xref: /openbmc/linux/drivers/hwmon/oxp-sensors.c (revision 2aa71b4b)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Platform driver for OneXPlayer, AOK ZOE, and Aya Neo Handhelds that expose
4  * fan reading and control via hwmon sysfs.
5  *
6  * Old OXP boards have the same DMI strings and they are told apart by
7  * the boot cpu vendor (Intel/AMD). Currently only AMD boards are
8  * supported but the code is made to be simple to add other handheld
9  * boards in the future.
10  * Fan control is provided via pwm interface in the range [0-255].
11  * Old AMD boards use [0-100] as range in the EC, the written value is
12  * scaled to accommodate for that. Newer boards like the mini PRO and
13  * AOK ZOE are not scaled but have the same EC layout.
14  *
15  * Copyright (C) 2022 Joaquín I. Aramendía <samsagax@gmail.com>
16  */
17 
18 #include <linux/acpi.h>
19 #include <linux/dmi.h>
20 #include <linux/hwmon.h>
21 #include <linux/init.h>
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/platform_device.h>
25 #include <linux/processor.h>
26 
27 /* Handle ACPI lock mechanism */
28 static u32 oxp_mutex;
29 
30 #define ACPI_LOCK_DELAY_MS	500
31 
32 static bool lock_global_acpi_lock(void)
33 {
34 	return ACPI_SUCCESS(acpi_acquire_global_lock(ACPI_LOCK_DELAY_MS, &oxp_mutex));
35 }
36 
37 static bool unlock_global_acpi_lock(void)
38 {
39 	return ACPI_SUCCESS(acpi_release_global_lock(oxp_mutex));
40 }
41 
42 enum oxp_board {
43 	aok_zoe_a1 = 1,
44 	aya_neo_2,
45 	aya_neo_air,
46 	aya_neo_air_pro,
47 	aya_neo_geek,
48 	oxp_mini_amd,
49 	oxp_mini_amd_a07,
50 	oxp_mini_amd_pro,
51 };
52 
53 static enum oxp_board board;
54 
55 /* Fan reading and PWM */
56 #define OXP_SENSOR_FAN_REG		0x76 /* Fan reading is 2 registers long */
57 #define OXP_SENSOR_PWM_ENABLE_REG	0x4A /* PWM enable is 1 register long */
58 #define OXP_SENSOR_PWM_REG		0x4B /* PWM reading is 1 register long */
59 
60 /* Turbo button takeover function
61  * Older boards have different values and EC registers
62  * for the same function
63  */
64 #define OXP_OLD_TURBO_SWITCH_REG	0x1E
65 #define OXP_OLD_TURBO_TAKE_VAL		0x01
66 #define OXP_OLD_TURBO_RETURN_VAL	0x00
67 
68 #define OXP_TURBO_SWITCH_REG		0xF1
69 #define OXP_TURBO_TAKE_VAL		0x40
70 #define OXP_TURBO_RETURN_VAL		0x00
71 
72 static const struct dmi_system_id dmi_table[] = {
73 	{
74 		.matches = {
75 			DMI_MATCH(DMI_BOARD_VENDOR, "AOKZOE"),
76 			DMI_EXACT_MATCH(DMI_BOARD_NAME, "AOKZOE A1 AR07"),
77 		},
78 		.driver_data = (void *)aok_zoe_a1,
79 	},
80 	{
81 		.matches = {
82 			DMI_MATCH(DMI_BOARD_VENDOR, "AOKZOE"),
83 			DMI_EXACT_MATCH(DMI_BOARD_NAME, "AOKZOE A1 Pro"),
84 		},
85 		.driver_data = (void *)aok_zoe_a1,
86 	},
87 	{
88 		.matches = {
89 			DMI_MATCH(DMI_BOARD_VENDOR, "AYANEO"),
90 			DMI_EXACT_MATCH(DMI_BOARD_NAME, "AYANEO 2"),
91 		},
92 		.driver_data = (void *)aya_neo_2,
93 	},
94 	{
95 		.matches = {
96 			DMI_MATCH(DMI_BOARD_VENDOR, "AYANEO"),
97 			DMI_EXACT_MATCH(DMI_BOARD_NAME, "AIR"),
98 		},
99 		.driver_data = (void *)aya_neo_air,
100 	},
101 	{
102 		.matches = {
103 			DMI_MATCH(DMI_BOARD_VENDOR, "AYANEO"),
104 			DMI_EXACT_MATCH(DMI_BOARD_NAME, "AIR Pro"),
105 		},
106 		.driver_data = (void *)aya_neo_air_pro,
107 	},
108 	{
109 		.matches = {
110 			DMI_MATCH(DMI_BOARD_VENDOR, "AYANEO"),
111 			DMI_EXACT_MATCH(DMI_BOARD_NAME, "GEEK"),
112 		},
113 		.driver_data = (void *)aya_neo_geek,
114 	},
115 	{
116 		.matches = {
117 			DMI_MATCH(DMI_BOARD_VENDOR, "ONE-NETBOOK"),
118 			DMI_EXACT_MATCH(DMI_BOARD_NAME, "ONE XPLAYER"),
119 		},
120 		.driver_data = (void *)oxp_mini_amd,
121 	},
122 	{
123 		.matches = {
124 			DMI_MATCH(DMI_BOARD_VENDOR, "ONE-NETBOOK"),
125 			DMI_EXACT_MATCH(DMI_BOARD_NAME, "ONEXPLAYER mini A07"),
126 		},
127 		.driver_data = (void *)oxp_mini_amd_a07,
128 	},
129 	{
130 		.matches = {
131 			DMI_MATCH(DMI_BOARD_VENDOR, "ONE-NETBOOK"),
132 			DMI_EXACT_MATCH(DMI_BOARD_NAME, "ONEXPLAYER Mini Pro"),
133 		},
134 		.driver_data = (void *)oxp_mini_amd_pro,
135 	},
136 	{},
137 };
138 
139 /* Helper functions to handle EC read/write */
140 static int read_from_ec(u8 reg, int size, long *val)
141 {
142 	int i;
143 	int ret;
144 	u8 buffer;
145 
146 	if (!lock_global_acpi_lock())
147 		return -EBUSY;
148 
149 	*val = 0;
150 	for (i = 0; i < size; i++) {
151 		ret = ec_read(reg + i, &buffer);
152 		if (ret)
153 			return ret;
154 		*val <<= i * 8;
155 		*val += buffer;
156 	}
157 
158 	if (!unlock_global_acpi_lock())
159 		return -EBUSY;
160 
161 	return 0;
162 }
163 
164 static int write_to_ec(u8 reg, u8 value)
165 {
166 	int ret;
167 
168 	if (!lock_global_acpi_lock())
169 		return -EBUSY;
170 
171 	ret = ec_write(reg, value);
172 
173 	if (!unlock_global_acpi_lock())
174 		return -EBUSY;
175 
176 	return ret;
177 }
178 
179 /* Turbo button toggle functions */
180 static int tt_toggle_enable(void)
181 {
182 	u8 reg;
183 	u8 val;
184 
185 	switch (board) {
186 	case oxp_mini_amd_a07:
187 		reg = OXP_OLD_TURBO_SWITCH_REG;
188 		val = OXP_OLD_TURBO_TAKE_VAL;
189 		break;
190 	case oxp_mini_amd_pro:
191 	case aok_zoe_a1:
192 		reg = OXP_TURBO_SWITCH_REG;
193 		val = OXP_TURBO_TAKE_VAL;
194 		break;
195 	default:
196 		return -EINVAL;
197 	}
198 	return write_to_ec(reg, val);
199 }
200 
201 static int tt_toggle_disable(void)
202 {
203 	u8 reg;
204 	u8 val;
205 
206 	switch (board) {
207 	case oxp_mini_amd_a07:
208 		reg = OXP_OLD_TURBO_SWITCH_REG;
209 		val = OXP_OLD_TURBO_RETURN_VAL;
210 		break;
211 	case oxp_mini_amd_pro:
212 	case aok_zoe_a1:
213 		reg = OXP_TURBO_SWITCH_REG;
214 		val = OXP_TURBO_RETURN_VAL;
215 		break;
216 	default:
217 		return -EINVAL;
218 	}
219 	return write_to_ec(reg, val);
220 }
221 
222 /* Callbacks for turbo toggle attribute */
223 static umode_t tt_toggle_is_visible(struct kobject *kobj,
224 				    struct attribute *attr, int n)
225 {
226 	switch (board) {
227 	case aok_zoe_a1:
228 	case oxp_mini_amd_a07:
229 	case oxp_mini_amd_pro:
230 		return attr->mode;
231 	default:
232 		break;
233 	}
234 	return 0;
235 }
236 
237 static ssize_t tt_toggle_store(struct device *dev,
238 			       struct device_attribute *attr, const char *buf,
239 			       size_t count)
240 {
241 	int rval;
242 	bool value;
243 
244 	rval = kstrtobool(buf, &value);
245 	if (rval)
246 		return rval;
247 
248 	if (value) {
249 		rval = tt_toggle_enable();
250 	} else {
251 		rval = tt_toggle_disable();
252 	}
253 	if (rval)
254 		return rval;
255 
256 	return count;
257 }
258 
259 static ssize_t tt_toggle_show(struct device *dev,
260 			      struct device_attribute *attr, char *buf)
261 {
262 	int retval;
263 	u8 reg;
264 	long val;
265 
266 	switch (board) {
267 	case oxp_mini_amd_a07:
268 		reg = OXP_OLD_TURBO_SWITCH_REG;
269 		break;
270 	case oxp_mini_amd_pro:
271 	case aok_zoe_a1:
272 		reg = OXP_TURBO_SWITCH_REG;
273 		break;
274 	default:
275 		return -EINVAL;
276 	}
277 
278 	retval = read_from_ec(reg, 1, &val);
279 	if (retval)
280 		return retval;
281 
282 	return sysfs_emit(buf, "%d\n", !!val);
283 }
284 
285 static DEVICE_ATTR_RW(tt_toggle);
286 
287 /* PWM enable/disable functions */
288 static int oxp_pwm_enable(void)
289 {
290 	return write_to_ec(OXP_SENSOR_PWM_ENABLE_REG, 0x01);
291 }
292 
293 static int oxp_pwm_disable(void)
294 {
295 	return write_to_ec(OXP_SENSOR_PWM_ENABLE_REG, 0x00);
296 }
297 
298 /* Callbacks for hwmon interface */
299 static umode_t oxp_ec_hwmon_is_visible(const void *drvdata,
300 				       enum hwmon_sensor_types type, u32 attr, int channel)
301 {
302 	switch (type) {
303 	case hwmon_fan:
304 		return 0444;
305 	case hwmon_pwm:
306 		return 0644;
307 	default:
308 		return 0;
309 	}
310 }
311 
312 static int oxp_platform_read(struct device *dev, enum hwmon_sensor_types type,
313 			     u32 attr, int channel, long *val)
314 {
315 	int ret;
316 
317 	switch (type) {
318 	case hwmon_fan:
319 		switch (attr) {
320 		case hwmon_fan_input:
321 			return read_from_ec(OXP_SENSOR_FAN_REG, 2, val);
322 		default:
323 			break;
324 		}
325 		break;
326 	case hwmon_pwm:
327 		switch (attr) {
328 		case hwmon_pwm_input:
329 			ret = read_from_ec(OXP_SENSOR_PWM_REG, 1, val);
330 			if (ret)
331 				return ret;
332 			switch (board) {
333 			case aya_neo_2:
334 			case aya_neo_air:
335 			case aya_neo_air_pro:
336 			case aya_neo_geek:
337 			case oxp_mini_amd:
338 			case oxp_mini_amd_a07:
339 				*val = (*val * 255) / 100;
340 				break;
341 			case oxp_mini_amd_pro:
342 			case aok_zoe_a1:
343 			default:
344 				break;
345 			}
346 			return 0;
347 		case hwmon_pwm_enable:
348 			return read_from_ec(OXP_SENSOR_PWM_ENABLE_REG, 1, val);
349 		default:
350 			break;
351 		}
352 		break;
353 	default:
354 		break;
355 	}
356 	return -EOPNOTSUPP;
357 }
358 
359 static int oxp_platform_write(struct device *dev, enum hwmon_sensor_types type,
360 			      u32 attr, int channel, long val)
361 {
362 	switch (type) {
363 	case hwmon_pwm:
364 		switch (attr) {
365 		case hwmon_pwm_enable:
366 			if (val == 1)
367 				return oxp_pwm_enable();
368 			else if (val == 0)
369 				return oxp_pwm_disable();
370 			return -EINVAL;
371 		case hwmon_pwm_input:
372 			if (val < 0 || val > 255)
373 				return -EINVAL;
374 			switch (board) {
375 			case aya_neo_2:
376 			case aya_neo_air:
377 			case aya_neo_air_pro:
378 			case aya_neo_geek:
379 			case oxp_mini_amd:
380 			case oxp_mini_amd_a07:
381 				val = (val * 100) / 255;
382 				break;
383 			case aok_zoe_a1:
384 			case oxp_mini_amd_pro:
385 			default:
386 				break;
387 			}
388 			return write_to_ec(OXP_SENSOR_PWM_REG, val);
389 		default:
390 			break;
391 		}
392 		break;
393 	default:
394 		break;
395 	}
396 	return -EOPNOTSUPP;
397 }
398 
399 /* Known sensors in the OXP EC controllers */
400 static const struct hwmon_channel_info * const oxp_platform_sensors[] = {
401 	HWMON_CHANNEL_INFO(fan,
402 			   HWMON_F_INPUT),
403 	HWMON_CHANNEL_INFO(pwm,
404 			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE),
405 	NULL,
406 };
407 
408 static struct attribute *oxp_ec_attrs[] = {
409 	&dev_attr_tt_toggle.attr,
410 	NULL
411 };
412 
413 static struct attribute_group oxp_ec_attribute_group = {
414 	.is_visible = tt_toggle_is_visible,
415 	.attrs = oxp_ec_attrs,
416 };
417 
418 static const struct attribute_group *oxp_ec_groups[] = {
419 	&oxp_ec_attribute_group,
420 	NULL
421 };
422 
423 static const struct hwmon_ops oxp_ec_hwmon_ops = {
424 	.is_visible = oxp_ec_hwmon_is_visible,
425 	.read = oxp_platform_read,
426 	.write = oxp_platform_write,
427 };
428 
429 static const struct hwmon_chip_info oxp_ec_chip_info = {
430 	.ops = &oxp_ec_hwmon_ops,
431 	.info = oxp_platform_sensors,
432 };
433 
434 /* Initialization logic */
435 static int oxp_platform_probe(struct platform_device *pdev)
436 {
437 	const struct dmi_system_id *dmi_entry;
438 	struct device *dev = &pdev->dev;
439 	struct device *hwdev;
440 
441 	/*
442 	 * Have to check for AMD processor here because DMI strings are the
443 	 * same between Intel and AMD boards, the only way to tell them apart
444 	 * is the CPU.
445 	 * Intel boards seem to have different EC registers and values to
446 	 * read/write.
447 	 */
448 	dmi_entry = dmi_first_match(dmi_table);
449 	if (!dmi_entry || boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
450 		return -ENODEV;
451 
452 	board = (enum oxp_board)(unsigned long)dmi_entry->driver_data;
453 
454 	hwdev = devm_hwmon_device_register_with_info(dev, "oxpec", NULL,
455 						     &oxp_ec_chip_info, NULL);
456 
457 	return PTR_ERR_OR_ZERO(hwdev);
458 }
459 
460 static struct platform_driver oxp_platform_driver = {
461 	.driver = {
462 		.name = "oxp-platform",
463 		.dev_groups = oxp_ec_groups,
464 	},
465 	.probe = oxp_platform_probe,
466 };
467 
468 static struct platform_device *oxp_platform_device;
469 
470 static int __init oxp_platform_init(void)
471 {
472 	oxp_platform_device =
473 		platform_create_bundle(&oxp_platform_driver,
474 				       oxp_platform_probe, NULL, 0, NULL, 0);
475 
476 	return PTR_ERR_OR_ZERO(oxp_platform_device);
477 }
478 
479 static void __exit oxp_platform_exit(void)
480 {
481 	platform_device_unregister(oxp_platform_device);
482 	platform_driver_unregister(&oxp_platform_driver);
483 }
484 
485 MODULE_DEVICE_TABLE(dmi, dmi_table);
486 
487 module_init(oxp_platform_init);
488 module_exit(oxp_platform_exit);
489 
490 MODULE_AUTHOR("Joaquín Ignacio Aramendía <samsagax@gmail.com>");
491 MODULE_DESCRIPTION("Platform driver that handles EC sensors of OneXPlayer devices");
492 MODULE_LICENSE("GPL");
493