drivers/gpio/gpio-cros-ec.c

Source file repositories/reference/linux-study-clean/drivers/gpio/gpio-cros-ec.c

File Facts

System
Linux kernel
Corpus path
drivers/gpio/gpio-cros-ec.c
Extension
.c
Size
5750 bytes
Lines
215
Domain
Driver Families
Bucket
drivers/gpio
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

if (ret < 0) {
			dev_err_probe(gc->parent, ret, "error getting gpio%d info\n", i);
			return ret;
		}

		names[i] = str;
		copied = scnprintf(str, name_len, "%s%s", cros_ec_gpio_prefix,
				   response.get_info.name);
		if (copied < 0)
			return copied;

		str += copied + 1;
	}

	return 0;
}

/* Query EC for number of gpios */
static int cros_ec_gpio_ngpios(struct cros_ec_device *cros_ec)
{
	struct ec_params_gpio_get_v1 params = {
		.subcmd = EC_GPIO_GET_COUNT,
	};
	struct ec_response_gpio_get_v1 response;
	int ret;

	ret = cros_ec_cmd(cros_ec, 1, EC_CMD_GPIO_GET, &params,
			  sizeof(params), &response, sizeof(response));
	if (ret < 0)
		return ret;

	return response.get_count.val;
}

static int cros_ec_gpio_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct device *parent = dev->parent;
	struct cros_ec_dev *ec_dev = dev_get_drvdata(parent);
	struct cros_ec_device *cros_ec = ec_dev->ec_dev;
	struct gpio_chip *gc;
	int ngpios;
	int ret;

	/* Use the fwnode from the protocol device, e.g. cros-ec-spi */
	device_set_node(dev, dev_fwnode(cros_ec->dev));

	ngpios = cros_ec_gpio_ngpios(cros_ec);
	if (ngpios < 0) {
		dev_err_probe(dev, ngpios, "error getting gpio count\n");
		return ngpios;
	}

	gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL);
	if (!gc)
		return -ENOMEM;

	gc->ngpio = ngpios;
	gc->parent = dev;
	ret = cros_ec_gpio_init_names(cros_ec, gc);
	if (ret)
		return ret;

	gc->can_sleep = true;
	gc->label = dev_name(dev);
	gc->base = -1;
	gc->set = cros_ec_gpio_set;
	gc->get = cros_ec_gpio_get;
	gc->get_direction = cros_ec_gpio_get_direction;

	return devm_gpiochip_add_data(dev, gc, cros_ec);
}

static const struct platform_device_id cros_ec_gpio_id[] = {
	{ .name = "cros-ec-gpio" },
	{ }
};
MODULE_DEVICE_TABLE(platform, cros_ec_gpio_id);

static struct platform_driver cros_ec_gpio_driver = {
	.probe = cros_ec_gpio_probe,
	.driver = {
		.name = "cros-ec-gpio",
	},
	.id_table = cros_ec_gpio_id,
};
module_platform_driver(cros_ec_gpio_driver);

MODULE_DESCRIPTION("ChromeOS EC GPIO Driver");
MODULE_LICENSE("GPL");

Annotation

Implementation Notes