From patchwork Thu Nov 30 16:25:22 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Elad Nachman X-Patchwork-Id: 1870300 X-Patchwork-Delegate: andi.shyti@kernel.org Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=marvell.com header.i=@marvell.com header.a=rsa-sha256 header.s=pfpt0220 header.b=KRSn0HGq; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=147.75.80.249; helo=am.mirrors.kernel.org; envelope-from=linux-i2c+bounces-568-incoming=patchwork.ozlabs.org@vger.kernel.org; receiver=patchwork.ozlabs.org) Received: from am.mirrors.kernel.org (am.mirrors.kernel.org [147.75.80.249]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (secp384r1)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4Sh1lD12Syz23mq for ; Fri, 1 Dec 2023 03:25:44 +1100 (AEDT) Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by am.mirrors.kernel.org (Postfix) with ESMTPS id 130CC1F20F26 for ; Thu, 30 Nov 2023 16:25:41 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id D2EA654F98; Thu, 30 Nov 2023 16:25:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=marvell.com header.i=@marvell.com header.b="KRSn0HGq" X-Original-To: linux-i2c@vger.kernel.org Received: from mx0b-0016f401.pphosted.com (mx0b-0016f401.pphosted.com [67.231.156.173]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D34C210DB; Thu, 30 Nov 2023 08:25:34 -0800 (PST) Received: from pps.filterd (m0045851.ppops.net [127.0.0.1]) by mx0b-0016f401.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 3AUGJouc029983; Thu, 30 Nov 2023 08:25:29 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=marvell.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding : content-type; s=pfpt0220; bh=Y9ZGGutZF1LKL6hXrt3Hb8FV4Vcd4Mv1oLkRcfF6oYo=; b=KRSn0HGqSXrleSEQAM5DK7PSmvnijYyzlH0L5T48Wso3p9RnY83ujVbdGpkNOAEJ4oEr FfHQhWxe78yB28P+n77LMF5x+8elH7LnuqVZkbGfWEbnf66Bpkqdcei9j/4muRa5LiO8 YortAjMm1arn0N+beNvLmShGSL1gg8O9fvmJtXZ/JHKo6fmn1iV79QZw8iAKETfN5nPZ o/qXeIAaPDWvU78G/09UkX0nRWnyloy8vcu6KRRP/bmYreF3uAUS2LEalHJnRDUWS92T OJnHkVw6syt4CCvIDEwIrSVSVbFQdH/td+yj7kMi4EjPCml1Jqtu/EJiAVCWB1DX5oyk PQ== Received: from dc5-exch02.marvell.com ([199.233.59.182]) by mx0b-0016f401.pphosted.com (PPS) with ESMTPS id 3updt6c56f-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT); Thu, 30 Nov 2023 08:25:29 -0800 Received: from DC5-EXCH01.marvell.com (10.69.176.38) by DC5-EXCH02.marvell.com (10.69.176.39) with Microsoft SMTP Server (TLS) id 15.0.1497.48; Thu, 30 Nov 2023 08:25:27 -0800 Received: from maili.marvell.com (10.69.176.80) by DC5-EXCH01.marvell.com (10.69.176.38) with Microsoft SMTP Server id 15.0.1497.48 via Frontend Transport; Thu, 30 Nov 2023 08:25:26 -0800 Received: from dc3lp-swdev041.marvell.com (dc3lp-swdev041.marvell.com [10.6.60.191]) by maili.marvell.com (Postfix) with ESMTP id 237725C68E1; Thu, 30 Nov 2023 08:25:24 -0800 (PST) From: Elad Nachman To: , , , CC: , Subject: [PATCH] i2c: busses: i2c-mv64xxx: fix arb-loss i2c lock Date: Thu, 30 Nov 2023 18:25:22 +0200 Message-ID: <20231130162522.3306136-1-enachman@marvell.com> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Proofpoint-GUID: xn3xKQzE7k0usXjjbT04nSTza3-QiLdp X-Proofpoint-ORIG-GUID: xn3xKQzE7k0usXjjbT04nSTza3-QiLdp X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.997,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-11-30_16,2023-11-30_01,2023-05-22_02 From: Elad Nachman Some i2c slaves, mainly SFPs, might cause the bus to lose arbitration while slave is in the middle of responding. The solution is to change the I2C mode from mpps to gpios, and toggle the i2c_scl gpio to emulate bus clock toggling, so slave will finish its transmission, driven by the manual clock toggling, and will release the i2c bus. Signed-off-by: Elad Nachman --- drivers/i2c/busses/i2c-mv64xxx.c | 81 ++++++++++++++++++++++++++++++++ 1 file changed, 81 insertions(+) diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c index dc160cbc3155..21715f31dc29 100644 --- a/drivers/i2c/busses/i2c-mv64xxx.c +++ b/drivers/i2c/busses/i2c-mv64xxx.c @@ -26,6 +26,7 @@ #include #include #include +#include #define MV64XXX_I2C_ADDR_ADDR(val) ((val & 0x7f) << 1) #define MV64XXX_I2C_BAUD_DIV_N(val) (val & 0x7) @@ -104,6 +105,7 @@ enum { MV64XXX_I2C_ACTION_RCV_DATA, MV64XXX_I2C_ACTION_RCV_DATA_STOP, MV64XXX_I2C_ACTION_SEND_STOP, + MV64XXX_I2C_ACTION_UNLOCK_BUS }; struct mv64xxx_i2c_regs { @@ -150,6 +152,11 @@ struct mv64xxx_i2c_data { bool clk_n_base_0; struct i2c_bus_recovery_info rinfo; bool atomic; + /* I2C mpp states & gpios needed for arbitration lost recovery */ + int scl_gpio, sda_gpio; + bool arb_lost_recovery_ena; + struct pinctrl_state *i2c_mpp_state; + struct pinctrl_state *i2c_gpio_state; }; static struct mv64xxx_i2c_regs mv64xxx_i2c_regs_mv64xxx = { @@ -318,6 +325,11 @@ mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status) drv_data->state = MV64XXX_I2C_STATE_IDLE; break; + case MV64XXX_I2C_STATUS_MAST_LOST_ARB: /*0x38*/ + drv_data->action = MV64XXX_I2C_ACTION_UNLOCK_BUS; + drv_data->state = MV64XXX_I2C_STATE_IDLE; + break; + case MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK: /* 0x20 */ case MV64XXX_I2C_STATUS_MAST_WR_NO_ACK: /* 30 */ case MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK: /* 48 */ @@ -356,6 +368,9 @@ static void mv64xxx_i2c_send_start(struct mv64xxx_i2c_data *drv_data) static void mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data) { + struct pinctrl *pc; + int i, ret; + switch(drv_data->action) { case MV64XXX_I2C_ACTION_SEND_RESTART: /* We should only get here if we have further messages */ @@ -409,6 +424,48 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data) drv_data->reg_base + drv_data->reg_offsets.control); break; + case MV64XXX_I2C_ACTION_UNLOCK_BUS: + + if (!drv_data->arb_lost_recovery_ena) + break; + + pc = devm_pinctrl_get(drv_data->adapter.dev.parent); + if (IS_ERR(pc)) + break; + + /* Change i2c MPPs state to act as GPIOs: */ + if (pinctrl_select_state(pc, drv_data->i2c_gpio_state) >= 0) { + ret = devm_gpio_request_one(drv_data->adapter.dev.parent, + drv_data->scl_gpio, GPIOF_DIR_OUT, NULL); + ret |= devm_gpio_request_one(drv_data->adapter.dev.parent, + drv_data->sda_gpio, GPIOF_DIR_OUT, NULL); + if (!ret) { + /* Toggle i2c scl (serial clock) 10 times. + * This allows the slave that occupies + * the bus to transmit its remaining data, + * so it can release the i2c bus: + */ + for (i = 0; i < 10; i++) { + gpio_set_value(drv_data->scl_gpio, 1); + mdelay(1); + gpio_set_value(drv_data->scl_gpio, 0); + }; + + devm_gpiod_put(drv_data->adapter.dev.parent, + gpio_to_desc(drv_data->scl_gpio)); + devm_gpiod_put(drv_data->adapter.dev.parent, + gpio_to_desc(drv_data->sda_gpio)); + } + + /* restore i2c pin state to MPPs: */ + pinctrl_select_state(pc, drv_data->i2c_mpp_state); + } + + /* Trigger controller soft reset: */ + writel(0x1, drv_data->reg_base + drv_data->reg_offsets.soft_reset); + mdelay(1); + fallthrough; + case MV64XXX_I2C_ACTION_RCV_DATA_STOP: drv_data->msg->buf[drv_data->byte_posn++] = readl(drv_data->reg_base + drv_data->reg_offsets.data); @@ -985,6 +1042,7 @@ mv64xxx_i2c_probe(struct platform_device *pd) { struct mv64xxx_i2c_data *drv_data; struct mv64xxx_i2c_pdata *pdata = dev_get_platdata(&pd->dev); + struct pinctrl *pc; int rc; if ((!pdata && !pd->dev.of_node)) @@ -1040,6 +1098,29 @@ mv64xxx_i2c_probe(struct platform_device *pd) if (rc == -EPROBE_DEFER) return rc; + drv_data->arb_lost_recovery_ena = false; + pc = devm_pinctrl_get(&pd->dev); + if (!IS_ERR(pc)) { + drv_data->i2c_mpp_state = + pinctrl_lookup_state(pc, "default"); + drv_data->i2c_gpio_state = + pinctrl_lookup_state(pc, "gpio"); + drv_data->scl_gpio = + of_get_named_gpio(pd->dev.of_node, "scl-gpios", 0); + drv_data->sda_gpio = + of_get_named_gpio(pd->dev.of_node, "sda-gpios", 0); + + if (!IS_ERR(drv_data->i2c_gpio_state) && + !IS_ERR(drv_data->i2c_mpp_state) && + gpio_is_valid(drv_data->scl_gpio) && + gpio_is_valid(drv_data->sda_gpio)) + drv_data->arb_lost_recovery_ena = true; + } + + if (!drv_data->arb_lost_recovery_ena) + dev_info(&pd->dev, + "mv64xxx: missing arbitration-lost recovery definitions in dts file\n"); + drv_data->adapter.dev.parent = &pd->dev; drv_data->adapter.algo = &mv64xxx_i2c_algo; drv_data->adapter.owner = THIS_MODULE;