Philipp Tomsich | 57be882 | 2018-11-27 23:00:19 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0+ |
| 2 | /* |
| 3 | * (C) Copyright 2018 Theobroma Systems Design und Consulting GmbH |
| 4 | */ |
| 5 | |
| 6 | #include <common.h> |
| 7 | #include <bootcount.h> |
| 8 | #include <dm.h> |
Simon Glass | 0f2af88 | 2020-05-10 11:40:05 -0600 | [diff] [blame] | 9 | #include <log.h> |
Philipp Tomsich | 57be882 | 2018-11-27 23:00:19 +0100 | [diff] [blame] | 10 | #include <rtc.h> |
| 11 | |
| 12 | static const u8 bootcount_magic = 0xbc; |
| 13 | |
| 14 | struct bootcount_rtc_priv { |
| 15 | struct udevice *rtc; |
| 16 | u32 offset; |
| 17 | }; |
| 18 | |
| 19 | static int bootcount_rtc_set(struct udevice *dev, const u32 a) |
| 20 | { |
| 21 | struct bootcount_rtc_priv *priv = dev_get_priv(dev); |
| 22 | const u16 val = bootcount_magic << 8 | (a & 0xff); |
| 23 | |
| 24 | if (rtc_write16(priv->rtc, priv->offset, val) < 0) { |
| 25 | debug("%s: rtc_write16 failed\n", __func__); |
| 26 | return -EIO; |
| 27 | } |
| 28 | |
| 29 | return 0; |
| 30 | } |
| 31 | |
| 32 | static int bootcount_rtc_get(struct udevice *dev, u32 *a) |
| 33 | { |
| 34 | struct bootcount_rtc_priv *priv = dev_get_priv(dev); |
| 35 | u16 val; |
| 36 | |
| 37 | if (rtc_read16(priv->rtc, priv->offset, &val) < 0) { |
| 38 | debug("%s: rtc_write16 failed\n", __func__); |
| 39 | return -EIO; |
| 40 | } |
| 41 | |
| 42 | if (val >> 8 == bootcount_magic) { |
| 43 | *a = val & 0xff; |
| 44 | return 0; |
| 45 | } |
| 46 | |
| 47 | debug("%s: bootcount magic does not match on %04x\n", __func__, val); |
| 48 | return -EIO; |
| 49 | } |
| 50 | |
| 51 | static int bootcount_rtc_probe(struct udevice *dev) |
| 52 | { |
| 53 | struct ofnode_phandle_args phandle_args; |
| 54 | struct bootcount_rtc_priv *priv = dev_get_priv(dev); |
| 55 | struct udevice *rtc; |
| 56 | |
| 57 | if (dev_read_phandle_with_args(dev, "rtc", NULL, 0, 0, &phandle_args)) { |
| 58 | debug("%s: rtc backing device not specified\n", dev->name); |
| 59 | return -ENOENT; |
| 60 | } |
| 61 | |
| 62 | if (uclass_get_device_by_ofnode(UCLASS_RTC, phandle_args.node, &rtc)) { |
| 63 | debug("%s: could not get backing device\n", dev->name); |
| 64 | return -ENODEV; |
| 65 | } |
| 66 | |
| 67 | priv->rtc = rtc; |
| 68 | priv->offset = dev_read_u32_default(dev, "offset", 0); |
| 69 | |
| 70 | return 0; |
| 71 | } |
| 72 | |
| 73 | static const struct bootcount_ops bootcount_rtc_ops = { |
| 74 | .get = bootcount_rtc_get, |
| 75 | .set = bootcount_rtc_set, |
| 76 | }; |
| 77 | |
| 78 | static const struct udevice_id bootcount_rtc_ids[] = { |
| 79 | { .compatible = "u-boot,bootcount-rtc" }, |
| 80 | { } |
| 81 | }; |
| 82 | |
| 83 | U_BOOT_DRIVER(bootcount_rtc) = { |
| 84 | .name = "bootcount-rtc", |
| 85 | .id = UCLASS_BOOTCOUNT, |
| 86 | .priv_auto_alloc_size = sizeof(struct bootcount_rtc_priv), |
| 87 | .probe = bootcount_rtc_probe, |
| 88 | .of_match = bootcount_rtc_ids, |
| 89 | .ops = &bootcount_rtc_ops, |
| 90 | }; |