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 const 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 };
51 
52 static ssize_t pwm_auto_point_temp_show(struct device *dev,
53 					struct device_attribute *devattr,
54 					char *buf)
55 {
56 	struct gsc_hwmon_data *hwmon = dev_get_drvdata(dev);
57 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
58 	u8 reg = hwmon->pdata->fan_base + (2 * attr->index);
59 	u8 regs[2];
60 	int ret;
61 
62 	ret = regmap_bulk_read(hwmon->regmap, reg, regs, 2);
63 	if (ret)
64 		return ret;
65 
66 	ret = regs[0] | regs[1] << 8;
67 	return sprintf(buf, "%d\n", ret * 10);
68 }
69 
70 static ssize_t pwm_auto_point_temp_store(struct device *dev,
71 					 struct device_attribute *devattr,
72 					 const char *buf, size_t count)
73 {
74 	struct gsc_hwmon_data *hwmon = dev_get_drvdata(dev);
75 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
76 	u8 reg = hwmon->pdata->fan_base + (2 * attr->index);
77 	u8 regs[2];
78 	long temp;
79 	int err;
80 
81 	if (kstrtol(buf, 10, &temp))
82 		return -EINVAL;
83 
84 	temp = clamp_val(temp, 0, 100000);
85 	temp = DIV_ROUND_CLOSEST(temp, 100);
86 
87 	regs[0] = temp & 0xff;
88 	regs[1] = (temp >> 8) & 0xff;
89 	err = regmap_bulk_write(hwmon->regmap, reg, regs, 2);
90 	if (err)
91 		return err;
92 
93 	return count;
94 }
95 
96 static ssize_t pwm_auto_point_pwm_show(struct device *dev,
97 				       struct device_attribute *devattr,
98 				       char *buf)
99 {
100 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
101 
102 	return sprintf(buf, "%d\n", 255 * (50 + (attr->index * 10)));
103 }
104 
105 static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point1_pwm, pwm_auto_point_pwm, 0);
106 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point1_temp, pwm_auto_point_temp, 0);
107 
108 static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point2_pwm, pwm_auto_point_pwm, 1);
109 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point2_temp, pwm_auto_point_temp, 1);
110 
111 static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point3_pwm, pwm_auto_point_pwm, 2);
112 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point3_temp, pwm_auto_point_temp, 2);
113 
114 static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point4_pwm, pwm_auto_point_pwm, 3);
115 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point4_temp, pwm_auto_point_temp, 3);
116 
117 static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point5_pwm, pwm_auto_point_pwm, 4);
118 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point5_temp, pwm_auto_point_temp, 4);
119 
120 static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point6_pwm, pwm_auto_point_pwm, 5);
121 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point6_temp, pwm_auto_point_temp, 5);
122 
123 static struct attribute *gsc_hwmon_attributes[] = {
124 	&sensor_dev_attr_pwm1_auto_point1_pwm.dev_attr.attr,
125 	&sensor_dev_attr_pwm1_auto_point1_temp.dev_attr.attr,
126 	&sensor_dev_attr_pwm1_auto_point2_pwm.dev_attr.attr,
127 	&sensor_dev_attr_pwm1_auto_point2_temp.dev_attr.attr,
128 	&sensor_dev_attr_pwm1_auto_point3_pwm.dev_attr.attr,
129 	&sensor_dev_attr_pwm1_auto_point3_temp.dev_attr.attr,
130 	&sensor_dev_attr_pwm1_auto_point4_pwm.dev_attr.attr,
131 	&sensor_dev_attr_pwm1_auto_point4_temp.dev_attr.attr,
132 	&sensor_dev_attr_pwm1_auto_point5_pwm.dev_attr.attr,
133 	&sensor_dev_attr_pwm1_auto_point5_temp.dev_attr.attr,
134 	&sensor_dev_attr_pwm1_auto_point6_pwm.dev_attr.attr,
135 	&sensor_dev_attr_pwm1_auto_point6_temp.dev_attr.attr,
136 	NULL
137 };
138 
139 static const struct attribute_group gsc_hwmon_group = {
140 	.attrs = gsc_hwmon_attributes,
141 };
142 __ATTRIBUTE_GROUPS(gsc_hwmon);
143 
144 static int
145 gsc_hwmon_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
146 	       int channel, long *val)
147 {
148 	struct gsc_hwmon_data *hwmon = dev_get_drvdata(dev);
149 	const struct gsc_hwmon_channel *ch;
150 	int sz, ret;
151 	long tmp;
152 	u8 buf[3];
153 
154 	switch (type) {
155 	case hwmon_in:
156 		ch = hwmon->in_ch[channel];
157 		break;
158 	case hwmon_temp:
159 		ch = hwmon->temp_ch[channel];
160 		break;
161 	case hwmon_fan:
162 		ch = hwmon->fan_ch[channel];
163 		break;
164 	default:
165 		return -EOPNOTSUPP;
166 	}
167 
168 	sz = (ch->mode == mode_voltage_24bit) ? 3 : 2;
169 	ret = regmap_bulk_read(hwmon->regmap, ch->reg, buf, sz);
170 	if (ret)
171 		return ret;
172 
173 	tmp = 0;
174 	while (sz-- > 0)
175 		tmp |= (buf[sz] << (8 * sz));
176 
177 	switch (ch->mode) {
178 	case mode_temperature:
179 		if (tmp > 0x8000)
180 			tmp -= 0xffff;
181 		tmp *= 100; /* convert to millidegrees celsius */
182 		break;
183 	case mode_voltage_raw:
184 		tmp = clamp_val(tmp, 0, BIT(GSC_HWMON_RESOLUTION));
185 		/* scale based on ref voltage and ADC resolution */
186 		tmp *= GSC_HWMON_VREF;
187 		tmp >>= GSC_HWMON_RESOLUTION;
188 		/* scale based on optional voltage divider */
189 		if (ch->vdiv[0] && ch->vdiv[1]) {
190 			tmp *= (ch->vdiv[0] + ch->vdiv[1]);
191 			tmp /= ch->vdiv[1];
192 		}
193 		/* adjust by uV offset */
194 		tmp += ch->mvoffset;
195 		break;
196 	case mode_fan:
197 		tmp *= 30; /* convert to revolutions per minute */
198 		break;
199 	case mode_voltage_24bit:
200 	case mode_voltage_16bit:
201 		/* no adjustment needed */
202 		break;
203 	}
204 
205 	*val = tmp;
206 
207 	return 0;
208 }
209 
210 static int
211 gsc_hwmon_read_string(struct device *dev, enum hwmon_sensor_types type,
212 		      u32 attr, int channel, const char **buf)
213 {
214 	struct gsc_hwmon_data *hwmon = dev_get_drvdata(dev);
215 
216 	switch (type) {
217 	case hwmon_in:
218 		*buf = hwmon->in_ch[channel]->name;
219 		break;
220 	case hwmon_temp:
221 		*buf = hwmon->temp_ch[channel]->name;
222 		break;
223 	case hwmon_fan:
224 		*buf = hwmon->fan_ch[channel]->name;
225 		break;
226 	default:
227 		return -ENOTSUPP;
228 	}
229 
230 	return 0;
231 }
232 
233 static const struct hwmon_ops gsc_hwmon_ops = {
234 	.visible = 0444,
235 	.read = gsc_hwmon_read,
236 	.read_string = gsc_hwmon_read_string,
237 };
238 
239 static struct gsc_hwmon_platform_data *
240 gsc_hwmon_get_devtree_pdata(struct device *dev)
241 {
242 	struct gsc_hwmon_platform_data *pdata;
243 	struct gsc_hwmon_channel *ch;
244 	struct device_node *fan;
245 	int nchannels;
246 
247 	nchannels = device_get_child_node_count(dev);
248 	if (nchannels == 0)
249 		return ERR_PTR(-ENODEV);
250 
251 	pdata = devm_kzalloc(dev, struct_size(pdata, channels, nchannels),
252 			     GFP_KERNEL);
253 	if (!pdata)
254 		return ERR_PTR(-ENOMEM);
255 	pdata->nchannels = nchannels;
256 
257 	/* fan controller base address */
258 	of_node_get(dev->parent->of_node);
259 	fan = of_find_compatible_node(dev->parent->of_node, NULL, "gw,gsc-fan");
260 	if (fan && of_property_read_u32(fan, "reg", &pdata->fan_base)) {
261 		of_node_put(fan);
262 		dev_err(dev, "fan node without base\n");
263 		return ERR_PTR(-EINVAL);
264 	}
265 
266 	of_node_put(fan);
267 
268 	ch = pdata->channels;
269 	/* allocate structures for channels and count instances of each type */
270 	device_for_each_child_node_scoped(dev, child) {
271 		if (fwnode_property_read_string(child, "label", &ch->name)) {
272 			dev_err(dev, "channel without label\n");
273 			return ERR_PTR(-EINVAL);
274 		}
275 		if (fwnode_property_read_u32(child, "reg", &ch->reg)) {
276 			dev_err(dev, "channel without reg\n");
277 			return ERR_PTR(-EINVAL);
278 		}
279 		if (fwnode_property_read_u32(child, "gw,mode", &ch->mode)) {
280 			dev_err(dev, "channel without mode\n");
281 			return ERR_PTR(-EINVAL);
282 		}
283 		if (ch->mode > mode_max) {
284 			dev_err(dev, "invalid channel mode\n");
285 			return ERR_PTR(-EINVAL);
286 		}
287 
288 		if (!fwnode_property_read_u32(child,
289 					      "gw,voltage-offset-microvolt",
290 					      &ch->mvoffset))
291 			ch->mvoffset /= 1000;
292 		fwnode_property_read_u32_array(child,
293 					       "gw,voltage-divider-ohms",
294 					       ch->vdiv, ARRAY_SIZE(ch->vdiv));
295 		ch++;
296 	}
297 
298 	return pdata;
299 }
300 
301 static int gsc_hwmon_probe(struct platform_device *pdev)
302 {
303 	struct gsc_dev *gsc = dev_get_drvdata(pdev->dev.parent);
304 	struct device *dev = &pdev->dev;
305 	struct device *hwmon_dev;
306 	struct gsc_hwmon_platform_data *pdata = dev_get_platdata(dev);
307 	struct gsc_hwmon_data *hwmon;
308 	const struct attribute_group **groups;
309 	int i, i_in, i_temp, i_fan;
310 
311 	if (!pdata) {
312 		pdata = gsc_hwmon_get_devtree_pdata(dev);
313 		if (IS_ERR(pdata))
314 			return PTR_ERR(pdata);
315 	}
316 
317 	hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL);
318 	if (!hwmon)
319 		return -ENOMEM;
320 	hwmon->gsc = gsc;
321 	hwmon->pdata = pdata;
322 
323 	hwmon->regmap = devm_regmap_init(dev, &gsc_hwmon_regmap_bus,
324 					 gsc->i2c_hwmon,
325 					 &gsc_hwmon_regmap_config);
326 	if (IS_ERR(hwmon->regmap))
327 		return PTR_ERR(hwmon->regmap);
328 
329 	for (i = 0, i_in = 0, i_temp = 0, i_fan = 0; i < hwmon->pdata->nchannels; i++) {
330 		const struct gsc_hwmon_channel *ch = &pdata->channels[i];
331 
332 		switch (ch->mode) {
333 		case mode_temperature:
334 			if (i_temp == GSC_HWMON_MAX_TEMP_CH) {
335 				dev_err(gsc->dev, "too many temp channels\n");
336 				return -EINVAL;
337 			}
338 			hwmon->temp_ch[i_temp] = ch;
339 			hwmon->temp_config[i_temp] = HWMON_T_INPUT |
340 						     HWMON_T_LABEL;
341 			i_temp++;
342 			break;
343 		case mode_fan:
344 			if (i_fan == GSC_HWMON_MAX_FAN_CH) {
345 				dev_err(gsc->dev, "too many fan channels\n");
346 				return -EINVAL;
347 			}
348 			hwmon->fan_ch[i_fan] = ch;
349 			hwmon->fan_config[i_fan] = HWMON_F_INPUT |
350 						   HWMON_F_LABEL;
351 			i_fan++;
352 			break;
353 		case mode_voltage_24bit:
354 		case mode_voltage_16bit:
355 		case mode_voltage_raw:
356 			if (i_in == GSC_HWMON_MAX_IN_CH) {
357 				dev_err(gsc->dev, "too many input channels\n");
358 				return -EINVAL;
359 			}
360 			hwmon->in_ch[i_in] = ch;
361 			hwmon->in_config[i_in] =
362 				HWMON_I_INPUT | HWMON_I_LABEL;
363 			i_in++;
364 			break;
365 		default:
366 			dev_err(gsc->dev, "invalid mode: %d\n", ch->mode);
367 			return -EINVAL;
368 		}
369 	}
370 
371 	/* setup config structures */
372 	hwmon->chip.ops = &gsc_hwmon_ops;
373 	hwmon->chip.info = hwmon->info;
374 	hwmon->info[0] = &hwmon->temp_info;
375 	hwmon->info[1] = &hwmon->in_info;
376 	hwmon->info[2] = &hwmon->fan_info;
377 	hwmon->temp_info.type = hwmon_temp;
378 	hwmon->temp_info.config = hwmon->temp_config;
379 	hwmon->in_info.type = hwmon_in;
380 	hwmon->in_info.config = hwmon->in_config;
381 	hwmon->fan_info.type = hwmon_fan;
382 	hwmon->fan_info.config = hwmon->fan_config;
383 
384 	groups = pdata->fan_base ? gsc_hwmon_groups : NULL;
385 	hwmon_dev = devm_hwmon_device_register_with_info(dev,
386 							 KBUILD_MODNAME, hwmon,
387 							 &hwmon->chip, groups);
388 	return PTR_ERR_OR_ZERO(hwmon_dev);
389 }
390 
391 static const struct of_device_id gsc_hwmon_of_match[] = {
392 	{ .compatible = "gw,gsc-adc", },
393 	{}
394 };
395 MODULE_DEVICE_TABLE(of, gsc_hwmon_of_match);
396 
397 static struct platform_driver gsc_hwmon_driver = {
398 	.driver = {
399 		.name = "gsc-hwmon",
400 		.of_match_table = gsc_hwmon_of_match,
401 	},
402 	.probe = gsc_hwmon_probe,
403 };
404 
405 module_platform_driver(gsc_hwmon_driver);
406 
407 MODULE_AUTHOR("Tim Harvey <tharvey@gateworks.com>");
408 MODULE_DESCRIPTION("GSC hardware monitor driver");
409 MODULE_LICENSE("GPL v2");
410