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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 471E8C47404 for ; Wed, 9 Oct 2019 13:54:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2181A2067B for ; Wed, 9 Oct 2019 13:54:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731145AbfJINyy (ORCPT ); Wed, 9 Oct 2019 09:54:54 -0400 Received: from esa1.microchip.iphmx.com ([68.232.147.91]:46987 "EHLO esa1.microchip.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729865AbfJINyx (ORCPT ); Wed, 9 Oct 2019 09:54:53 -0400 Received-SPF: Pass (esa1.microchip.iphmx.com: domain of Ludovic.Desroches@microchip.com designates 198.175.253.82 as permitted sender) identity=mailfrom; client-ip=198.175.253.82; receiver=esa1.microchip.iphmx.com; envelope-from="Ludovic.Desroches@microchip.com"; x-sender="Ludovic.Desroches@microchip.com"; x-conformance=spf_only; x-record-type="v=spf1"; x-record-text="v=spf1 mx a:ushub1.microchip.com a:smtpout.microchip.com a:mx1.microchip.iphmx.com a:mx2.microchip.iphmx.com include:servers.mcsv.net include:mktomail.com include:spf.protection.outlook.com ~all" Received-SPF: None (esa1.microchip.iphmx.com: no sender authenticity information available from domain of postmaster@email.microchip.com) identity=helo; client-ip=198.175.253.82; receiver=esa1.microchip.iphmx.com; envelope-from="Ludovic.Desroches@microchip.com"; x-sender="postmaster@email.microchip.com"; x-conformance=spf_only Authentication-Results: esa1.microchip.iphmx.com; dkim=none (message not signed) header.i=none; spf=Pass smtp.mailfrom=Ludovic.Desroches@microchip.com; spf=None smtp.helo=postmaster@email.microchip.com; dmarc=pass (p=none dis=none) d=microchip.com IronPort-SDR: 2Xl7UaHbX/XBwKudh3GNDw3t7vZb5xSHn+qO3PjAJXY1cjVXcwlc1uVVmakt6K5huOLo6QWmcf blVmeni2K07fxDUzTNq62aDW2f/CZkCmlQ6on9DkCw2+c7McLMRqJFMGhHbJSNc4eQWifsD5+O guWOQJUPi91uhJyZsHbxwYQOHoD2lUPQY3wmZ0v25wjGgpsJijEd27qA+Ekp2qlS+9cxrrq+if bK1sBYo8EpwivEeMKpf0Dzff1qltqg7iRQ8Ij94MhY8BqkSVCQrWUdVSx1gUK2Ba8SM3qa2yp2 8c4= X-IronPort-AV: E=Sophos;i="5.67,276,1566889200"; d="scan'208";a="53595269" Received: from smtpout.microchip.com (HELO email.microchip.com) ([198.175.253.82]) by esa1.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 09 Oct 2019 06:54:52 -0700 Received: from chn-vm-ex01.mchp-main.com (10.10.85.143) by chn-vm-ex04.mchp-main.com (10.10.85.152) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Wed, 9 Oct 2019 06:54:52 -0700 Received: from localhost (10.10.85.251) by chn-vm-ex01.mchp-main.com (10.10.85.143) with Microsoft SMTP Server id 15.1.1713.5 via Frontend Transport; Wed, 9 Oct 2019 06:54:51 -0700 Date: Wed, 9 Oct 2019 15:55:00 +0200 From: Ludovic Desroches To: Kamel Bouhara CC: Wolfram Sang , , , Nicolas Ferre , Alexandre Belloni , , , "Thomas Petazzoni" Subject: Re: [PATCH 2/4] i2c: at91: implement i2c bus recovery Message-ID: <20191009135500.ufkxcemccwfcfys7@M43218.corp.atmel.com> Mail-Followup-To: Kamel Bouhara , Wolfram Sang , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, Nicolas Ferre , Alexandre Belloni , linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, Thomas Petazzoni References: <20191002144658.7718-1-kamel.bouhara@bootlin.com> <20191002144658.7718-3-kamel.bouhara@bootlin.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20191002144658.7718-3-kamel.bouhara@bootlin.com> User-Agent: NeoMutt/20180716 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 02, 2019 at 04:46:56PM +0200, Kamel Bouhara wrote: > External E-Mail > > > Implement i2c bus recovery when slaves devices might hold SDA low. > In this case re-assign SCL/SDA to gpios and issue 9 dummy clock pulses > until the slave release SDA. > Hi Kamel, Thanks for adding this new feature. As I see patches only for sama5d3 and sama5d4, I assume it has not been tested with a sama5d2, isn't it? I doubt it works with a sama5d2 because of the pinctrl. I also wonder if it can work if we add .strict = true to pinmux_ops which is something plan for the future... Are you able to test these points? It would be nice to be aware of possible side effects. Regards Ludovic > Signed-off-by: Kamel Bouhara > --- > drivers/i2c/busses/i2c-at91-master.c | 63 ++++++++++++++++++++++++++++ > drivers/i2c/busses/i2c-at91.h | 8 ++++ > 2 files changed, 71 insertions(+) > > diff --git a/drivers/i2c/busses/i2c-at91-master.c b/drivers/i2c/busses/i2c-at91-master.c > index a3fcc35ffd3b..df5bb93f952d 100644 > --- a/drivers/i2c/busses/i2c-at91-master.c > +++ b/drivers/i2c/busses/i2c-at91-master.c > @@ -18,11 +18,13 @@ > #include > #include > #include > +#include > #include > #include > #include > #include > #include > +#include > #include > #include > #include > @@ -768,6 +770,63 @@ static int at91_twi_configure_dma(struct at91_twi_dev *dev, u32 phy_addr) > return ret; > } > > +static void at91_prepare_twi_recovery(struct i2c_adapter *adap) > +{ > + struct at91_twi_dev *dev = i2c_get_adapdata(adap); > + > + pinctrl_select_state(dev->pinctrl, dev->pinctrl_pins_gpio); > +} > + > +static void at91_unprepare_twi_recovery(struct i2c_adapter *adap) > +{ > + struct at91_twi_dev *dev = i2c_get_adapdata(adap); > + > + pinctrl_select_state(dev->pinctrl, dev->pinctrl_pins_default); > +} > + > +static int at91_init_twi_recovery_info(struct platform_device *pdev, > + struct at91_twi_dev *dev) > +{ > + struct i2c_bus_recovery_info *rinfo = &dev->rinfo; > + > + dev->pinctrl = devm_pinctrl_get(&pdev->dev); > + if (!dev->pinctrl || IS_ERR(dev->pinctrl)) { > + dev_info(dev->dev, "can't get pinctrl, bus recovery not supported\n"); > + return PTR_ERR(dev->pinctrl); > + } > + > + dev->pinctrl_pins_default = pinctrl_lookup_state(dev->pinctrl, > + PINCTRL_STATE_DEFAULT); > + dev->pinctrl_pins_gpio = pinctrl_lookup_state(dev->pinctrl, > + "gpio"); > + rinfo->sda_gpiod = devm_gpiod_get(&pdev->dev, "sda", GPIOD_IN); > + if (PTR_ERR(rinfo->sda_gpiod) == -EPROBE_DEFER) > + return -EPROBE_DEFER; > + > + rinfo->scl_gpiod = devm_gpiod_get(&pdev->dev, "scl", > + GPIOD_OUT_HIGH_OPEN_DRAIN); > + if (PTR_ERR(rinfo->scl_gpiod) == -EPROBE_DEFER) > + return -EPROBE_DEFER; > + > + if (IS_ERR(rinfo->sda_gpiod) || > + IS_ERR(rinfo->scl_gpiod) || > + IS_ERR(dev->pinctrl_pins_default) || > + IS_ERR(dev->pinctrl_pins_gpio)) { > + dev_info(&pdev->dev, "recovery information incomplete\n"); > + return -EINVAL; > + } > + > + dev_info(&pdev->dev, "using scl%s for recovery\n", > + rinfo->sda_gpiod ? ",sda" : ""); > + > + rinfo->prepare_recovery = at91_prepare_twi_recovery; > + rinfo->unprepare_recovery = at91_unprepare_twi_recovery; > + rinfo->recover_bus = i2c_generic_scl_recovery; > + dev->adapter.bus_recovery_info = rinfo; > + > + return 0; > +} > + > int at91_twi_probe_master(struct platform_device *pdev, > u32 phy_addr, struct at91_twi_dev *dev) > { > @@ -795,6 +854,10 @@ int at91_twi_probe_master(struct platform_device *pdev, > > at91_calc_twi_clock(dev); > > + rc = at91_init_twi_recovery_info(pdev, dev); > + if (rc == -EPROBE_DEFER) > + return rc; > + > dev->adapter.algo = &at91_twi_algorithm; > dev->adapter.quirks = &at91_twi_quirks; > > diff --git a/drivers/i2c/busses/i2c-at91.h b/drivers/i2c/busses/i2c-at91.h > index 499b506f6128..b89dab55e776 100644 > --- a/drivers/i2c/busses/i2c-at91.h > +++ b/drivers/i2c/busses/i2c-at91.h > @@ -141,6 +141,10 @@ struct at91_twi_dev { > u32 fifo_size; > struct at91_twi_dma dma; > bool slave_detected; > + struct i2c_bus_recovery_info rinfo; > + struct pinctrl *pinctrl; > + struct pinctrl_state *pinctrl_pins_default; > + struct pinctrl_state *pinctrl_pins_gpio; > #ifdef CONFIG_I2C_AT91_SLAVE_EXPERIMENTAL > unsigned smr; > struct i2c_client *slave; > @@ -158,6 +162,10 @@ void at91_init_twi_bus_master(struct at91_twi_dev *dev); > int at91_twi_probe_master(struct platform_device *pdev, u32 phy_addr, > struct at91_twi_dev *dev); > > +void at91_twi_prepare_recovery(struct i2c_adapter *adap); > +void at91_twi_unprepare_recovery(struct i2c_adapter *adap); > +void at91_twi_init_recovery_info(struct at91_twi_dev *dev); > + > #ifdef CONFIG_I2C_AT91_SLAVE_EXPERIMENTAL > void at91_init_twi_bus_slave(struct at91_twi_dev *dev); > int at91_twi_probe_slave(struct platform_device *pdev, u32 phy_addr, > -- > 2.23.0 > >