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_map_gpio_to_sensor(struct int3472_discrete_device *int3472,
56 					  struct acpi_resource_gpio *agpio,
57 					  const char *func, u32 polarity)
58 {
59 	char *path = agpio->resource_source.string_ptr;
60 	struct gpiod_lookup *table_entry;
61 	struct acpi_device *adev;
62 	acpi_handle handle;
63 	acpi_status status;
64 
65 	if (int3472->n_sensor_gpios >= INT3472_MAX_SENSOR_GPIOS) {
66 		dev_warn(int3472->dev, "Too many GPIOs mapped\n");
67 		return -EINVAL;
68 	}
69 
70 	status = acpi_get_handle(NULL, path, &handle);
71 	if (ACPI_FAILURE(status))
72 		return -EINVAL;
73 
74 	adev = acpi_fetch_acpi_dev(handle);
75 	if (!adev)
76 		return -ENODEV;
77 
78 	table_entry = &int3472->gpios.table[int3472->n_sensor_gpios];
79 	table_entry->key = acpi_dev_name(adev);
80 	table_entry->chip_hwnum = agpio->pin_table[0];
81 	table_entry->con_id = func;
82 	table_entry->idx = 0;
83 	table_entry->flags = polarity;
84 
85 	int3472->n_sensor_gpios++;
86 
87 	return 0;
88 }
89 
90 static void int3472_get_func_and_polarity(u8 type, const char **func, u32 *polarity)
91 {
92 	switch (type) {
93 	case INT3472_GPIO_TYPE_RESET:
94 		*func = "reset";
95 		*polarity = GPIO_ACTIVE_LOW;
96 		break;
97 	case INT3472_GPIO_TYPE_POWERDOWN:
98 		*func = "powerdown";
99 		*polarity = GPIO_ACTIVE_LOW;
100 		break;
101 	case INT3472_GPIO_TYPE_CLK_ENABLE:
102 		*func = "clk-enable";
103 		*polarity = GPIO_ACTIVE_HIGH;
104 		break;
105 	case INT3472_GPIO_TYPE_PRIVACY_LED:
106 		*func = "privacy-led";
107 		*polarity = GPIO_ACTIVE_HIGH;
108 		break;
109 	case INT3472_GPIO_TYPE_POWER_ENABLE:
110 		*func = "power-enable";
111 		*polarity = GPIO_ACTIVE_HIGH;
112 		break;
113 	default:
114 		*func = "unknown";
115 		*polarity = GPIO_ACTIVE_HIGH;
116 		break;
117 	}
118 }
119 
120 /**
121  * skl_int3472_handle_gpio_resources: Map PMIC resources to consuming sensor
122  * @ares: A pointer to a &struct acpi_resource
123  * @data: A pointer to a &struct int3472_discrete_device
124  *
125  * This function handles GPIO resources that are against an INT3472
126  * ACPI device, by checking the value of the corresponding _DSM entry.
127  * This will return a 32bit int, where the lowest byte represents the
128  * function of the GPIO pin:
129  *
130  * 0x00 Reset
131  * 0x01 Power down
132  * 0x0b Power enable
133  * 0x0c Clock enable
134  * 0x0d Privacy LED
135  *
136  * There are some known platform specific quirks where that does not quite
137  * hold up; for example where a pin with type 0x01 (Power down) is mapped to
138  * a sensor pin that performs a reset function or entries in _CRS and _DSM that
139  * do not actually correspond to a physical connection. These will be handled
140  * by the mapping sub-functions.
141  *
142  * GPIOs will either be mapped directly to the sensor device or else used
143  * to create clocks and regulators via the usual frameworks.
144  *
145  * Return:
146  * * 1		- To continue the loop
147  * * 0		- When all resources found are handled properly.
148  * * -EINVAL	- If the resource is not a GPIO IO resource
149  * * -ENODEV	- If the resource has no corresponding _DSM entry
150  * * -Other	- Errors propagated from one of the sub-functions.
151  */
152 static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares,
153 					     void *data)
154 {
155 	struct int3472_discrete_device *int3472 = data;
156 	struct acpi_resource_gpio *agpio;
157 	u8 active_value, pin, type;
158 	union acpi_object *obj;
159 	const char *err_msg;
160 	const char *func;
161 	u32 polarity;
162 	int ret;
163 
164 	if (!acpi_gpio_get_io_resource(ares, &agpio))
165 		return 1;
166 
167 	/*
168 	 * ngpios + 2 because the index of this _DSM function is 1-based and
169 	 * the first function is just a count.
170 	 */
171 	obj = acpi_evaluate_dsm_typed(int3472->adev->handle,
172 				      &int3472_gpio_guid, 0x00,
173 				      int3472->ngpios + 2,
174 				      NULL, ACPI_TYPE_INTEGER);
175 
176 	if (!obj) {
177 		dev_warn(int3472->dev, "No _DSM entry for GPIO pin %u\n",
178 			 agpio->pin_table[0]);
179 		return 1;
180 	}
181 
182 	type = FIELD_GET(INT3472_GPIO_DSM_TYPE, obj->integer.value);
183 
184 	int3472_get_func_and_polarity(type, &func, &polarity);
185 
186 	pin = FIELD_GET(INT3472_GPIO_DSM_PIN, obj->integer.value);
187 	if (pin != agpio->pin_table[0])
188 		dev_warn(int3472->dev, "%s %s pin number mismatch _DSM %d resource %d\n",
189 			 func, agpio->resource_source.string_ptr, pin,
190 			 agpio->pin_table[0]);
191 
192 	active_value = FIELD_GET(INT3472_GPIO_DSM_SENSOR_ON_VAL, obj->integer.value);
193 	if (!active_value)
194 		polarity ^= GPIO_ACTIVE_LOW;
195 
196 	dev_dbg(int3472->dev, "%s %s pin %d active-%s\n", func,
197 		agpio->resource_source.string_ptr, agpio->pin_table[0],
198 		(polarity == GPIO_ACTIVE_HIGH) ? "high" : "low");
199 
200 	switch (type) {
201 	case INT3472_GPIO_TYPE_RESET:
202 	case INT3472_GPIO_TYPE_POWERDOWN:
203 		ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, func, polarity);
204 		if (ret)
205 			err_msg = "Failed to map GPIO pin to sensor\n";
206 
207 		break;
208 	case INT3472_GPIO_TYPE_CLK_ENABLE:
209 		ret = skl_int3472_register_gpio_clock(int3472, agpio, polarity);
210 		if (ret)
211 			err_msg = "Failed to register clock\n";
212 
213 		break;
214 	case INT3472_GPIO_TYPE_PRIVACY_LED:
215 		ret = skl_int3472_register_pled(int3472, agpio, polarity);
216 		if (ret)
217 			err_msg = "Failed to register LED\n";
218 
219 		break;
220 	case INT3472_GPIO_TYPE_POWER_ENABLE:
221 		ret = skl_int3472_register_regulator(int3472, agpio);
222 		if (ret)
223 			err_msg = "Failed to map regulator to sensor\n";
224 
225 		break;
226 	default:
227 		dev_warn(int3472->dev,
228 			 "GPIO type 0x%02x unknown; the sensor may not work\n",
229 			 type);
230 		ret = 1;
231 		break;
232 	}
233 
234 	int3472->ngpios++;
235 	ACPI_FREE(obj);
236 
237 	if (ret < 0)
238 		return dev_err_probe(int3472->dev, ret, err_msg);
239 
240 	return ret;
241 }
242 
243 static int skl_int3472_parse_crs(struct int3472_discrete_device *int3472)
244 {
245 	LIST_HEAD(resource_list);
246 	int ret;
247 
248 	skl_int3472_log_sensor_module_name(int3472);
249 
250 	ret = acpi_dev_get_resources(int3472->adev, &resource_list,
251 				     skl_int3472_handle_gpio_resources,
252 				     int3472);
253 	if (ret < 0)
254 		return ret;
255 
256 	acpi_dev_free_resource_list(&resource_list);
257 
258 	/* Register _DSM based clock (no-op if a GPIO clock was already registered) */
259 	ret = skl_int3472_register_dsm_clock(int3472);
260 	if (ret < 0)
261 		return ret;
262 
263 	int3472->gpios.dev_id = int3472->sensor_name;
264 	gpiod_add_lookup_table(&int3472->gpios);
265 
266 	return 0;
267 }
268 
269 static void skl_int3472_discrete_remove(struct platform_device *pdev)
270 {
271 	struct int3472_discrete_device *int3472 = platform_get_drvdata(pdev);
272 
273 	gpiod_remove_lookup_table(&int3472->gpios);
274 
275 	skl_int3472_unregister_clock(int3472);
276 	skl_int3472_unregister_pled(int3472);
277 	skl_int3472_unregister_regulator(int3472);
278 }
279 
280 static int skl_int3472_discrete_probe(struct platform_device *pdev)
281 {
282 	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
283 	struct int3472_discrete_device *int3472;
284 	struct int3472_cldb cldb;
285 	int ret;
286 
287 	ret = skl_int3472_fill_cldb(adev, &cldb);
288 	if (ret) {
289 		dev_err(&pdev->dev, "Couldn't fill CLDB structure\n");
290 		return ret;
291 	}
292 
293 	if (cldb.control_logic_type != 1) {
294 		dev_err(&pdev->dev, "Unsupported control logic type %u\n",
295 			cldb.control_logic_type);
296 		return -EINVAL;
297 	}
298 
299 	/* Max num GPIOs we've seen plus a terminator */
300 	int3472 = devm_kzalloc(&pdev->dev, struct_size(int3472, gpios.table,
301 			       INT3472_MAX_SENSOR_GPIOS + 1), GFP_KERNEL);
302 	if (!int3472)
303 		return -ENOMEM;
304 
305 	int3472->adev = adev;
306 	int3472->dev = &pdev->dev;
307 	platform_set_drvdata(pdev, int3472);
308 	int3472->clock.imgclk_index = cldb.clock_source;
309 
310 	ret = skl_int3472_get_sensor_adev_and_name(&pdev->dev, &int3472->sensor,
311 						   &int3472->sensor_name);
312 	if (ret)
313 		return ret;
314 
315 	/*
316 	 * Initialising this list means we can call gpiod_remove_lookup_table()
317 	 * in failure paths without issue.
318 	 */
319 	INIT_LIST_HEAD(&int3472->gpios.list);
320 
321 	ret = skl_int3472_parse_crs(int3472);
322 	if (ret) {
323 		skl_int3472_discrete_remove(pdev);
324 		return ret;
325 	}
326 
327 	acpi_dev_clear_dependencies(adev);
328 	return 0;
329 }
330 
331 static const struct acpi_device_id int3472_device_id[] = {
332 	{ "INT3472", 0 },
333 	{ }
334 };
335 MODULE_DEVICE_TABLE(acpi, int3472_device_id);
336 
337 static struct platform_driver int3472_discrete = {
338 	.driver = {
339 		.name = "int3472-discrete",
340 		.acpi_match_table = int3472_device_id,
341 	},
342 	.probe = skl_int3472_discrete_probe,
343 	.remove_new = skl_int3472_discrete_remove,
344 };
345 module_platform_driver(int3472_discrete);
346 
347 MODULE_DESCRIPTION("Intel SkyLake INT3472 ACPI Discrete Device Driver");
348 MODULE_AUTHOR("Daniel Scally <djrscally@gmail.com>");
349 MODULE_LICENSE("GPL v2");
350