xref: /linux/drivers/platform/x86/intel/int3472/discrete.c (revision 84bbfe6b6435658132df2880258d34babe46d3e0)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Author: Dan Scally <djrscally@gmail.com> */
3 
4 #include <linux/acpi.h>
5 #include <linux/bitfield.h>
6 #include <linux/device.h>
7 #include <linux/gpio/consumer.h>
8 #include <linux/gpio/machine.h>
9 #include <linux/i2c.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/overflow.h>
13 #include <linux/platform_device.h>
14 #include <linux/string_choices.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 #define INT3472_GPIO_DSM_TYPE				GENMASK(7, 0)
31 #define INT3472_GPIO_DSM_PIN				GENMASK(15, 8)
32 #define INT3472_GPIO_DSM_SENSOR_ON_VAL			GENMASK(31, 24)
33 
34 /*
35  * 822ace8f-2814-4174-a56b-5f029fe079ee
36  * This _DSM GUID returns a string from the sensor device, which acts as a
37  * module identifier.
38  */
39 static const guid_t cio2_sensor_module_guid =
40 	GUID_INIT(0x822ace8f, 0x2814, 0x4174,
41 		  0xa5, 0x6b, 0x5f, 0x02, 0x9f, 0xe0, 0x79, 0xee);
42 
43 static void skl_int3472_log_sensor_module_name(struct int3472_discrete_device *int3472)
44 {
45 	union acpi_object *obj;
46 
47 	obj = acpi_evaluate_dsm_typed(int3472->sensor->handle,
48 				      &cio2_sensor_module_guid, 0x00,
49 				      0x01, NULL, ACPI_TYPE_STRING);
50 	if (obj) {
51 		dev_dbg(int3472->dev, "Sensor module id: '%s'\n", obj->string.pointer);
52 		ACPI_FREE(obj);
53 	}
54 }
55 
56 static int skl_int3472_fill_gpiod_lookup(struct gpiod_lookup *table_entry,
57 					 struct acpi_resource_gpio *agpio,
58 					 const char *func, u32 polarity)
59 {
60 	char *path = agpio->resource_source.string_ptr;
61 	struct acpi_device *adev;
62 	acpi_handle handle;
63 	acpi_status status;
64 
65 	status = acpi_get_handle(NULL, path, &handle);
66 	if (ACPI_FAILURE(status))
67 		return -EINVAL;
68 
69 	adev = acpi_fetch_acpi_dev(handle);
70 	if (!adev)
71 		return -ENODEV;
72 
73 	*table_entry = GPIO_LOOKUP(acpi_dev_name(adev), agpio->pin_table[0], func, polarity);
74 
75 	return 0;
76 }
77 
78 static int skl_int3472_map_gpio_to_sensor(struct int3472_discrete_device *int3472,
79 					  struct acpi_resource_gpio *agpio,
80 					  const char *func, u32 polarity)
81 {
82 	int ret;
83 
84 	if (int3472->n_sensor_gpios >= INT3472_MAX_SENSOR_GPIOS) {
85 		dev_warn(int3472->dev, "Too many GPIOs mapped\n");
86 		return -EINVAL;
87 	}
88 
89 	ret = skl_int3472_fill_gpiod_lookup(&int3472->gpios.table[int3472->n_sensor_gpios],
90 					    agpio, func, polarity);
91 	if (ret)
92 		return ret;
93 
94 	int3472->n_sensor_gpios++;
95 
96 	return 0;
97 }
98 
99 /* This should *really* only be used when there's no other way... */
100 static struct gpio_desc *
101 skl_int3472_gpiod_get_from_temp_lookup(struct int3472_discrete_device *int3472,
102 				       struct acpi_resource_gpio *agpio,
103 				       const char *func, u32 polarity)
104 {
105 	struct gpio_desc *desc;
106 	int ret;
107 
108 	struct gpiod_lookup_table *lookup __free(kfree) =
109 			kzalloc(struct_size(lookup, table, 2), GFP_KERNEL);
110 	if (!lookup)
111 		return ERR_PTR(-ENOMEM);
112 
113 	lookup->dev_id = dev_name(int3472->dev);
114 	ret = skl_int3472_fill_gpiod_lookup(&lookup->table[0], agpio, func, polarity);
115 	if (ret)
116 		return ERR_PTR(ret);
117 
118 	gpiod_add_lookup_table(lookup);
119 	desc = devm_gpiod_get(int3472->dev, func, GPIOD_OUT_LOW);
120 	gpiod_remove_lookup_table(lookup);
121 
122 	return desc;
123 }
124 
125 static void int3472_get_func_and_polarity(u8 type, const char **func, u32 *polarity)
126 {
127 	switch (type) {
128 	case INT3472_GPIO_TYPE_RESET:
129 		*func = "reset";
130 		*polarity = GPIO_ACTIVE_LOW;
131 		break;
132 	case INT3472_GPIO_TYPE_POWERDOWN:
133 		*func = "powerdown";
134 		*polarity = GPIO_ACTIVE_LOW;
135 		break;
136 	case INT3472_GPIO_TYPE_CLK_ENABLE:
137 		*func = "clk-enable";
138 		*polarity = GPIO_ACTIVE_HIGH;
139 		break;
140 	case INT3472_GPIO_TYPE_PRIVACY_LED:
141 		*func = "privacy-led";
142 		*polarity = GPIO_ACTIVE_HIGH;
143 		break;
144 	case INT3472_GPIO_TYPE_POWER_ENABLE:
145 		*func = "power-enable";
146 		*polarity = GPIO_ACTIVE_HIGH;
147 		break;
148 	default:
149 		*func = "unknown";
150 		*polarity = GPIO_ACTIVE_HIGH;
151 		break;
152 	}
153 }
154 
155 /**
156  * skl_int3472_handle_gpio_resources: Map PMIC resources to consuming sensor
157  * @ares: A pointer to a &struct acpi_resource
158  * @data: A pointer to a &struct int3472_discrete_device
159  *
160  * This function handles GPIO resources that are against an INT3472
161  * ACPI device, by checking the value of the corresponding _DSM entry.
162  * This will return a 32bit int, where the lowest byte represents the
163  * function of the GPIO pin:
164  *
165  * 0x00 Reset
166  * 0x01 Power down
167  * 0x0b Power enable
168  * 0x0c Clock enable
169  * 0x0d Privacy LED
170  *
171  * There are some known platform specific quirks where that does not quite
172  * hold up; for example where a pin with type 0x01 (Power down) is mapped to
173  * a sensor pin that performs a reset function or entries in _CRS and _DSM that
174  * do not actually correspond to a physical connection. These will be handled
175  * by the mapping sub-functions.
176  *
177  * GPIOs will either be mapped directly to the sensor device or else used
178  * to create clocks and regulators via the usual frameworks.
179  *
180  * Return:
181  * * 1		- To continue the loop
182  * * 0		- When all resources found are handled properly.
183  * * -EINVAL	- If the resource is not a GPIO IO resource
184  * * -ENODEV	- If the resource has no corresponding _DSM entry
185  * * -Other	- Errors propagated from one of the sub-functions.
186  */
187 static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares,
188 					     void *data)
189 {
190 	struct int3472_discrete_device *int3472 = data;
191 	struct acpi_resource_gpio *agpio;
192 	u8 active_value, pin, type;
193 	union acpi_object *obj;
194 	struct gpio_desc *gpio;
195 	const char *err_msg;
196 	const char *func;
197 	u32 polarity;
198 	int ret;
199 
200 	if (!acpi_gpio_get_io_resource(ares, &agpio))
201 		return 1;
202 
203 	/*
204 	 * ngpios + 2 because the index of this _DSM function is 1-based and
205 	 * the first function is just a count.
206 	 */
207 	obj = acpi_evaluate_dsm_typed(int3472->adev->handle,
208 				      &int3472_gpio_guid, 0x00,
209 				      int3472->ngpios + 2,
210 				      NULL, ACPI_TYPE_INTEGER);
211 
212 	if (!obj) {
213 		dev_warn(int3472->dev, "No _DSM entry for GPIO pin %u\n",
214 			 agpio->pin_table[0]);
215 		return 1;
216 	}
217 
218 	type = FIELD_GET(INT3472_GPIO_DSM_TYPE, obj->integer.value);
219 
220 	int3472_get_func_and_polarity(type, &func, &polarity);
221 
222 	pin = FIELD_GET(INT3472_GPIO_DSM_PIN, obj->integer.value);
223 	if (pin != agpio->pin_table[0])
224 		dev_warn(int3472->dev, "%s %s pin number mismatch _DSM %d resource %d\n",
225 			 func, agpio->resource_source.string_ptr, pin,
226 			 agpio->pin_table[0]);
227 
228 	active_value = FIELD_GET(INT3472_GPIO_DSM_SENSOR_ON_VAL, obj->integer.value);
229 	if (!active_value)
230 		polarity ^= GPIO_ACTIVE_LOW;
231 
232 	dev_dbg(int3472->dev, "%s %s pin %d active-%s\n", func,
233 		agpio->resource_source.string_ptr, agpio->pin_table[0],
234 		str_high_low(polarity == GPIO_ACTIVE_HIGH));
235 
236 	switch (type) {
237 	case INT3472_GPIO_TYPE_RESET:
238 	case INT3472_GPIO_TYPE_POWERDOWN:
239 		ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, func, polarity);
240 		if (ret)
241 			err_msg = "Failed to map GPIO pin to sensor\n";
242 
243 		break;
244 	case INT3472_GPIO_TYPE_CLK_ENABLE:
245 	case INT3472_GPIO_TYPE_PRIVACY_LED:
246 	case INT3472_GPIO_TYPE_POWER_ENABLE:
247 		gpio = skl_int3472_gpiod_get_from_temp_lookup(int3472, agpio, func, polarity);
248 		if (IS_ERR(gpio)) {
249 			ret = PTR_ERR(gpio);
250 			err_msg = "Failed to get GPIO\n";
251 			break;
252 		}
253 
254 		switch (type) {
255 		case INT3472_GPIO_TYPE_CLK_ENABLE:
256 			ret = skl_int3472_register_gpio_clock(int3472, gpio);
257 			if (ret)
258 				err_msg = "Failed to register clock\n";
259 
260 			break;
261 		case INT3472_GPIO_TYPE_PRIVACY_LED:
262 			ret = skl_int3472_register_pled(int3472, gpio);
263 			if (ret)
264 				err_msg = "Failed to register LED\n";
265 
266 			break;
267 		case INT3472_GPIO_TYPE_POWER_ENABLE:
268 			ret = skl_int3472_register_regulator(int3472, gpio);
269 			if (ret)
270 				err_msg = "Failed to map regulator to sensor\n";
271 
272 			break;
273 		default: /* Never reached */
274 			ret = -EINVAL;
275 			break;
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 	skl_int3472_log_sensor_module_name(int3472);
301 
302 	ret = acpi_dev_get_resources(int3472->adev, &resource_list,
303 				     skl_int3472_handle_gpio_resources,
304 				     int3472);
305 	if (ret < 0)
306 		return ret;
307 
308 	acpi_dev_free_resource_list(&resource_list);
309 
310 	/* Register _DSM based clock (no-op if a GPIO clock was already registered) */
311 	ret = skl_int3472_register_dsm_clock(int3472);
312 	if (ret < 0)
313 		return ret;
314 
315 	int3472->gpios.dev_id = int3472->sensor_name;
316 	gpiod_add_lookup_table(&int3472->gpios);
317 
318 	return 0;
319 }
320 
321 static void skl_int3472_discrete_remove(struct platform_device *pdev)
322 {
323 	struct int3472_discrete_device *int3472 = platform_get_drvdata(pdev);
324 
325 	gpiod_remove_lookup_table(&int3472->gpios);
326 
327 	skl_int3472_unregister_clock(int3472);
328 	skl_int3472_unregister_pled(int3472);
329 	skl_int3472_unregister_regulator(int3472);
330 }
331 
332 static int skl_int3472_discrete_probe(struct platform_device *pdev)
333 {
334 	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
335 	struct int3472_discrete_device *int3472;
336 	struct int3472_cldb cldb;
337 	int ret;
338 
339 	ret = skl_int3472_fill_cldb(adev, &cldb);
340 	if (ret) {
341 		dev_err(&pdev->dev, "Couldn't fill CLDB structure\n");
342 		return ret;
343 	}
344 
345 	if (cldb.control_logic_type != 1) {
346 		dev_err(&pdev->dev, "Unsupported control logic type %u\n",
347 			cldb.control_logic_type);
348 		return -EINVAL;
349 	}
350 
351 	/* Max num GPIOs we've seen plus a terminator */
352 	int3472 = devm_kzalloc(&pdev->dev, struct_size(int3472, gpios.table,
353 			       INT3472_MAX_SENSOR_GPIOS + 1), GFP_KERNEL);
354 	if (!int3472)
355 		return -ENOMEM;
356 
357 	int3472->adev = adev;
358 	int3472->dev = &pdev->dev;
359 	platform_set_drvdata(pdev, int3472);
360 	int3472->clock.imgclk_index = cldb.clock_source;
361 
362 	ret = skl_int3472_get_sensor_adev_and_name(&pdev->dev, &int3472->sensor,
363 						   &int3472->sensor_name);
364 	if (ret)
365 		return ret;
366 
367 	/*
368 	 * Initialising this list means we can call gpiod_remove_lookup_table()
369 	 * in failure paths without issue.
370 	 */
371 	INIT_LIST_HEAD(&int3472->gpios.list);
372 
373 	ret = skl_int3472_parse_crs(int3472);
374 	if (ret) {
375 		skl_int3472_discrete_remove(pdev);
376 		return ret;
377 	}
378 
379 	acpi_dev_clear_dependencies(adev);
380 	return 0;
381 }
382 
383 static const struct acpi_device_id int3472_device_id[] = {
384 	{ "INT3472", 0 },
385 	{ }
386 };
387 MODULE_DEVICE_TABLE(acpi, int3472_device_id);
388 
389 static struct platform_driver int3472_discrete = {
390 	.driver = {
391 		.name = "int3472-discrete",
392 		.acpi_match_table = int3472_device_id,
393 	},
394 	.probe = skl_int3472_discrete_probe,
395 	.remove_new = skl_int3472_discrete_remove,
396 };
397 module_platform_driver(int3472_discrete);
398 
399 MODULE_DESCRIPTION("Intel SkyLake INT3472 ACPI Discrete Device Driver");
400 MODULE_AUTHOR("Daniel Scally <djrscally@gmail.com>");
401 MODULE_LICENSE("GPL v2");
402