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 X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 91C73C4321E for ; Sat, 8 Sep 2018 15:10:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3482F206BB for ; Sat, 8 Sep 2018 15:10:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3482F206BB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727369AbeIHT4Q (ORCPT ); Sat, 8 Sep 2018 15:56:16 -0400 Received: from mail.bootlin.com ([62.4.15.54]:34864 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726703AbeIHT4P (ORCPT ); Sat, 8 Sep 2018 15:56:15 -0400 Received: by mail.bootlin.com (Postfix, from userid 110) id ED26F207AD; Sat, 8 Sep 2018 17:10:07 +0200 (CEST) Received: from localhost (unknown [88.191.26.124]) by mail.bootlin.com (Postfix) with ESMTPSA id B5A00204AE; Sat, 8 Sep 2018 17:09:57 +0200 (CEST) Date: Sat, 8 Sep 2018 17:09:57 +0200 From: Alexandre Belloni To: Jeremy Gebben Cc: Alessandro Zummo , linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] rtc: abx80x: add basic watchdog support Message-ID: <20180908150957.GD2598@piout.net> References: <20180907151744.32634-1-jgebben@sweptlaser.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180907151744.32634-1-jgebben@sweptlaser.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Please Cc the watchdog maintainers. Else, I have very few comments. On 07/09/2018 09:17:43-0600, Jeremy Gebben wrote: > The abx804 and abx805 chips have support for a simple watchdog > function that can trigger an external reset. > > Signed-off-by: Jeremy Gebben > --- > drivers/rtc/Kconfig | 11 +++ > drivers/rtc/rtc-abx80x.c | 160 ++++++++++++++++++++++++++++++++++++--- > 2 files changed, 159 insertions(+), 12 deletions(-) > > diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig > index 7d7be60a2413..4771e3a89721 100644 > --- a/drivers/rtc/Kconfig > +++ b/drivers/rtc/Kconfig > @@ -195,6 +195,17 @@ config RTC_DRV_ABX80X > This driver can also be built as a module. If so, the module > will be called rtc-abx80x. > > +config RTC_DRV_ABX80X_WDT > + bool "Abracon ABx80x Watchdog" > + default y > + depends on RTC_DRV_ABX80X > + help > + If you say yes here you get watchdog support for Abracon ABX804 and ABX805 > + clock chips. This watchdog supports timeouts up to 31 seconds with 1 second > + granularity. > + > + This watchdog device is part of the rtc-abx80x module. > + I'm not sure it is worth having a separate config option for that. You may as well just always include the watchdog support code. However, doesn't it need to depend on CONFIG_WATCHDOG? > config RTC_DRV_AC100 > tristate "X-Powers AC100" > depends on MFD_AC100 > diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c > index 2cefa67a1132..fa558939e944 100644 > --- a/drivers/rtc/rtc-abx80x.c > +++ b/drivers/rtc/rtc-abx80x.c > @@ -17,6 +17,7 @@ > #include > #include > #include > +#include > > #define ABX8XX_REG_HTH 0x00 > #define ABX8XX_REG_SC 0x01 > @@ -37,6 +38,7 @@ > > #define ABX8XX_REG_STATUS 0x0f > #define ABX8XX_STATUS_AF BIT(2) > +#define ABX8XX_STATUS_WDT BIT(6) > > #define ABX8XX_REG_CTRL1 0x10 > #define ABX8XX_CTRL_WRITE BIT(0) > @@ -61,6 +63,14 @@ > #define ABX8XX_OSS_OF BIT(1) > #define ABX8XX_OSS_OMODE BIT(4) > > +#define ABX8XX_REG_WDT 0x1b > +#define ABX8XX_WDT_WDS BIT(7) > +#define ABX8XX_WDT_BMB_MASK 0x7c > +#define ABX8XX_WDT_BMB_SHIFT 2 > +#define ABX8XX_WDT_MAX_TIME (ABX8XX_WDT_BMB_MASK >> ABX8XX_WDT_BMB_SHIFT) > +#define ABX8XX_WDT_WRB_MASK 0x03 > +#define ABX8XX_WDT_WRB_1HZ 0x02 > + > #define ABX8XX_REG_CFG_KEY 0x1f > #define ABX8XX_CFG_KEY_OSC 0xa1 > #define ABX8XX_CFG_KEY_MISC 0x9d > @@ -80,20 +90,27 @@ enum abx80x_chip {AB0801, AB0803, AB0804, AB0805, > struct abx80x_cap { > u16 pn; > bool has_tc; > + bool has_wdog; > }; > > static struct abx80x_cap abx80x_caps[] = { > [AB0801] = {.pn = 0x0801}, > [AB0803] = {.pn = 0x0803}, > - [AB0804] = {.pn = 0x0804, .has_tc = true}, > - [AB0805] = {.pn = 0x0805, .has_tc = true}, > + [AB0804] = {.pn = 0x0804, .has_tc = true, .has_wdog = true}, > + [AB0805] = {.pn = 0x0805, .has_tc = true, .has_wdog = true}, > [AB1801] = {.pn = 0x1801}, > [AB1803] = {.pn = 0x1803}, > - [AB1804] = {.pn = 0x1804, .has_tc = true}, > - [AB1805] = {.pn = 0x1805, .has_tc = true}, > + [AB1804] = {.pn = 0x1804, .has_tc = true, .has_wdog = true}, > + [AB1805] = {.pn = 0x1805, .has_tc = true, .has_wdog = true}, > [ABX80X] = {.pn = 0} > }; > > +struct abx80x_priv { > + struct rtc_device *rtc; > + struct i2c_client *client; > + struct watchdog_device wdog; > +}; > + To make the watchdog part easier to review, you could separate the introduction of abx80x_priv in a preliminary patch and then introduce the watchdog code. > static int abx80x_is_rc_mode(struct i2c_client *client) > { > int flags = 0; > @@ -218,7 +235,8 @@ static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm) > static irqreturn_t abx80x_handle_irq(int irq, void *dev_id) > { > struct i2c_client *client = dev_id; > - struct rtc_device *rtc = i2c_get_clientdata(client); > + struct abx80x_priv *priv = i2c_get_clientdata(client); > + struct rtc_device *rtc = priv->rtc; > int status; > > status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS); > @@ -228,6 +246,13 @@ static irqreturn_t abx80x_handle_irq(int irq, void *dev_id) > if (status & ABX8XX_STATUS_AF) > rtc_update_irq(rtc, 1, RTC_AF | RTC_IRQF); > > + /* > + * It is unclear if we'll get an interrupt before the external > + * reset kicks in. > + */ > + if (status & ABX8XX_STATUS_WDT) > + dev_err(&client->dev, "watchdog timeout interrupt!\n"); > + dev_alert maybe? > i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0); > > return IRQ_HANDLED; > @@ -529,11 +554,110 @@ static void rtc_calib_remove_sysfs_group(void *_dev) > sysfs_remove_group(&dev->kobj, &rtc_calib_attr_group); > } > > +#ifdef CONFIG_RTC_DRV_ABX80X_WDT > + > +static inline u8 timeout_bits(unsigned int timeout) > +{ > + return ((timeout << ABX8XX_WDT_BMB_SHIFT) & ABX8XX_WDT_BMB_MASK) | > + ABX8XX_WDT_WRB_1HZ; > +} > + > +static int __abx80x_wdog_set_timeout(struct watchdog_device *wdog, > + unsigned int timeout) > +{ > + struct abx80x_priv *priv = watchdog_get_drvdata(wdog); > + u8 val = ABX8XX_WDT_WDS | timeout_bits(timeout); > + > + /* > + * Writing any timeout to the WDT register resets the watchdog timer. > + * Writing 0 disables it. > + */ > + return i2c_smbus_write_byte_data(priv->client, ABX8XX_REG_WDT, val); > +} > + > +static int abx80x_wdog_set_timeout(struct watchdog_device *wdog, > + unsigned int new_timeout) > +{ > + int err = __abx80x_wdog_set_timeout(wdog, new_timeout); > + > + if (err) > + return err; > + > + wdog->timeout = new_timeout; > + return 0; > +} > + > +static int abx80x_wdog_ping(struct watchdog_device *wdog) > +{ > + return __abx80x_wdog_set_timeout(wdog, wdog->timeout); > +} > + > +static int abx80x_wdog_start(struct watchdog_device *wdog) > +{ > + int err = __abx80x_wdog_set_timeout(wdog, wdog->timeout); > + > + if (err) > + return err; > + > + set_bit(WDOG_HW_RUNNING, &wdog->status); > + return 0; > +} > + > +static int abx80x_wdog_stop(struct watchdog_device *wdog) > +{ > + int err = __abx80x_wdog_set_timeout(wdog, 0); > + > + if (err) > + return err; > + > + clear_bit(WDOG_HW_RUNNING, &wdog->status); > + return 0; > +} > + > +static const struct watchdog_info abx80x_wdog_info = { > + .identity = "abx80x watchdog", > + .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, > +}; > + > +static const struct watchdog_ops abx80x_wdog_ops = { > + .owner = THIS_MODULE, > + .start = abx80x_wdog_start, > + .stop = abx80x_wdog_stop, > + .ping = abx80x_wdog_ping, > + .set_timeout = abx80x_wdog_set_timeout, > +}; > + > +static int abx80x_setup_watchdog(struct abx80x_priv *priv) > +{ > + int err; > + > + priv->wdog.ops = &abx80x_wdog_ops; > + priv->wdog.info = &abx80x_wdog_info; > + priv->wdog.min_timeout = 1; > + priv->wdog.max_timeout = ABX8XX_WDT_MAX_TIME; > + > + err = devm_watchdog_register_device(&priv->client->dev, > + &priv->wdog); > + if (err) > + return err; > + > + watchdog_set_drvdata(&priv->wdog, priv); > + watchdog_init_timeout(&priv->wdog, ABX8XX_WDT_MAX_TIME, > + &priv->client->dev); > + return 0; > +} > +#else > +static int abx80x_setup_watchdog(struct abx80x_priv *priv) > +{ > + return 0; > +} > +#endif > + > static int abx80x_probe(struct i2c_client *client, > const struct i2c_device_id *id) > { > struct device_node *np = client->dev.of_node; > - struct rtc_device *rtc; > + struct abx80x_priv *priv; > int i, data, err, trickle_cfg = -EINVAL; > char buf[7]; > unsigned int part = id->driver_data; > @@ -610,13 +734,25 @@ static int abx80x_probe(struct i2c_client *client, > if (err) > return err; > > - rtc = devm_rtc_allocate_device(&client->dev); > - if (IS_ERR(rtc)) > - return PTR_ERR(rtc); > + priv = devm_kzalloc(&client->dev, sizeof(struct abx80x_priv), > + GFP_KERNEL); > + if (priv == NULL) > + return -ENOMEM; > + > + priv->rtc = devm_rtc_allocate_device(&client->dev); > + if (IS_ERR(priv->rtc)) > + return PTR_ERR(priv->rtc); > > - rtc->ops = &abx80x_rtc_ops; > + priv->rtc->ops = &abx80x_rtc_ops; > + priv->client = client; > > - i2c_set_clientdata(client, rtc); > + i2c_set_clientdata(client, priv); > + > + if (abx80x_caps[part].has_wdog) { > + err = abx80x_setup_watchdog(priv); > + if (err) > + return err; > + } > > if (client->irq > 0) { > dev_info(&client->dev, "IRQ %d supplied\n", client->irq); > @@ -649,7 +785,7 @@ static int abx80x_probe(struct i2c_client *client, > return err; > } > > - err = rtc_register_device(rtc); > + err = rtc_register_device(priv->rtc); > > return err; > } > -- > 2.17.1 > -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com