1 // SPDX-License-Identifier: GPL-2.0
2 /* Author: Dan Scally <djrscally@gmail.com> */
3 
4 #include <linux/acpi.h>
5 #include <linux/device.h>
6 #include <linux/gpio/consumer.h>
7 #include <linux/gpio/machine.h>
8 #include <linux/i2c.h>
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/overflow.h>
12 #include <linux/platform_device.h>
13 #include <linux/uuid.h>
14 
15 #include "common.h"
16 
17 /*
18  * 79234640-9e10-4fea-a5c1-b5aa8b19756f
19  * This _DSM GUID returns information about the GPIO lines mapped to a
20  * discrete INT3472 device. Function number 1 returns a count of the GPIO
21  * lines that are mapped. Subsequent functions return 32 bit ints encoding
22  * information about the GPIO line, including its purpose.
23  */
24 static const guid_t int3472_gpio_guid =
25 	GUID_INIT(0x79234640, 0x9e10, 0x4fea,
26 		  0xa5, 0xc1, 0xb5, 0xaa, 0x8b, 0x19, 0x75, 0x6f);
27 
28 /*
29  * 822ace8f-2814-4174-a56b-5f029fe079ee
30  * This _DSM GUID returns a string from the sensor device, which acts as a
31  * module identifier.
32  */
33 static const guid_t cio2_sensor_module_guid =
34 	GUID_INIT(0x822ace8f, 0x2814, 0x4174,
35 		  0xa5, 0x6b, 0x5f, 0x02, 0x9f, 0xe0, 0x79, 0xee);
36 
37 /*
38  * Here follows platform specific mapping information that we can pass to
39  * the functions mapping resources to the sensors. Where the sensors have
40  * a power enable pin defined in DSDT we need to provide a supply name so
41  * the sensor drivers can find the regulator. The device name will be derived
42  * from the sensor's ACPI device within the code. Optionally, we can provide a
43  * NULL terminated array of function name mappings to deal with any platform
44  * specific deviations from the documented behaviour of GPIOs.
45  *
46  * Map a GPIO function name to NULL to prevent the driver from mapping that
47  * GPIO at all.
48  */
49 
50 static const struct int3472_gpio_function_remap ov2680_gpio_function_remaps[] = {
51 	{ "reset", NULL },
52 	{ "powerdown", "reset" },
53 	{ }
54 };
55 
56 static const struct int3472_sensor_config int3472_sensor_configs[] = {
57 	/* Lenovo Miix 510-12ISK - OV2680, Front */
58 	{ "GNDF140809R", { 0 }, ov2680_gpio_function_remaps },
59 	/* Lenovo Miix 510-12ISK - OV5648, Rear */
60 	{ "GEFF150023R", REGULATOR_SUPPLY("avdd", NULL), NULL },
61 	/* Surface Go 1&2 - OV5693, Front */
62 	{ "YHCU", REGULATOR_SUPPLY("avdd", NULL), NULL },
63 };
64 
65 static const struct int3472_sensor_config *
66 skl_int3472_get_sensor_module_config(struct int3472_discrete_device *int3472)
67 {
68 	union acpi_object *obj;
69 	unsigned int i;
70 
71 	obj = acpi_evaluate_dsm_typed(int3472->sensor->handle,
72 				      &cio2_sensor_module_guid, 0x00,
73 				      0x01, NULL, ACPI_TYPE_STRING);
74 
75 	if (!obj) {
76 		dev_err(int3472->dev,
77 			"Failed to get sensor module string from _DSM\n");
78 		return ERR_PTR(-ENODEV);
79 	}
80 
81 	for (i = 0; i < ARRAY_SIZE(int3472_sensor_configs); i++) {
82 		if (!strcmp(int3472_sensor_configs[i].sensor_module_name,
83 			    obj->string.pointer))
84 			break;
85 	}
86 
87 	ACPI_FREE(obj);
88 
89 	if (i >= ARRAY_SIZE(int3472_sensor_configs))
90 		return ERR_PTR(-EINVAL);
91 
92 	return &int3472_sensor_configs[i];
93 }
94 
95 static int skl_int3472_map_gpio_to_sensor(struct int3472_discrete_device *int3472,
96 					  struct acpi_resource_gpio *agpio,
97 					  const char *func, u32 polarity)
98 {
99 	const struct int3472_sensor_config *sensor_config;
100 	char *path = agpio->resource_source.string_ptr;
101 	struct gpiod_lookup *table_entry;
102 	struct acpi_device *adev;
103 	acpi_handle handle;
104 	acpi_status status;
105 
106 	if (int3472->n_sensor_gpios >= INT3472_MAX_SENSOR_GPIOS) {
107 		dev_warn(int3472->dev, "Too many GPIOs mapped\n");
108 		return -EINVAL;
109 	}
110 
111 	sensor_config = int3472->sensor_config;
112 	if (!IS_ERR(sensor_config) && sensor_config->function_maps) {
113 		const struct int3472_gpio_function_remap *remap;
114 
115 		for (remap = sensor_config->function_maps; remap->documented; remap++) {
116 			if (!strcmp(func, remap->documented)) {
117 				func = remap->actual;
118 				break;
119 			}
120 		}
121 	}
122 
123 	/* Functions mapped to NULL should not be mapped to the sensor */
124 	if (!func)
125 		return 0;
126 
127 	status = acpi_get_handle(NULL, path, &handle);
128 	if (ACPI_FAILURE(status))
129 		return -EINVAL;
130 
131 	adev = acpi_fetch_acpi_dev(handle);
132 	if (!adev)
133 		return -ENODEV;
134 
135 	table_entry = &int3472->gpios.table[int3472->n_sensor_gpios];
136 	table_entry->key = acpi_dev_name(adev);
137 	table_entry->chip_hwnum = agpio->pin_table[0];
138 	table_entry->con_id = func;
139 	table_entry->idx = 0;
140 	table_entry->flags = polarity;
141 
142 	int3472->n_sensor_gpios++;
143 
144 	return 0;
145 }
146 
147 static void int3472_get_func_and_polarity(u8 type, const char **func, u32 *polarity)
148 {
149 	switch (type) {
150 	case INT3472_GPIO_TYPE_RESET:
151 		*func = "reset";
152 		*polarity = GPIO_ACTIVE_LOW;
153 		break;
154 	case INT3472_GPIO_TYPE_POWERDOWN:
155 		*func = "powerdown";
156 		*polarity = GPIO_ACTIVE_LOW;
157 		break;
158 	case INT3472_GPIO_TYPE_CLK_ENABLE:
159 		*func = "clk-enable";
160 		*polarity = GPIO_ACTIVE_HIGH;
161 		break;
162 	case INT3472_GPIO_TYPE_PRIVACY_LED:
163 		*func = "privacy-led";
164 		*polarity = GPIO_ACTIVE_HIGH;
165 		break;
166 	case INT3472_GPIO_TYPE_POWER_ENABLE:
167 		*func = "power-enable";
168 		*polarity = GPIO_ACTIVE_HIGH;
169 		break;
170 	default:
171 		*func = "unknown";
172 		*polarity = GPIO_ACTIVE_HIGH;
173 		break;
174 	}
175 }
176 
177 /**
178  * skl_int3472_handle_gpio_resources: Map PMIC resources to consuming sensor
179  * @ares: A pointer to a &struct acpi_resource
180  * @data: A pointer to a &struct int3472_discrete_device
181  *
182  * This function handles GPIO resources that are against an INT3472
183  * ACPI device, by checking the value of the corresponding _DSM entry.
184  * This will return a 32bit int, where the lowest byte represents the
185  * function of the GPIO pin:
186  *
187  * 0x00 Reset
188  * 0x01 Power down
189  * 0x0b Power enable
190  * 0x0c Clock enable
191  * 0x0d Privacy LED
192  *
193  * There are some known platform specific quirks where that does not quite
194  * hold up; for example where a pin with type 0x01 (Power down) is mapped to
195  * a sensor pin that performs a reset function or entries in _CRS and _DSM that
196  * do not actually correspond to a physical connection. These will be handled
197  * by the mapping sub-functions.
198  *
199  * GPIOs will either be mapped directly to the sensor device or else used
200  * to create clocks and regulators via the usual frameworks.
201  *
202  * Return:
203  * * 1		- To continue the loop
204  * * 0		- When all resources found are handled properly.
205  * * -EINVAL	- If the resource is not a GPIO IO resource
206  * * -ENODEV	- If the resource has no corresponding _DSM entry
207  * * -Other	- Errors propagated from one of the sub-functions.
208  */
209 static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares,
210 					     void *data)
211 {
212 	struct int3472_discrete_device *int3472 = data;
213 	struct acpi_resource_gpio *agpio;
214 	union acpi_object *obj;
215 	u8 active_value, type;
216 	const char *err_msg;
217 	const char *func;
218 	u32 polarity;
219 	int ret;
220 
221 	if (!acpi_gpio_get_io_resource(ares, &agpio))
222 		return 1;
223 
224 	/*
225 	 * ngpios + 2 because the index of this _DSM function is 1-based and
226 	 * the first function is just a count.
227 	 */
228 	obj = acpi_evaluate_dsm_typed(int3472->adev->handle,
229 				      &int3472_gpio_guid, 0x00,
230 				      int3472->ngpios + 2,
231 				      NULL, ACPI_TYPE_INTEGER);
232 
233 	if (!obj) {
234 		dev_warn(int3472->dev, "No _DSM entry for GPIO pin %u\n",
235 			 agpio->pin_table[0]);
236 		return 1;
237 	}
238 
239 	type = obj->integer.value & 0xff;
240 
241 	int3472_get_func_and_polarity(type, &func, &polarity);
242 
243 	/* If bits 31-24 of the _DSM entry are all 0 then the signal is inverted */
244 	active_value = obj->integer.value >> 24;
245 	if (!active_value)
246 		polarity ^= GPIO_ACTIVE_LOW;
247 
248 	dev_dbg(int3472->dev, "%s %s pin %d active-%s\n", func,
249 		agpio->resource_source.string_ptr, agpio->pin_table[0],
250 		(polarity == GPIO_ACTIVE_HIGH) ? "high" : "low");
251 
252 	switch (type) {
253 	case INT3472_GPIO_TYPE_RESET:
254 	case INT3472_GPIO_TYPE_POWERDOWN:
255 		ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, func, polarity);
256 		if (ret)
257 			err_msg = "Failed to map GPIO pin to sensor\n";
258 
259 		break;
260 	case INT3472_GPIO_TYPE_CLK_ENABLE:
261 		ret = skl_int3472_register_clock(int3472, agpio, polarity);
262 		if (ret)
263 			err_msg = "Failed to register clock\n";
264 
265 		break;
266 	case INT3472_GPIO_TYPE_PRIVACY_LED:
267 		ret = skl_int3472_register_pled(int3472, agpio, polarity);
268 		if (ret)
269 			err_msg = "Failed to register LED\n";
270 
271 		break;
272 	case INT3472_GPIO_TYPE_POWER_ENABLE:
273 		ret = skl_int3472_register_regulator(int3472, agpio);
274 		if (ret)
275 			err_msg = "Failed to map regulator to sensor\n";
276 
277 		break;
278 	default:
279 		dev_warn(int3472->dev,
280 			 "GPIO type 0x%02x unknown; the sensor may not work\n",
281 			 type);
282 		ret = 1;
283 		break;
284 	}
285 
286 	int3472->ngpios++;
287 	ACPI_FREE(obj);
288 
289 	if (ret < 0)
290 		return dev_err_probe(int3472->dev, ret, err_msg);
291 
292 	return ret;
293 }
294 
295 static int skl_int3472_parse_crs(struct int3472_discrete_device *int3472)
296 {
297 	LIST_HEAD(resource_list);
298 	int ret;
299 
300 	/*
301 	 * No error check, because not having a sensor config is not necessarily
302 	 * a failure mode.
303 	 */
304 	int3472->sensor_config = skl_int3472_get_sensor_module_config(int3472);
305 
306 	ret = acpi_dev_get_resources(int3472->adev, &resource_list,
307 				     skl_int3472_handle_gpio_resources,
308 				     int3472);
309 	if (ret < 0)
310 		return ret;
311 
312 	acpi_dev_free_resource_list(&resource_list);
313 
314 	int3472->gpios.dev_id = int3472->sensor_name;
315 	gpiod_add_lookup_table(&int3472->gpios);
316 
317 	return 0;
318 }
319 
320 static void skl_int3472_discrete_remove(struct platform_device *pdev)
321 {
322 	struct int3472_discrete_device *int3472 = platform_get_drvdata(pdev);
323 
324 	gpiod_remove_lookup_table(&int3472->gpios);
325 
326 	skl_int3472_unregister_clock(int3472);
327 	skl_int3472_unregister_pled(int3472);
328 	skl_int3472_unregister_regulator(int3472);
329 }
330 
331 static int skl_int3472_discrete_probe(struct platform_device *pdev)
332 {
333 	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
334 	struct int3472_discrete_device *int3472;
335 	struct int3472_cldb cldb;
336 	int ret;
337 
338 	ret = skl_int3472_fill_cldb(adev, &cldb);
339 	if (ret) {
340 		dev_err(&pdev->dev, "Couldn't fill CLDB structure\n");
341 		return ret;
342 	}
343 
344 	if (cldb.control_logic_type != 1) {
345 		dev_err(&pdev->dev, "Unsupported control logic type %u\n",
346 			cldb.control_logic_type);
347 		return -EINVAL;
348 	}
349 
350 	/* Max num GPIOs we've seen plus a terminator */
351 	int3472 = devm_kzalloc(&pdev->dev, struct_size(int3472, gpios.table,
352 			       INT3472_MAX_SENSOR_GPIOS + 1), GFP_KERNEL);
353 	if (!int3472)
354 		return -ENOMEM;
355 
356 	int3472->adev = adev;
357 	int3472->dev = &pdev->dev;
358 	platform_set_drvdata(pdev, int3472);
359 
360 	ret = skl_int3472_get_sensor_adev_and_name(&pdev->dev, &int3472->sensor,
361 						   &int3472->sensor_name);
362 	if (ret)
363 		return ret;
364 
365 	/*
366 	 * Initialising this list means we can call gpiod_remove_lookup_table()
367 	 * in failure paths without issue.
368 	 */
369 	INIT_LIST_HEAD(&int3472->gpios.list);
370 
371 	ret = skl_int3472_parse_crs(int3472);
372 	if (ret) {
373 		skl_int3472_discrete_remove(pdev);
374 		return ret;
375 	}
376 
377 	acpi_dev_clear_dependencies(adev);
378 	return 0;
379 }
380 
381 static const struct acpi_device_id int3472_device_id[] = {
382 	{ "INT3472", 0 },
383 	{ }
384 };
385 MODULE_DEVICE_TABLE(acpi, int3472_device_id);
386 
387 static struct platform_driver int3472_discrete = {
388 	.driver = {
389 		.name = "int3472-discrete",
390 		.acpi_match_table = int3472_device_id,
391 	},
392 	.probe = skl_int3472_discrete_probe,
393 	.remove_new = skl_int3472_discrete_remove,
394 };
395 module_platform_driver(int3472_discrete);
396 
397 MODULE_DESCRIPTION("Intel SkyLake INT3472 ACPI Discrete Device Driver");
398 MODULE_AUTHOR("Daniel Scally <djrscally@gmail.com>");
399 MODULE_LICENSE("GPL v2");
400