From patchwork Thu May 14 09:45:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andre Przywara X-Patchwork-Id: 11548415 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 84E19739 for ; Thu, 14 May 2020 09:46:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6EA5F206B6 for ; Thu, 14 May 2020 09:46:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725976AbgENJqA (ORCPT ); Thu, 14 May 2020 05:46:00 -0400 Received: from foss.arm.com ([217.140.110.172]:33318 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725878AbgENJqA (ORCPT ); Thu, 14 May 2020 05:46:00 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A886431B; Thu, 14 May 2020 02:45:59 -0700 (PDT) Received: from donnerap.arm.com (donnerap.cambridge.arm.com [10.1.197.25]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id ACFCA3F305; Thu, 14 May 2020 02:45:58 -0700 (PDT) From: Andre Przywara To: Will Deacon , Julien Thierry Cc: Sami Mujawar , Alexandru Elisei , kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu Subject: [PATCH kvmtool] rtc: Generate fdt node for the real-time clock Date: Thu, 14 May 2020 10:45:53 +0100 Message-Id: <20200514094553.135663-1-andre.przywara@arm.com> X-Mailer: git-send-email 2.17.1 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On arm and arm64 we expose the Motorola RTC emulation to the guest, but never advertised this in the device tree. EDK-2 seems to rely on this device, but on its hardcoded address. To make this more future-proof, add a DT node with the address in it. EDK-2 can then read the proper address from there, and we can change this address later (with the flexible memory layout). Please note that an arm64 Linux kernel is not ready to use this device, there are some include files missing under arch/arm64 to compile the driver. I hacked this up in the kernel, just to verify this DT snippet is correct, but don't see much value in enabling this properly in Linux. Signed-off-by: Andre Przywara --- hw/rtc.c | 44 ++++++++++++++++++++++++++++++++++++++------ 1 file changed, 38 insertions(+), 6 deletions(-) diff --git a/hw/rtc.c b/hw/rtc.c index c1fa72f2..5483879f 100644 --- a/hw/rtc.c +++ b/hw/rtc.c @@ -130,24 +130,56 @@ static struct ioport_operations cmos_ram_index_ioport_ops = { .io_out = cmos_ram_index_out, }; +#ifdef CONFIG_HAS_LIBFDT +static void generate_rtc_fdt_node(void *fdt, + struct device_header *dev_hdr, + void (*generate_irq_prop)(void *fdt, + u8 irq, + enum irq_type)) +{ + u64 reg_prop[2] = { cpu_to_fdt64(0x70), cpu_to_fdt64(2) }; + + _FDT(fdt_begin_node(fdt, "rtc")); + _FDT(fdt_property_string(fdt, "compatible", "motorola,mc146818")); + _FDT(fdt_property(fdt, "reg", reg_prop, sizeof(reg_prop))); + _FDT(fdt_end_node(fdt)); +} +#else +#define generate_rtc_fdt_node NULL +#endif + +struct device_header rtc_dev_hdr = { + .bus_type = DEVICE_BUS_IOPORT, + .data = generate_rtc_fdt_node, +}; + int rtc__init(struct kvm *kvm) { - int r = 0; + int r; + + r = device__register(&rtc_dev_hdr); + if (r < 0) + return r; /* PORT 0070-007F - CMOS RAM/RTC (REAL TIME CLOCK) */ r = ioport__register(kvm, 0x0070, &cmos_ram_index_ioport_ops, 1, NULL); if (r < 0) - return r; + goto out_device; r = ioport__register(kvm, 0x0071, &cmos_ram_data_ioport_ops, 1, NULL); - if (r < 0) { - ioport__unregister(kvm, 0x0071); - return r; - } + if (r < 0) + goto out_ioport; /* Set the VRT bit in Register D to indicate valid RAM and time */ rtc.cmos_data[RTC_REG_D] = RTC_REG_D_VRT; + return r; + +out_ioport: + ioport__unregister(kvm, 0x0070); +out_device: + device__unregister(&rtc_dev_hdr); + return r; } dev_init(rtc__init);