From mboxrd@z Thu Jan 1 00:00:00 1970 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 035AEC433FE for ; Fri, 18 Nov 2022 13:58:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242033AbiKRN66 (ORCPT ); Fri, 18 Nov 2022 08:58:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42482 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241523AbiKRN6y (ORCPT ); Fri, 18 Nov 2022 08:58:54 -0500 Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F27196261; Fri, 18 Nov 2022 05:58:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1668779933; x=1700315933; h=date:from:to:cc:subject:in-reply-to:message-id: references:mime-version; bh=nShZpoZFoRHWgmSg5gh/suMCBijJSZAQGCwKIphVewU=; b=ZzXyt/H28ZUXAx50wKeRUJFhbhAHANkj3EjrEUvrwcxHG/G+gkd8OvH9 Jnv8SV+Uv0sbMgM1xEnuL62fQ/hCziI/WFZsNuCeJQWQ6iNgRoUrS8uaR GLfXCDSWbhwAZ0BjQIQsA3H6CdeScSFFV28odmT1rB5kfXqExTPjfRtJL RgbCJfryb1hpCnf2Dd4V+HWi/nZicVSCZ5W1piHRPPGVX2pGzGDzFWZ7I c+w3894D1ZXeprU6KN3J2dsYm+KoeTlXXn6Rplz7vEBolP00KRofHkRxy zuiqUM+dhU9f3nPhTsNAEG9PwPxQ88FS7pk54yoVy0PxfqG1OdPS6pZ7d A==; X-IronPort-AV: E=McAfee;i="6500,9779,10535"; a="375271128" X-IronPort-AV: E=Sophos;i="5.96,174,1665471600"; d="scan'208";a="375271128" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Nov 2022 05:58:52 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10535"; a="640217830" X-IronPort-AV: E=Sophos;i="5.96,174,1665471600"; d="scan'208";a="640217830" Received: from amulyuko-mobl1.ccr.corp.intel.com ([10.252.35.83]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Nov 2022 05:58:49 -0800 Date: Fri, 18 Nov 2022 15:58:47 +0200 (EET) From: =?ISO-8859-15?Q?Ilpo_J=E4rvinen?= To: Gabriel Somlo cc: LKML , linux-serial , Greg Kroah-Hartman , Jiri Slaby , kgugala@antmicro.com, mholenko@antmicro.com, joel@jms.id.au, david.abdurachmanov@gmail.com, florent@enjoy-digital.fr, geert@linux-m68k.org Subject: Re: [PATCH v4 12/14] serial: liteuart: add IRQ support for the RX path In-Reply-To: <20221116144908.234154-13-gsomlo@gmail.com> Message-ID: <6629539b-c5a7-4edc-7ab1-5c977f7319@linux.intel.com> References: <20221116144908.234154-1-gsomlo@gmail.com> <20221116144908.234154-13-gsomlo@gmail.com> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="8323329-651772109-1668779933=:3952" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323329-651772109-1668779933=:3952 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 8BIT On Wed, 16 Nov 2022, Gabriel Somlo wrote: > Add support for IRQ-driven RX. Support for the TX path will be added > in a separate commit. > > Signed-off-by: Gabriel Somlo > --- > > Changes from v3: > - add shadow irq register to support polling mode and avoid reading > hardware mmio irq register to learn which irq flags are enabled > - this also simplifies both liteuart_interrupt() and liteuart_startup() > > drivers/tty/serial/liteuart.c | 76 +++++++++++++++++++++++++++++++---- > 1 file changed, 69 insertions(+), 7 deletions(-) > > diff --git a/drivers/tty/serial/liteuart.c b/drivers/tty/serial/liteuart.c > index 8a6e176be08e..fad778578986 100644 > --- a/drivers/tty/serial/liteuart.c > +++ b/drivers/tty/serial/liteuart.c > @@ -7,6 +7,7 @@ > > #include > #include > +#include > #include > #include > #include > @@ -46,6 +47,7 @@ struct liteuart_port { > struct uart_port port; > struct timer_list timer; > u32 id; > + u8 irq_reg; > }; > > #define to_liteuart_port(port) container_of(port, struct liteuart_port, port) > @@ -76,6 +78,19 @@ static void liteuart_putchar(struct uart_port *port, unsigned char ch) > litex_write8(port->membase + OFF_RXTX, ch); > } > > +static void liteuart_update_irq_reg(struct uart_port *port, bool set, u8 mask) > +{ > + struct liteuart_port *uart = to_liteuart_port(port); > + > + if (set) > + uart->irq_reg |= mask; > + else > + uart->irq_reg &= ~mask; > + > + if (port->irq) > + litex_write8(port->membase + OFF_EV_ENABLE, uart->irq_reg); > +} > + > static void liteuart_stop_tx(struct uart_port *port) > { > } > @@ -129,13 +144,27 @@ static void liteuart_rx_chars(struct uart_port *port) > tty_flip_buffer_push(&port->state->port); > } > > +static irqreturn_t liteuart_interrupt(int irq, void *data) > +{ > + struct liteuart_port *uart = data; > + struct uart_port *port = &uart->port; > + u8 isr; > + > + spin_lock(&port->lock); > + isr = litex_read8(port->membase + OFF_EV_PENDING) & uart->irq_reg; > + if (isr & EV_RX) > + liteuart_rx_chars(port); > + spin_unlock(&port->lock); > + > + return IRQ_RETVAL(isr); > +} > + > static void liteuart_timer(struct timer_list *t) > { > struct liteuart_port *uart = from_timer(uart, t, timer); > struct uart_port *port = &uart->port; > > - liteuart_rx_chars(port); > - > + liteuart_interrupt(0, port); > mod_timer(&uart->timer, jiffies + uart_poll_timeout(port)); > } > > @@ -161,19 +190,45 @@ static unsigned int liteuart_get_mctrl(struct uart_port *port) > static int liteuart_startup(struct uart_port *port) > { > struct liteuart_port *uart = to_liteuart_port(port); > + unsigned long flags; > + int ret; > > - /* disable events */ > - litex_write8(port->membase + OFF_EV_ENABLE, 0); > + if (port->irq) { > + ret = request_irq(port->irq, liteuart_interrupt, 0, > + KBUILD_MODNAME, uart); > + if (ret) { > + pr_err(pr_fmt("line %d irq %d failed: using polling\n"), > + port->line, port->irq); dev_err() seems more appropriate here. > + port->irq = 0; > + } > + } > > - /* prepare timer for polling */ > - timer_setup(&uart->timer, liteuart_timer, 0); > - mod_timer(&uart->timer, jiffies + uart_poll_timeout(port)); > + spin_lock_irqsave(&port->lock, flags); > + /* only enabling rx irqs during startup */ > + liteuart_update_irq_reg(port, true, EV_RX); > + spin_unlock_irqrestore(&port->lock, flags); > + > + if (!port->irq) { > + timer_setup(&uart->timer, liteuart_timer, 0); > + mod_timer(&uart->timer, jiffies + uart_poll_timeout(port)); > + } > > return 0; > } > > static void liteuart_shutdown(struct uart_port *port) > { > + struct liteuart_port *uart = to_liteuart_port(port); > + unsigned long flags; > + > + spin_lock_irqsave(&port->lock, flags); > + liteuart_update_irq_reg(port, false, EV_RX | EV_TX); > + spin_unlock_irqrestore(&port->lock, flags); > + > + if (port->irq) > + free_irq(port->irq, port); > + else > + del_timer_sync(&uart->timer); > } > > static void liteuart_set_termios(struct uart_port *port, struct ktermios *new, > @@ -262,6 +317,13 @@ static int liteuart_probe(struct platform_device *pdev) > goto err_erase_id; > } > > + /* get irq */ This comment is unnecessary. Other than that, Reviewed-by: Ilpo Järvinen -- i. > + ret = platform_get_irq_optional(pdev, 0); > + if (ret < 0 && ret != -ENXIO) > + return ret; > + if (ret > 0) > + port->irq = ret; > + > /* values not from device tree */ > port->dev = &pdev->dev; > port->iotype = UPIO_MEM; > --8323329-651772109-1668779933=:3952--