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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 D2F60C433DB for ; Tue, 22 Dec 2020 19:51:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A7E8A22ADC for ; Tue, 22 Dec 2020 19:51:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726039AbgLVTvj (ORCPT ); Tue, 22 Dec 2020 14:51:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32798 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725931AbgLVTvi (ORCPT ); Tue, 22 Dec 2020 14:51:38 -0500 Received: from mail-pl1-x62e.google.com (mail-pl1-x62e.google.com [IPv6:2607:f8b0:4864:20::62e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 89953C0613D6 for ; Tue, 22 Dec 2020 11:50:58 -0800 (PST) Received: by mail-pl1-x62e.google.com with SMTP id y8so7944347plp.8 for ; Tue, 22 Dec 2020 11:50:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=platinasystems-com.20150623.gappssmtp.com; s=20150623; h=from:to:subject:date:message-id:mime-version :content-transfer-encoding; bh=gnrWzcZcKCPPQwHRjj320KhXxSg0ErADEbe3H1rw//0=; b=gGUrUFMiw4JWsWifL0TXf2jyogF2W8pHnJa+hyI4msW+Mh9cnxp6FXcKIxFRNMD4Jj DH8BAGHgXF6wc4ZqBJzj2PVQzGyaZdAPRPBr77Ibt2uPXm6Wmgjl0i8G5MQt+jXDGHx1 EJRJN+g0KIrsQZP02GadFsj42H1BN/PBaNLuph4my0rmWq/xt3GF0AhQjCbK1Ght+hNT uAfsziMBPy9G4q/NfE0dknSHClk1pSZZjZLF+yCa/scL2yFYMfH1gtTYyLjTlfGfg89a n1jHUIsvZp9tXlP6b7HhmVQCzgUPXfv2OQlVzFEXYBSttDt6/XkQmYyOB4TaQ2BPLgeF PMZg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:mime-version :content-transfer-encoding; bh=gnrWzcZcKCPPQwHRjj320KhXxSg0ErADEbe3H1rw//0=; b=dLohhSIuq+qVEofk3CI4XgzZpkekw21ryuZw4GHxs9Tu1Fd2AMCuvr8cV+HCJOCfbD WkC6P6qADHcLqqEVLiuJG+/blMufR0Srg4RrphoJAPKSeOO0aInTrojDs4qfRK5pk0ZB +CoOBhTy2nMxo7x4v5eAIIz+qwILNOclAtujbxecGp/5xNfcaGdDJykWGt0Cr9pqjl5y U5RwrH4E1redjHl8DKg4fUL8m/HHgtJXMkBtcj7cBgJ/UgfIjJIE7pn+fUXcYFKIhKxd KaygYF8zSFNUydzPzA5Pfv9k4TbFdG2JRJ8Z/nULu0cpkVdV+NDpTmkscf8Qn+9U4nnt b4MA== X-Gm-Message-State: AOAM533Wzwu2LyDhvWrmL6iFNW9LjPLWzUqwbyqwX8Im0E8rh2hICXms u6la0ZLogoKW/LG5epaPaMGcSg== X-Google-Smtp-Source: ABdhPJwcc+tKiFWFDEimn0YEP31KJTEdUFiu3Aj7QQrs+YsH75VI7hSfoHDyKmNPOdLKF1L/tN9FdQ== X-Received: by 2002:a17:90a:8985:: with SMTP id v5mr22935126pjn.27.1608666657981; Tue, 22 Dec 2020 11:50:57 -0800 (PST) Received: from localhost.localdomain ([207.53.255.56]) by smtp.gmail.com with ESMTPSA id b72sm20770253pfb.129.2020.12.22.11.50.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 22 Dec 2020 11:50:57 -0800 (PST) From: Kevin Paul Herbert To: biwen.li@nxp.com, leoyang.li@nxp.com, linux@rempel-privat.de, kernel@pengutronix.de, wsa@the-dreams.de, shawnguo@kernel.org, s.hauer@pengutronix.de, festevam@gmail.com, aisheng.dong@nxp.com, xiaoning.wang@nxp.com, o.rempel@pengutronix.de, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, jiafei.pan@nxp.com, xiaobo.xie@nxp.com, linux-arm-kernel@lists.infradead.org, biwen.li@oss.nxp.com, kph@platinasystems.com Subject: [PATCH] i2c-imx.c: Synthesize end of transaction events without idle interrupts Date: Tue, 22 Dec 2020 11:48:50 -0800 Message-Id: <20201222194850.2274527-1-kph@platinasystems.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Only the Layerscape SoCs have interrupts on bus idle, which facilitate sending events which complete slave bus transactions. Add support for synthesizing missing events. If we see a master request, or a newly addressed slave request, if the last event sent to the backend was I2C_SLAVE_READ_REQUESTED, send the backend a I2C_SLAVE_READ_PROCESSED followed by I2C_SLAVE_STOP. For all other events, send an I2C_SLAVE_STOP. Signed-off-by: Kevin Paul Herbert --- drivers/i2c/busses/i2c-imx.c | 59 +++++++++++++++++++++++++++++++----- 1 file changed, 52 insertions(+), 7 deletions(-) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index b444fbf1a262..b3e2a6a7fc19 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -209,6 +209,7 @@ struct imx_i2c_struct { struct imx_i2c_dma *dma; struct i2c_client *slave; + enum i2c_slave_event last_slave_event; }; static const struct imx_i2c_hwdata imx1_i2c_hwdata = { @@ -662,6 +663,36 @@ static void i2c_imx_enable_bus_idle(struct imx_i2c_struct *i2c_imx) } } +static void i2c_imx_slave_event(struct imx_i2c_struct *i2c_imx, + enum i2c_slave_event event, u8 *val) +{ + i2c_slave_event(i2c_imx->slave, event, val); + i2c_imx->last_slave_event = event; +} + +static void i2c_imx_slave_finish_op(struct imx_i2c_struct *i2c_imx) +{ + u8 val; + + while (i2c_imx->last_slave_event != I2C_SLAVE_STOP) { + switch (i2c_imx->last_slave_event) { + case I2C_SLAVE_READ_REQUESTED: + i2c_imx_slave_event(i2c_imx, I2C_SLAVE_READ_PROCESSED, + &val); + break; + + case I2C_SLAVE_WRITE_REQUESTED: + case I2C_SLAVE_READ_PROCESSED: + case I2C_SLAVE_WRITE_RECEIVED: + i2c_imx_slave_event(i2c_imx, I2C_SLAVE_STOP, &val); + break; + + case I2C_SLAVE_STOP: + break; + } + } +} + static irqreturn_t i2c_imx_slave_isr(struct imx_i2c_struct *i2c_imx, unsigned int status, unsigned int ctl) { @@ -674,9 +705,11 @@ static irqreturn_t i2c_imx_slave_isr(struct imx_i2c_struct *i2c_imx, } if (status & I2SR_IAAS) { /* Addressed as a slave */ + i2c_imx_slave_finish_op(i2c_imx); if (status & I2SR_SRW) { /* Master wants to read from us*/ dev_dbg(&i2c_imx->adapter.dev, "read requested"); - i2c_slave_event(i2c_imx->slave, I2C_SLAVE_READ_REQUESTED, &value); + i2c_imx_slave_event(i2c_imx, + I2C_SLAVE_READ_REQUESTED, &value); /* Slave transmit */ ctl |= I2CR_MTX; @@ -686,7 +719,8 @@ static irqreturn_t i2c_imx_slave_isr(struct imx_i2c_struct *i2c_imx, imx_i2c_write_reg(value, i2c_imx, IMX_I2C_I2DR); } else { /* Master wants to write to us */ dev_dbg(&i2c_imx->adapter.dev, "write requested"); - i2c_slave_event(i2c_imx->slave, I2C_SLAVE_WRITE_REQUESTED, &value); + i2c_imx_slave_event(i2c_imx, + I2C_SLAVE_WRITE_REQUESTED, &value); /* Slave receive */ ctl &= ~I2CR_MTX; @@ -697,17 +731,20 @@ static irqreturn_t i2c_imx_slave_isr(struct imx_i2c_struct *i2c_imx, } else if (!(ctl & I2CR_MTX)) { /* Receive mode */ if (status & I2SR_IBB) { /* No STOP signal detected */ value = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); - i2c_slave_event(i2c_imx->slave, I2C_SLAVE_WRITE_RECEIVED, &value); + i2c_imx_slave_event(i2c_imx, + I2C_SLAVE_WRITE_RECEIVED, &value); } else { /* STOP signal is detected */ dev_dbg(&i2c_imx->adapter.dev, "STOP signal detected"); - i2c_slave_event(i2c_imx->slave, I2C_SLAVE_STOP, &value); + i2c_imx_slave_event(i2c_imx, + I2C_SLAVE_STOP, &value); } } else if (!(status & I2SR_RXAK)) { /* Transmit mode received ACK */ ctl |= I2CR_MTX; imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); - i2c_slave_event(i2c_imx->slave, I2C_SLAVE_READ_PROCESSED, &value); + i2c_imx_slave_event(i2c_imx, + I2C_SLAVE_READ_PROCESSED, &value); imx_i2c_write_reg(value, i2c_imx, IMX_I2C_I2DR); } else { /* Transmit mode received NAK */ @@ -748,6 +785,7 @@ static int i2c_imx_reg_slave(struct i2c_client *client) return -EBUSY; i2c_imx->slave = client; + i2c_imx->last_slave_event = I2C_SLAVE_STOP; /* Resume */ ret = pm_runtime_get_sync(i2c_imx->adapter.dev.parent); @@ -800,10 +838,17 @@ static irqreturn_t i2c_imx_isr(int irq, void *dev_id) status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); + if (status & I2SR_IIF) { i2c_imx_clear_irq(i2c_imx, I2SR_IIF); - if (i2c_imx->slave && !(ctl & I2CR_MSTA)) - return i2c_imx_slave_isr(i2c_imx, status, ctl); + if (i2c_imx->slave) { + if (!(ctl & I2CR_MSTA)) { + return i2c_imx_slave_isr(i2c_imx, status, ctl); + } else if (i2c_imx->last_slave_event != + I2C_SLAVE_STOP) { + i2c_imx_slave_finish_op(i2c_imx); + } + } return i2c_imx_master_isr(i2c_imx, status); } -- 2.25.1