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 "intel_skl_int3472_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	int ret;
116
117	if (int3472->n_sensor_gpios >= INT3472_MAX_SENSOR_GPIOS) {
118		dev_warn(int3472->dev, "Too many GPIOs mapped\n");
119		return -EINVAL;
120	}
121
122	sensor_config = int3472->sensor_config;
123	if (!IS_ERR(sensor_config) && sensor_config->function_maps) {
124		const struct int3472_gpio_function_remap *remap;
125
126		for (remap = sensor_config->function_maps; remap->documented; remap++) {
127			if (!strcmp(func, remap->documented)) {
128				func = remap->actual;
129				break;
130			}
131		}
132	}
133
134	/* Functions mapped to NULL should not be mapped to the sensor */
135	if (!func)
136		return 0;
137
138	status = acpi_get_handle(NULL, path, &handle);
139	if (ACPI_FAILURE(status))
140		return -EINVAL;
141
142	ret = acpi_bus_get_device(handle, &adev);
143	if (ret)
144		return -ENODEV;
145
146	table_entry = &int3472->gpios.table[int3472->n_sensor_gpios];
147	table_entry->key = acpi_dev_name(adev);
148	table_entry->chip_hwnum = agpio->pin_table[0];
149	table_entry->con_id = func;
150	table_entry->idx = 0;
151	table_entry->flags = polarity;
152
153	int3472->n_sensor_gpios++;
154
155	return 0;
156}
157
158static int skl_int3472_map_gpio_to_clk(struct int3472_discrete_device *int3472,
159				       struct acpi_resource_gpio *agpio, u8 type)
160{
161	char *path = agpio->resource_source.string_ptr;
162	u16 pin = agpio->pin_table[0];
163	struct gpio_desc *gpio;
164
165	switch (type) {
166	case INT3472_GPIO_TYPE_CLK_ENABLE:
167		gpio = acpi_get_and_request_gpiod(path, pin, "int3472,clk-enable");
168		if (IS_ERR(gpio))
169			return (PTR_ERR(gpio));
170
171		int3472->clock.ena_gpio = gpio;
172		break;
173	case INT3472_GPIO_TYPE_PRIVACY_LED:
174		gpio = acpi_get_and_request_gpiod(path, pin, "int3472,privacy-led");
175		if (IS_ERR(gpio))
176			return (PTR_ERR(gpio));
177
178		int3472->clock.led_gpio = gpio;
179		break;
180	default:
181		dev_err(int3472->dev, "Invalid GPIO type 0x%02x for clock\n", type);
182		break;
183	}
184
185	return 0;
186}
187
188/**
189 * skl_int3472_handle_gpio_resources: Map PMIC resources to consuming sensor
190 * @ares: A pointer to a &struct acpi_resource
191 * @data: A pointer to a &struct int3472_discrete_device
192 *
193 * This function handles GPIO resources that are against an INT3472
194 * ACPI device, by checking the value of the corresponding _DSM entry.
195 * This will return a 32bit int, where the lowest byte represents the
196 * function of the GPIO pin:
197 *
198 * 0x00 Reset
199 * 0x01 Power down
200 * 0x0b Power enable
201 * 0x0c Clock enable
202 * 0x0d Privacy LED
203 *
204 * There are some known platform specific quirks where that does not quite
205 * hold up; for example where a pin with type 0x01 (Power down) is mapped to
206 * a sensor pin that performs a reset function or entries in _CRS and _DSM that
207 * do not actually correspond to a physical connection. These will be handled
208 * by the mapping sub-functions.
209 *
210 * GPIOs will either be mapped directly to the sensor device or else used
211 * to create clocks and regulators via the usual frameworks.
212 *
213 * Return:
214 * * 1		- To continue the loop
215 * * 0		- When all resources found are handled properly.
216 * * -EINVAL	- If the resource is not a GPIO IO resource
217 * * -ENODEV	- If the resource has no corresponding _DSM entry
218 * * -Other	- Errors propagated from one of the sub-functions.
219 */
220static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares,
221					     void *data)
222{
223	struct int3472_discrete_device *int3472 = data;
224	struct acpi_resource_gpio *agpio;
225	union acpi_object *obj;
226	const char *err_msg;
227	int ret;
228	u8 type;
229
230	if (!acpi_gpio_get_io_resource(ares, &agpio))
231		return 1;
232
233	/*
234	 * ngpios + 2 because the index of this _DSM function is 1-based and
235	 * the first function is just a count.
236	 */
237	obj = acpi_evaluate_dsm_typed(int3472->adev->handle,
238				      &int3472_gpio_guid, 0x00,
239				      int3472->ngpios + 2,
240				      NULL, ACPI_TYPE_INTEGER);
241
242	if (!obj) {
243		dev_warn(int3472->dev, "No _DSM entry for GPIO pin %u\n",
244			 agpio->pin_table[0]);
245		return 1;
246	}
247
248	type = obj->integer.value & 0xff;
249
250	switch (type) {
251	case INT3472_GPIO_TYPE_RESET:
252		ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, "reset",
253						     GPIO_ACTIVE_LOW);
254		if (ret)
255			err_msg = "Failed to map reset pin to sensor\n";
256
257		break;
258	case INT3472_GPIO_TYPE_POWERDOWN:
259		ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, "powerdown",
260						     GPIO_ACTIVE_LOW);
261		if (ret)
262			err_msg = "Failed to map powerdown pin to sensor\n";
263
264		break;
265	case INT3472_GPIO_TYPE_CLK_ENABLE:
266	case INT3472_GPIO_TYPE_PRIVACY_LED:
267		ret = skl_int3472_map_gpio_to_clk(int3472, agpio, type);
268		if (ret)
269			err_msg = "Failed to map GPIO to clock\n";
270
271		break;
272	case INT3472_GPIO_TYPE_POWER_ENABLE:
273		ret = skl_int3472_register_regulator(int3472, agpio);
274		if (ret)
275			err_msg = "Failed to map regulator to sensor\n";
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
295static int skl_int3472_parse_crs(struct int3472_discrete_device *int3472)
296{
297	LIST_HEAD(resource_list);
298	int ret;
299
300	/*
301	 * No error check, because not having a sensor config is not necessarily
302	 * a failure mode.
303	 */
304	int3472->sensor_config = skl_int3472_get_sensor_module_config(int3472);
305
306	ret = acpi_dev_get_resources(int3472->adev, &resource_list,
307				     skl_int3472_handle_gpio_resources,
308				     int3472);
309	if (ret < 0)
310		return ret;
311
312	acpi_dev_free_resource_list(&resource_list);
313
314	/*
315	 * If we find no clock enable GPIO pin then the privacy LED won't work.
316	 * We've never seen that situation, but it's possible. Warn the user so
317	 * it's clear what's happened.
318	 */
319	if (int3472->clock.ena_gpio) {
320		ret = skl_int3472_register_clock(int3472);
321		if (ret)
322			return ret;
323	} else {
324		if (int3472->clock.led_gpio)
325			dev_warn(int3472->dev,
326				 "No clk GPIO. The privacy LED won't work\n");
327	}
328
329	int3472->gpios.dev_id = int3472->sensor_name;
330	gpiod_add_lookup_table(&int3472->gpios);
331
332	return 0;
333}
334
335int 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
364	int3472->sensor = acpi_dev_get_first_consumer_dev(adev);
365	if (!int3472->sensor) {
366		dev_err(&pdev->dev, "INT3472 seems to have no dependents.\n");
367		return -ENODEV;
368	}
369
370	int3472->sensor_name = devm_kasprintf(int3472->dev, GFP_KERNEL,
371					      I2C_DEV_NAME_FORMAT,
372					      acpi_dev_name(int3472->sensor));
373	if (!int3472->sensor_name) {
374		ret = -ENOMEM;
375		goto err_put_sensor;
376	}
377
378	/*
379	 * Initialising this list means we can call gpiod_remove_lookup_table()
380	 * in failure paths without issue.
381	 */
382	INIT_LIST_HEAD(&int3472->gpios.list);
383
384	ret = skl_int3472_parse_crs(int3472);
385	if (ret) {
386		skl_int3472_discrete_remove(pdev);
387		return ret;
388	}
389
390	return 0;
391
392err_put_sensor:
393	acpi_dev_put(int3472->sensor);
394
395	return ret;
396}
397
398int skl_int3472_discrete_remove(struct platform_device *pdev)
399{
400	struct int3472_discrete_device *int3472 = platform_get_drvdata(pdev);
401
402	gpiod_remove_lookup_table(&int3472->gpios);
403
404	if (int3472->clock.ena_gpio)
405		skl_int3472_unregister_clock(int3472);
406
407	gpiod_put(int3472->clock.ena_gpio);
408	gpiod_put(int3472->clock.led_gpio);
409
410	skl_int3472_unregister_regulator(int3472);
411
412	return 0;
413}