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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 */
26static 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 */
35static 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
52static const struct int3472_gpio_function_remap ov2680_gpio_function_remaps[] = {
53 { "reset", NULL },
54 { "powerdown", "reset" },
55 { }
56};
57
58static 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
67static const struct int3472_sensor_config *
68skl_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
105static 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
116 if (int3472->n_sensor_gpios >= INT3472_MAX_SENSOR_GPIOS) {
117 dev_warn(int3472->dev, "Too many GPIOs mapped\n");
118 return -EINVAL;
119 }
120
121 sensor_config = int3472->sensor_config;
122 if (!IS_ERR(sensor_config) && sensor_config->function_maps) {
123 const struct int3472_gpio_function_remap *remap;
124
125 for (remap = sensor_config->function_maps; remap->documented; remap++) {
126 if (!strcmp(func, remap->documented)) {
127 func = remap->actual;
128 break;
129 }
130 }
131 }
132
133 /* Functions mapped to NULL should not be mapped to the sensor */
134 if (!func)
135 return 0;
136
137 status = acpi_get_handle(NULL, path, &handle);
138 if (ACPI_FAILURE(status))
139 return -EINVAL;
140
141 adev = acpi_fetch_acpi_dev(handle);
142 if (!adev)
143 return -ENODEV;
144
145 table_entry = &int3472->gpios.table[int3472->n_sensor_gpios];
146 table_entry->key = acpi_dev_name(adev);
147 table_entry->chip_hwnum = agpio->pin_table[0];
148 table_entry->con_id = func;
149 table_entry->idx = 0;
150 table_entry->flags = polarity;
151
152 int3472->n_sensor_gpios++;
153
154 return 0;
155}
156
157static int skl_int3472_map_gpio_to_clk(struct int3472_discrete_device *int3472,
158 struct acpi_resource_gpio *agpio, u8 type)
159{
160 char *path = agpio->resource_source.string_ptr;
161 u16 pin = agpio->pin_table[0];
162 struct gpio_desc *gpio;
163
164 switch (type) {
165 case INT3472_GPIO_TYPE_CLK_ENABLE:
166 gpio = acpi_get_and_request_gpiod(path, pin, "int3472,clk-enable");
167 if (IS_ERR(gpio))
168 return (PTR_ERR(gpio));
169
170 int3472->clock.ena_gpio = gpio;
171 /* Ensure the pin is in output mode and non-active state */
172 gpiod_direction_output(int3472->clock.ena_gpio, 0);
173 break;
174 case INT3472_GPIO_TYPE_PRIVACY_LED:
175 gpio = acpi_get_and_request_gpiod(path, pin, "int3472,privacy-led");
176 if (IS_ERR(gpio))
177 return (PTR_ERR(gpio));
178
179 int3472->clock.led_gpio = gpio;
180 /* Ensure the pin is in output mode and non-active state */
181 gpiod_direction_output(int3472->clock.led_gpio, 0);
182 break;
183 default:
184 dev_err(int3472->dev, "Invalid GPIO type 0x%02x for clock\n", type);
185 break;
186 }
187
188 return 0;
189}
190
191/**
192 * skl_int3472_handle_gpio_resources: Map PMIC resources to consuming sensor
193 * @ares: A pointer to a &struct acpi_resource
194 * @data: A pointer to a &struct int3472_discrete_device
195 *
196 * This function handles GPIO resources that are against an INT3472
197 * ACPI device, by checking the value of the corresponding _DSM entry.
198 * This will return a 32bit int, where the lowest byte represents the
199 * function of the GPIO pin:
200 *
201 * 0x00 Reset
202 * 0x01 Power down
203 * 0x0b Power enable
204 * 0x0c Clock enable
205 * 0x0d Privacy LED
206 *
207 * There are some known platform specific quirks where that does not quite
208 * hold up; for example where a pin with type 0x01 (Power down) is mapped to
209 * a sensor pin that performs a reset function or entries in _CRS and _DSM that
210 * do not actually correspond to a physical connection. These will be handled
211 * by the mapping sub-functions.
212 *
213 * GPIOs will either be mapped directly to the sensor device or else used
214 * to create clocks and regulators via the usual frameworks.
215 *
216 * Return:
217 * * 1 - To continue the loop
218 * * 0 - When all resources found are handled properly.
219 * * -EINVAL - If the resource is not a GPIO IO resource
220 * * -ENODEV - If the resource has no corresponding _DSM entry
221 * * -Other - Errors propagated from one of the sub-functions.
222 */
223static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares,
224 void *data)
225{
226 struct int3472_discrete_device *int3472 = data;
227 struct acpi_resource_gpio *agpio;
228 union acpi_object *obj;
229 const char *err_msg;
230 int ret;
231 u8 type;
232
233 if (!acpi_gpio_get_io_resource(ares, &agpio))
234 return 1;
235
236 /*
237 * ngpios + 2 because the index of this _DSM function is 1-based and
238 * the first function is just a count.
239 */
240 obj = acpi_evaluate_dsm_typed(int3472->adev->handle,
241 &int3472_gpio_guid, 0x00,
242 int3472->ngpios + 2,
243 NULL, ACPI_TYPE_INTEGER);
244
245 if (!obj) {
246 dev_warn(int3472->dev, "No _DSM entry for GPIO pin %u\n",
247 agpio->pin_table[0]);
248 return 1;
249 }
250
251 type = obj->integer.value & 0xff;
252
253 switch (type) {
254 case INT3472_GPIO_TYPE_RESET:
255 ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, "reset",
256 GPIO_ACTIVE_LOW);
257 if (ret)
258 err_msg = "Failed to map reset pin to sensor\n";
259
260 break;
261 case INT3472_GPIO_TYPE_POWERDOWN:
262 ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, "powerdown",
263 GPIO_ACTIVE_LOW);
264 if (ret)
265 err_msg = "Failed to map powerdown pin to sensor\n";
266
267 break;
268 case INT3472_GPIO_TYPE_CLK_ENABLE:
269 case INT3472_GPIO_TYPE_PRIVACY_LED:
270 ret = skl_int3472_map_gpio_to_clk(int3472, agpio, type);
271 if (ret)
272 err_msg = "Failed to map GPIO to clock\n";
273
274 break;
275 case INT3472_GPIO_TYPE_POWER_ENABLE:
276 ret = skl_int3472_register_regulator(int3472, agpio);
277 if (ret)
278 err_msg = "Failed to map regulator to sensor\n";
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
298static int skl_int3472_parse_crs(struct int3472_discrete_device *int3472)
299{
300 LIST_HEAD(resource_list);
301 int ret;
302
303 /*
304 * No error check, because not having a sensor config is not necessarily
305 * a failure mode.
306 */
307 int3472->sensor_config = skl_int3472_get_sensor_module_config(int3472);
308
309 ret = acpi_dev_get_resources(int3472->adev, &resource_list,
310 skl_int3472_handle_gpio_resources,
311 int3472);
312 if (ret < 0)
313 return ret;
314
315 acpi_dev_free_resource_list(&resource_list);
316
317 /*
318 * If we find no clock enable GPIO pin then the privacy LED won't work.
319 * We've never seen that situation, but it's possible. Warn the user so
320 * it's clear what's happened.
321 */
322 if (int3472->clock.ena_gpio) {
323 ret = skl_int3472_register_clock(int3472);
324 if (ret)
325 return ret;
326 } else {
327 if (int3472->clock.led_gpio)
328 dev_warn(int3472->dev,
329 "No clk GPIO. The privacy LED won't work\n");
330 }
331
332 int3472->gpios.dev_id = int3472->sensor_name;
333 gpiod_add_lookup_table(&int3472->gpios);
334
335 return 0;
336}
337
338static int skl_int3472_discrete_remove(struct platform_device *pdev)
339{
340 struct int3472_discrete_device *int3472 = platform_get_drvdata(pdev);
341
342 gpiod_remove_lookup_table(&int3472->gpios);
343
344 if (int3472->clock.cl)
345 skl_int3472_unregister_clock(int3472);
346
347 gpiod_put(int3472->clock.ena_gpio);
348 gpiod_put(int3472->clock.led_gpio);
349
350 skl_int3472_unregister_regulator(int3472);
351
352 return 0;
353}
354
355static int skl_int3472_discrete_probe(struct platform_device *pdev)
356{
357 struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
358 struct int3472_discrete_device *int3472;
359 struct int3472_cldb cldb;
360 int ret;
361
362 ret = skl_int3472_fill_cldb(adev, &cldb);
363 if (ret) {
364 dev_err(&pdev->dev, "Couldn't fill CLDB structure\n");
365 return ret;
366 }
367
368 if (cldb.control_logic_type != 1) {
369 dev_err(&pdev->dev, "Unsupported control logic type %u\n",
370 cldb.control_logic_type);
371 return -EINVAL;
372 }
373
374 /* Max num GPIOs we've seen plus a terminator */
375 int3472 = devm_kzalloc(&pdev->dev, struct_size(int3472, gpios.table,
376 INT3472_MAX_SENSOR_GPIOS + 1), GFP_KERNEL);
377 if (!int3472)
378 return -ENOMEM;
379
380 int3472->adev = adev;
381 int3472->dev = &pdev->dev;
382 platform_set_drvdata(pdev, int3472);
383
384 ret = skl_int3472_get_sensor_adev_and_name(&pdev->dev, &int3472->sensor,
385 &int3472->sensor_name);
386 if (ret)
387 return ret;
388
389 /*
390 * Initialising this list means we can call gpiod_remove_lookup_table()
391 * in failure paths without issue.
392 */
393 INIT_LIST_HEAD(&int3472->gpios.list);
394
395 ret = skl_int3472_parse_crs(int3472);
396 if (ret) {
397 skl_int3472_discrete_remove(pdev);
398 return ret;
399 }
400
401 acpi_dev_clear_dependencies(adev);
402 return 0;
403}
404
405static const struct acpi_device_id int3472_device_id[] = {
406 { "INT3472", 0 },
407 { }
408};
409MODULE_DEVICE_TABLE(acpi, int3472_device_id);
410
411static struct platform_driver int3472_discrete = {
412 .driver = {
413 .name = "int3472-discrete",
414 .acpi_match_table = int3472_device_id,
415 },
416 .probe = skl_int3472_discrete_probe,
417 .remove = skl_int3472_discrete_remove,
418};
419module_platform_driver(int3472_discrete);
420
421MODULE_DESCRIPTION("Intel SkyLake INT3472 ACPI Discrete Device Driver");
422MODULE_AUTHOR("Daniel Scally <djrscally@gmail.com>");
423MODULE_LICENSE("GPL v2");