summaryrefslogtreecommitdiffstats
path: root/drivers/platform/x86/intel/int3472/discrete.c
blob: c42c3faa2c32da504f6c0757588b5ff77bb9bc32 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
// SPDX-License-Identifier: GPL-2.0
/* Author: Dan Scally <djrscally@gmail.com> */

#include <linux/acpi.h>
#include <linux/clkdev.h>
#include <linux/clk-provider.h>
#include <linux/device.h>
#include <linux/gpio/consumer.h>
#include <linux/gpio/machine.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/overflow.h>
#include <linux/platform_device.h>
#include <linux/uuid.h>

#include "common.h"

/*
 * 79234640-9e10-4fea-a5c1-b5aa8b19756f
 * This _DSM GUID returns information about the GPIO lines mapped to a
 * discrete INT3472 device. Function number 1 returns a count of the GPIO
 * lines that are mapped. Subsequent functions return 32 bit ints encoding
 * information about the GPIO line, including its purpose.
 */
static const guid_t int3472_gpio_guid =
	GUID_INIT(0x79234640, 0x9e10, 0x4fea,
		  0xa5, 0xc1, 0xb5, 0xaa, 0x8b, 0x19, 0x75, 0x6f);

/*
 * 822ace8f-2814-4174-a56b-5f029fe079ee
 * This _DSM GUID returns a string from the sensor device, which acts as a
 * module identifier.
 */
static const guid_t cio2_sensor_module_guid =
	GUID_INIT(0x822ace8f, 0x2814, 0x4174,
		  0xa5, 0x6b, 0x5f, 0x02, 0x9f, 0xe0, 0x79, 0xee);

/*
 * Here follows platform specific mapping information that we can pass to
 * the functions mapping resources to the sensors. Where the sensors have
 * a power enable pin defined in DSDT we need to provide a supply name so
 * the sensor drivers can find the regulator. The device name will be derived
 * from the sensor's ACPI device within the code. Optionally, we can provide a
 * NULL terminated array of function name mappings to deal with any platform
 * specific deviations from the documented behaviour of GPIOs.
 *
 * Map a GPIO function name to NULL to prevent the driver from mapping that
 * GPIO at all.
 */

static const struct int3472_gpio_function_remap ov2680_gpio_function_remaps[] = {
	{ "reset", NULL },
	{ "powerdown", "reset" },
	{ }
};

static const struct int3472_sensor_config int3472_sensor_configs[] = {
	/* Lenovo Miix 510-12ISK - OV2680, Front */
	{ "GNDF140809R", { 0 }, ov2680_gpio_function_remaps },
	/* Lenovo Miix 510-12ISK - OV5648, Rear */
	{ "GEFF150023R", REGULATOR_SUPPLY("avdd", NULL), NULL },
	/* Surface Go 1&2 - OV5693, Front */
	{ "YHCU", REGULATOR_SUPPLY("avdd", NULL), NULL },
};

static const struct int3472_sensor_config *
skl_int3472_get_sensor_module_config(struct int3472_discrete_device *int3472)
{
	union acpi_object *obj;
	unsigned int i;

	obj = acpi_evaluate_dsm_typed(int3472->sensor->handle,
				      &cio2_sensor_module_guid, 0x00,
				      0x01, NULL, ACPI_TYPE_STRING);

	if (!obj) {
		dev_err(int3472->dev,
			"Failed to get sensor module string from _DSM\n");
		return ERR_PTR(-ENODEV);
	}

	if (obj->string.type != ACPI_TYPE_STRING) {
		dev_err(int3472->dev,
			"Sensor _DSM returned a non-string value\n");

		ACPI_FREE(obj);
		return ERR_PTR(-EINVAL);
	}

	for (i = 0; i < ARRAY_SIZE(int3472_sensor_configs); i++) {
		if (!strcmp(int3472_sensor_configs[i].sensor_module_name,
			    obj->string.pointer))
			break;
	}

	ACPI_FREE(obj);

	if (i >= ARRAY_SIZE(int3472_sensor_configs))
		return ERR_PTR(-EINVAL);

	return &int3472_sensor_configs[i];
}

static int skl_int3472_map_gpio_to_sensor(struct int3472_discrete_device *int3472,
					  struct acpi_resource_gpio *agpio,
					  const char *func, u32 polarity)
{
	const struct int3472_sensor_config *sensor_config;
	char *path = agpio->resource_source.string_ptr;
	struct gpiod_lookup *table_entry;
	struct acpi_device *adev;
	acpi_handle handle;
	acpi_status status;

	if (int3472->n_sensor_gpios >= INT3472_MAX_SENSOR_GPIOS) {
		dev_warn(int3472->dev, "Too many GPIOs mapped\n");
		return -EINVAL;
	}

	sensor_config = int3472->sensor_config;
	if (!IS_ERR(sensor_config) && sensor_config->function_maps) {
		const struct int3472_gpio_function_remap *remap;

		for (remap = sensor_config->function_maps; remap->documented; remap++) {
			if (!strcmp(func, remap->documented)) {
				func = remap->actual;
				break;
			}
		}
	}

	/* Functions mapped to NULL should not be mapped to the sensor */
	if (!func)
		return 0;

	status = acpi_get_handle(NULL, path, &handle);
	if (ACPI_FAILURE(status))
		return -EINVAL;

	adev = acpi_fetch_acpi_dev(handle);
	if (!adev)
		return -ENODEV;

	table_entry = &int3472->gpios.table[int3472->n_sensor_gpios];
	table_entry->key = acpi_dev_name(adev);
	table_entry->chip_hwnum = agpio->pin_table[0];
	table_entry->con_id = func;
	table_entry->idx = 0;
	table_entry->flags = polarity;

	int3472->n_sensor_gpios++;

	return 0;
}

static int skl_int3472_map_gpio_to_clk(struct int3472_discrete_device *int3472,
				       struct acpi_resource_gpio *agpio, u8 type)
{
	char *path = agpio->resource_source.string_ptr;
	u16 pin = agpio->pin_table[0];
	struct gpio_desc *gpio;

	switch (type) {
	case INT3472_GPIO_TYPE_CLK_ENABLE:
		gpio = acpi_get_and_request_gpiod(path, pin, "int3472,clk-enable");
		if (IS_ERR(gpio))
			return (PTR_ERR(gpio));

		int3472->clock.ena_gpio = gpio;
		/* Ensure the pin is in output mode and non-active state */
		gpiod_direction_output(int3472->clock.ena_gpio, 0);
		break;
	case INT3472_GPIO_TYPE_PRIVACY_LED:
		gpio = acpi_get_and_request_gpiod(path, pin, "int3472,privacy-led");
		if (IS_ERR(gpio))
			return (PTR_ERR(gpio));

		int3472->clock.led_gpio = gpio;
		/* Ensure the pin is in output mode and non-active state */
		gpiod_direction_output(int3472->clock.led_gpio, 0);
		break;
	default:
		dev_err(int3472->dev, "Invalid GPIO type 0x%02x for clock\n", type);
		break;
	}

	return 0;
}

/**
 * skl_int3472_handle_gpio_resources: Map PMIC resources to consuming sensor
 * @ares: A pointer to a &struct acpi_resource
 * @data: A pointer to a &struct int3472_discrete_device
 *
 * This function handles GPIO resources that are against an INT3472
 * ACPI device, by checking the value of the corresponding _DSM entry.
 * This will return a 32bit int, where the lowest byte represents the
 * function of the GPIO pin:
 *
 * 0x00 Reset
 * 0x01 Power down
 * 0x0b Power enable
 * 0x0c Clock enable
 * 0x0d Privacy LED
 *
 * There are some known platform specific quirks where that does not quite
 * hold up; for example where a pin with type 0x01 (Power down) is mapped to
 * a sensor pin that performs a reset function or entries in _CRS and _DSM that
 * do not actually correspond to a physical connection. These will be handled
 * by the mapping sub-functions.
 *
 * GPIOs will either be mapped directly to the sensor device or else used
 * to create clocks and regulators via the usual frameworks.
 *
 * Return:
 * * 1		- To continue the loop
 * * 0		- When all resources found are handled properly.
 * * -EINVAL	- If the resource is not a GPIO IO resource
 * * -ENODEV	- If the resource has no corresponding _DSM entry
 * * -Other	- Errors propagated from one of the sub-functions.
 */
static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares,
					     void *data)
{
	struct int3472_discrete_device *int3472 = data;
	struct acpi_resource_gpio *agpio;
	union acpi_object *obj;
	const char *err_msg;
	int ret;
	u8 type;

	if (!acpi_gpio_get_io_resource(ares, &agpio))
		return 1;

	/*
	 * ngpios + 2 because the index of this _DSM function is 1-based and
	 * the first function is just a count.
	 */
	obj = acpi_evaluate_dsm_typed(int3472->adev->handle,
				      &int3472_gpio_guid, 0x00,
				      int3472->ngpios + 2,
				      NULL, ACPI_TYPE_INTEGER);

	if (!obj) {
		dev_warn(int3472->dev, "No _DSM entry for GPIO pin %u\n",
			 agpio->pin_table[0]);
		return 1;
	}

	type = obj->integer.value & 0xff;

	switch (type) {
	case INT3472_GPIO_TYPE_RESET:
		ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, "reset",
						     GPIO_ACTIVE_LOW);
		if (ret)
			err_msg = "Failed to map reset pin to sensor\n";

		break;
	case INT3472_GPIO_TYPE_POWERDOWN:
		ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, "powerdown",
						     GPIO_ACTIVE_LOW);
		if (ret)
			err_msg = "Failed to map powerdown pin to sensor\n";

		break;
	case INT3472_GPIO_TYPE_CLK_ENABLE:
	case INT3472_GPIO_TYPE_PRIVACY_LED:
		ret = skl_int3472_map_gpio_to_clk(int3472, agpio, type);
		if (ret)
			err_msg = "Failed to map GPIO to clock\n";

		break;
	case INT3472_GPIO_TYPE_POWER_ENABLE:
		ret = skl_int3472_register_regulator(int3472, agpio);
		if (ret)
			err_msg = "Failed to map regulator to sensor\n";

		break;
	default:
		dev_warn(int3472->dev,
			 "GPIO type 0x%02x unknown; the sensor may not work\n",
			 type);
		ret = 1;
		break;
	}

	int3472->ngpios++;
	ACPI_FREE(obj);

	if (ret < 0)
		return dev_err_probe(int3472->dev, ret, err_msg);

	return ret;
}

static int skl_int3472_parse_crs(struct int3472_discrete_device *int3472)
{
	LIST_HEAD(resource_list);
	int ret;

	/*
	 * No error check, because not having a sensor config is not necessarily
	 * a failure mode.
	 */
	int3472->sensor_config = skl_int3472_get_sensor_module_config(int3472);

	ret = acpi_dev_get_resources(int3472->adev, &resource_list,
				     skl_int3472_handle_gpio_resources,
				     int3472);
	if (ret < 0)
		return ret;

	acpi_dev_free_resource_list(&resource_list);

	/*
	 * If we find no clock enable GPIO pin then the privacy LED won't work.
	 * We've never seen that situation, but it's possible. Warn the user so
	 * it's clear what's happened.
	 */
	if (int3472->clock.ena_gpio) {
		ret = skl_int3472_register_clock(int3472);
		if (ret)
			return ret;
	} else {
		if (int3472->clock.led_gpio)
			dev_warn(int3472->dev,
				 "No clk GPIO. The privacy LED won't work\n");
	}

	int3472->gpios.dev_id = int3472->sensor_name;
	gpiod_add_lookup_table(&int3472->gpios);

	return 0;
}

static int skl_int3472_discrete_remove(struct platform_device *pdev)
{
	struct int3472_discrete_device *int3472 = platform_get_drvdata(pdev);

	gpiod_remove_lookup_table(&int3472->gpios);

	if (int3472->clock.cl)
		skl_int3472_unregister_clock(int3472);

	gpiod_put(int3472->clock.ena_gpio);
	gpiod_put(int3472->clock.led_gpio);

	skl_int3472_unregister_regulator(int3472);

	return 0;
}

static int skl_int3472_discrete_probe(struct platform_device *pdev)
{
	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
	struct int3472_discrete_device *int3472;
	struct int3472_cldb cldb;
	int ret;

	ret = skl_int3472_fill_cldb(adev, &cldb);
	if (ret) {
		dev_err(&pdev->dev, "Couldn't fill CLDB structure\n");
		return ret;
	}

	if (cldb.control_logic_type != 1) {
		dev_err(&pdev->dev, "Unsupported control logic type %u\n",
			cldb.control_logic_type);
		return -EINVAL;
	}

	/* Max num GPIOs we've seen plus a terminator */
	int3472 = devm_kzalloc(&pdev->dev, struct_size(int3472, gpios.table,
			       INT3472_MAX_SENSOR_GPIOS + 1), GFP_KERNEL);
	if (!int3472)
		return -ENOMEM;

	int3472->adev = adev;
	int3472->dev = &pdev->dev;
	platform_set_drvdata(pdev, int3472);

	ret = skl_int3472_get_sensor_adev_and_name(&pdev->dev, &int3472->sensor,
						   &int3472->sensor_name);
	if (ret)
		return ret;

	/*
	 * Initialising this list means we can call gpiod_remove_lookup_table()
	 * in failure paths without issue.
	 */
	INIT_LIST_HEAD(&int3472->gpios.list);

	ret = skl_int3472_parse_crs(int3472);
	if (ret) {
		skl_int3472_discrete_remove(pdev);
		return ret;
	}

	acpi_dev_clear_dependencies(adev);
	return 0;
}

static const struct acpi_device_id int3472_device_id[] = {
	{ "INT3472", 0 },
	{ }
};
MODULE_DEVICE_TABLE(acpi, int3472_device_id);

static struct platform_driver int3472_discrete = {
	.driver = {
		.name = "int3472-discrete",
		.acpi_match_table = int3472_device_id,
	},
	.probe = skl_int3472_discrete_probe,
	.remove = skl_int3472_discrete_remove,
};
module_platform_driver(int3472_discrete);

MODULE_DESCRIPTION("Intel SkyLake INT3472 ACPI Discrete Device Driver");
MODULE_AUTHOR("Daniel Scally <djrscally@gmail.com>");
MODULE_LICENSE("GPL v2");