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 */
25static 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 */
38static const guid_t cio2_sensor_module_guid =
39	GUID_INIT(0x822ace8f, 0x2814, 0x4174,
40		  0xa5, 0x6b, 0x5f, 0x02, 0x9f, 0xe0, 0x79, 0xee);
41
42static 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
55static 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
90static 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 */
152static 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
243static 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
269static 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
280static 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
331static const struct acpi_device_id int3472_device_id[] = {
332	{ "INT3472", 0 },
333	{ }
334};
335MODULE_DEVICE_TABLE(acpi, int3472_device_id);
336
337static 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};
345module_platform_driver(int3472_discrete);
346
347MODULE_DESCRIPTION("Intel SkyLake INT3472 ACPI Discrete Device Driver");
348MODULE_AUTHOR("Daniel Scally <djrscally@gmail.com>");
349MODULE_LICENSE("GPL v2");
350