From patchwork Fri Jul 6 06:09:15 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Marek Vasut X-Patchwork-Id: 169329 Return-Path: X-Original-To: incoming-imx@patchwork.ozlabs.org Delivered-To: patchwork-incoming-imx@bilbo.ozlabs.org Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:4978:20e::2]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 7F9282C0203 for ; Fri, 6 Jul 2012 16:19:14 +1000 (EST) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1Sn1ja-00026r-Sc; Fri, 06 Jul 2012 06:09:42 +0000 Received: from mail-out.m-online.net ([212.18.0.9]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1Sn1jJ-00026U-NG for linux-arm-kernel@lists.infradead.org; Fri, 06 Jul 2012 06:09:28 +0000 Received: from frontend4.mail.m-online.net (unknown [192.168.8.180]) by mail-out.m-online.net (Postfix) with ESMTP id 3WT5Bk5Trsz4KK93; Fri, 6 Jul 2012 08:10:06 +0200 (CEST) Received: from mashiro.lan (unknown [195.140.253.167]) by smtp-auth.mnet-online.de (Postfix) with ESMTPA id 3WT59r5g2czbcWb; Fri, 6 Jul 2012 08:09:19 +0200 (CEST) From: Marek Vasut To: linux-i2c@vger.kernel.org Subject: [PATCH 1/2 V2] MXS: Set I2C timing registers for mxs-i2c Date: Fri, 6 Jul 2012 08:09:15 +0200 Message-Id: <1341554956-17416-1-git-send-email-marex@denx.de> X-Mailer: git-send-email 1.7.10 MIME-Version: 1.0 X-Spam-Note: CRM114 invocation failed X-Spam-Score: -1.9 (-) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-1.9 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [212.18.0.9 listed in list.dnswl.org] -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Marek Vasut , Fabio Estevam , Wolfgang Denk , Detlev Zundel , Sascha Hauer , Wolfram Sang , Stefano Babic , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , Shawn Guo , Dong Aisheng , Linux ARM kernel X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+incoming-imx=patchwork.ozlabs.org@lists.infradead.org List-Id: linux-imx-kernel.lists.patchwork.ozlabs.org This patch configures the I2C bus timing registers according to information passed via DT. Currently, 100kHz and 400kHz modes are supported. The TIMING2 register value is wrong in the documentation for i.MX28! This was found and fixed by: Shawn Guo Signed-off-by: Marek Vasut Cc: Detlev Zundel CC: Dong Aisheng CC: Fabio Estevam Cc: Linux ARM kernel Cc: linux-i2c@vger.kernel.org CC: Sascha Hauer CC: Shawn Guo Cc: Stefano Babic CC: Uwe Kleine-König Cc: Wolfgang Denk Cc: Wolfram Sang --- Documentation/devicetree/bindings/i2c/i2c-mxs.txt | 2 + arch/arm/boot/dts/imx28.dtsi | 2 + drivers/i2c/busses/i2c-mxs.c | 56 +++++++++++++++++++++ 3 files changed, 60 insertions(+) V2: (even though technically V, I really need to start doing this patch management properly, it's quite a mess now) Fixed static const struct mxs_i2c_speed_config ... pointed by Dong. diff --git a/Documentation/devicetree/bindings/i2c/i2c-mxs.txt b/Documentation/devicetree/bindings/i2c/i2c-mxs.txt index 1bfc02d..2ed5332 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-mxs.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-mxs.txt @@ -4,6 +4,7 @@ Required properties: - compatible: Should be "fsl,-i2c" - reg: Should contain registers location and length - interrupts: Should contain ERROR and DMA interrupts +- clock-frequency: desired I2C bus clock frequency in Hz. Examples: @@ -13,4 +14,5 @@ i2c0: i2c@80058000 { compatible = "fsl,imx28-i2c"; reg = <0x80058000 2000>; interrupts = <111 68>; + clock-frequency = <400000>; }; diff --git a/arch/arm/boot/dts/imx28.dtsi b/arch/arm/boot/dts/imx28.dtsi index ee3778a..832d30a 100644 --- a/arch/arm/boot/dts/imx28.dtsi +++ b/arch/arm/boot/dts/imx28.dtsi @@ -419,6 +419,7 @@ compatible = "fsl,imx28-i2c"; reg = <0x80058000 2000>; interrupts = <111 68>; + clock-frequency = <400000>; status = "disabled"; }; @@ -428,6 +429,7 @@ compatible = "fsl,imx28-i2c"; reg = <0x8005a000 2000>; interrupts = <110 69>; + clock-frequency = <400000>; status = "disabled"; }; diff --git a/drivers/i2c/busses/i2c-mxs.c b/drivers/i2c/busses/i2c-mxs.c index 04eb441..47a7e20 100644 --- a/drivers/i2c/busses/i2c-mxs.c +++ b/drivers/i2c/busses/i2c-mxs.c @@ -46,6 +46,10 @@ #define MXS_I2C_CTRL0_DIRECTION 0x00010000 #define MXS_I2C_CTRL0_XFER_COUNT(v) ((v) & 0x0000FFFF) +#define MXS_I2C_TIMING0 (0x10) +#define MXS_I2C_TIMING1 (0x20) +#define MXS_I2C_TIMING2 (0x30) + #define MXS_I2C_CTRL1 (0x40) #define MXS_I2C_CTRL1_SET (0x44) #define MXS_I2C_CTRL1_CLR (0x48) @@ -97,6 +101,25 @@ #define MXS_CMD_I2C_READ (MXS_I2C_CTRL0_SEND_NAK_ON_LAST | \ MXS_I2C_CTRL0_MASTER_MODE) +struct mxs_i2c_speed_config { + uint32_t timing0; + uint32_t timing1; + uint32_t timing2; +}; + +/* Timing values for the default 24MHz clock supplied into the i2c block. */ +static const struct mxs_i2c_speed_config mxs_i2c_95kHz_config = { + .timing0 = 0x00780030, + .timing1 = 0x00800030, + .timing2 = 0x00300030, +}; + +static const struct mxs_i2c_speed_config mxs_i2c_400kHz_config = { + .timing0 = 0x000f0007, + .timing1 = 0x001f000f, + .timing2 = 0x00300030, +}; + /** * struct mxs_i2c_dev - per device, private MXS-I2C data * @@ -112,11 +135,17 @@ struct mxs_i2c_dev { struct completion cmd_complete; u32 cmd_err; struct i2c_adapter adapter; + const struct mxs_i2c_speed_config *speed; }; static void mxs_i2c_reset(struct mxs_i2c_dev *i2c) { stmp_reset_block(i2c->regs); + + writel(i2c->speed->timing0, i2c->regs + MXS_I2C_TIMING0); + writel(i2c->speed->timing1, i2c->regs + MXS_I2C_TIMING1); + writel(i2c->speed->timing2, i2c->regs + MXS_I2C_TIMING2); + writel(MXS_I2C_IRQ_MASK << 8, i2c->regs + MXS_I2C_CTRL1_SET); writel(MXS_I2C_QUEUECTRL_PIO_QUEUE_MODE, i2c->regs + MXS_I2C_QUEUECTRL_SET); @@ -319,6 +348,28 @@ static const struct i2c_algorithm mxs_i2c_algo = { .functionality = mxs_i2c_func, }; +static int mxs_i2c_get_ofdata(struct mxs_i2c_dev *i2c) +{ + uint32_t speed; + struct device *dev = i2c->dev; + struct device_node *node = dev->of_node; + int ret; + + if (!node) + return -EINVAL; + + i2c->speed = &mxs_i2c_95kHz_config; + ret = of_property_read_u32(node, "clock-frequency", &speed); + if (ret) + dev_warn(dev, "No I2C speed selected, using 100kHz\n"); + else if (speed == 400000) + i2c->speed = &mxs_i2c_400kHz_config; + else if (speed != 100000) + dev_warn(dev, "Invalid I2C speed selected, using 100kHz\n"); + + return 0; +} + static int __devinit mxs_i2c_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -358,6 +409,11 @@ static int __devinit mxs_i2c_probe(struct platform_device *pdev) return err; i2c->dev = dev; + + err = mxs_i2c_get_ofdata(i2c); + if (err) + return err; + platform_set_drvdata(pdev, i2c); /* Do reset to enforce correct startup after pinmuxing */