From patchwork Thu Dec 5 14:03:04 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamel BOUHARA X-Patchwork-Id: 11274823 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3D0F3930 for ; Thu, 5 Dec 2019 14:03:34 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1AD0F21823 for ; Thu, 5 Dec 2019 14:03:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="tSfhKklQ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1AD0F21823 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-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=onoM4i5vxHAF7nu1jG25K95WxBvKmWZV2SnFW40SvN8=; b=tSfhKklQdTlta7 NDoRS98R1t5M7qBC+l6DBd3srgMC/dHkaTjFE2O0EpRvEBT7PiMkHhlxa2ebRO17rZtfubRlKePVX N3wlZ/yCIZg1v8Vxos+k7znC/dhOjwjrhg7LgDgqiUpIr7ZqleCIHyc1oL6cj17+IOdKLCmDf1uM1 ebuSpgsv4VZwrYiZSBvXPINeR2DKJvLMyHbmJBvpYohaDjVoZqC3VZQejmgJbAArDu5FDcWuIRQjX fqyjtnJaQ9cPiuxnazUyB5QW1xRmMiIgXsSwhLkvxL+cC4FczweS2lWY9BZ3MmdJGVl9j807LVWVi di93m2RgdGAJOo0En/DA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1icrj8-0002aA-7T; Thu, 05 Dec 2019 14:03:30 +0000 Received: from relay4-d.mail.gandi.net ([217.70.183.196]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1icriz-0002Sa-DL for linux-arm-kernel@lists.infradead.org; Thu, 05 Dec 2019 14:03:23 +0000 X-Originating-IP: 90.65.102.129 Received: from localhost (lfbn-1-1480-129.w90-65.abo.wanadoo.fr [90.65.102.129]) (Authenticated sender: kamel.bouhara@bootlin.com) by relay4-d.mail.gandi.net (Postfix) with ESMTPSA id D8EC9E0019; Thu, 5 Dec 2019 14:03:15 +0000 (UTC) From: Kamel Bouhara To: Codrin.Ciubotariu@microchip.com Subject: [PATCH 2/3] i2c: at91: implement i2c bus recovery Date: Thu, 5 Dec 2019 15:03:04 +0100 Message-Id: <20191205140305.1144788-3-kamel.bouhara@bootlin.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191205140305.1144788-1-kamel.bouhara@bootlin.com> References: <20191205140305.1144788-1-kamel.bouhara@bootlin.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191205_060321_723612_2247363F X-CRM114-Status: GOOD ( 11.03 ) X-Spam-Score: -0.7 (/) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (-0.7 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at https://www.dnswl.org/, low trust [217.70.183.196 listed in list.dnswl.org] 0.0 RCVD_IN_MSPIKE_H3 RBL: Good reputation (+3) [217.70.183.196 listed in wl.mailspike.net] 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 SPF_PASS SPF: sender matches SPF record 0.0 RCVD_IN_MSPIKE_WL Mailspike good senders X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kamel Bouhara , Alexandre Belloni , Ludovic Desroches , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org 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. Signed-off-by: Kamel Bouhara --- drivers/i2c/busses/i2c-at91-master.c | 64 ++++++++++++++++++++++++++++ drivers/i2c/busses/i2c-at91.h | 8 ++++ 2 files changed, 72 insertions(+) diff --git a/drivers/i2c/busses/i2c-at91-master.c b/drivers/i2c/busses/i2c-at91-master.c index a3fcc35ffd3b..e279129e6a76 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 @@ -554,6 +556,7 @@ static int at91_do_twi_transfer(struct at91_twi_dev *dev) if (time_left == 0) { dev->transfer_status |= at91_twi_read(dev, AT91_TWI_SR); dev_err(dev->dev, "controller timed out\n"); + i2c_recover_bus(&dev->adapter); at91_init_twi_bus(dev); ret = -ETIMEDOUT; goto error; @@ -768,6 +771,63 @@ 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 +855,10 @@ 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,