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 	int ret;
116 
117 	if (int3472->n_sensor_gpios >= INT3472_MAX_SENSOR_GPIOS) {
118 		dev_warn(int3472->dev, "Too many GPIOs mapped\n");
119 		return -EINVAL;
120 	}
121 
122 	sensor_config = int3472->sensor_config;
123 	if (!IS_ERR(sensor_config) && sensor_config->function_maps) {
124 		const struct int3472_gpio_function_remap *remap;
125 
126 		for (remap = sensor_config->function_maps; remap->documented; remap++) {
127 			if (!strcmp(func, remap->documented)) {
128 				func = remap->actual;
129 				break;
130 			}
131 		}
132 	}
133 
134 	/* Functions mapped to NULL should not be mapped to the sensor */
135 	if (!func)
136 		return 0;
137 
138 	status = acpi_get_handle(NULL, path, &handle);
139 	if (ACPI_FAILURE(status))
140 		return -EINVAL;
141 
142 	ret = acpi_bus_get_device(handle, &adev);
143 	if (ret)
144 		return -ENODEV;
145 
146 	table_entry = &int3472->gpios.table[int3472->n_sensor_gpios];
147 	table_entry->key = acpi_dev_name(adev);
148 	table_entry->chip_hwnum = agpio->pin_table[0];
149 	table_entry->con_id = func;
150 	table_entry->idx = 0;
151 	table_entry->flags = polarity;
152 
153 	int3472->n_sensor_gpios++;
154 
155 	return 0;
156 }
157 
158 static int skl_int3472_map_gpio_to_clk(struct int3472_discrete_device *int3472,
159 				       struct acpi_resource_gpio *agpio, u8 type)
160 {
161 	char *path = agpio->resource_source.string_ptr;
162 	u16 pin = agpio->pin_table[0];
163 	struct gpio_desc *gpio;
164 
165 	switch (type) {
166 	case INT3472_GPIO_TYPE_CLK_ENABLE:
167 		gpio = acpi_get_and_request_gpiod(path, pin, "int3472,clk-enable");
168 		if (IS_ERR(gpio))
169 			return (PTR_ERR(gpio));
170 
171 		int3472->clock.ena_gpio = gpio;
172 		break;
173 	case INT3472_GPIO_TYPE_PRIVACY_LED:
174 		gpio = acpi_get_and_request_gpiod(path, pin, "int3472,privacy-led");
175 		if (IS_ERR(gpio))
176 			return (PTR_ERR(gpio));
177 
178 		int3472->clock.led_gpio = gpio;
179 		break;
180 	default:
181 		dev_err(int3472->dev, "Invalid GPIO type 0x%02x for clock\n", type);
182 		break;
183 	}
184 
185 	return 0;
186 }
187 
188 /**
189  * skl_int3472_handle_gpio_resources: Map PMIC resources to consuming sensor
190  * @ares: A pointer to a &struct acpi_resource
191  * @data: A pointer to a &struct int3472_discrete_device
192  *
193  * This function handles GPIO resources that are against an INT3472
194  * ACPI device, by checking the value of the corresponding _DSM entry.
195  * This will return a 32bit int, where the lowest byte represents the
196  * function of the GPIO pin:
197  *
198  * 0x00 Reset
199  * 0x01 Power down
200  * 0x0b Power enable
201  * 0x0c Clock enable
202  * 0x0d Privacy LED
203  *
204  * There are some known platform specific quirks where that does not quite
205  * hold up; for example where a pin with type 0x01 (Power down) is mapped to
206  * a sensor pin that performs a reset function or entries in _CRS and _DSM that
207  * do not actually correspond to a physical connection. These will be handled
208  * by the mapping sub-functions.
209  *
210  * GPIOs will either be mapped directly to the sensor device or else used
211  * to create clocks and regulators via the usual frameworks.
212  *
213  * Return:
214  * * 1		- To continue the loop
215  * * 0		- When all resources found are handled properly.
216  * * -EINVAL	- If the resource is not a GPIO IO resource
217  * * -ENODEV	- If the resource has no corresponding _DSM entry
218  * * -Other	- Errors propagated from one of the sub-functions.
219  */
220 static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares,
221 					     void *data)
222 {
223 	struct int3472_discrete_device *int3472 = data;
224 	struct acpi_resource_gpio *agpio;
225 	union acpi_object *obj;
226 	const char *err_msg;
227 	int ret;
228 	u8 type;
229 
230 	if (!acpi_gpio_get_io_resource(ares, &agpio))
231 		return 1;
232 
233 	/*
234 	 * ngpios + 2 because the index of this _DSM function is 1-based and
235 	 * the first function is just a count.
236 	 */
237 	obj = acpi_evaluate_dsm_typed(int3472->adev->handle,
238 				      &int3472_gpio_guid, 0x00,
239 				      int3472->ngpios + 2,
240 				      NULL, ACPI_TYPE_INTEGER);
241 
242 	if (!obj) {
243 		dev_warn(int3472->dev, "No _DSM entry for GPIO pin %u\n",
244 			 agpio->pin_table[0]);
245 		return 1;
246 	}
247 
248 	type = obj->integer.value & 0xff;
249 
250 	switch (type) {
251 	case INT3472_GPIO_TYPE_RESET:
252 		ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, "reset",
253 						     GPIO_ACTIVE_LOW);
254 		if (ret)
255 			err_msg = "Failed to map reset pin to sensor\n";
256 
257 		break;
258 	case INT3472_GPIO_TYPE_POWERDOWN:
259 		ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, "powerdown",
260 						     GPIO_ACTIVE_LOW);
261 		if (ret)
262 			err_msg = "Failed to map powerdown pin to sensor\n";
263 
264 		break;
265 	case INT3472_GPIO_TYPE_CLK_ENABLE:
266 	case INT3472_GPIO_TYPE_PRIVACY_LED:
267 		ret = skl_int3472_map_gpio_to_clk(int3472, agpio, type);
268 		if (ret)
269 			err_msg = "Failed to map GPIO to clock\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 	/*
315 	 * If we find no clock enable GPIO pin then the privacy LED won't work.
316 	 * We've never seen that situation, but it's possible. Warn the user so
317 	 * it's clear what's happened.
318 	 */
319 	if (int3472->clock.ena_gpio) {
320 		ret = skl_int3472_register_clock(int3472);
321 		if (ret)
322 			return ret;
323 	} else {
324 		if (int3472->clock.led_gpio)
325 			dev_warn(int3472->dev,
326 				 "No clk GPIO. The privacy LED won't work\n");
327 	}
328 
329 	int3472->gpios.dev_id = int3472->sensor_name;
330 	gpiod_add_lookup_table(&int3472->gpios);
331 
332 	return 0;
333 }
334 
335 static int skl_int3472_discrete_remove(struct platform_device *pdev);
336 
337 static int skl_int3472_discrete_probe(struct platform_device *pdev)
338 {
339 	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
340 	struct int3472_discrete_device *int3472;
341 	struct int3472_cldb cldb;
342 	int ret;
343 
344 	ret = skl_int3472_fill_cldb(adev, &cldb);
345 	if (ret) {
346 		dev_err(&pdev->dev, "Couldn't fill CLDB structure\n");
347 		return ret;
348 	}
349 
350 	if (cldb.control_logic_type != 1) {
351 		dev_err(&pdev->dev, "Unsupported control logic type %u\n",
352 			cldb.control_logic_type);
353 		return -EINVAL;
354 	}
355 
356 	/* Max num GPIOs we've seen plus a terminator */
357 	int3472 = devm_kzalloc(&pdev->dev, struct_size(int3472, gpios.table,
358 			       INT3472_MAX_SENSOR_GPIOS + 1), GFP_KERNEL);
359 	if (!int3472)
360 		return -ENOMEM;
361 
362 	int3472->adev = adev;
363 	int3472->dev = &pdev->dev;
364 	platform_set_drvdata(pdev, int3472);
365 
366 	ret = skl_int3472_get_sensor_adev_and_name(&pdev->dev, &int3472->sensor,
367 						   &int3472->sensor_name);
368 	if (ret)
369 		return ret;
370 
371 	/*
372 	 * Initialising this list means we can call gpiod_remove_lookup_table()
373 	 * in failure paths without issue.
374 	 */
375 	INIT_LIST_HEAD(&int3472->gpios.list);
376 
377 	ret = skl_int3472_parse_crs(int3472);
378 	if (ret) {
379 		skl_int3472_discrete_remove(pdev);
380 		return ret;
381 	}
382 
383 	acpi_dev_clear_dependencies(adev);
384 	return 0;
385 }
386 
387 static int skl_int3472_discrete_remove(struct platform_device *pdev)
388 {
389 	struct int3472_discrete_device *int3472 = platform_get_drvdata(pdev);
390 
391 	gpiod_remove_lookup_table(&int3472->gpios);
392 
393 	if (int3472->clock.cl)
394 		skl_int3472_unregister_clock(int3472);
395 
396 	gpiod_put(int3472->clock.ena_gpio);
397 	gpiod_put(int3472->clock.led_gpio);
398 
399 	skl_int3472_unregister_regulator(int3472);
400 
401 	return 0;
402 }
403 
404 static const struct acpi_device_id int3472_device_id[] = {
405 	{ "INT3472", 0 },
406 	{ }
407 };
408 MODULE_DEVICE_TABLE(acpi, int3472_device_id);
409 
410 static struct platform_driver int3472_discrete = {
411 	.driver = {
412 		.name = "int3472-discrete",
413 		.acpi_match_table = int3472_device_id,
414 	},
415 	.probe = skl_int3472_discrete_probe,
416 	.remove = skl_int3472_discrete_remove,
417 };
418 module_platform_driver(int3472_discrete);
419 
420 MODULE_DESCRIPTION("Intel SkyLake INT3472 ACPI Discrete Device Driver");
421 MODULE_AUTHOR("Daniel Scally <djrscally@gmail.com>");
422 MODULE_LICENSE("GPL v2");
423