Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755810Ab3EaO7i (ORCPT ); Fri, 31 May 2013 10:59:38 -0400 Received: from comal.ext.ti.com ([198.47.26.152]:44618 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756079Ab3EaO7Z (ORCPT ); Fri, 31 May 2013 10:59:25 -0400 Message-ID: <51A8B9EA.6030604@ti.com> Date: Fri, 31 May 2013 17:55:38 +0300 From: Grygorii Strashko User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130510 Thunderbird/17.0.6 MIME-Version: 1.0 To: Hebbar Gururaja CC: , , , , , , , , , , , Tony Lindgren , Wolfram Sang , , Subject: Re: [PATCH 11/11] i2c: omap: enhance pinctrl support References: <1369995191-20855-1-git-send-email-gururaja.hebbar@ti.com> <1369995191-20855-12-git-send-email-gururaja.hebbar@ti.com> In-Reply-To: <1369995191-20855-12-git-send-email-gururaja.hebbar@ti.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8879 Lines: 247 On 05/31/2013 01:13 PM, Hebbar Gururaja wrote: > Amend the I2C omap pin controller to optionally take a pin control > handle and set the state of the pins to: > > - "default" on boot, resume and before performing an i2c transfer > - "idle" after initial default, after resume default, and after each > i2c xfer > - "sleep" on suspend() > > By optionally putting the pins into sleep state in the suspend callback > we can accomplish two things. > - One is to minimize current leakage from pins and thus save power, > - second, we can prevent the IP from driving pins output in an > uncontrolled manner, which may happen if the power domain drops the > domain regulator. > > Note: > A .suspend & .resume callback is added which simply puts the pins to sleep > state upon suspend & are moved to default & idle state upon resume. > > If any of the above pin states are missing in dt, a warning message > about the missing state is displayed. > If certain pin-states are not available, to remove this warning message > pass respective state name with null phandler. > > (Changes based on i2c-nomadik.c) > > Signed-off-by: Hebbar Gururaja > Cc: Tony Lindgren > Cc: Wolfram Sang > Cc: linux-omap@vger.kernel.org > Cc: linux-i2c@vger.kernel.org > --- > :100644 100644 e02f9e3... 588ba28... M drivers/i2c/busses/i2c-omap.c > drivers/i2c/busses/i2c-omap.c | 112 ++++++++++++++++++++++++++++++++++++++--- > 1 file changed, 105 insertions(+), 7 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c > index e02f9e3..588ba28 100644 > --- a/drivers/i2c/busses/i2c-omap.c > +++ b/drivers/i2c/busses/i2c-omap.c > @@ -214,7 +214,11 @@ struct omap_i2c_dev { > u16 westate; > u16 errata; > > - struct pinctrl *pins; > + /* Three pin states - default, idle & sleep */ > + struct pinctrl *pinctrl; > + struct pinctrl_state *pins_default; > + struct pinctrl_state *pins_idle; > + struct pinctrl_state *pins_sleep; > }; > > static const u8 reg_map_ip_v1[] = { > @@ -641,6 +645,11 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) > if (IS_ERR_VALUE(r)) > goto out; > The current HWMOD framework configures PINs to enable state before enabling the device and switch PINs to idle state after disabling the device. Why here its done in different order? > + /* Optionaly enable pins to be muxed in and configured */ > + if (!IS_ERR(dev->pins_default)) > + if (pinctrl_select_state(dev->pinctrl, dev->pins_default)) > + dev_err(dev->dev, "could not set default pins\n"); > + > r = omap_i2c_wait_for_bb(dev); > if (r < 0) > goto out; > @@ -664,7 +673,13 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) > > out: > pm_runtime_mark_last_busy(dev->dev); > + > pm_runtime_put_autosuspend(dev->dev); > + /* Optionally let pins go into idle state */ > + if (!IS_ERR(dev->pins_idle)) > + if (pinctrl_select_state(dev->pinctrl, dev->pins_idle)) > + dev_err(dev->dev, "could not set pins to idle state\n"); > + > return r; > } > > @@ -1123,14 +1138,47 @@ omap_i2c_probe(struct platform_device *pdev) > dev->set_mpu_wkup_lat = pdata->set_mpu_wkup_lat; > } > > - dev->pins = devm_pinctrl_get_select_default(&pdev->dev); > - if (IS_ERR(dev->pins)) { > - if (PTR_ERR(dev->pins) == -EPROBE_DEFER) > + dev->pinctrl = devm_pinctrl_get(&pdev->dev); May be struct device ->pins->p can be used instead of dev->pinctrl? > + if (!IS_ERR(dev->pinctrl)) { > + dev->pins_default = pinctrl_lookup_state(dev->pinctrl, > + PINCTRL_STATE_DEFAULT); > + if (IS_ERR(dev->pins_default)) > + dev_dbg(&pdev->dev, "could not get default pinstate\n"); > + else > + if (pinctrl_select_state(dev->pinctrl, > + dev->pins_default)) > + dev_err(&pdev->dev, > + "could not set default pinstate\n"); Don't need to set Default pin state Default pins state is applied by DD framework automatically before device probing and stored in struct device ->pins->default_state > + > + dev->pins_idle = pinctrl_lookup_state(dev->pinctrl, > + PINCTRL_STATE_IDLE); > + if (IS_ERR(dev->pins_idle)) > + dev_dbg(&pdev->dev, "could not get idle pinstate\n"); > + else > + /* If possible, let's idle until the first transfer */ > + if (pinctrl_select_state(dev->pinctrl, dev->pins_idle)) > + dev_err(&pdev->dev, > + "could not set idle pinstate\n"); > + > + dev->pins_sleep = pinctrl_lookup_state(dev->pinctrl, > + PINCTRL_STATE_SLEEP); > + if (IS_ERR(dev->pins_sleep)) > + dev_dbg(&pdev->dev, "could not get sleep pinstate\n"); > + } else { > + if (PTR_ERR(dev->pinctrl) == -EPROBE_DEFER) > return -EPROBE_DEFER; > > - dev_warn(&pdev->dev, "did not get pins for i2c error: %li\n", > - PTR_ERR(dev->pins)); > - dev->pins = NULL; > + /* > + * Since we continue even when pinctrl node is not found, > + * Invalidate pins as not available. This is to make sure that > + * IS_ERR(pins_xxx) results in failure when used. > + */ > + dev->pins_default = ERR_PTR(-ENODATA); > + dev->pins_idle = ERR_PTR(-ENODATA); > + dev->pins_sleep = ERR_PTR(-ENODATA); > + > + dev_dbg(&pdev->dev, "did not get pins for i2c error: %li\n", > + PTR_ERR(dev->pinctrl)); > } > > dev->dev = &pdev->dev; > @@ -1300,6 +1348,10 @@ static int omap_i2c_runtime_suspend(struct device *dev) > omap_i2c_read_reg(_dev, OMAP_I2C_STAT_REG); > } > > + if (!IS_ERR(_dev->pins_idle)) > + if (pinctrl_select_state(_dev->pinctrl, _dev->pins_idle)) > + dev_err(dev, "could not set pins to idle state\n"); > + It's done in omap_i2c_xfer > return 0; > } > > @@ -1311,13 +1363,59 @@ static int omap_i2c_runtime_resume(struct device *dev) > if (!_dev->regs) > return 0; > > + /* Optionally place the pins to the default state */ > + if (!IS_ERR(_dev->pins_default)) > + if (pinctrl_select_state(_dev->pinctrl, _dev->pins_default)) > + dev_err(dev, "could not set pins to default state\n"); > + It's done in omap_i2c_xfer > __omap_i2c_init(_dev); > > return 0; > } > #endif /* CONFIG_PM_RUNTIME */ > > +#ifdef CONFIG_PM_SLEEP > +static int omap_i2c_suspend(struct device *dev) Please, use .suspend_noirq() - it's possible that I2C will be used even after "device suspend" stage especially on SMP platforms((( ), but its prohibited to use it after "suspend_noirq" stage ( > +{ > + struct platform_device *pdev = to_platform_device(dev); > + struct omap_i2c_dev *_dev = platform_get_drvdata(pdev); > + > + pm_runtime_get_sync(dev); Here is the better way to detect late I2C activities during suspending: i2c_lock_adapter(&_dev->adapter); /* Check for active I2C transaction */ if (atomic_read(&dev->power.usage_count) > 1) { dev_info(dev, "active I2C transaction detected - suspend aborted\n"); return -EBUSY; } i2c_unlock_adapter(&_dev->adapter); > + if (omap_i2c_wait_for_bb(_dev) < 0) { > + pm_runtime_put_sync(dev); > + return -EBUSY; > + } > + pm_runtime_put_sync(dev); > + > + if (!IS_ERR(_dev->pins_sleep)) > + if (pinctrl_select_state(_dev->pinctrl, _dev->pins_sleep)) > + dev_err(dev, "could not set pins to sleep state\n"); > + > + return 0; > +} Not sure it's right - Lest assume suspend_noirq() is used here. Then, at this point, OMAP device framework will disable device (_od_suspend_noirq()). But PINs will be switched to IDLE state before that. Is it ok? Possibly Kevin could clarify this point? > + > +static int omap_i2c_resume(struct device *dev) Please, use .resume_noirq() > +{ The same is here - OMAP device framework will enable device (_od_suspend_noirq()) here. But PINs are still in IDLE state??? > + struct platform_device *pdev = to_platform_device(dev); > + struct omap_i2c_dev *_dev = platform_get_drvdata(pdev); > + > + /* First go to the default state */ > + if (!IS_ERR(_dev->pins_default)) > + if (pinctrl_select_state(_dev->pinctrl, _dev->pins_default)) > + dev_err(dev, "could not set pins to default state\n"); > + > + /* Then let's idle the pins until the next transfer happens */ > + if (!IS_ERR(_dev->pins_idle)) > + if (pinctrl_select_state(_dev->pinctrl, _dev->pins_idle)) > + dev_err(dev, "could not set pins to idle state\n"); > + This is wrong - at this moment I2C device can be as in Enabled state as in Disabled > + return 0; > +} > +#endif > + > + > static struct dev_pm_ops omap_i2c_pm_ops = { > + SET_SYSTEM_SLEEP_PM_OPS(omap_i2c_suspend, omap_i2c_resume) > SET_RUNTIME_PM_OPS(omap_i2c_runtime_suspend, > omap_i2c_runtime_resume, NULL) > }; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/