u-boot/drivers/sysinfo/gpio.c
Sean Anderson 54aa07fdfc sysinfo: Add gpio-sysinfo driver
This uses the newly-added dm_gpio_get_values_as_int_base3 function to
implement a sysinfo device. The revision map is stored in the device tree.

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2021-05-04 07:57:18 -04:00

142 lines
3.1 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2021 Sean Anderson <sean.anderson@seco.com>
*/
#include <common.h>
#include <dm.h>
#include <log.h>
#include <sysinfo.h>
#include <asm/gpio.h>
#include <dm/device_compat.h>
/**
* struct sysinfo_gpio_priv - GPIO sysinfo private data
* @gpios: List of GPIOs used to detect the revision
* @gpio_num: The number of GPIOs in @gpios
* @revision: The revision as detected from the GPIOs.
*/
struct sysinfo_gpio_priv {
struct gpio_desc *gpios;
int gpio_num, revision;
};
static int sysinfo_gpio_detect(struct udevice *dev)
{
int ret;
struct sysinfo_gpio_priv *priv = dev_get_priv(dev);
ret = dm_gpio_get_values_as_int_base3(priv->gpios, priv->gpio_num);
if (ret < 0)
return ret;
priv->revision = ret;
return 0;
}
static int sysinfo_gpio_get_int(struct udevice *dev, int id, int *val)
{
struct sysinfo_gpio_priv *priv = dev_get_priv(dev);
switch (id) {
case SYSINFO_ID_BOARD_MODEL:
*val = priv->revision;
return 0;
default:
return -EINVAL;
};
}
static int sysinfo_gpio_get_str(struct udevice *dev, int id, size_t size, char *val)
{
struct sysinfo_gpio_priv *priv = dev_get_priv(dev);
switch (id) {
case SYSINFO_ID_BOARD_MODEL: {
const char *name = NULL;
int i, ret;
u32 revision;
for (i = 0; i < priv->gpio_num; i++) {
ret = dev_read_u32_index(dev, "revisions", i,
&revision);
if (ret) {
if (ret != -EOVERFLOW)
return ret;
break;
}
if (revision == priv->revision) {
ret = dev_read_string_index(dev, "names", i,
&name);
if (ret < 0)
return ret;
break;
}
}
if (!name)
name = "unknown";
strncpy(val, name, size);
val[size - 1] = '\0';
return 0;
} default:
return -EINVAL;
};
}
static const struct sysinfo_ops sysinfo_gpio_ops = {
.detect = sysinfo_gpio_detect,
.get_int = sysinfo_gpio_get_int,
.get_str = sysinfo_gpio_get_str,
};
static int sysinfo_gpio_probe(struct udevice *dev)
{
int ret;
struct sysinfo_gpio_priv *priv = dev_get_priv(dev);
priv->gpio_num = gpio_get_list_count(dev, "gpios");
if (priv->gpio_num < 0) {
dev_err(dev, "could not get gpios length (err = %d)\n",
priv->gpio_num);
return priv->gpio_num;
}
priv->gpios = calloc(priv->gpio_num, sizeof(*priv->gpios));
if (!priv->gpios) {
dev_err(dev, "could not allocate memory for %d gpios\n",
priv->gpio_num);
return -ENOMEM;
}
ret = gpio_request_list_by_name(dev, "gpios", priv->gpios,
priv->gpio_num, GPIOD_IS_IN);
if (ret != priv->gpio_num) {
dev_err(dev, "could not get gpios (err = %d)\n",
priv->gpio_num);
return ret;
}
if (!dev_read_bool(dev, "revisions") || !dev_read_bool(dev, "names")) {
dev_err(dev, "revisions or names properties missing\n");
return -ENOENT;
}
return 0;
}
static const struct udevice_id sysinfo_gpio_ids[] = {
{ .compatible = "gpio-sysinfo" },
{ /* sentinel */ }
};
U_BOOT_DRIVER(sysinfo_gpio) = {
.name = "sysinfo_gpio",
.id = UCLASS_SYSINFO,
.of_match = sysinfo_gpio_ids,
.ops = &sysinfo_gpio_ops,
.priv_auto = sizeof(struct sysinfo_gpio_priv),
.probe = sysinfo_gpio_probe,
};