xref: /linux/drivers/platform/x86/intel/int3472/discrete.c (revision 0e862838f290147ea9c16db852d8d494b552d38d)
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  
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  
157  static 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  		break;
172  	case INT3472_GPIO_TYPE_PRIVACY_LED:
173  		gpio = acpi_get_and_request_gpiod(path, pin, "int3472,privacy-led");
174  		if (IS_ERR(gpio))
175  			return (PTR_ERR(gpio));
176  
177  		int3472->clock.led_gpio = gpio;
178  		break;
179  	default:
180  		dev_err(int3472->dev, "Invalid GPIO type 0x%02x for clock\n", type);
181  		break;
182  	}
183  
184  	return 0;
185  }
186  
187  /**
188   * skl_int3472_handle_gpio_resources: Map PMIC resources to consuming sensor
189   * @ares: A pointer to a &struct acpi_resource
190   * @data: A pointer to a &struct int3472_discrete_device
191   *
192   * This function handles GPIO resources that are against an INT3472
193   * ACPI device, by checking the value of the corresponding _DSM entry.
194   * This will return a 32bit int, where the lowest byte represents the
195   * function of the GPIO pin:
196   *
197   * 0x00 Reset
198   * 0x01 Power down
199   * 0x0b Power enable
200   * 0x0c Clock enable
201   * 0x0d Privacy LED
202   *
203   * There are some known platform specific quirks where that does not quite
204   * hold up; for example where a pin with type 0x01 (Power down) is mapped to
205   * a sensor pin that performs a reset function or entries in _CRS and _DSM that
206   * do not actually correspond to a physical connection. These will be handled
207   * by the mapping sub-functions.
208   *
209   * GPIOs will either be mapped directly to the sensor device or else used
210   * to create clocks and regulators via the usual frameworks.
211   *
212   * Return:
213   * * 1		- To continue the loop
214   * * 0		- When all resources found are handled properly.
215   * * -EINVAL	- If the resource is not a GPIO IO resource
216   * * -ENODEV	- If the resource has no corresponding _DSM entry
217   * * -Other	- Errors propagated from one of the sub-functions.
218   */
219  static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares,
220  					     void *data)
221  {
222  	struct int3472_discrete_device *int3472 = data;
223  	struct acpi_resource_gpio *agpio;
224  	union acpi_object *obj;
225  	const char *err_msg;
226  	int ret;
227  	u8 type;
228  
229  	if (!acpi_gpio_get_io_resource(ares, &agpio))
230  		return 1;
231  
232  	/*
233  	 * ngpios + 2 because the index of this _DSM function is 1-based and
234  	 * the first function is just a count.
235  	 */
236  	obj = acpi_evaluate_dsm_typed(int3472->adev->handle,
237  				      &int3472_gpio_guid, 0x00,
238  				      int3472->ngpios + 2,
239  				      NULL, ACPI_TYPE_INTEGER);
240  
241  	if (!obj) {
242  		dev_warn(int3472->dev, "No _DSM entry for GPIO pin %u\n",
243  			 agpio->pin_table[0]);
244  		return 1;
245  	}
246  
247  	type = obj->integer.value & 0xff;
248  
249  	switch (type) {
250  	case INT3472_GPIO_TYPE_RESET:
251  		ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, "reset",
252  						     GPIO_ACTIVE_LOW);
253  		if (ret)
254  			err_msg = "Failed to map reset pin to sensor\n";
255  
256  		break;
257  	case INT3472_GPIO_TYPE_POWERDOWN:
258  		ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, "powerdown",
259  						     GPIO_ACTIVE_LOW);
260  		if (ret)
261  			err_msg = "Failed to map powerdown pin to sensor\n";
262  
263  		break;
264  	case INT3472_GPIO_TYPE_CLK_ENABLE:
265  	case INT3472_GPIO_TYPE_PRIVACY_LED:
266  		ret = skl_int3472_map_gpio_to_clk(int3472, agpio, type);
267  		if (ret)
268  			err_msg = "Failed to map GPIO to clock\n";
269  
270  		break;
271  	case INT3472_GPIO_TYPE_POWER_ENABLE:
272  		ret = skl_int3472_register_regulator(int3472, agpio);
273  		if (ret)
274  			err_msg = "Failed to map regulator to sensor\n";
275  
276  		break;
277  	default:
278  		dev_warn(int3472->dev,
279  			 "GPIO type 0x%02x unknown; the sensor may not work\n",
280  			 type);
281  		ret = 1;
282  		break;
283  	}
284  
285  	int3472->ngpios++;
286  	ACPI_FREE(obj);
287  
288  	if (ret < 0)
289  		return dev_err_probe(int3472->dev, ret, err_msg);
290  
291  	return ret;
292  }
293  
294  static int skl_int3472_parse_crs(struct int3472_discrete_device *int3472)
295  {
296  	LIST_HEAD(resource_list);
297  	int ret;
298  
299  	/*
300  	 * No error check, because not having a sensor config is not necessarily
301  	 * a failure mode.
302  	 */
303  	int3472->sensor_config = skl_int3472_get_sensor_module_config(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  	/*
314  	 * If we find no clock enable GPIO pin then the privacy LED won't work.
315  	 * We've never seen that situation, but it's possible. Warn the user so
316  	 * it's clear what's happened.
317  	 */
318  	if (int3472->clock.ena_gpio) {
319  		ret = skl_int3472_register_clock(int3472);
320  		if (ret)
321  			return ret;
322  	} else {
323  		if (int3472->clock.led_gpio)
324  			dev_warn(int3472->dev,
325  				 "No clk GPIO. The privacy LED won't work\n");
326  	}
327  
328  	int3472->gpios.dev_id = int3472->sensor_name;
329  	gpiod_add_lookup_table(&int3472->gpios);
330  
331  	return 0;
332  }
333  
334  static int skl_int3472_discrete_remove(struct platform_device *pdev);
335  
336  static int skl_int3472_discrete_probe(struct platform_device *pdev)
337  {
338  	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
339  	struct int3472_discrete_device *int3472;
340  	struct int3472_cldb cldb;
341  	int ret;
342  
343  	ret = skl_int3472_fill_cldb(adev, &cldb);
344  	if (ret) {
345  		dev_err(&pdev->dev, "Couldn't fill CLDB structure\n");
346  		return ret;
347  	}
348  
349  	if (cldb.control_logic_type != 1) {
350  		dev_err(&pdev->dev, "Unsupported control logic type %u\n",
351  			cldb.control_logic_type);
352  		return -EINVAL;
353  	}
354  
355  	/* Max num GPIOs we've seen plus a terminator */
356  	int3472 = devm_kzalloc(&pdev->dev, struct_size(int3472, gpios.table,
357  			       INT3472_MAX_SENSOR_GPIOS + 1), GFP_KERNEL);
358  	if (!int3472)
359  		return -ENOMEM;
360  
361  	int3472->adev = adev;
362  	int3472->dev = &pdev->dev;
363  	platform_set_drvdata(pdev, int3472);
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 int skl_int3472_discrete_remove(struct platform_device *pdev)
387  {
388  	struct int3472_discrete_device *int3472 = platform_get_drvdata(pdev);
389  
390  	gpiod_remove_lookup_table(&int3472->gpios);
391  
392  	if (int3472->clock.cl)
393  		skl_int3472_unregister_clock(int3472);
394  
395  	gpiod_put(int3472->clock.ena_gpio);
396  	gpiod_put(int3472->clock.led_gpio);
397  
398  	skl_int3472_unregister_regulator(int3472);
399  
400  	return 0;
401  }
402  
403  static const struct acpi_device_id int3472_device_id[] = {
404  	{ "INT3472", 0 },
405  	{ }
406  };
407  MODULE_DEVICE_TABLE(acpi, int3472_device_id);
408  
409  static struct platform_driver int3472_discrete = {
410  	.driver = {
411  		.name = "int3472-discrete",
412  		.acpi_match_table = int3472_device_id,
413  	},
414  	.probe = skl_int3472_discrete_probe,
415  	.remove = skl_int3472_discrete_remove,
416  };
417  module_platform_driver(int3472_discrete);
418  
419  MODULE_DESCRIPTION("Intel SkyLake INT3472 ACPI Discrete Device Driver");
420  MODULE_AUTHOR("Daniel Scally <djrscally@gmail.com>");
421  MODULE_LICENSE("GPL v2");
422