91 lines
2.0 KiB
C
91 lines
2.0 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* (C) Copyright 2018 Theobroma Systems Design und Consulting GmbH
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*/
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#include <common.h>
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#include <bootcount.h>
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#include <dm.h>
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#include <log.h>
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#include <rtc.h>
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static const u8 bootcount_magic = 0xbc;
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struct bootcount_rtc_priv {
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struct udevice *rtc;
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u32 offset;
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};
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static int bootcount_rtc_set(struct udevice *dev, const u32 a)
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{
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struct bootcount_rtc_priv *priv = dev_get_priv(dev);
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const u16 val = bootcount_magic << 8 | (a & 0xff);
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if (rtc_write16(priv->rtc, priv->offset, val) < 0) {
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debug("%s: rtc_write16 failed\n", __func__);
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return -EIO;
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}
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return 0;
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}
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static int bootcount_rtc_get(struct udevice *dev, u32 *a)
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{
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struct bootcount_rtc_priv *priv = dev_get_priv(dev);
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u16 val;
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if (rtc_read16(priv->rtc, priv->offset, &val) < 0) {
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debug("%s: rtc_write16 failed\n", __func__);
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return -EIO;
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}
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if (val >> 8 == bootcount_magic) {
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*a = val & 0xff;
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return 0;
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}
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debug("%s: bootcount magic does not match on %04x\n", __func__, val);
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return -EIO;
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}
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static int bootcount_rtc_probe(struct udevice *dev)
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{
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struct ofnode_phandle_args phandle_args;
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struct bootcount_rtc_priv *priv = dev_get_priv(dev);
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struct udevice *rtc;
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if (dev_read_phandle_with_args(dev, "rtc", NULL, 0, 0, &phandle_args)) {
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debug("%s: rtc backing device not specified\n", dev->name);
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return -ENOENT;
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}
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if (uclass_get_device_by_ofnode(UCLASS_RTC, phandle_args.node, &rtc)) {
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debug("%s: could not get backing device\n", dev->name);
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return -ENODEV;
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}
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priv->rtc = rtc;
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priv->offset = dev_read_u32_default(dev, "offset", 0);
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return 0;
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}
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static const struct bootcount_ops bootcount_rtc_ops = {
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.get = bootcount_rtc_get,
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.set = bootcount_rtc_set,
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};
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static const struct udevice_id bootcount_rtc_ids[] = {
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{ .compatible = "u-boot,bootcount-rtc" },
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{ }
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};
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U_BOOT_DRIVER(bootcount_rtc) = {
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.name = "bootcount-rtc",
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.id = UCLASS_BOOTCOUNT,
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.priv_auto_alloc_size = sizeof(struct bootcount_rtc_priv),
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.probe = bootcount_rtc_probe,
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.of_match = bootcount_rtc_ids,
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.ops = &bootcount_rtc_ops,
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};
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