sandbox.c
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/*
* Copyright (c) 2011 The Chromium OS Authors.
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <fdtdec.h>
#include <malloc.h>
#include <asm/gpio.h>
#include <dt-bindings/gpio/gpio.h>
DECLARE_GLOBAL_DATA_PTR;
/* Flags for each GPIO */
#define GPIOF_OUTPUT (1 << 0) /* Currently set as an output */
#define GPIOF_HIGH (1 << 1) /* Currently set high */
struct gpio_state {
const char *label; /* label given by requester */
u8 flags; /* flags (GPIOF_...) */
};
/* Access routines for GPIO state */
static u8 *get_gpio_flags(struct udevice *dev, unsigned offset)
{
struct gpio_dev_priv *uc_priv = dev->uclass_priv;
struct gpio_state *state = dev_get_priv(dev);
if (offset >= uc_priv->gpio_count) {
static u8 invalid_flags;
printf("sandbox_gpio: error: invalid gpio %u\n", offset);
return &invalid_flags;
}
return &state[offset].flags;
}
static int get_gpio_flag(struct udevice *dev, unsigned offset, int flag)
{
return (*get_gpio_flags(dev, offset) & flag) != 0;
}
static int set_gpio_flag(struct udevice *dev, unsigned offset, int flag,
int value)
{
u8 *gpio = get_gpio_flags(dev, offset);
if (value)
*gpio |= flag;
else
*gpio &= ~flag;
return 0;
}
/*
* Back-channel sandbox-internal-only access to GPIO state
*/
int sandbox_gpio_get_value(struct udevice *dev, unsigned offset)
{
if (get_gpio_flag(dev, offset, GPIOF_OUTPUT))
debug("sandbox_gpio: get_value on output gpio %u\n", offset);
return get_gpio_flag(dev, offset, GPIOF_HIGH);
}
int sandbox_gpio_set_value(struct udevice *dev, unsigned offset, int value)
{
return set_gpio_flag(dev, offset, GPIOF_HIGH, value);
}
int sandbox_gpio_get_direction(struct udevice *dev, unsigned offset)
{
return get_gpio_flag(dev, offset, GPIOF_OUTPUT);
}
int sandbox_gpio_set_direction(struct udevice *dev, unsigned offset, int output)
{
return set_gpio_flag(dev, offset, GPIOF_OUTPUT, output);
}
/*
* These functions implement the public interface within U-Boot
*/
/* set GPIO port 'offset' as an input */
static int sb_gpio_direction_input(struct udevice *dev, unsigned offset)
{
debug("%s: offset:%u\n", __func__, offset);
return sandbox_gpio_set_direction(dev, offset, 0);
}
/* set GPIO port 'offset' as an output, with polarity 'value' */
static int sb_gpio_direction_output(struct udevice *dev, unsigned offset,
int value)
{
debug("%s: offset:%u, value = %d\n", __func__, offset, value);
return sandbox_gpio_set_direction(dev, offset, 1) |
sandbox_gpio_set_value(dev, offset, value);
}
/* read GPIO IN value of port 'offset' */
static int sb_gpio_get_value(struct udevice *dev, unsigned offset)
{
debug("%s: offset:%u\n", __func__, offset);
return sandbox_gpio_get_value(dev, offset);
}
/* write GPIO OUT value to port 'offset' */
static int sb_gpio_set_value(struct udevice *dev, unsigned offset, int value)
{
debug("%s: offset:%u, value = %d\n", __func__, offset, value);
if (!sandbox_gpio_get_direction(dev, offset)) {
printf("sandbox_gpio: error: set_value on input gpio %u\n",
offset);
return -1;
}
return sandbox_gpio_set_value(dev, offset, value);
}
static int sb_gpio_get_function(struct udevice *dev, unsigned offset)
{
if (get_gpio_flag(dev, offset, GPIOF_OUTPUT))
return GPIOF_OUTPUT;
return GPIOF_INPUT;
}
static int sb_gpio_xlate(struct udevice *dev, struct gpio_desc *desc,
struct fdtdec_phandle_args *args)
{
desc->offset = args->args[0];
if (args->args_count < 2)
return 0;
if (args->args[1] & GPIO_ACTIVE_LOW)
desc->flags |= GPIOD_ACTIVE_LOW;
if (args->args[1] & 2)
desc->flags |= GPIOD_IS_IN;
if (args->args[1] & 4)
desc->flags |= GPIOD_IS_OUT;
if (args->args[1] & 8)
desc->flags |= GPIOD_IS_OUT_ACTIVE;
return 0;
}
static const struct dm_gpio_ops gpio_sandbox_ops = {
.direction_input = sb_gpio_direction_input,
.direction_output = sb_gpio_direction_output,
.get_value = sb_gpio_get_value,
.set_value = sb_gpio_set_value,
.get_function = sb_gpio_get_function,
.xlate = sb_gpio_xlate,
};
static int sandbox_gpio_ofdata_to_platdata(struct udevice *dev)
{
struct gpio_dev_priv *uc_priv = dev->uclass_priv;
uc_priv->gpio_count = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
"num-gpios", 0);
uc_priv->bank_name = fdt_getprop(gd->fdt_blob, dev->of_offset,
"gpio-bank-name", NULL);
return 0;
}
static int gpio_sandbox_probe(struct udevice *dev)
{
struct gpio_dev_priv *uc_priv = dev->uclass_priv;
if (dev->of_offset == -1) {
/* Tell the uclass how many GPIOs we have */
uc_priv->gpio_count = CONFIG_SANDBOX_GPIO_COUNT;
}
dev->priv = calloc(sizeof(struct gpio_state), uc_priv->gpio_count);
return 0;
}
static int gpio_sandbox_remove(struct udevice *dev)
{
free(dev->priv);
return 0;
}
static const struct udevice_id sandbox_gpio_ids[] = {
{ .compatible = "sandbox,gpio" },
{ }
};
U_BOOT_DRIVER(gpio_sandbox) = {
.name = "gpio_sandbox",
.id = UCLASS_GPIO,
.of_match = sandbox_gpio_ids,
.ofdata_to_platdata = sandbox_gpio_ofdata_to_platdata,
.probe = gpio_sandbox_probe,
.remove = gpio_sandbox_remove,
.ops = &gpio_sandbox_ops,
};