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
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 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, struct_size(pdata, channels, nchannels),
261 GFP_KERNEL);
262 if (!pdata)
263 return ERR_PTR(-ENOMEM);
264 pdata->nchannels = nchannels;
265
266 /* fan controller base address */
267 of_node_get(dev->parent->of_node);
268 fan = of_find_compatible_node(dev->parent->of_node, NULL, "gw,gsc-fan");
269 if (fan && of_property_read_u32(fan, "reg", &pdata->fan_base)) {
270 of_node_put(fan);
271 dev_err(dev, "fan node without base\n");
272 return ERR_PTR(-EINVAL);
273 }
274
275 of_node_put(fan);
276
277 ch = pdata->channels;
278 /* allocate structures for channels and count instances of each type */
279 device_for_each_child_node(dev, child) {
280 if (fwnode_property_read_string(child, "label", &ch->name)) {
281 dev_err(dev, "channel without label\n");
282 fwnode_handle_put(child);
283 return ERR_PTR(-EINVAL);
284 }
285 if (fwnode_property_read_u32(child, "reg", &ch->reg)) {
286 dev_err(dev, "channel without reg\n");
287 fwnode_handle_put(child);
288 return ERR_PTR(-EINVAL);
289 }
290 if (fwnode_property_read_u32(child, "gw,mode", &ch->mode)) {
291 dev_err(dev, "channel without mode\n");
292 fwnode_handle_put(child);
293 return ERR_PTR(-EINVAL);
294 }
295 if (ch->mode > mode_max) {
296 dev_err(dev, "invalid channel mode\n");
297 fwnode_handle_put(child);
298 return ERR_PTR(-EINVAL);
299 }
300
301 if (!fwnode_property_read_u32(child,
302 "gw,voltage-offset-microvolt",
303 &ch->mvoffset))
304 ch->mvoffset /= 1000;
305 fwnode_property_read_u32_array(child,
306 "gw,voltage-divider-ohms",
307 ch->vdiv, ARRAY_SIZE(ch->vdiv));
308 ch++;
309 }
310
311 return pdata;
312 }
313
gsc_hwmon_probe(struct platform_device * pdev)314 static int gsc_hwmon_probe(struct platform_device *pdev)
315 {
316 struct gsc_dev *gsc = dev_get_drvdata(pdev->dev.parent);
317 struct device *dev = &pdev->dev;
318 struct device *hwmon_dev;
319 struct gsc_hwmon_platform_data *pdata = dev_get_platdata(dev);
320 struct gsc_hwmon_data *hwmon;
321 const struct attribute_group **groups;
322 int i, i_in, i_temp, i_fan;
323
324 if (!pdata) {
325 pdata = gsc_hwmon_get_devtree_pdata(dev);
326 if (IS_ERR(pdata))
327 return PTR_ERR(pdata);
328 }
329
330 hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL);
331 if (!hwmon)
332 return -ENOMEM;
333 hwmon->gsc = gsc;
334 hwmon->pdata = pdata;
335
336 hwmon->regmap = devm_regmap_init(dev, &gsc_hwmon_regmap_bus,
337 gsc->i2c_hwmon,
338 &gsc_hwmon_regmap_config);
339 if (IS_ERR(hwmon->regmap))
340 return PTR_ERR(hwmon->regmap);
341
342 for (i = 0, i_in = 0, i_temp = 0, i_fan = 0; i < hwmon->pdata->nchannels; i++) {
343 const struct gsc_hwmon_channel *ch = &pdata->channels[i];
344
345 switch (ch->mode) {
346 case mode_temperature:
347 if (i_temp == GSC_HWMON_MAX_TEMP_CH) {
348 dev_err(gsc->dev, "too many temp channels\n");
349 return -EINVAL;
350 }
351 hwmon->temp_ch[i_temp] = ch;
352 hwmon->temp_config[i_temp] = HWMON_T_INPUT |
353 HWMON_T_LABEL;
354 i_temp++;
355 break;
356 case mode_fan:
357 if (i_fan == GSC_HWMON_MAX_FAN_CH) {
358 dev_err(gsc->dev, "too many fan channels\n");
359 return -EINVAL;
360 }
361 hwmon->fan_ch[i_fan] = ch;
362 hwmon->fan_config[i_fan] = HWMON_F_INPUT |
363 HWMON_F_LABEL;
364 i_fan++;
365 break;
366 case mode_voltage_24bit:
367 case mode_voltage_16bit:
368 case mode_voltage_raw:
369 if (i_in == GSC_HWMON_MAX_IN_CH) {
370 dev_err(gsc->dev, "too many input channels\n");
371 return -EINVAL;
372 }
373 hwmon->in_ch[i_in] = ch;
374 hwmon->in_config[i_in] =
375 HWMON_I_INPUT | HWMON_I_LABEL;
376 i_in++;
377 break;
378 default:
379 dev_err(gsc->dev, "invalid mode: %d\n", ch->mode);
380 return -EINVAL;
381 }
382 }
383
384 /* setup config structures */
385 hwmon->chip.ops = &gsc_hwmon_ops;
386 hwmon->chip.info = hwmon->info;
387 hwmon->info[0] = &hwmon->temp_info;
388 hwmon->info[1] = &hwmon->in_info;
389 hwmon->info[2] = &hwmon->fan_info;
390 hwmon->temp_info.type = hwmon_temp;
391 hwmon->temp_info.config = hwmon->temp_config;
392 hwmon->in_info.type = hwmon_in;
393 hwmon->in_info.config = hwmon->in_config;
394 hwmon->fan_info.type = hwmon_fan;
395 hwmon->fan_info.config = hwmon->fan_config;
396
397 groups = pdata->fan_base ? gsc_hwmon_groups : NULL;
398 hwmon_dev = devm_hwmon_device_register_with_info(dev,
399 KBUILD_MODNAME, hwmon,
400 &hwmon->chip, groups);
401 return PTR_ERR_OR_ZERO(hwmon_dev);
402 }
403
404 static const struct of_device_id gsc_hwmon_of_match[] = {
405 { .compatible = "gw,gsc-adc", },
406 {}
407 };
408
409 static struct platform_driver gsc_hwmon_driver = {
410 .driver = {
411 .name = "gsc-hwmon",
412 .of_match_table = gsc_hwmon_of_match,
413 },
414 .probe = gsc_hwmon_probe,
415 };
416
417 module_platform_driver(gsc_hwmon_driver);
418
419 MODULE_AUTHOR("Tim Harvey <tharvey@gateworks.com>");
420 MODULE_DESCRIPTION("GSC hardware monitor driver");
421 MODULE_LICENSE("GPL v2");
422
