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 .cache_type = REGCACHE_NONE,
51 };
52
pwm_auto_point_temp_show(struct device * dev,struct device_attribute * devattr,char * buf)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
pwm_auto_point_temp_store(struct device * dev,struct device_attribute * devattr,const char * buf,size_t count)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, 100000);
86 temp = DIV_ROUND_CLOSEST(temp, 100);
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
pwm_auto_point_pwm_show(struct device * dev,struct device_attribute * devattr,char * buf)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)));
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
gsc_hwmon_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)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
gsc_hwmon_read_string(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,const char ** buf)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
gsc_hwmon_is_visible(const void * _data,enum hwmon_sensor_types type,u32 attr,int ch)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 *
gsc_hwmon_get_devtree_pdata(struct device * dev)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 device_node *fan;
253 int nchannels;
254
255 nchannels = device_get_child_node_count(dev);
256 if (nchannels == 0)
257 return ERR_PTR(-ENODEV);
258
259 pdata = devm_kzalloc(dev, struct_size(pdata, channels, nchannels),
260 GFP_KERNEL);
261 if (!pdata)
262 return ERR_PTR(-ENOMEM);
263 pdata->nchannels = nchannels;
264
265 /* fan controller base address */
266 of_node_get(dev->parent->of_node);
267 fan = of_find_compatible_node(dev->parent->of_node, NULL, "gw,gsc-fan");
268 if (fan && of_property_read_u32(fan, "reg", &pdata->fan_base)) {
269 of_node_put(fan);
270 dev_err(dev, "fan node without base\n");
271 return ERR_PTR(-EINVAL);
272 }
273
274 of_node_put(fan);
275
276 ch = pdata->channels;
277 /* allocate structures for channels and count instances of each type */
278 device_for_each_child_node_scoped(dev, child) {
279 if (fwnode_property_read_string(child, "label", &ch->name)) {
280 dev_err(dev, "channel without label\n");
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 return ERR_PTR(-EINVAL);
286 }
287 if (fwnode_property_read_u32(child, "gw,mode", &ch->mode)) {
288 dev_err(dev, "channel without mode\n");
289 return ERR_PTR(-EINVAL);
290 }
291 if (ch->mode > mode_max) {
292 dev_err(dev, "invalid channel mode\n");
293 return ERR_PTR(-EINVAL);
294 }
295
296 if (!fwnode_property_read_u32(child,
297 "gw,voltage-offset-microvolt",
298 &ch->mvoffset))
299 ch->mvoffset /= 1000;
300 fwnode_property_read_u32_array(child,
301 "gw,voltage-divider-ohms",
302 ch->vdiv, ARRAY_SIZE(ch->vdiv));
303 ch++;
304 }
305
306 return pdata;
307 }
308
gsc_hwmon_probe(struct platform_device * pdev)309 static int gsc_hwmon_probe(struct platform_device *pdev)
310 {
311 struct gsc_dev *gsc = dev_get_drvdata(pdev->dev.parent);
312 struct device *dev = &pdev->dev;
313 struct device *hwmon_dev;
314 struct gsc_hwmon_platform_data *pdata = dev_get_platdata(dev);
315 struct gsc_hwmon_data *hwmon;
316 const struct attribute_group **groups;
317 int i, i_in, i_temp, i_fan;
318
319 if (!pdata) {
320 pdata = gsc_hwmon_get_devtree_pdata(dev);
321 if (IS_ERR(pdata))
322 return PTR_ERR(pdata);
323 }
324
325 hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL);
326 if (!hwmon)
327 return -ENOMEM;
328 hwmon->gsc = gsc;
329 hwmon->pdata = pdata;
330
331 hwmon->regmap = devm_regmap_init(dev, &gsc_hwmon_regmap_bus,
332 gsc->i2c_hwmon,
333 &gsc_hwmon_regmap_config);
334 if (IS_ERR(hwmon->regmap))
335 return PTR_ERR(hwmon->regmap);
336
337 for (i = 0, i_in = 0, i_temp = 0, i_fan = 0; i < hwmon->pdata->nchannels; i++) {
338 const struct gsc_hwmon_channel *ch = &pdata->channels[i];
339
340 switch (ch->mode) {
341 case mode_temperature:
342 if (i_temp == GSC_HWMON_MAX_TEMP_CH) {
343 dev_err(gsc->dev, "too many temp channels\n");
344 return -EINVAL;
345 }
346 hwmon->temp_ch[i_temp] = ch;
347 hwmon->temp_config[i_temp] = HWMON_T_INPUT |
348 HWMON_T_LABEL;
349 i_temp++;
350 break;
351 case mode_fan:
352 if (i_fan == GSC_HWMON_MAX_FAN_CH) {
353 dev_err(gsc->dev, "too many fan channels\n");
354 return -EINVAL;
355 }
356 hwmon->fan_ch[i_fan] = ch;
357 hwmon->fan_config[i_fan] = HWMON_F_INPUT |
358 HWMON_F_LABEL;
359 i_fan++;
360 break;
361 case mode_voltage_24bit:
362 case mode_voltage_16bit:
363 case mode_voltage_raw:
364 if (i_in == GSC_HWMON_MAX_IN_CH) {
365 dev_err(gsc->dev, "too many input channels\n");
366 return -EINVAL;
367 }
368 hwmon->in_ch[i_in] = ch;
369 hwmon->in_config[i_in] =
370 HWMON_I_INPUT | HWMON_I_LABEL;
371 i_in++;
372 break;
373 default:
374 dev_err(gsc->dev, "invalid mode: %d\n", ch->mode);
375 return -EINVAL;
376 }
377 }
378
379 /* setup config structures */
380 hwmon->chip.ops = &gsc_hwmon_ops;
381 hwmon->chip.info = hwmon->info;
382 hwmon->info[0] = &hwmon->temp_info;
383 hwmon->info[1] = &hwmon->in_info;
384 hwmon->info[2] = &hwmon->fan_info;
385 hwmon->temp_info.type = hwmon_temp;
386 hwmon->temp_info.config = hwmon->temp_config;
387 hwmon->in_info.type = hwmon_in;
388 hwmon->in_info.config = hwmon->in_config;
389 hwmon->fan_info.type = hwmon_fan;
390 hwmon->fan_info.config = hwmon->fan_config;
391
392 groups = pdata->fan_base ? gsc_hwmon_groups : NULL;
393 hwmon_dev = devm_hwmon_device_register_with_info(dev,
394 KBUILD_MODNAME, hwmon,
395 &hwmon->chip, groups);
396 return PTR_ERR_OR_ZERO(hwmon_dev);
397 }
398
399 static const struct of_device_id gsc_hwmon_of_match[] = {
400 { .compatible = "gw,gsc-adc", },
401 {}
402 };
403 MODULE_DEVICE_TABLE(of, gsc_hwmon_of_match);
404
405 static struct platform_driver gsc_hwmon_driver = {
406 .driver = {
407 .name = "gsc-hwmon",
408 .of_match_table = gsc_hwmon_of_match,
409 },
410 .probe = gsc_hwmon_probe,
411 };
412
413 module_platform_driver(gsc_hwmon_driver);
414
415 MODULE_AUTHOR("Tim Harvey <tharvey@gateworks.com>");
416 MODULE_DESCRIPTION("GSC hardware monitor driver");
417 MODULE_LICENSE("GPL v2");
418