From patchwork Tue Dec 8 10:13:36 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: chaithrika@ti.com X-Patchwork-Id: 65669 Received: from comal.ext.ti.com (comal.ext.ti.com [198.47.26.152]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id nB8AYJF7004754 for ; Tue, 8 Dec 2009 10:34:20 GMT Received: from dlep36.itg.ti.com ([157.170.170.91]) by comal.ext.ti.com (8.13.7/8.13.7) with ESMTP id nB8AWgw4026924 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 8 Dec 2009 04:32:42 -0600 Received: from linux.omap.com (localhost [127.0.0.1]) by dlep36.itg.ti.com (8.13.8/8.13.8) with ESMTP id nB8AWf0B006341; Tue, 8 Dec 2009 04:32:41 -0600 (CST) Received: from linux.omap.com (localhost [127.0.0.1]) by linux.omap.com (Postfix) with ESMTP id 2A22580630; Tue, 8 Dec 2009 04:32:40 -0600 (CST) X-Original-To: davinci-linux-open-source@linux.davincidsp.com Delivered-To: davinci-linux-open-source@linux.davincidsp.com Received: from dflp53.itg.ti.com (dflp53.itg.ti.com [128.247.5.6]) by linux.omap.com (Postfix) with ESMTP id 3290680626 for ; Tue, 8 Dec 2009 04:32:34 -0600 (CST) Received: from tidmzi-ftp.india.ext.ti.com (localhost [127.0.0.1]) by dflp53.itg.ti.com (8.13.8/8.13.8) with SMTP id nB8AWVXc029489; Tue, 8 Dec 2009 04:32:32 -0600 (CST) Received: from symphonyindia.ti.com (symphony-ftp [192.168.247.11]) by tidmzi-ftp.india.ext.ti.com (Postfix) with SMTP id B07FE38873; Tue, 8 Dec 2009 15:59:18 +0530 (IST) Received: from localhost.localdomain ([192.168.247.76]) by symphonyindia.ti.com (8.13.1/8.12.10) with ESMTP id nB8ANrwG011329; Tue, 8 Dec 2009 15:53:53 +0530 From: Chaithrika U S To: linux-i2c@vger.kernel.org Subject: [PATCH v2 2/4] i2c: davinci: Add helper functions Date: Tue, 8 Dec 2009 15:43:36 +0530 Message-Id: <1260267218-19406-3-git-send-email-chaithrika@ti.com> X-Mailer: git-send-email 1.5.6 In-Reply-To: <1260267218-19406-2-git-send-email-chaithrika@ti.com> References: <1260267218-19406-1-git-send-email-chaithrika@ti.com> <1260267218-19406-2-git-send-email-chaithrika@ti.com> Cc: davinci-linux-open-source@linux.davincidsp.com X-BeenThere: davinci-linux-open-source@linux.davincidsp.com X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: davinci-linux-open-source-bounces@linux.davincidsp.com Errors-To: davinci-linux-open-source-bounces@linux.davincidsp.com diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c index 44a3cb3..81c1049 100644 --- a/drivers/i2c/busses/i2c-davinci.c +++ b/drivers/i2c/busses/i2c-davinci.c @@ -124,12 +124,21 @@ static inline u16 davinci_i2c_read_reg(struct davinci_i2c_dev *i2c_dev, int reg) return __raw_readw(i2c_dev->base + reg); } -/* - * This functions configures I2C and brings I2C out of reset. - * This function is called during I2C init function. This function - * also gets called if I2C encounters any errors. - */ -static int i2c_davinci_init(struct davinci_i2c_dev *dev) +static inline void davinci_i2c_reset_ctrl(struct davinci_i2c_dev *i2c_dev, + int val) +{ + u16 w; + + w = davinci_i2c_read_reg(i2c_dev, DAVINCI_I2C_MDR_REG); + if (!val) /* put I2C into reset */ + w &= ~DAVINCI_I2C_MDR_IRS; + else /* take I2C out of reset */ + w |= DAVINCI_I2C_MDR_IRS; + + davinci_i2c_write_reg(i2c_dev, DAVINCI_I2C_MDR_REG, w); +} + +static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev) { struct davinci_i2c_platform_data *pdata = dev->dev->platform_data; u16 psc; @@ -138,15 +147,6 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev) u32 clkh; u32 clkl; u32 input_clock = clk_get_rate(dev->clk); - u16 w; - - if (!pdata) - pdata = &davinci_i2c_platform_data_default; - - /* put I2C into reset */ - w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); - w &= ~DAVINCI_I2C_MDR_IRS; - davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w); /* NOTE: I2C Clock divider programming info * As per I2C specs the following formulas provide prescaler @@ -178,12 +178,32 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev) davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKH_REG, clkh); davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKL_REG, clkl); + dev_dbg(dev->dev, "input_clock = %d, CLK = %d\n", input_clock, clk); +} + +/* + * This function configures I2C and brings I2C out of reset. + * This function is called during I2C init function. This function + * also gets called if I2C encounters any errors. + */ +static int i2c_davinci_init(struct davinci_i2c_dev *dev) +{ + struct davinci_i2c_platform_data *pdata = dev->dev->platform_data; + + if (!pdata) + pdata = &davinci_i2c_platform_data_default; + + /* put I2C into reset */ + davinci_i2c_reset_ctrl(dev, 0); + + /* compute clock dividers */ + i2c_davinci_calc_clk_dividers(dev); + /* Respond at reserved "SMBus Host" slave address" (and zero); * we seem to have no option to not respond... */ davinci_i2c_write_reg(dev, DAVINCI_I2C_OAR_REG, 0x08); - dev_dbg(dev->dev, "input_clock = %d, CLK = %d\n", input_clock, clk); dev_dbg(dev->dev, "PSC = %d\n", davinci_i2c_read_reg(dev, DAVINCI_I2C_PSC_REG)); dev_dbg(dev->dev, "CLKL = %d\n", @@ -194,9 +214,7 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev) pdata->bus_freq, pdata->bus_delay); /* Take the I2C module out of reset: */ - w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); - w |= DAVINCI_I2C_MDR_IRS; - davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w); + davinci_i2c_reset_ctrl(dev, 1); /* Enable interrupts */ davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, I2C_DAVINCI_INTR_ALL);