xref: /openbmc/linux/drivers/hwmon/i5k_amb.c (revision f42b3800)
1 /*
2  * A hwmon driver for the Intel 5000 series chipset FB-DIMM AMB
3  * temperature sensors
4  * Copyright (C) 2007 IBM
5  *
6  * Author: Darrick J. Wong <djwong@us.ibm.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
21  */
22 
23 #include <linux/module.h>
24 #include <linux/jiffies.h>
25 #include <linux/hwmon.h>
26 #include <linux/hwmon-sysfs.h>
27 #include <linux/err.h>
28 #include <linux/mutex.h>
29 #include <linux/delay.h>
30 #include <linux/log2.h>
31 #include <linux/pci.h>
32 #include <linux/platform_device.h>
33 
34 #define DRVNAME "i5k_amb"
35 
36 #define I5K_REG_AMB_BASE_ADDR		0x48
37 #define I5K_REG_AMB_LEN_ADDR		0x50
38 #define I5K_REG_CHAN0_PRESENCE_ADDR	0x64
39 #define I5K_REG_CHAN1_PRESENCE_ADDR	0x66
40 
41 #define AMB_REG_TEMP_MIN_ADDR		0x80
42 #define AMB_REG_TEMP_MID_ADDR		0x81
43 #define AMB_REG_TEMP_MAX_ADDR		0x82
44 #define AMB_REG_TEMP_STATUS_ADDR	0x84
45 #define AMB_REG_TEMP_ADDR		0x85
46 
47 #define AMB_CONFIG_SIZE			2048
48 #define AMB_FUNC_3_OFFSET		768
49 
50 static unsigned long amb_reg_temp_status(unsigned int amb)
51 {
52 	return AMB_FUNC_3_OFFSET + AMB_REG_TEMP_STATUS_ADDR +
53 	       AMB_CONFIG_SIZE * amb;
54 }
55 
56 static unsigned long amb_reg_temp_min(unsigned int amb)
57 {
58 	return AMB_FUNC_3_OFFSET + AMB_REG_TEMP_MIN_ADDR +
59 	       AMB_CONFIG_SIZE * amb;
60 }
61 
62 static unsigned long amb_reg_temp_mid(unsigned int amb)
63 {
64 	return AMB_FUNC_3_OFFSET + AMB_REG_TEMP_MID_ADDR +
65 	       AMB_CONFIG_SIZE * amb;
66 }
67 
68 static unsigned long amb_reg_temp_max(unsigned int amb)
69 {
70 	return AMB_FUNC_3_OFFSET + AMB_REG_TEMP_MAX_ADDR +
71 	       AMB_CONFIG_SIZE * amb;
72 }
73 
74 static unsigned long amb_reg_temp(unsigned int amb)
75 {
76 	return AMB_FUNC_3_OFFSET + AMB_REG_TEMP_ADDR +
77 	       AMB_CONFIG_SIZE * amb;
78 }
79 
80 #define MAX_MEM_CHANNELS		4
81 #define MAX_AMBS_PER_CHANNEL		16
82 #define MAX_AMBS			(MAX_MEM_CHANNELS * \
83 					 MAX_AMBS_PER_CHANNEL)
84 /*
85  * Ugly hack: For some reason the highest bit is set if there
86  * are _any_ DIMMs in the channel.  Attempting to read from
87  * this "high-order" AMB results in a memory bus error, so
88  * for now we'll just ignore that top bit, even though that
89  * might prevent us from seeing the 16th DIMM in the channel.
90  */
91 #define REAL_MAX_AMBS_PER_CHANNEL	15
92 #define KNOBS_PER_AMB			5
93 
94 static unsigned long amb_num_from_reg(unsigned int byte_num, unsigned int bit)
95 {
96 	return byte_num * MAX_AMBS_PER_CHANNEL + bit;
97 }
98 
99 #define AMB_SYSFS_NAME_LEN		16
100 struct i5k_device_attribute {
101 	struct sensor_device_attribute s_attr;
102 	char name[AMB_SYSFS_NAME_LEN];
103 };
104 
105 struct i5k_amb_data {
106 	struct device *hwmon_dev;
107 
108 	unsigned long amb_base;
109 	unsigned long amb_len;
110 	u16 amb_present[MAX_MEM_CHANNELS];
111 	void __iomem *amb_mmio;
112 	struct i5k_device_attribute *attrs;
113 	unsigned int num_attrs;
114 };
115 
116 static ssize_t show_name(struct device *dev, struct device_attribute *devattr,
117 			 char *buf)
118 {
119 	return sprintf(buf, "%s\n", DRVNAME);
120 }
121 
122 
123 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
124 
125 static struct platform_device *amb_pdev;
126 
127 static u8 amb_read_byte(struct i5k_amb_data *data, unsigned long offset)
128 {
129 	return ioread8(data->amb_mmio + offset);
130 }
131 
132 static void amb_write_byte(struct i5k_amb_data *data, unsigned long offset,
133 			   u8 val)
134 {
135 	iowrite8(val, data->amb_mmio + offset);
136 }
137 
138 static ssize_t show_amb_alarm(struct device *dev,
139 			     struct device_attribute *devattr,
140 			     char *buf)
141 {
142 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
143 	struct i5k_amb_data *data = dev_get_drvdata(dev);
144 
145 	if (!(amb_read_byte(data, amb_reg_temp_status(attr->index)) & 0x20) &&
146 	     (amb_read_byte(data, amb_reg_temp_status(attr->index)) & 0x8))
147 		return sprintf(buf, "1\n");
148 	else
149 		return sprintf(buf, "0\n");
150 }
151 
152 static ssize_t store_amb_min(struct device *dev,
153 			     struct device_attribute *devattr,
154 			     const char *buf,
155 			     size_t count)
156 {
157 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
158 	struct i5k_amb_data *data = dev_get_drvdata(dev);
159 	unsigned long temp = simple_strtoul(buf, NULL, 10) / 500;
160 
161 	if (temp > 255)
162 		temp = 255;
163 
164 	amb_write_byte(data, amb_reg_temp_min(attr->index), temp);
165 	return count;
166 }
167 
168 static ssize_t store_amb_mid(struct device *dev,
169 			     struct device_attribute *devattr,
170 			     const char *buf,
171 			     size_t count)
172 {
173 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
174 	struct i5k_amb_data *data = dev_get_drvdata(dev);
175 	unsigned long temp = simple_strtoul(buf, NULL, 10) / 500;
176 
177 	if (temp > 255)
178 		temp = 255;
179 
180 	amb_write_byte(data, amb_reg_temp_mid(attr->index), temp);
181 	return count;
182 }
183 
184 static ssize_t store_amb_max(struct device *dev,
185 			     struct device_attribute *devattr,
186 			     const char *buf,
187 			     size_t count)
188 {
189 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
190 	struct i5k_amb_data *data = dev_get_drvdata(dev);
191 	unsigned long temp = simple_strtoul(buf, NULL, 10) / 500;
192 
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 int __devinit i5k_amb_hwmon_init(struct platform_device *pdev)
241 {
242 	int i, j, k, d = 0;
243 	u16 c;
244 	int res = 0;
245 	int num_ambs = 0;
246 	struct i5k_amb_data *data = platform_get_drvdata(pdev);
247 
248 	/* Count the number of AMBs found */
249 	/* ignore the high-order bit, see "Ugly hack" comment above */
250 	for (i = 0; i < MAX_MEM_CHANNELS; i++)
251 		num_ambs += hweight16(data->amb_present[i] & 0x7fff);
252 
253 	/* Set up sysfs stuff */
254 	data->attrs = kzalloc(sizeof(*data->attrs) * num_ambs * KNOBS_PER_AMB,
255 				GFP_KERNEL);
256 	if (!data->attrs)
257 		return -ENOMEM;
258 	data->num_attrs = 0;
259 
260 	for (i = 0; i < MAX_MEM_CHANNELS; i++) {
261 		c = data->amb_present[i];
262 		for (j = 0; j < REAL_MAX_AMBS_PER_CHANNEL; j++, c >>= 1) {
263 			struct i5k_device_attribute *iattr;
264 
265 			k = amb_num_from_reg(i, j);
266 			if (!(c & 0x1))
267 				continue;
268 			d++;
269 
270 			/* Temperature sysfs knob */
271 			iattr = data->attrs + data->num_attrs;
272 			snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
273 				 "temp%d_input", d);
274 			iattr->s_attr.dev_attr.attr.name = iattr->name;
275 			iattr->s_attr.dev_attr.attr.mode = S_IRUGO;
276 			iattr->s_attr.dev_attr.show = show_amb_temp;
277 			iattr->s_attr.index = k;
278 			res = device_create_file(&pdev->dev,
279 						 &iattr->s_attr.dev_attr);
280 			if (res)
281 				goto exit_remove;
282 			data->num_attrs++;
283 
284 			/* Temperature min sysfs knob */
285 			iattr = data->attrs + data->num_attrs;
286 			snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
287 				 "temp%d_min", d);
288 			iattr->s_attr.dev_attr.attr.name = iattr->name;
289 			iattr->s_attr.dev_attr.attr.mode = S_IWUSR | S_IRUGO;
290 			iattr->s_attr.dev_attr.show = show_amb_min;
291 			iattr->s_attr.dev_attr.store = store_amb_min;
292 			iattr->s_attr.index = k;
293 			res = device_create_file(&pdev->dev,
294 						 &iattr->s_attr.dev_attr);
295 			if (res)
296 				goto exit_remove;
297 			data->num_attrs++;
298 
299 			/* Temperature mid sysfs knob */
300 			iattr = data->attrs + data->num_attrs;
301 			snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
302 				 "temp%d_mid", d);
303 			iattr->s_attr.dev_attr.attr.name = iattr->name;
304 			iattr->s_attr.dev_attr.attr.mode = S_IWUSR | S_IRUGO;
305 			iattr->s_attr.dev_attr.show = show_amb_mid;
306 			iattr->s_attr.dev_attr.store = store_amb_mid;
307 			iattr->s_attr.index = k;
308 			res = device_create_file(&pdev->dev,
309 						 &iattr->s_attr.dev_attr);
310 			if (res)
311 				goto exit_remove;
312 			data->num_attrs++;
313 
314 			/* Temperature max sysfs knob */
315 			iattr = data->attrs + data->num_attrs;
316 			snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
317 				 "temp%d_max", d);
318 			iattr->s_attr.dev_attr.attr.name = iattr->name;
319 			iattr->s_attr.dev_attr.attr.mode = S_IWUSR | S_IRUGO;
320 			iattr->s_attr.dev_attr.show = show_amb_max;
321 			iattr->s_attr.dev_attr.store = store_amb_max;
322 			iattr->s_attr.index = k;
323 			res = device_create_file(&pdev->dev,
324 						 &iattr->s_attr.dev_attr);
325 			if (res)
326 				goto exit_remove;
327 			data->num_attrs++;
328 
329 			/* Temperature alarm sysfs knob */
330 			iattr = data->attrs + data->num_attrs;
331 			snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
332 				 "temp%d_alarm", d);
333 			iattr->s_attr.dev_attr.attr.name = iattr->name;
334 			iattr->s_attr.dev_attr.attr.mode = S_IRUGO;
335 			iattr->s_attr.dev_attr.show = show_amb_alarm;
336 			iattr->s_attr.index = k;
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 	}
344 
345 	res = device_create_file(&pdev->dev, &dev_attr_name);
346 	if (res)
347 		goto exit_remove;
348 
349 	data->hwmon_dev = hwmon_device_register(&pdev->dev);
350 	if (IS_ERR(data->hwmon_dev)) {
351 		res = PTR_ERR(data->hwmon_dev);
352 		goto exit_remove;
353 	}
354 
355 	return res;
356 
357 exit_remove:
358 	device_remove_file(&pdev->dev, &dev_attr_name);
359 	for (i = 0; i < data->num_attrs; i++)
360 		device_remove_file(&pdev->dev, &data->attrs[i].s_attr.dev_attr);
361 	kfree(data->attrs);
362 
363 	return res;
364 }
365 
366 static int __devinit i5k_amb_add(void)
367 {
368 	int res = -ENODEV;
369 
370 	/* only ever going to be one of these */
371 	amb_pdev = platform_device_alloc(DRVNAME, 0);
372 	if (!amb_pdev)
373 		return -ENOMEM;
374 
375 	res = platform_device_add(amb_pdev);
376 	if (res)
377 		goto err;
378 	return 0;
379 
380 err:
381 	platform_device_put(amb_pdev);
382 	return res;
383 }
384 
385 static int __devinit i5k_find_amb_registers(struct i5k_amb_data *data)
386 {
387 	struct pci_dev *pcidev;
388 	u32 val32;
389 	int res = -ENODEV;
390 
391 	/* Find AMB register memory space */
392 	pcidev = pci_get_device(PCI_VENDOR_ID_INTEL,
393 				PCI_DEVICE_ID_INTEL_5000_ERR,
394 				NULL);
395 	if (!pcidev)
396 		return -ENODEV;
397 
398 	if (pci_read_config_dword(pcidev, I5K_REG_AMB_BASE_ADDR, &val32))
399 		goto out;
400 	data->amb_base = val32;
401 
402 	if (pci_read_config_dword(pcidev, I5K_REG_AMB_LEN_ADDR, &val32))
403 		goto out;
404 	data->amb_len = val32;
405 
406 	/* Is it big enough? */
407 	if (data->amb_len < AMB_CONFIG_SIZE * MAX_AMBS) {
408 		dev_err(&pcidev->dev, "AMB region too small!\n");
409 		goto out;
410 	}
411 
412 	res = 0;
413 out:
414 	pci_dev_put(pcidev);
415 	return res;
416 }
417 
418 static int __devinit i5k_channel_probe(u16 *amb_present, unsigned long dev_id)
419 {
420 	struct pci_dev *pcidev;
421 	u16 val16;
422 	int res = -ENODEV;
423 
424 	/* Copy the DIMM presence map for these two channels */
425 	pcidev = pci_get_device(PCI_VENDOR_ID_INTEL, dev_id, NULL);
426 	if (!pcidev)
427 		return -ENODEV;
428 
429 	if (pci_read_config_word(pcidev, I5K_REG_CHAN0_PRESENCE_ADDR, &val16))
430 		goto out;
431 	amb_present[0] = val16;
432 
433 	if (pci_read_config_word(pcidev, I5K_REG_CHAN1_PRESENCE_ADDR, &val16))
434 		goto out;
435 	amb_present[1] = val16;
436 
437 	res = 0;
438 
439 out:
440 	pci_dev_put(pcidev);
441 	return res;
442 }
443 
444 static int __devinit i5k_amb_probe(struct platform_device *pdev)
445 {
446 	struct i5k_amb_data *data;
447 	struct resource *reso;
448 	int res = -ENODEV;
449 
450 	data = kzalloc(sizeof(*data), GFP_KERNEL);
451 	if (!data)
452 		return -ENOMEM;
453 
454 	/* Figure out where the AMB registers live */
455 	res = i5k_find_amb_registers(data);
456 	if (res)
457 		goto err;
458 
459 	/* Copy the DIMM presence map for the first two channels */
460 	res = i5k_channel_probe(&data->amb_present[0],
461 				PCI_DEVICE_ID_INTEL_5000_FBD0);
462 	if (res)
463 		goto err;
464 
465 	/* Copy the DIMM presence map for the optional second two channels */
466 	i5k_channel_probe(&data->amb_present[2],
467 			  PCI_DEVICE_ID_INTEL_5000_FBD1);
468 
469 	/* Set up resource regions */
470 	reso = request_mem_region(data->amb_base, data->amb_len, DRVNAME);
471 	if (!reso) {
472 		res = -EBUSY;
473 		goto err;
474 	}
475 
476 	data->amb_mmio = ioremap_nocache(data->amb_base, data->amb_len);
477 	if (!data->amb_mmio) {
478 		res = -EBUSY;
479 		goto err_map_failed;
480 	}
481 
482 	platform_set_drvdata(pdev, data);
483 
484 	res = i5k_amb_hwmon_init(pdev);
485 	if (res)
486 		goto err_init_failed;
487 
488 	return res;
489 
490 err_init_failed:
491 	iounmap(data->amb_mmio);
492 	platform_set_drvdata(pdev, NULL);
493 err_map_failed:
494 	release_mem_region(data->amb_base, data->amb_len);
495 err:
496 	kfree(data);
497 	return res;
498 }
499 
500 static int __devexit i5k_amb_remove(struct platform_device *pdev)
501 {
502 	int i;
503 	struct i5k_amb_data *data = platform_get_drvdata(pdev);
504 
505 	hwmon_device_unregister(data->hwmon_dev);
506 	device_remove_file(&pdev->dev, &dev_attr_name);
507 	for (i = 0; i < data->num_attrs; i++)
508 		device_remove_file(&pdev->dev, &data->attrs[i].s_attr.dev_attr);
509 	kfree(data->attrs);
510 	iounmap(data->amb_mmio);
511 	release_mem_region(data->amb_base, data->amb_len);
512 	platform_set_drvdata(pdev, NULL);
513 	kfree(data);
514 	return 0;
515 }
516 
517 static struct platform_driver i5k_amb_driver = {
518 	.driver = {
519 		.owner = THIS_MODULE,
520 		.name = DRVNAME,
521 	},
522 	.probe = i5k_amb_probe,
523 	.remove = __devexit_p(i5k_amb_remove),
524 };
525 
526 static int __init i5k_amb_init(void)
527 {
528 	int res;
529 
530 	res = platform_driver_register(&i5k_amb_driver);
531 	if (res)
532 		return res;
533 
534 	res = i5k_amb_add();
535 	if (res)
536 		platform_driver_unregister(&i5k_amb_driver);
537 
538 	return res;
539 }
540 
541 static void __exit i5k_amb_exit(void)
542 {
543 	platform_device_unregister(amb_pdev);
544 	platform_driver_unregister(&i5k_amb_driver);
545 }
546 
547 MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
548 MODULE_DESCRIPTION("Intel 5000 chipset FB-DIMM AMB temperature sensor");
549 MODULE_LICENSE("GPL");
550 
551 module_init(i5k_amb_init);
552 module_exit(i5k_amb_exit);
553