From patchwork Wed Nov 24 07:46:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hector Martin X-Patchwork-Id: 517568 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 C9375C433F5 for ; Wed, 24 Nov 2021 07:47:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240192AbhKXHuO (ORCPT ); Wed, 24 Nov 2021 02:50:14 -0500 Received: from marcansoft.com ([212.63.210.85]:55730 "EHLO mail.marcansoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229482AbhKXHuN (ORCPT ); Wed, 24 Nov 2021 02:50:13 -0500 Received: from [127.0.0.1] (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: hector@marcansoft.com) by mail.marcansoft.com (Postfix) with ESMTPSA id 1615E41E57; Wed, 24 Nov 2021 07:46:57 +0000 (UTC) From: Hector Martin To: linux-arm-kernel@lists.infradead.org Cc: Hector Martin , Marc Zyngier , Rob Herring , Arnd Bergmann , Linus Walleij , Alyssa Rosenzweig , Krzysztof Kozlowski , Greg Kroah-Hartman , Mark Kettenis , Philipp Zabel , "Rafael J. Wysocki" , Johan Hovold , devicetree@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-serial@vger.kernel.org Subject: [PATCH v3 10/11] tty: serial: samsung_tty: Support runtime PM Date: Wed, 24 Nov 2021 16:46:24 +0900 Message-Id: <20211124074625.182815-11-marcan@marcan.st> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211124073419.181799-1-marcan@marcan.st> References: <20211124073419.181799-1-marcan@marcan.st> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org This allows idle UART devices to be suspended using the standard runtime-PM framework. The logic is modeled after stm32-usart. Signed-off-by: Hector Martin Acked-by: Krzysztof Kozlowski --- drivers/tty/serial/samsung_tty.c | 93 ++++++++++++++++++++------------ 1 file changed, 59 insertions(+), 34 deletions(-) diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c index ca084c10d0bb..75c87d7240d9 100644 --- a/drivers/tty/serial/samsung_tty.c +++ b/drivers/tty/serial/samsung_tty.c @@ -40,6 +40,7 @@ #include #include #include +#include #include /* UART name and device definitions */ @@ -1381,31 +1382,49 @@ static void exynos_usi_init(struct uart_port *port) /* power power management control */ -static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level, - unsigned int old) +static int __maybe_unused s3c24xx_serial_runtime_suspend(struct device *dev) { + struct uart_port *port = dev_get_drvdata(dev); struct s3c24xx_uart_port *ourport = to_ourport(port); int timeout = 10000; - ourport->pm_level = level; + while (--timeout && !s3c24xx_serial_txempty_nofifo(port)) + udelay(100); - switch (level) { - case 3: - while (--timeout && !s3c24xx_serial_txempty_nofifo(port)) - udelay(100); + if (!IS_ERR(ourport->baudclk)) + clk_disable_unprepare(ourport->baudclk); - if (!IS_ERR(ourport->baudclk)) - clk_disable_unprepare(ourport->baudclk); + clk_disable_unprepare(ourport->clk); + return 0; +}; - clk_disable_unprepare(ourport->clk); - break; +static int __maybe_unused s3c24xx_serial_runtime_resume(struct device *dev) +{ + struct uart_port *port = dev_get_drvdata(dev); + struct s3c24xx_uart_port *ourport = to_ourport(port); - case 0: - clk_prepare_enable(ourport->clk); + clk_prepare_enable(ourport->clk); - if (!IS_ERR(ourport->baudclk)) - clk_prepare_enable(ourport->baudclk); + if (!IS_ERR(ourport->baudclk)) + clk_prepare_enable(ourport->baudclk); + return 0; +}; +static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level, + unsigned int old) +{ + struct s3c24xx_uart_port *ourport = to_ourport(port); + + ourport->pm_level = level; + + switch (level) { + case UART_PM_STATE_OFF: + pm_runtime_mark_last_busy(port->dev); + pm_runtime_put_sync(port->dev); + break; + + case UART_PM_STATE_ON: + pm_runtime_get_sync(port->dev); exynos_usi_init(port); break; default: @@ -2282,18 +2301,15 @@ static int s3c24xx_serial_probe(struct platform_device *pdev) } } + pm_runtime_get_noresume(&pdev->dev); + pm_runtime_set_active(&pdev->dev); + pm_runtime_enable(&pdev->dev); + dev_dbg(&pdev->dev, "%s: adding port\n", __func__); uart_add_one_port(&s3c24xx_uart_drv, &ourport->port); platform_set_drvdata(pdev, &ourport->port); - /* - * Deactivate the clock enabled in s3c24xx_serial_init_port here, - * so that a potential re-enablement through the pm-callback overlaps - * and keeps the clock enabled in this case. - */ - clk_disable_unprepare(ourport->clk); - if (!IS_ERR(ourport->baudclk)) - clk_disable_unprepare(ourport->baudclk); + pm_runtime_put_sync(&pdev->dev); ret = s3c24xx_serial_cpufreq_register(ourport); if (ret < 0) @@ -2307,10 +2323,21 @@ static int s3c24xx_serial_probe(struct platform_device *pdev) static int s3c24xx_serial_remove(struct platform_device *dev) { struct uart_port *port = s3c24xx_dev_to_port(&dev->dev); + struct s3c24xx_uart_port *ourport = to_ourport(port); if (port) { + pm_runtime_get_sync(&dev->dev); + s3c24xx_serial_cpufreq_deregister(to_ourport(port)); uart_remove_one_port(&s3c24xx_uart_drv, port); + + clk_disable_unprepare(ourport->clk); + if (!IS_ERR(ourport->baudclk)) + clk_disable_unprepare(ourport->baudclk); + + pm_runtime_disable(&dev->dev); + pm_runtime_set_suspended(&dev->dev); + pm_runtime_put_noidle(&dev->dev); } uart_unregister_driver(&s3c24xx_uart_drv); @@ -2319,8 +2346,8 @@ static int s3c24xx_serial_remove(struct platform_device *dev) } /* UART power management code */ -#ifdef CONFIG_PM_SLEEP -static int s3c24xx_serial_suspend(struct device *dev) + +static int __maybe_unused s3c24xx_serial_suspend(struct device *dev) { struct uart_port *port = s3c24xx_dev_to_port(dev); @@ -2330,7 +2357,7 @@ static int s3c24xx_serial_suspend(struct device *dev) return 0; } -static int s3c24xx_serial_resume(struct device *dev) +static int __maybe_unused s3c24xx_serial_resume(struct device *dev) { struct uart_port *port = s3c24xx_dev_to_port(dev); struct s3c24xx_uart_port *ourport = to_ourport(port); @@ -2350,7 +2377,7 @@ static int s3c24xx_serial_resume(struct device *dev) return 0; } -static int s3c24xx_serial_resume_noirq(struct device *dev) +static int __maybe_unused s3c24xx_serial_resume_noirq(struct device *dev) { struct uart_port *port = s3c24xx_dev_to_port(dev); struct s3c24xx_uart_port *ourport = to_ourport(port); @@ -2420,16 +2447,14 @@ static int s3c24xx_serial_resume_noirq(struct device *dev) } static const struct dev_pm_ops s3c24xx_serial_pm_ops = { +#ifdef CONFIG_PM_SLEEP .suspend = s3c24xx_serial_suspend, .resume = s3c24xx_serial_resume, .resume_noirq = s3c24xx_serial_resume_noirq, +#endif + SET_RUNTIME_PM_OPS(s3c24xx_serial_runtime_suspend, + s3c24xx_serial_runtime_resume, NULL) }; -#define SERIAL_SAMSUNG_PM_OPS (&s3c24xx_serial_pm_ops) - -#else /* !CONFIG_PM_SLEEP */ - -#define SERIAL_SAMSUNG_PM_OPS NULL -#endif /* CONFIG_PM_SLEEP */ /* Console code */ @@ -2921,7 +2946,7 @@ static struct platform_driver samsung_serial_driver = { .id_table = s3c24xx_serial_driver_ids, .driver = { .name = "samsung-uart", - .pm = SERIAL_SAMSUNG_PM_OPS, + .pm = &s3c24xx_serial_pm_ops, .of_match_table = of_match_ptr(s3c24xx_uart_dt_match), }, };