From patchwork Tue Jan 26 23:41:30 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Hilman X-Patchwork-Id: 75294 Received: from devils.ext.ti.com (devils.ext.ti.com [198.47.26.153]) by demeter.kernel.org (8.14.3/8.14.2) with ESMTP id o0QNn6Rt011762 for ; Tue, 26 Jan 2010 23:49:07 GMT Received: from dlep36.itg.ti.com ([157.170.170.91]) by devils.ext.ti.com (8.13.7/8.13.7) with ESMTP id o0QNgZmN022266 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 26 Jan 2010 17:42:35 -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 o0QNgZnn020697; Tue, 26 Jan 2010 17:42:35 -0600 (CST) Received: from linux.omap.com (localhost [127.0.0.1]) by linux.omap.com (Postfix) with ESMTP id 9577B8064A; Tue, 26 Jan 2010 17:42:26 -0600 (CST) X-Original-To: davinci-linux-open-source@linux.davincidsp.com Delivered-To: davinci-linux-open-source@linux.davincidsp.com Received: from dflp51.itg.ti.com (dflp51.itg.ti.com [128.247.22.94]) by linux.omap.com (Postfix) with ESMTP id 6F52980637 for ; Tue, 26 Jan 2010 17:41:43 -0600 (CST) Received: from neches.ext.ti.com (localhost [127.0.0.1]) by dflp51.itg.ti.com (8.13.7/8.13.7) with ESMTP id o0QNfht8024363 for ; Tue, 26 Jan 2010 17:41:43 -0600 (CST) Received: from psmtp.com (na3sys009amx238.postini.com [74.125.149.122]) by neches.ext.ti.com (8.13.7/8.13.7) with SMTP id o0QNfgei003363 for ; Tue, 26 Jan 2010 17:41:42 -0600 Received: from source ([209.85.216.189]) by na3sys009amx238.postini.com ([74.125.148.10]) with SMTP; Tue, 26 Jan 2010 18:41:42 EST Received: by mail-px0-f189.google.com with SMTP id 27so3462536pxi.4 for ; Tue, 26 Jan 2010 15:41:42 -0800 (PST) Received: by 10.142.59.19 with SMTP id h19mr5942152wfa.243.1264549302389; Tue, 26 Jan 2010 15:41:42 -0800 (PST) Received: from localhost (deeprootsystems.com [216.254.16.51]) by mx.google.com with ESMTPS id 23sm6165943pzk.12.2010.01.26.15.41.41 (version=TLSv1/SSLv3 cipher=RC4-MD5); Tue, 26 Jan 2010 15:41:41 -0800 (PST) From: Kevin Hilman To: Ben Dooks Subject: [PATCH 3/6] i2c: davinci: Add helper functions Date: Tue, 26 Jan 2010 15:41:30 -0800 Message-Id: <1264549293-25556-4-git-send-email-khilman@deeprootsystems.com> X-Mailer: git-send-email 1.6.6 In-Reply-To: <1264549293-25556-1-git-send-email-khilman@deeprootsystems.com> References: <1264549293-25556-1-git-send-email-khilman@deeprootsystems.com> X-pstn-neptune: 0/0/0.00/0 X-pstn-levels: (S:99.90000/99.90000 CV:99.9000 FC:95.5390 LC:95.5390 R:95.9108 P:95.9108 M:97.0282 C:98.6951 ) X-pstn-settings: 2 (0.5000:0.5000) s cv gt3 gt2 gt1 X-pstn-addresses: from [db-null] Cc: davinci-linux-open-source@linux.davincidsp.com, linux-i2c@vger.kernel.org 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 34a48d0..aacef7b 100644 --- a/drivers/i2c/busses/i2c-davinci.c +++ b/drivers/i2c/busses/i2c-davinci.c @@ -125,12 +125,21 @@ 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; @@ -139,15 +148,6 @@ 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 @@ -179,12 +179,32 @@ 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", @@ -195,9 +215,7 @@ 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);