u-boot/drivers/i2c/muxes/pca954x.c
Marek Behún 8e6eda7cda drivers/i2c/muxes/pca954x: Add pca9547 I2C mux support
This I2C mux is found, for example, on the Turris Omnia board.

Signed-off-by: Marek Behun <marek.behun@nic.cz>
Reviewed-by: Heiko Schocher <hs@denx.de>
Signed-off-by: Stefan Roese <sr@denx.de>
2017-07-12 06:56:48 +02:00

115 lines
2.3 KiB
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;
enum pca_type {
PCA9544,
PCA9547,
PCA9548
};
struct chip_desc {
u8 enable;
enum muxtype {
pca954x_ismux = 0,
pca954x_isswi,
} muxtype;
};
struct pca954x_priv {
u32 addr; /* I2C mux address */
u32 width; /* I2C mux width - number of busses */
};
static const struct chip_desc chips[] = {
[PCA9544] = {
.enable = 0x4,
.muxtype = pca954x_ismux,
},
[PCA9547] = {
.enable = 0x8,
.muxtype = pca954x_ismux,
},
[PCA9548] = {
.enable = 0x8,
.muxtype = pca954x_isswi,
},
};
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);
const struct chip_desc *chip = &chips[dev_get_driver_data(mux)];
uchar byte;
if (chip->muxtype == pca954x_ismux)
byte = channel | chip->enable;
else
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,pca9544", .data = PCA9544 },
{ .compatible = "nxp,pca9547", .data = PCA9547 },
{ .compatible = "nxp,pca9548", .data = PCA9548 },
{ }
};
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),
};