u-boot/drivers/i2c/muxes/pca954x.c

/*
 * Copyright (C) 2015 - 2016 Xilinx, Inc.
 * Written by Michal Simek
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <common.h>
#include <dm.h>
#include <errno.h>
#include <i2c.h>
#include <asm/gpio.h>

DECLARE_GLOBAL_DATA_PTR;

struct pca954x_priv {
	u32 addr; /* I2C mux address */
	u32 width; /* I2C mux width - number of busses */
};

static int pca954x_deselect(struct udevice *mux, struct udevice *bus,
			    uint channel)
{
	struct pca954x_priv *priv = dev_get_priv(mux);
	uchar byte = 0;

	return dm_i2c_write(mux, priv->addr, &byte, 1);
}

static int pca954x_select(struct udevice *mux, struct udevice *bus,
			  uint channel)
{
	struct pca954x_priv *priv = dev_get_priv(mux);
	uchar byte = 1 << channel;

	return dm_i2c_write(mux, priv->addr, &byte, 1);
}

static const struct i2c_mux_ops pca954x_ops = {
	.select = pca954x_select,
	.deselect = pca954x_deselect,
};

static const struct udevice_id pca954x_ids[] = {
	{ .compatible = "nxp,pca9548", .data = (ulong)8 },
	{ .compatible = "nxp,pca9544", .data = (ulong)4 },
	{ }
};

static int pca954x_ofdata_to_platdata(struct udevice *dev)
{
	struct pca954x_priv *priv = dev_get_priv(dev);

	priv->addr = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev), "reg", 0);
	if (!priv->addr) {
		debug("MUX not found\n");
		return -ENODEV;
	}
	priv->width = dev_get_driver_data(dev);

	if (!priv->width) {
		debug("No I2C MUX width specified\n");
		return -EINVAL;
	}

	debug("Device %s at 0x%x with width %d\n",
	      dev->name, priv->addr, priv->width);

	return 0;
}

U_BOOT_DRIVER(pca954x) = {
	.name = "pca954x",
	.id = UCLASS_I2C_MUX,
	.of_match = pca954x_ids,
	.ops = &pca954x_ops,
	.ofdata_to_platdata = pca954x_ofdata_to_platdata,
	.priv_auto_alloc_size = sizeof(struct pca954x_priv),
};