drivers/mfd/simple-mfd-i2c.c

Source file repositories/reference/linux-study-clean/drivers/mfd/simple-mfd-i2c.c

File Facts

System
Linux kernel
Corpus path
drivers/mfd/simple-mfd-i2c.c
Extension
.c
Size
4253 bytes
Lines
146
Domain
Driver Families
Bucket
drivers/mfd
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
/*
 * Simple MFD - I2C
 *
 * Author(s):
 * 	Michael Walle <michael@walle.cc>
 * 	Lee Jones <lee.jones@linaro.org>
 *
 * This driver creates a single register map with the intention for it to be
 * shared by all sub-devices.  Children can use their parent's device structure
 * (dev.parent) in order to reference it.
 *
 * Once the register map has been successfully initialised, any sub-devices
 * represented by child nodes in Device Tree or via the MFD cells in this file
 * will be subsequently registered.
 */

#include <linux/array_size.h>
#include <linux/dev_printk.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/mfd/core.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/stddef.h>

#include "simple-mfd-i2c.h"

static const struct regmap_config regmap_config_8r_8v = {
	.reg_bits = 8,
	.val_bits = 8,
};

static int simple_mfd_i2c_probe(struct i2c_client *i2c)
{
	const struct simple_mfd_data *simple_mfd_data;
	const struct regmap_config *regmap_config;
	struct regmap *regmap;
	int ret;

	simple_mfd_data = device_get_match_data(&i2c->dev);

	/* If no regmap_config is specified, use the default 8reg and 8val bits */
	if (!simple_mfd_data || !simple_mfd_data->regmap_config)
		regmap_config = &regmap_config_8r_8v;
	else
		regmap_config = simple_mfd_data->regmap_config;

	regmap = devm_regmap_init_i2c(i2c, regmap_config);
	if (IS_ERR(regmap))
		return PTR_ERR(regmap);

	/* If no MFD cells are specified, register using the DT child nodes instead */
	if (!simple_mfd_data || !simple_mfd_data->mfd_cell)
		return devm_of_platform_populate(&i2c->dev);

	ret = devm_mfd_add_devices(&i2c->dev, PLATFORM_DEVID_AUTO,
				   simple_mfd_data->mfd_cell,
				   simple_mfd_data->mfd_cell_size,
				   NULL, 0, NULL);
	if (ret)
		dev_err(&i2c->dev, "Failed to add child devices\n");

	return ret;
}

static const struct mfd_cell sy7636a_cells[] = {
	{ .name = "sy7636a-regulator", },
	{ .name = "sy7636a-temperature", },
};

static const struct simple_mfd_data silergy_sy7636a = {
	.mfd_cell = sy7636a_cells,
	.mfd_cell_size = ARRAY_SIZE(sy7636a_cells),
};

static const struct mfd_cell max5970_cells[] = {
	{ .name = "max5970-regulator", },
	{ .name = "max5970-iio", },
	{ .name = "max5970-led", },
};

static const struct simple_mfd_data maxim_max5970 = {
	.mfd_cell = max5970_cells,
	.mfd_cell_size = ARRAY_SIZE(max5970_cells),
};

Annotation

Implementation Notes