1/*
  2 * IBM PowerNV platform sensors for temperature/fan/voltage/power
  3 * Copyright (C) 2014 IBM
  4 *
  5 * This program is free software; you can redistribute it and/or modify
  6 * it under the terms of the GNU General Public License as published by
  7 * the Free Software Foundation; either version 2 of the License, or
  8 * (at your option) any later version.
  9 *
 10 * This program is distributed in the hope that it will be useful,
 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13 * GNU General Public License for more details.
 14 *
 15 * You should have received a copy of the GNU General Public License
 16 * along with this program.
 17 */
 18
 19#define DRVNAME		"ibmpowernv"
 20#define pr_fmt(fmt)	DRVNAME ": " fmt
 21
 22#include <linux/init.h>
 23#include <linux/module.h>
 24#include <linux/kernel.h>
 25#include <linux/hwmon.h>
 26#include <linux/hwmon-sysfs.h>
 27#include <linux/of.h>
 28#include <linux/slab.h>
 29
 30#include <linux/platform_device.h>
 31#include <asm/opal.h>
 32#include <linux/err.h>
 33#include <asm/cputhreads.h>
 34#include <asm/smp.h>
 35
 36#define MAX_ATTR_LEN	32
 37#define MAX_LABEL_LEN	64
 38
 39/* Sensor suffix name from DT */
 40#define DT_FAULT_ATTR_SUFFIX		"faulted"
 41#define DT_DATA_ATTR_SUFFIX		"data"
 42#define DT_THRESHOLD_ATTR_SUFFIX	"thrs"
 43
 44/*
 45 * Enumerates all the types of sensors in the POWERNV platform and does index
 46 * into 'struct sensor_group'
 47 */
 48enum sensors {
 49	FAN,
 50	TEMP,
 51	POWER_SUPPLY,
 52	POWER_INPUT,
 53	MAX_SENSOR_TYPE,
 54};
 55
 56#define INVALID_INDEX (-1U)
 57
 58static struct sensor_group {
 59	const char *name;
 60	const char *compatible;
 61	struct attribute_group group;
 62	u32 attr_count;
 63	u32 hwmon_index;
 64} sensor_groups[] = {
 65	{"fan", "ibm,opal-sensor-cooling-fan"},
 66	{"temp", "ibm,opal-sensor-amb-temp"},
 67	{"in", "ibm,opal-sensor-power-supply"},
 68	{"power", "ibm,opal-sensor-power"}
 69};
 70
 71struct sensor_data {
 72	u32 id; /* An opaque id of the firmware for each sensor */
 73	u32 hwmon_index;
 74	u32 opal_index;
 75	enum sensors type;
 76	char label[MAX_LABEL_LEN];
 77	char name[MAX_ATTR_LEN];
 78	struct device_attribute dev_attr;
 79};
 80
 81struct platform_data {
 82	const struct attribute_group *attr_groups[MAX_SENSOR_TYPE + 1];
 83	u32 sensors_count; /* Total count of sensors from each group */
 84};
 85
 86static ssize_t show_sensor(struct device *dev, struct device_attribute *devattr,
 87			   char *buf)
 88{
 89	struct sensor_data *sdata = container_of(devattr, struct sensor_data,
 90						 dev_attr);
 91	ssize_t ret;
 92	u32 x;
 93
 94	ret = opal_get_sensor_data(sdata->id, &x);
 95	if (ret)
 96		return ret;
 97
 98	/* Convert temperature to milli-degrees */
 99	if (sdata->type == TEMP)
100		x *= 1000;
101	/* Convert power to micro-watts */
102	else if (sdata->type == POWER_INPUT)
103		x *= 1000000;
104
105	return sprintf(buf, "%u\n", x);
106}
107
108static ssize_t show_label(struct device *dev, struct device_attribute *devattr,
109			  char *buf)
110{
111	struct sensor_data *sdata = container_of(devattr, struct sensor_data,
112						 dev_attr);
113
114	return sprintf(buf, "%s\n", sdata->label);
115}
116
117static int __init get_logical_cpu(int hwcpu)
118{
119	int cpu;
120
121	for_each_possible_cpu(cpu)
122		if (get_hard_smp_processor_id(cpu) == hwcpu)
123			return cpu;
124
125	return -ENOENT;
126}
127
128static void __init make_sensor_label(struct device_node *np,
129				     struct sensor_data *sdata,
130				     const char *label)
131{
132	u32 id;
133	size_t n;
134
135	n = snprintf(sdata->label, sizeof(sdata->label), "%s", label);
136
137	/*
138	 * Core temp pretty print
139	 */
140	if (!of_property_read_u32(np, "ibm,pir", &id)) {
141		int cpuid = get_logical_cpu(id);
142
143		if (cpuid >= 0)
144			/*
145			 * The digital thermal sensors are associated
146			 * with a core.
147			 */
148			n += snprintf(sdata->label + n,
149				      sizeof(sdata->label) - n, " %d",
150				      cpuid);
151		else
152			n += snprintf(sdata->label + n,
153				      sizeof(sdata->label) - n, " phy%d", id);
154	}
155
156	/*
157	 * Membuffer pretty print
158	 */
159	if (!of_property_read_u32(np, "ibm,chip-id", &id))
160		n += snprintf(sdata->label + n, sizeof(sdata->label) - n,
161			      " %d", id & 0xffff);
162}
163
164static int get_sensor_index_attr(const char *name, u32 *index, char *attr)
165{
166	char *hash_pos = strchr(name, '#');
167	char buf[8] = { 0 };
168	char *dash_pos;
169	u32 copy_len;
170	int err;
171
172	if (!hash_pos)
173		return -EINVAL;
174
175	dash_pos = strchr(hash_pos, '-');
176	if (!dash_pos)
177		return -EINVAL;
178
179	copy_len = dash_pos - hash_pos - 1;
180	if (copy_len >= sizeof(buf))
181		return -EINVAL;
182
183	strncpy(buf, hash_pos + 1, copy_len);
184
185	err = kstrtou32(buf, 10, index);
186	if (err)
187		return err;
188
189	strncpy(attr, dash_pos + 1, MAX_ATTR_LEN);
190
191	return 0;
192}
193
194static const char *convert_opal_attr_name(enum sensors type,
195					  const char *opal_attr)
196{
197	const char *attr_name = NULL;
198
199	if (!strcmp(opal_attr, DT_FAULT_ATTR_SUFFIX)) {
200		attr_name = "fault";
201	} else if (!strcmp(opal_attr, DT_DATA_ATTR_SUFFIX)) {
202		attr_name = "input";
203	} else if (!strcmp(opal_attr, DT_THRESHOLD_ATTR_SUFFIX)) {
204		if (type == TEMP)
205			attr_name = "max";
206		else if (type == FAN)
207			attr_name = "min";
208	}
209
210	return attr_name;
211}
212
213/*
214 * This function translates the DT node name into the 'hwmon' attribute name.
215 * IBMPOWERNV device node appear like cooling-fan#2-data, amb-temp#1-thrs etc.
216 * which need to be mapped as fan2_input, temp1_max respectively before
217 * populating them inside hwmon device class.
218 */
219static const char *parse_opal_node_name(const char *node_name,
220					enum sensors type, u32 *index)
221{
222	char attr_suffix[MAX_ATTR_LEN];
223	const char *attr_name;
224	int err;
225
226	err = get_sensor_index_attr(node_name, index, attr_suffix);
227	if (err)
228		return ERR_PTR(err);
229
230	attr_name = convert_opal_attr_name(type, attr_suffix);
231	if (!attr_name)
232		return ERR_PTR(-ENOENT);
233
234	return attr_name;
235}
236
237static int get_sensor_type(struct device_node *np)
238{
239	enum sensors type;
240	const char *str;
241
242	for (type = 0; type < MAX_SENSOR_TYPE; type++) {
243		if (of_device_is_compatible(np, sensor_groups[type].compatible))
244			return type;
245	}
246
247	/*
248	 * Let's check if we have a newer device tree
249	 */
250	if (!of_device_is_compatible(np, "ibm,opal-sensor"))
251		return MAX_SENSOR_TYPE;
252
253	if (of_property_read_string(np, "sensor-type", &str))
254		return MAX_SENSOR_TYPE;
255
256	for (type = 0; type < MAX_SENSOR_TYPE; type++)
257		if (!strcmp(str, sensor_groups[type].name))
258			return type;
259
260	return MAX_SENSOR_TYPE;
261}
262
263static u32 get_sensor_hwmon_index(struct sensor_data *sdata,
264				  struct sensor_data *sdata_table, int count)
265{
266	int i;
267
268	/*
269	 * We don't use the OPAL index on newer device trees
270	 */
271	if (sdata->opal_index != INVALID_INDEX) {
272		for (i = 0; i < count; i++)
273			if (sdata_table[i].opal_index == sdata->opal_index &&
274			    sdata_table[i].type == sdata->type)
275				return sdata_table[i].hwmon_index;
276	}
277	return ++sensor_groups[sdata->type].hwmon_index;
278}
279
280static int populate_attr_groups(struct platform_device *pdev)
281{
282	struct platform_data *pdata = platform_get_drvdata(pdev);
283	const struct attribute_group **pgroups = pdata->attr_groups;
284	struct device_node *opal, *np;
285	enum sensors type;
286
287	opal = of_find_node_by_path("/ibm,opal/sensors");
288	for_each_child_of_node(opal, np) {
289		const char *label;
290
291		if (np->name == NULL)
292			continue;
293
294		type = get_sensor_type(np);
295		if (type == MAX_SENSOR_TYPE)
296			continue;
297
298		sensor_groups[type].attr_count++;
299
300		/*
301		 * add a new attribute for labels
302		 */
303		if (!of_property_read_string(np, "label", &label))
304			sensor_groups[type].attr_count++;
305	}
306
307	of_node_put(opal);
308
309	for (type = 0; type < MAX_SENSOR_TYPE; type++) {
310		sensor_groups[type].group.attrs = devm_kzalloc(&pdev->dev,
311					sizeof(struct attribute *) *
312					(sensor_groups[type].attr_count + 1),
313					GFP_KERNEL);
314		if (!sensor_groups[type].group.attrs)
315			return -ENOMEM;
316
317		pgroups[type] = &sensor_groups[type].group;
318		pdata->sensors_count += sensor_groups[type].attr_count;
319		sensor_groups[type].attr_count = 0;
320	}
321
322	return 0;
323}
324
325static void create_hwmon_attr(struct sensor_data *sdata, const char *attr_name,
326			      ssize_t (*show)(struct device *dev,
327					      struct device_attribute *attr,
328					      char *buf))
329{
330	snprintf(sdata->name, MAX_ATTR_LEN, "%s%d_%s",
331		 sensor_groups[sdata->type].name, sdata->hwmon_index,
332		 attr_name);
333
334	sysfs_attr_init(&sdata->dev_attr.attr);
335	sdata->dev_attr.attr.name = sdata->name;
336	sdata->dev_attr.attr.mode = S_IRUGO;
337	sdata->dev_attr.show = show;
338}
339
340/*
341 * Iterate through the device tree for each child of 'sensors' node, create
342 * a sysfs attribute file, the file is named by translating the DT node name
343 * to the name required by the higher 'hwmon' driver like fan1_input, temp1_max
344 * etc..
345 */
346static int create_device_attrs(struct platform_device *pdev)
347{
348	struct platform_data *pdata = platform_get_drvdata(pdev);
349	const struct attribute_group **pgroups = pdata->attr_groups;
350	struct device_node *opal, *np;
351	struct sensor_data *sdata;
352	u32 sensor_id;
353	enum sensors type;
354	u32 count = 0;
355	int err = 0;
356
357	opal = of_find_node_by_path("/ibm,opal/sensors");
358	sdata = devm_kzalloc(&pdev->dev, pdata->sensors_count * sizeof(*sdata),
359			     GFP_KERNEL);
360	if (!sdata) {
361		err = -ENOMEM;
362		goto exit_put_node;
363	}
364
365	for_each_child_of_node(opal, np) {
366		const char *attr_name;
367		u32 opal_index;
368		const char *label;
369
370		if (np->name == NULL)
371			continue;
372
373		type = get_sensor_type(np);
374		if (type == MAX_SENSOR_TYPE)
375			continue;
376
377		/*
378		 * Newer device trees use a "sensor-data" property
379		 * name for input.
380		 */
381		if (of_property_read_u32(np, "sensor-id", &sensor_id) &&
382		    of_property_read_u32(np, "sensor-data", &sensor_id)) {
383			dev_info(&pdev->dev,
384				 "'sensor-id' missing in the node '%s'\n",
385				 np->name);
386			continue;
387		}
388
389		sdata[count].id = sensor_id;
390		sdata[count].type = type;
391
392		/*
393		 * If we can not parse the node name, it means we are
394		 * running on a newer device tree. We can just forget
395		 * about the OPAL index and use a defaut value for the
396		 * hwmon attribute name
397		 */
398		attr_name = parse_opal_node_name(np->name, type, &opal_index);
399		if (IS_ERR(attr_name)) {
400			attr_name = "input";
401			opal_index = INVALID_INDEX;
402		}
403
404		sdata[count].opal_index = opal_index;
405		sdata[count].hwmon_index =
406			get_sensor_hwmon_index(&sdata[count], sdata, count);
407
408		create_hwmon_attr(&sdata[count], attr_name, show_sensor);
409
410		pgroups[type]->attrs[sensor_groups[type].attr_count++] =
411				&sdata[count++].dev_attr.attr;
412
413		if (!of_property_read_string(np, "label", &label)) {
414			/*
415			 * For the label attribute, we can reuse the
416			 * "properties" of the previous "input"
417			 * attribute. They are related to the same
418			 * sensor.
419			 */
420			sdata[count].type = type;
421			sdata[count].opal_index = sdata[count - 1].opal_index;
422			sdata[count].hwmon_index = sdata[count - 1].hwmon_index;
423
424			make_sensor_label(np, &sdata[count], label);
425
426			create_hwmon_attr(&sdata[count], "label", show_label);
427
428			pgroups[type]->attrs[sensor_groups[type].attr_count++] =
429				&sdata[count++].dev_attr.attr;
430		}
431	}
432
433exit_put_node:
434	of_node_put(opal);
435	return err;
436}
437
438static int ibmpowernv_probe(struct platform_device *pdev)
439{
440	struct platform_data *pdata;
441	struct device *hwmon_dev;
442	int err;
443
444	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
445	if (!pdata)
446		return -ENOMEM;
447
448	platform_set_drvdata(pdev, pdata);
449	pdata->sensors_count = 0;
450	err = populate_attr_groups(pdev);
451	if (err)
452		return err;
453
454	/* Create sysfs attribute data for each sensor found in the DT */
455	err = create_device_attrs(pdev);
456	if (err)
457		return err;
458
459	/* Finally, register with hwmon */
460	hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev, DRVNAME,
461							   pdata,
462							   pdata->attr_groups);
463
464	return PTR_ERR_OR_ZERO(hwmon_dev);
465}
466
467static const struct platform_device_id opal_sensor_driver_ids[] = {
468	{
469		.name = "opal-sensor",
470	},
471	{ }
472};
473MODULE_DEVICE_TABLE(platform, opal_sensor_driver_ids);
474
475static const struct of_device_id opal_sensor_match[] = {
476	{ .compatible	= "ibm,opal-sensor" },
477	{ },
478};
479MODULE_DEVICE_TABLE(of, opal_sensor_match);
480
481static struct platform_driver ibmpowernv_driver = {
482	.probe		= ibmpowernv_probe,
483	.id_table	= opal_sensor_driver_ids,
484	.driver		= {
485		.name	= DRVNAME,
486		.of_match_table	= opal_sensor_match,
487	},
488};
489
490module_platform_driver(ibmpowernv_driver);
491
492MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>");
493MODULE_DESCRIPTION("IBM POWERNV platform sensors");
494MODULE_LICENSE("GPL");