From patchwork Tue Jan 12 08:43:50 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sricharan Ramabadhran X-Patchwork-Id: 8015211 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id CA13FBEEE5 for ; Tue, 12 Jan 2016 08:46:24 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id D69D1203A1 for ; Tue, 12 Jan 2016 08:46:23 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E47C6203A5 for ; Tue, 12 Jan 2016 08:46:22 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1aIuZX-0003jz-Hi; Tue, 12 Jan 2016 08:44:59 +0000 Received: from smtp.codeaurora.org ([198.145.29.96]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1aIuZB-0003TB-BJ for linux-arm-kernel@lists.infradead.org; Tue, 12 Jan 2016 08:44:40 +0000 Received: from smtp.codeaurora.org (localhost [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id B22D360618; Tue, 12 Jan 2016 08:44:21 +0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1000) id A5E4460619; Tue, 12 Jan 2016 08:44:21 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from blr-ubuntu-32.ap.qualcomm.com (unknown [202.46.23.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: sricharan@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id B3E7160578; Tue, 12 Jan 2016 08:44:16 +0000 (UTC) From: Sricharan R To: devicetree@vger.kernel.org, linux-arm-msm@vger.kernel.org, agross@codeaurora.org, linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org, iivanov@mm-sol.com, galak@codeaurora.org, dmaengine@vger.kernel.org, linux-arm-kernel@lists.infradead.org, andy.gross@linaro.org, ntelkar@codeaurora.org, wsa@the-dreams.de Subject: [PATCH V6 3/6] i2c: qup: Transfer each i2c_msg in i2c_msgs without a stop bit Date: Tue, 12 Jan 2016 14:13:50 +0530 Message-Id: <1452588233-1803-4-git-send-email-sricharan@codeaurora.org> X-Mailer: git-send-email 1.8.2.1 In-Reply-To: <1452588233-1803-1-git-send-email-sricharan@codeaurora.org> References: <1452588233-1803-1-git-send-email-sricharan@codeaurora.org> X-Virus-Scanned: ClamAV using ClamSMTP X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160112_004437_827611_BAD34EE5 X-CRM114-Status: GOOD ( 22.98 ) X-Spam-Score: -1.9 (-) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: srichara@codeaurora.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP The definition of i2c_msg says that "If this is the last message in a group, it is followed by a STOP. Otherwise it is followed by the next @i2c_msg transaction segment, beginning with a (repeated) START" So the expectation is that there is no 'STOP' bit inbetween individual i2c_msg segments with repeated 'START'. The QUP i2c hardware has no way to inform that there should not be a 'STOP' at the end of transaction. The only way to implement this is to coalesce all the i2c_msg in i2c_msgs in to one transaction and transfer them. Adding the support for the same. This is required for some clients like touchscreen which keeps incrementing counts across individual transfers and 'STOP' bit inbetween resets the counter, which is not required. This patch adds the support in non-dma mode. Signed-off-by: Sricharan R Reviewed-by: Andy Gross --- drivers/i2c/busses/i2c-qup.c | 34 ++++++++++++++++++++++++++-------- 1 file changed, 26 insertions(+), 8 deletions(-) diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c index 715d4d7..f9009d6 100644 --- a/drivers/i2c/busses/i2c-qup.c +++ b/drivers/i2c/busses/i2c-qup.c @@ -112,6 +112,7 @@ #define SET_BIT 0x1 #define RESET_BIT 0x0 #define ONE_BYTE 0x1 +#define QUP_I2C_MX_CONFIG_DURING_RUN BIT(31) struct qup_i2c_block { int count; @@ -147,6 +148,12 @@ struct qup_i2c_dev { /* QUP core errors */ u32 qup_err; + /* To check if this is the last msg */ + bool is_last; + + /* To configure when bus is in run state */ + int config_run; + struct completion xfer; }; @@ -269,7 +276,7 @@ static int qup_i2c_wait_ready(struct qup_i2c_dev *qup, int op, bool val, status = readl(qup->base + QUP_I2C_STATUS); if (((opflags & op) >> shift) == val) { - if (op == QUP_OUT_NOT_EMPTY) { + if ((op == QUP_OUT_NOT_EMPTY) && qup->is_last) { if (!(status & I2C_STATUS_BUS_ACTIVE)) return 0; } else { @@ -290,6 +297,8 @@ static void qup_i2c_set_write_mode_v2(struct qup_i2c_dev *qup, /* Number of entries to shift out, including the tags */ int total = msg->len + qup->blk.tx_tag_len; + total |= qup->config_run; + if (total < qup->out_fifo_sz) { /* FIFO mode */ writel(QUP_REPACK_EN, qup->base + QUP_IO_MODE); @@ -443,7 +452,7 @@ static int qup_i2c_set_tags(u8 *tags, struct qup_i2c_dev *qup, } /* Send _STOP commands for the last block */ - if (qup->blk.pos == (qup->blk.count - 1)) { + if ((qup->blk.pos == (qup->blk.count - 1)) && qup->is_last) { if (msg->flags & I2C_M_RD) tags[len++] = QUP_TAG_V2_DATARD_STOP; else @@ -581,7 +590,6 @@ static int qup_i2c_write_one(struct qup_i2c_dev *qup, struct i2c_msg *msg) /* Wait for the outstanding data in the fifo to drain */ ret = qup_i2c_wait_ready(qup, QUP_OUT_NOT_EMPTY, RESET_BIT, ONE_BYTE); - err: disable_irq(qup->irq); qup->msg = NULL; @@ -608,18 +616,20 @@ static void qup_i2c_set_read_mode_v2(struct qup_i2c_dev *qup, int len) int tx_len = qup->blk.tx_tag_len; len += qup->blk.rx_tag_len; + len |= qup->config_run; + tx_len |= qup->config_run; if (len < qup->in_fifo_sz) { /* FIFO mode */ writel(QUP_REPACK_EN, qup->base + QUP_IO_MODE); - writel(len, qup->base + QUP_MX_READ_CNT); writel(tx_len, qup->base + QUP_MX_WRITE_CNT); + writel(len, qup->base + QUP_MX_READ_CNT); } else { /* BLOCK mode (transfer data on chunks) */ writel(QUP_INPUT_BLK_MODE | QUP_REPACK_EN, qup->base + QUP_IO_MODE); - writel(len, qup->base + QUP_MX_INPUT_CNT); writel(tx_len, qup->base + QUP_MX_OUTPUT_CNT); + writel(len, qup->base + QUP_MX_INPUT_CNT); } } @@ -866,6 +876,12 @@ static int qup_i2c_xfer_v2(struct i2c_adapter *adap, goto out; } + qup->is_last = (idx == (num - 1)); + if (idx) + qup->config_run = QUP_I2C_MX_CONFIG_DURING_RUN; + else + qup->config_run = 0; + reinit_completion(&qup->xfer); if (msgs[idx].flags & I2C_M_RD) @@ -873,13 +889,13 @@ static int qup_i2c_xfer_v2(struct i2c_adapter *adap, else ret = qup_i2c_write_one_v2(qup, &msgs[idx]); - if (!ret) - ret = qup_i2c_change_state(qup, QUP_RESET_STATE); - if (ret) break; } + if (!ret) + ret = qup_i2c_change_state(qup, QUP_RESET_STATE); + if (ret == 0) ret = num; out: @@ -1057,6 +1073,8 @@ static int qup_i2c_probe(struct platform_device *pdev) i2c_set_adapdata(&qup->adap, qup); qup->adap.dev.parent = qup->dev; qup->adap.dev.of_node = pdev->dev.of_node; + qup->is_last = 1; + strlcpy(qup->adap.name, "QUP I2C adapter", sizeof(qup->adap.name)); pm_runtime_set_autosuspend_delay(qup->dev, MSEC_PER_SEC);