xref: /linux/drivers/platform/x86/intel/int3472/discrete.c (revision 3652117f854819a148ff0fbe4492587d3520b5e5)
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/uuid.h>
15 
16 #include "common.h"
17 
18 /*
19  * 79234640-9e10-4fea-a5c1-b5aa8b19756f
20  * This _DSM GUID returns information about the GPIO lines mapped to a
21  * discrete INT3472 device. Function number 1 returns a count of the GPIO
22  * lines that are mapped. Subsequent functions return 32 bit ints encoding
23  * information about the GPIO line, including its purpose.
24  */
25 static const guid_t int3472_gpio_guid =
26 	GUID_INIT(0x79234640, 0x9e10, 0x4fea,
27 		  0xa5, 0xc1, 0xb5, 0xaa, 0x8b, 0x19, 0x75, 0x6f);
28 
29 #define INT3472_GPIO_DSM_TYPE				GENMASK(7, 0)
30 #define INT3472_GPIO_DSM_PIN				GENMASK(15, 8)
31 #define INT3472_GPIO_DSM_SENSOR_ON_VAL			GENMASK(31, 24)
32 
33 /*
34  * 822ace8f-2814-4174-a56b-5f029fe079ee
35  * This _DSM GUID returns a string from the sensor device, which acts as a
36  * module identifier.
37  */
38 static const guid_t cio2_sensor_module_guid =
39 	GUID_INIT(0x822ace8f, 0x2814, 0x4174,
40 		  0xa5, 0x6b, 0x5f, 0x02, 0x9f, 0xe0, 0x79, 0xee);
41 
42 static void skl_int3472_log_sensor_module_name(struct int3472_discrete_device *int3472)
43 {
44 	union acpi_object *obj;
45 
46 	obj = acpi_evaluate_dsm_typed(int3472->sensor->handle,
47 				      &cio2_sensor_module_guid, 0x00,
48 				      0x01, NULL, ACPI_TYPE_STRING);
49 	if (obj) {
50 		dev_dbg(int3472->dev, "Sensor module id: '%s'\n", obj->string.pointer);
51 		ACPI_FREE(obj);
52 	}
53 }
54 
55 static int skl_int3472_fill_gpiod_lookup(struct gpiod_lookup *table_entry,
56 					 struct acpi_resource_gpio *agpio,
57 					 const char *func, u32 polarity)
58 {
59 	char *path = agpio->resource_source.string_ptr;
60 	struct acpi_device *adev;
61 	acpi_handle handle;
62 	acpi_status status;
63 
64 	status = acpi_get_handle(NULL, path, &handle);
65 	if (ACPI_FAILURE(status))
66 		return -EINVAL;
67 
68 	adev = acpi_fetch_acpi_dev(handle);
69 	if (!adev)
70 		return -ENODEV;
71 
72 	table_entry->key = acpi_dev_name(adev);
73 	table_entry->chip_hwnum = agpio->pin_table[0];
74 	table_entry->con_id = func;
75 	table_entry->idx = 0;
76 	table_entry->flags = polarity;
77 
78 	return 0;
79 }
80 
81 static int skl_int3472_map_gpio_to_sensor(struct int3472_discrete_device *int3472,
82 					  struct acpi_resource_gpio *agpio,
83 					  const char *func, u32 polarity)
84 {
85 	int ret;
86 
87 	if (int3472->n_sensor_gpios >= INT3472_MAX_SENSOR_GPIOS) {
88 		dev_warn(int3472->dev, "Too many GPIOs mapped\n");
89 		return -EINVAL;
90 	}
91 
92 	ret = skl_int3472_fill_gpiod_lookup(&int3472->gpios.table[int3472->n_sensor_gpios],
93 					    agpio, func, polarity);
94 	if (ret)
95 		return ret;
96 
97 	int3472->n_sensor_gpios++;
98 
99 	return 0;
100 }
101 
102 /* This should *really* only be used when there's no other way... */
103 static struct gpio_desc *
104 skl_int3472_gpiod_get_from_temp_lookup(struct int3472_discrete_device *int3472,
105 				       struct acpi_resource_gpio *agpio,
106 				       const char *func, u32 polarity)
107 {
108 	struct gpio_desc *desc;
109 	int ret;
110 
111 	struct gpiod_lookup_table *lookup __free(kfree) =
112 			kzalloc(struct_size(lookup, table, 2), GFP_KERNEL);
113 	if (!lookup)
114 		return ERR_PTR(-ENOMEM);
115 
116 	lookup->dev_id = dev_name(int3472->dev);
117 	ret = skl_int3472_fill_gpiod_lookup(&lookup->table[0], agpio, func, polarity);
118 	if (ret)
119 		return ERR_PTR(ret);
120 
121 	gpiod_add_lookup_table(lookup);
122 	desc = devm_gpiod_get(int3472->dev, func, GPIOD_OUT_LOW);
123 	gpiod_remove_lookup_table(lookup);
124 
125 	return desc;
126 }
127 
128 static void int3472_get_func_and_polarity(u8 type, const char **func, u32 *polarity)
129 {
130 	switch (type) {
131 	case INT3472_GPIO_TYPE_RESET:
132 		*func = "reset";
133 		*polarity = GPIO_ACTIVE_LOW;
134 		break;
135 	case INT3472_GPIO_TYPE_POWERDOWN:
136 		*func = "powerdown";
137 		*polarity = GPIO_ACTIVE_LOW;
138 		break;
139 	case INT3472_GPIO_TYPE_CLK_ENABLE:
140 		*func = "clk-enable";
141 		*polarity = GPIO_ACTIVE_HIGH;
142 		break;
143 	case INT3472_GPIO_TYPE_PRIVACY_LED:
144 		*func = "privacy-led";
145 		*polarity = GPIO_ACTIVE_HIGH;
146 		break;
147 	case INT3472_GPIO_TYPE_POWER_ENABLE:
148 		*func = "power-enable";
149 		*polarity = GPIO_ACTIVE_HIGH;
150 		break;
151 	default:
152 		*func = "unknown";
153 		*polarity = GPIO_ACTIVE_HIGH;
154 		break;
155 	}
156 }
157 
158 /**
159  * skl_int3472_handle_gpio_resources: Map PMIC resources to consuming sensor
160  * @ares: A pointer to a &struct acpi_resource
161  * @data: A pointer to a &struct int3472_discrete_device
162  *
163  * This function handles GPIO resources that are against an INT3472
164  * ACPI device, by checking the value of the corresponding _DSM entry.
165  * This will return a 32bit int, where the lowest byte represents the
166  * function of the GPIO pin:
167  *
168  * 0x00 Reset
169  * 0x01 Power down
170  * 0x0b Power enable
171  * 0x0c Clock enable
172  * 0x0d Privacy LED
173  *
174  * There are some known platform specific quirks where that does not quite
175  * hold up; for example where a pin with type 0x01 (Power down) is mapped to
176  * a sensor pin that performs a reset function or entries in _CRS and _DSM that
177  * do not actually correspond to a physical connection. These will be handled
178  * by the mapping sub-functions.
179  *
180  * GPIOs will either be mapped directly to the sensor device or else used
181  * to create clocks and regulators via the usual frameworks.
182  *
183  * Return:
184  * * 1		- To continue the loop
185  * * 0		- When all resources found are handled properly.
186  * * -EINVAL	- If the resource is not a GPIO IO resource
187  * * -ENODEV	- If the resource has no corresponding _DSM entry
188  * * -Other	- Errors propagated from one of the sub-functions.
189  */
190 static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares,
191 					     void *data)
192 {
193 	struct int3472_discrete_device *int3472 = data;
194 	struct acpi_resource_gpio *agpio;
195 	u8 active_value, pin, type;
196 	union acpi_object *obj;
197 	struct gpio_desc *gpio;
198 	const char *err_msg;
199 	const char *func;
200 	u32 polarity;
201 	int ret;
202 
203 	if (!acpi_gpio_get_io_resource(ares, &agpio))
204 		return 1;
205 
206 	/*
207 	 * ngpios + 2 because the index of this _DSM function is 1-based and
208 	 * the first function is just a count.
209 	 */
210 	obj = acpi_evaluate_dsm_typed(int3472->adev->handle,
211 				      &int3472_gpio_guid, 0x00,
212 				      int3472->ngpios + 2,
213 				      NULL, ACPI_TYPE_INTEGER);
214 
215 	if (!obj) {
216 		dev_warn(int3472->dev, "No _DSM entry for GPIO pin %u\n",
217 			 agpio->pin_table[0]);
218 		return 1;
219 	}
220 
221 	type = FIELD_GET(INT3472_GPIO_DSM_TYPE, obj->integer.value);
222 
223 	int3472_get_func_and_polarity(type, &func, &polarity);
224 
225 	pin = FIELD_GET(INT3472_GPIO_DSM_PIN, obj->integer.value);
226 	if (pin != agpio->pin_table[0])
227 		dev_warn(int3472->dev, "%s %s pin number mismatch _DSM %d resource %d\n",
228 			 func, agpio->resource_source.string_ptr, pin,
229 			 agpio->pin_table[0]);
230 
231 	active_value = FIELD_GET(INT3472_GPIO_DSM_SENSOR_ON_VAL, obj->integer.value);
232 	if (!active_value)
233 		polarity ^= GPIO_ACTIVE_LOW;
234 
235 	dev_dbg(int3472->dev, "%s %s pin %d active-%s\n", func,
236 		agpio->resource_source.string_ptr, agpio->pin_table[0],
237 		(polarity == GPIO_ACTIVE_HIGH) ? "high" : "low");
238 
239 	switch (type) {
240 	case INT3472_GPIO_TYPE_RESET:
241 	case INT3472_GPIO_TYPE_POWERDOWN:
242 		ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, func, polarity);
243 		if (ret)
244 			err_msg = "Failed to map GPIO pin to sensor\n";
245 
246 		break;
247 	case INT3472_GPIO_TYPE_CLK_ENABLE:
248 	case INT3472_GPIO_TYPE_PRIVACY_LED:
249 	case INT3472_GPIO_TYPE_POWER_ENABLE:
250 		gpio = skl_int3472_gpiod_get_from_temp_lookup(int3472, agpio, func, polarity);
251 		if (IS_ERR(gpio)) {
252 			ret = PTR_ERR(gpio);
253 			err_msg = "Failed to get GPIO\n";
254 			break;
255 		}
256 
257 		switch (type) {
258 		case INT3472_GPIO_TYPE_CLK_ENABLE:
259 			ret = skl_int3472_register_gpio_clock(int3472, gpio);
260 			if (ret)
261 				err_msg = "Failed to register clock\n";
262 
263 			break;
264 		case INT3472_GPIO_TYPE_PRIVACY_LED:
265 			ret = skl_int3472_register_pled(int3472, gpio);
266 			if (ret)
267 				err_msg = "Failed to register LED\n";
268 
269 			break;
270 		case INT3472_GPIO_TYPE_POWER_ENABLE:
271 			ret = skl_int3472_register_regulator(int3472, gpio);
272 			if (ret)
273 				err_msg = "Failed to map regulator to sensor\n";
274 
275 			break;
276 		default: /* Never reached */
277 			ret = -EINVAL;
278 			break;
279 		}
280 		break;
281 	default:
282 		dev_warn(int3472->dev,
283 			 "GPIO type 0x%02x unknown; the sensor may not work\n",
284 			 type);
285 		ret = 1;
286 		break;
287 	}
288 
289 	int3472->ngpios++;
290 	ACPI_FREE(obj);
291 
292 	if (ret < 0)
293 		return dev_err_probe(int3472->dev, ret, err_msg);
294 
295 	return ret;
296 }
297 
298 static int skl_int3472_parse_crs(struct int3472_discrete_device *int3472)
299 {
300 	LIST_HEAD(resource_list);
301 	int ret;
302 
303 	skl_int3472_log_sensor_module_name(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 	/* Register _DSM based clock (no-op if a GPIO clock was already registered) */
314 	ret = skl_int3472_register_dsm_clock(int3472);
315 	if (ret < 0)
316 		return ret;
317 
318 	int3472->gpios.dev_id = int3472->sensor_name;
319 	gpiod_add_lookup_table(&int3472->gpios);
320 
321 	return 0;
322 }
323 
324 static void skl_int3472_discrete_remove(struct platform_device *pdev)
325 {
326 	struct int3472_discrete_device *int3472 = platform_get_drvdata(pdev);
327 
328 	gpiod_remove_lookup_table(&int3472->gpios);
329 
330 	skl_int3472_unregister_clock(int3472);
331 	skl_int3472_unregister_pled(int3472);
332 	skl_int3472_unregister_regulator(int3472);
333 }
334 
335 static int skl_int3472_discrete_probe(struct platform_device *pdev)
336 {
337 	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
338 	struct int3472_discrete_device *int3472;
339 	struct int3472_cldb cldb;
340 	int ret;
341 
342 	ret = skl_int3472_fill_cldb(adev, &cldb);
343 	if (ret) {
344 		dev_err(&pdev->dev, "Couldn't fill CLDB structure\n");
345 		return ret;
346 	}
347 
348 	if (cldb.control_logic_type != 1) {
349 		dev_err(&pdev->dev, "Unsupported control logic type %u\n",
350 			cldb.control_logic_type);
351 		return -EINVAL;
352 	}
353 
354 	/* Max num GPIOs we've seen plus a terminator */
355 	int3472 = devm_kzalloc(&pdev->dev, struct_size(int3472, gpios.table,
356 			       INT3472_MAX_SENSOR_GPIOS + 1), GFP_KERNEL);
357 	if (!int3472)
358 		return -ENOMEM;
359 
360 	int3472->adev = adev;
361 	int3472->dev = &pdev->dev;
362 	platform_set_drvdata(pdev, int3472);
363 	int3472->clock.imgclk_index = cldb.clock_source;
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 const struct acpi_device_id int3472_device_id[] = {
387 	{ "INT3472", 0 },
388 	{ }
389 };
390 MODULE_DEVICE_TABLE(acpi, int3472_device_id);
391 
392 static struct platform_driver int3472_discrete = {
393 	.driver = {
394 		.name = "int3472-discrete",
395 		.acpi_match_table = int3472_device_id,
396 	},
397 	.probe = skl_int3472_discrete_probe,
398 	.remove_new = skl_int3472_discrete_remove,
399 };
400 module_platform_driver(int3472_discrete);
401 
402 MODULE_DESCRIPTION("Intel SkyLake INT3472 ACPI Discrete Device Driver");
403 MODULE_AUTHOR("Daniel Scally <djrscally@gmail.com>");
404 MODULE_LICENSE("GPL v2");
405