drivers/pinctrl/qcom/pinctrl-qdf2xxx.c

Source file repositories/reference/linux-study-clean/drivers/pinctrl/qcom/pinctrl-qdf2xxx.c

File Facts

System
Linux kernel
Corpus path
drivers/pinctrl/qcom/pinctrl-qdf2xxx.c
Extension
.c
Size
4823 bytes
Lines
163
Domain
Driver Families
Bucket
drivers/pinctrl
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2015, The Linux Foundation. All rights reserved.
 *
 * GPIO and pin control functions on this SOC are handled by the "TLMM"
 * device.  The driver which controls this device is pinctrl-msm.c.  Each
 * SOC with a TLMM is expected to create a client driver that registers
 * with pinctrl-msm.c.  This means that all TLMM drivers are pin control
 * drivers.
 *
 * This pin control driver is intended to be used only an ACPI-enabled
 * system.  As such, UEFI will handle all pin control configuration, so
 * this driver does not provide pin control functions.  It is effectively
 * a GPIO-only driver.  The alternative is to duplicate the GPIO code of
 * pinctrl-msm.c into another driver.
 */

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/acpi.h>

#include "pinctrl-msm.h"

/* A maximum of 256 allows us to use a u8 array to hold the GPIO numbers */
#define MAX_GPIOS	256

/* maximum size of each gpio name (enough room for "gpioXXX" + null) */
#define NAME_SIZE	8

static int qdf2xxx_pinctrl_probe(struct platform_device *pdev)
{
	struct msm_pinctrl_soc_data *pinctrl;
	struct pinctrl_pin_desc *pins;
	struct msm_pingroup *groups;
	char (*names)[NAME_SIZE];
	unsigned int i;
	u32 num_gpios;
	unsigned int avail_gpios; /* The number of GPIOs we support */
	u8 gpios[MAX_GPIOS];      /* An array of supported GPIOs */
	int ret;

	/* Query the number of GPIOs from ACPI */
	ret = device_property_read_u32(&pdev->dev, "num-gpios", &num_gpios);
	if (ret < 0) {
		dev_err(&pdev->dev, "missing 'num-gpios' property\n");
		return ret;
	}
	if (!num_gpios || num_gpios > MAX_GPIOS) {
		dev_err(&pdev->dev, "invalid 'num-gpios' property\n");
		return -ENODEV;
	}

	/* The number of GPIOs in the approved list */
	ret = device_property_count_u8(&pdev->dev, "gpios");
	if (ret < 0) {
		dev_err(&pdev->dev, "missing 'gpios' property\n");
		return ret;
	}
	/*
	 * The number of available GPIOs should be non-zero, and no
	 * more than the total number of GPIOS.
	 */
	if (!ret || ret > num_gpios) {
		dev_err(&pdev->dev, "invalid 'gpios' property\n");
		return -ENODEV;
	}
	avail_gpios = ret;

	ret = device_property_read_u8_array(&pdev->dev, "gpios", gpios,
					    avail_gpios);
	if (ret < 0) {
		dev_err(&pdev->dev, "could not read list of GPIOs\n");
		return ret;
	}

	pinctrl = devm_kzalloc(&pdev->dev, sizeof(*pinctrl), GFP_KERNEL);
	pins = devm_kcalloc(&pdev->dev, num_gpios,
		sizeof(struct pinctrl_pin_desc), GFP_KERNEL);
	groups = devm_kcalloc(&pdev->dev, num_gpios,
		sizeof(struct msm_pingroup), GFP_KERNEL);
	names = devm_kcalloc(&pdev->dev, avail_gpios, NAME_SIZE, GFP_KERNEL);

	if (!pinctrl || !pins || !groups || !names)
		return -ENOMEM;

	/*
	 * Initialize the array.  GPIOs not listed in the 'gpios' array
	 * still need a number, but nothing else.
	 */

Annotation

Implementation Notes