linux/drivers/platform/x86/intel/int3472/discrete.c

// SPDX-License-Identifier: GPL-2.0
/* Author: Dan Scally <[email protected]> */

#include <linux/acpi.h>
#include <linux/bitfield.h>
#include <linux/device.h>
#include <linux/gpio/consumer.h>
#include <linux/gpio/machine.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/overflow.h>
#include <linux/platform_device.h>
#include <linux/uuid.h>

#include "common.h"

/*
 * 79234640-9e10-4fea-a5c1-b5aa8b19756f
 * This _DSM GUID returns information about the GPIO lines mapped to a
 * discrete INT3472 device. Function number 1 returns a count of the GPIO
 * lines that are mapped. Subsequent functions return 32 bit ints encoding
 * information about the GPIO line, including its purpose.
 */
static const guid_t int3472_gpio_guid = …;

#define INT3472_GPIO_DSM_TYPE …
#define INT3472_GPIO_DSM_PIN …
#define INT3472_GPIO_DSM_SENSOR_ON_VAL …

/*
 * 822ace8f-2814-4174-a56b-5f029fe079ee
 * This _DSM GUID returns a string from the sensor device, which acts as a
 * module identifier.
 */
static const guid_t cio2_sensor_module_guid = …;

static void skl_int3472_log_sensor_module_name(struct int3472_discrete_device *int3472)
{ … }

static int skl_int3472_fill_gpiod_lookup(struct gpiod_lookup *table_entry,
					 struct acpi_resource_gpio *agpio,
					 const char *func, u32 polarity)
{ … }

static int skl_int3472_map_gpio_to_sensor(struct int3472_discrete_device *int3472,
					  struct acpi_resource_gpio *agpio,
					  const char *func, u32 polarity)
{ … }

/* This should *really* only be used when there's no other way... */
static struct gpio_desc *
skl_int3472_gpiod_get_from_temp_lookup(struct int3472_discrete_device *int3472,
				       struct acpi_resource_gpio *agpio,
				       const char *func, u32 polarity)
{ … }

static void int3472_get_func_and_polarity(u8 type, const char **func, u32 *polarity)
{ … }

/**
 * skl_int3472_handle_gpio_resources: Map PMIC resources to consuming sensor
 * @ares: A pointer to a &struct acpi_resource
 * @data: A pointer to a &struct int3472_discrete_device
 *
 * This function handles GPIO resources that are against an INT3472
 * ACPI device, by checking the value of the corresponding _DSM entry.
 * This will return a 32bit int, where the lowest byte represents the
 * function of the GPIO pin:
 *
 * 0x00 Reset
 * 0x01 Power down
 * 0x0b Power enable
 * 0x0c Clock enable
 * 0x0d Privacy LED
 *
 * There are some known platform specific quirks where that does not quite
 * hold up; for example where a pin with type 0x01 (Power down) is mapped to
 * a sensor pin that performs a reset function or entries in _CRS and _DSM that
 * do not actually correspond to a physical connection. These will be handled
 * by the mapping sub-functions.
 *
 * GPIOs will either be mapped directly to the sensor device or else used
 * to create clocks and regulators via the usual frameworks.
 *
 * Return:
 * * 1		- To continue the loop
 * * 0		- When all resources found are handled properly.
 * * -EINVAL	- If the resource is not a GPIO IO resource
 * * -ENODEV	- If the resource has no corresponding _DSM entry
 * * -Other	- Errors propagated from one of the sub-functions.
 */
static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares,
					     void *data)
{ … }

static int skl_int3472_parse_crs(struct int3472_discrete_device *int3472)
{ … }

static void skl_int3472_discrete_remove(struct platform_device *pdev)
{ … }

static int skl_int3472_discrete_probe(struct platform_device *pdev)
{ … }

static const struct acpi_device_id int3472_device_id[] = …;
MODULE_DEVICE_TABLE(acpi, int3472_device_id);

static struct platform_driver int3472_discrete = …;
module_platform_driver(…) …;

MODULE_DESCRIPTION(…) …;
MODULE_AUTHOR(…) …;
MODULE_LICENSE(…) …;