From patchwork Tue Aug 24 03:30:22 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kewei Xu X-Patchwork-Id: 501996 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, UNPARSEABLE_RELAY, URIBL_BLOCKED, 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 4EF08C4338F for ; Tue, 24 Aug 2021 03:30:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 328EB6120C for ; Tue, 24 Aug 2021 03:30:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234127AbhHXDbX (ORCPT ); Mon, 23 Aug 2021 23:31:23 -0400 Received: from mailgw01.mediatek.com ([60.244.123.138]:37358 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S232937AbhHXDbV (ORCPT ); Mon, 23 Aug 2021 23:31:21 -0400 X-UUID: 8172cf42474c42fe8bebc8b1067c9c42-20210824 X-UUID: 8172cf42474c42fe8bebc8b1067c9c42-20210824 Received: from mtkcas07.mediatek.inc [(172.21.101.84)] by mailgw01.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 1591536162; Tue, 24 Aug 2021 11:30:34 +0800 Received: from MTKCAS06.mediatek.inc (172.21.101.30) by mtkmbs07n2.mediatek.inc (172.21.101.141) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 24 Aug 2021 11:30:32 +0800 Received: from localhost.localdomain (10.17.3.153) by MTKCAS06.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Tue, 24 Aug 2021 11:30:32 +0800 From: Kewei Xu To: CC: , , , , , , , , , , , , , , Subject: [RESEND PATCH v5 1/7] i2c: mediatek: fixing the incorrect register offset Date: Tue, 24 Aug 2021 11:30:22 +0800 Message-ID: <1629775828-19993-2-git-send-email-kewei.xu@mediatek.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1629775828-19993-1-git-send-email-kewei.xu@mediatek.com> References: <1629775828-19993-1-git-send-email-kewei.xu@mediatek.com> MIME-Version: 1.0 X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org The reason for the modification here is that the previous offset information is incorrect, OFFSET_DEBUGSTAT = 0xE4 is the correct value. Fixes: 25708278f810 ("i2c: mediatek: Add i2c support for MediaTek MT8183") Signed-off-by: Kewei Xu Reviewed-by: Chen-Yu Tsai --- drivers/i2c/busses/i2c-mt65xx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c index 4ca716e..2661ed0 100644 --- a/drivers/i2c/busses/i2c-mt65xx.c +++ b/drivers/i2c/busses/i2c-mt65xx.c @@ -193,7 +193,7 @@ enum I2C_REGS_OFFSET { [OFFSET_CLOCK_DIV] = 0x48, [OFFSET_SOFTRESET] = 0x50, [OFFSET_SCL_MIS_COMP_POINT] = 0x90, - [OFFSET_DEBUGSTAT] = 0xe0, + [OFFSET_DEBUGSTAT] = 0xe4, [OFFSET_DEBUGCTRL] = 0xe8, [OFFSET_FIFO_STAT] = 0xf4, [OFFSET_FIFO_THRESH] = 0xf8, From patchwork Tue Aug 24 03:30:23 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kewei Xu X-Patchwork-Id: 502544 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, UNPARSEABLE_RELAY, 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 E9401C4320A for ; Tue, 24 Aug 2021 03:30:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CB14F6120C for ; Tue, 24 Aug 2021 03:30:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234202AbhHXDbX (ORCPT ); Mon, 23 Aug 2021 23:31:23 -0400 Received: from mailgw02.mediatek.com ([210.61.82.184]:56084 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S233836AbhHXDbV (ORCPT ); Mon, 23 Aug 2021 23:31:21 -0400 X-UUID: 554b264281de49dfa053e439ccf25e91-20210824 X-UUID: 554b264281de49dfa053e439ccf25e91-20210824 Received: from mtkcas10.mediatek.inc [(172.21.101.39)] by mailgw02.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 923366344; Tue, 24 Aug 2021 11:30:35 +0800 Received: from MTKCAS06.mediatek.inc (172.21.101.30) by mtkmbs07n2.mediatek.inc (172.21.101.141) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 24 Aug 2021 11:30:33 +0800 Received: from localhost.localdomain (10.17.3.153) by MTKCAS06.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Tue, 24 Aug 2021 11:30:33 +0800 From: Kewei Xu To: CC: , , , , , , , , , , , , , , Subject: [RESEND PATCH v5 2/7] i2c: mediatek: Reset the handshake signal between i2c and dma Date: Tue, 24 Aug 2021 11:30:23 +0800 Message-ID: <1629775828-19993-3-git-send-email-kewei.xu@mediatek.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1629775828-19993-1-git-send-email-kewei.xu@mediatek.com> References: <1629775828-19993-1-git-send-email-kewei.xu@mediatek.com> MIME-Version: 1.0 X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Due to changes in the hardware design of the handshaking signal between i2c and dma, it is necessary to reset the handshaking signal before each transfer to ensure that the multi-msgs can be transferred correctly. Signed-off-by: Kewei Xu --- drivers/i2c/busses/i2c-mt65xx.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c index 2661ed0..abda525 100644 --- a/drivers/i2c/busses/i2c-mt65xx.c +++ b/drivers/i2c/busses/i2c-mt65xx.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -47,6 +48,9 @@ #define I2C_RD_TRANAC_VALUE 0x0001 #define I2C_SCL_MIS_COMP_VALUE 0x0000 #define I2C_CHN_CLR_FLAG 0x0000 +#define I2C_CLR_DEBUGCTR 0x0000 +#define I2C_RELIABILITY 0x0010 +#define I2C_DMAACK_ENABLE 0x0008 #define I2C_DMA_CON_TX 0x0000 #define I2C_DMA_CON_RX 0x0001 @@ -842,6 +846,7 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs, u16 restart_flag = 0; u16 dma_sync = 0; u32 reg_4g_mode; + u32 reg_dma_reset; u8 *dma_rd_buf = NULL; u8 *dma_wr_buf = NULL; dma_addr_t rpaddr = 0; @@ -855,6 +860,27 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs, reinit_completion(&i2c->msg_complete); + if (i2c->dev_comp->apdma_sync && left_num > 1) { + mtk_i2c_writew(i2c, I2C_CLR_DEBUGCTR, OFFSET_DEBUGCTRL); + writel(I2C_DMA_HANDSHAKE_RST | I2C_DMA_WARM_RST, + i2c->pdmabase + OFFSET_RST); + + ret = readw_poll_timeout(i2c->pdmabase + OFFSET_RST, + reg_dma_reset, + !(reg_dma_reset & I2C_DMA_WARM_RST), + 0, 100); + if (ret) { + dev_err(i2c->dev, "DMA warm reset timeout\n"); + return -ETIMEDOUT; + } + + writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST); + mtk_i2c_writew(i2c, I2C_HANDSHAKE_RST, OFFSET_SOFTRESET); + mtk_i2c_writew(i2c, I2C_CHN_CLR_FLAG, OFFSET_SOFTRESET); + mtk_i2c_writew(i2c, I2C_RELIABILITY | I2C_DMAACK_ENABLE, + OFFSET_DEBUGCTRL); + } + control_reg = mtk_i2c_readw(i2c, OFFSET_CONTROL) & ~(I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS); if ((i2c->speed_hz > I2C_MAX_FAST_MODE_PLUS_FREQ) || (left_num >= 1)) From patchwork Tue Aug 24 03:30:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kewei Xu X-Patchwork-Id: 501995 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, UNPARSEABLE_RELAY, URIBL_BLOCKED, 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 6650CC43216 for ; Tue, 24 Aug 2021 03:30:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4F9FE6124B for ; Tue, 24 Aug 2021 03:30:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234298AbhHXDbZ (ORCPT ); Mon, 23 Aug 2021 23:31:25 -0400 Received: from mailgw01.mediatek.com ([60.244.123.138]:37484 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S234148AbhHXDbY (ORCPT ); Mon, 23 Aug 2021 23:31:24 -0400 X-UUID: 7310251c52404d90b5b836ed717e95c3-20210824 X-UUID: 7310251c52404d90b5b836ed717e95c3-20210824 Received: from mtkexhb01.mediatek.inc [(172.21.101.102)] by mailgw01.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 546788706; Tue, 24 Aug 2021 11:30:36 +0800 Received: from MTKCAS06.mediatek.inc (172.21.101.30) by mtkmbs07n1.mediatek.inc (172.21.101.16) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 24 Aug 2021 11:30:34 +0800 Received: from localhost.localdomain (10.17.3.153) by MTKCAS06.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Tue, 24 Aug 2021 11:30:34 +0800 From: Kewei Xu To: CC: , , , , , , , , , , , , , , Subject: [RESEND PATCH v5 3/7] i2c: mediatek: Dump i2c/dma register when a timeout occurs Date: Tue, 24 Aug 2021 11:30:24 +0800 Message-ID: <1629775828-19993-4-git-send-email-kewei.xu@mediatek.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1629775828-19993-1-git-send-email-kewei.xu@mediatek.com> References: <1629775828-19993-1-git-send-email-kewei.xu@mediatek.com> MIME-Version: 1.0 X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org When a timeout error occurs in i2c transter, it is usually related to the i2c/dma IP hardware configuration. Therefore, the purpose of this patch is to dump the key register values of i2c/dma when a timeout occurs in i2c for debugging. Signed-off-by: Kewei Xu --- drivers/i2c/busses/i2c-mt65xx.c | 56 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 55 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c index abda525..633bce4 100644 --- a/drivers/i2c/busses/i2c-mt65xx.c +++ b/drivers/i2c/busses/i2c-mt65xx.c @@ -129,6 +129,7 @@ enum I2C_REGS_OFFSET { OFFSET_HS, OFFSET_SOFTRESET, OFFSET_DCM_EN, + OFFSET_MULTI_DMA, OFFSET_PATH_DIR, OFFSET_DEBUGSTAT, OFFSET_DEBUGCTRL, @@ -196,6 +197,7 @@ enum I2C_REGS_OFFSET { [OFFSET_TRANSFER_LEN_AUX] = 0x44, [OFFSET_CLOCK_DIV] = 0x48, [OFFSET_SOFTRESET] = 0x50, + [OFFSET_MULTI_DMA] = 0x8c, [OFFSET_SCL_MIS_COMP_POINT] = 0x90, [OFFSET_DEBUGSTAT] = 0xe4, [OFFSET_DEBUGCTRL] = 0xe8, @@ -837,6 +839,57 @@ static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk) return 0; } +static void i2c_dump_register(struct mtk_i2c *i2c) +{ + dev_err(i2c->dev, "SLAVE_ADDR: 0x%x, INTR_MASK: 0x%x\n", + mtk_i2c_readw(i2c, OFFSET_SLAVE_ADDR), + mtk_i2c_readw(i2c, OFFSET_INTR_MASK)); + dev_err(i2c->dev, "INTR_STAT: 0x%x, CONTROL: 0x%x\n", + mtk_i2c_readw(i2c, OFFSET_INTR_STAT), + mtk_i2c_readw(i2c, OFFSET_CONTROL)); + dev_err(i2c->dev, "TRANSFER_LEN: 0x%x, TRANSAC_LEN: 0x%x\n", + mtk_i2c_readw(i2c, OFFSET_TRANSFER_LEN), + mtk_i2c_readw(i2c, OFFSET_TRANSAC_LEN)); + dev_err(i2c->dev, "DELAY_LEN: 0x%x, HTIMING: 0x%x\n", + mtk_i2c_readw(i2c, OFFSET_DELAY_LEN), + mtk_i2c_readw(i2c, OFFSET_TIMING)); + dev_err(i2c->dev, "START: 0x%x, EXT_CONF: 0x%x\n", + mtk_i2c_readw(i2c, OFFSET_START), + mtk_i2c_readw(i2c, OFFSET_EXT_CONF)); + dev_err(i2c->dev, "HS: 0x%x, IO_CONFIG: 0x%x\n", + mtk_i2c_readw(i2c, OFFSET_HS), + mtk_i2c_readw(i2c, OFFSET_IO_CONFIG)); + dev_err(i2c->dev, "DCM_EN: 0x%x, TRANSFER_LEN_AUX: 0x%x\n", + mtk_i2c_readw(i2c, OFFSET_DCM_EN), + mtk_i2c_readw(i2c, OFFSET_TRANSFER_LEN_AUX)); + dev_err(i2c->dev, "CLOCK_DIV: 0x%x, FIFO_STAT: 0x%x\n", + mtk_i2c_readw(i2c, OFFSET_CLOCK_DIV), + mtk_i2c_readw(i2c, OFFSET_FIFO_STAT)); + dev_err(i2c->dev, "DEBUGCTRL : 0x%x, DEBUGSTAT: 0x%x\n", + mtk_i2c_readw(i2c, OFFSET_DEBUGCTRL), + mtk_i2c_readw(i2c, OFFSET_DEBUGSTAT)); + if (i2c->dev_comp->regs == mt_i2c_regs_v2) { + dev_err(i2c->dev, "LTIMING: 0x%x, MULTI_DMA: 0x%x\n", + mtk_i2c_readw(i2c, OFFSET_LTIMING), + mtk_i2c_readw(i2c, OFFSET_MULTI_DMA)); + } + dev_err(i2c->dev, "\nDMA_INT_FLAG: 0x%x, DMA_INT_EN: 0x%x\n", + readl(i2c->pdmabase + OFFSET_INT_FLAG), + readl(i2c->pdmabase + OFFSET_INT_EN)); + dev_err(i2c->dev, "DMA_EN: 0x%x, DMA_CON: 0x%x\n", + readl(i2c->pdmabase + OFFSET_EN), + readl(i2c->pdmabase + OFFSET_CON)); + dev_err(i2c->dev, "DMA_TX_MEM_ADDR: 0x%x, DMA_RX_MEM_ADDR: 0x%x\n", + readl(i2c->pdmabase + OFFSET_TX_MEM_ADDR), + readl(i2c->pdmabase + OFFSET_RX_MEM_ADDR)); + dev_err(i2c->dev, "DMA_TX_LEN: 0x%x, DMA_RX_LEN: 0x%x\n", + readl(i2c->pdmabase + OFFSET_TX_LEN), + readl(i2c->pdmabase + OFFSET_RX_LEN)); + dev_err(i2c->dev, "DMA_TX_4G_MODE: 0x%x, DMA_RX_4G_MODE: 0x%x", + readl(i2c->pdmabase + OFFSET_TX_4G_MODE), + readl(i2c->pdmabase + OFFSET_RX_4G_MODE)); +} + static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs, int num, int left_num) { @@ -1065,7 +1118,8 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs, } if (ret == 0) { - dev_dbg(i2c->dev, "addr: %x, transfer timeout\n", msgs->addr); + dev_err(i2c->dev, "addr: %x, transfer timeout\n", msgs->addr); + i2c_dump_register(i2c); mtk_i2c_init_hw(i2c); return -ETIMEDOUT; } From patchwork Tue Aug 24 03:30:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kewei Xu X-Patchwork-Id: 501993 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, UNPARSEABLE_RELAY, 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 31CDFC4320A for ; Tue, 24 Aug 2021 03:30:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B59C6120A for ; Tue, 24 Aug 2021 03:30:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234581AbhHXDbd (ORCPT ); Mon, 23 Aug 2021 23:31:33 -0400 Received: from mailgw01.mediatek.com ([60.244.123.138]:37504 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S232605AbhHXDbY (ORCPT ); Mon, 23 Aug 2021 23:31:24 -0400 X-UUID: 286aa35c5766491a9aa61877174c0299-20210824 X-UUID: 286aa35c5766491a9aa61877174c0299-20210824 Received: from mtkcas10.mediatek.inc [(172.21.101.39)] by mailgw01.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 1610211224; Tue, 24 Aug 2021 11:30:37 +0800 Received: from MTKCAS06.mediatek.inc (172.21.101.30) by mtkmbs07n2.mediatek.inc (172.21.101.141) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 24 Aug 2021 11:30:35 +0800 Received: from localhost.localdomain (10.17.3.153) by MTKCAS06.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Tue, 24 Aug 2021 11:30:35 +0800 From: Kewei Xu To: CC: , , , , , , , , , , , , , , Subject: [RESEND PATCH v5 4/7] dt-bindings: i2c: add attribute use-default-timing Date: Tue, 24 Aug 2021 11:30:25 +0800 Message-ID: <1629775828-19993-5-git-send-email-kewei.xu@mediatek.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1629775828-19993-1-git-send-email-kewei.xu@mediatek.com> References: <1629775828-19993-1-git-send-email-kewei.xu@mediatek.com> MIME-Version: 1.0 X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Add attribute use-default-timing for DT-binding document. Fixes: be5ce0e97cc7 ("i2c: mediatek: Add i2c ac-timing adjust support") Signed-off-by: Kewei Xu Acked-by: Rob Herring --- Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt | 2 ++ 1 file changed, 2 insertions(+) diff --git a/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt b/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt index 5ea216a..4dbb697 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt @@ -34,6 +34,8 @@ Optional properties: Only mt6589 and mt8135 support this feature. - mediatek,use-push-pull: IO config use push-pull mode. - vbus-supply: phandle to the regulator that provides power to SCL/SDA. + - mediatek,use-default-timing: use default timing calculation, no timing + adjustment. Example: From patchwork Tue Aug 24 03:30:26 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kewei Xu X-Patchwork-Id: 502543 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, UNPARSEABLE_RELAY, URIBL_BLOCKED, 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 A1D3BC4338F for ; Tue, 24 Aug 2021 03:30:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 824636120A for ; Tue, 24 Aug 2021 03:30:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234377AbhHXDb1 (ORCPT ); Mon, 23 Aug 2021 23:31:27 -0400 Received: from mailgw02.mediatek.com ([210.61.82.184]:56260 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S234249AbhHXDbZ (ORCPT ); Mon, 23 Aug 2021 23:31:25 -0400 X-UUID: 5bdbe7efc79c4316a554f5c047b42b06-20210824 X-UUID: 5bdbe7efc79c4316a554f5c047b42b06-20210824 Received: from mtkexhb02.mediatek.inc [(172.21.101.103)] by mailgw02.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 619583467; Tue, 24 Aug 2021 11:30:38 +0800 Received: from MTKCAS06.mediatek.inc (172.21.101.30) by mtkmbs07n1.mediatek.inc (172.21.101.16) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 24 Aug 2021 11:30:37 +0800 Received: from localhost.localdomain (10.17.3.153) by MTKCAS06.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Tue, 24 Aug 2021 11:30:36 +0800 From: Kewei Xu To: CC: , , , , , , , , , , , , , , Subject: [RESEND PATCH v5 5/7] i2c: mediatek: Add OFFSET_EXT_CONF setting back Date: Tue, 24 Aug 2021 11:30:26 +0800 Message-ID: <1629775828-19993-6-git-send-email-kewei.xu@mediatek.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1629775828-19993-1-git-send-email-kewei.xu@mediatek.com> References: <1629775828-19993-1-git-send-email-kewei.xu@mediatek.com> MIME-Version: 1.0 X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org In the commit be5ce0e97cc7 ("i2c: mediatek: Add i2c ac-timing adjust support"), we miss setting OFFSET_EXT_CONF register if i2c->dev_comp->timing_adjust is false, now add it back. Fixes: be5ce0e97cc7 ("i2c: mediatek: Add i2c ac-timing adjust support") Signed-off-by: Kewei Xu --- drivers/i2c/busses/i2c-mt65xx.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c index 633bce4..4da6b43 100644 --- a/drivers/i2c/busses/i2c-mt65xx.c +++ b/drivers/i2c/busses/i2c-mt65xx.c @@ -42,6 +42,8 @@ #define I2C_HANDSHAKE_RST 0x0020 #define I2C_FIFO_ADDR_CLR 0x0001 #define I2C_DELAY_LEN 0x0002 +#define I2C_ST_START_CON 0x8001 +#define I2C_FS_START_CON 0x1800 #define I2C_TIME_CLR_VALUE 0x0000 #define I2C_TIME_DEFAULT_VALUE 0x0003 #define I2C_WRRD_TRANAC_VALUE 0x0002 @@ -486,6 +488,7 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c) { u16 control_reg; u16 intr_stat_reg; + u16 ext_conf_val; mtk_i2c_writew(i2c, I2C_CHN_CLR_FLAG, OFFSET_START); intr_stat_reg = mtk_i2c_readw(i2c, OFFSET_INTR_STAT); @@ -524,8 +527,13 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c) if (i2c->dev_comp->ltiming_adjust) mtk_i2c_writew(i2c, i2c->ltiming_reg, OFFSET_LTIMING); + if (i2c->speed_hz <= I2C_MAX_STANDARD_MODE_FREQ) + ext_conf_val = I2C_ST_START_CON; + else + ext_conf_val = I2C_FS_START_CON; + if (i2c->dev_comp->timing_adjust) { - mtk_i2c_writew(i2c, i2c->ac_timing.ext, OFFSET_EXT_CONF); + ext_conf_val = i2c->ac_timing.ext; mtk_i2c_writew(i2c, i2c->ac_timing.inter_clk_div, OFFSET_CLOCK_DIV); mtk_i2c_writew(i2c, I2C_SCL_MIS_COMP_VALUE, @@ -550,6 +558,7 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c) OFFSET_HS_STA_STO_AC_TIMING); } } + mtk_i2c_writew(i2c, ext_conf_val, OFFSET_EXT_CONF); /* If use i2c pin from PMIC mt6397 side, need set PATH_DIR first */ if (i2c->have_pmic) From patchwork Tue Aug 24 03:30:27 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kewei Xu X-Patchwork-Id: 501994 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, UNPARSEABLE_RELAY, URIBL_BLOCKED, 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 18FD8C41537 for ; Tue, 24 Aug 2021 03:30:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 003A26120A for ; Tue, 24 Aug 2021 03:30:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234474AbhHXDba (ORCPT ); Mon, 23 Aug 2021 23:31:30 -0400 Received: from mailgw02.mediatek.com ([210.61.82.184]:56290 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S234284AbhHXDb0 (ORCPT ); Mon, 23 Aug 2021 23:31:26 -0400 X-UUID: 6aad7f8bc87844e9ac9416b9f47f5ab0-20210824 X-UUID: 6aad7f8bc87844e9ac9416b9f47f5ab0-20210824 Received: from mtkcas11.mediatek.inc [(172.21.101.40)] by mailgw02.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 85510752; Tue, 24 Aug 2021 11:30:39 +0800 Received: from MTKCAS06.mediatek.inc (172.21.101.30) by mtkmbs07n2.mediatek.inc (172.21.101.141) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 24 Aug 2021 11:30:38 +0800 Received: from localhost.localdomain (10.17.3.153) by MTKCAS06.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Tue, 24 Aug 2021 11:30:37 +0800 From: Kewei Xu To: CC: , , , , , , , , , , , , , , Subject: [RESEND PATCH v5 6/7] i2c: mediatek: Isolate speed setting via dts for special devices Date: Tue, 24 Aug 2021 11:30:27 +0800 Message-ID: <1629775828-19993-7-git-send-email-kewei.xu@mediatek.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1629775828-19993-1-git-send-email-kewei.xu@mediatek.com> References: <1629775828-19993-1-git-send-email-kewei.xu@mediatek.com> MIME-Version: 1.0 X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org In the commit be5ce0e97cc7 ("i2c: mediatek: Add i2c ac-timing adjust support"), the I2C timing calculation has been revised to support ac-timing adjustment, however that will break on some I2C components. As a result we want to introduce a new setting "default-adjust-timing" so those components can choose to use the old (default) timing algorithm. Fixes: be5ce0e97cc7 ("i2c: mediatek: Add i2c ac-timing adjust support") Signed-off-by: Kewei Xu --- drivers/i2c/busses/i2c-mt65xx.c | 77 ++++++++++++++++++++++++++++++++++++++--- 1 file changed, 73 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c index 4da6b43..18b5659 100644 --- a/drivers/i2c/busses/i2c-mt65xx.c +++ b/drivers/i2c/busses/i2c-mt65xx.c @@ -66,6 +66,7 @@ #define I2C_DMA_HARD_RST 0x0002 #define I2C_DMA_HANDSHAKE_RST 0x0004 +#define I2C_DEFAULT_CLK_DIV 5 #define MAX_SAMPLE_CNT_DIV 8 #define MAX_STEP_CNT_DIV 64 #define MAX_CLOCK_DIV 256 @@ -250,6 +251,7 @@ struct mtk_i2c { struct clk *clk_arb; /* Arbitrator clock for i2c */ bool have_pmic; /* can use i2c pins from PMIC */ bool use_push_pull; /* IO config push-pull mode */ + bool use_default_timing; /* no timing adjust mode */ u16 irq_stat; /* interrupt status */ unsigned int clk_src_div; @@ -532,7 +534,11 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c) else ext_conf_val = I2C_FS_START_CON; - if (i2c->dev_comp->timing_adjust) { + if (i2c->use_default_timing) { + if (i2c->dev_comp->timing_adjust) + mtk_i2c_writew(i2c, I2C_DEFAULT_CLK_DIV - 1, + OFFSET_CLOCK_DIV); + } else if (i2c->dev_comp->timing_adjust) { ext_conf_val = i2c->ac_timing.ext; mtk_i2c_writew(i2c, i2c->ac_timing.inter_clk_div, OFFSET_CLOCK_DIV); @@ -615,7 +621,7 @@ static int mtk_i2c_check_ac_timing(struct mtk_i2c *i2c, unsigned int sample_ns = div_u64(1000000000ULL * (sample_cnt + 1), clk_src); - if (!i2c->dev_comp->timing_adjust) + if (i2c->use_default_timing || !i2c->dev_comp->timing_adjust) return 0; if (i2c->dev_comp->ltiming_adjust) @@ -775,7 +781,65 @@ static int mtk_i2c_calculate_speed(struct mtk_i2c *i2c, unsigned int clk_src, return 0; } -static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk) +static int mtk_i2c_set_speed_default_timing(struct mtk_i2c *i2c, + unsigned int parent_clk) +{ + unsigned int clk_src; + unsigned int step_cnt; + unsigned int sample_cnt; + unsigned int l_step_cnt; + unsigned int l_sample_cnt; + unsigned int target_speed; + int ret; + + if (i2c->dev_comp->timing_adjust) + i2c->clk_src_div *= I2C_DEFAULT_CLK_DIV; + + clk_src = parent_clk / i2c->clk_src_div; + target_speed = i2c->speed_hz; + + if (target_speed > I2C_MAX_FAST_MODE_PLUS_FREQ) { + /* Set master code speed register */ + ret = mtk_i2c_calculate_speed(i2c, clk_src, + I2C_MAX_FAST_MODE_FREQ, + &l_step_cnt, &l_sample_cnt); + if (ret < 0) + return ret; + + i2c->timing_reg = (l_sample_cnt << 8) | l_step_cnt; + + /* Set the high speed mode register */ + ret = mtk_i2c_calculate_speed(i2c, clk_src, target_speed, + &step_cnt, &sample_cnt); + if (ret < 0) + return ret; + + i2c->high_speed_reg = I2C_TIME_DEFAULT_VALUE | + (sample_cnt << 12) | (step_cnt << 8); + + if (i2c->dev_comp->ltiming_adjust) + i2c->ltiming_reg = (l_sample_cnt << 6) | l_step_cnt | + (sample_cnt << 12) | (step_cnt << 9); + } else { + ret = mtk_i2c_calculate_speed(i2c, clk_src, target_speed, + &step_cnt, &sample_cnt); + if (ret < 0) + return ret; + + i2c->timing_reg = (sample_cnt << 8) | step_cnt; + + /* Disable the high speed transaction */ + i2c->high_speed_reg = I2C_TIME_CLR_VALUE; + + if (i2c->dev_comp->ltiming_adjust) + i2c->ltiming_reg = (sample_cnt << 6) | step_cnt; + } + + return 0; +} + +static int mtk_i2c_set_speed_adjust_timing(struct mtk_i2c *i2c, + unsigned int parent_clk) { unsigned int clk_src; unsigned int step_cnt; @@ -1271,6 +1335,8 @@ static int mtk_i2c_parse_dt(struct device_node *np, struct mtk_i2c *i2c) i2c->have_pmic = of_property_read_bool(np, "mediatek,have-pmic"); i2c->use_push_pull = of_property_read_bool(np, "mediatek,use-push-pull"); + i2c->use_default_timing = + of_property_read_bool(np, "mediatek,use-default-timing"); i2c_parse_fw_timings(i2c->dev, &i2c->timing_info, true); @@ -1357,7 +1423,10 @@ static int mtk_i2c_probe(struct platform_device *pdev) strlcpy(i2c->adap.name, I2C_DRV_NAME, sizeof(i2c->adap.name)); - ret = mtk_i2c_set_speed(i2c, clk_get_rate(clk)); + if (i2c->use_default_timing) + ret = mtk_i2c_set_speed_default_timing(i2c, clk_get_rate(clk)); + else + ret = mtk_i2c_set_speed_adjust_timing(i2c, clk_get_rate(clk)); if (ret) { dev_err(&pdev->dev, "Failed to set the speed.\n"); return -EINVAL; From patchwork Tue Aug 24 03:30:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kewei Xu X-Patchwork-Id: 502542 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, UNPARSEABLE_RELAY, URIBL_BLOCKED, 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 71925C4320E for ; Tue, 24 Aug 2021 03:30:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5CCA561185 for ; Tue, 24 Aug 2021 03:30:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234422AbhHXDb3 (ORCPT ); Mon, 23 Aug 2021 23:31:29 -0400 Received: from mailgw01.mediatek.com ([60.244.123.138]:37570 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S232937AbhHXDb1 (ORCPT ); Mon, 23 Aug 2021 23:31:27 -0400 X-UUID: e13adde845df445da4c0281484c3e099-20210824 X-UUID: e13adde845df445da4c0281484c3e099-20210824 Received: from mtkcas06.mediatek.inc [(172.21.101.30)] by mailgw01.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 708686720; Tue, 24 Aug 2021 11:30:40 +0800 Received: from MTKCAS06.mediatek.inc (172.21.101.30) by mtkmbs07n1.mediatek.inc (172.21.101.16) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 24 Aug 2021 11:30:39 +0800 Received: from localhost.localdomain (10.17.3.153) by MTKCAS06.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Tue, 24 Aug 2021 11:30:38 +0800 From: Kewei Xu To: CC: , , , , , , , , , , , , , , Subject: [RESEND PATCH v5 7/7] i2c: mediatek: modify bus speed calculation formula Date: Tue, 24 Aug 2021 11:30:28 +0800 Message-ID: <1629775828-19993-8-git-send-email-kewei.xu@mediatek.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1629775828-19993-1-git-send-email-kewei.xu@mediatek.com> References: <1629775828-19993-1-git-send-email-kewei.xu@mediatek.com> MIME-Version: 1.0 X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org When clock-div is 0 or greater than 1, the bus speed calculated by the old speed calculation formula will be larger than the target speed. So we update the formula. Signed-off-by: Kewei Xu --- drivers/i2c/busses/i2c-mt65xx.c | 35 +++++++++++++++++++++++++---------- 1 file changed, 25 insertions(+), 10 deletions(-) diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c index 18b5659..0b42acd8 100644 --- a/drivers/i2c/busses/i2c-mt65xx.c +++ b/drivers/i2c/busses/i2c-mt65xx.c @@ -69,11 +69,12 @@ #define I2C_DEFAULT_CLK_DIV 5 #define MAX_SAMPLE_CNT_DIV 8 #define MAX_STEP_CNT_DIV 64 -#define MAX_CLOCK_DIV 256 +#define MAX_CLOCK_DIV_8BITS 256 +#define MAX_CLOCK_DIV_5BITS 32 #define MAX_HS_STEP_CNT_DIV 8 -#define I2C_STANDARD_MODE_BUFFER (1000 / 2) -#define I2C_FAST_MODE_BUFFER (300 / 2) -#define I2C_FAST_MODE_PLUS_BUFFER (20 / 2) +#define I2C_STANDARD_MODE_BUFFER (1000 / 3) +#define I2C_FAST_MODE_BUFFER (300 / 3) +#define I2C_FAST_MODE_PLUS_BUFFER (20 / 3) #define I2C_CONTROL_RS (0x1 << 1) #define I2C_CONTROL_DMA_EN (0x1 << 2) @@ -725,14 +726,26 @@ static int mtk_i2c_calculate_speed(struct mtk_i2c *i2c, unsigned int clk_src, unsigned int best_mul; unsigned int cnt_mul; int ret = -EINVAL; + int clock_div_constraint = 0; if (target_speed > I2C_MAX_HIGH_SPEED_MODE_FREQ) target_speed = I2C_MAX_HIGH_SPEED_MODE_FREQ; + if (i2c->use_default_timing) { + clock_div_constraint = 0; + } else if (i2c->dev_comp->ltiming_adjust && + i2c->ac_timing.inter_clk_div > 1) { + clock_div_constraint = 1; + } else if (i2c->dev_comp->ltiming_adjust && + i2c->ac_timing.inter_clk_div == 0) { + clock_div_constraint = -1; + } + max_step_cnt = mtk_i2c_max_step_cnt(target_speed); base_step_cnt = max_step_cnt; /* Find the best combination */ - opt_div = DIV_ROUND_UP(clk_src >> 1, target_speed); + opt_div = DIV_ROUND_UP(clk_src >> 1, target_speed) + + clock_div_constraint; best_mul = MAX_SAMPLE_CNT_DIV * max_step_cnt; /* Search for the best pair (sample_cnt, step_cnt) with @@ -767,7 +780,8 @@ static int mtk_i2c_calculate_speed(struct mtk_i2c *i2c, unsigned int clk_src, sample_cnt = base_sample_cnt; step_cnt = base_step_cnt; - if ((clk_src / (2 * sample_cnt * step_cnt)) > target_speed) { + if ((clk_src / (2 * (sample_cnt * step_cnt - clock_div_constraint))) > + target_speed) { /* In this case, hardware can't support such * low i2c_bus_freq */ @@ -854,13 +868,16 @@ static int mtk_i2c_set_speed_adjust_timing(struct mtk_i2c *i2c, target_speed = i2c->speed_hz; parent_clk /= i2c->clk_src_div; - if (i2c->dev_comp->timing_adjust) - max_clk_div = MAX_CLOCK_DIV; + if (i2c->dev_comp->timing_adjust && i2c->dev_comp->ltiming_adjust) + max_clk_div = MAX_CLOCK_DIV_5BITS; + else if (i2c->dev_comp->timing_adjust) + max_clk_div = MAX_CLOCK_DIV_8BITS; else max_clk_div = 1; for (clk_div = 1; clk_div <= max_clk_div; clk_div++) { clk_src = parent_clk / clk_div; + i2c->ac_timing.inter_clk_div = clk_div - 1; if (target_speed > I2C_MAX_FAST_MODE_PLUS_FREQ) { /* Set master code speed register */ @@ -907,8 +924,6 @@ static int mtk_i2c_set_speed_adjust_timing(struct mtk_i2c *i2c, break; } - i2c->ac_timing.inter_clk_div = clk_div - 1; - return 0; }