From mboxrd@z Thu Jan 1 00:00:00 1970 From: Santosh Shilimkar Subject: Re: [PATCHV2 3/5] OMAP: I2C: Remove the reset in the init path Date: Thu, 21 Jul 2011 16:57:07 +0530 Message-ID: <4E280D0B.1040701@ti.com> References: <1311246554-22975-1-git-send-email-shubhrajyoti@ti.com> <1311246554-22975-4-git-send-email-shubhrajyoti@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1311246554-22975-4-git-send-email-shubhrajyoti-l0cyMroinI0@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Shubhrajyoti D Cc: linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, khilman-l0cyMroinI0@public.gmane.org, rnayak-l0cyMroinI0@public.gmane.org, balajitk-l0cyMroinI0@public.gmane.org List-Id: linux-i2c@vger.kernel.org On 7/21/2011 4:39 PM, Shubhrajyoti D wrote: > The reset in the driver at init is not needed > anymore as the hwmod framework takes care of > reseting it. > > Signed-off-by: Shubhrajyoti D > --- > drivers/i2c/busses/i2c-omap.c | 73 ++++++++++++---------------------------- > 1 files changed, 22 insertions(+), 51 deletions(-) Excellent cleanup. Some minor coments > > diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c > index 8f87a37..8dc54d5 100644 > --- a/drivers/i2c/busses/i2c-omap.c > +++ b/drivers/i2c/busses/i2c-omap.c > @@ -155,9 +155,6 @@ enum { > #define OMAP_I2C_SYSTEST_SDA_O (1<< 0) /* SDA line drive out */ > #endif > > -/* OCP_SYSSTATUS bit definitions */ > -#define SYSS_RESETDONE_MASK (1<< 0) > - > /* OCP_SYSCONFIG bit definitions */ > #define SYSC_CLOCKACTIVITY_MASK (0x3<< 8) > #define SYSC_SIDLEMODE_MASK (0x3<< 3) > @@ -182,6 +179,7 @@ struct omap_i2c_dev { > u32 latency; /* maximum mpu wkup latency */ > void (*set_mpu_wkup_lat)(struct device *dev, > long latency); > + int (*device_reset)(struct device *dev); > u32 speed; /* Speed of bus in Khz */ > u16 cmd_err; > u8 *buf; > @@ -332,7 +330,6 @@ static int omap_i2c_init(struct omap_i2c_dev *dev) > u16 psc = 0, scll = 0, sclh = 0, buf = 0; > u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0; > unsigned long fclk_rate = 12000000; > - unsigned long timeout; > unsigned long internal_clk = 0; > struct clk *fclk; > struct platform_device *pdev; > @@ -341,53 +338,16 @@ static int omap_i2c_init(struct omap_i2c_dev *dev) > pdev = to_platform_device(dev->dev); > pdata = pdev->dev.platform_data; > > - if (dev->rev>= OMAP_I2C_OMAP1_REV_2) { > - /* Disable I2C controller before soft reset */ > - omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, > - omap_i2c_read_reg(dev, OMAP_I2C_CON_REG)& > - ~(OMAP_I2C_CON_EN)); > - > - omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, SYSC_SOFTRESET_MASK); > - /* For some reason we need to set the EN bit before the > - * reset done bit gets set. */ > - timeout = jiffies + OMAP_I2C_TIMEOUT; > - omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN); > - while (!(omap_i2c_read_reg(dev, OMAP_I2C_SYSS_REG)& > - SYSS_RESETDONE_MASK)) { > - if (time_after(jiffies, timeout)) { > - dev_warn(dev->dev, "timeout waiting " > - "for controller reset\n"); > - return -ETIMEDOUT; > - } > - msleep(1); > - } > - > - /* SYSC register is cleared by the reset; rewrite it */ > - if (dev->rev == OMAP_I2C_REV_ON_2430) { > - > - omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, > - SYSC_AUTOIDLE_MASK); > - > - } else if (dev->rev>= OMAP_I2C_REV_ON_3430) { > - dev->syscstate = SYSC_AUTOIDLE_MASK; > - dev->syscstate |= SYSC_ENAWAKEUP_MASK; > - dev->syscstate |= (SYSC_IDLEMODE_SMART<< > - __ffs(SYSC_SIDLEMODE_MASK)); > - dev->syscstate |= (SYSC_CLOCKACTIVITY_FCLK<< > - __ffs(SYSC_CLOCKACTIVITY_MASK)); > - > - omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, > - dev->syscstate); > - /* > - * Enabling all wakup sources to stop I2C freezing on > - * WFI instruction. > - * REVISIT: Some wkup sources might not be needed. > - */ > - dev->westate = OMAP_I2C_WE_ALL; > - if (dev->rev< OMAP_I2C_REV_ON_3530_4430) > - omap_i2c_write_reg(dev, OMAP_I2C_WE_REG, > - dev->westate); > - } > + if (dev->rev>= OMAP_I2C_REV_ON_3430) { Space please if (dev->rev >= OMAP_I2C_REV_ON_3430) { > + /* > + * Enabling all wakup sources to stop I2C freezing on > + * WFI instruction. > + * REVISIT: Some wkup sources might not be needed. > + */ Surely not related to your patch. But the 'REVISIT:' caught my attention. Is the comment still valid. > + dev->westate = OMAP_I2C_WE_ALL; > + if (dev->rev< OMAP_I2C_REV_ON_3530_4430) Space if (dev->rev < OMAP_I2C_REV_ON_3530_4430) > + omap_i2c_write_reg(dev, OMAP_I2C_WE_REG, > + dev->westate); > } > omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0); > > @@ -612,6 +572,11 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap, > return r; > if (r == 0) { > dev_err(dev->dev, "controller timed out\n"); > + if (dev->device_reset != NULL) { > + r = dev->device_reset(dev->dev); > + if (r< 0) ditto > + dev_err(dev->dev, "reset failed\n"); > + } > omap_i2c_init(dev); > return -ETIMEDOUT; > } > @@ -622,6 +587,11 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap, > /* We have an error */ > if (dev->cmd_err& (OMAP_I2C_STAT_AL | OMAP_I2C_STAT_ROVR | You can fix this one as well. > OMAP_I2C_STAT_XUDF)) { > + if (dev->device_reset != NULL) { > + r = dev->device_reset(dev->dev); > + if (r< 0) here too. > + dev_err(dev->dev, "reset failed\n"); > + } > omap_i2c_init(dev); > return -EIO; > } > @@ -1024,6 +994,7 @@ omap_i2c_probe(struct platform_device *pdev) > if (pdata != NULL) { > speed = pdata->clkrate; > dev->set_mpu_wkup_lat = pdata->set_mpu_wkup_lat; > + dev->device_reset = pdata->device_reset; > } else { > speed = 100; /* Default speed */ > dev->set_mpu_wkup_lat = NULL; Regards Santosh