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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 54537C433E0 for ; Fri, 5 Feb 2021 21:23:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1C6A764FB9 for ; Fri, 5 Feb 2021 21:23:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232984AbhBEVXr (ORCPT ); Fri, 5 Feb 2021 16:23:47 -0500 Received: from mail.kernel.org ([198.145.29.99]:45588 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233044AbhBEPCP (ORCPT ); Fri, 5 Feb 2021 10:02:15 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id BB8F965040; Fri, 5 Feb 2021 14:11:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1612534313; bh=PDRrrhcxNK6kFhlHbZPEbR65Z68ghkWZSKmDzBTTGqI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=H+L7174IrcDp/LoOpxLXrvdaVRGVJueMkhmiuywBOR1mpW16OM4awov/rpByQ8IdO 06OGxan3BqG0cAhaJLJ0dKoHo3PkSibGdo+BLEqdiiSFgVhe+EMTEwLzDMA7rf5VP8 HwwzuiUI6RgmLTFhYwdYjNT2Zgq6aLKf+JV2eYgs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sowjanya Komatineni , Dmitry Osipenko , Thierry Reding , Wolfram Sang , Sasha Levin Subject: [PATCH 5.10 37/57] i2c: tegra: Create i2c_writesl_vi() to use with VI I2C for filling TX FIFO Date: Fri, 5 Feb 2021 15:07:03 +0100 Message-Id: <20210205140657.561912580@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210205140655.982616732@linuxfoundation.org> References: <20210205140655.982616732@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sowjanya Komatineni [ Upstream commit 2f3a0828d46166d4e7df227479ed31766ee67e4a ] VI I2C controller has known hardware bug where immediate multiple writes to TX_FIFO register gets stuck. Recommended software work around is to read I2C register after each write to TX_FIFO register to flush out the data. This patch implements this work around for VI I2C controller. Signed-off-by: Sowjanya Komatineni Reviewed-by: Dmitry Osipenko Acked-by: Thierry Reding Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin --- drivers/i2c/busses/i2c-tegra.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c index 0727383f49402..8b113ae32dc71 100644 --- a/drivers/i2c/busses/i2c-tegra.c +++ b/drivers/i2c/busses/i2c-tegra.c @@ -326,6 +326,8 @@ static void i2c_writel(struct tegra_i2c_dev *i2c_dev, u32 val, unsigned int reg) /* read back register to make sure that register writes completed */ if (reg != I2C_TX_FIFO) readl_relaxed(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg)); + else if (i2c_dev->is_vi) + readl_relaxed(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, I2C_INT_STATUS)); } static u32 i2c_readl(struct tegra_i2c_dev *i2c_dev, unsigned int reg) @@ -339,6 +341,21 @@ static void i2c_writesl(struct tegra_i2c_dev *i2c_dev, void *data, writesl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len); } +static void i2c_writesl_vi(struct tegra_i2c_dev *i2c_dev, void *data, + unsigned int reg, unsigned int len) +{ + u32 *data32 = data; + + /* + * VI I2C controller has known hardware bug where writes get stuck + * when immediate multiple writes happen to TX_FIFO register. + * Recommended software work around is to read I2C register after + * each write to TX_FIFO register to flush out the data. + */ + while (len--) + i2c_writel(i2c_dev, *data32++, reg); +} + static void i2c_readsl(struct tegra_i2c_dev *i2c_dev, void *data, unsigned int reg, unsigned int len) { @@ -811,7 +828,10 @@ static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev) i2c_dev->msg_buf_remaining = buf_remaining; i2c_dev->msg_buf = buf + words_to_transfer * BYTES_PER_FIFO_WORD; - i2c_writesl(i2c_dev, buf, I2C_TX_FIFO, words_to_transfer); + if (i2c_dev->is_vi) + i2c_writesl_vi(i2c_dev, buf, I2C_TX_FIFO, words_to_transfer); + else + i2c_writesl(i2c_dev, buf, I2C_TX_FIFO, words_to_transfer); buf += words_to_transfer * BYTES_PER_FIFO_WORD; } -- 2.27.0