1 // SPDX-License-Identifier: GPL-2.0
2 /* Author: Dan Scally <djrscally@gmail.com> */
3 
4 #include <linux/acpi.h>
5 #include <linux/clkdev.h>
6 #include <linux/clk-provider.h>
7 #include <linux/device.h>
8 #include <linux/gpio/consumer.h>
9 #include <linux/gpio/machine.h>
10 #include <linux/i2c.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/overflow.h>
14 #include <linux/platform_device.h>
15 #include <linux/uuid.h>
16 
17 #include "common.h"
18 
19 /*
20  * 79234640-9e10-4fea-a5c1-b5aa8b19756f
21  * This _DSM GUID returns information about the GPIO lines mapped to a
22  * discrete INT3472 device. Function number 1 returns a count of the GPIO
23  * lines that are mapped. Subsequent functions return 32 bit ints encoding
24  * information about the GPIO line, including its purpose.
25  */
26 static const guid_t int3472_gpio_guid =
27 	GUID_INIT(0x79234640, 0x9e10, 0x4fea,
28 		  0xa5, 0xc1, 0xb5, 0xaa, 0x8b, 0x19, 0x75, 0x6f);
29 
30 /*
31  * 822ace8f-2814-4174-a56b-5f029fe079ee
32  * This _DSM GUID returns a string from the sensor device, which acts as a
33  * module identifier.
34  */
35 static const guid_t cio2_sensor_module_guid =
36 	GUID_INIT(0x822ace8f, 0x2814, 0x4174,
37 		  0xa5, 0x6b, 0x5f, 0x02, 0x9f, 0xe0, 0x79, 0xee);
38 
39 /*
40  * Here follows platform specific mapping information that we can pass to
41  * the functions mapping resources to the sensors. Where the sensors have
42  * a power enable pin defined in DSDT we need to provide a supply name so
43  * the sensor drivers can find the regulator. The device name will be derived
44  * from the sensor's ACPI device within the code. Optionally, we can provide a
45  * NULL terminated array of function name mappings to deal with any platform
46  * specific deviations from the documented behaviour of GPIOs.
47  *
48  * Map a GPIO function name to NULL to prevent the driver from mapping that
49  * GPIO at all.
50  */
51 
52 static const struct int3472_gpio_function_remap ov2680_gpio_function_remaps[] = {
53 	{ "reset", NULL },
54 	{ "powerdown", "reset" },
55 	{ }
56 };
57 
58 static const struct int3472_sensor_config int3472_sensor_configs[] = {
59 	/* Lenovo Miix 510-12ISK - OV2680, Front */
60 	{ "GNDF140809R", { 0 }, ov2680_gpio_function_remaps },
61 	/* Lenovo Miix 510-12ISK - OV5648, Rear */
62 	{ "GEFF150023R", REGULATOR_SUPPLY("avdd", NULL), NULL },
63 	/* Surface Go 1&2 - OV5693, Front */
64 	{ "YHCU", REGULATOR_SUPPLY("avdd", NULL), NULL },
65 };
66 
67 static const struct int3472_sensor_config *
68 skl_int3472_get_sensor_module_config(struct int3472_discrete_device *int3472)
69 {
70 	union acpi_object *obj;
71 	unsigned int i;
72 
73 	obj = acpi_evaluate_dsm_typed(int3472->sensor->handle,
74 				      &cio2_sensor_module_guid, 0x00,
75 				      0x01, NULL, ACPI_TYPE_STRING);
76 
77 	if (!obj) {
78 		dev_err(int3472->dev,
79 			"Failed to get sensor module string from _DSM\n");
80 		return ERR_PTR(-ENODEV);
81 	}
82 
83 	if (obj->string.type != ACPI_TYPE_STRING) {
84 		dev_err(int3472->dev,
85 			"Sensor _DSM returned a non-string value\n");
86 
87 		ACPI_FREE(obj);
88 		return ERR_PTR(-EINVAL);
89 	}
90 
91 	for (i = 0; i < ARRAY_SIZE(int3472_sensor_configs); i++) {
92 		if (!strcmp(int3472_sensor_configs[i].sensor_module_name,
93 			    obj->string.pointer))
94 			break;
95 	}
96 
97 	ACPI_FREE(obj);
98 
99 	if (i >= ARRAY_SIZE(int3472_sensor_configs))
100 		return ERR_PTR(-EINVAL);
101 
102 	return &int3472_sensor_configs[i];
103 }
104 
105 static int skl_int3472_map_gpio_to_sensor(struct int3472_discrete_device *int3472,
106 					  struct acpi_resource_gpio *agpio,
107 					  const char *func, u32 polarity)
108 {
109 	const struct int3472_sensor_config *sensor_config;
110 	char *path = agpio->resource_source.string_ptr;
111 	struct gpiod_lookup *table_entry;
112 	struct acpi_device *adev;
113 	acpi_handle handle;
114 	acpi_status status;
115 
116 	if (int3472->n_sensor_gpios >= INT3472_MAX_SENSOR_GPIOS) {
117 		dev_warn(int3472->dev, "Too many GPIOs mapped\n");
118 		return -EINVAL;
119 	}
120 
121 	sensor_config = int3472->sensor_config;
122 	if (!IS_ERR(sensor_config) && sensor_config->function_maps) {
123 		const struct int3472_gpio_function_remap *remap;
124 
125 		for (remap = sensor_config->function_maps; remap->documented; remap++) {
126 			if (!strcmp(func, remap->documented)) {
127 				func = remap->actual;
128 				break;
129 			}
130 		}
131 	}
132 
133 	/* Functions mapped to NULL should not be mapped to the sensor */
134 	if (!func)
135 		return 0;
136 
137 	status = acpi_get_handle(NULL, path, &handle);
138 	if (ACPI_FAILURE(status))
139 		return -EINVAL;
140 
141 	adev = acpi_fetch_acpi_dev(handle);
142 	if (!adev)
143 		return -ENODEV;
144 
145 	table_entry = &int3472->gpios.table[int3472->n_sensor_gpios];
146 	table_entry->key = acpi_dev_name(adev);
147 	table_entry->chip_hwnum = agpio->pin_table[0];
148 	table_entry->con_id = func;
149 	table_entry->idx = 0;
150 	table_entry->flags = polarity;
151 
152 	int3472->n_sensor_gpios++;
153 
154 	return 0;
155 }
156 
157 static int skl_int3472_map_gpio_to_clk(struct int3472_discrete_device *int3472,
158 				       struct acpi_resource_gpio *agpio, u8 type)
159 {
160 	char *path = agpio->resource_source.string_ptr;
161 	u16 pin = agpio->pin_table[0];
162 	struct gpio_desc *gpio;
163 
164 	switch (type) {
165 	case INT3472_GPIO_TYPE_CLK_ENABLE:
166 		gpio = acpi_get_and_request_gpiod(path, pin, "int3472,clk-enable");
167 		if (IS_ERR(gpio))
168 			return (PTR_ERR(gpio));
169 
170 		int3472->clock.ena_gpio = gpio;
171 		break;
172 	case INT3472_GPIO_TYPE_PRIVACY_LED:
173 		gpio = acpi_get_and_request_gpiod(path, pin, "int3472,privacy-led");
174 		if (IS_ERR(gpio))
175 			return (PTR_ERR(gpio));
176 
177 		int3472->clock.led_gpio = gpio;
178 		break;
179 	default:
180 		dev_err(int3472->dev, "Invalid GPIO type 0x%02x for clock\n", type);
181 		break;
182 	}
183 
184 	return 0;
185 }
186 
187 /**
188  * skl_int3472_handle_gpio_resources: Map PMIC resources to consuming sensor
189  * @ares: A pointer to a &struct acpi_resource
190  * @data: A pointer to a &struct int3472_discrete_device
191  *
192  * This function handles GPIO resources that are against an INT3472
193  * ACPI device, by checking the value of the corresponding _DSM entry.
194  * This will return a 32bit int, where the lowest byte represents the
195  * function of the GPIO pin:
196  *
197  * 0x00 Reset
198  * 0x01 Power down
199  * 0x0b Power enable
200  * 0x0c Clock enable
201  * 0x0d Privacy LED
202  *
203  * There are some known platform specific quirks where that does not quite
204  * hold up; for example where a pin with type 0x01 (Power down) is mapped to
205  * a sensor pin that performs a reset function or entries in _CRS and _DSM that
206  * do not actually correspond to a physical connection. These will be handled
207  * by the mapping sub-functions.
208  *
209  * GPIOs will either be mapped directly to the sensor device or else used
210  * to create clocks and regulators via the usual frameworks.
211  *
212  * Return:
213  * * 1		- To continue the loop
214  * * 0		- When all resources found are handled properly.
215  * * -EINVAL	- If the resource is not a GPIO IO resource
216  * * -ENODEV	- If the resource has no corresponding _DSM entry
217  * * -Other	- Errors propagated from one of the sub-functions.
218  */
219 static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares,
220 					     void *data)
221 {
222 	struct int3472_discrete_device *int3472 = data;
223 	struct acpi_resource_gpio *agpio;
224 	union acpi_object *obj;
225 	const char *err_msg;
226 	int ret;
227 	u8 type;
228 
229 	if (!acpi_gpio_get_io_resource(ares, &agpio))
230 		return 1;
231 
232 	/*
233 	 * ngpios + 2 because the index of this _DSM function is 1-based and
234 	 * the first function is just a count.
235 	 */
236 	obj = acpi_evaluate_dsm_typed(int3472->adev->handle,
237 				      &int3472_gpio_guid, 0x00,
238 				      int3472->ngpios + 2,
239 				      NULL, ACPI_TYPE_INTEGER);
240 
241 	if (!obj) {
242 		dev_warn(int3472->dev, "No _DSM entry for GPIO pin %u\n",
243 			 agpio->pin_table[0]);
244 		return 1;
245 	}
246 
247 	type = obj->integer.value & 0xff;
248 
249 	switch (type) {
250 	case INT3472_GPIO_TYPE_RESET:
251 		ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, "reset",
252 						     GPIO_ACTIVE_LOW);
253 		if (ret)
254 			err_msg = "Failed to map reset pin to sensor\n";
255 
256 		break;
257 	case INT3472_GPIO_TYPE_POWERDOWN:
258 		ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, "powerdown",
259 						     GPIO_ACTIVE_LOW);
260 		if (ret)
261 			err_msg = "Failed to map powerdown pin to sensor\n";
262 
263 		break;
264 	case INT3472_GPIO_TYPE_CLK_ENABLE:
265 	case INT3472_GPIO_TYPE_PRIVACY_LED:
266 		ret = skl_int3472_map_gpio_to_clk(int3472, agpio, type);
267 		if (ret)
268 			err_msg = "Failed to map GPIO to clock\n";
269 
270 		break;
271 	case INT3472_GPIO_TYPE_POWER_ENABLE:
272 		ret = skl_int3472_register_regulator(int3472, agpio);
273 		if (ret)
274 			err_msg = "Failed to map regulator to sensor\n";
275 
276 		break;
277 	default:
278 		dev_warn(int3472->dev,
279 			 "GPIO type 0x%02x unknown; the sensor may not work\n",
280 			 type);
281 		ret = 1;
282 		break;
283 	}
284 
285 	int3472->ngpios++;
286 	ACPI_FREE(obj);
287 
288 	if (ret < 0)
289 		return dev_err_probe(int3472->dev, ret, err_msg);
290 
291 	return ret;
292 }
293 
294 static int skl_int3472_parse_crs(struct int3472_discrete_device *int3472)
295 {
296 	LIST_HEAD(resource_list);
297 	int ret;
298 
299 	/*
300 	 * No error check, because not having a sensor config is not necessarily
301 	 * a failure mode.
302 	 */
303 	int3472->sensor_config = skl_int3472_get_sensor_module_config(int3472);
304 
305 	ret = acpi_dev_get_resources(int3472->adev, &resource_list,
306 				     skl_int3472_handle_gpio_resources,
307 				     int3472);
308 	if (ret < 0)
309 		return ret;
310 
311 	acpi_dev_free_resource_list(&resource_list);
312 
313 	/*
314 	 * If we find no clock enable GPIO pin then the privacy LED won't work.
315 	 * We've never seen that situation, but it's possible. Warn the user so
316 	 * it's clear what's happened.
317 	 */
318 	if (int3472->clock.ena_gpio) {
319 		ret = skl_int3472_register_clock(int3472);
320 		if (ret)
321 			return ret;
322 	} else {
323 		if (int3472->clock.led_gpio)
324 			dev_warn(int3472->dev,
325 				 "No clk GPIO. The privacy LED won't work\n");
326 	}
327 
328 	int3472->gpios.dev_id = int3472->sensor_name;
329 	gpiod_add_lookup_table(&int3472->gpios);
330 
331 	return 0;
332 }
333 
334 static int skl_int3472_discrete_remove(struct platform_device *pdev);
335 
336 static int skl_int3472_discrete_probe(struct platform_device *pdev)
337 {
338 	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
339 	struct int3472_discrete_device *int3472;
340 	struct int3472_cldb cldb;
341 	int ret;
342 
343 	ret = skl_int3472_fill_cldb(adev, &cldb);
344 	if (ret) {
345 		dev_err(&pdev->dev, "Couldn't fill CLDB structure\n");
346 		return ret;
347 	}
348 
349 	if (cldb.control_logic_type != 1) {
350 		dev_err(&pdev->dev, "Unsupported control logic type %u\n",
351 			cldb.control_logic_type);
352 		return -EINVAL;
353 	}
354 
355 	/* Max num GPIOs we've seen plus a terminator */
356 	int3472 = devm_kzalloc(&pdev->dev, struct_size(int3472, gpios.table,
357 			       INT3472_MAX_SENSOR_GPIOS + 1), GFP_KERNEL);
358 	if (!int3472)
359 		return -ENOMEM;
360 
361 	int3472->adev = adev;
362 	int3472->dev = &pdev->dev;
363 	platform_set_drvdata(pdev, int3472);
364 
365 	ret = skl_int3472_get_sensor_adev_and_name(&pdev->dev, &int3472->sensor,
366 						   &int3472->sensor_name);
367 	if (ret)
368 		return ret;
369 
370 	/*
371 	 * Initialising this list means we can call gpiod_remove_lookup_table()
372 	 * in failure paths without issue.
373 	 */
374 	INIT_LIST_HEAD(&int3472->gpios.list);
375 
376 	ret = skl_int3472_parse_crs(int3472);
377 	if (ret) {
378 		skl_int3472_discrete_remove(pdev);
379 		return ret;
380 	}
381 
382 	acpi_dev_clear_dependencies(adev);
383 	return 0;
384 }
385 
386 static int skl_int3472_discrete_remove(struct platform_device *pdev)
387 {
388 	struct int3472_discrete_device *int3472 = platform_get_drvdata(pdev);
389 
390 	gpiod_remove_lookup_table(&int3472->gpios);
391 
392 	if (int3472->clock.cl)
393 		skl_int3472_unregister_clock(int3472);
394 
395 	gpiod_put(int3472->clock.ena_gpio);
396 	gpiod_put(int3472->clock.led_gpio);
397 
398 	skl_int3472_unregister_regulator(int3472);
399 
400 	return 0;
401 }
402 
403 static const struct acpi_device_id int3472_device_id[] = {
404 	{ "INT3472", 0 },
405 	{ }
406 };
407 MODULE_DEVICE_TABLE(acpi, int3472_device_id);
408 
409 static struct platform_driver int3472_discrete = {
410 	.driver = {
411 		.name = "int3472-discrete",
412 		.acpi_match_table = int3472_device_id,
413 	},
414 	.probe = skl_int3472_discrete_probe,
415 	.remove = skl_int3472_discrete_remove,
416 };
417 module_platform_driver(int3472_discrete);
418 
419 MODULE_DESCRIPTION("Intel SkyLake INT3472 ACPI Discrete Device Driver");
420 MODULE_AUTHOR("Daniel Scally <djrscally@gmail.com>");
421 MODULE_LICENSE("GPL v2");
422