From patchwork Mon Jul 10 12:31:28 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alistair Francis X-Patchwork-Id: 13306880 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 28D39EB64D9 for ; Mon, 10 Jul 2023 12:34:01 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qIq4z-00021f-F0; Mon, 10 Jul 2023 08:33:25 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qIq4x-0001vn-28 for qemu-devel@nongnu.org; Mon, 10 Jul 2023 08:33:23 -0400 Received: from mail-oi1-x234.google.com ([2607:f8b0:4864:20::234]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1qIq4u-0004P7-Je for qemu-devel@nongnu.org; Mon, 10 Jul 2023 08:33:22 -0400 Received: by mail-oi1-x234.google.com with SMTP id 5614622812f47-3a40b756eb0so299737b6e.2 for ; Mon, 10 Jul 2023 05:33:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1688992399; x=1691584399; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=FWkbeZFrqlYJ3WztiBirpPmZASraWWKKzzEPMwH2zR8=; b=sGT01YW5nsWWcgcXD5pL996UE9bMQqeSrbwMrx/5IJF+uVc/D4P6y2vg7dyEd/CGbt T5dENv8oScLJcwHWtbNWoATWrCp6mcwuyJe8d0T57siVTQkjBtti5Jof/XieS112sbHV PWi33OVqAkPwEuGaGj5BzitfL/QNgULac7QtxqtXc8c/NY4NMEB3WGuQH08RJUP9A1c/ pIh7RRIqEp3O21HyUciOYEk8Uov8cfbsVMZwwPmtlwkIyMN/OVwxtEIaKoANXOaybIWT VAPtXLRZHGuDRSM1SZYciSulUa95BokbJCZdCY5N1n5iEEE+NDLbTTDxSsEKZh7qiPDR tQDg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1688992399; x=1691584399; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=FWkbeZFrqlYJ3WztiBirpPmZASraWWKKzzEPMwH2zR8=; b=PjPrlx1Uqus89Yzf4lzfbpetE2AhdXF1SwiEiR/qnf/l02Q92aQ4WQaT6o5s92Ukpz NWHssrhpk+Qw8bLsWSuiLzybNtbZk6QXLk44yda6hNmY/RaVn3exSEw7CKAQpCFZ4MYX zIUONPVsYryHbetvtWLiVu6e/J3OyO2KwSIGtYwzXetUSPSoaeD0JuiFdC9K5nUtL5sC +sPbSldJSmAIBBfRNfG4fFzJc5nFqg1htOtXvt7ksIQA13Z0IbA+XVG9mnEramwJQuhl QZ3VeVfgeTIixQli4FwY7YpjgycP1lJ/MTFwB5J5FwsV8+RpBVEpsSlb40w/8+13oJ1q ZU4w== X-Gm-Message-State: ABy/qLaV4YnOr6mPr2x6w1cPpuHGJrwnO6UMHeHvxY6sNiWHnr3s22JM VEHQORKL8nUjOUrxT2VbfhwjaYENdaC6lw== X-Google-Smtp-Source: APBJJlFbTwYoI7JgEaeM/5iHtFsBlANZZuvrU8pQe2OdjWjatpE/dIJavCPTW6WVdTs3MkU7kDYdJg== X-Received: by 2002:a05:6808:2905:b0:3a3:63b8:fdc7 with SMTP id ev5-20020a056808290500b003a363b8fdc7mr10629827oib.38.1688992399145; Mon, 10 Jul 2023 05:33:19 -0700 (PDT) Received: from toolbox.alistair23.me (2403-580b-97e8-0-321-6fb2-58f1-a1b1.ip6.aussiebb.net. [2403:580b:97e8:0:321:6fb2:58f1:a1b1]) by smtp.gmail.com with ESMTPSA id i126-20020a639d84000000b0055b44a901absm181559pgd.70.2023.07.10.05.33.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 10 Jul 2023 05:33:18 -0700 (PDT) From: Alistair Francis X-Google-Original-From: Alistair Francis To: qemu-devel@nongnu.org Cc: alistair23@gmail.com, Tommy Wu , Frank Chang , Alistair Francis Subject: [PULL 17/54] hw/misc: sifive_e_aon: Support the watchdog timer of HiFive 1 rev b. Date: Mon, 10 Jul 2023 22:31:28 +1000 Message-Id: <20230710123205.2441106-18-alistair.francis@wdc.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230710123205.2441106-1-alistair.francis@wdc.com> References: <20230710123205.2441106-1-alistair.francis@wdc.com> MIME-Version: 1.0 Received-SPF: pass client-ip=2607:f8b0:4864:20::234; envelope-from=alistair23@gmail.com; helo=mail-oi1-x234.google.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Tommy Wu The watchdog timer is in the always-on domain device of HiFive 1 rev b, so this patch added the AON device to the sifive_e machine. This patch only implemented the functionality of the watchdog timer. Signed-off-by: Tommy Wu Reviewed-by: Frank Chang Acked-by: Alistair Francis Message-Id: <20230627141216.3962299-2-tommy.wu@sifive.com> Signed-off-by: Alistair Francis --- include/hw/misc/sifive_e_aon.h | 60 +++++++ hw/misc/sifive_e_aon.c | 319 +++++++++++++++++++++++++++++++++ hw/misc/Kconfig | 3 + hw/misc/meson.build | 1 + 4 files changed, 383 insertions(+) create mode 100644 include/hw/misc/sifive_e_aon.h create mode 100644 hw/misc/sifive_e_aon.c diff --git a/include/hw/misc/sifive_e_aon.h b/include/hw/misc/sifive_e_aon.h new file mode 100644 index 0000000000..2ae1c4139c --- /dev/null +++ b/include/hw/misc/sifive_e_aon.h @@ -0,0 +1,60 @@ +/* + * SiFive HiFive1 AON (Always On Domain) interface. + * + * Copyright (c) 2022 SiFive, Inc. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2 or later, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see . + */ + +#ifndef HW_SIFIVE_AON_H +#define HW_SIFIVE_AON_H + +#include "hw/sysbus.h" +#include "qom/object.h" + +#define TYPE_SIFIVE_E_AON "riscv.sifive.e.aon" +OBJECT_DECLARE_SIMPLE_TYPE(SiFiveEAONState, SIFIVE_E_AON) + +#define SIFIVE_E_AON_WDOGKEY (0x51F15E) +#define SIFIVE_E_AON_WDOGFEED (0xD09F00D) +#define SIFIVE_E_LFCLK_DEFAULT_FREQ (32768) + +enum { + SIFIVE_E_AON_WDT = 0x0, + SIFIVE_E_AON_RTC = 0x40, + SIFIVE_E_AON_LFROSC = 0x70, + SIFIVE_E_AON_BACKUP = 0x80, + SIFIVE_E_AON_PMU = 0x100, + SIFIVE_E_AON_MAX = 0x150 +}; + +struct SiFiveEAONState { + /*< private >*/ + SysBusDevice parent_obj; + + /*< public >*/ + MemoryRegion mmio; + + /*< watchdog timer >*/ + QEMUTimer *wdog_timer; + qemu_irq wdog_irq; + uint64_t wdog_restart_time; + uint64_t wdogclk_freq; + + uint32_t wdogcfg; + uint16_t wdogcmp0; + uint32_t wdogcount; + uint8_t wdogunlock; +}; + +#endif diff --git a/hw/misc/sifive_e_aon.c b/hw/misc/sifive_e_aon.c new file mode 100644 index 0000000000..4656457d0b --- /dev/null +++ b/hw/misc/sifive_e_aon.c @@ -0,0 +1,319 @@ +/* + * SiFive HiFive1 AON (Always On Domain) for QEMU. + * + * Copyright (c) 2022 SiFive, Inc. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2 or later, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see . + */ + +#include "qemu/osdep.h" +#include "qemu/timer.h" +#include "qemu/log.h" +#include "hw/irq.h" +#include "hw/registerfields.h" +#include "hw/misc/sifive_e_aon.h" +#include "qapi/visitor.h" +#include "qapi/error.h" +#include "sysemu/watchdog.h" +#include "hw/qdev-properties.h" + +REG32(AON_WDT_WDOGCFG, 0x0) + FIELD(AON_WDT_WDOGCFG, SCALE, 0, 4) + FIELD(AON_WDT_WDOGCFG, RSVD0, 4, 4) + FIELD(AON_WDT_WDOGCFG, RSTEN, 8, 1) + FIELD(AON_WDT_WDOGCFG, ZEROCMP, 9, 1) + FIELD(AON_WDT_WDOGCFG, RSVD1, 10, 2) + FIELD(AON_WDT_WDOGCFG, EN_ALWAYS, 12, 1) + FIELD(AON_WDT_WDOGCFG, EN_CORE_AWAKE, 13, 1) + FIELD(AON_WDT_WDOGCFG, RSVD2, 14, 14) + FIELD(AON_WDT_WDOGCFG, IP0, 28, 1) + FIELD(AON_WDT_WDOGCFG, RSVD3, 29, 3) +REG32(AON_WDT_WDOGCOUNT, 0x8) + FIELD(AON_WDT_WDOGCOUNT, VALUE, 0, 31) +REG32(AON_WDT_WDOGS, 0x10) +REG32(AON_WDT_WDOGFEED, 0x18) +REG32(AON_WDT_WDOGKEY, 0x1c) +REG32(AON_WDT_WDOGCMP0, 0x20) + +static void sifive_e_aon_wdt_update_wdogcount(SiFiveEAONState *r) +{ + int64_t now; + if (FIELD_EX32(r->wdogcfg, AON_WDT_WDOGCFG, EN_ALWAYS) == 0 && + FIELD_EX32(r->wdogcfg, AON_WDT_WDOGCFG, EN_CORE_AWAKE) == 0) { + return; + } + + now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); + r->wdogcount += muldiv64(now - r->wdog_restart_time, + r->wdogclk_freq, NANOSECONDS_PER_SECOND); + + /* Clean the most significant bit. */ + r->wdogcount &= R_AON_WDT_WDOGCOUNT_VALUE_MASK; + r->wdog_restart_time = now; +} + +static void sifive_e_aon_wdt_update_state(SiFiveEAONState *r) +{ + uint16_t wdogs; + bool cmp_signal = false; + sifive_e_aon_wdt_update_wdogcount(r); + wdogs = (uint16_t)(r->wdogcount >> + FIELD_EX32(r->wdogcfg, AON_WDT_WDOGCFG, SCALE)); + + if (wdogs >= r->wdogcmp0) { + cmp_signal = true; + if (FIELD_EX32(r->wdogcfg, AON_WDT_WDOGCFG, ZEROCMP) == 1) { + r->wdogcount = 0; + wdogs = 0; + } + } + + if (cmp_signal) { + if (FIELD_EX32(r->wdogcfg, AON_WDT_WDOGCFG, RSTEN) == 1) { + watchdog_perform_action(); + } + r->wdogcfg = FIELD_DP32(r->wdogcfg, AON_WDT_WDOGCFG, IP0, 1); + } + + qemu_set_irq(r->wdog_irq, FIELD_EX32(r->wdogcfg, AON_WDT_WDOGCFG, IP0)); + + if (wdogs < r->wdogcmp0 && + (FIELD_EX32(r->wdogcfg, AON_WDT_WDOGCFG, EN_ALWAYS) == 1 || + FIELD_EX32(r->wdogcfg, AON_WDT_WDOGCFG, EN_CORE_AWAKE) == 1)) { + int64_t next = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); + next += muldiv64((r->wdogcmp0 - wdogs) << + FIELD_EX32(r->wdogcfg, AON_WDT_WDOGCFG, SCALE), + NANOSECONDS_PER_SECOND, r->wdogclk_freq); + timer_mod(r->wdog_timer, next); + } else { + timer_mod(r->wdog_timer, INT64_MAX); + } +} + +/* + * Callback used when the timer set using timer_mod expires. + */ +static void sifive_e_aon_wdt_expired_cb(void *opaque) +{ + SiFiveEAONState *r = SIFIVE_E_AON(opaque); + sifive_e_aon_wdt_update_state(r); +} + +static uint64_t +sifive_e_aon_wdt_read(void *opaque, hwaddr addr, unsigned int size) +{ + SiFiveEAONState *r = SIFIVE_E_AON(opaque); + + switch (addr) { + case A_AON_WDT_WDOGCFG: + return r->wdogcfg; + case A_AON_WDT_WDOGCOUNT: + sifive_e_aon_wdt_update_wdogcount(r); + return r->wdogcount; + case A_AON_WDT_WDOGS: + sifive_e_aon_wdt_update_wdogcount(r); + return r->wdogcount >> + FIELD_EX32(r->wdogcfg, + AON_WDT_WDOGCFG, + SCALE); + case A_AON_WDT_WDOGFEED: + return 0; + case A_AON_WDT_WDOGKEY: + return r->wdogunlock; + case A_AON_WDT_WDOGCMP0: + return r->wdogcmp0; + default: + qemu_log_mask(LOG_GUEST_ERROR, "%s: bad read: addr=0x%x\n", + __func__, (int)addr); + } + + return 0; +} + +static void +sifive_e_aon_wdt_write(void *opaque, hwaddr addr, + uint64_t val64, unsigned int size) +{ + SiFiveEAONState *r = SIFIVE_E_AON(opaque); + uint32_t value = val64; + + switch (addr) { + case A_AON_WDT_WDOGCFG: { + uint8_t new_en_always; + uint8_t new_en_core_awake; + uint8_t old_en_always; + uint8_t old_en_core_awake; + if (r->wdogunlock == 0) { + return; + } + + new_en_always = FIELD_EX32(value, AON_WDT_WDOGCFG, EN_ALWAYS); + new_en_core_awake = FIELD_EX32(value, AON_WDT_WDOGCFG, EN_CORE_AWAKE); + old_en_always = FIELD_EX32(r->wdogcfg, AON_WDT_WDOGCFG, EN_ALWAYS); + old_en_core_awake = FIELD_EX32(r->wdogcfg, AON_WDT_WDOGCFG, + EN_CORE_AWAKE); + + if ((old_en_always || + old_en_core_awake) == 1 && + (new_en_always || + new_en_core_awake) == 0) { + sifive_e_aon_wdt_update_wdogcount(r); + } else if ((old_en_always || + old_en_core_awake) == 0 && + (new_en_always || + new_en_core_awake) == 1) { + r->wdog_restart_time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); + } + r->wdogcfg = value; + r->wdogunlock = 0; + break; + } + case A_AON_WDT_WDOGCOUNT: + if (r->wdogunlock == 0) { + return; + } + r->wdogcount = value & R_AON_WDT_WDOGCOUNT_VALUE_MASK; + r->wdog_restart_time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); + r->wdogunlock = 0; + break; + case A_AON_WDT_WDOGS: + return; + case A_AON_WDT_WDOGFEED: + if (r->wdogunlock == 0) { + return; + } + if (value == SIFIVE_E_AON_WDOGFEED) { + r->wdogcount = 0; + r->wdog_restart_time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); + } + r->wdogunlock = 0; + break; + case A_AON_WDT_WDOGKEY: + if (value == SIFIVE_E_AON_WDOGKEY) { + r->wdogunlock = 1; + } + break; + case A_AON_WDT_WDOGCMP0: + if (r->wdogunlock == 0) { + return; + } + r->wdogcmp0 = (uint16_t) value; + r->wdogunlock = 0; + break; + default: + qemu_log_mask(LOG_GUEST_ERROR, "%s: bad write: addr=0x%x v=0x%x\n", + __func__, (int)addr, (int)value); + } + sifive_e_aon_wdt_update_state(r); +} + +static uint64_t +sifive_e_aon_read(void *opaque, hwaddr addr, unsigned int size) +{ + if (addr < SIFIVE_E_AON_RTC) { + return sifive_e_aon_wdt_read(opaque, addr, size); + } else if (addr < SIFIVE_E_AON_MAX) { + qemu_log_mask(LOG_UNIMP, "%s: Unimplemented read: addr=0x%x\n", + __func__, (int)addr); + } else { + qemu_log_mask(LOG_GUEST_ERROR, "%s: bad read: addr=0x%x\n", + __func__, (int)addr); + } + return 0; +} + +static void +sifive_e_aon_write(void *opaque, hwaddr addr, + uint64_t val64, unsigned int size) +{ + if (addr < SIFIVE_E_AON_RTC) { + sifive_e_aon_wdt_write(opaque, addr, val64, size); + } else if (addr < SIFIVE_E_AON_MAX) { + qemu_log_mask(LOG_UNIMP, "%s: Unimplemented write: addr=0x%x\n", + __func__, (int)addr); + } else { + qemu_log_mask(LOG_GUEST_ERROR, "%s: bad write: addr=0x%x\n", + __func__, (int)addr); + } +} + +static const MemoryRegionOps sifive_e_aon_ops = { + .read = sifive_e_aon_read, + .write = sifive_e_aon_write, + .endianness = DEVICE_NATIVE_ENDIAN, + .impl = { + .min_access_size = 4, + .max_access_size = 4 + }, + .valid = { + .min_access_size = 4, + .max_access_size = 4 + } +}; + +static void sifive_e_aon_reset(DeviceState *dev) +{ + SiFiveEAONState *r = SIFIVE_E_AON(dev); + + r->wdogcfg = FIELD_DP32(r->wdogcfg, AON_WDT_WDOGCFG, RSTEN, 0); + r->wdogcfg = FIELD_DP32(r->wdogcfg, AON_WDT_WDOGCFG, EN_ALWAYS, 0); + r->wdogcfg = FIELD_DP32(r->wdogcfg, AON_WDT_WDOGCFG, EN_CORE_AWAKE, 0); + r->wdogcmp0 = 0xbeef; + + sifive_e_aon_wdt_update_state(r); +} + +static void sifive_e_aon_init(Object *obj) +{ + SysBusDevice *sbd = SYS_BUS_DEVICE(obj); + SiFiveEAONState *r = SIFIVE_E_AON(obj); + + memory_region_init_io(&r->mmio, OBJECT(r), &sifive_e_aon_ops, r, + TYPE_SIFIVE_E_AON, SIFIVE_E_AON_MAX); + sysbus_init_mmio(sbd, &r->mmio); + + /* watchdog timer */ + r->wdog_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, + sifive_e_aon_wdt_expired_cb, r); + r->wdogclk_freq = SIFIVE_E_LFCLK_DEFAULT_FREQ; + sysbus_init_irq(sbd, &r->wdog_irq); +} + +static Property sifive_e_aon_properties[] = { + DEFINE_PROP_UINT64("wdogclk-frequency", SiFiveEAONState, wdogclk_freq, + SIFIVE_E_LFCLK_DEFAULT_FREQ), + DEFINE_PROP_END_OF_LIST(), +}; + +static void sifive_e_aon_class_init(ObjectClass *oc, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(oc); + + dc->reset = sifive_e_aon_reset; + device_class_set_props(dc, sifive_e_aon_properties); +} + +static const TypeInfo sifive_e_aon_info = { + .name = TYPE_SIFIVE_E_AON, + .parent = TYPE_SYS_BUS_DEVICE, + .instance_size = sizeof(SiFiveEAONState), + .instance_init = sifive_e_aon_init, + .class_init = sifive_e_aon_class_init, +}; + +static void sifive_e_aon_register_types(void) +{ + type_register_static(&sifive_e_aon_info); +} + +type_init(sifive_e_aon_register_types) diff --git a/hw/misc/Kconfig b/hw/misc/Kconfig index e4c2149175..6996d265e4 100644 --- a/hw/misc/Kconfig +++ b/hw/misc/Kconfig @@ -158,6 +158,9 @@ config SIFIVE_TEST config SIFIVE_E_PRCI bool +config SIFIVE_E_AON + bool + config SIFIVE_U_OTP bool diff --git a/hw/misc/meson.build b/hw/misc/meson.build index 05877f61cc..892f8b91c5 100644 --- a/hw/misc/meson.build +++ b/hw/misc/meson.build @@ -30,6 +30,7 @@ system_ss.add(when: 'CONFIG_MCHP_PFSOC_IOSCB', if_true: files('mchp_pfsoc_ioscb. system_ss.add(when: 'CONFIG_MCHP_PFSOC_SYSREG', if_true: files('mchp_pfsoc_sysreg.c')) system_ss.add(when: 'CONFIG_SIFIVE_TEST', if_true: files('sifive_test.c')) system_ss.add(when: 'CONFIG_SIFIVE_E_PRCI', if_true: files('sifive_e_prci.c')) +system_ss.add(when: 'CONFIG_SIFIVE_E_AON', if_true: files('sifive_e_aon.c')) system_ss.add(when: 'CONFIG_SIFIVE_U_OTP', if_true: files('sifive_u_otp.c')) system_ss.add(when: 'CONFIG_SIFIVE_U_PRCI', if_true: files('sifive_u_prci.c'))