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=-7.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNWANTED_LANGUAGE_BODY,USER_AGENT_GIT autolearn=unavailable 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 0604FC433E1 for ; Tue, 7 Jul 2020 21:10:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D3850206F6 for ; Tue, 7 Jul 2020 21:10:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=alliedtelesis.co.nz header.i=@alliedtelesis.co.nz header.b="VoeWPTYk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728299AbgGGVKr (ORCPT ); Tue, 7 Jul 2020 17:10:47 -0400 Received: from gate2.alliedtelesis.co.nz ([202.36.163.20]:55318 "EHLO gate2.alliedtelesis.co.nz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728385AbgGGVKr (ORCPT ); Tue, 7 Jul 2020 17:10:47 -0400 Received: from mmarshal3.atlnz.lc (mmarshal3.atlnz.lc [10.32.18.43]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by gate2.alliedtelesis.co.nz (Postfix) with ESMTPS id A32958011F; Wed, 8 Jul 2020 09:10:40 +1200 (NZST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alliedtelesis.co.nz; s=mail181024; t=1594156240; bh=LIZaTJsVpo0fc9R6NrZDyGHqCTXkr77kbJtYcUTyeeY=; h=From:To:Cc:Subject:Date; b=VoeWPTYkyjGp1TCIpSRUpTYa41WqdVf2g2Yif/cCo1GmlQOFmMjCI+DSjGUY6oqvr aZGPedZbELz40rAmV06xDppbX7DBnak/JgCqzyoL1jaczE2xqLJBld1o2yxUUh+5ho gglKWRFKGkGA6gVWVhzjLSRiQ8ts2aV4YSo6tlXbu9PIw51H2GlNGSUl39vjalOMA7 cmi/HeOD3RX9owELCSXuACs3jXkdSWUJFf3+pNJswwUD9SHGPjTMKnsenCSgMWN/U3 HIa93UUSEg1NT8WnIniRloQ7ECy9Lzo4r9/zOnBlYMQvbgr5tdWzA2Lshr1Kkzfzl/ cEF2HdcZiCkdA== Received: from smtp (Not Verified[10.32.16.33]) by mmarshal3.atlnz.lc with Trustwave SEG (v7,5,8,10121) id ; Wed, 08 Jul 2020 09:10:40 +1200 Received: from markto-dl.ws.atlnz.lc (markto-dl.ws.atlnz.lc [10.33.23.25]) by smtp (Postfix) with ESMTP id 2720D13EDDC; Wed, 8 Jul 2020 09:10:39 +1200 (NZST) Received: by markto-dl.ws.atlnz.lc (Postfix, from userid 1155) id 3C327341145; Wed, 8 Jul 2020 09:10:40 +1200 (NZST) From: Mark Tomlinson To: gregory.clement@bootlin.com Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, Mark Tomlinson Subject: [PATCH] i2c: mv64xxx: Add bus error recovery Date: Wed, 8 Jul 2020 09:10:36 +1200 Message-Id: <20200707211036.12896-1-mark.tomlinson@alliedtelesis.co.nz> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable x-atlnz-ls: pat Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org This adds i2c bus recovery to the mv64xxx driver. Implement bus recovery to recover from SCL/SDA stuck low. This uses the generic recovery function, setting the clock/data lines as GPIO pins, and sending 9 clocks to try and recover the bus. Signed-off-by: Mark Tomlinson --- drivers/i2c/busses/i2c-mv64xxx.c | 77 +++++++++++++++++++++++++++++++- 1 file changed, 76 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv= 64xxx.c index 829b8c98ae51..e58853ba3ef0 100644 --- a/drivers/i2c/busses/i2c-mv64xxx.c +++ b/drivers/i2c/busses/i2c-mv64xxx.c @@ -21,6 +21,7 @@ #include #include #include +#include #include #include #include @@ -147,6 +148,10 @@ struct mv64xxx_i2c_data { bool irq_clear_inverted; /* Clk div is 2 to the power n, not 2 to the power n + 1 */ bool clk_n_base_0; + struct pinctrl *pinctrl; + struct i2c_bus_recovery_info rinfo; + struct pinctrl_state *pin_default_state; + struct pinctrl_state *pin_gpio_state; }; =20 static struct mv64xxx_i2c_regs mv64xxx_i2c_regs_mv64xxx =3D { @@ -325,7 +330,8 @@ mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u3= 2 status) drv_data->msg->flags); drv_data->action =3D MV64XXX_I2C_ACTION_SEND_STOP; mv64xxx_i2c_hw_init(drv_data); - drv_data->rc =3D -EIO; + i2c_recover_bus(&drv_data->adapter); + drv_data->rc =3D -EAGAIN; } } =20 @@ -563,6 +569,7 @@ mv64xxx_i2c_wait_for_completion(struct mv64xxx_i2c_da= ta *drv_data) "time_left: %d\n", drv_data->block, (int)time_left); mv64xxx_i2c_hw_init(drv_data); + i2c_recover_bus(&drv_data->adapter); } } else spin_unlock_irqrestore(&drv_data->lock, flags); @@ -872,6 +879,69 @@ mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data, } #endif /* CONFIG_OF */ =20 +/* + * Switch to bit bang mode to prepare for i2c generic recovery. + */ +static void mv64xxx_i2c_prepare_recovery(struct i2c_adapter *adap) +{ + struct mv64xxx_i2c_data *drv_data =3D i2c_get_adapdata(adap); + + pinctrl_select_state(drv_data->pinctrl, drv_data->pin_gpio_state); +} + +/* + * Return to normal i2c operation following recovery. + */ +static void mv64xxx_i2c_unprepare_recovery(struct i2c_adapter *adap) +{ + struct mv64xxx_i2c_data *drv_data =3D i2c_get_adapdata(adap); + + pinctrl_select_state(drv_data->pinctrl, drv_data->pin_default_state); +} + +static int mv64xxx_i2c_init_recovery_info(struct mv64xxx_i2c_data *drv_d= ata, + struct platform_device *pd) +{ + struct i2c_bus_recovery_info *rinfo =3D &drv_data->rinfo; + struct device *dev =3D &pd->dev; + + drv_data->pinctrl =3D devm_pinctrl_get(dev); + if (!drv_data->pinctrl || IS_ERR(drv_data->pinctrl)) { + dev_err(dev, "can't get pinctrl, bus recovery not supported\n"); + return PTR_ERR(drv_data->pinctrl); + } + + drv_data->pin_default_state =3D pinctrl_lookup_state(drv_data->pinctrl, + PINCTRL_STATE_DEFAULT); + drv_data->pin_gpio_state =3D pinctrl_lookup_state(drv_data->pinctrl, + "gpio"); + rinfo->scl_gpiod =3D devm_gpiod_get(dev, "scl", + GPIOD_OUT_HIGH_OPEN_DRAIN); + rinfo->sda_gpiod =3D devm_gpiod_get(dev, "sda", GPIOD_IN); + if (PTR_ERR(rinfo->scl_gpiod) =3D=3D -EPROBE_DEFER || + PTR_ERR(rinfo->sda_gpiod) =3D=3D -EPROBE_DEFER) + return -EPROBE_DEFER; + + if (IS_ERR(rinfo->sda_gpiod) || + IS_ERR(rinfo->scl_gpiod) || + IS_ERR(drv_data->pin_default_state) || + IS_ERR(drv_data->pin_gpio_state)) { + dev_dbg(dev, "recovery information incomplete\n"); + return 0; + } + + dev_dbg(dev, "using scl-gpio %d and sda-gpio %d for recovery\n", + rinfo->scl_gpiod ? desc_to_gpio(rinfo->scl_gpiod) : -1, + rinfo->sda_gpiod ? desc_to_gpio(rinfo->sda_gpiod) : -1); + + rinfo->prepare_recovery =3D mv64xxx_i2c_prepare_recovery; + rinfo->unprepare_recovery =3D mv64xxx_i2c_unprepare_recovery; + rinfo->recover_bus =3D i2c_generic_scl_recovery; + drv_data->adapter.bus_recovery_info =3D rinfo; + + return 0; +} + static int mv64xxx_i2c_probe(struct platform_device *pd) { @@ -939,6 +1009,10 @@ mv64xxx_i2c_probe(struct platform_device *pd) =20 mv64xxx_i2c_hw_init(drv_data); =20 + rc =3D mv64xxx_i2c_init_recovery_info(drv_data, pd); + if (rc =3D=3D -EPROBE_DEFER) + goto exit_reset; + rc =3D request_irq(drv_data->irq, mv64xxx_i2c_intr, 0, MV64XXX_I2C_CTLR_NAME, drv_data); if (rc) { @@ -951,6 +1025,7 @@ mv64xxx_i2c_probe(struct platform_device *pd) "mv64xxx: Can't add i2c adapter, rc: %d\n", -rc); goto exit_free_irq; } + i2c_recover_bus(&drv_data->adapter); =20 return 0; =20 --=20 2.27.0