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
36static 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
42static 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
48static 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
54static 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
60static 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
82static 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
88struct i5k_device_attribute {
89	struct sensor_device_attribute s_attr;
90	char name[AMB_SYSFS_NAME_LEN];
91};
92
93struct 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
104static 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
111static DEVICE_ATTR_RO(name);
112
113static struct platform_device *amb_pdev;
114
115static u8 amb_read_byte(struct i5k_amb_data *data, unsigned long offset)
116{
117	return ioread8(data->amb_mmio + offset);
118}
119
120static 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
126static 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
140static 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
160static 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
180static 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
200static 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
210static 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
220static 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
230static 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
240static 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
250static 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
388exit_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
397static 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
411err:
412	platform_device_put(amb_pdev);
413	return res;
414}
415
416static 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;
447out:
448	pci_dev_put(pcidev);
449	return res;
450}
451
452static 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
475out:
476	pci_dev_put(pcidev);
477	return res;
478}
479
480static 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
490static 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};
495MODULE_DEVICE_TABLE(pci, i5k_amb_ids);
496#endif
497
498static 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
549err_init_failed:
550	iounmap(data->amb_mmio);
551err_map_failed:
552	release_mem_region(data->amb_base, data->amb_len);
553err:
554	kfree(data);
555	return res;
556}
557
558static void 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}
572
573static struct platform_driver i5k_amb_driver = {
574	.driver = {
575		.name = DRVNAME,
576	},
577	.probe = i5k_amb_probe,
578	.remove_new = i5k_amb_remove,
579};
580
581static int __init i5k_amb_init(void)
582{
583	int res;
584
585	res = platform_driver_register(&i5k_amb_driver);
586	if (res)
587		return res;
588
589	res = i5k_amb_add();
590	if (res)
591		platform_driver_unregister(&i5k_amb_driver);
592
593	return res;
594}
595
596static void __exit i5k_amb_exit(void)
597{
598	platform_device_unregister(amb_pdev);
599	platform_driver_unregister(&i5k_amb_driver);
600}
601
602MODULE_AUTHOR("Darrick J. Wong <darrick.wong@oracle.com>");
603MODULE_DESCRIPTION("Intel 5000 chipset FB-DIMM AMB temperature sensor");
604MODULE_LICENSE("GPL");
605
606module_init(i5k_amb_init);
607module_exit(i5k_amb_exit);
608