From patchwork Mon Sep 2 07:42:01 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Eichenberger X-Patchwork-Id: 13786869 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id C13F7CD13CF for ; Mon, 2 Sep 2024 07:45:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ZpFUa0HNPaA1/z3K1YQrq6JjQoT/x4qwWIkq9q1c5wM=; b=bxNw26GEui4yY1RZf1wXEMWFbc ccGldnDhD/UCr1J2SGk6B3cLQizizR7OmleQrYJWlyij341oIpnSAQ879SlBzq7smlDSfCz2sYtIg Hthv3wE/p6KdpYBErH8y24rsbFyKNzC6+bOBaJbhTrAJMons68Xkd5VZMR87IQ5uZkXHdjjGKuQ8P dluJ+T6DgNOpEiwFCynMnqGXxxQaTT8pfacaaUYMYJxl/1mkZIXXcYCublMZqlCEbMjIfoNYrTFci k64VzHjvtj3/oGA+FU68a++pq5MykiF94LqcGT4/WDcaxhYaeVxecC81b1grVrN3q+m2hnBSIxhok Y6fuYrbQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sl1kZ-0000000DMLg-3zkw; Mon, 02 Sep 2024 07:45:24 +0000 Received: from mail-ed1-x529.google.com ([2a00:1450:4864:20::529]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sl1ir-0000000DLuh-09xq for linux-arm-kernel@lists.infradead.org; Mon, 02 Sep 2024 07:43:38 +0000 Received: by mail-ed1-x529.google.com with SMTP id 4fb4d7f45d1cf-58ef19aa69dso3540519a12.3 for ; Mon, 02 Sep 2024 00:43:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1725263015; x=1725867815; darn=lists.infradead.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=ZpFUa0HNPaA1/z3K1YQrq6JjQoT/x4qwWIkq9q1c5wM=; b=mf90fLootqg6GqBw1+Ba2cQ29ylOlByaZeWz5954clwyV2PkWMRDDzmXLdsmoUYqQA OAVg0nAYG3nXAQtsR/VtypX4I3x0xJTYjomfLIGSuK2zzoGAarazT2zSpVUoGeNHK//i Ti7XRhhS/r+HhDSGvtC22r1cun6+QoxoZFswbV3RD8p07YUk/DssE0nWCfJZZRnWHP81 H3Ik1FcUUJwQv0zyfggCvrzUtLJIPwlJnNd2X/5tZEOm6jJ23rhKk1CzoRu6OhYsoa4z b6qNVHz9IBRRHruGa9xS+vkgkKEQ3o0JOV7NNeffSYTZF8naujbZr0mcS2BFVZUN2zOO N2TA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1725263015; x=1725867815; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=ZpFUa0HNPaA1/z3K1YQrq6JjQoT/x4qwWIkq9q1c5wM=; b=b/WfDoFoOg40dfC9tQv8e4hv/1N1ujYS8hhedepLlHHfU9Iq0IBUNInNK7eJHqTQAb WhD//HhezAGZlyjjWfahcAFiQ4fRfTI29rL8FZ1nFNeTx4iKpxMxS2MW+yGkiAF6j2Oj txxqRYIxx4wqgqY6nnd1mIEIKxwCoemSuRsDQahUCt6NTFq/ZF1ojIl/rq4w/4ClkJ9C +vSIFNmEo4ykTkUGyLiJ45y5t+fhNRj4BNZayEbr2oDVQbly1XBjgRqnaZZeMzap35ZB vSeE/yb5rKdLZZTlxgn+R3v7HZoy+nBuWayxOhmjmOlCTxSxtVsuOlu5AvVmVpkE5bg8 vAXw== X-Forwarded-Encrypted: i=1; AJvYcCXBAk3AqeHy17b0lMTipWK+DBrblI9bAAm+GBHGiU30NpkXbzD3HL2gTPtbm0aLZ8W8iMArLX2/KJF6tRsKhiic@lists.infradead.org X-Gm-Message-State: AOJu0YyYsQES8Rr5LHTxSGzdAPSja8lk7s7ZSec/s7uQyaHq2qJh8Y2x S/xdrrf0wuv7hk7initJ8Bh3fl6gf13CZhF/LWHuQbV0qS1uEqrX X-Google-Smtp-Source: AGHT+IGXhpPe+w6G0FeAT/iHfSIhFVsjo1uLMmtN+ZLdNG28sLEI6fGLHqIbur3Zw3B584wVE2jslw== X-Received: by 2002:a05:6402:5215:b0:5c2:5620:f7c with SMTP id 4fb4d7f45d1cf-5c256201165mr2046949a12.18.1725263015146; Mon, 02 Sep 2024 00:43:35 -0700 (PDT) Received: from eichest-laptop.lan ([2a02:168:af72:0:3786:cf07:4865:dc9f]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-5c24ff04551sm1975931a12.35.2024.09.02.00.43.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Sep 2024 00:43:34 -0700 (PDT) From: Stefan Eichenberger To: o.rempel@pengutronix.de, kernel@pengutronix.de, andi.shyti@kernel.org, shawnguo@kernel.org, s.hauer@pengutronix.de, festevam@gmail.com, francesco.dolcini@toradex.com, Frank.Li@nxp.com Cc: linux-i2c@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Stefan Eichenberger Subject: [PATCH v3 1/4] i2c: imx: only poll for bus busy in multi master mode Date: Mon, 2 Sep 2024 09:42:01 +0200 Message-ID: <20240902074330.6349-2-eichest@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240902074330.6349-1-eichest@gmail.com> References: <20240902074330.6349-1-eichest@gmail.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240902_004337_100923_F2C150C9 X-CRM114-Status: GOOD ( 16.01 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Stefan Eichenberger According to the i.MX8M Mini reference manual chapter "16.1.4.2 Generation of Start" it is only necessary to poll for bus busy and arbitration lost in multi master mode. This helps to avoid rescheduling while the i2c bus is busy and avoids SMBus devices to timeout. Signed-off-by: Stefan Eichenberger Reviewed-by: Frank Li Acked-by: Oleksij Rempel --- drivers/i2c/busses/i2c-imx.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 3842e527116b7..1add946e3bc20 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -216,6 +216,8 @@ struct imx_i2c_struct { struct i2c_client *slave; enum i2c_slave_event last_slave_event; + bool multi_master; + /* For checking slave events. */ spinlock_t slave_lock; struct hrtimer slave_timer; @@ -481,6 +483,9 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy, bool a unsigned long orig_jiffies = jiffies; unsigned int temp; + if (!i2c_imx->multi_master) + return 0; + while (1) { temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); @@ -540,8 +545,8 @@ static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx, bool atomic) return -ETIMEDOUT; } - /* check for arbitration lost */ - if (i2c_imx->i2csr & I2SR_IAL) { + /* In multi-master mode check for arbitration lost */ + if (i2c_imx->multi_master && (i2c_imx->i2csr & I2SR_IAL)) { dev_dbg(&i2c_imx->adapter.dev, "<%s> Arbitration lost\n", __func__); i2c_imx_clear_irq(i2c_imx, I2SR_IAL); @@ -1468,6 +1473,8 @@ static int i2c_imx_probe(struct platform_device *pdev) goto rpm_disable; } + i2c_imx->multi_master = of_property_read_bool(pdev->dev.of_node, "multi-master"); + /* Set up clock divider */ i2c_imx->bitrate = I2C_MAX_STANDARD_MODE_FREQ; ret = of_property_read_u32(pdev->dev.of_node, From patchwork Mon Sep 2 07:42:02 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Eichenberger X-Patchwork-Id: 13786870 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 2206ECD13CF for ; Mon, 2 Sep 2024 07:46:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=GhXn8yzBmBetRaq5gwnzPTgSSOE3n3HbgWNjkP9ceck=; b=0s5Cua01gF6hdK1+QMBS1N+prc 0pKMpC7oN7ZJzhvKaWU6q+Z4JH+0NP7jC1xxSMYruhO+8Xx7gaqe1GPxC+ihB6NCWRwNRo28c0ihQ 98vqQ3vuoXbakXr0CTqtaGe1LcNKfDEYtf1u50milrZrORbgppPa34wL9IZWTDcjwLe1HP0HmJE6P 8qesRIernGuSE1QMFBGFnInKmFx0pjbaWeRnOEjYTf++VHF8BcnubP83kjhJyEaGfTf8Szjh1HDnH 79YO7MKUQTI3AZdXzAk8b3J9jlYs8IuqDHBKDvuF1Js/Q5xwEY7xpedhzSsJzNdzkXS0wfHiCl6HG /0pHAJmA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sl1lP-0000000DMSN-3Y52; Mon, 02 Sep 2024 07:46:16 +0000 Received: from mail-ed1-x533.google.com ([2a00:1450:4864:20::533]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sl1ir-0000000DLui-3lfz for linux-arm-kernel@lists.infradead.org; Mon, 02 Sep 2024 07:43:39 +0000 Received: by mail-ed1-x533.google.com with SMTP id 4fb4d7f45d1cf-5bef295a429so4049331a12.2 for ; Mon, 02 Sep 2024 00:43:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1725263016; x=1725867816; darn=lists.infradead.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=GhXn8yzBmBetRaq5gwnzPTgSSOE3n3HbgWNjkP9ceck=; b=SC18boPMRV6Umt/E3xFUXAFC0mK5ax6de3PHS9z1btgu53H8f5lMx2lEr1lSp8yW0L xuyCMJL0iA0UtB0Y5AdQCRUuhw6bTkRvk18Dj/cbaBlFDmEpbqANTkgu90O/5F8PHsJJ CYWZlCA4nvctONxUAoSLaQwVaoDWvZeGedEcJqrzDObBxsLSiOerLixwDVOVcRJKMXx0 l4pooHZWxJ/S1cHAlKYv6NNBDBdMUFF3jG4blaVTT3qh/CchKkIz5yN6VmlUwuXaflQP eDKxArBrpc1kKFfBci5dJlBuCSEiHSTXCq493M7TDOsIWOgMtgkOx9n3Rofr4oRHGeGC y4+Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1725263016; x=1725867816; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=GhXn8yzBmBetRaq5gwnzPTgSSOE3n3HbgWNjkP9ceck=; b=mteUTr/nIVrapgC0C+td32FdrFsfSWb0Gpl2HIiREU/+JoZNLwArUNRFHJqjHeisGp 6mV13LjiEV2Erpyyyh4mhjprTklQqNyX5LmdPOV6siTBrhSwk0lI6SXGRcD4f/MQLXHO Pj2p+l8chruJ1plhq+WxalDE3vaLS/NnUjwyhovK4Z9gd4z3XwtFvHva/xnEnGyuWMiG ZZJl+ZsSbC5p1TXSqhiCK0xhHMnwhv4lmzXkqVNKKpAg/LigJGno9U8DgfsPSNzFoYOP JQTgPgNiyCfjMRq9NBrOgoQRdtX31VS8tOA5sw7mczytx3KfKyrsBMawXBHQYh41rgBS dczg== X-Forwarded-Encrypted: i=1; AJvYcCUtzMkfryavAN6r5AJgjLIB/ZOF/3jJ5+LgM00pMLxRthMmAe47ulxWe0gOBBeEDXbVu7sU82hefoCdrosIWhDM@lists.infradead.org X-Gm-Message-State: AOJu0Yw3gccAMVoyCqRfwbSVeANlRMMi3K4MdGjHC6j1Y7BkusURyqd3 2763FSErNbpa+oADJ4q1RWWLyFpMfzw5g72Ldk19weu/Ays3gqhj X-Google-Smtp-Source: AGHT+IHiDu66PFT4NbI9XCCDykJ+zbc3l+Z3gf+wyx1pxTHnxU/1Kf6dpoiZq5hhs53tpTHzDM/f6g== X-Received: by 2002:a05:6402:4310:b0:5a2:2654:7fc4 with SMTP id 4fb4d7f45d1cf-5c25c3a717amr2166864a12.8.1725263015871; Mon, 02 Sep 2024 00:43:35 -0700 (PDT) Received: from eichest-laptop.lan ([2a02:168:af72:0:3786:cf07:4865:dc9f]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-5c24ff04551sm1975931a12.35.2024.09.02.00.43.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Sep 2024 00:43:35 -0700 (PDT) From: Stefan Eichenberger To: o.rempel@pengutronix.de, kernel@pengutronix.de, andi.shyti@kernel.org, shawnguo@kernel.org, s.hauer@pengutronix.de, festevam@gmail.com, francesco.dolcini@toradex.com, Frank.Li@nxp.com Cc: linux-i2c@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Stefan Eichenberger Subject: [PATCH v3 2/4] i2c: imx: separate atomic, dma and non-dma use case Date: Mon, 2 Sep 2024 09:42:02 +0200 Message-ID: <20240902074330.6349-3-eichest@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240902074330.6349-1-eichest@gmail.com> References: <20240902074330.6349-1-eichest@gmail.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240902_004337_964636_0F60E962 X-CRM114-Status: GOOD ( 21.20 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Stefan Eichenberger Separate the atomic, dma and non-dma use case as a preparation step for moving the non-dma use case to the isr to avoid rescheduling while a transfer is in progress. Signed-off-by: Stefan Eichenberger Reviewed-by: Frank Li Acked-by: Oleksij Rempel --- drivers/i2c/busses/i2c-imx.c | 107 +++++++++++++++++++++++------------ 1 file changed, 70 insertions(+), 37 deletions(-) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 1add946e3bc20..2e86d363e186d 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -1011,6 +1011,43 @@ static int i2c_imx_dma_write(struct imx_i2c_struct *i2c_imx, return i2c_imx_acked(i2c_imx); } +static int i2c_imx_prepare_read(struct imx_i2c_struct *i2c_imx, + struct i2c_msg *msgs, bool atomic, + bool use_dma) +{ + int result; + unsigned int temp = 0; + + /* write slave address */ + imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR); + result = i2c_imx_trx_complete(i2c_imx, atomic); + if (result) + return result; + result = i2c_imx_acked(i2c_imx); + if (result) + return result; + + dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__); + + /* setup bus to read data */ + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); + temp &= ~I2CR_MTX; + + /* + * Reset the I2CR_TXAK flag initially for SMBus block read since the + * length is unknown + */ + if (msgs->len - 1) + temp &= ~I2CR_TXAK; + if (use_dma) + temp |= I2CR_DMAEN; + + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); + imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); /* dummy read */ + + return 0; +} + static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bool is_lastmsg) { @@ -1021,6 +1058,11 @@ static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx, struct imx_i2c_dma *dma = i2c_imx->dma; struct device *dev = &i2c_imx->adapter.dev; + result = i2c_imx_prepare_read(i2c_imx, msgs, false, true); + if (result) + return result; + + dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__); dma->chan_using = dma->chan_rx; dma->dma_transfer_dir = DMA_DEV_TO_MEM; @@ -1131,50 +1173,24 @@ static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, return 0; } +static int i2c_imx_atomic_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs) +{ + return i2c_imx_write(i2c_imx, msgs, true); +} + static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bool is_lastmsg, bool atomic) { int i, result; unsigned int temp; int block_data = msgs->flags & I2C_M_RECV_LEN; - int use_dma = i2c_imx->dma && msgs->flags & I2C_M_DMA_SAFE && - msgs->len >= DMA_THRESHOLD && !block_data; - dev_dbg(&i2c_imx->adapter.dev, - "<%s> write slave address: addr=0x%x\n", - __func__, i2c_8bit_addr_from_msg(msgs)); - - /* write slave address */ - imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR); - result = i2c_imx_trx_complete(i2c_imx, atomic); + result = i2c_imx_prepare_read(i2c_imx, msgs, atomic, false); if (result) return result; - result = i2c_imx_acked(i2c_imx); - if (result) - return result; - - dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__); - - /* setup bus to read data */ - temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); - temp &= ~I2CR_MTX; - - /* - * Reset the I2CR_TXAK flag initially for SMBus block read since the - * length is unknown - */ - if ((msgs->len - 1) || block_data) - temp &= ~I2CR_TXAK; - if (use_dma) - temp |= I2CR_DMAEN; - imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); - imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); /* dummy read */ dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__); - if (use_dma) - return i2c_imx_dma_read(i2c_imx, msgs, is_lastmsg); - /* read data */ for (i = 0; i < msgs->len; i++) { u8 len = 0; @@ -1241,6 +1257,12 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, return 0; } +static int i2c_imx_atomic_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, + bool is_lastmsg) +{ + return i2c_imx_read(i2c_imx, msgs, is_lastmsg, true); +} + static int i2c_imx_xfer_common(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num, bool atomic) { @@ -1248,6 +1270,7 @@ static int i2c_imx_xfer_common(struct i2c_adapter *adapter, int result; bool is_lastmsg = false; struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter); + int use_dma = 0; /* Start I2C transfer */ result = i2c_imx_start(i2c_imx, atomic); @@ -1300,15 +1323,25 @@ static int i2c_imx_xfer_common(struct i2c_adapter *adapter, (temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0), (temp & I2SR_RXAK ? 1 : 0)); #endif + + use_dma = i2c_imx->dma && msgs[i].len >= DMA_THRESHOLD && + msgs[i].flags & I2C_M_DMA_SAFE; if (msgs[i].flags & I2C_M_RD) { - result = i2c_imx_read(i2c_imx, &msgs[i], is_lastmsg, atomic); + int block_data = msgs->flags & I2C_M_RECV_LEN; + + if (atomic) + result = i2c_imx_atomic_read(i2c_imx, &msgs[i], is_lastmsg); + else if (use_dma && !block_data) + result = i2c_imx_dma_read(i2c_imx, &msgs[i], is_lastmsg); + else + result = i2c_imx_read(i2c_imx, &msgs[i], is_lastmsg, false); } else { - if (!atomic && - i2c_imx->dma && msgs[i].len >= DMA_THRESHOLD && - msgs[i].flags & I2C_M_DMA_SAFE) + if (atomic) + result = i2c_imx_atomic_write(i2c_imx, &msgs[i]); + else if (use_dma) result = i2c_imx_dma_write(i2c_imx, &msgs[i]); else - result = i2c_imx_write(i2c_imx, &msgs[i], atomic); + result = i2c_imx_write(i2c_imx, &msgs[i], false); } if (result) goto fail0; From patchwork Mon Sep 2 07:42:03 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Eichenberger X-Patchwork-Id: 13786871 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id EC72BCD13CF for ; Mon, 2 Sep 2024 07:47:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=M6uJEhYo1wgA15wfbrz/2U4r9R3nPVkJpmSXzlK2nlI=; b=19ak5NxWd5S7KhPg9f+to+TI4P LnpZr+15yKyBLcsk+TJL5ghh/JNAMCD6PA6jGpc2wqkean3CCg2U2sayik4dQdnB+pCiEGqu3XOza 1WuaawVLDXD8i/Bdpb4atjEcZuB0Nsb0DkrCPw+gdNb2hY/JhdCCsQB/ltv8Yb3oZby7NSHbZ8Rlc 00oYtVd5Mypfg5Klu/UsQ0P4UxPooSRvvmwUve9QMIgEVQFKRsHVfV6zWA1/anP4E39Zl19dR2nY7 DWJiQbTslxkwO/hrGtm8A6AzLHxNSiOcqOiAvRUhEOsukpJHu6UEDs+lpt34h82ilkOfLheoATfp0 kNe5NWiw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sl1mH-0000000DMe8-1kFq; Mon, 02 Sep 2024 07:47:09 +0000 Received: from mail-ed1-x52b.google.com ([2a00:1450:4864:20::52b]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sl1is-0000000DLux-2ojg for linux-arm-kernel@lists.infradead.org; Mon, 02 Sep 2024 07:43:39 +0000 Received: by mail-ed1-x52b.google.com with SMTP id 4fb4d7f45d1cf-5c25f01879fso535439a12.1 for ; Mon, 02 Sep 2024 00:43:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1725263017; x=1725867817; darn=lists.infradead.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=M6uJEhYo1wgA15wfbrz/2U4r9R3nPVkJpmSXzlK2nlI=; b=jT6uJac81S967QGxnbcrweJYrtljHUZAaWUmcdoBgDrYr4pQGYscIPra+SGtmtkFqI RlR8LAIhMwRTY39SFnp0l0BhfcS8Mp18Q5PSQdyl2XlZYc9uxfC5gRbqvpS0dgfzHppL CRbNjOmPdYaYvMt3+xMtX3atFRX/kXjZBmamEQNQvGsdsV1MdsihKUryeOtZGH9RlqhK /cNcIfSZUJPLpIvxmnmgLrScN9TBMp75XUTIlVchmT8fVCNwtmhwYqMJHm6rKHPvpSC4 6T7JIWDMKdxupABerJQI8fe5mazm6bT5H+i6NUwxpMNqJK15QDLl5trCD52m8GBSHHX1 iR2A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1725263017; x=1725867817; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=M6uJEhYo1wgA15wfbrz/2U4r9R3nPVkJpmSXzlK2nlI=; b=dQrQ6pfWu0zswuFQD8Dga7ksCXgWTxBjbAojse1TiiXEMhnM+8gF+fhJvN8cw95DJ9 VsnotLfEI+2hoYMlL3vzg6++oDBcnJ0NV+C2y+0ZnKD9KjlD5+s3jyq2IyDUm8YEF1cY ANuQ7BM8esIA+Vi5A2AW3/QEhctNNvbs2+i5kqpVhYGCzg3rzqkav8yBBtgAOw2IjsBD P8Xpz81xQLzaJudjOb5MA/k1o+npip+Xp0s/xxG7ZnpEqpEzaXKG2PaMH7mDdbC+b7Gh AsWYkGby5cX+5L8BzBj6X7moQ+kloyJXqHMzXvZDlghBS03/KsioDkPTfg2eNetwfSl6 gGiw== X-Forwarded-Encrypted: i=1; AJvYcCX1wJ+2stdqo/5F1yzvzKysAJmXHZHeeCwxDRvauLbve6qdUQpiDm2AT8H/YiAQuk4A8sx8KrMNB2IXC1vKKdGU@lists.infradead.org X-Gm-Message-State: AOJu0Yx3UoNMCTQXvw8Wu18MVmLqvVe+2OxyDYSB0pGmCCCnaVtafGwS 2Gh1sET++i3OQVOhtk6GqZT3mnYzPlR1f0gCt3q8vahjtt/wpwnW X-Google-Smtp-Source: AGHT+IF+gPp7Guk0AwVW4KWTtsV4XPy/sheRsdCIms+DFiV6eNdF0CbTkwUp9ipAFhx6UBzgr4w99g== X-Received: by 2002:a05:6402:35c4:b0:5c2:2ba2:6841 with SMTP id 4fb4d7f45d1cf-5c24236d23bmr4206113a12.20.1725263016697; Mon, 02 Sep 2024 00:43:36 -0700 (PDT) Received: from eichest-laptop.lan ([2a02:168:af72:0:3786:cf07:4865:dc9f]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-5c24ff04551sm1975931a12.35.2024.09.02.00.43.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Sep 2024 00:43:36 -0700 (PDT) From: Stefan Eichenberger To: o.rempel@pengutronix.de, kernel@pengutronix.de, andi.shyti@kernel.org, shawnguo@kernel.org, s.hauer@pengutronix.de, festevam@gmail.com, francesco.dolcini@toradex.com, Frank.Li@nxp.com Cc: linux-i2c@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Stefan Eichenberger Subject: [PATCH v3 3/4] i2c: imx: use readb_relaxed and writeb_relaxed Date: Mon, 2 Sep 2024 09:42:03 +0200 Message-ID: <20240902074330.6349-4-eichest@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240902074330.6349-1-eichest@gmail.com> References: <20240902074330.6349-1-eichest@gmail.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240902_004338_748111_B2B561BC X-CRM114-Status: GOOD ( 14.90 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Stefan Eichenberger Use the relaxed version of readb and writeb to reduce overhead. It is safe to use the relaxed version because we either do not rely on dma completion, or we use a dma callback to ensure that the dma transfer is complete before we continue. Signed-off-by: Stefan Eichenberger Acked-by: Oleksij Rempel --- drivers/i2c/busses/i2c-imx.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 2e86d363e186d..9917f3e1d06cf 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -313,13 +313,13 @@ static inline int is_vf610_i2c(struct imx_i2c_struct *i2c_imx) static inline void imx_i2c_write_reg(unsigned int val, struct imx_i2c_struct *i2c_imx, unsigned int reg) { - writeb(val, i2c_imx->base + (reg << i2c_imx->hwdata->regshift)); + writeb_relaxed(val, i2c_imx->base + (reg << i2c_imx->hwdata->regshift)); } static inline unsigned char imx_i2c_read_reg(struct imx_i2c_struct *i2c_imx, unsigned int reg) { - return readb(i2c_imx->base + (reg << i2c_imx->hwdata->regshift)); + return readb_relaxed(i2c_imx->base + (reg << i2c_imx->hwdata->regshift)); } static void i2c_imx_clear_irq(struct imx_i2c_struct *i2c_imx, unsigned int bits) From patchwork Mon Sep 2 07:42:04 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Eichenberger X-Patchwork-Id: 13786874 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id D1108CD13CF for ; Mon, 2 Sep 2024 07:48:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=jySPRYvjH3UvU4UXnIxj7aqN4cvIDF3QR6dmwmZylts=; b=kzNoa58+4mtAJlTep8/H+fUC3H 1X4vbDtnwNmaYe2Febc+r8sVvPVqj6afktN/rMzKI0u4kS1Q3FUdaukBtXdprdfL191Mv8fD2wLxt 3kr+8mKdyBvOTkD3kIXTEccGaih7ccTs/dv6EtL8qAFD4ESuoaNbO1xiY5dzdR2Q6Negn8wyP6+Bw ylNZj9lX+B6UcPZj+MCsbk9R9N9guv2P729NkldoopoAjLmen6+278EF8cBl2ImDtkQZIRF1BiwzH BTMCsFYlTy/T7L0C7rt7sb0kyQVp0EEeSU50zqDIWwTEFRUoRGj+r4iGnXSqsFpmn+8b50r5ijxU7 W4I6otGg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sl1n8-0000000DMnQ-1OLx; Mon, 02 Sep 2024 07:48:02 +0000 Received: from mail-ed1-x52e.google.com ([2a00:1450:4864:20::52e]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sl1iu-0000000DLvf-1KRX for linux-arm-kernel@lists.infradead.org; Mon, 02 Sep 2024 07:43:41 +0000 Received: by mail-ed1-x52e.google.com with SMTP id 4fb4d7f45d1cf-5c25f01879fso535465a12.1 for ; Mon, 02 Sep 2024 00:43:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1725263018; x=1725867818; darn=lists.infradead.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=jySPRYvjH3UvU4UXnIxj7aqN4cvIDF3QR6dmwmZylts=; b=FU/1FI2LaG+nkRhMclSZ9+EXXZ2e1Av68+EotsjBoBTwmBoAo7GcBAnT+emUZGW4ih qNyqkVqvKh8gCgEQWKlJlINVmWJI1ayUzkQe4BvCogyL7um93ZAU17JfwWpLhG8MaATp kxwYNrtb5Dq8Mscyp9vix2KenNDQxOYKMt63YajLMl/VBJfdQSe65rHPBZ3XaQtQeSQJ zFcFMih/kE7ky2e5HxhDOFgA2LK24m3VS0DLjX5O/cShANR9yuyx3CQ3FlmprQMTcG/I /OdnUL49OOm52vsiBaAkZRsszW4/vUqgLLE2tt2Bj2FMESlmNPugss42wSjItNVpZHbl mV1Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1725263018; x=1725867818; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=jySPRYvjH3UvU4UXnIxj7aqN4cvIDF3QR6dmwmZylts=; b=sHjofyJWS98dUP2NwwnmYXFCgSlHZdkyRlxESykTbBBWkmIg/OZd4VLsNyJIt+Bw9B Q7xzk/GLT2qO5IG9pzgR910qkMvE1FQBlf50+Tz39u2ug2uey/k0519+4INhoJQ/xHkm FkqV4q00tMszvwQCevSjNFzeS8t9uc2CTUjiQJPfeZSydzbettCPLLFYlNN2LflIaOsJ Z9VZRrNlaxJLSjXSjG6TN25UBD+odKuO3Cum25sUapFdCaIrvH980HMOcWma9AYJoM+g 8UtSthDLFvBJ7bztTIYGSTRWMNsmqUB/M18eyAhFw8H84hVOdujbcmg+y0pzVzkl7Ei7 snwA== X-Forwarded-Encrypted: i=1; AJvYcCWDFMZz/LTI/YAJKAQlShmZN5EBP9fQvV/5qPQXgbv1aAEmlAVM/1mTgg2Q98mX4bhAut93ceHyr4bgE4hA8TJG@lists.infradead.org X-Gm-Message-State: AOJu0Yzl2x4cIQtuGBq0QY63XbPuKz4XtHuD2N5s9sGa/37RuR3zs0+C 7CSSlFPme0SFwgfDepF1y8Pr2s3pUFsIuULQ349Bw5Pbwaqh3D0/ X-Google-Smtp-Source: AGHT+IFK8mCYmRiOtmZ9hVjnSKrsFsOG4G2/5YwCjBLk3rIg37tL0PQu9ND0kuvSyVytOJDK/PnGKA== X-Received: by 2002:a05:6402:3593:b0:5bf:2ea:f0d3 with SMTP id 4fb4d7f45d1cf-5c242350997mr4847740a12.4.1725263018358; Mon, 02 Sep 2024 00:43:38 -0700 (PDT) Received: from eichest-laptop.lan ([2a02:168:af72:0:3786:cf07:4865:dc9f]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-5c24ff04551sm1975931a12.35.2024.09.02.00.43.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Sep 2024 00:43:37 -0700 (PDT) From: Stefan Eichenberger To: o.rempel@pengutronix.de, kernel@pengutronix.de, andi.shyti@kernel.org, shawnguo@kernel.org, s.hauer@pengutronix.de, festevam@gmail.com, francesco.dolcini@toradex.com, Frank.Li@nxp.com Cc: linux-i2c@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Stefan Eichenberger Subject: [PATCH v3 4/4] i2c: imx: prevent rescheduling in non dma mode Date: Mon, 2 Sep 2024 09:42:04 +0200 Message-ID: <20240902074330.6349-5-eichest@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240902074330.6349-1-eichest@gmail.com> References: <20240902074330.6349-1-eichest@gmail.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240902_004340_395640_E55736AF X-CRM114-Status: GOOD ( 30.85 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Stefan Eichenberger We are experiencing a problem with the i.MX I2C controller when communicating with SMBus devices. We are seeing devices time-out because the time between sending/receiving two bytes is too long, and the SMBus device returns to the idle state. This happens because the i.MX I2C controller sends and receives byte by byte. When a byte is sent or received, we get an interrupt and can send or receive the next byte. The current implementation sends a byte and then waits for an event generated by the interrupt subroutine. After the event is received, the next byte is sent and we wait again. This waiting allows the scheduler to reschedule other tasks, with the disadvantage that we may not send the next byte for a long time because the send task is not immediately scheduled. For example, if the rescheduling takes more than 25ms, this can cause SMBus devices to timeout and communication to fail. This patch changes the behavior so that we do not reschedule the send/receive task, but instead send or receive the next byte in the interrupt subroutine. This prevents rescheduling and drastically reduces the time between sending/receiving bytes. The cost in the interrupt subroutine is relatively small, we check what state we are in and then send/receive the next byte. Before we had to call wake_up, which is even less expensive. However, we also had to do some scheduling, which increased the overall cost compared to the new solution. The wake_up function to wake up the send/receive task is now only called when an error occurs or when the transfer is complete. Signed-off-by: Stefan Eichenberger Acked-by: Oleksij Rempel --- drivers/i2c/busses/i2c-imx.c | 257 ++++++++++++++++++++++++++++++++--- 1 file changed, 235 insertions(+), 22 deletions(-) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 9917f3e1d06cf..c2a92d1857af1 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -197,6 +197,17 @@ struct imx_i2c_dma { enum dma_data_direction dma_data_dir; }; +enum imx_i2c_state { + IMX_I2C_STATE_DONE, + IMX_I2C_STATE_FAILED, + IMX_I2C_STATE_WRITE, + IMX_I2C_STATE_DMA, + IMX_I2C_STATE_READ, + IMX_I2C_STATE_READ_CONTINUE, + IMX_I2C_STATE_READ_BLOCK_DATA, + IMX_I2C_STATE_READ_BLOCK_DATA_LEN, +}; + struct imx_i2c_struct { struct i2c_adapter adapter; struct clk *clk; @@ -216,6 +227,12 @@ struct imx_i2c_struct { struct i2c_client *slave; enum i2c_slave_event last_slave_event; + struct i2c_msg *msg; + unsigned int msg_buf_idx; + int isr_result; + bool is_lastmsg; + enum imx_i2c_state state; + bool multi_master; /* For checking slave events. */ @@ -908,11 +925,150 @@ static int i2c_imx_unreg_slave(struct i2c_client *client) return ret; } +static inline int i2c_imx_isr_acked(struct imx_i2c_struct *i2c_imx) +{ + i2c_imx->isr_result = 0; + + if (imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR) & I2SR_RXAK) { + i2c_imx->state = IMX_I2C_STATE_FAILED; + i2c_imx->isr_result = -ENXIO; + wake_up(&i2c_imx->queue); + } + + return i2c_imx->isr_result; +} + +static inline int i2c_imx_isr_write(struct imx_i2c_struct *i2c_imx) +{ + int result; + + result = i2c_imx_isr_acked(i2c_imx); + if (result) + return result; + + if (i2c_imx->msg->len == i2c_imx->msg_buf_idx) + return 0; + + imx_i2c_write_reg(i2c_imx->msg->buf[i2c_imx->msg_buf_idx++], i2c_imx, IMX_I2C_I2DR); + + return 1; +} + +static inline int i2c_imx_isr_read(struct imx_i2c_struct *i2c_imx) +{ + int result; + unsigned int temp; + + result = i2c_imx_isr_acked(i2c_imx); + if (result) + return result; + + /* setup bus to read data */ + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); + temp &= ~I2CR_MTX; + if (i2c_imx->msg->len - 1) + temp &= ~I2CR_TXAK; + + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); + imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); /* dummy read */ + + return 0; +} + +static inline void i2c_imx_isr_read_continue(struct imx_i2c_struct *i2c_imx) +{ + unsigned int temp; + + if ((i2c_imx->msg->len - 1) == i2c_imx->msg_buf_idx) { + if (i2c_imx->is_lastmsg) { + /* + * It must generate STOP before read I2DR to prevent + * controller from generating another clock cycle + */ + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); + if (!(temp & I2CR_MSTA)) + i2c_imx->stopped = 1; + temp &= ~(I2CR_MSTA | I2CR_MTX); + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); + } else { + /* + * For i2c master receiver repeat restart operation like: + * read -> repeat MSTA -> read/write + * The controller must set MTX before read the last byte in + * the first read operation, otherwise the first read cost + * one extra clock cycle. + */ + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); + temp |= I2CR_MTX; + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); + } + } else if (i2c_imx->msg_buf_idx == (i2c_imx->msg->len - 2)) { + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); + temp |= I2CR_TXAK; + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); + } + + i2c_imx->msg->buf[i2c_imx->msg_buf_idx++] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); +} + +static inline void i2c_imx_isr_read_block_data_len(struct imx_i2c_struct *i2c_imx) +{ + u8 len = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); + + if ((len == 0) || (len > I2C_SMBUS_BLOCK_MAX)) { + i2c_imx->isr_result = -EPROTO; + i2c_imx->state = IMX_I2C_STATE_FAILED; + wake_up(&i2c_imx->queue); + } + i2c_imx->msg->len += len; +} + static irqreturn_t i2c_imx_master_isr(struct imx_i2c_struct *i2c_imx, unsigned int status) { - /* save status register */ - i2c_imx->i2csr = status; - wake_up(&i2c_imx->queue); + switch (i2c_imx->state) { + case IMX_I2C_STATE_DMA: + i2c_imx->i2csr = status; + wake_up(&i2c_imx->queue); + break; + + case IMX_I2C_STATE_READ: + if (i2c_imx_isr_read(i2c_imx)) + break; + i2c_imx->state = IMX_I2C_STATE_READ_CONTINUE; + break; + + case IMX_I2C_STATE_READ_CONTINUE: + i2c_imx_isr_read_continue(i2c_imx); + if (i2c_imx->msg_buf_idx == i2c_imx->msg->len) { + i2c_imx->state = IMX_I2C_STATE_DONE; + wake_up(&i2c_imx->queue); + } + break; + + case IMX_I2C_STATE_READ_BLOCK_DATA: + if (i2c_imx_isr_read(i2c_imx)) + break; + i2c_imx->state = IMX_I2C_STATE_READ_BLOCK_DATA_LEN; + break; + + case IMX_I2C_STATE_READ_BLOCK_DATA_LEN: + i2c_imx_isr_read_block_data_len(i2c_imx); + i2c_imx->state = IMX_I2C_STATE_READ_CONTINUE; + break; + + case IMX_I2C_STATE_WRITE: + if (i2c_imx_isr_write(i2c_imx)) + break; + i2c_imx->state = IMX_I2C_STATE_DONE; + wake_up(&i2c_imx->queue); + break; + + default: + i2c_imx->i2csr = status; + i2c_imx->state = IMX_I2C_STATE_FAILED; + i2c_imx->isr_result = -EINVAL; + wake_up(&i2c_imx->queue); + } return IRQ_HANDLED; } @@ -959,6 +1115,8 @@ static int i2c_imx_dma_write(struct imx_i2c_struct *i2c_imx, struct imx_i2c_dma *dma = i2c_imx->dma; struct device *dev = &i2c_imx->adapter.dev; + i2c_imx->state = IMX_I2C_STATE_DMA; + dma->chan_using = dma->chan_tx; dma->dma_transfer_dir = DMA_MEM_TO_DEV; dma->dma_data_dir = DMA_TO_DEVICE; @@ -1012,15 +1170,14 @@ static int i2c_imx_dma_write(struct imx_i2c_struct *i2c_imx, } static int i2c_imx_prepare_read(struct imx_i2c_struct *i2c_imx, - struct i2c_msg *msgs, bool atomic, - bool use_dma) + struct i2c_msg *msgs, bool use_dma) { int result; unsigned int temp = 0; /* write slave address */ imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR); - result = i2c_imx_trx_complete(i2c_imx, atomic); + result = i2c_imx_trx_complete(i2c_imx, !use_dma); if (result) return result; result = i2c_imx_acked(i2c_imx); @@ -1058,7 +1215,9 @@ static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx, struct imx_i2c_dma *dma = i2c_imx->dma; struct device *dev = &i2c_imx->adapter.dev; - result = i2c_imx_prepare_read(i2c_imx, msgs, false, true); + i2c_imx->state = IMX_I2C_STATE_DMA; + + result = i2c_imx_prepare_read(i2c_imx, msgs, true); if (result) return result; @@ -1139,8 +1298,8 @@ static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx, return 0; } -static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, - bool atomic) +static int i2c_imx_atomic_write(struct imx_i2c_struct *i2c_imx, + struct i2c_msg *msgs) { int i, result; @@ -1149,7 +1308,7 @@ static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, /* write slave address */ imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR); - result = i2c_imx_trx_complete(i2c_imx, atomic); + result = i2c_imx_trx_complete(i2c_imx, true); if (result) return result; result = i2c_imx_acked(i2c_imx); @@ -1163,7 +1322,7 @@ static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, "<%s> write byte: B%d=0x%X\n", __func__, i, msgs->buf[i]); imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR); - result = i2c_imx_trx_complete(i2c_imx, atomic); + result = i2c_imx_trx_complete(i2c_imx, true); if (result) return result; result = i2c_imx_acked(i2c_imx); @@ -1173,19 +1332,40 @@ static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, return 0; } -static int i2c_imx_atomic_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs) +static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs) { - return i2c_imx_write(i2c_imx, msgs, true); + dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n", + __func__, i2c_8bit_addr_from_msg(msgs)); + + i2c_imx->state = IMX_I2C_STATE_WRITE; + i2c_imx->msg = msgs; + i2c_imx->msg_buf_idx = 0; + /* write slave address and start transmission */ + imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR); + wait_event_timeout(i2c_imx->queue, + i2c_imx->state == IMX_I2C_STATE_DONE || + i2c_imx->state == IMX_I2C_STATE_FAILED, + (msgs->len + 1)*HZ / 10); + if (i2c_imx->state == IMX_I2C_STATE_FAILED) { + dev_err(&i2c_imx->adapter.dev, "<%s> write failed with %d\n", + __func__, i2c_imx->isr_result); + return i2c_imx->isr_result; + } + if (i2c_imx->state != IMX_I2C_STATE_DONE) { + dev_err(&i2c_imx->adapter.dev, "<%s> write timedout\n", __func__); + return -ETIMEDOUT; + } + return 0; } -static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, - bool is_lastmsg, bool atomic) +static int i2c_imx_atomic_read(struct imx_i2c_struct *i2c_imx, + struct i2c_msg *msgs, bool is_lastmsg) { int i, result; unsigned int temp; int block_data = msgs->flags & I2C_M_RECV_LEN; - result = i2c_imx_prepare_read(i2c_imx, msgs, atomic, false); + result = i2c_imx_prepare_read(i2c_imx, msgs, false); if (result) return result; @@ -1195,7 +1375,7 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, for (i = 0; i < msgs->len; i++) { u8 len = 0; - result = i2c_imx_trx_complete(i2c_imx, atomic); + result = i2c_imx_trx_complete(i2c_imx, true); if (result) return result; /* @@ -1226,7 +1406,7 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, temp &= ~(I2CR_MSTA | I2CR_MTX); imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); if (!i2c_imx->stopped) - i2c_imx_bus_busy(i2c_imx, 0, atomic); + i2c_imx_bus_busy(i2c_imx, 0, true); } else { /* * For i2c master receiver repeat restart operation like: @@ -1257,10 +1437,43 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, return 0; } -static int i2c_imx_atomic_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, +static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bool is_lastmsg) { - return i2c_imx_read(i2c_imx, msgs, is_lastmsg, true); + int block_data = msgs->flags & I2C_M_RECV_LEN; + + dev_dbg(&i2c_imx->adapter.dev, + "<%s> write slave address: addr=0x%x\n", + __func__, i2c_8bit_addr_from_msg(msgs)); + + i2c_imx->is_lastmsg = is_lastmsg; + + if (block_data) + i2c_imx->state = IMX_I2C_STATE_READ_BLOCK_DATA; + else + i2c_imx->state = IMX_I2C_STATE_READ; + i2c_imx->msg = msgs; + i2c_imx->msg_buf_idx = 0; + + /* write slave address */ + imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR); + wait_event_timeout(i2c_imx->queue, + i2c_imx->state == IMX_I2C_STATE_DONE || + i2c_imx->state == IMX_I2C_STATE_FAILED, + (msgs->len + 1)*HZ / 10); + if (i2c_imx->state == IMX_I2C_STATE_FAILED) { + dev_err(&i2c_imx->adapter.dev, "<%s> write failed with %d\n", + __func__, i2c_imx->isr_result); + return i2c_imx->isr_result; + } + if (i2c_imx->state != IMX_I2C_STATE_DONE) { + dev_err(&i2c_imx->adapter.dev, "<%s> write timedout\n", __func__); + return -ETIMEDOUT; + } + if (!i2c_imx->stopped) + return i2c_imx_bus_busy(i2c_imx, 0, false); + + return 0; } static int i2c_imx_xfer_common(struct i2c_adapter *adapter, @@ -1334,14 +1547,14 @@ static int i2c_imx_xfer_common(struct i2c_adapter *adapter, else if (use_dma && !block_data) result = i2c_imx_dma_read(i2c_imx, &msgs[i], is_lastmsg); else - result = i2c_imx_read(i2c_imx, &msgs[i], is_lastmsg, false); + result = i2c_imx_read(i2c_imx, &msgs[i], is_lastmsg); } else { if (atomic) result = i2c_imx_atomic_write(i2c_imx, &msgs[i]); else if (use_dma) result = i2c_imx_dma_write(i2c_imx, &msgs[i]); else - result = i2c_imx_write(i2c_imx, &msgs[i], false); + result = i2c_imx_write(i2c_imx, &msgs[i]); } if (result) goto fail0;