u-boot/drivers/i2c/muxes/i2c-mux-gpio.c
Tom Rini 83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00

137 lines
2.9 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* I2C multiplexer using GPIO API
*
* Copyright 2017 NXP
*
* Peng Fan <peng.fan@nxp.com>
*/
#include <asm/io.h>
#include <asm-generic/gpio.h>
#include <common.h>
#include <dm.h>
#include <dm/pinctrl.h>
#include <fdtdec.h>
#include <i2c.h>
#include <linux/errno.h>
DECLARE_GLOBAL_DATA_PTR;
/**
* struct i2c_mux_gpio_priv - private data for i2c mux gpio
*
* @values: the reg value of each child node
* @n_values: num of regs
* @gpios: the mux-gpios array
* @n_gpios: num of gpios in mux-gpios
* @idle: the value of idle-state
*/
struct i2c_mux_gpio_priv {
u32 *values;
int n_values;
struct gpio_desc *gpios;
int n_gpios;
u32 idle;
};
static int i2c_mux_gpio_select(struct udevice *dev, struct udevice *bus,
uint channel)
{
struct i2c_mux_gpio_priv *priv = dev_get_priv(dev);
int i, ret;
for (i = 0; i < priv->n_gpios; i++) {
ret = dm_gpio_set_value(&priv->gpios[i], (channel >> i) & 1);
if (ret)
return ret;
}
return 0;
}
static int i2c_mux_gpio_deselect(struct udevice *dev, struct udevice *bus,
uint channel)
{
struct i2c_mux_gpio_priv *priv = dev_get_priv(dev);
int i, ret;
for (i = 0; i < priv->n_gpios; i++) {
ret = dm_gpio_set_value(&priv->gpios[i], (priv->idle >> i) & 1);
if (ret)
return ret;
}
return 0;
}
static int i2c_mux_gpio_probe(struct udevice *dev)
{
const void *fdt = gd->fdt_blob;
int node = dev_of_offset(dev);
struct i2c_mux_gpio_priv *mux = dev_get_priv(dev);
struct gpio_desc *gpios;
u32 *values;
int i = 0, subnode, ret;
mux->n_values = fdtdec_get_child_count(fdt, node);
values = devm_kzalloc(dev, sizeof(*mux->values) * mux->n_values,
GFP_KERNEL);
if (!values) {
dev_err(dev, "Cannot alloc values array");
return -ENOMEM;
}
fdt_for_each_subnode(subnode, fdt, node) {
*(values + i) = fdtdec_get_uint(fdt, subnode, "reg", -1);
i++;
}
mux->values = values;
mux->idle = fdtdec_get_uint(fdt, node, "idle-state", -1);
mux->n_gpios = gpio_get_list_count(dev, "mux-gpios");
if (mux->n_gpios < 0) {
dev_err(dev, "Missing mux-gpios property\n");
return -EINVAL;
}
gpios = devm_kzalloc(dev, sizeof(struct gpio_desc) * mux->n_gpios,
GFP_KERNEL);
if (!gpios) {
dev_err(dev, "Cannot allocate gpios array\n");
return -ENOMEM;
}
ret = gpio_request_list_by_name(dev, "mux-gpios", gpios, mux->n_gpios,
GPIOD_IS_OUT_ACTIVE);
if (ret <= 0) {
dev_err(dev, "Failed to request mux-gpios\n");
return ret;
}
mux->gpios = gpios;
return 0;
}
static const struct i2c_mux_ops i2c_mux_gpio_ops = {
.select = i2c_mux_gpio_select,
.deselect = i2c_mux_gpio_deselect,
};
static const struct udevice_id i2c_mux_gpio_ids[] = {
{ .compatible = "i2c-mux-gpio", },
{}
};
U_BOOT_DRIVER(i2c_mux_gpio) = {
.name = "i2c_mux_gpio",
.id = UCLASS_I2C_MUX,
.of_match = i2c_mux_gpio_ids,
.ops = &i2c_mux_gpio_ops,
.probe = i2c_mux_gpio_probe,
.priv_auto_alloc_size = sizeof(struct i2c_mux_gpio_priv),
};