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
pwm_auto_point_temp_show(struct device * dev,struct device_attribute * devattr,char * buf)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
pwm_auto_point_temp_store(struct device * dev,struct device_attribute * devattr,const char * buf,size_t count)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
pwm_auto_point_pwm_show(struct device * dev,struct device_attribute * devattr,char * buf)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
gsc_hwmon_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)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
gsc_hwmon_read_string(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,const char ** buf)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 *
gsc_hwmon_get_devtree_pdata(struct device * dev)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
gsc_hwmon_probe(struct platform_device * pdev)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