max1619.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * max1619.c - Part of lm_sensors, Linux kernel modules for hardware
  4 *             monitoring
  5 * Copyright (C) 2003-2004 Oleksij Rempel <bug-track@fisher-privat.net>
  6 *                         Jean Delvare <jdelvare@suse.de>
  7 *
  8 * Based on the lm90 driver. The MAX1619 is a sensor chip made by Maxim.
  9 * It reports up to two temperatures (its own plus up to
 10 * one external one). Complete datasheet can be
 11 * obtained from Maxim's website at:
 12 *   http://pdfserv.maxim-ic.com/en/ds/MAX1619.pdf
 13 */
 14
 15#include <linux/err.h>
 16#include <linux/hwmon.h>
 17#include <linux/i2c.h>
 18#include <linux/init.h>
 19#include <linux/module.h>
 20#include <linux/regmap.h>
 21#include <linux/util_macros.h>
 22
 23static const unsigned short normal_i2c[] = {
 24	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
 25
 26#define MAX1619_REG_LOCAL_TEMP		0x00
 27#define MAX1619_REG_REMOTE_TEMP		0x01
 28#define MAX1619_REG_STATUS		0x02
 29#define MAX1619_REG_CONFIG		0x03
 30#define MAX1619_REG_CONVRATE		0x04
 31#define MAX1619_REG_REMOTE_HIGH		0x07
 32#define MAX1619_REG_REMOTE_LOW		0x08
 33#define MAX1619_REG_REMOTE_CRIT		0x10
 34#define MAX1619_REG_REMOTE_CRIT_HYST	0x11
 35#define MAX1619_REG_MAN_ID		0xFE
 36#define MAX1619_REG_CHIP_ID		0xFF
 37
 38static int get_alarms(struct regmap *regmap)
 39{
 40	static u32 regs[2] = { MAX1619_REG_STATUS, MAX1619_REG_CONFIG };
 41	u8 regdata[2];
 42	int ret;
 43
 44	ret = regmap_multi_reg_read(regmap, regs, regdata, 2);
 45	if (ret)
 46		return ret;
 47
 48	/* OVERT status bit may be reversed */
 49	if (!(regdata[1] & 0x20))
 50		regdata[0] ^= 0x02;
 51
 52	return regdata[0] & 0x1e;
 53}
 54
 55static int max1619_temp_read(struct regmap *regmap, u32 attr, int channel, long *val)
 56{
 57	int reg = -1, alarm_bit = 0;
 58	u32 temp;
 59	int ret;
 60
 61	switch (attr) {
 62	case hwmon_temp_input:
 63		reg = channel ? MAX1619_REG_REMOTE_TEMP : MAX1619_REG_LOCAL_TEMP;
 64		break;
 65	case hwmon_temp_min:
 66		reg = MAX1619_REG_REMOTE_LOW;
 67		break;
 68	case hwmon_temp_max:
 69		reg = MAX1619_REG_REMOTE_HIGH;
 70		break;
 71	case hwmon_temp_crit:
 72		reg = MAX1619_REG_REMOTE_CRIT;
 73		break;
 74	case hwmon_temp_crit_hyst:
 75		reg = MAX1619_REG_REMOTE_CRIT_HYST;
 76		break;
 77	case hwmon_temp_min_alarm:
 78		alarm_bit = 3;
 79		break;
 80	case hwmon_temp_max_alarm:
 81		alarm_bit = 4;
 82		break;
 83	case hwmon_temp_crit_alarm:
 84		alarm_bit = 1;
 85		break;
 86	case hwmon_temp_fault:
 87		alarm_bit = 2;
 88		break;
 89	default:
 90		return -EOPNOTSUPP;
 91	}
 92	if (reg >= 0) {
 93		ret = regmap_read(regmap, reg, &temp);
 94		if (ret < 0)
 95			return ret;
 96		*val = sign_extend32(temp, 7) * 1000;
 97	} else {
 98		ret = get_alarms(regmap);
 99		if (ret < 0)
100			return ret;
101		*val = !!(ret & BIT(alarm_bit));
102	}
103	return 0;
104}
105
106static u16 update_intervals[] = { 16000, 8000, 4000, 2000, 1000, 500, 250, 125 };
107
108static int max1619_chip_read(struct regmap *regmap, u32 attr, long *val)
109{
110	int alarms, ret;
111	u32 regval;
112
113	switch (attr) {
114	case hwmon_chip_update_interval:
115		ret = regmap_read(regmap, MAX1619_REG_CONVRATE, &regval);
116		if (ret < 0)
117			return ret;
118		*val = update_intervals[regval & 7];
119		break;
120	case hwmon_chip_alarms:
121		alarms = get_alarms(regmap);
122		if (alarms < 0)
123			return alarms;
124		*val = alarms;
125		break;
126	default:
127		return -EOPNOTSUPP;
128	}
129	return 0;
130}
131
132static int max1619_read(struct device *dev, enum hwmon_sensor_types type,
133			u32 attr, int channel, long *val)
134{
135	struct regmap *regmap = dev_get_drvdata(dev);
136
137	switch (type) {
138	case hwmon_chip:
139		return max1619_chip_read(regmap, attr, val);
140	case hwmon_temp:
141		return max1619_temp_read(regmap, attr, channel, val);
142	default:
143		return -EOPNOTSUPP;
144	}
145}
146
147static int max1619_chip_write(struct regmap *regmap, u32 attr, long val)
148{
149	switch (attr) {
150	case hwmon_chip_update_interval:
151		val = find_closest_descending(val, update_intervals, ARRAY_SIZE(update_intervals));
152		return regmap_write(regmap, MAX1619_REG_CONVRATE, val);
153	default:
154		return -EOPNOTSUPP;
155	}
156}
157
158static int max1619_temp_write(struct regmap *regmap,
159			      u32 attr, int channel, long val)
160{
161	int reg;
162
163	switch (attr) {
164	case hwmon_temp_min:
165		reg = MAX1619_REG_REMOTE_LOW;
166		break;
167	case hwmon_temp_max:
168		reg = MAX1619_REG_REMOTE_HIGH;
169		break;
170	case hwmon_temp_crit:
171		reg = MAX1619_REG_REMOTE_CRIT;
172		break;
173	case hwmon_temp_crit_hyst:
174		reg = MAX1619_REG_REMOTE_CRIT_HYST;
175		break;
176	default:
177		return -EOPNOTSUPP;
178	}
179	val = DIV_ROUND_CLOSEST(clamp_val(val, -128000, 127000), 1000);
180	return regmap_write(regmap, reg, val);
181}
182
183static int max1619_write(struct device *dev, enum hwmon_sensor_types type,
184			 u32 attr, int channel, long val)
185{
186	struct regmap *regmap = dev_get_drvdata(dev);
187
188	switch (type) {
189	case hwmon_chip:
190		return max1619_chip_write(regmap, attr, val);
191	case hwmon_temp:
192		return max1619_temp_write(regmap, attr, channel, val);
193	default:
194		return -EOPNOTSUPP;
195	}
196}
197
198static umode_t max1619_is_visible(const void *_data, enum hwmon_sensor_types type,
199				  u32 attr, int channel)
200{
201	switch (type) {
202	case hwmon_chip:
203		switch (attr) {
204		case hwmon_chip_update_interval:
205			return 0644;
206		case hwmon_chip_alarms:
207			return 0444;
208		default:
209			break;
210		}
211		break;
212	case hwmon_temp:
213		switch (attr) {
214		case hwmon_temp_input:
215			return 0444;
216		case hwmon_temp_min:
217		case hwmon_temp_max:
218		case hwmon_temp_crit:
219		case hwmon_temp_crit_hyst:
220			return 0644;
221		case hwmon_temp_min_alarm:
222		case hwmon_temp_max_alarm:
223		case hwmon_temp_crit_alarm:
224		case hwmon_temp_fault:
225			return 0444;
226		default:
227			break;
228		}
229		break;
230	default:
231		break;
232	}
233	return 0;
234}
235
236static const struct hwmon_channel_info * const max1619_info[] = {
237	HWMON_CHANNEL_INFO(chip, HWMON_C_ALARMS | HWMON_C_UPDATE_INTERVAL),
238	HWMON_CHANNEL_INFO(temp,
239			   HWMON_T_INPUT,
240			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
241			   HWMON_T_CRIT | HWMON_T_CRIT_HYST |
242			   HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
243			   HWMON_T_CRIT_ALARM | HWMON_T_FAULT),
244	NULL
245};
246
247static const struct hwmon_ops max1619_hwmon_ops = {
248	.is_visible = max1619_is_visible,
249	.read = max1619_read,
250	.write = max1619_write,
251};
252
253static const struct hwmon_chip_info max1619_chip_info = {
254	.ops = &max1619_hwmon_ops,
255	.info = max1619_info,
256};
257
258/* Return 0 if detection is successful, -ENODEV otherwise */
259static int max1619_detect(struct i2c_client *client,
260			  struct i2c_board_info *info)
261{
262	struct i2c_adapter *adapter = client->adapter;
263	int regval;
264
265	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
266		return -ENODEV;
267
268	regval = i2c_smbus_read_byte_data(client, MAX1619_REG_CONFIG);
269	if (regval < 0 || (regval & 0x03))
270		return -ENODEV;
271	regval = i2c_smbus_read_byte_data(client, MAX1619_REG_CONVRATE);
272	if (regval < 0 || regval > 0x07)
273		return -ENODEV;
274	regval = i2c_smbus_read_byte_data(client, MAX1619_REG_STATUS);
275	if (regval < 0 || (regval & 0x61))
276		return -ENODEV;
277
278	regval = i2c_smbus_read_byte_data(client, MAX1619_REG_MAN_ID);
279	if (regval != 0x4d)
280		return -ENODEV;
281	regval = i2c_smbus_read_byte_data(client, MAX1619_REG_CHIP_ID);
282	if (regval != 0x04)
283		return -ENODEV;
284
285	strscpy(info->type, "max1619", I2C_NAME_SIZE);
286
287	return 0;
288}
289
290static int max1619_init_chip(struct regmap *regmap)
291{
292	int ret;
293
294	ret = regmap_write(regmap, MAX1619_REG_CONVRATE, 5);	/* 2 Hz */
295	if (ret)
296		return ret;
297
298	/* Start conversions */
299	return regmap_clear_bits(regmap, MAX1619_REG_CONFIG, 0x40);
300}
301
302/* regmap */
303
304static int max1619_reg_read(void *context, unsigned int reg, unsigned int *val)
305{
306	int ret;
307
308	ret = i2c_smbus_read_byte_data(context, reg);
309	if (ret < 0)
310		return ret;
311
312	*val = ret;
313	return 0;
314}
315
316static int max1619_reg_write(void *context, unsigned int reg, unsigned int val)
317{
318	int offset = reg < MAX1619_REG_REMOTE_CRIT ? 6 : 2;
319
320	return i2c_smbus_write_byte_data(context, reg + offset, val);
321}
322
323static bool max1619_regmap_is_volatile(struct device *dev, unsigned int reg)
324{
325	return reg <= MAX1619_REG_STATUS;
326}
327
328static bool max1619_regmap_is_writeable(struct device *dev, unsigned int reg)
329{
330	return reg > MAX1619_REG_STATUS && reg <= MAX1619_REG_REMOTE_CRIT_HYST;
331}
332
333static const struct regmap_config max1619_regmap_config = {
334	.reg_bits = 8,
335	.val_bits = 8,
336	.max_register = MAX1619_REG_REMOTE_CRIT_HYST,
337	.cache_type = REGCACHE_MAPLE,
338	.volatile_reg = max1619_regmap_is_volatile,
339	.writeable_reg = max1619_regmap_is_writeable,
340};
341
342static const struct regmap_bus max1619_regmap_bus = {
343	.reg_write = max1619_reg_write,
344	.reg_read = max1619_reg_read,
345};
346
347static int max1619_probe(struct i2c_client *client)
348{
349	struct device *dev = &client->dev;
350	struct device *hwmon_dev;
351	struct regmap *regmap;
352	int ret;
353
354	regmap = devm_regmap_init(dev, &max1619_regmap_bus, client,
355				  &max1619_regmap_config);
356	if (IS_ERR(regmap))
357		return PTR_ERR(regmap);
358
359	ret = max1619_init_chip(regmap);
360	if (ret)
361		return ret;
362
363	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
364							 regmap, &max1619_chip_info, NULL);
365	return PTR_ERR_OR_ZERO(hwmon_dev);
366}
367
368static const struct i2c_device_id max1619_id[] = {
369	{ "max1619" },
370	{ }
371};
372MODULE_DEVICE_TABLE(i2c, max1619_id);
373
374#ifdef CONFIG_OF
375static const struct of_device_id max1619_of_match[] = {
376	{ .compatible = "maxim,max1619", },
377	{},
378};
379
380MODULE_DEVICE_TABLE(of, max1619_of_match);
381#endif
382
383static struct i2c_driver max1619_driver = {
384	.class		= I2C_CLASS_HWMON,
385	.driver = {
386		.name	= "max1619",
387		.of_match_table = of_match_ptr(max1619_of_match),
388	},
389	.probe		= max1619_probe,
390	.id_table	= max1619_id,
391	.detect		= max1619_detect,
392	.address_list	= normal_i2c,
393};
394
395module_i2c_driver(max1619_driver);
396
397MODULE_AUTHOR("Oleksij Rempel <bug-track@fisher-privat.net>, Jean Delvare <jdelvare@suse.de>");
398MODULE_DESCRIPTION("MAX1619 sensor driver");
399MODULE_LICENSE("GPL");