From patchwork Thu Aug 9 21:43:58 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Cercueil X-Patchwork-Id: 955818 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-pwm-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=crapouillou.net Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=crapouillou.net header.i=@crapouillou.net header.b="q7KaSFec"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 41mhfC20T2z9s3Z for ; Fri, 10 Aug 2018 07:46:27 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727619AbeHJALv (ORCPT ); Thu, 9 Aug 2018 20:11:51 -0400 Received: from outils.crapouillou.net ([89.234.176.41]:59874 "EHLO crapouillou.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727601AbeHJALu (ORCPT ); Thu, 9 Aug 2018 20:11:50 -0400 From: Paul Cercueil To: Rob Herring , Mark Rutland , Thierry Reding , Daniel Lezcano , Thomas Gleixner , Wim Van Sebroeck , Guenter Roeck , Ralf Baechle , Paul Burton , James Hogan , Jonathan Corbet , Lee Jones , Mathieu Malaterre , Ezequiel Garcia Cc: linux-pwm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-mips@linux-mips.org, linux-doc@vger.kernel.org, linux-clk@vger.kernel.org, Paul Cercueil Subject: [PATCH v6 08/24] watchdog: jz4740: Use WDT clock provided by TCU driver Date: Thu, 9 Aug 2018 23:43:58 +0200 Message-Id: <20180809214414.20905-9-paul@crapouillou.net> In-Reply-To: <20180809214414.20905-1-paul@crapouillou.net> References: <20180809214414.20905-1-paul@crapouillou.net> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=crapouillou.net; s=mail; t=1533851101; bh=hIy5cSWAS6P1ctW8+k/l89HhdWCU7zPoVRTMU02qJfo=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References; b=q7KaSFec2KDsQpgK5U7XYtMMNSO6TQnxDnZkGYr0NiGDgKbuW+wGkmzPB5XOT4iS29TsGdWtic6qKzKApzST5qAiKZL7kr8OwcVzzSYW10mY+ZfEwfgP8IYg59VGoky7QrByHwbOW/ts5Z+5cnZS0hWsRIRIMKviJTWiWMDjE/k= Sender: linux-pwm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pwm@vger.kernel.org Instead of requesting the "ext" clock and handling the watchdog clock divider and gating in the watchdog driver, we now request and use the "wdt" clock that is supplied by the ingenic-timer "TCU" driver. The major benefit is that the watchdog's clock rate and parent can now be specified from within devicetree, instead of hardcoded in the driver. Also, this driver won't poke anymore into the TCU registers to enable/disable the clock, as this is now handled by the TCU driver. On the bad side, we break the ABI with devicetree - as we now request a different clock. In this very specific case it is still okay, as every Ingenic JZ47xx-based board out there compile the devicetree within the kernel; so it's still time to push breaking changes, in order to get a clean devicetree that won't break once it musn't. Signed-off-by: Paul Cercueil Reviewed-by: Guenter Roeck --- drivers/watchdog/Kconfig | 2 + drivers/watchdog/jz4740_wdt.c | 86 +++++++++++++++++-------------------------- 2 files changed, 36 insertions(+), 52 deletions(-) v5: New patch v6: - Split regmap change to new patch 09/24 - The code now sets the WDT clock to the smallest rate possible and calculates the maximum timeout from that diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 9af07fd92763..834222abbbdb 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1476,7 +1476,9 @@ config INDYDOG config JZ4740_WDT tristate "Ingenic jz4740 SoC hardware watchdog" depends on MACH_JZ4740 || MACH_JZ4780 + depends on COMMON_CLK select WATCHDOG_CORE + select INGENIC_TIMER help Hardware driver for the built-in watchdog timer on Ingenic jz4740 SoCs. diff --git a/drivers/watchdog/jz4740_wdt.c b/drivers/watchdog/jz4740_wdt.c index ec4d99a830ba..1d504ecf45e1 100644 --- a/drivers/watchdog/jz4740_wdt.c +++ b/drivers/watchdog/jz4740_wdt.c @@ -26,25 +26,9 @@ #include #include -#include - #define JZ_REG_WDT_TIMER_DATA 0x0 #define JZ_REG_WDT_COUNTER_ENABLE 0x4 #define JZ_REG_WDT_TIMER_COUNTER 0x8 -#define JZ_REG_WDT_TIMER_CONTROL 0xC - -#define JZ_WDT_CLOCK_PCLK 0x1 -#define JZ_WDT_CLOCK_RTC 0x2 -#define JZ_WDT_CLOCK_EXT 0x4 - -#define JZ_WDT_CLOCK_DIV_SHIFT 3 - -#define JZ_WDT_CLOCK_DIV_1 (0 << JZ_WDT_CLOCK_DIV_SHIFT) -#define JZ_WDT_CLOCK_DIV_4 (1 << JZ_WDT_CLOCK_DIV_SHIFT) -#define JZ_WDT_CLOCK_DIV_16 (2 << JZ_WDT_CLOCK_DIV_SHIFT) -#define JZ_WDT_CLOCK_DIV_64 (3 << JZ_WDT_CLOCK_DIV_SHIFT) -#define JZ_WDT_CLOCK_DIV_256 (4 << JZ_WDT_CLOCK_DIV_SHIFT) -#define JZ_WDT_CLOCK_DIV_1024 (5 << JZ_WDT_CLOCK_DIV_SHIFT) #define DEFAULT_HEARTBEAT 5 #define MAX_HEARTBEAT 2048 @@ -65,7 +49,8 @@ MODULE_PARM_DESC(heartbeat, struct jz4740_wdt_drvdata { struct watchdog_device wdt; void __iomem *base; - struct clk *rtc_clk; + struct clk *clk; + unsigned long clk_rate; }; static int jz4740_wdt_ping(struct watchdog_device *wdt_dev) @@ -80,31 +65,12 @@ static int jz4740_wdt_set_timeout(struct watchdog_device *wdt_dev, unsigned int new_timeout) { struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); - unsigned int rtc_clk_rate; - unsigned int timeout_value; - unsigned short clock_div = JZ_WDT_CLOCK_DIV_1; - - rtc_clk_rate = clk_get_rate(drvdata->rtc_clk); - - timeout_value = rtc_clk_rate * new_timeout; - while (timeout_value > 0xffff) { - if (clock_div == JZ_WDT_CLOCK_DIV_1024) { - /* Requested timeout too high; - * use highest possible value. */ - timeout_value = 0xffff; - break; - } - timeout_value >>= 2; - clock_div += (1 << JZ_WDT_CLOCK_DIV_SHIFT); - } + u16 timeout_value = (u16)(drvdata->clk_rate * new_timeout); writeb(0x0, drvdata->base + JZ_REG_WDT_COUNTER_ENABLE); - writew(clock_div, drvdata->base + JZ_REG_WDT_TIMER_CONTROL); writew((u16)timeout_value, drvdata->base + JZ_REG_WDT_TIMER_DATA); writew(0x0, drvdata->base + JZ_REG_WDT_TIMER_COUNTER); - writew(clock_div | JZ_WDT_CLOCK_RTC, - drvdata->base + JZ_REG_WDT_TIMER_CONTROL); writeb(0x1, drvdata->base + JZ_REG_WDT_COUNTER_ENABLE); @@ -114,7 +80,13 @@ static int jz4740_wdt_set_timeout(struct watchdog_device *wdt_dev, static int jz4740_wdt_start(struct watchdog_device *wdt_dev) { - jz4740_timer_enable_watchdog(); + struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); + int ret; + + ret = clk_prepare_enable(drvdata->clk); + if (ret) + return ret; + jz4740_wdt_set_timeout(wdt_dev, wdt_dev->timeout); return 0; @@ -125,7 +97,7 @@ static int jz4740_wdt_stop(struct watchdog_device *wdt_dev) struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); writeb(0x0, drvdata->base + JZ_REG_WDT_COUNTER_ENABLE); - jz4740_timer_disable_watchdog(); + clk_disable_unprepare(drvdata->clk); return 0; } @@ -163,26 +135,42 @@ MODULE_DEVICE_TABLE(of, jz4740_wdt_of_matches); static int jz4740_wdt_probe(struct platform_device *pdev) { + struct device *dev = &pdev->dev; struct jz4740_wdt_drvdata *drvdata; struct watchdog_device *jz4740_wdt; struct resource *res; + long rate; int ret; - drvdata = devm_kzalloc(&pdev->dev, sizeof(struct jz4740_wdt_drvdata), - GFP_KERNEL); + drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL); if (!drvdata) return -ENOMEM; - if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT) - heartbeat = DEFAULT_HEARTBEAT; + drvdata->clk = devm_clk_get(&pdev->dev, "wdt"); + if (IS_ERR(drvdata->clk)) { + dev_err(&pdev->dev, "cannot find WDT clock\n"); + return PTR_ERR(drvdata->clk); + } + + /* Set smallest clock possible */ + rate = clk_round_rate(drvdata->clk, 1); + if (rate < 0) + return rate; + ret = clk_set_rate(drvdata->clk, rate); + if (ret) + return ret; + + drvdata->clk_rate = rate; jz4740_wdt = &drvdata->wdt; jz4740_wdt->info = &jz4740_wdt_info; jz4740_wdt->ops = &jz4740_wdt_ops; - jz4740_wdt->timeout = heartbeat; jz4740_wdt->min_timeout = 1; - jz4740_wdt->max_timeout = MAX_HEARTBEAT; - jz4740_wdt->parent = &pdev->dev; + jz4740_wdt->max_timeout = 0xffff / rate; + jz4740_wdt->timeout = clamp(heartbeat, + jz4740_wdt->min_timeout, + jz4740_wdt->max_timeout); + jz4740_wdt->parent = dev; watchdog_set_nowayout(jz4740_wdt, nowayout); watchdog_set_drvdata(jz4740_wdt, drvdata); @@ -191,12 +179,6 @@ static int jz4740_wdt_probe(struct platform_device *pdev) if (IS_ERR(drvdata->base)) return PTR_ERR(drvdata->base); - drvdata->rtc_clk = devm_clk_get(&pdev->dev, "rtc"); - if (IS_ERR(drvdata->rtc_clk)) { - dev_err(&pdev->dev, "cannot find RTC clock\n"); - return PTR_ERR(drvdata->rtc_clk); - } - ret = devm_watchdog_register_device(&pdev->dev, &drvdata->wdt); if (ret < 0) return ret;