From patchwork Thu Jan 23 05:25:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guenter Roeck X-Patchwork-Id: 11346775 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 3F3F46C1 for ; Thu, 23 Jan 2020 05:33:11 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 156CB24676 for ; Thu, 23 Jan 2020 05:33:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="QdPVjOxM" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 156CB24676 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=roeck-us.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:51244 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iuV78-00053o-66 for patchwork-qemu-devel@patchwork.kernel.org; Thu, 23 Jan 2020 00:33:10 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:42290) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iuV0I-0004wY-G8 for qemu-devel@nongnu.org; Thu, 23 Jan 2020 00:26:07 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iuV0G-0001rl-ST for qemu-devel@nongnu.org; Thu, 23 Jan 2020 00:26:06 -0500 Received: from mail-pg1-x541.google.com ([2607:f8b0:4864:20::541]:39545) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1iuV0B-0001pK-MX; Thu, 23 Jan 2020 00:25:59 -0500 Received: by mail-pg1-x541.google.com with SMTP id 4so771213pgd.6; Wed, 22 Jan 2020 21:25:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references; bh=KeM+UcLJ0eZCHHeipWPmwwPiaN02ZhSI49JMqf9Y4mU=; b=QdPVjOxMhYXoon6u89PhZsZHpR/3WcQt09Zpc622s6LKjlcfYF4f8wOyY/ORFw4XdH cPjfeEtwD4msjL0lJGc2SDWESk65+UqKvK6j95RIO2KCQbWS7M6UoV622lVPKteDoG0m lSSff/8issKkvZcP4W49YLPytK7zrKiBKPB3M8q3AUCfaIyaqtvZ1frEzYhD0DlkmxsE dYiDy7u+lDyg4Nc0+5M4AjFVrT/FxxJkiZk8pPE3YvQoxBK/lySnaogcR5/Hp/tv7zqi FXTObFRH3T2J6jP0IqdqKDlbh7Fh3JD21oLbpGdQQbh5tlGvt8S2hrV/Zu1twWGDH7QW p5iQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references; bh=KeM+UcLJ0eZCHHeipWPmwwPiaN02ZhSI49JMqf9Y4mU=; b=gNDoFNmTDNJ53We4yUNu3k3L4zzpOs5e4PApPDyqvcpBkRo7IAUv9SEO3iTSfYCCNV BlTE00VXUHmPetLmNVWPpaavm2GbbQvXu/8LbsDkLy5JoB5ottLfIRhh6cEVIxZ97S0I 2jjoTelo8+pzvWkpSxo/z/R1EiyTqfc8htNSplEw8lm/j96sNPu+I5Yyy43yEZeLvhKe Iyyq1TNmZ/PSGHj0FGnhkRuX3C2ngZBrZS9u/tzZEEUpZFH8XscwBDbsM/upEeDBXAic CxuGIa0g/OpKwJaTRAZjJHR9HQoZHuB0oVn/0m+cM8o9lT4Y/t6IU2kZjAXc8MccmoFB 7pJA== X-Gm-Message-State: APjAAAXRHrDPI1PgiitQ+amvsB3FJlEtNoeakeiMrUHhvoltG8pavo+D S8uYfAptP4G88qtRcSQziHU= X-Google-Smtp-Source: APXvYqzoIdeEopZGCNkFFwLebtJ4ETGdRWYwX2xufS5RIjnhRAbP7q4Q9sJp4wwQJcifKb5UBvYdrg== X-Received: by 2002:a62:83c5:: with SMTP id h188mr5963479pfe.0.1579757157542; Wed, 22 Jan 2020 21:25:57 -0800 (PST) Received: from localhost ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id 17sm730160pfv.142.2020.01.22.21.25.56 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 22 Jan 2020 21:25:57 -0800 (PST) From: Guenter Roeck To: Peter Maydell Subject: [PATCH v3 7/8] hw/char/exynos4210_uart: Add receive DMA support Date: Wed, 22 Jan 2020 21:25:39 -0800 Message-Id: <20200123052540.6132-8-linux@roeck-us.net> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200123052540.6132-1-linux@roeck-us.net> References: <20200123052540.6132-1-linux@roeck-us.net> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2607:f8b0:4864:20::541 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paolo Bonzini , qemu-arm@nongnu.org, qemu-devel@nongnu.org, Guenter Roeck Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" To support receive DMA, we need to inform the DMA controller if receive data is available. Otherwise the DMA controller keeps requesting data, causing receive errors. Implement this using an interrupt line. The instantiating code then needs to connect the interrupt with the matching DMA controller GPIO pin. Reviewed-by: Peter Maydell Signed-off-by: Guenter Roeck --- v3: No change v2: Added Reviewed-by: tag hw/char/exynos4210_uart.c | 24 ++++++++++++++++++++++++ hw/char/trace-events | 2 ++ 2 files changed, 26 insertions(+) diff --git a/hw/char/exynos4210_uart.c b/hw/char/exynos4210_uart.c index 8d6b4a071e..bf9e586e79 100644 --- a/hw/char/exynos4210_uart.c +++ b/hw/char/exynos4210_uart.c @@ -154,6 +154,7 @@ typedef struct Exynos4210UartState { CharBackend chr; qemu_irq irq; + qemu_irq dmairq; uint32_t channel; @@ -261,6 +262,24 @@ exynos4210_uart_Rx_FIFO_trigger_level(const Exynos4210UartState *s) return exynos4210_uart_FIFO_trigger_level(s->channel, reg); } +/* + * Update Rx DMA busy signal if Rx DMA is enabled. For simplicity, + * mark DMA as busy if DMA is enabled and the receive buffer is empty. + */ +static void exynos4210_uart_update_dmabusy(Exynos4210UartState *s) +{ + bool rx_dma_enabled = (s->reg[I_(UCON)] & 0x03) == 0x02; + uint32_t count = fifo_elements_number(&s->rx); + + if (rx_dma_enabled && !count) { + qemu_irq_raise(s->dmairq); + trace_exynos_uart_dmabusy(s->channel); + } else { + qemu_irq_lower(s->dmairq); + trace_exynos_uart_dmaready(s->channel); + } +} + static void exynos4210_uart_update_irq(Exynos4210UartState *s) { /* @@ -282,10 +301,12 @@ static void exynos4210_uart_update_irq(Exynos4210UartState *s) count = fifo_elements_number(&s->rx); if ((count && !(s->reg[I_(UCON)] & 0x80)) || count >= exynos4210_uart_Rx_FIFO_trigger_level(s)) { + exynos4210_uart_update_dmabusy(s); s->reg[I_(UINTSP)] |= UINTSP_RXD; timer_del(s->fifo_timeout_timer); } } else if (s->reg[I_(UTRSTAT)] & UTRSTAT_Rx_BUFFER_DATA_READY) { + exynos4210_uart_update_dmabusy(s); s->reg[I_(UINTSP)] |= UINTSP_RXD; } @@ -311,6 +332,7 @@ static void exynos4210_uart_timeout_int(void *opaque) (s->reg[I_(UCON)] & (1 << 11))) { s->reg[I_(UINTSP)] |= UINTSP_RXD; s->reg[I_(UTRSTAT)] |= UTRSTAT_Rx_TIMEOUT; + exynos4210_uart_update_dmabusy(s); exynos4210_uart_update_irq(s); } } @@ -495,6 +517,7 @@ static uint64_t exynos4210_uart_read(void *opaque, hwaddr offset, s->reg[I_(UTRSTAT)] &= ~UTRSTAT_Rx_BUFFER_DATA_READY; res = s->reg[I_(URXH)]; } + exynos4210_uart_update_dmabusy(s); trace_exynos_uart_read(s->channel, offset, exynos4210_uart_regname(offset), res); return res; @@ -661,6 +684,7 @@ static void exynos4210_uart_init(Object *obj) sysbus_init_mmio(dev, &s->iomem); sysbus_init_irq(dev, &s->irq); + sysbus_init_irq(dev, &s->dmairq); } static void exynos4210_uart_realize(DeviceState *dev, Error **errp) diff --git a/hw/char/trace-events b/hw/char/trace-events index cb73fee6a9..6f938301d9 100644 --- a/hw/char/trace-events +++ b/hw/char/trace-events @@ -79,6 +79,8 @@ nrf51_uart_read(uint64_t addr, uint64_t r, unsigned int size) "addr 0x%" PRIx64 nrf51_uart_write(uint64_t addr, uint64_t value, unsigned int size) "addr 0x%" PRIx64 " value 0x%" PRIx64 " size %u" # exynos4210_uart.c +exynos_uart_dmabusy(uint32_t channel) "UART%d: DMA busy (Rx buffer empty)" +exynos_uart_dmaready(uint32_t channel) "UART%d: DMA ready" exynos_uart_irq_raised(uint32_t channel, uint32_t reg) "UART%d: IRQ raised: 0x%08"PRIx32 exynos_uart_irq_lowered(uint32_t channel) "UART%d: IRQ lowered" exynos_uart_update_params(uint32_t channel, int speed, uint8_t parity, int data, int stop, uint64_t wordtime) "UART%d: speed: %d, parity: %c, data bits: %d, stop bits: %d wordtime: %"PRId64"ns"