xref: /openbmc/linux/drivers/hwmon/gsc-hwmon.c (revision b737eecd)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Driver for Gateworks System Controller Hardware Monitor module
4  *
5  * Copyright (C) 2020 Gateworks Corporation
6  */
7 #include <linux/hwmon.h>
8 #include <linux/hwmon-sysfs.h>
9 #include <linux/mfd/gsc.h>
10 #include <linux/module.h>
11 #include <linux/of.h>
12 #include <linux/platform_device.h>
13 #include <linux/regmap.h>
14 #include <linux/slab.h>
15 
16 #include <linux/platform_data/gsc_hwmon.h>
17 
18 #define GSC_HWMON_MAX_TEMP_CH	16
19 #define GSC_HWMON_MAX_IN_CH	16
20 #define GSC_HWMON_MAX_FAN_CH	16
21 
22 #define GSC_HWMON_RESOLUTION	12
23 #define GSC_HWMON_VREF		2500
24 
25 struct gsc_hwmon_data {
26 	struct gsc_dev *gsc;
27 	struct gsc_hwmon_platform_data *pdata;
28 	struct regmap *regmap;
29 	const struct gsc_hwmon_channel *temp_ch[GSC_HWMON_MAX_TEMP_CH];
30 	const struct gsc_hwmon_channel *in_ch[GSC_HWMON_MAX_IN_CH];
31 	const struct gsc_hwmon_channel *fan_ch[GSC_HWMON_MAX_FAN_CH];
32 	u32 temp_config[GSC_HWMON_MAX_TEMP_CH + 1];
33 	u32 in_config[GSC_HWMON_MAX_IN_CH + 1];
34 	u32 fan_config[GSC_HWMON_MAX_FAN_CH + 1];
35 	struct hwmon_channel_info temp_info;
36 	struct hwmon_channel_info in_info;
37 	struct hwmon_channel_info fan_info;
38 	const struct hwmon_channel_info *info[4];
39 	struct hwmon_chip_info chip;
40 };
41 
42 static struct regmap_bus gsc_hwmon_regmap_bus = {
43 	.reg_read = gsc_read,
44 	.reg_write = gsc_write,
45 };
46 
47 static const struct regmap_config gsc_hwmon_regmap_config = {
48 	.reg_bits = 8,
49 	.val_bits = 8,
50 	.cache_type = REGCACHE_NONE,
51 };
52 
53 static ssize_t pwm_auto_point_temp_show(struct device *dev,
54 					struct device_attribute *devattr,
55 					char *buf)
56 {
57 	struct gsc_hwmon_data *hwmon = dev_get_drvdata(dev);
58 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
59 	u8 reg = hwmon->pdata->fan_base + (2 * attr->index);
60 	u8 regs[2];
61 	int ret;
62 
63 	ret = regmap_bulk_read(hwmon->regmap, reg, regs, 2);
64 	if (ret)
65 		return ret;
66 
67 	ret = regs[0] | regs[1] << 8;
68 	return sprintf(buf, "%d\n", ret * 10);
69 }
70 
71 static ssize_t pwm_auto_point_temp_store(struct device *dev,
72 					 struct device_attribute *devattr,
73 					 const char *buf, size_t count)
74 {
75 	struct gsc_hwmon_data *hwmon = dev_get_drvdata(dev);
76 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
77 	u8 reg = hwmon->pdata->fan_base + (2 * attr->index);
78 	u8 regs[2];
79 	long temp;
80 	int err;
81 
82 	if (kstrtol(buf, 10, &temp))
83 		return -EINVAL;
84 
85 	temp = clamp_val(temp, 0, 10000);
86 	temp = DIV_ROUND_CLOSEST(temp, 10);
87 
88 	regs[0] = temp & 0xff;
89 	regs[1] = (temp >> 8) & 0xff;
90 	err = regmap_bulk_write(hwmon->regmap, reg, regs, 2);
91 	if (err)
92 		return err;
93 
94 	return count;
95 }
96 
97 static ssize_t pwm_auto_point_pwm_show(struct device *dev,
98 				       struct device_attribute *devattr,
99 				       char *buf)
100 {
101 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
102 
103 	return sprintf(buf, "%d\n", 255 * (50 + (attr->index * 10)) / 100);
104 }
105 
106 static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point1_pwm, pwm_auto_point_pwm, 0);
107 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point1_temp, pwm_auto_point_temp, 0);
108 
109 static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point2_pwm, pwm_auto_point_pwm, 1);
110 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point2_temp, pwm_auto_point_temp, 1);
111 
112 static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point3_pwm, pwm_auto_point_pwm, 2);
113 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point3_temp, pwm_auto_point_temp, 2);
114 
115 static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point4_pwm, pwm_auto_point_pwm, 3);
116 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point4_temp, pwm_auto_point_temp, 3);
117 
118 static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point5_pwm, pwm_auto_point_pwm, 4);
119 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point5_temp, pwm_auto_point_temp, 4);
120 
121 static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point6_pwm, pwm_auto_point_pwm, 5);
122 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point6_temp, pwm_auto_point_temp, 5);
123 
124 static struct attribute *gsc_hwmon_attributes[] = {
125 	&sensor_dev_attr_pwm1_auto_point1_pwm.dev_attr.attr,
126 	&sensor_dev_attr_pwm1_auto_point1_temp.dev_attr.attr,
127 	&sensor_dev_attr_pwm1_auto_point2_pwm.dev_attr.attr,
128 	&sensor_dev_attr_pwm1_auto_point2_temp.dev_attr.attr,
129 	&sensor_dev_attr_pwm1_auto_point3_pwm.dev_attr.attr,
130 	&sensor_dev_attr_pwm1_auto_point3_temp.dev_attr.attr,
131 	&sensor_dev_attr_pwm1_auto_point4_pwm.dev_attr.attr,
132 	&sensor_dev_attr_pwm1_auto_point4_temp.dev_attr.attr,
133 	&sensor_dev_attr_pwm1_auto_point5_pwm.dev_attr.attr,
134 	&sensor_dev_attr_pwm1_auto_point5_temp.dev_attr.attr,
135 	&sensor_dev_attr_pwm1_auto_point6_pwm.dev_attr.attr,
136 	&sensor_dev_attr_pwm1_auto_point6_temp.dev_attr.attr,
137 	NULL
138 };
139 
140 static const struct attribute_group gsc_hwmon_group = {
141 	.attrs = gsc_hwmon_attributes,
142 };
143 __ATTRIBUTE_GROUPS(gsc_hwmon);
144 
145 static int
146 gsc_hwmon_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
147 	       int channel, long *val)
148 {
149 	struct gsc_hwmon_data *hwmon = dev_get_drvdata(dev);
150 	const struct gsc_hwmon_channel *ch;
151 	int sz, ret;
152 	long tmp;
153 	u8 buf[3];
154 
155 	switch (type) {
156 	case hwmon_in:
157 		ch = hwmon->in_ch[channel];
158 		break;
159 	case hwmon_temp:
160 		ch = hwmon->temp_ch[channel];
161 		break;
162 	case hwmon_fan:
163 		ch = hwmon->fan_ch[channel];
164 		break;
165 	default:
166 		return -EOPNOTSUPP;
167 	}
168 
169 	sz = (ch->mode == mode_voltage_24bit) ? 3 : 2;
170 	ret = regmap_bulk_read(hwmon->regmap, ch->reg, buf, sz);
171 	if (ret)
172 		return ret;
173 
174 	tmp = 0;
175 	while (sz-- > 0)
176 		tmp |= (buf[sz] << (8 * sz));
177 
178 	switch (ch->mode) {
179 	case mode_temperature:
180 		if (tmp > 0x8000)
181 			tmp -= 0xffff;
182 		tmp *= 100; /* convert to millidegrees celsius */
183 		break;
184 	case mode_voltage_raw:
185 		tmp = clamp_val(tmp, 0, BIT(GSC_HWMON_RESOLUTION));
186 		/* scale based on ref voltage and ADC resolution */
187 		tmp *= GSC_HWMON_VREF;
188 		tmp >>= GSC_HWMON_RESOLUTION;
189 		/* scale based on optional voltage divider */
190 		if (ch->vdiv[0] && ch->vdiv[1]) {
191 			tmp *= (ch->vdiv[0] + ch->vdiv[1]);
192 			tmp /= ch->vdiv[1];
193 		}
194 		/* adjust by uV offset */
195 		tmp += ch->mvoffset;
196 		break;
197 	case mode_fan:
198 		tmp *= 30; /* convert to revolutions per minute */
199 		break;
200 	case mode_voltage_24bit:
201 	case mode_voltage_16bit:
202 		/* no adjustment needed */
203 		break;
204 	}
205 
206 	*val = tmp;
207 
208 	return 0;
209 }
210 
211 static int
212 gsc_hwmon_read_string(struct device *dev, enum hwmon_sensor_types type,
213 		      u32 attr, int channel, const char **buf)
214 {
215 	struct gsc_hwmon_data *hwmon = dev_get_drvdata(dev);
216 
217 	switch (type) {
218 	case hwmon_in:
219 		*buf = hwmon->in_ch[channel]->name;
220 		break;
221 	case hwmon_temp:
222 		*buf = hwmon->temp_ch[channel]->name;
223 		break;
224 	case hwmon_fan:
225 		*buf = hwmon->fan_ch[channel]->name;
226 		break;
227 	default:
228 		return -ENOTSUPP;
229 	}
230 
231 	return 0;
232 }
233 
234 static umode_t
235 gsc_hwmon_is_visible(const void *_data, enum hwmon_sensor_types type, u32 attr,
236 		     int ch)
237 {
238 	return 0444;
239 }
240 
241 static const struct hwmon_ops gsc_hwmon_ops = {
242 	.is_visible = gsc_hwmon_is_visible,
243 	.read = gsc_hwmon_read,
244 	.read_string = gsc_hwmon_read_string,
245 };
246 
247 static struct gsc_hwmon_platform_data *
248 gsc_hwmon_get_devtree_pdata(struct device *dev)
249 {
250 	struct gsc_hwmon_platform_data *pdata;
251 	struct gsc_hwmon_channel *ch;
252 	struct fwnode_handle *child;
253 	struct device_node *fan;
254 	int nchannels;
255 
256 	nchannels = device_get_child_node_count(dev);
257 	if (nchannels == 0)
258 		return ERR_PTR(-ENODEV);
259 
260 	pdata = devm_kzalloc(dev,
261 			     sizeof(*pdata) + nchannels * sizeof(*ch),
262 			     GFP_KERNEL);
263 	if (!pdata)
264 		return ERR_PTR(-ENOMEM);
265 	ch = (struct gsc_hwmon_channel *)(pdata + 1);
266 	pdata->channels = ch;
267 	pdata->nchannels = nchannels;
268 
269 	/* fan controller base address */
270 	fan = of_find_compatible_node(dev->parent->of_node, NULL, "gw,gsc-fan");
271 	if (fan && of_property_read_u32(fan, "reg", &pdata->fan_base)) {
272 		dev_err(dev, "fan node without base\n");
273 		return ERR_PTR(-EINVAL);
274 	}
275 
276 	/* allocate structures for channels and count instances of each type */
277 	device_for_each_child_node(dev, child) {
278 		if (fwnode_property_read_string(child, "label", &ch->name)) {
279 			dev_err(dev, "channel without label\n");
280 			fwnode_handle_put(child);
281 			return ERR_PTR(-EINVAL);
282 		}
283 		if (fwnode_property_read_u32(child, "reg", &ch->reg)) {
284 			dev_err(dev, "channel without reg\n");
285 			fwnode_handle_put(child);
286 			return ERR_PTR(-EINVAL);
287 		}
288 		if (fwnode_property_read_u32(child, "gw,mode", &ch->mode)) {
289 			dev_err(dev, "channel without mode\n");
290 			fwnode_handle_put(child);
291 			return ERR_PTR(-EINVAL);
292 		}
293 		if (ch->mode > mode_max) {
294 			dev_err(dev, "invalid channel mode\n");
295 			fwnode_handle_put(child);
296 			return ERR_PTR(-EINVAL);
297 		}
298 
299 		if (!fwnode_property_read_u32(child,
300 					      "gw,voltage-offset-microvolt",
301 					      &ch->mvoffset))
302 			ch->mvoffset /= 1000;
303 		fwnode_property_read_u32_array(child,
304 					       "gw,voltage-divider-ohms",
305 					       ch->vdiv, ARRAY_SIZE(ch->vdiv));
306 		ch++;
307 	}
308 
309 	return pdata;
310 }
311 
312 static int gsc_hwmon_probe(struct platform_device *pdev)
313 {
314 	struct gsc_dev *gsc = dev_get_drvdata(pdev->dev.parent);
315 	struct device *dev = &pdev->dev;
316 	struct device *hwmon_dev;
317 	struct gsc_hwmon_platform_data *pdata = dev_get_platdata(dev);
318 	struct gsc_hwmon_data *hwmon;
319 	const struct attribute_group **groups;
320 	int i, i_in, i_temp, i_fan;
321 
322 	if (!pdata) {
323 		pdata = gsc_hwmon_get_devtree_pdata(dev);
324 		if (IS_ERR(pdata))
325 			return PTR_ERR(pdata);
326 	}
327 
328 	hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL);
329 	if (!hwmon)
330 		return -ENOMEM;
331 	hwmon->gsc = gsc;
332 	hwmon->pdata = pdata;
333 
334 	hwmon->regmap = devm_regmap_init(dev, &gsc_hwmon_regmap_bus,
335 					 gsc->i2c_hwmon,
336 					 &gsc_hwmon_regmap_config);
337 	if (IS_ERR(hwmon->regmap))
338 		return PTR_ERR(hwmon->regmap);
339 
340 	for (i = 0, i_in = 0, i_temp = 0, i_fan = 0; i < hwmon->pdata->nchannels; i++) {
341 		const struct gsc_hwmon_channel *ch = &pdata->channels[i];
342 
343 		switch (ch->mode) {
344 		case mode_temperature:
345 			if (i_temp == GSC_HWMON_MAX_TEMP_CH) {
346 				dev_err(gsc->dev, "too many temp channels\n");
347 				return -EINVAL;
348 			}
349 			hwmon->temp_ch[i_temp] = ch;
350 			hwmon->temp_config[i_temp] = HWMON_T_INPUT |
351 						     HWMON_T_LABEL;
352 			i_temp++;
353 			break;
354 		case mode_fan:
355 			if (i_fan == GSC_HWMON_MAX_FAN_CH) {
356 				dev_err(gsc->dev, "too many fan channels\n");
357 				return -EINVAL;
358 			}
359 			hwmon->fan_ch[i_fan] = ch;
360 			hwmon->fan_config[i_fan] = HWMON_F_INPUT |
361 						   HWMON_F_LABEL;
362 			i_fan++;
363 			break;
364 		case mode_voltage_24bit:
365 		case mode_voltage_16bit:
366 		case mode_voltage_raw:
367 			if (i_in == GSC_HWMON_MAX_IN_CH) {
368 				dev_err(gsc->dev, "too many input channels\n");
369 				return -EINVAL;
370 			}
371 			hwmon->in_ch[i_in] = ch;
372 			hwmon->in_config[i_in] =
373 				HWMON_I_INPUT | HWMON_I_LABEL;
374 			i_in++;
375 			break;
376 		default:
377 			dev_err(gsc->dev, "invalid mode: %d\n", ch->mode);
378 			return -EINVAL;
379 		}
380 	}
381 
382 	/* setup config structures */
383 	hwmon->chip.ops = &gsc_hwmon_ops;
384 	hwmon->chip.info = hwmon->info;
385 	hwmon->info[0] = &hwmon->temp_info;
386 	hwmon->info[1] = &hwmon->in_info;
387 	hwmon->info[2] = &hwmon->fan_info;
388 	hwmon->temp_info.type = hwmon_temp;
389 	hwmon->temp_info.config = hwmon->temp_config;
390 	hwmon->in_info.type = hwmon_in;
391 	hwmon->in_info.config = hwmon->in_config;
392 	hwmon->fan_info.type = hwmon_fan;
393 	hwmon->fan_info.config = hwmon->fan_config;
394 
395 	groups = pdata->fan_base ? gsc_hwmon_groups : NULL;
396 	hwmon_dev = devm_hwmon_device_register_with_info(dev,
397 							 KBUILD_MODNAME, hwmon,
398 							 &hwmon->chip, groups);
399 	return PTR_ERR_OR_ZERO(hwmon_dev);
400 }
401 
402 static const struct of_device_id gsc_hwmon_of_match[] = {
403 	{ .compatible = "gw,gsc-adc", },
404 	{}
405 };
406 
407 static struct platform_driver gsc_hwmon_driver = {
408 	.driver = {
409 		.name = "gsc-hwmon",
410 		.of_match_table = gsc_hwmon_of_match,
411 	},
412 	.probe = gsc_hwmon_probe,
413 };
414 
415 module_platform_driver(gsc_hwmon_driver);
416 
417 MODULE_AUTHOR("Tim Harvey <tharvey@gateworks.com>");
418 MODULE_DESCRIPTION("GSC hardware monitor driver");
419 MODULE_LICENSE("GPL v2");
420