u-boot/drivers/reboot-mode/reboot-mode-rtc.c
Nandor Han c74675bd90 reboot-mode: read the boot mode from RTC memory
RTC devices could provide battery-backed memory that can be used for
storing the reboot mode magic value.

Add a new reboot-mode back-end that uses RTC to store the reboot-mode
magic value. The driver also supports both endianness modes.

Signed-off-by: Nandor Han <nandor.han@vaisala.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2021-07-23 10:16:39 -04:00

127 lines
2.6 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c), Vaisala Oyj
*/
#include <common.h>
#include <dm.h>
#include <dm/device_compat.h>
#include <reboot-mode/reboot-mode-rtc.h>
#include <reboot-mode/reboot-mode.h>
#include <rtc.h>
DECLARE_GLOBAL_DATA_PTR;
static int reboot_mode_get(struct udevice *dev, u32 *buf)
{
if (!buf)
return -EINVAL;
int ret;
u8 *val = (u8 *)buf;
struct reboot_mode_rtc_platdata *plat_data;
plat_data = dev_get_plat(dev);
if (!plat_data)
return -EINVAL;
for (int i = 0; i < plat_data->size; i++) {
ret = rtc_read8(plat_data->rtc, plat_data->addr + i);
if (ret < 0)
return ret;
val[i] = ret;
}
if (plat_data->is_big_endian)
*buf = __be32_to_cpu(*buf);
else
*buf = __le32_to_cpu(*buf);
return 0;
}
static int reboot_mode_set(struct udevice *dev, u32 buf)
{
int ret;
u8 *val;
struct reboot_mode_rtc_platdata *plat_data;
plat_data = dev_get_plat(dev);
if (!plat_data)
return -EINVAL;
if (plat_data->is_big_endian)
buf = __cpu_to_be32(buf);
else
buf = __cpu_to_le32(buf);
val = (u8 *)&buf;
for (int i = 0; i < plat_data->size; i++) {
ret = rtc_write8(plat_data->rtc, (plat_data->addr + i), val[i]);
if (ret < 0)
return ret;
}
return 0;
}
#if CONFIG_IS_ENABLED(OF_CONTROL)
static int reboot_mode_ofdata_to_platdata(struct udevice *dev)
{
struct ofnode_phandle_args phandle_args;
struct reboot_mode_rtc_platdata *plat_data;
plat_data = dev_get_plat(dev);
if (!plat_data)
return -EINVAL;
if (dev_read_phandle_with_args(dev, "rtc", NULL, 0, 0, &phandle_args)) {
dev_err(dev, "RTC device not specified\n");
return -ENOENT;
}
if (uclass_get_device_by_ofnode(UCLASS_RTC, phandle_args.node,
&plat_data->rtc)) {
dev_err(dev, "could not get the RTC device\n");
return -ENODEV;
}
plat_data->addr =
dev_read_addr_size_index(dev, 0, (fdt_size_t *)&plat_data->size);
if (plat_data->addr == FDT_ADDR_T_NONE) {
dev_err(dev, "Invalid RTC address\n");
return -EINVAL;
}
if (plat_data->size > sizeof(u32)) {
dev_err(dev, "Invalid reg size\n");
return -EINVAL;
}
plat_data->is_big_endian = ofnode_read_bool(dev_ofnode(dev), "big-endian");
return 0;
}
static const struct udevice_id reboot_mode_ids[] = {
{ .compatible = "reboot-mode-rtc", 0 },
{}
};
#endif
static const struct reboot_mode_ops reboot_mode_rtc_ops = {
.get = reboot_mode_get,
.set = reboot_mode_set,
};
U_BOOT_DRIVER(reboot_mode_rtc) = {
.name = "reboot-mode-rtc",
.id = UCLASS_REBOOT_MODE,
#if CONFIG_IS_ENABLED(OF_CONTROL)
.of_match = reboot_mode_ids,
.of_to_plat = reboot_mode_ofdata_to_platdata,
#endif
.plat_auto = sizeof(struct reboot_mode_rtc_platdata),
.ops = &reboot_mode_rtc_ops,
};