
129 {
130 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
131 	struct i5k_amb_data *data = dev_get_drvdata(dev);
132 
133 	if (!(amb_read_byte(data, amb_reg_temp_status(attr->index)) & 0x20) &&
134 	     (amb_read_byte(data, amb_reg_temp_status(attr->index)) & 0x8))
135 		return sprintf(buf, "1\n");
136 	else
137 		return sprintf(buf, "0\n");
138 }
139 
140 static ssize_t store_amb_min(struct device *dev,
141 			     struct device_attribute *devattr,
142 			     const char *buf,
143 			     size_t count)
144 {
145 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
146 	struct i5k_amb_data *data = dev_get_drvdata(dev);
147 	unsigned long temp;
148 	int ret = kstrtoul(buf, 10, &temp);
149 	if (ret < 0)
150 		return ret;
151 
152 	temp = temp / 500;
153 	if (temp > 255)
154 		temp = 255;
155 
156 	amb_write_byte(data, amb_reg_temp_min(attr->index), temp);
157 	return count;
158 }
159 
160 static ssize_t store_amb_mid(struct device *dev,
161 			     struct device_attribute *devattr,
162 			     const char *buf,
163 			     size_t count)
164 {
165 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
166 	struct i5k_amb_data *data = dev_get_drvdata(dev);
167 	unsigned long temp;
168 	int ret = kstrtoul(buf, 10, &temp);
169 	if (ret < 0)
170 		return ret;
171 
172 	temp = temp / 500;
173 	if (temp > 255)
174 		temp = 255;
175 
176 	amb_write_byte(data, amb_reg_temp_mid(attr->index), temp);
177 	return count;
178 }
179 
180 static ssize_t store_amb_max(struct device *dev,
181 			     struct device_attribute *devattr,
182 			     const char *buf,
183 			     size_t count)
184 {
185 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
186 	struct i5k_amb_data *data = dev_get_drvdata(dev);
187 	unsigned long temp;
188 	int ret = kstrtoul(buf, 10, &temp);
189 	if (ret < 0)
190 		return ret;
191 
192 	temp = temp / 500;
193 	if (temp > 255)
194 		temp = 255;
195 
196 	amb_write_byte(data, amb_reg_temp_max(attr->index), temp);
197 	return count;
198 }
199 
200 static ssize_t show_amb_min(struct device *dev,
201 			     struct device_attribute *devattr,
202 			     char *buf)
203 {
204 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
205 	struct i5k_amb_data *data = dev_get_drvdata(dev);
206 	return sprintf(buf, "%d\n",
207 		500 * amb_read_byte(data, amb_reg_temp_min(attr->index)));
208 }
209 
210 static ssize_t show_amb_mid(struct device *dev,
211 			     struct device_attribute *devattr,
212 			     char *buf)
213 {
214 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
215 	struct i5k_amb_data *data = dev_get_drvdata(dev);
216 	return sprintf(buf, "%d\n",
217 		500 * amb_read_byte(data, amb_reg_temp_mid(attr->index)));
218 }
219 
220 static ssize_t show_amb_max(struct device *dev,
221 			     struct device_attribute *devattr,
222 			     char *buf)
223 {
224 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
225 	struct i5k_amb_data *data = dev_get_drvdata(dev);
226 	return sprintf(buf, "%d\n",
227 		500 * amb_read_byte(data, amb_reg_temp_max(attr->index)));
228 }
229 
230 static ssize_t show_amb_temp(struct device *dev,
231 			     struct device_attribute *devattr,
232 			     char *buf)
233 {
234 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
235 	struct i5k_amb_data *data = dev_get_drvdata(dev);
236 	return sprintf(buf, "%d\n",
237 		500 * amb_read_byte(data, amb_reg_temp(attr->index)));
238 }
239 
240 static ssize_t show_label(struct device *dev,
241 			  struct device_attribute *devattr,
242 			  char *buf)
243 {
244 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
245 
246 	return sprintf(buf, "Ch. %d DIMM %d\n", attr->index >> CHANNEL_SHIFT,
247 		       attr->index & DIMM_MASK);
248 }
249 
250 static int i5k_amb_hwmon_init(struct platform_device *pdev)
251 {
252 	int i, j, k, d = 0;
253 	u16 c;
254 	int res = 0;
255 	int num_ambs = 0;
256 	struct i5k_amb_data *data = platform_get_drvdata(pdev);
257 
258 	/* Count the number of AMBs found */
259 	/* ignore the high-order bit, see "Ugly hack" comment above */
260 	for (i = 0; i < MAX_MEM_CHANNELS; i++)
261 		num_ambs += hweight16(data->amb_present[i] & 0x7fff);
262 
263 	/* Set up sysfs stuff */
264 	data->attrs = kzalloc(array3_size(num_ambs, KNOBS_PER_AMB,
265 					  sizeof(*data->attrs)),
266 			      GFP_KERNEL);
267 	if (!data->attrs)
268 		return -ENOMEM;
269 	data->num_attrs = 0;
270 
271 	for (i = 0; i < MAX_MEM_CHANNELS; i++) {
272 		c = data->amb_present[i];
273 		for (j = 0; j < REAL_MAX_AMBS_PER_CHANNEL; j++, c >>= 1) {
274 			struct i5k_device_attribute *iattr;
275 
276 			k = amb_num_from_reg(i, j);
277 			if (!(c & 0x1))
278 				continue;
279 			d++;
280 
281 			/* sysfs label */
282 			iattr = data->attrs + data->num_attrs;
283 			snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
284 				 "temp%d_label", d);
285 			iattr->s_attr.dev_attr.attr.name = iattr->name;
286 			iattr->s_attr.dev_attr.attr.mode = 0444;
287 			iattr->s_attr.dev_attr.show = show_label;
288 			iattr->s_attr.index = k;
289 			sysfs_attr_init(&iattr->s_attr.dev_attr.attr);
290 			res = device_create_file(&pdev->dev,
291 						 &iattr->s_attr.dev_attr);
292 			if (res)
293 				goto exit_remove;
294 			data->num_attrs++;
295 
296 			/* Temperature sysfs knob */
297 			iattr = data->attrs + data->num_attrs;
298 			snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
299 				 "temp%d_input", d);
300 			iattr->s_attr.dev_attr.attr.name = iattr->name;
301 			iattr->s_attr.dev_attr.attr.mode = 0444;
302 			iattr->s_attr.dev_attr.show = show_amb_temp;
303 			iattr->s_attr.index = k;
304 			sysfs_attr_init(&iattr->s_attr.dev_attr.attr);
305 			res = device_create_file(&pdev->dev,
306 						 &iattr->s_attr.dev_attr);
307 			if (res)
308 				goto exit_remove;
309 			data->num_attrs++;
310 
311 			/* Temperature min sysfs knob */
312 			iattr = data->attrs + data->num_attrs;
313 			snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
314 				 "temp%d_min", d);
315 			iattr->s_attr.dev_attr.attr.name = iattr->name;
316 			iattr->s_attr.dev_attr.attr.mode = 0644;
317 			iattr->s_attr.dev_attr.show = show_amb_min;
318 			iattr->s_attr.dev_attr.store = store_amb_min;
319 			iattr->s_attr.index = k;
320 			sysfs_attr_init(&iattr->s_attr.dev_attr.attr);
321 			res = device_create_file(&pdev->dev,
322 						 &iattr->s_attr.dev_attr);
323 			if (res)
324 				goto exit_remove;
325 			data->num_attrs++;
326 
327 			/* Temperature mid sysfs knob */
328 			iattr = data->attrs + data->num_attrs;
329 			snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
330 				 "temp%d_mid", d);
331 			iattr->s_attr.dev_attr.attr.name = iattr->name;
332 			iattr->s_attr.dev_attr.attr.mode = 0644;
333 			iattr->s_attr.dev_attr.show = show_amb_mid;
334 			iattr->s_attr.dev_attr.store = store_amb_mid;
335 			iattr->s_attr.index = k;
336 			sysfs_attr_init(&iattr->s_attr.dev_attr.attr);
337 			res = device_create_file(&pdev->dev,
338 						 &iattr->s_attr.dev_attr);
339 			if (res)
340 				goto exit_remove;
341 			data->num_attrs++;
342 
343 			/* Temperature max sysfs knob */
344 			iattr = data->attrs + data->num_attrs;
345 			snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
346 				 "temp%d_max", d);
347 			iattr->s_attr.dev_attr.attr.name = iattr->name;
348 			iattr->s_attr.dev_attr.attr.mode = 0644;
349 			iattr->s_attr.dev_attr.show = show_amb_max;
350 			iattr->s_attr.dev_attr.store = store_amb_max;
351 			iattr->s_attr.index = k;
352 			sysfs_attr_init(&iattr->s_attr.dev_attr.attr);
353 			res = device_create_file(&pdev->dev,
354 						 &iattr->s_attr.dev_attr);
355 			if (res)
356 				goto exit_remove;
357 			data->num_attrs++;
358 
359 			/* Temperature alarm sysfs knob */
360 			iattr = data->attrs + data->num_attrs;
361 			snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
362 				 "temp%d_alarm", d);
363 			iattr->s_attr.dev_attr.attr.name = iattr->name;
364 			iattr->s_attr.dev_attr.attr.mode = 0444;
365 			iattr->s_attr.dev_attr.show = show_amb_alarm;
366 			iattr->s_attr.index = k;
367 			sysfs_attr_init(&iattr->s_attr.dev_attr.attr);
368 			res = device_create_file(&pdev->dev,
369 						 &iattr->s_attr.dev_attr);
370 			if (res)
371 				goto exit_remove;
372 			data->num_attrs++;
373 		}
374 	}
375 
376 	res = device_create_file(&pdev->dev, &dev_attr_name);
377 	if (res)
378 		goto exit_remove;
379 
380 	data->hwmon_dev = hwmon_device_register(&pdev->dev);
381 	if (IS_ERR(data->hwmon_dev)) {
382 		res = PTR_ERR(data->hwmon_dev);
383 		goto exit_remove;
384 	}
385 
386 	return res;
387 
388 exit_remove:
389 	device_remove_file(&pdev->dev, &dev_attr_name);
390 	for (i = 0; i < data->num_attrs; i++)
391 		device_remove_file(&pdev->dev, &data->attrs[i].s_attr.dev_attr);
392 	kfree(data->attrs);
393 
394 	return res;
395 }
396 
397 static int i5k_amb_add(void)
398 {
399 	int res;
400 
401 	/* only ever going to be one of these */
402 	amb_pdev = platform_device_alloc(DRVNAME, 0);
403 	if (!amb_pdev)
404 		return -ENOMEM;
405 
406 	res = platform_device_add(amb_pdev);
407 	if (res)
408 		goto err;
409 	return 0;
410 
411 err:
412 	platform_device_put(amb_pdev);
413 	return res;
414 }
415 
416 static int i5k_find_amb_registers(struct i5k_amb_data *data,
417 					    unsigned long devid)
418 {
419 	struct pci_dev *pcidev;
420 	u32 val32;
421 	int res = -ENODEV;
422 
423 	/* Find AMB register memory space */
424 	pcidev = pci_get_device(PCI_VENDOR_ID_INTEL,
425 				devid,
426 				NULL);
427 	if (!pcidev)
428 		return -ENODEV;
429 
430 	pci_read_config_dword(pcidev, I5K_REG_AMB_BASE_ADDR, &val32);
431 	if (val32 == (u32)~0)
432 		goto out;
433 	data->amb_base = val32;
434 
435 	pci_read_config_dword(pcidev, I5K_REG_AMB_LEN_ADDR, &val32);
436 	if (val32 == (u32)~0)
437 		goto out;
438 	data->amb_len = val32;
439 
440 	/* Is it big enough? */
441 	if (data->amb_len < AMB_CONFIG_SIZE * MAX_AMBS) {
442 		dev_err(&pcidev->dev, "AMB region too small!\n");
443 		goto out;
444 	}
445 
446 	res = 0;
447 out:
448 	pci_dev_put(pcidev);
449 	return res;
450 }
451 
452 static int i5k_channel_probe(u16 *amb_present, unsigned long dev_id)
453 {
454 	struct pci_dev *pcidev;
455 	u16 val16;
456 	int res = -ENODEV;
457 
458 	/* Copy the DIMM presence map for these two channels */
459 	pcidev = pci_get_device(PCI_VENDOR_ID_INTEL, dev_id, NULL);
460 	if (!pcidev)
461 		return -ENODEV;
462 
463 	pci_read_config_word(pcidev, I5K_REG_CHAN0_PRESENCE_ADDR, &val16);
464 	if (val16 == (u16)~0)
465 		goto out;
466 	amb_present[0] = val16;
467 
468 	pci_read_config_word(pcidev, I5K_REG_CHAN1_PRESENCE_ADDR, &val16);
469 	if (val16 == (u16)~0)
470 		goto out;
471 	amb_present[1] = val16;
472 
473 	res = 0;
474 
475 out:
476 	pci_dev_put(pcidev);
477 	return res;
478 }
479 
480 static struct {
481 	unsigned long err;
482 	unsigned long fbd0;
483 } chipset_ids[]  = {
484 	{ PCI_DEVICE_ID_INTEL_5000_ERR, PCI_DEVICE_ID_INTEL_5000_FBD0 },
485 	{ PCI_DEVICE_ID_INTEL_5400_ERR, PCI_DEVICE_ID_INTEL_5400_FBD0 },
486 	{ 0, 0 }
487 };
488 
489 #ifdef MODULE
490 static const struct pci_device_id i5k_amb_ids[] = {
491 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_5000_ERR) },
492 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_5400_ERR) },
493 	{ 0, }
494 };
495 MODULE_DEVICE_TABLE(pci, i5k_amb_ids);
496 #endif
497 
498 static int i5k_amb_probe(struct platform_device *pdev)
499 {
500 	struct i5k_amb_data *data;
501 	struct resource *reso;
502 	int i, res;
503 
504 	data = kzalloc(sizeof(*data), GFP_KERNEL);
505 	if (!data)
506 		return -ENOMEM;
507 
508 	/* Figure out where the AMB registers live */
509 	i = 0;
510 	do {
511 		res = i5k_find_amb_registers(data, chipset_ids[i].err);
512 		if (res == 0)
513 			break;
514 		i++;
515 	} while (chipset_ids[i].err);
516 
517 	if (res)
518 		goto err;
519 
520 	/* Copy the DIMM presence map for the first two channels */
521 	res = i5k_channel_probe(&data->amb_present[0], chipset_ids[i].fbd0);
522 	if (res)
523 		goto err;
524 
525 	/* Copy the DIMM presence map for the optional second two channels */
526 	i5k_channel_probe(&data->amb_present[2], chipset_ids[i].fbd0 + 1);
527 
528 	/* Set up resource regions */
529 	reso = request_mem_region(data->amb_base, data->amb_len, DRVNAME);
530 	if (!reso) {
531 		res = -EBUSY;
532 		goto err;
533 	}
534 
535 	data->amb_mmio = ioremap(data->amb_base, data->amb_len);
536 	if (!data->amb_mmio) {
537 		res = -EBUSY;
538 		goto err_map_failed;
539 	}
540 
541 	platform_set_drvdata(pdev, data);
542 
543 	res = i5k_amb_hwmon_init(pdev);
544 	if (res)
545 		goto err_init_failed;
546 
547 	return res;
548 
549 err_init_failed:
550 	iounmap(data->amb_mmio);
551 err_map_failed:
552 	release_mem_region(data->amb_base, data->amb_len);
553 err:
554 	kfree(data);
555 	return res;
556 }
557 
558 static int i5k_amb_remove(struct platform_device *pdev)
559 {
560 	int i;
561 	struct i5k_amb_data *data = platform_get_drvdata(pdev);
562 
563 	hwmon_device_unregister(data->hwmon_dev);
564 	device_remove_file(&pdev->dev, &dev_attr_name);
565 	for (i = 0; i < data->num_attrs; i++)
566 		device_remove_file(&pdev->dev, &data->attrs[i].s_attr.dev_attr);
567 	kfree(data->attrs);
568 	iounmap(data->amb_mmio);
569 	release_mem_region(data->amb_base, data->amb_len);
570 	kfree(data);
571 	return 0;
572 }
573 
574 static struct platform_driver i5k_amb_driver = {
575 	.driver = {
576 		.name = DRVNAME,
577 	},
578 	.probe = i5k_amb_probe,
579 	.remove = i5k_amb_remove,
580 };
581 
582 static int __init i5k_amb_init(void)
583 {
584 	int res;
585 
586 	res = platform_driver_register(&i5k_amb_driver);
587 	if (res)
588 		return res;
589 
590 	res = i5k_amb_add();
591 	if (res)
592 		platform_driver_unregister(&i5k_amb_driver);
593 
594 	return res;
595 }
596 
597 static void __exit i5k_amb_exit(void)
598 {
599 	platform_device_unregister(amb_pdev);
600 	platform_driver_unregister(&i5k_amb_driver);
601 }
602 
603 MODULE_AUTHOR("Darrick J. Wong <darrick.wong@oracle.com>");
604 MODULE_DESCRIPTION("Intel 5000 chipset FB-DIMM AMB temperature sensor");
605 MODULE_LICENSE("GPL");
606 
607 module_init(i5k_amb_init);
608 module_exit(i5k_amb_exit);
609